Method and Apparatus for Aligning Laser to Optical System

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of PPA Ser. No. 61/841,615, filed 2013 Jul. 1 by the present inventors, which is incorporated by reference.

BACKGROUND

1. Discussion of Prior Art

This application relates to aligning a physically separate laser to a direct-view optical system for use on distant targets

2. Prior Art

Modern lasers and laser rangefinders are used by long range shooters to illuminate a target and measure the distance to a target, respectively. These devices include several lasers, including a visible one that the shooter can use to align the laser rangefinder to an optical device that is used to see the target. One challenge in using the visible laser to align the device to the direct-view optical system is that the laser is difficult to see in full daylight. The brightness of the sun overwhelms the eye's ability to see the laser, even with an optical system. Currently, users desiring to align their laser system to their optical system have to perform the alignment at short distances or during periods of low ambient illumination (before dawn or after dusk) so that they can see the laser spot. These short distances are much less than the distances that some users shoot targets at, which could be over 1000 meters. Aligning the systems at short distances introduces parallax into the alignment, making it difficult for the user to properly lase a long distance target. If misaligned, the laser rangefinder will suffer a decrease in performance, most likely returning the incorrect range to target.

The alignment target in U.S. Pat. No. 6,815,838 to Daubenspeck on 2002 Feb. 20 is appropriate for use with semiconductor devices, but not in an outdoor setting or at long distances. The method described in U.S. Pat. No. 6,793,494 to Varshneya on 2002 May 20 details a means for aligning a small arms transmitter, but fails to address how to see the laser at long distances. The U.S. Pat. No. 5,410,815 to Parikh on 1994 Apr. 29 describes a system to align a weapon mounted laser with the weapon's boresight, but it is a complex optomechanical system, and unsuitable for field work. It is also tailored specifically for a particular laser system in a training environment.

Forrest describes an apparatus for boresighting a firearm in U.S. Pat. No. 4,530,162 on 1983 Aug. 8 that shines a collimated light source through the barrel, which is acceptable for aligning a rifle scope, but provides no means to align a laser to the scope. The U.S. Pat. No. 5,001,836 to Cameron on 1990 Feb. 5 describes a means similar to U.S. Pat. No. 4,530,162, using a barrel-mounted laser to align a rifle scope, but does not address how to align a laser for long distances.

ADVANTAGES

One advantage of one or more aspects is to allow the user to more easily see the laser spot in various ambient lighting conditions, especially at longer distances. Another advantage is that alignment target may reduce the time it takes for a shooter to align the laser to a telescopic scope. Another advantage is that the target will allow the user to more precisely align the laser system to the optical system. Other advantages include ease of use, low complexity, and low cost. These and other advantages will become apparent from a consideration of the ensuing description and accompanying drawings.

DRAWINGS—FIGURES

FIG. 1 shows various aspects of a target supplied with a reflective material and support backing in accordance with one embodiment.

FIG. 2 shows example of weapon-mounted laser system emitting a laser that is reflected by one embodiment of a target

FIG. 3 shows a flowchart of method for aligning weapon-mounted laser system with one embodiment of a target

FIG. 4 shows an illustration of the steps in FIG. 3

FIGS. 5A and 5B shows various aspects of a target supplied with flexible materials in accordance with another embodiment.

DRAWINGS—REFERENCE NUMERALS

DETAILED DESCRIPTION—FIRST EMBODIMENT—FIG. 1

One embodiment of the target 20 is illustrated in FIG. 1. The target 20 consists of a reflective material 26 attached to a support structure 28. The reflective material 26 may consist of a plurality of retroreflectors 30 that reflect incoming light 18 back in the direction from which it entered the retro reflector 30.

In one embodiment, the reflective material 26 is an adhesive sheet, such as 3M reflective sheeting for traffic signs, which is attached to a support structure 28. The reflective material 26 can come in other forms, such as transfer films, fabrics, pressure-sensitive adhesive films, etc. In one embodiment, the support structure 28 is aluminum; however, the support structure 28 can consist of any material that protects the reflective material 26 from normal wear, such as nylon fabric or plastic sheets.

OPERATION—FIRST EMBODIMENT—FIGS. 2-4

FIG. 2 shows the basic configuration of one embodiment. The method or arrangement of mounting the optical system 14 and laser system 12 upon the weapon 16 will be well known to those with ordinary skill in the mechanical and shooting arts. The method of adjusting the laser system's 12 alignment will be well known to those with ordinary skill in the shooting arts.

FIG. 3 shows a flowchart of how to align the laser system 12 with the optical system 14 using one embodiment of the target 20. The target 20 is affixed at a short distance, with its reflective surface pointed back at the laser system. The laser system 12, mounted on the weapon 16 along with the optical system 14, is configured to emit its light 18. The weapon 16, with attached laser system 12 and optical system 14 is scanned back and forth near the target until the reflected light 22 is visible through the optical system 14 on the target 20. The offset from the optical system's markings 24 is noted, and the adjustment mechanism of the laser system 12 is used to move the reflected light 22 on the target 20 until the reflected light 22 is located in the center of the optical system's 14 field of view. This results in a coarse alignment of the laser system and optical system.

The target 20 is then moved to the desired shooting range or maximum effective range of the weapon and affixed there. The process of activating the light source 18, scanning the optical system 14 near the target 20, and adjusting the laser system 12 is repeated at this longer range to refine the alignment between optical system 14 and laser system 12.

FIG. 4 shows an illustration of what will be seen through the optical system 14 while performing the process described in FIG. 3.

DESCRIPTION—ALTERNATIVE EMBODIMENT—FIGS. 5A and B

FIG. 5A shows an additional embodiment of target 20 that uses a fabric reflective material 26 and nylon fabric support structure 28. This embodiment includes a cross marking 40 on the reflective material 26 to assist with alignment, however, the marking could consist of different shapes, such as a box, dot, circle, etc. This embodiment also includes a flexible string 36 attached to the support structure 28 so that the target 20 can be hung from various available structures. Additionally, this embodiment may include a weight 40 sewn into the support structure 28 that helps prevent the target 20 from moving when used outdoors.

FIG. 5B shows how the embodiment can be rolled up around the weight 40 so that the target 20 can be stowed in a bag, backpack, or pocket.

CONCLUSION, RAMIFICATIONS, AND SCOPE

Accordingly, the reader will see that at least one embodiment of the target provides a low cost, lightweight, reliable apparatus that can be used by persons of almost any skill level to align a laser system to an optical system. From the description above, a number of advantages of some embodiments of our alignment apparatus and method become evident:

• • 1. The use of reflective material will permit a user to see a laser at much further distances, which increases the accuracy of the alignment between a laser system and an optical system, as well as decreasing the time required to align the two.
  • 2. The use of reflective material will permit a user to align the two systems outdoors during the day.
  • 3. The use of flexible materials will permit a user to carry an embodiment with him for alignment in the field.
  • 4. The use of markings on the reflective material will permit a user to easily see the target and align the optical system upon it.

While our above description contains many specificities, these should not be construed as limitations on the scope, but rather as an exemplification of several embodiments thereof. Many other variations are possible:

• • The support structure 28 may be either flexible or rigid.
  • The support structure 28 may be eliminated if the target 20 is to be affixed to a permanent structure.
  • The target 20 may be shaped in other forms, such as circular or man-shaped.
  • The size of the target 20 may be changed, such as increasing its size for alignment at long ranges, or made smaller for portability
  • The reflective material 26 may be of different form, such as a flexible fabric or an adhesive sheet.
  • The target 20 may have different mechanisms for hanging it at range, such as magnets for attaching to a metal surface, or a flexible wire, or rope for hanging on a nail.
  • The reflective material 26 and support structure 28 may be of a different color.
  • The reflective material 26 may have markings on it that could allow a user to align the system more quickly, such as a grid pattern, a dot, or similar.
  • The target 20 may have weights in it to help stabilize it in high winds.
  • The target 20 may have a mechanism for supporting a flexible embodiment, causing it to pop out when deployed.
  • The reflective 30 may have a different design, such as spherical or corner.
  • The target 20 could take the form of a single retroreflector, such as a corner cube.

Thus, the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.