Abstract:
An optical system or assembly is formed of a plurality of optical sources ( 10, 12, 14 ) and components of different laser-based equipment systems. The sources and/or components may be combined and/or eliminated to reduce complexity, cost and/or overall weight of the system by consolidating multiple laser sources into a reduced number of sources, and by multiplexing ( 19 ) different wavelength signals over common carriers. A laser engagement system ( 12, 14 ) and an infrared aim light ( 10 ) (or infrared illuminator) are powered by a single laser source which is adopted for use with conventional equipment by lengthening the duration of the coded pulses emitted by the transmitter. The transmitter may be triggered in response to the heat and/or pressure generated by the blank upon firing. A visible bore light may be eliminated by connecting infrared and/or visible aim light ( 10 ) directly to a rifle barrel. The laser engagement system and the infrared aim light (or infrared illuminator) are provided in a common housing assembly ( 410 ).

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to optics and optical systems and devices. The present invention also relates to a method of operating a multi-function optical system. The present invention also relates to an assembly for a multi-function optical system.  
         BACKGROUND OF THE INVENTION  
         [0002]    Multi-function laser-based systems are employed for a variety of purposes. For example, it has been suggested to provide up to seven different laser-based equipment systems in combination, including the following: (1) a laser range finder; (2) an infrared aim light; (3) an infrared illuminator (a flashlight); (4) a visible aim light; (5) a visible bore light (a mandrel boresight laser for aligning sights); (6) a combat identification system; and (7) a multiple integrated laser engagement system for laser-tag simulated exercises, referred to herein as a “laser simulation system.” 
           [0003]    Prior art multi-function laser-based systems are generally complex and bulky. There is a need in the art for a system in which components are combined and/or eliminated to reduce complexity, cost and overall weight. In particular, there is a need for an optical system which provides multiple functions with a reduced number of optical sources and/or other components. Additionally, there is a need for an uncomplicated method of operating a multi-function optical system. Additionally, there is a need for an assembly for a multi-function optical system.  
         SUMMARY OF THE INVENTION  
         [0004]    The disadvantages of the prior art are overcome to a great extent by the present invention. Although the invention is illustrated in the drawings in connection with known functions, the invention is considered applicable to a number of other uses as well. In general, the invention may be applicable wherever complexity, cost and/or weight can be reduced by combining the functionality of optical sources and/or other components.  
           [0005]    According to one aspect of the invention, a plurality of optical sources and components of different laser-based equipment systems are combined and/or eliminated to reduce complexity, cost and/or overall weight. This aspect may be accomplished by consolidating multiple laser sources into a reduced number of sources, and by multiplexing different wavelength signals over common carriers, and there are other aspects of the invention.  
           [0006]    According to another aspect of the invention, a laser simulation system and an infrared aim light (or infrared illuminator) are powered by a single laser source. According to this aspect of the invention, a single laser source can be adopted for the laser simulation system by lengthening the duration of the coded pulses emitted by the laser simulation system transmitter. The shorter wavelength pulses are attenuated to a greater degree by the filter cap on the laser simulation system receiver. Thus, by lengthening the pulses, the laser simulation system receiver is actuated by the pulses in the same way as if they were conventional pulses. The laser simulation system receiver may optionally be located on the person who is being targeted.  
           [0007]    According to another aspect of the invention, the laser simulation system transmitter is triggered in response to the heat and/or pressure generated by blank ammunition gasses upon firing. This provides a way to ensure that the transmitter is only initiated when someone actually pulls the trigger on the laser simulation system.  
           [0008]    According to another aspect of the invention, the visible bore light (item (5) mentioned above) may be eliminated by connecting the infrared and/or visible aim light directly to the rifle barrel.  
           [0009]    According to another aspect of the invention, a multifunction lens system is provided which integrates multiple lenses for outputting several different functions. The lens system may be formed of first and second lenses fixedly connected to each other, or one formed on a portion of the other, with each lens providing various functional outputs. Optionally, the first lens can be a collimating lens.  
           [0010]    According to yet another aspect of the invention, a method of fabricating an optical system comprised of a plurality of optical sources and components of different laser-based equipment systems is provided. Laser sources operated at different wavelengths are wavelength division multiplexed (WDM) through various optical transmission lines to power six or more different functional outputs.  
           [0011]    The present invention also relates to an enclosure for enclosing an optical output device, laser sources and other optical and/or electrical components. The enclosure may be mounted on an aimable device, such as a rifle or binoculars.  
           [0012]    These and other advantages and features of the invention will become apparent from the following detailed description of the invention which is provided in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a schematic view of an optical system constructed in accordance with a preferred embodiment of the invention.  
         [0014]    [0014]FIG. 2 is a cross sectional view of a lens device constructed in accordance with a preferred embodiment of the invention.  
         [0015]    [0015]FIG. 3 is a partial schematic view of another optical system constructed in accordance with another preferred embodiment of the invention.  
         [0016]    [0016]FIG. 4 is an exploded view of an optical assembly constructed in accordance with one embodiment of the present invention.  
         [0017]    [0017]FIG. 5 is a cross sectional view of the optical assembly of FIG. 4.  
         [0018]    [0018]FIG. 6 is a cross sectional view of the optical assembly of FIG. 4.  
         [0019]    [0019]FIG. 7 is a cross sectional view of a sight block for the assembly of FIGS.  4 - 6 .  
         [0020]    [0020]FIG. 8 is a cross sectional view of another embodiment of a sight block according to the present invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0021]    Referring now to the drawings, where like reference numerals designate like elements, there is shown in FIG. 1 an optical system  1  constructed in accordance with a preferred embodiment of the invention. The illustrated system  1  has a first source  10  for generating a first input laser energy  5 . The first input energy  5  may have a wavelength in the near infrared spectrum (the infrared spectrum near the visible spectrum), for example from about 820 nanometers (nm) to about 860 nm, preferably about 825 nm.  
         [0022]    The first input energy  5  propagates through an optical transmission line  40  and is launched into an optical coupler or splitter  16 . The coupler  16  distributes optical power among two or more ports  17 ,  19 . The coupler  16  directs a first portion of the input energy  5  into transmission line  48  and a second portion of the input energy  5  into transmission line  46  (in direction  56 ). The split of the first portion and the second portion will depend upon the requirements of the system. For example, the split may be 60% to 40%, 80% to 20%, 100% to 0%, or other split. The input energy  5  propagating in transmission line  48  enters a lens  20  and is output from the lens  20  as an infrared illuminating light.  
         [0023]    The input energy  5  propagating through transmission line  46  enters a multiplexer  18 . The input energy  5  is transmitted through the multiplexer  18  and is launched into transmission line  50  (in direction  59 ) to enter a second lens  24 . Light energy  5  output from the second lens  24  may be used in a laser training simulation system. A conventional laser simulation system source operates at 904 nanometers. Thus, according to the illustrated embodiment, the 825 to 860 nanometers source  10  is adopted for the laser simulation system by lengthening the duration of the coded pulses  30 . The shorter wavelength pulses (825 nm to 860 nm, which are shorter than the conventional 904 nm) are attenuated to a greater degree by the filter cap (not shown) on the known laser simulation system receiver (not shown). Thus, the laser simulation system receiver is actuated by the 825 to 860 nm pulses in the same way as if they were 904 nm pulses. The laser simulation system receiver may be located on the person (not shown) who is targeted by the laser simulation system transmitter  24 .  
         [0024]    In a known laser simulation system, the user pulls a trigger to fire a blank cartridge to simulate the firing of an actual round and, in response, a sensor on the laser simulation system transmitter triggers the laser. The player identification and transmitter type can be encoded on the laser beam using a laser simulation system code. An electronic controller is connected through an amplifier to the optical detectors to decode the output signals thereof and provide an indication that the person carrying the receiver has been hit by the laser.  
         [0025]    It is possible, however, for a user to simulate the firing of a blank cartridge without actually firing a blank by manipulating the rifle to “re-coil” such that the laser simulation system transmitter is operated. Thus, the laser shot from that transmitter can go unrecognized, giving the user an unfair advantage. To overcome these problems, the present invention provides a laser simulation system transmitter  10 ,  24 ,  30  that is triggered in response to the heat and/or pressure generated by the blank ammunition gasses upon firing. This provides a way to ensure that the transmitter  10 ,  24 ,  30  is only initiated when the user actually pulls the trigger (not shown).  
         [0026]    Further, the optical system  1  has a second driver or source  12  for providing a second input energy  7 . The second input energy  7  may be laser light with a wavelength in the visible spectrum (e.g., about 630 nm to about 650 nm, preferably about 635 nm). The second input energy  7  propagates through optical transmission line  42  into the coupler  16 . The coupler  16  directs about 100% of the input energy  7  into transmission line  46  in direction  54 . The input energy  7  propagating through transmission line  46  enters the multiplexer  18 . The multiplexer  18  directs the input energy  7  into transmission line  50  in direction  59  to enter the second lens  24 . The input energy  7  output from the second lens  24  may be used as a visible aiming light  32 .  
         [0027]    In addition, a third driver or source  14  may be used to provide a third input energy  9  having a wavelength of about 1530 nm to about 1555 nm, preferably about 1538 nm. In a preferred embodiment, the third input energy  9  is amplified by an erbium-doped fiber amplifier  70  for further propagation in transmission line  44 .  
         [0028]    The third input energy  9  traveling along optical transmission line  44  enters circulator  62  which acts as a passive waveguide junction between the multiplexer  18  and a photodetector  64 . The third input energy  9  transmitted out of the circulator  62  in direction  65  enters the multiplexer  18 . The multiplexer  18  inputs the third input energy  9  into transmission line  50  in direction  59 . Thus, the input energy  9  exits the second lens  24  as fifth output light  34 , which may be used, for example as a combat identification transmission.  
         [0029]    Additionally, the input energy  9  exiting the lens  24  may form a light  36  for a laser rangefinder system. According to this aspect of the invention, the output light  36  is returned back to the lens  24  as returned light  38 , which may be used to determine target position, target coordinates and the like. The returned light  38  is propagated back through optical communication line  50  in direction  66  to the multiplexer  18  and from there through the circulator  62  and into a photodetector  64 . The photodetector  64  may be a processor-based system which can receive the returned light  38  and integrate and process the information contained therein.  
         [0030]    If desired, the optical system  1  also may be provided with a visible borelight assembly  3 . In the borelight assembly  3 , input energy  7  travels in direction  58  along optical transmission line  52 . The input energy  7  enters an additional lens  22  and exits as optional output light  29 . In an alternative embodiment of the invention, the entire borelight assembly  3  may be eliminated by connecting the first output light  26  (infrared aim light) and/or the fifth output light  34  (visible aim light) directly to the rifle barrel (not illustrated).  
         [0031]    [0031]FIG. 2 shows a lens device  2  constructed in accordance with a preferred embodiment of the invention. Lens device  2  comprises the first lens  20  and the second lens  24  fixedly connected to each other. The first input energy  5  enters the first lens  20  and exits as an output light  26 . As discussed above, the output light  26  may be used for infrared illumination.  
         [0032]    Additionally, first input energy  5  can enter second lens  24  and exit as third output light  30 , to be used in an otherwise conventional laser simulation system. The second input energy  7  enters second lens  24  and exits as fourth output light  32 . The fourth output light may be used as a visible aiming light. The third input energy  9  enters second lens  24  and exits as fifth output light  34  or sixth output light  36 . Preferably, the fifth output light  34  is used for combat identification transmission and the sixth output light  36  is used in a rangefinder system.  
         [0033]    Thus, the optical system  1  has multiple functions and integrates multiple lenses for outputting light beams for several different purposes. The lens system can optionally comprise a first lens and a second lens fixedly connected to each other, with each lens providing various functional outputs.  
         [0034]    Referring now to FIG. 3, there is shown an alternative optical power supply system in which the first input energy  5  propagates through an optical transmission line  40  and is launched into an optical splitter  200 . The splitter  200  distributes the signal  5  into two or more ports  202 ,  204 . 40% of the power  5  may be propagated into an optical transmission line  48 . 60% of the power is distributed into a second line  208 . The percentages of the power distributed through the two lines  48 ,  208  may be changed as desired. The signal  7  from the second source  12  is transmitted through optical line  42  and is coupled with the power in the line  208  by a coupler  206 . The coupler  206  outputs a desired portion of the two signals  5 ,  7  into an output line  46 . The output line  46  is connected to the multiplexer  18  as discussed above.  
         [0035]    [0035]FIG. 4 shows a multi-laser apparatus  410  constructed in accordance with another preferred embodiment of the invention. The illustrated apparatus  410  has a cover  412 , a body  420 , a hood  414 , and a sight block  440 . The block  440  is located on a rifle barrel  470  as described in more detail below. The rifle barrel  470  is shown in FIG. 6. The body  420  is mounted on the rail  444  of the sight block  440  by suitable fasteners. The hood  414  is mounted on the forward end of the body  420  by bolts  413  or the like. The cover  412  is removably located on top of the body  420  to enclose various electronic and optical components as discussed in more detail below.  
         [0036]    The sight block  440  has first and second clamps  441 ,  442  that are mounted around the rifle barrel  470 . Insulating layers or devices may be located within the clamps  441 ,  442  to protect the components within the body  420  from high temperatures generated within the rifle, if desired. The present invention should not be limited, however, to the preferred embodiments shown and described in detail herein. A block rail  444  is integrally connected to the clamps  441 ,  442 . The body  420  is supported on the block rail  444 . The term “sight block” takes its name herein from its position on the rifle where a rifle sight is otherwise conventionally located. If desired, one or more gun sights  430 ,  431  may be located on the top of the body  420 , as described in more detail below. The sight block  440  may also have a middle portion  443  integrally connected to the clamps  441 ,  442  to provide a single unitary device. A front portion or hood  445  is located at the front part of the sight block  440 . The middle portion  443  and the hood  445  may have curved inner surfaces (hidden from view in FIG. 4) to conform to the upper surface of the rifle barrel  470 .  
         [0037]    The insulating layers  472  on the inside of the clamps  441 ,  442  are shown in FIG. 7. The insulation may be formed of a suitable material, for example a ceramic insulating material, such as zirconia coated on the inner surfaces of the clamps  441 ,  442 , if desired. The insulation  472  is positioned against the surface of the rifle barrel  470  in the assembled position. The present invention should not be limited, however, to the illustrated arrangement. In an alternative embodiment of the invention shown in FIG. 8, heat insulation is provided by spacer lugs  448  located on the inside of the clamps  441 ,  442 . The lugs  448  provide air spaces  449  between the rifle barrel  470  and the clamps  441 ,  442  which provide the desired heat insulation.  
         [0038]    In a known laser simulation system, the user pulls a trigger to fire a blank cartridge to simulate the firing of an actual round and, in response, a sensor on the laser simulation system transmitter triggers the laser. The player identification and transmitter type can be encoded on the laser beam using a laser simulation system code. An electronic controller is connected through an amplifier to the optical detectors to decode the output signals thereof and provide an indication that the person carrying the receiver has been hit by the laser. It is possible, however, for a user to simulate the firing of a blank cartridge in some systems without actually firing a blank by manipulating the rifle to “re-coil” such that the laser simulation system transmitter is operated. Thus, the laser shot from that transmitter can go unrecognized, giving the user an unfair advantage.  
         [0039]    To overcome these problems, the present invention provides a laser simulation system transmitter that is triggered in response to the heat and/or pressure generated by the blank ammunition gasses upon firing. This provides a way to ensure that the transmitter is only initiated when the user actually pulls the trigger (not shown). Still referring to FIGS. 7 and 8, the sight block  440  may be used to provide a port  473  through which a heat sensor  474  may be inserted into the rifle barrel. The heat sensor  474  passes through the port  473  to provide a signal to the apparatus  410  responsive to the heat of combustion when a blank munition is fired in the rifle, for purposes discussed below. The hot combustion gasses flow through a passage  475  in the barrel  470 , to a passage  476  in the block  440 . The port  473  opens to the passage  476 . The heat sensor signal may be used to prevent the user from manipulating the laser simulation system.  
         [0040]    As shown in FIG. 4, the body  420  may also have right and left casings  422 ,  423  for receiving electronic and optical components for use in the multi-laser apparatus. Cavities or chambers  462 ,  463  (FIG. 6) are formed in the right and left casings  422 ,  423 . Components may also be located in a body cavity or chamber  460 . The body cavity  460  may also be used to contain components that connect the components in the side cavities or chambers  462 ,  463 . The front portions of the body cavity  460  are enclosed by right, left and center casing portions  422 ,  423 ,  425 . The center casing portion  424  fits into a casing slot  415  located in the cover  412 . The casings  422 ,  423  may be arranged to straddle or wrap at least partially around the sight block  440  and/or the rifle barrel  470 . Thus, the assembly  410  may have a saddle-shaped construction.  
         [0041]    Referring now to FIG. 5, there is shown a gum sight  450  that can be flipped up from the cover  412 . The flipped-up position is shown in phantom lines in FIG. 5. The retracted position for when the sight is not being used is shown in solid lines in FIG. 5. The sight  450  may be hinged to the cover  412  by a suitable hinge mechanism  452 ,  453 ,  454 ,  455 . The hinge mechanism may include a lever  452 , a pin  453 , and a number of detents  454  for receiving the lever  452  which may be opened or closed in the direction of arrows  456 . The pin  453  may be located in a housing portion  455 .  
         [0042]    If desired, the apparatus  410  may be provided with a suitable hinged lens cap  492  for preventing dirt or water from reaching the lens system discussed in more detail below.  
         [0043]    Referring now to FIG. 6 there is shown one arrangement by which the optical and electrical components of the apparatus are located within the body  420 . As shown, the optical guide enclosure  484  is located longitudinally within the central cavity  460 . The enclosure  484  has an enlarged end  485  that receives a triple lens system  490 . The lens cover  492  is located on the front of the body  420  to protect the lens triplet  490 . The back end of the enclosure  490  receives a fiber input/output device or connector  494 . The enclosure  484  diverges by an amount approximately equal to the angle of divergence from the optical fiber at the input/output device  494 .  
         [0044]    The fiber input/output device  494  receives optical signals and inputs return signals into a multiplexer in a manner described above in connection with FIGS.  1 - 3 . The input signals are generated by three or more laser sources. The laser sources  500 ,  502  are located within the cavity  460 ,  462 ,  463  and are connected to the input/output device  494  by suitable optical fibers  504 ,  506 ,  508  and optical components. All of the optical fibers, components and sources may be located within the same cavity  460 ,  462 ,  463 .  
         [0045]    The laser sources  500 ,  502  and other electrical and optical components and fibers  504 ,  508  may be assembled on suitable circuit boards  510 ,  512 . The circuit boards  510 ,  512  are located in the right and left chambers  462 ,  463 . The components  500 ,  502  may be assembled on the boards  510 ,  512  before the boards  510 ,  512  are located in the chambers  462 ,  463 . Output fibers  504 ,  508  from the laser sources  500 ,  502  are coupled to the input/output fiber  506  through a multiplexer and other components as described in the above-mentioned pending application filed concurrently herewith. If desired, an additional circuit board may be located in the center chamber  461 .  
         [0046]    A suitable digital compass may be provided on or in the body  420  to provide the user with azimuth and positional location data. Such devices are known per se. The present invention may be used to integrate them within a compact rugged package  420 ,  440  for use with other functional devices.  
         [0047]    If desired, an infrared illuminator lens  491  (FIG. 6) may be provided adjacent the optical guide enclosure  484 . The lens  491  may be connected to an input fiber  591 . Infrared energy may be supplied to the fiber  591  in the manner described above in connection with FIGS.  1 - 3 . By providing the lens  491  in the same package as the lens system  490 , a wide variety of optical functional devices may be supplied in a relatively compact package.  
         [0048]    Reference has been made to preferred embodiments in describing the invention. However, additions, deletions, substitutions, or other modifications which would fall within the scope of the invention defined in the claims may be implemented by those skilled in the art without departing from the spirit or scope of the invention. For example, the invention is not limited for use with rifles. The invention may also be used with other aimable devices, such as binoculars. Accordingly, the invention is not to be considered as limited by the foregoing description, but is only limited by the scope of the appended claims.  
         [0049]    The entire disclosures of U.S. patent application Ser. No. 09/549,497, filed Apr. 14, 2000 and U.S. Provisional Patent Application No. 60/197,777, filed Apr. 14, 2000, are expressly incorporated herein by reference.