REFRIGERATOR AND METHOD FOR CONTROLLING THE SAME

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0184453, filed on Dec. 12, 2024, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

The present invention relates to a refrigerator and a method for controlling the same, and more particularly, to a refrigerator including a distance sensing sensor and a method for controlling the same.

A refrigerator is a home appliance that supplies cold air generated by utilizing the circulation of refrigerant to a storage chamber, thereby keeping various types of storage objects fresh for a long period of time. The cold air supplied to the refrigerator can be generated by taking away heat from the inside of the refrigerator as the refrigerant circulating through the compressor, condenser, and evaporator in this order flows into the evaporator, so that the liquid refrigerant is vaporized into the gaseous refrigerant.

In general, the refrigerator may include a cabinet forming a storage chamber, and a door provided in the cabinet to open or close the storage chamber. For example, the door may be opened or closed, for example, in a manner of a rotary door or a drawer-type door. The rotary door may be connected to one side of the cabinet so as to be rotatable about an axis, so that the storage chamber can be opened or closed by rotating it. The drawer-type door may be provided to be inserted or withdrawn in the front and rear direction of the cabinet, so that the storage chamber can be opened or closed by withdrawing or inserting it.

The drawer-type door may include a door part covering the front side of the storage chamber, and a storage part provided in the rear side of the door part to have a storage space therein for storing storage goods. The storage space of the drawer-type door may be exposed to the outside by a user's withdrawal operation, for example, by a user pushing or pulling the door. Drawer-type doors are preferred by many users because they can facilitate space utilization when a user organizes or takes out foodstuffs.

For example, the drawer-type door may be provided in the lower region of the cabinet. As in this case, when the drawer-type door is provided in the lower region of the cabinet, there is an inconvenience in that it is difficult for a user to manipulate it because the user has to bend down to pull out the drawer-type door. To address such a drawback, it is under development to equip a refrigerator with a automatic door opening and closing module allowing for automatic insertion and withdrawal of the drawer-type door by driving an electric motor.

For example, the automatic door opening and closing module enable the automatic opening or closing of a drawer-type door in a sliding manner along guide rails mounted in the inner side of a storage chamber. The foregoing refrigerator including the automatic door opening and closing module that automatically inserts and withdraws the drawer-type door adopts various sensors and control systems to maximize user convenience.

To the refrigerator including the drawer-type door that can be automatically inserted or withdrawn, obstacle sensing sensors may be added to sense obstacles located in the movement direction of the drawer-type door. These obstacle sensing sensors may sense whether there is an obstacle within a certain distance in the process of opening or closing the drawer-type door, and may stop the movement of the door to avoid a collision.

Meanwhile, in the refrigerator having the drawer-type door, the obstacle sensing sensor may be installed in another door located above the drawer-type door or in the upper region of the drawer-type door. In the case where the obstacle sensing sensor is located in this way, it can excellently sense an obstacle corresponding to the upper region of the drawer-type door, but there is a limit to sensing an obstacle corresponding to the lower region. This means that there is a risk of colliding with a user or an object when the door moves because the sensor fails to recognize obstacles near the lower region of the door or the floor surface.

For example, when a user is standing in front of a door, the lower part of the body, such as the foot, is placed in the sensing blind spot of the sensor. Among the user's body parts, the foot is located foremost, and so, when the user stands facing the front surface of the refrigerator, the user's foot is located closest to the door. At this time, if the user's foot is placed in the sensing blind spot of the sensor, it may cause a safety accident in a situation where the drawer-type door is automatically opened or closed. Additionally, if a companion animal or an infant is moving near the floor surface in front of the refrigerator, they are also outside the sensor's sensing range, which may pose an accident risk.

Besides, with regard to the automatic opening or closing of the drawer-type door, it is a usual pattern that the door is opened or closed in its entirety. This may cause a problem that cold air inside the refrigerator is unnecessarily lost to the outside by opening the entire drawer-type door even when only some of the items stored inside the drawer-type door are required. This leads to a decrease in the energy efficiency of the refrigerator, and to an increase in power consumption.

Moreover, it is common that the drawer-type door requires the user to input a physical signal manually to close the door. In general, this physical signal input part is located in an upper region of the refrigerator, such as an upper door of the refrigerator. Because of this, there is an inconvenience that the user has to straighten his or her waist again while holding the items to input a closing signal through the physical signal input part in order to close the drawer-type door again after the user has bent down to take out the necessary items from the drawer-type door located in the lower region.

Besides, in the case of operating the overall opening and closing of the drawer-type door, there is a problem that, even when the user has to organize items or maintain the drawer-type door in an opened state temporarily, an additional action, which otherwise would be unnecessary, is required, which, in turn, degrades the user experience.

Additionally, if the operation stops only when a collision with an external object occurs in the process of opening or closing the drawer-type door, the door or object may be damaged, or the motor of the automatic door opening and closing module may be damaged due to an overload occurring therein. Therefore, it is necessary to prevent damage to the refrigerator and object, not only when a collision occurs in the process of the insertion or withdrawal process of the drawer-type door, but also by sensing the danger before the collision occurs.

In order to solve the above problems, the present invention proposes a refrigerator and a method of controlling the same as follows.

SUMMARY

The purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to increase stability by reducing the blind spot of the distance sensing sensor.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to prevent a collision between a door and an obstacle in advance.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to prevent a collision with an obstacle or react quickly to the collision in the process of opening the door.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to minimize the cold air loss caused by a door opening mode and provide user-customized convenience.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible for a user to manipulate door closing without taking an additional action of straightening his or her waist.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to reduce damage to the automatic door opening and closing module by external impact.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to reduce the damage to the distance sensing sensor by external impact.

Additionally, the purpose of the present invention is to provide a refrigerator and a method for controlling the same, in which it is possible to prevent damage to the door by reacting quickly even if the user closes the door by mistake or the object is caught unintentionally.

The purposes of the present invention are not limited to the purposes mentioned above, and other purposes and advantages of the present invention which are not mentioned can be appreciated from the following description, and will be more clearly appreciated by the embodiments of the present invention. Furthermore, it is readily understood that the objects and advantages of the present invention can be achieved by the means set forth in the claims and combinations thereof.

A refrigerator according to an embodiment of the present invention for accomplishing above-described purpose includes a cabinet including an upper storage chamber and a lower storage chamber, a door opening or closing a front side of the lower storage chamber in a sliding movement manner in a front and rear direction, one or more distance sensing sensors disposed in a lower region of the door and measuring a separation distance from a sensing target, a automatic door opening and closing module driven to insert or withdraw the door automatically, and a controller controlling operation of the automatic door opening and closing module based on the separation distance from the sensing target.

The separation distance from the sensing target may be a distance from a front surface of the door to the sensing target.

In a case where the sensing target is a user, the distance sensing sensor may have a sensing field of view allowing for sensing a foot of the user.

The distance sensing sensor may be disposed in the door at such a height so as to be overlapped with the foot or an ankle of the user in a front and rear direction.

In a case where the separation distance from the sensing target is measured as exceeding a preset safety distance, the controller may control such that the door is opened.

While the door is being opened, the distance sensing sensor may continuously measure the separation distance from the sensing target.

While the door is being opened, in a case where the separation distance from the sensing target is measured to be less than or equal to a preset safety distance, or in a case where an impact is detected on the automatic door opening and closing module, the controller may control such that a driving of the automatic door opening and closing module is stopped.

The refrigerator may further include an opening signal input part activating the opening mode of the door, wherein, in a case where an opening mode signal of the door is input to the opening signal input part, a sensing function of the distance sensing sensor may be activated.

An opening mode of the door may include a first opening mode of opening the door to a maximum, wherein, in the first opening mode, in a case where a driving time of the automatic door opening and closing module exceeds a preset door maximum opening reaching time, or in a case where the door reaches a door maximum opening distance, the controller may controls such that a driving of the automatic door opening and closing module is stopped.

Wherein an opening mode of the door may include a second opening mode of opening the door partially, wherein, in the second opening mode, in a case where a driving time of the automatic door opening and closing module exceeds a preset door partial opening reaching time, the controller may controls such that a driving of the automatic door opening and closing module is stopped.

The refrigerator may further include a closing signal input part activating a closing mode of the door, wherein, while the door is in a state of being opened, in a case where a closing mode signal of the door is input to the closing signal input part, the controller may control the door to be closed.

The closing signal input part may be located in an upper region of the door.

The refrigerator may further include a hold signal input part stopping movement of the door in a state where the door is opened, wherein the hold signal input part may be located in an upper region of the door.

In a state where a hold mode signal of the door is input to the hold signal input part, in a case where the closing mode of the door is activated, the controller may control such that a state in which the movement of the door is stopped is maintained.

In a state where a hold mode signal of the door is input to the hold signal input part, in a case where the hold mode signal is additionally input, or in a case where a preset door hold duration time has elapsed, the controller may control such that the door is closed.

While the door is being closed, in a case where an impact is detected on the automatic door opening and closing module, the controller may control such that an opening mode of the door is implemented.

Further, as a method for controlling a refrigerator according to an embodiment of the present invention for accomplishing the above-described purposes, a method for controlling a refrigerator, which includes a door automatically opening or closing a front side of a storage chamber, and one or more distance sensing sensors disposed in a lower region of the door and measuring a separation distance from a sensing target, may include an opening mode start step in which an opening mode of the door is started, and a door automatic opening step in which, in a case where the separation distance from the sensing target exceeds a preset safety distance, the door is opened.

In a case where the sensing target is a user, the distance sensing sensor may have a sensing field of view allowing for sensing a foot of the user.

The method may further include: while the door is being opened, in a case where the separation distance from the sensing target is measured to be less than or equal to a preset safety distance, or in a case where an impact is detected on the door, in a case where an opening time of the door exceeds a preset door opening reaching time, or in a case where the door reaches a preset door opening distance, an opening mode stopping step in which the opening mode of the door is interrupted.

The method may further include a closing mode start step in which, after the opening mode stopping step, a closing mode of the door is started, a door hold step of maintaining a state in which movement of the door is stopped, and a door automatic closing step in which the door is closed in a case where, after the door hold step has been performed, the door hold step is released.

In the door automatic closing step, in a case where an impact is detected on the door, the door automatic closing step may be shifted to the door automatic opening step.

The refrigerator and the method for controlling the same according to the present invention can sense even lower obstacles, including the user's foot, by disposing one or more distance sensing sensors in the lower region of the door. Through this, it is possible to significantly improve the safety of the user and the refrigerator because when the user uses the door, it is possible to prevent an accident in which an object near the floor, such as an infant, a companion animal, and a foot of the user, collides with the door.

Additionally, the refrigerator and the method for controlling the same according to the invention can provide both convenience and safety of the user by automatically opening the door while maintaining a safety distance from surrounding objects by controlling such that the door is opened when the separation distance from the sensing target measured by the distance sensing sensor exceeds a preset safety distance.

Additionally, the refrigerator and the method for controlling the same according to the invention can prevent unexpected collisions and maximize safety during use because while the door is being opened, the distance sensing sensor can continuously measure the separation distance to enable a quick reaction even if a new obstacle is sensed in the process of the opening of the door.

Additionally, the refrigerator and the method for controlling the same according to the invention can be controlled such that the door is automatically stopped when the sensing sensor recognizes an object while the door is being opened or closed. Accordingly, it is possible to ensure user safety by preventing an unexpected collision that may occur in the process of opening or closing the door.

Additionally, the refrigerator and the method for controlling the same according to the invention can activate the sensing function of the distance sensing sensor when the opening mode signal is input to the opening signal input part, since the user provides an opening signal input part for intentionally opening the door. Through this, it is possible to reduce unnecessary energy consumption and improve the user experience by controlling such that the door is opened only when the user wishes.

Additionally, the refrigerator and the method for controlling the same according to the invention can adjust the opening mode of the door including the first opening mode in which the door is opened to the maximum and the second opening mode in which it is opened partially, according to the user's selection. As described above, by selectively providing the function to open the door as much as the user needs, it is possible to minimize cold air loss and increase energy efficiency, and by supporting the Quick Zone use mode for quickly taking out items, it is possible to greatly increase user convenience.

Additionally, the refrigerator and the method for controlling the same according to the present invention can allow the user to easily manipulate the closing of the door without the user taking an additional action of straightening his or her waist, by positioning the closing button on the upper region of the door.

Additionally, the refrigerator and the method for controlling the same according to the present invention can prevent additional damage, because the controller controls such that the operation of the door is stopped or changed to the opening mode when an abnormal impact is detected while the door is being closed. Accordingly, it is possible to ensure the user safety and extend the life of the refrigerator.

Additionally, the refrigerator and the method for controlling the same according to the present invention can enhance the safety of the user and the product because the electric current change in the driving unit of the automatic door opening and closing module can be continuously monitored, so that, when an abnormal load or impact is sensed, it is possible to immediately stop or reverse the operation of the door.

Additionally, the refrigerator and the method for controlling the same according to the present invention provide a hold function of temporarily stopping the movement of the door according to the user's intention, and the hold signal input part for this is located in the upper region of the door, so that it is possible to improve user convenience. Therefore, the user can set the door to stop when the door is opened or closed as much as he/she wants, so that it is possible to fix the door at a desired position while taking out or organizing specific items. This can greatly improve user's convenience, and minimize inconvenience which may be caused when handling the door.

Additionally, the refrigerator and the method for controlling the same according to the present invention may prevent an impact from the outside and prevent damage caused by surrounding objects such as a vacuum cleaner or a cleaning robot, by installing the distance sensing sensor to be disposed in a lower region of the door and in the rear side of the front surface of the door. Through this, it is possible to prevent damage of the door sensing sensor and to enhance reliability of the product by reducing unexpected problems that may occur in the process of opening or closing the door.

Additionally, the refrigerator and the method for controlling the same according to the present invention can allow the user to set an opening mode or a closing mode of the door as the user wishes through a user-customized control function. Accordingly, in the automatic door closing step, when an impact is detected on the door, it can be changed to the opening step to ensure user safety, allowing the user to easily control the closing mode of the door. Through this, it is possible to react quickly even when the user closes the door by mistake or an object is unintentionally caught, thereby preventing the damage.

In addition to the effects described above, specific effects of the present invention will be described below together with specific matters for practicing the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front perspective view of a refrigerator with the doors closed.

FIG. 2 is a front perspective view of a refrigerator with a third door opened in a first opening mode.

FIG. 3 is a side cross-sectional view of a refrigerator with a third door opened.

FIG. 4 illustrates an electric wire guide module and a automatic door opening and closing module which are disposed in a rear side of a third door.

FIG. 5 shows a front perspective view of a refrigerator with a third door opened in a second opening mode, and enlarged views of partial regions thereof.

FIGS. 6 and 7 are respectively a perspective view from a side direction of a refrigerator and a plan view thereof, with a third door opened in a second opening mode.

FIG. 8 is a block diagram of a control signal controlled by a controller.

FIG. 9 is a front view of a refrigerator with the doors closed.

FIG. 10 is a side view showing a sensing field of view of a distance sensing sensor part installed in a lower region of a third door of a refrigerator.

FIG. 11 is an enlarged side view of a distance sensing sensor part installed at a lower end of the third door.

FIG. 12 is an exploded perspective view of a distance sensing sensor part.

FIG. 13 is a side cross-sectional view of a distance sensing sensor part installed in a lower portion of a third door.

FIG. 14 is a flowchart of a control method for a door automatic first opening mode.

FIG. 15 is a flowchart of a control method for a door automatic second opening mode.

FIG. 16 is a flowchart of a control method for a door closing mode.

DETAILED DESCRIPTION

The purposes, features and advantages described above will be described in detail below with reference to the accompanying drawings, so that a person having ordinary knowledge in the technical field to which the present invention pertains can easily practice the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference symbols are used to refer to like or similar components.

Although the terms “first”, “second”, and so on are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another component, and unless specifically stated to the contrary, it should be understood that a first component may also be a second component.

Throughout the specification, unless specifically stated to the contrary, each element may be singular or plural.

Hereinafter, the phrase “any configuration is disposed in the upper side of (or in the lower side of) a component” or “on (or below) a component” may mean not only that any configuration is disposed in contact with the upper surface (or lower surface) of said component, but also that another configuration may be interposed between said component and any configuration disposed on (or below) said component.

Additionally, when a component is described as being “connected,” “coupled,” or “contacted” to another component, it should be understood that although the both components may be directly connected, coupled or contacted to each other, a third component may also be “interposed” between the both components, or the both components may be “connected,” “coupled,” or “contacted” to each other through a third component.

As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. Herein, the terms “be comprised of” or “comprise” should not be construed to necessarily include all of the various components or various steps described in the specification, and should be construed to mean that some of the components or some of the steps may not be included, or that additional components or steps may be included.

Throughout the disclosure, the phrase “A and/or B” means A, B, or A and B, unless otherwise specified, and the phrase “C to D” means equal to or greater than C and equal to or smaller than D unless otherwise specified.

Hereinafter, a refrigerator according to some embodiments of the present invention will be described.

[The Structure of a Refrigerator]

A refrigerator according to an embodiment of the present invention will be described with reference to FIGS. 1 to 8.

Referring to FIGS. 1 to 4, the exterior of a refrigerator 1 may be formed by a cabinet 2 with one or more storage chambers included therein, which are storage spaces for goods, and a plurality of doors 10, 20, and 30 capable of opening and closing the open front side of the cabinet 2. The cabinet 2 may include an outer case 3 and an inner case 4 coupled to the inner side of the outer case 3. Between the inner case 4 and the outer case 3, there may be formed an insulation region in which the insulation material is filled, and through which various ducts related to the cold air system pass.

The inner case 4 may be partitioned into separate spaces to include a plurality of storage chambers. For example, the storage chambers may include a first storage chamber 5, a second storage chamber 6, and a third storage chamber 7. The first storage chamber 5 may be disposed in the upper portion; the second storage chamber 6 may be disposed at the middle portion; and the third storage chamber 7 may be disposed at the lower portion. Although the present specification illustrates, by way of example, that three storage chambers are stacked in an up and down direction, the number and positions of the storage chambers are not limited to this. For example, the first storage chamber 5 functions as a refrigerating chamber; the second storage chamber 6 functions as a refrigerating chamber, a freezing chamber, or a switchable chamber having a desired temperature according to user settings; and the third storage chamber 7 functions as a freezing chamber, but the function of each storage chamber is not limited to this.

The first storage chamber 5 may be opened or closed by the first door 10. There may be provided a pair of first doors 10, which may be rotary doors, respectively, connected rotatably through hinges to one side and the other side of the cabinet 2 constituting the first storage chamber 5. In the front surface of each of the first doors 10, a transparent part 11 may be formed, through which the inside of the first storage chamber 5 can be viewed without opening the first door 10. For example, a region of the first door 10 corresponding to the transparent part 11 is formed of a transparent material such as glass, so that it can be in a transparent state. Further, the transparent part 11 may be formed of a material having selectively-controllable transmittance and reflectance of light, so that it can be configured to allow for the selective adjustment of transparent or opaque state according to the user's manipulation.

On the front surface of the first door 10, one or more first input parts 13 may be disposed. For example, the first input part 13 may include a touch panel allowing for the command input by a user's touch input, or may be a display unit including a display panel for outputting a screen. The display unit is for displaying and manipulating the operation state of the refrigerator 1, and allows the user to identify various types of information from the outside. The display unit may be provided with a display screen for displaying state information of the refrigerator 1 and various operation buttons for setting the operation of the refrigerator 1.

For example, the first input part 13 may be disposed in the transparent part 11 of the first door 10. When the transparent part 11 is in a transparent state, the first input part 13 may also be in a visible state to display the operation state of the refrigerator 1 to the outside. Additionally, the first input part 13 may be disposed in the front surface of the first door 10 so as to be disposed in the outside of the transparent part 11. In this case, the first input part 13 may be provided as, but is not limited to, a display unit, and may be provided in the form of a touch unit or in the form of a button part that can be pressed in a physical manner.

Additionally, the first input part 13 may be provided in the form of a microphone that recognizes a user's voice command. For example, when a preset specific command is input to the first input part 13, the first input part 13 may recognize this and transmit an input signal to a controller of the refrigerator 1. The first input part 13 may be used to activate a sensing function of a distance sensing sensor 120 to be described later, and the detailed description thereof will be provided later.

Meanwhile, in the front surface of the first door 10, one or more first sensor parts 12 may be disposed. For example, in the lower side of the transparent part 11 of each of the first doors 10, one or more first sensor parts 12 may be disposed. The first sensor part 12 may be mounted in the inner side of the first door 10, and in the case where the front surface of the first door 10 is made of a transparent material such as glass, the position of the first sensor part 12 can be exposed to the outside. As the first sensor part 12 is disposed in the lower region of the first door 10, the first sensor part 12 may be located in an approximately central region with respect to the entire height of the refrigerator 1. It may be preferable, in order to prevent a malfunction caused by interference with the distance sensing sensor 120 of the third door 30 to be described later, that the first sensor part 12 is located in the first door 10 located above the third door 30. The first sensor part 12 may be a proximity sensing sensor capable of sensing the proximity of a sensing target located in front of the refrigerator 1. The first sensor part 12 may be used to activate a sensing function of the distance sensing sensor 120 to be described later.

For example, the first sensor part 12 may be a position sensitive detector (PSD) sensor. The PSD sensor is a position sensing sensor using a light source. The PSD sensor, which is an optical sensor used to measure the position of incident light, can identify the position of the sensing target by measuring the distribution of electric current generated when light or particles hit the sensor surface. The PSD sensor may be referred to as a position sensing sensor or an optical position detector.

As another example, the first sensor part 12 may be a time of flight (TOF) sensor. The TOF sensor is a sensor that calculates distance by emitting light of a specific wavelength and measuring the time it takes for the light to be reflected and returned. By precisely measuring the round trip time of light, the TOF sensor can calculate the distance between the object and the sensor in real time using the time it takes for the light to be reflected and returned.

As another example, the first sensor part 12 may be an ultrasonic sensor. The ultrasonic sensor is a sensor that measures a distance by emitting sound waves and receiving reflection waves reflected by and returned from an object. The ultrasonic sensor may accurately calculate a distance to an object by measuring a time between the transmitted sound wave and the received reflection wave.

As another example, the first sensor part 12 may be a radar sensor. The radar sensor may operate such that it calculates the distance to the object by emitting radio waves and receiving reflection waves to measure the time difference of the radio waves. The radar sensor may monitor various information such as the angle, position, and speed of the object by using the phase difference between the transmission signal and the reflection wave.

As another example, the first sensor part 12 may be a lidar sensor. The lidar sensor is a sensor that calculates a distance by measuring the time it takes for the emitted laser light to be reflected by and returned from an object through the time of flight (TOF) principle. The lidar sensor may recognize a sensor value for the surrounding environment while rotating 360 degrees using a motor.

As another example, the first sensor part 12 may be a heat sensing sensor. The heat sensing sensor is a sensor that senses heat emitted from a human body or object and identifies the location of the object. Since the heat sensing sensor senses an object using infrared radiation energy with no use of light, it can work effectively even in dark environments.

As another example, the first sensor part 12 may be a motion sensing sensor capable of recognizing a gesture such as a specific movement of the user. When the first sensor part 12 recognizes a specific movement of the user, the sensing function of the distance sensing sensor 120 can be activated.

The third storage chamber 7 may be opened or closed by the third door 30. The third door 30 may be a drawer-type door that is opened or closed in a draw-out or push-in manner in the front and rear direction. As denoted in the present specification, the front and rear direction means a direction based on the front and rear of the refrigerator 1, and the left and right direction means a direction based on both lateral sides of the refrigerator 1. The front of the refrigerator 1 refers to a direction where the user uses the refrigerator 1. The third door 30 may include a door part 31 covering the front side of the third storage chamber 7, and a storage part 32 provided in the rear side of the door part 31 and accommodated in the third storage chamber 7. In the upper portion or lower portion of the door part 31, a handle may be formed so as to be recessed in the inner direction of the door part 31 so that the user can easily open or close the door part 31.

The storage part 32 may be formed in the form of a basket provided with a storage space in which storage items such as food are stored. The storage part 32 may be formed in a separation type so as to be separable from the door part 31. For example, the storage part 32 may be fixed in the rear side of the door part 31 by being fastened or seated on a separate connection member such as a bracket member, to which, however, the present invention is not limited, and it may also be directly fastened and fixed to the rear surface of the door part 31.

In the third storage chamber 7, a pair of guide rails 33 may be disposed on both lateral sides of the storage part 32, respectively, to guide the insertion or withdrawal of the storage part 32 in the front and rear direction of the third door 30. The guide rail 33 may be implemented as a rail assembly including a multi-stage rail unit whose length is extended and retracted in the front and rear direction.

In the third storage chamber 7, a automatic door opening and closing module 43 may be disposed to provide a driving force to the third door 30 and move the third door 30 in the front and rear direction so that the third door 30 can be automatically inserted or withdrawn. For example, the automatic door opening and closing module 43 may be disposed at the lower portion of the third storage chamber 7, to which, however, the present invention is not limited, and it may also be disposed on the side surface of the third storage chamber 7.

As an example, the automatic door opening and closing module 43 may be disposed in the lower portion of the third storage chamber 7, and may include a pinion gear 44 and a driving unit 46. The pinion gear 44 may be installed to penetrate the lower surface of the third storage chamber 7 upward to be exposed into the third storage chamber 7, and the driving unit 46 may be disposed in the lower side of the third storage chamber 7 so that it may be connected with the pinion gear 44 to transmit power to the pinion gear 44. The driving unit 46 may be a driving motor. There may be provided a pair of pinion gears 44, which may be disposed on both sides of the lower surface of the third storage chamber 7 in the left and right direction, respectively. For example, the pair of pinion gears 44 may be connected to each other by a power transmission bar extending in the left and right direction of the third storage chamber 7. Therefore, even when the driving force of the driving unit 46 is provided to one pinion gear 44, the pair of pinion gears 44 can be rotated simultaneously in synchronization with each other by the power transmission bar to have the same driving speed and the same rotation direction.

The automatic door opening and closing module 43 may include a rack gear assembly 45 disposed to be engaged with the pinion gear 44. The rack gear assembly 45 may be a multi-stage type including a plurality of gear racks that move so that the length thereof is extended and retracted in the front and rear direction. The rack gear assembly 45 may be formed to be extended in the front and rear direction, and may be driven in a rack pinion driving manner together with the pinion gear 44. There may be provided a pair of rack gear assemblies 45 which are disposed to be engage with the pinion gears 44 and are connected to both lower outer surfaces of the storage part 32, respectively. When the pinion gear 44 is rotated by the driving of the driving unit 46, the gear racks constituting the rack gear assembly 45 can be inserted or withdrawn in the front and rear direction. According to this movement of the rack gear assembly 45 in the front and rear direction, the storage part 32 connected to the rack gear assembly 45 can also be inserted or withdrawn in a sliding manner in the front and rear direction. The automatic door opening and closing module 43 as described above is an example, and the method or position thereof is not limited to this, and may be implemented in various ways.

Referring further to FIGS. 5 to 7, in the third door 30, the second input part 51 may be located. The second input part 51 may be a closing signal input part for activating the closing mode of the third door 30. When the closing mode is activated, the third door 30 can be retracted toward the rear to be closed. The second input part 51 may be located in an upper region of the third door 30. For example, the second input part 51 may be located on the upper surface of the third door 30. Therefore, when the third door 30 is in a completely closed state, the second input part 51 is not exposed to the outside, whereas, when the third door 30 is in an opened state, the second input part 51 can be exposed to the outside. The second input part 51 may be configured in a touch manner to recognize a user's touch, or in a button manner to allow the user to physically press, to which, however, the present invention is not limited. The second input part 51 may be disposed to be close to one lateral side of the upper surface of the third door 30, to which, however, the present invention is not limited.

Since the second input part 51 is located in the third door 30, the second input part 51 can also be moved when the third door 30 is moved. If the second input part 51 is located in the first door 10 or the second door 20 other than the third door 30, when the third door 30 is withdrawn forward, the distance between the user and the second input part 51 may be increased by the distance of the withdrawn third door 30. Thereby, it may become difficult for the user to manipulate the second input part 51. However, when the second input part 51 is located in the third door 30, the user can always maintain a constant distance from the second input part 51 without being affected by the insertion or withdrawal distance of the third door 30. Therefore, the user can always maintain a close constant distance within which to manipulate the second input part 51 with ease.

Additionally, since the second input part 51 is located in the upper region of the third door 30, the user can easily manipulate the second input part 51 while in the state of crouching or bending forward to take out the item stored in the third door 30 or put an item thereinto. That is, since the closing button of the third door 30 is located in the upper region of the third door 30, the user can easily manipulate the closing of the third door 30 without the additional action of straightening his or her waist.

Additionally, in the third door 30, a third input part 52 may be located. The third input part 52 may be a hold signal input part for activating a hold mode of the third door 30. When the hold mode is activated, the third door 30 may maintain a state in which the movement is stopped without advancing forward or retreating rearward. The third input part 52 may be located in the upper region of the third door 30. For example, the third input part 52 may be located on the upper surface of the third door 30. Therefore, when the third door 30 is in a completely closed state, the third input part 52 is not exposed to the outside, whereas, when the third door 30 is in an opened state, the third input part 52 can be exposed to the outside. The third input part 52 may be configured in a touch manner to recognize a user's touch, or in a button manner to allow the user to physically press, to which, however, the present invention is not limited. The third input part 52 may be disposed to be close to the other side of the upper surface of the third door 30 opposite to the one side where the second input part 51 is located, to which, however, the present invention is not limited.

Since the third input part 52 is located in the third door 30, the third input part 52 can also be moved when the third door 30 is moved. If the third input part 52 is located in the first door 10 or the second door 20 other than the third door 30, when the third door 30 is withdrawn forward, the distance between the user and the third input part 52 may be increased by the distance of the withdrawn third door 30. Thereby, it may become difficult for the user to manipulate the third input part 52. However, when the third input part 52 is located in the third door 30, the user can always maintain a constant distance from the third input part 51 without being affected by the insertion or withdrawal distance of the third door 30. Therefore, the user can always maintain a close constant distance within which to manipulate the third input part 52 with ease.

Additionally, since the third input part 52 is located in the upper region of the third door 30, the user can easily manipulate the third input part 52 while in the state of crouching or bending forward to take out the item stored in the third door 30 or put an item thereinto. That is, since the hold button of the third door 30 is located in the upper region of the third door 30, the user can easily manipulate the stop of the movement of the third door 30 without the additional action of straightening his or her waist.

In the third storage chamber 7, a drawer part 40 may be additionally disposed. The drawer part 40 may be disposed above the storage part 32. The door part 31 may be formed to have such a size that it can substantially cover the front surfaces of the storage part 32 and the drawer part 40. For example, the drawer part 40 may be inserted or withdrawn in the front and rear direction without being restricted by the movement of the storage part 32. For example, the drawer part 40 may be inserted or withdrawn in the front and rear direction by means of rollers which roll along the upper surfaces of the edge portions of both sides of the storage part 32. However, this is not exhaustive, and the drawer part 40 may be guided to move in the front and rear direction by separate guide rail members disposed on the side surfaces of the third storage chamber 7. Besides, there may be provided a pair of drawer parts 40 disposed side by side in the left and right direction.

Referring to FIG. 5, in the third storage chamber 7, an ice maker may be disposed. The ice maker may include a first ice maker 41 and a second ice maker 42. The first ice maker 41 and the second ice maker 42 may be mounted in the inner side of the upper surface of the third storage chamber 7. The first ice maker 41 and the second ice maker 42 may be positioned so as to be accommodated inside the drawer part 40, so that the front surfaces of the first ice maker 41 and the second ice maker 42 may be covered by the drawer part 40 when the drawer part 40 is in a closed state.

The second storage chamber 6 may be opened or closed by the second door 20. The second door 20 may be a drawer-type door that can be opened or closed in a draw-out or push-in manner in the front and rear direction. For example, in a same manner as the third door 30, the second door 20 may also include a door part covering the front side of the second storage chamber 6, and a storage part provided in the rear side of the door part and accommodated in the second storage chamber 6, to which, however, the present invention is not limited. In the second storage chamber 6, a automatic door opening and closing module 43 may be disposed to automatically insert or withdraw the second door 20 in the front and rear direction. For example, the automatic door opening and closing module 43 may be disposed at the lower portion of the second storage chamber 6, to which, however, the present invention is not limited, and it may also be disposed on the side surface of the third storage chamber 7.

On the outer side of the lower end of the cabinet 2, one or more wheel parts 9 may be disposed. For example, the wheel parts 9 may be formed at four corners on the outer side of the lower end of the cabinet 2 to assist the user in moving the refrigerator 1 with ease. Additionally, on the outer side of the lower end of the cabinet 2, one or more height adjustment parts 8 may be disposed. For example, the height adjustment parts 8 may be formed in two corner portions in the front outer side of the lower end of the cabinet 2. For example, the height adjustment part 8 may be implemented such that, depending on which direction to rotate it, the height of the refrigerator 1 in the up and down direction can be increased or decreased. The height adjustment part 8 together with the wheel part 9 may be in contact with the floor surface by which the refrigerator 1 is supported, and, depending on the adjusted height, only the wheel part 9 may be in contact with the floor surface while the height adjustment part 8 may not be in contact with the floor surface. When the height adjustment part 8 together with the wheel part 9 is in contact with the floor surface, movement of the refrigerator 1 by the wheel part 9 may be restricted due to friction between the height adjustment part 8 and the floor surface.

In this way, as the lower surface of the cabinet 2 of the refrigerator 1 is supported by the wheel part 9 or the height adjustment part 8, which has a predetermined height, the lower surface of the cabinet 2 can be disposed to be spaced by a predetermined distance from the floor surface on which the refrigerator 1 is installed. Besides, the lower surface of the third door 30 of the plurality of doors, which is located at the lowermost portion, may also be disposed to be spaced by a predetermined distance, by the wheel part 9 or the height adjustment part 8, from the floor surface on which the refrigerator 1 is installed. For example, the lower surface of the cabinet 2 and the lower surface of the third door 30 may be formed at the same height, to which, however, the present invention is not limited. Referring further to FIG. 11, the lower surface of the third door 30 may be formed to be higher than the lower surface of the cabinet 2 by a predetermined distance in the up direction. Therefore, the distance between the floor surface and the lower surface of the third door 30 may be at least equal to or greater than the height of the wheel part 9 or the height of the height adjustment part 8. At the lower end of the third door 30, the distance sensing sensor part 100 may be disposed, which is formed to protrude downward, and the detailed description of the distance sensing sensor part 100 will be provided later.

Referring to FIG. 4, in the rear side of the third door 30, an electric wire guide module 70 may be disposed. The electric wire guide module 70 may be disposed on the lower surface of the third storage chamber 7 to be connected with the door part 31 of the third door 30. Among various power lines or various electric wires connected along the lower surface of the third storage chamber 7, the electric wire guide module 70 is configured to protect power lines and electric wires connected to electronic components in the door part 31. For example, the electric wire guide module 70 may protect the power lines and electric wires connected to the distance sensing sensor part 100 mounted in the third door 30. The electric wire guide module 70 may be configured to prevent electric wires from being damaged by twist or scratch, while guiding the electric wires to be moved together with the third door 30 during its forward or rearward movement.

For example, the electric wire guide module 70 may be configured to include a cover plate 73, a guide head 72, and a connecting member 71. The guide head 72 may be coupled to the rear surface of the door part 31 of the third door 30. Along a rear perimeter portion of the door part 31, a gasket part 38 may be formed. In a rear central region of the lower portion of the gasket part 38 of the door part 31, the guide head 72 may be disposed to be connected with the rear surface of the door part 31. One side of the connecting member 71 may be connected to the cover plate 73 to be rotatable in the horizontal direction around one axis. The other side of the connecting member 71 may be connected with the guide head 72. For example, a plurality of connecting members 71 may be formed as hollow tubular bodies, which are connected to each other continuously in the form of a chain-type connection structure, so that electric wires can be installed to pass through each of the connecting members 71 sequentially. By this connection structure of the connecting members 71 and the guide head 72, the connecting members 71 can be moved in linkage with the forward or rearward movement of the third door 30 while moving the electric wires together. On the cover plate 73, the automatic door opening and closing module 43 may also be mounted, to which, however, the present invention is not limited, and the cover plate 73 may function as a cover member covering an upper surface of the automatic door opening and closing module 43.

The third door 30 according to the present invention may be implemented such that it can be opened in various opening modes in the case where it is automatically inserted or withdrawn by the automatic door opening and closing module 43. For example, the opening mode of the third door 30 may include a first opening mode and a second opening mode. The first opening mode may be set as a mode in which the third door 30 is opened to the maximum, and the second opening mode may be set as a mode in which the third door 30 is not opened to the maximum, but partially. For example, FIGS. 2 and 3 illustrate a state in which the third door 30 is opened in the first opening mode. In this way, when the third door 30 is opened in the first opening mode, the third door 30 may be drawn out forward to the maximum. Thereby, the door part 31 and the storage part 32 are also drawn out forward to the maximum, so that the storage part 32 may be completely exposed to the outside. In the front inner side of the storage part 32, a storage container 34 may be seated, which is provided separately from the storage part 32. Therefore, in the first opening mode, the storage container 34 may also be completely exposed to the outside. In order to implement the first opening mode, the door withdrawal module 43 for automatically inserting or withdrawing the third door 30 may be operated such that its operation range corresponds to the maximum withdrawal mode. FIGS. 5, 6, and 7 illustrate a state in which the third door 30 is opened in the second opening mode. In this way, when the third door 30 is opened in the second opening mode, the third door 30 may not be drawn out forward to the maximum, but opened partially. The distance by which the third door 30 is opened in the second opening mode may be set previously.

The storage part 32 may be subdivided into storage zones by one or more partitions 37. The storage part 32 may include a front storage zone 35 and a rear storage zone 36, which are disposed to be distinguished in the front and rear direction. In the storage part 32, a first partition 37a may be formed to extend in the left and right direction of the storage part 32 and partition the storage part 32 in the front and rear direction, so that the front storage zone 35 and the rear storage zone 36 can be partitioned. The width of the front storage zone 35 in the front and rear direction may be formed to be smaller than the width of the rear storage zone 36 in the front and rear direction. In the storage part 32, a second partition 37b may be formed to extend in the front and rear direction and partition the storage part 32 in the left and right direction, so that each of the front storage zone 35 and the rear storage zone 36 can be partitioned into a plurality of zones. In the front storage zone 35, the storage container 34 may be seated to be disposed in the storage part 32. The storage container 34 may be taken out or put in personally by the user. However, this is not exhaustive, and if necessary, an elevation module for automatically lifting and lowering the storage container 34 may be mounted in the third door 30 to automatically lift or lower the storage container 34, thereby improving the user's convenience. In the case where the front storage zone 35 is divided into a plurality of zones, the storage container 34 may be seated in each of the divided front storage zones 35.

In the second opening mode, the third door 30 may be set to be drawn out forward at least by such a distance that the front storage zone 35 can be exposed to the outside. When the front storage zone 35 is exposed to the outside, the storage container 34 can also be exposed to the outside. In other words, when the storage container 34 that can be taken out or put in the vertical direction is exposed to the outside, the user can easily take out the item stored in the storage container 34 or store the item in the storage container 34 even without fully opening the third door 30. To this end, in the second opening mode, it is preferable that the third door 30 is drawn out forward at least by a width greater than the sum of the width of the door part 31 in the front and rear direction and the width of the storage container 34 in the front and rear direction. That is, in the second opening mode, it is preferable that the front storage zone 35 and the storage container 34 are drawn out forward to a position at which they are not overlapped in the up and down direction with the first door 10 and the second door 20 located above. Thereby, when taking out the storage container 34 in the second opening mode, the user can easily use the front storage zone 35 and the storage container 34 without interfering with the first door 10 or the second door 20 located above.

In order to further increase user's convenience, a portion of the rear storage zone 36 of the third door 30 may be drawn out forward in the second opening mode. However, even in this case, if the rear storage zone 36 is drawn out too much, cold air loss may occur in the rear region not used by the user, so it is preferable that the rear storage zone 36 is exposed to the outside by a distance that does not exceed the width of the front storage zone 35 in the front and rear direction.

As described above, according to the present invention, the opening mode of the door including the first opening mode in which the third door 30 is opened to the maximum and the second opening mode in which it is opened partially may be adjusted according to the user's selection. As described above, by selectively providing the function of opening the third door 30 only as much as the user needs, it is possible to minimize cold air loss and increase energy efficiency. Additionally, through the implementation of the second opening mode, by supporting the Quick Zone use mode for quickly taking out items, the user's convenience can be greatly increased.

Referring to FIG. 8, the controller 80 in the refrigerator 1 may receive input signals from the first input part 13, the second input part 51, and the third input part 52. Additionally, the controller 80 may receive sensing signals from the first sensor part 12 and the distance sensing sensor 120. In this way, the controller 80 receiving the input signals and the sensing signals may apply an operation signal to the door withdrawal module 43 to control the operation of the door withdrawal module 43. Additionally, the controller 80 may receive an impact signal, a stop signal, or the like from the door withdrawal module 43 to control the operation of the door withdrawal module 43.

[Distance Sensing Sensor Part]

Hereinafter, the distance sensing sensor part 100 according to an embodiment of the present invention will be described with further reference to FIGS. 9 to 13.

In the lower region of the third door 30, the distance sensing sensor part 100 may be disposed, which measures a separation distance from the sensing target 60. The distance sensing sensor part 100 may include one or more distance sensing sensors 120 performing a sensing function. Based on the separation distance from the sensing target 60 measured by the distance sensing sensor part 100, the controller 80 may control the operation of the door withdrawal module 43. As implied in the present specification, the separation distance from the sensing target 60 may mean a distance from the front surface of the third door 30 to the sensing target 60.

As implied in the present specification, the sensing target 60 may be a user. Generally, when the user intends to use the refrigerator 1, the user positions himself or herself to face the front surface of the refrigerator 1. In this way, when the user is positioned to face the front surface of the refrigerator 1, the foot 61 among the body parts of the user may be positioned closest to the refrigerator 1. That is, when the third door 30 is drawn out forward, the body part of the user that comes into contact with the front surface of the third door 30 first may be the user's foot 61. Therefore, according to the present invention, the distance sensing sensor part 100 is disposed in the lower region of the door to measure the separation distance from the sensing target 60, and thereby, the distance sensing sensor part 100 can sense the user's foot 61 to prevent the user's foot 61 from colliding with the door during the insertion or withdrawal movement of the door.

Further, since the distance sensing sensor part 100 is disposed in the lower region of the door to measure the separation distance from the sensing target 60, the distance sensing sensor part 100 can easily sense the user's foot 61 even if the sensing field of view FOV of the distance sensing sensor part 100 is not great. However, this is not exhaustive, and the distance sensing sensor part 100 may have a sensing field of view FOV allowing for sensing not only the user's foot 61 but also up to the user's ankle 62 and the user's legs 63.

As an example, the distance sensing sensor 120 included in the distance sensing sensor part 100 may be mounted on the third door 30 at such a height that it is overlapped with the user's foot 61 or the user's ankle 62 in the front and rear direction. For example, the distance sensing sensor 120 may be disposed to protrude downward from the lower surface of the third door 30 and to face forward. In this case, the distance sensing sensor 120 can sense the user's foot 61 or the user's ankle 62. However, the distance sensing sensor 120 may have little possibility of sensing the user's leg 63 due to an interference problem with the lower end of the front surface of the third door 30.

Because of this, as another example, the distance sensing sensor 120 may be disposed in a lower region of the front surface of the third door 30 to face forward. In this case, the distance sensing sensor 120 may sense not only the user's foot 61 and the user's ankle 62 but also up to the user's leg 63 without interference between the sensing field of view FOV and the third door 30. Thus, by adjusting the sensing field of view FOV in the up and down direction, the distance sensing sensor 120 can sense not only the user's foot 61 and the user's ankle 62, but also up to the user's leg 63.

In this case, the sensing field of view FOV of the distance sensing sensor part 100 may be set to have a greater sensing field of view in an upward direction than in a downward direction. It is preferable that the sensing field of view FOV of the distance sensing sensor part 100 in the downward direction is set so as not to contact the floor surface lest a sensing error occur because the floor surface is recognized. Therefore, it is preferable that the sensing field of view FOV of the distance sensing sensor part 100 in the downward direction is set at such a height as to be above the floor surface and recognize the top side of the general user's foot 61.

As implied in the present specification, examples of a user may include an infant as well as an adult. Since adults and infants have different body features such as stature, and adults also have different body features, it is important that the distance sensing sensor part 100 measures the separation distance from the user regardless of the user's body features. Thus, when the distance sensing sensor part 100 measures the user's foot 61, it may become possible to measure under the same condition based on the floor surface regardless of the user's body features. Besides, when the distance sensing sensor part 100 measures the user's foot 61, the separation distance can be sensed based on the foremost user's foot 61 without being affected by the number of users. In this way, by disposing, in the lower region of the door, the distance sensing sensor part 100 which measures the separation distance from the sensing target 60, the separation distance from the user can always be measured under the same condition without rendering the number of users and body features, such as stature, as variables.

Additionally, as implied in the present specification, the sensing target 60 is not limited to the user, and may refer to various obstacles that can be placed on the floor surface in front of the refrigerator 1, such as pets, robot vacuum cleaners, and various items. Although these sensing targets 60 may have different body heights depending on the kind, when the sensing target 60 has a low body height, it may not be sensed depending on the location and the sensing field of view of the distance sensing sensor part 100 unless the portion of the sensing target 60 in contact with the floor surface, such as the user's foot, is measured. Therefore, according to this invention, by disposing the distance sensing sensor part 100 in the lower region of the door to measure the separation distance from the sensing target 60, the distance sensing sensor part 100 can also sense the sensing target 60 which has a low height while in contact with the floor surface, thereby preventing the collision of the door with the sensing target 60 during the insertion or withdrawal movement of the door.

As described above, according to the present invention, by disposing the distance sensing sensor part in the lower region of the drawer-type door, it is possible to sense the obstacle that may occur near the floor surface, thereby preventing the collision thereof with the door. Besides, the distance sensing sensor part can have a sensing field of view allowing for sensing an obstacle in the lower end portion, such as a user's foot, a companion animal, or an infant, thereby minimizing the blind spot of the sensing.

Referring to FIG. 12, the distance sensing sensor part 100 may include one or more distance sensing sensors 120 and a body unit 110 storing the distance sensing sensor 120 therein. The body unit 110 may be formed to extend long in the left and right direction of the third door 30. For example, the body unit 110 may function as a finishing member capable of finishing the lower surface of the third door 30. Therefore, the body unit 110 may be formed to extend to a length substantially corresponding to the length of the third door 30 in the left and right direction so as to be able to finish the lower surface of the third door 30. The body unit 110 may be formed to have a plate shape as a whole.

At the rear portion of the body unit 110, a support part 113 may be formed to be bent upward. Since the support part 113 is formed to surround the corner portion connecting the lower surface and the rear surface of the third door 30, the fastening force between the distance sensing sensor part 100 and the third door 30 can be increased. The support part 113 may extend upward to a height that does not exceed a lower end of the gasket part 38 of the third door 30.

In front of the body unit 110, a handle part 112 may be formed. The handle part 112 may be formed to protrude upward with respect to the upper surface of the plate-shaped body unit 110, and may be formed in a shape recessed upward when viewed from its lower side. The handle part 112 may also be formed to extend long in the direction in which the body unit 110 extends. The handle part 112 may be formed to have a length shorter than that of the body unit 110, to which, however, the present invention is not limited. In the case where the body unit 110 is mounted on the lower end of the third door 30, the handle part 112 may be inserted inward and upward into the third door 30, so that the handle part 112 cannot be recognized from the front side of the third door 30. The user can insert his or her hand into the handle part 112 located at the lower end of the third door 30, and manually insert or withdraw the third door 30.

In the rear side of the body unit 110, a sensor accommodation part 111 may be formed, which accommodates one or more distance sensing sensors 120. In a state in which the distance sensing sensor part 100 is mounted on the third door 30, the sensor accommodation unit 111 may be disposed between the support part 113 and the handle part 112 based on the front and rear direction of the body unit 110. The sensor accommodation part 111 may be formed to protrude downward with respect to an upper surface of the body unit 110 having a plate shape, and may be formed in the form of being recessed downward when viewed from the upper side. The sensor accommodation part 111 may be formed to have a length shorter than that of the body unit 110, to which, however, the present invention is not limited.

In the case where the body unit 110 is mounted on the lower end of the third door 30, the sensor accommodation part 111 protrudes downward and outward from the third door 30, so that the sensor accommodation part 111 can be recognized from the front side of the third door 30. The handle part 112, which is located in front of the sensor accommodation part 111 to protrude upward, may be disposed so as not to be overlapped with the sensor accommodation part 111 in the front and rear direction. Thereby, the distance sensing sensor 120 stored in the sensor accommodation part 111 can sense the sensing target 60 without being subjected to interference with the handle part 112. Besides, since the handle part 112 is located in front of the sensor accommodation part 111 protruding downward, the user can insert his or her hand into the handle part 112 without interfering with the sensor accommodation part 111, and freely insert or withdraw the third door 30. The rear surface of the sensor accommodation part 111 may be formed to have an inclined surface. Thereby, it is possible to reduce collision between the rear surface of the sensor accommodation part 111 and an obstacle, that may occur when the third door 30 retracts.

However, this is not exhaustive, and the sensor accommodation part 111 may be located in a front portion of the lower surface of the third door 30. In this way, when the sensor accommodation part 111 is located in the front portion of the lower surface of the third door 30, the distance sensing sensor 120 accommodated in the sensor accommodation part 111 can have the abated interference of the sensing field of view FOV with the lower surface of the third door 30, thus further expanding the sensing distance of the distance sensing sensor 120. In this case, the handle part of the third door 30 may not be formed on the lower surface of the third door 30, but on the upper surface or the front surface of the third door 30, thereby solving the problem of interference with the sensor accommodation part 111.

The front side of the sensor accommodation part 111 may be open. In the sensor accommodation part 111, one or more distance sensing sensors 120 may be disposed. In the case where a plurality of distance sensing sensors 120 are provided, the plurality of distance sensing sensors 120 may be disposed to be spaced apart from each other by a predetermined distance in the left and right direction. In the case where the distance sensing sensor 120 is disposed in the lower region of the third door 30, the sensing distance may be shortened under consideration of the problem of interference with the floor surface, and, however, it is possible to minimize the blind spot of a sensor as much as possible by using a plurality of sensors.

The distance sensing sensor 120 may be a PSD sensor, to which, however, the present invention is not limited, and may be one of a TOF sensor, an ultrasonic sensor, a radar sensor, a lidar sensor, and a heat sensing sensor. The distance sensing sensor 120 may be disposed to face the front of the refrigerator 1. In the front side of the sensor accommodation part 111, a front cover part 130 may be disposed to finish the front side of the sensor accommodation part 111. In the front cover part 130, a hole part 131 may be formed to correspond to the distance sensing sensor 120. The distance sensing sensor 120 can sense the sensing target 60 located in the front of the refrigerator 1 through the hole part 131 formed in the front cover part 130.

In a case where a plurality of doors of the refrigerator 1 are provided, the distance sensing sensor part 100 may be formed at a lower portion of the door located at the lowermost portion. According to the present specification, three doors are included, and it has been described as an example that the distance sensing sensor part 100 is disposed at the lower portion of the third door 30, but in another embodiment, if the number of the doors is one or two, it may be disposed at the lower portion of the door located at the lowermost portion.

Since the distance sensing sensor part 100 described above is located in the rear side of the front surface of the third door 30, it is possible to protect the sensor from external shocks that may be caused by surrounding objects such as a vacuum cleaner and the like, and to improve the durability and reliability of the product.

Referring to FIG. 11, it is preferable that the distance sensing sensor part 100 protruding downward from the lower surface of the third door 30 is disposed to be spaced apart from the floor surface by a predetermined distance. For example, the lower surface of the cabinet 2 and the lower surface of the third door 30 may be positioned to be spaced apart by a predetermined distance from the floor surface by the height adjustment part 8 or the wheel part 9 supporting the lower surface of the cabinet 2. In this case, if the lowermost end of the distance sensing sensor part 100 protruding downward from the lower surface of the third door 30 protrudes to such an extent that it touches the floor surface, damage may occur when the third door 30 is sagged downward due to a large number of items stored in the third door 30. Therefore, in order to prevent the damage to the distance sensing sensor part 100 due to the sagging of the third door 30, it is preferable that the distance sensing sensor part 100 is disposed to be spaced apart by a predetermined distance from the floor surface. To this end, it is preferable that the height of the distance sensing sensor part 100 in the up and down direction, by which it protrudes downward from the lower surface of the third door 30, is set smaller than the height of the height adjustment unit 8 or the wheel unit 9 in the up and down direction.

[Control Method of an Opening Mode and a Closing Mode of a Door]

Hereinafter, with further reference to FIGS. 14 to 16, a control method of an opening mode and a closing mode of a door according to an embodiment of the present invention will be described. In the below description, the door will be based on the third door 30 having the distance sensing sensor part 100 disposed in the lower region.

Referring to FIG. 14, when a first opening mode step (S100) is started in which the door is automatically opened, the step (S110) of checking whether a door opening input signal of the first opening mode has been recognized may be performed. The door opening input signal may be a sensing signal sensed by the first sensor part 12 or an input signal input to the first input part 13. The first sensor part 12 and the first input part 13 may be a door opening signal input part. In the case where the door opening input signal is not recognized, the distance sensing sensor 120 is not activated, and the step of continuously checking whether the door opening input signal is input may be repeated.

In the case where the door opening input signal is input to the door opening signal input part, the step (S120) may be performed in which the distance sensing sensor 120 of the door is activated to measure the separation distance from the sensing target 60. As described above, according to the present invention, since the opening signal input part is provided intentionally by the user to open the door, when the door opening signal is input to the opening signal input part, the sensing function of the distance sensing sensor 120 may be activated. Through this, the user can control such that the door is opened only when the user wishes, thereby reducing unnecessary energy consumption and improving the user experience.

When the distance sensing sensor 120 starts to measure the distance from the sensing target 60 according to the step (S120), the step (S130) of checking whether the user's foot is measured to be within a safety distance may be performed. The safety distance may be a distance value preset in the controller 80. In other words, the safety distance is a buffer distance for beforehand preventing a collision with the sensing target 60 during the door insertion and withdrawal process, and its setting value can be changed.

For example, in the case where the separation distance from the sensing target 60 measured by the distance sensing sensor 120 falls within the safety distance, the control may be performed such that the door is not opened to prevent a collision with the sensing target 60 that may occur during the process of withdrawing the door forward. On the other hand, in the case where the separation distance from the sensing target 60 measured by the distance sensing sensor 120 does not fall within the safety distance, that is, in the case where the separation distance to the sensing target 60 exceeds the safety distance, the step (S140) may be performed, in which the door is opened to a preset first distance. The first opening mode may be set such that the door is fully opened, in which case the first distance means the maximum withdrawal distance of the door to which the door can be fully opened. As described above, according to the present invention, in the case where the separation distance from the sensing target 60 exceeds the preset safety distance, the control can be performed such that the door is opened automatically, which thus enables the door to be opened automatically while maintaining a safety distance from surrounding objects when the user uses the door, thereby providing both convenience and safety.

To perform the step (S140), the controller 80 may operate the automatic door opening and closing module 43 to withdraw the door forward. In this regard, even while the step (S140) is performed to open the door, the distance sensing sensor 120 may continuously measure the distance from the sensing target 60. Thus, according to the present invention, while the door is being opened, the distance sensing sensor 120 can continuously measure the separation distance to enable a quick reaction even if a new obstacle is sensed during the door opening and closing process, thereby preventing unexpected collisions and maximizing safety during use.

In the process of proceeding with the step (S140), when there is the step (S150) in which a special situation occurs, the controller 80 may perform the step (S160) of stopping the opening of the door in the first opening mode by stopping the driving of the driving part 46 of the automatic door opening and closing module 43.

For example, in the step (S150), when the separation distance from the sensing target 60 is measured to be less than or equal to a preset safety distance, the movement of the door may be stopped. In this case, when the sensed sensing target 60 is removed, the control may be performed such that the distance sensing sensor 120 confirms that the sensing target 60 has been removed from within the safety distance and the door is reopened to the first distance from the position where the movement is stopped.

Also, in the step (S150), when the driving time of the driving unit 46 of the automatic door opening and closing module 43 exceeds a preset door maximum opening reaching time, the movement of the door may be stopped. The time taken for the driving unit 46 to be driven until the first opening mode is activated may be calculated in advance, and the distance by which the door can be moved according to the driving time of the driving unit 46 may be set in advance. Therefore, in the case where the driving time of the driving unit 46 exceeds the maximum driving time of the driving unit 46 for the implementation of the first opening mode, which has been calculated in advance, it may be recognized that the door already exceeds the maximum set distance to which the door can be withdrawn, or that a problem occurs in the withdrawal operation process, so that additional withdrawal of the door can be stopped.

Also, in the case where the door reaches the maximum opening distance of the door in the step (S150), the movement of the door can be stopped. For example, on the side surface of the door or the side surface of the third storage chamber 7, a door full opening limit switch may be disposed, which can measure the state in which the door is fully opened. In an example, the door full opening limit switch may be provided as a sensor, and it can be ascertained whether the door has been withdrawn to the maximum opening distance based on the operation of the door full opening limit switch.

Additionally, in the case where it is recognized in the step (S150) that there is an impact in the driving unit 46 of the automatic door opening and closing module 43, the movement of the door may be stopped. For example, when the user's body collides with the door or other obstacles collide with the door, an impact may also be recognized in the driving unit 46 of the door withdrawal module 43. In this case, the setting may be made such that the movement of the door can be stopped when the impact applied to the driving unit 46 exceeds a preset period of time.

Referring to FIG. 15, when a second opening mode step (S200) is started in which the door is automatically opened, the step (S210) of checking whether a door opening input signal of the second opening mode has been recognized may be performed. The door opening input signal may be a sensing signal sensed by the first sensor part 12 or an input signal input to the first input part 13. The first sensor part 12 and the first input part 13 may be a door opening signal input part. In the case where the door opening input signal is not recognized, the distance sensing sensor 120 is not activated, and the step of continuously checking whether the door opening input signal is input may be repeated.

In the case where the door opening input signal is input to the door opening signal input part, the step (S220) may be performed in which the distance sensing sensor 120 of the door is activated to measure the separation distance from the sensing target 60.

When the distance sensing sensor 120 starts to measure the distance from the sensing target 60 according to the step (S220), the step (S230) of checking whether the user's foot is measured to be within a safety distance may be performed. The safety distance may be a distance value preset in the controller 80. In other words, the safety distance is a buffer distance for beforehand preventing a collision with the sensing target 60 during the door insertion and withdrawal process, and its setting value can be changed.

For example, in the case where the separation distance from the sensing target 60 measured by the distance sensing sensor 120 falls within the safety distance, the control may be performed such that the door is not opened to prevent a collision with the sensing target 60 that may occur during the process of withdrawing the door forward. On the other hand, in the case where the separation distance from the sensing target 60 measured by the distance sensing sensor 120 does not fall within the safety distance, that is, in the case where the separation distance to the sensing target 60 exceeds the safety distance, the step (S240) may be performed, in which the door is opened to a preset second distance. In the case of the second opening mode, it may be set as a mode in which the door is opened partially, and in this case, the second distance means a preset partial withdrawal setting distance of the door.

To perform the step (S240), the controller 80 may operate the automatic door opening and closing module 43 to withdraw the door forward. In this regard, even while the step (S240) is performed to open the door, the distance sensing sensor 120 may continuously measure the distance from the sensing target 60.

In the process of proceeding with the step (S240), when there is the step (S250) in which a special situation occurs, the controller 80 may perform the step (S260) of stopping the opening of the door in the second opening mode by stopping the driving of the driving part 46 of the automatic door opening and closing module 43.

For example, in the step (S250), when the separation distance from the sensing target 60 is measured to be less than or equal to a preset safety distance, the movement of the door may be stopped. In this case, when the sensed sensing target 60 is removed, the control may be performed such that the distance sensing sensor 120 confirms that the sensing target 60 has been removed from within the safety distance and the door is reopened to the second distance from the position where the movement is stopped.

Also, in the step (S250), when the driving time of the driving unit 46 of the automatic door opening and closing module 43 exceeds a preset door partial opening reaching time, the movement of the door may be stopped. The time taken for the driving unit 46 to be driven until the second opening mode is activated may be calculated in advance, and the distance by which the door can be moved according to the driving time of the driving unit 46 may be set in advance. Therefore, in the case where the driving time of the driving unit 46 exceeds the maximum driving time of the driving unit 46 for the implementation of the second opening mode, which has been calculated in advance, it may be recognized that the door already exceeds the maximum set distance to which the door can be withdrawn, or that a problem occurs in the withdrawal operation process, so that additional withdrawal of the door can be stopped.

Additionally, in the case where it is recognized in the step (S250) that there is an impact in the driving unit 46 of the automatic door opening and closing module 43, the movement of the door may be stopped. For example, when the user's body collides with the door or other obstacles collide with the door, an impact may also be recognized in the driving unit 46 of the door withdrawal module 43. In this case, the setting may be made such that the movement of the door can be stopped when the impact applied to the driving unit 46 exceeds a preset period of time.

As described above, according to the present invention, if the distance sensing sensor 120 recognizes an object during the opening of the door in the first or second opening mode, the control can be performed such that the door can be automatically stopped, thereby preventing unexpected collisions that may occur in the process of the opening and closing of the door, ensuring user safety, and preventing damage due to an overload of the automatic door opening and closing module 43 and damage to the door.

Referring to FIG. 16, a door closing mode step S300 may be started, in which the door is automatically closed. In this case, the closing mode of the door may be started when the driving of the driving unit 46 of the automatic door opening and closing module 43 is stopped and the movement of the door is stopped, such as when the door is fully opened like the first opening mode, or when the door is opened in part like the second opening mode. Additionally, the closing mode may be started in the state where the movement of the door is stopped, before it is opened to the first distance or the second distance set in the first or second opening mode, respectively, by the door opening mode stopping step (S150, S250) that may occur while the door is opened in the first or second opening mode.

When the door closing mode (S300) is started, in which the door is automatically closed, the step (S310) of checking whether a door closing input signal is recognized may be performed. The door closing input signal may be an input signal input to the first input part 13 or an input signal input to the second input part 51. The first input part 13 and the second input part 51 may be a door closing signal input part. In the case where the door closing input signal is not recognized, the control is not performed such that the door is closed, and the step of continuously checking whether the door closing input signal is input may be repeated.

When the door closing input signal is input to the door closing signal input part, the step (S320) of checking whether a door hold signal has been sensed may be performed. The door hold input signal may be an input signal input to the first input part 13 or an input signal input to the third input part 52. The first input part 13 and the third input part 52 may be a door hold signal input part. In the case where the door hold signal is input (S330), the movement of the door may be stopped for a preset period of time. Further, in the case where the door hold signal is input (S330), the movement of the door may be maintained stopped until the door hold signal is input again. In this case, the step (S340) of checking whether the door hold signal has been sensed again may be performed, and after the step (S340), a door automatic closing step (S350) may be performed, in which the door is automatically closed.

In this regard, if an impact is detected on the driving unit 46 of the door insertion and withdraw module 43 (S360) in the process of proceeding with the door automatic closing step (S350), the door closing operation may be stopped and changed to the opening mode (S370). For example, when the user's body collides with the door or other obstacles collide with the door, an impact may also be recognized in the driving unit 46 of the door withdrawal module 43. In this case, the setting may be made such that the closing operation of the door can be stopped when the impact applied to the driving unit 46 exceeds a preset period of time. Additionally, also in the case where the user holds a door handle part in the process of closing the door, the closing mode of the door can be changed to the opening mode. In this case, the opening mode changed from the closing mode may be the first opening mode or the second opening mode, or may be a third opening mode that is set in advance different from the first opening mode and the second opening mode.

As described above, according to the present invention, when an abnormal impact is detected while the door is closed, the controller can control such that the operation of the door is stopped or changed to the opening mode, thereby preventing additional damage.

Additionally, according to the present invention, the opening mode and the closing mode of the door may be set as desired by the user through a user-customized control function. Accordingly, in the automatic door closing step, when an impact is detected on the door, it can be changed to the opening step to ensure user safety, allowing the user to easily control the closing mode of the door. Through this, it is possible to react quickly even when the user closes the door by mistake or an object is unintentionally caught, thereby preventing the damage.

Additionally, according to the invention, the electric current change in the driving unit of the automatic door opening and closing module can be continuously monitored, so that, when an abnormal load or impact is sensed, it is possible to immediately stop or reverse the operation of the door, thereby enhancing the safety of users and products.

Additionally, according to the invention, there is provided the hold function of temporarily stopping the movement of the door according to the user's intention, and thus the user can set the door to be stopped as much as he/she wants when opening or closing the door, so that the door can be fixed at a desired location while taking out or organizing specific items. This can greatly improve user's convenience, and minimize inconvenience which may be caused when handling the door.

Although the present invention has been described with reference to the illustrative drawings as the above, the present invention is not limited to the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by those skilled in the art without departing from the scope of the technical idea of the present invention. Additionally, even if the effects related to the configuration of the present invention were not explicitly described while explaining the embodiments of the present invention, it is obvious that the effects predictable from the configuration should also be acknowledged.