Single multiple aperture (“smart”) lens system
One version of the invention relates to a laser detection system that includes a ball lens and a plurality of fiber optic bundles placed adjacent the ball lens so that incoming light rays are focused onto the bundles by the ball lens. In one particular version of the invention, a ball lens is one that can provide an almost infinite number of “principal” axes for off-axis light. Each fiber optic bundle is aimed in a different direction from each other bundle so that each bundle will have a different FOV even though the same ball lens is used to focus the incoming light rays.
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This invention relates generally to optical systems and, more particularly, to optical devices for determining the position of a source of light incident on the device.
BACKGROUND OF THE INVENTIONOptical systems for determining the geographical position of a source of light are used in a variety of applications. For example, conventional laser-guided missiles make use of reflected light from a laser beam pointed toward a potential target. Once a target is selected, information from the laser beam is used to determine the position of the target relative to the missile.
Such laser-guided missile systems are known in the art. One exemplary system is described in U.S. Pat. 5,784,156, to Nicholson, incorporated herein by reference. The incoming reflected light is detected at apertures located at different points on the exterior of the missile, typically on the nose cone or wing edges. Each aperture is provided with a lens or lens system that focuses the incoming light onto a bundle of fiber optic cables running inside the missile. The fiber bundles then transmit the incoming light onto sensors that convert the incoming light into electrical signals. These electrical signals are then analyzed by computers on board the missile to determine the relative distance, azimuth, and elevation between the missile and the object from which the incoming laser light is reflected.
Each aperture and its corresponding fiber bundle, or bundles, possesses a field-of-view (“FOV”), i.e., an angle from which it can detect light. All of the individual FOV of the apertures together form the overall FOV of the missile. Since the FOV of a given aperture is limited by the optics involved, to increase the FOV of a missile, one must typically increase the number of apertures and lenses employed by the missile. This problem is illustrated in FIG. 1B.
Similarly, another optical laser-guided missile system currently in use employs a plurality of ball lenses at each aperture, with each ball lens associated with a single fiber bundle. This arrangement is shown in
In one embodiment, the laser detection system comprises a ball lens and a plurality of fiber optic bundles placed adjacent the ball lens so that incoming light rays are focused onto the bundles by the ball lens. In one version of the invention, a ball lens is one that can provide, an almost infinite number of “principal” axes for off-axis light. Each fiber optic bundle is aimed in a different direction from each other bundle so that each bundle will have a different FOV even though the same ball lens is used to focus the incoming light rays. Because the fields-of-view of all the bundles together form the overall FOV of the ball lens, the more bundles that are incorporated into the system, the larger the FOV of a given ball lens. In one advantageous embodiment, the bundles may be disposed so that their fields-of-view may overlap partially.
Referring now to
According to a further embodiment to the invention, the advantages obtained by the optical system shown in
Of course, it is not required that all the field-of-views overlap, and in other embodiments in the invention, the field of views can be non-overlapping, as a matter of design choice. In order to receive signals that can be used for guidance, at least adjacent fiber directions should produce an overlapping field-of-view. The fact that all FOVs do not overlap may be advantageous to systems that combine signals to a single detector. The non-overlapping FOVs in this case would produce less background noise due to a reduced field-of-view.
Of course, the above embodiments have been described with respect to two dimensional drawings showing differences in the elevation of the field-of-views for the fiber bundles; however, those who are skilled in the art will recognize that it will be useful to arrange fiber bundles to increase the total FOV of the system in azimuth as well as elevational dimensions.
In another embodiment of the invention, it is useful if the ball lenses are manufactured from different types of materials or glass. This allows one to modify the field-of-view of the lens and to affect the amount of coupling of light to the adjacent fiber bundles. One also has the flexibility to use different sizes of ball lenses. This also affects the overall FOV when used in conjunction with fiber bundles of different diameters and different numerical apertures (“NA”).
In still a further embodiment to the invention, it is possible to substitute a drum lens in place of the ball lens shown in
In still a further embodiment to the invention, it is useful that the effective FOV of the lens/fiber system be varied as follows. All fiber bundles point toward the center of the ball lens. The field-of-view is changed by varying the angle of each fiber bundle relative to the central or principal axis. The amount of overlapping signal depends upon the size of the fiber bundle at a particular angle. By pushing the fiber bundles closer to the ball lens, the amount of overlap between adjacent fiber bundles increases. The FOV can also be changed by varying the NA of each fiber. Therefore, the overall FOV can be controlled by changing the ball lens diameter or material composition, by changing the fiber numerical aperture, by changing the fiber bundle size, and/or by changing the fiber displacement from the ball lens. All of these factors are related to the required guidance precision.
There are many ways information from the reflected light energy may be used to determine the direction to the target. In one embodiment of the invention, each fiber bundle is coupled to a detector that converts the reflected light into electrical signals. The amplitudes of these electrical signals are related to the amount of light energy received from its corresponding fiber bundle. Because each fiber bundle has a unique FOV, those of skill in the art will recognize that the amount of energy received at the various FOVs can be interpolated to calculate the direction to the target.
Although the present invention has been described with respect to its application in guided missile systems, those who are skilled in the art will recognize that the invention also pertains to increased field-of-views in optical systems employing fiber optic cables in connection with optical lenses. For example, the invention is easily adapted to any system that uses reflected laser energy for guidance. For example, any robotic system could use reflected laser light in conjunction with the ball lens for increased precision in navigating toward the target. This could include mobile robots, such as cars, androids, etc. that have a task to move from point A (their present location) to point B where the item of interest is located. Similarly, a robotic arm could be guided to a laser illuminated “part of interest” located on a moving platform, such as a conveyor belt. Still other applications within the scope and spirit of the present invention will occur to those of skill in the art in view of the foregoing disclosure.
Claims
1. A laser detection system comprising:
- at least one ball lens formed of a solid single element;
- a plurality of fiber optic bundles disposed adjacent the ball lens, at least some of the plurality of fiber optic bundles being pointed toward a center of the ball lens and adapted to have overlapping fields-of-view with other fiber optic bundles;
- a laser adapted to direct a beam of light toward a target, such that the ball lens is arranged on a vehicle to receive reflected light from the target; and
- a computer system that processes information related to the reflected light to guide the movement of the vehicle relative to the target.
2. The laser detection system of claim 1 wherein the computer system guides the movement of the vehicle relative to the target based on an interpolation between differences in the reflected light from different fiber optic bundles.
3. The laser detection system of claim 2 further comprising a plurality of detectors for converting reflected light into electrical signals, wherein the computer system uses the electrical signals to compare an amount of energy contained in the light from the plurality of fiber optic bundles and uses this comparison to calculate the direction of the vehicle to the target.
4. The laser detection system of claim 1 further comprising a sensor system having a plurality of detectors coupled to the fiber optic bundles.
5. The laser detection system of claim 1 wherein the plurality of fiber optic bundles comprise multiple fiber optic bundles.
6. The laser detection system of claim 5 wherein multiple fiber optic bundles are disposed to form an array around a bundle in the center of the array.
7. An apparatus for use in guided vehicle applications, the apparatus comprising:
- a laser for directing a beam of light toward a target;
- a ball lens formed of a solid single element and arranged on the vehicle to receive reflected light from the target;
- a plurality of fiber optic bundles coupled to the ball lens, at least some of the plurality of the fiber optic bundles being pointed toward a center of the ball lens and adapted to have overlapping fields-of-view with other fiber optic bundles, wherein the fiber optic bundles pass the reflected light; and
- a computer system that receives information related to the reflected light passed from the fiber optic bundles and processes the information to guide the movement of the vehicle relative to the target.
8. An apparatus as in claim 7 further comprising a plurality of detectors for converting light into electrical signals.
9. An apparatus as in claim 8 wherein the electrical signals generated by each detector is are responsive to the amount of energy contained in the light received from its corresponding fiber optic bundle.
10. An apparatus as in claim 9 wherein the computer system uses the electrical signals to compare amount the amounts of energy contained in the light from the plurality of fiber optic bundles and uses this comparison to calculate the direction to the target.
11. A laser detection system, comprising:
- at least one drum lens formed of a solid single element;
- a plurality of fiber optic bundles disposed adjacent the drum lens, at least some of the plurality of fiber optic bundles being pointed toward a center of the drum lens and adapted to have overlapping fields-of-view with other fiber optic bundles;
- a laser adapted to direct a beam of light toward a target, such that the drum lens is arranged on a vehicle to receive reflected light from the target; and
- a computer system that processes information related to the reflected light to guide the movement of the vehicle relative to the target.
12. The laser detection system of claim 11 wherein the computer system guides the movement of the vehicle relative to the target based on an interpolation between differences in the reflected light from different fiber optic bundles.
13. The laser detection system of claim 12 further comprising a plurality of detectors for converting reflected light into electrical signals, wherein the computer system uses the electrical signals to compare an amount of energy contained in the light from the plurality of fiber optic bundles and uses this comparison to calculate the direction of the vehicle to the target.
14. The laser detection system of claim 11 further comprising a sensor system having a plurality of detectors coupled to the fiber optic bundles.
15. The laser detection system of claim 11 wherein the plurality of fiber optic bundles comprise multiple fiber optic bundles.
16. The laser detection system of claim 15 wherein multiple fiber optic bundles are disposed to form an array around a bundle in the center of the array.
17. An apparatus for use in guided vehicle applications, the apparatus comprising:
- a laser for directing a beam of light toward a target;
- a drum lens formed of a solid single element and arranged on the vehicle to receive reflected light from the target;
- a plurality of fiber optic bundles coupled to the drum lens, at least some of the plurality of the fiber optic bundles being pointed toward a center of the drum lens and adapted to have overlapping fields-of-view with other fiber optic bundles, wherein the fiber optic bundles pass the reflected light; and
- a computer system that receives information related to the reflected light passed from the fiber optic bundles and processes the information to guide the movement of the vehicle relative to the target.
18. An apparatus as in claim 17 further comprising a plurality of detectors for converting light into electrical signals.
19. An apparatus as in claim 18 wherein the electrical signals generated by each detector are responsive to the amount of energy contained in the light received from its corresponding fiber optic bundle.
20. An apparatus as in claim 19 wherein the computer system uses the electrical signals to compare the amounts of energy contained in the light from the plurality of fiber optic bundles and uses this comparison to calculate the direction to the target.
4106726 | August 15, 1978 | Emmons et al. |
4131248 | December 26, 1978 | Berglund |
4395121 | July 26, 1983 | Nory et al. |
4598884 | July 8, 1986 | Speer |
4634230 | January 6, 1987 | Spezio |
4675532 | June 23, 1987 | Carson |
4696441 | September 29, 1987 | Jones et al. |
4792675 | December 20, 1988 | Laughlin |
4825063 | April 25, 1989 | Halldorsson et al. |
4835381 | May 30, 1989 | Sorensen, III |
4914284 | April 3, 1990 | Halldorsson et al. |
4923276 | May 8, 1990 | Wells |
4952042 | August 28, 1990 | Pinson |
4965453 | October 23, 1990 | Hoschette et al. |
5014621 | May 14, 1991 | Fox et al. |
5047776 | September 10, 1991 | Baller |
5052635 | October 1, 1991 | Paulet et al. |
5056914 | October 15, 1991 | Kollodge |
5082201 | January 21, 1992 | Le Bars et al. |
5114227 | May 19, 1992 | Cleveland, Jr. |
5129595 | July 14, 1992 | Thiede et al. |
5181263 | January 19, 1993 | Derfiny |
5191385 | March 2, 1993 | Kasser |
5202742 | April 13, 1993 | Frank et al. |
5206499 | April 27, 1993 | Mantravadi et al. |
5275354 | January 4, 1994 | Minor et al. |
5311611 | May 10, 1994 | Migliaccio |
5319968 | June 14, 1994 | Billing-Ross et al. |
5319969 | June 14, 1994 | Billing-Ross et al. |
5323987 | June 28, 1994 | Pinson |
5345304 | September 6, 1994 | Allen |
5357331 | October 18, 1994 | Flockencier |
5477383 | December 19, 1995 | Jain |
5500520 | March 19, 1996 | Komine |
5528358 | June 18, 1996 | Bjorkman et al. |
5682225 | October 28, 1997 | DuBois et al. |
5760852 | June 2, 1998 | Wu et al. |
5771092 | June 23, 1998 | Dubois et al. |
5784156 | July 21, 1998 | Nicholson |
5788180 | August 4, 1998 | Sallee et al. |
6014270 | January 11, 2000 | Bergmann et al. |
6163372 | December 19, 2000 | Sallee et al. |
6349160 | February 19, 2002 | Tsien et al. |
2002090920 | March 2002 | JP |
Type: Grant
Filed: Jan 14, 2005
Date of Patent: Sep 28, 2010
Assignee: BAE Systems Information and Electronic Systems Integration Inc. (Nashua, NH)
Inventors: Les H. Richards (Round Rock, TX), James E. Nicholson (Austin, TX)
Primary Examiner: Isam Alsomiri
Attorney: Locke Lord Bissell & Liddell LLP
Application Number: 11/036,319
International Classification: G01B 11/26 (20060101); F41G 7/00 (20060101); G01C 21/02 (20060101); G01V 1/42 (20060101);