Patent Publication Number: US-2021172704-A1

Title: Optical bench

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of U.S. provisional application No. 62/743,737, filed Oct. 10, 2018. The aforementioned application is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The present disclosure relates generally to the field of weapon sights and, in particular, to an optical bench for a laser sight and opto-mechanical assemblies and laser sights employing the same. 
     Reflex sights are generally known in the art and typically include a battery-powered light source such as an LED or laser for projecting an illuminated reticle image, such as a colored (e.g., red or green) dot. Such reflex sights include a lens assembly (typically non-magnifying), e.g., employing a beam splitter, dichroic mirror, or similar reflective coating or film that reflects light from the light source along the viewing axis of the lens so that the viewer sees both the target field of view and the projected reticle image superimposed thereon to aid the user in aiming the barrel of a firearm or other weapon. Laser sights are also known and comprise one or more laser devices configured to emit a laser beam onto a target for the purpose of aiding the user in aiming the barrel of a firearm or other weapon. 
     In each case, the alignment of the sight must be adjusted with respect to the barrel of the weapon (bore sighted) so that the position of the emitted light (i.e., the reticle image on the lens in the case of a reflex sight or the position of the laser beam on the target in the case of a laser sight) corresponds with or intersects the trajectory path of the fired projectile at the target. Adjusting the alignment of the sight typically involves adjusting the horizontal alignment (windage) and vertical alignment (elevation) using threaded adjustment screws, and can be a time consuming process. In the case of multiple sights, the horizontal and vertical alignment must be performed for each sight. In addition, even when a sight has been bore sighted for a particular weapon it may be necessary to re-bore sight for different conditions, including changes in distance to target (for example, long range vs. short range or close combat conditions), differences in muzzle velocity or projectile speed for different types of ammunition rounds, and changes in incline (e.g., level shooting vs. elevated or depressed firing position relative to target), and so forth. 
     Reflex sights typically use a glass lens mounted in a frame. Because plastic lens materials have a higher coefficient of thermal expansion than glass, plastic lenses have not been widely adapted for use in reflex sights. Because plastic lenses are less expensive than glass lenses, it would be desirable to provide a lens mount which could accommodate the increased thermal expansion associated with a plastic lens, thereby lowering manufacturing costs of the sight. 
     SUMMARY 
     In one aspect, the present disclosure contemplates a new and improved sight apparatus including an optical bench structure configured to support optical assemblies and electronic and electrical components. 
     In another aspect, the optical bench structure is monolithic, formed via an additive manufacturing processes. 
     In another aspect, the optical bench structure includes one or more flexures for adjustment of elevation and windage of associated optical elements. 
     In another aspect, the optical bench structure includes one or more flexures for adjustment of the pointing vector of laser sight assemblies. 
     In another aspect, the optical bench structure includes one or more flexures configured for optothermal stability of optical assemblies. 
     In another aspect, the reflex sight apparatus includes a plastic, e.g., acrylic reflex lens. In a further aspect, the plastic reflex lens includes an embedded iron (mechanical) sight. 
     In another aspect, a weapon sight assembly includes an optical bench, the optical bench being a single-piece structure having no bonded or bolted joints, a reflex sight portion disposed on the optical bench, wherein the reflex sight portion includes a reticle receiving portion, and a lens assembly disposed on the optical bench, wherein the lens assembly includes a reflex lens. 
     In another aspect, a weapon sight assembly includes an optical bench having one or more reflex lens mounting arms, wherein each of the one or more reflex lens mounting arms are configured to retain the reflex lens. 
     In another aspect, a weapon sight assembly includes a reticle sight portion having a light source and a reticle frame, and wherein the reticle light source assembly is configured to be received by the reticle receiving portion. 
     In another aspect, a weapon sight assembly includes a reflex lens configured to function as a partially reflective mirror. 
     In another aspect, a weapon sight assembly includes one or more threaded adjustment screws for adjusting elevation and/or windage of the reflex sight portion. 
     In another aspect, a weapon sight assembly includes a rear sight mounting portion and an iron sight system having a front sight embedded in the reflex lens, and a rear sight, wherein the rear sight is attached to the rear sight mounting portion. 
     In another aspect, a weapon sight assembly includes one or more reflex lens mounting arms having a horizontal arm portion and two upstanding arm portions, wherein the two upstanding arm portions are configured to claim a side portion of the reflex lens. 
     In another aspect, a weapon sight assembly includes an optical bench, the optical bench being a single-piece structure having no bonded or bolted joints, a laser receptacle portion disposed on the optical bench, the laser receptacle portion having one or more receptacles and one or more aiming laser assemblies, and a bore sight adjustment lever disposed on the optical bench, the bore sight adjustment lever extending from the laser receptacle portion. 
     In another aspect, a weapon sight assembly includes one or more receptacles configured to support one or more laser emitter. 
     In another aspect, a weapon sight assembly includes one or more laser emitters. In a further aspect, the one or more laser emitters are a visible target point laser, a visible target aiming laser, an infrared target pointing laser, an infrared target aiming laser, an infrared illuminator laser, and/or an infrared flood light laser. 
     In another aspect, a weapon sight assembly includes one or more receptacles configured to substantially align with one or more laser diode receptacles. 
     In another aspect, a weapon sight assembly includes one or more aiming laser assemblies which are a laser emitter and/or a laser lens assembly. 
     In another aspect, a weapon sight assembly includes one or more lens assemblies having a laser focusing lens and a lens holder, wherein the lens holder comprises a laser focusing lens and a lens holder. 
     In another aspect, a weapon sight assembly includes one or more flexures for directional adjustment of the one or more aiming laser assemblies, a platform portion disposed on the optical bench, wherein the platform portion has one or more threaded openings, and one or more threaded screws, wherein the one or more threaded screws are configured to rotatably engage with the one or more threaded openings. 
     In another aspect, a weapon sight assembly includes a bench surface, wherein the one or more threaded screws are configured to rotatably engage with the bench surface to adjust the orientation of the bench surface with respect to the platform portion. 
     In another aspect, the bore sight adjustment lever includes a windage adjustment bearing surface disposed on the bore sight adjustment lever, the windage adjustment bearing surface configured to engage with a windage adjustment assembly and a windage counter spring bearing surface disposed on the bore sight adjustment lever, the windage counter spring bearing surface configured to engage with a windage adjustment counter spring. The bore sight adjustment lever further includes an elevation adjustment bearing surface disposed on the bore sight adjustment lever, the elevation adjustment bearing surface configured to engage with an elevation adjustment assembly and an elevation counter spring bearing surface disposed on the bore sight adjustment lever, the elevation counter spring bearing surface configured to engage with an elevation counter spring. 
     In another aspect, a weapon sight assembly includes a windage adjustment assembly including a first sleeve having an internal helical thread, a rotatable barrel having an external helical thread complimentary to the internal helical thread, and a bearing member. 
     In another aspect, a weapon sight assembly includes an elevation adjustment assembly including a sleeve having an internal helical thread, a rotatable barrel having an external helical thread complimentary to the internal helical thread, and a bearing member. 
     In another aspect, a weapon sight assembly includes an optical bench, the optical bench being a single-piece structure having no bonded or bolted joints, a reflex sight portion disposed on the optical bench, wherein the reflex sight portion includes a reticle receiving portion, a lens assembly disposed on the optical bench, wherein the lens assembly includes a reflex lens, a laser receptacle portion disposed on the optical bench, the laser receptacle portion comprising one or more receptacles and one or more aiming laser assemblies, a bore sight adjustment lever disposed on the optical bench, the bore sight adjustment lever extending from the laser receptacle portion, and a mounting member, wherein the mounting member is connected to the optical bench by one or more flexures. 
     In another aspect, a monolithic structure for adjusting and maintaining coalignment of lasers is provided. 
     In another aspect, a method for adjusting and maintaining coalignment of lasers is provided. 
     In another aspect, a method and apparatus for mounting and athermalization of a plastic lens for high shock environments is provided. 
     In another aspect, a method of manufacturing an optical bench having a single-piece structure is provided. 
     In another aspect, a method of additively manufacturing an optical bench into a single-piece structure having no bonded or bolted joints is provided. Additively manufacturing the optical bench may include: 
     a. additively manufacturing a reflex sight assembly mounting portion; 
     b. additively manufacturing a reflex lens mounting arms; 
     c. additively manufacturing a pivot flexure between the reflex sight assembly mounting portion and the reflex lens mounting arms; 
     d. additively manufacturing a pointing laser receptacle portion; 
     e. additively manufacturing a pivot flexure between the pointing laser receptacle portion and the reflex sight assembly mounting portion; 
     f. additively manufacturing a mounting portion; 
     g. additively manufacturing a windage and elevation adjustment lever; and 
     h. additively manufacturing a pivot flexure between the mounting portion and the windage and elevation adjustment lever. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention. 
         FIG. 1  is an isometric view of an exemplary sight embodying the present invention. 
         FIG. 2  is an isometric view of an exemplary optical bench for a combined reflex and laser aiming sight in accordance with an exemplary embodiment of the invention, taken generally from above, the front, and the left side. 
         FIG. 3  is an isometric view of the optical bench appearing in  FIG. 2 , taken generally from below, the front, and left side. 
         FIG. 4  is an isometric view of the optical bench shown in  FIG. 3 , taken generally from above, the back, and the left side. 
         FIG. 5  is an isometric view of the optical bench shown in  FIG. 3 , taken generally from the back, bottom, and left side. 
         FIG. 6  is a front elevation view of the optical bench shown in  FIG. 2 . 
         FIG. 7  is a rear elevation view of the optical bench shown in  FIG. 2 . 
         FIG. 8  is a top plan view of the optical bench shown in  FIG. 2 . 
         FIG. 9  is a bottom plan view of the optical bench shown in  FIG. 2 . 
         FIG. 10  is a left side elevation view of the optical bench shown in  FIG. 2 . 
         FIG. 11  is an isometric view of an optical bench assembly comprising the optical bench appearing in  FIG. 2  with optical components attached, taken generally from above, the front, and the left side. 
         FIG. 12  is an isometric view of the optical bench assembly appearing in  FIG. 11 , taken generally from below, the front, and the left side. 
         FIG. 13  is an isometric view of the optical bench assembly appearing in  FIG. 11 , taken generally from above, the rear, and the left side. 
         FIG. 14  is an isometric view of the optical bench assembly appearing in  FIG. 11 , taken generally from below, the rear, and the left side. 
         FIG. 15  is an isometric view of the optical bench assembly shown in  FIG. 11 , and further illustrating a flex cable connecting components of the sight, taken generally from below, the back, and the right side. 
         FIG. 16  is a left side elevation view of the optical bench assembly shown in  FIG. 11 . 
         FIG. 17  is rear elevation view of the optical bench assembly shown in  FIG. 11 . 
         FIG. 18  is a left side cross-sectional view of the optical bench assembly taken along the lines  18 - 18  appearing in  FIG. 17 . 
         FIG. 19  is an isometric view of the optical bench assembly appearing in  FIG. 11  and further comprising exemplary windage and elevation adjustment assemblies, taken generally from above, the front, and the left side. 
         FIG. 20  is an isometric view of the optical bench assembly shown in  FIG. 19 , taken generally from above, the back, and the left side. 
         FIG. 21  is an isometric view of the optical bench assembly shown in  FIG. 19 , taken generally from above, the back, and the right side. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, wherein like reference numerals represent like or analogous components throughout the several views,  FIG. 1  illustrates an exemplary sight apparatus  110  including a reflex sight subassembly  112  having a housing or cover  114  and an aiming or pointing (and/or illumination) laser subassembly  116  having a housing  118 .  FIGS. 2-10  illustrate an optical bench  120  operable to support the optical (including electro-optical) components of the reflex sight subassembly  112  and the pointing laser subassembly  116 .  FIGS. 11-18  illustrate an optical bench assembly comprising the optical bench  120  and the associated optical components.  FIGS. 19-21  illustrate the optical bench assembly appearing in  FIGS. 11-18  in combination with associated elevation and windage adjustment assemblies. 
     As used herein, unless specifically stated otherwise, the terms “top,” “bottom,” “upper,” “lower,” “left,”, “right”, “horizontal,” “vertical,” “front”, and “rear,” and other such terms which are dependent on orientation are intended to refer to the orientation of the optical bench as shown in the drawings and consistent with the Brief Description of the Drawings, above. As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of such elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising”, “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. 
     In certain embodiments, the optical bench  120  is formed as a single-piece structure in an additive manufacturing process. Additive manufacturing (also known as rapid prototyping and 3D printing) is the process of joining materials to make objects from 3D model data, usually layer upon layer, in contrast to casting or molding processes wherein a liquid or pliable material is poured or otherwise shaped using a mold or matrix of a desired shape, and subtractive manufacturing processes such as milling, machining, turning on a lathe, or other controlled material removal process. Exemplary additive manufacturing processes include stereolithography, fused deposition modeling, selective laser sintering, direct metal laser sintering, selective laser melting, and the like. 
     In certain embodiments of an additive manufacturing process operable to manufacture the optical bench  120 , the optical bench  120  is first modeled using computer-aided design (CAD) software or 3D-modeling software. Next, a digital file representative of the three-dimensional shape of the optical bench  120  is uploaded to an additive manufacturing computer where the pre-processing software slices the model into a number of thin layers. An additive manufacturing machine lays down a build material such as powdered metals, powdered plastics, UV curable polymers, and others, in layer-upon-layer fashion to fabricate the optical bench  120 . In certain embodiments, the optical bench  120  is formed of sintered titanium, although other materials are also contemplated, including plastics, other metals, and ceramics. It will be recognized that the optical bench  120  may be manufactured using additive manufacturing processes as are generally known, as well as modifications or improvements to additive manufacturing processes developed in the future. 
     In certain embodiments, the optical bench  120  comprises a monolithic or single-piece mechanical structure having a reflex sight mounting portion, designated generally as A, reflex lens mounting arms, designated generally as B, an aiming and/or illumination laser receptacle portion, designated generally as C, a mounting portion, designated generally as D, for securing the optical bench within the housing  118  of the sight apparatus  110 , a bore sight adjustment lever, designated generally as E, and a rear sight mounting portion, designated generally as F. Unless specifically stated otherwise, the terms “aiming laser,” “pointing laser,” and “targeting laser” are used herein interchangeably to mean a laser generally aligned with the barrel of a weapon or firearm (with or without allowance for ballistic drop, windage, distance to target, offset between the beam axis and the axis of the barrel, and so forth) for placing a spot on a desired target, without regard to nuances in connotation. 
     The reflex sight mounting portion A, comprises a reticle platform or surface  122  having a plurality of openings  124  for receiving threaded fasteners  126  securing a reticle light source assembly  128  to the platform  122 . The reticle light source assembly  128  includes a light source  130  carried on a reticle sled or frame  132 . In certain embodiments, the frame  132  is formed of aluminum. The light source  130  may be any suitable light source, such as an LED or laser, e.g., an eye-safe laser. The light source assembly  128  is attached to a surface  122  via the threaded fasteners  126  engaging aligned openings in the reticle sled  132 . 
     The light source  130  emits light that impinges on a lens assembly  134 . The lens assembly  134  functions as a partially reflective mirror (e.g., beam splitter or dichroic mirror), for example, which may include a reflective coating or film therein to reflect a portion of the light emitted from the light source  130  back toward the user. 
     In certain embodiments, the light from the light source  130  is preferably collimated, e.g., using a collimating lens. The lens assembly  134  also allows light reflected from the target field of view to pass through, wherein the collimated light from the light source  130  appears as a superimposed reticle on the target field of view. The superimposed reticle may appear as a dot, e.g., a red or green dot, although other reticle colors and shapes, such as rings and cross hairs are also contemplated. 
     The horizontal and vertical position of the collimated light from the light source  130  on the lens assembly  134  is adjusted using threaded adjustment screws  136 . The adjustment screws  136  therefore provide elevation and windage adjustments, respectively, for the reflex sight subassembly  112 . Once the light source  130  and the laser elements of the laser sight, as described below, have been coaligned, a potting compound may be used to maintain the light source  130  in its aligned position. In certain embodiments, the lens assembly  134  includes a plastic reflex lens, such as an acrylic reflex lens. In other embodiments, the lens assembly  134  includes a glass lens. 
     In certain embodiments, sight apparatus includes alignment markers, i.e., so-called “iron sights.” The iron sights may be used, for example, as a backup aiming system in the event the unit  110  malfunctions or the power supply is depleted. In the illustrated embodiment, the lens assembly  134  includes an iron sight system comprising a front sight  138  embedded in the reflex lens and a rear sight  140  attached to the rear sight mounting portion F. Although a post type front sight is illustrated, it will be recognized that other configurations, such as bead or ring type front sight, are also contemplated. The rear sight  140  is attached to the a rear sight mounting portion F via threaded fasteners  144  engaging openings  146  in the rear sight mounting portion F. In the illustrated embodiment, the rear sight  140  is configured as an open sight having a notch  142 . It will be recognized that other rear sight configurations are also contemplated, such as a rear sight having an aperture instead of a notch. 
     The optical bench  120  includes a pair of flexures  150  for adjusting the pointing direction of the aiming laser assemblies  152 , each of which comprises a laser diode  154  and an aiming laser lens assembly  156 . The aiming laser lens assembly  156 , in turn, comprises a lens  158 , e.g., a collimating lens, and a lens mount  160 . The rotation or pivoting movement of the aiming laser assembly  156  about a transverse horizontal axis in relation to the platform  122  is adjusted using threaded adjustment screws  162   a  and  162   b . The screw  162   a  passes through an enlarged diameter clearance opening  164  in the platform  122  and rotatably engages a threaded opening  166  a bench surface  168  in the aiming laser portion C. Rotation of the screw  162   a  selectively moves the bench surface in relation to the platform  122  in a desired direction depending on the direction of rotation. The screw  162   b  engages a threaded opening  170  in the platform  122  and bears against the bench surface  168 . Rotation of the screw  162   b  selectively moves the bearing end of the screw  162   b  toward or away from the bench surface  168 , depending on the direction of rotation. In this manner, the orientation of the bench surface  168  with respect to the platform  122  can be adjusted, with pivoting movement occurring by torsion at the flexures  150 , to provide an elevation adjustment of the aiming laser assembly  152 . 
     The horizontal position (windage) of the aiming laser assemblies  152  is adjusted using threaded adjustment screws  172   a  and  172   b . The flexures  150  are resilient, allowing the aiming laser assemblies  152  to pivot about the short axis of the flexures  150 . The screw  172   a  passes through an enlarged diameter clearance opening  174  in a bench side platform  176  and rotatably engages a threaded opening  178  a bench side surface  180  in the aiming laser portion C. Rotation of the screw  172   a  selectively moves the bench side surface  180  in relation to the bench side platform  176  in a desired direction depending on the direction of rotation. The screw  172   b  engages a threaded opening  182  in the side platform  176  and bears against the bench side surface  180 . Rotation of the screw  172   b  selectively moves the bearing end of the screw  172   b  toward or away from the bench side surface  180 , depending on the direction of rotation. In this manner, the position of the bench side surface  180  with respect to the side platform  176  can be adjusted, with movement occurring by bending pivoting movement (flexion) at the flexures  150 , to adjust the windage of the aiming laser. 
     The lens assembly  134  is retained by a pair of flexible mounting arms B, situated on opposing sides of the lens assembly  134 . In certain embodiments, each lens mounting arm B includes a horizontal (in the orientation shown in  FIG. 10 ) arm  184  and two upstanding arms  186   a ,  186   b , defining a split lens holder, extending from the distal end of the arm  184 . It will be recognized that the illustrated arm geometries are exemplary only and other arm geometries are contemplated. The arms  186   a ,  186   b  are configured to clamp a side portion or protrusion  135  on opposite sides of the lens assembly  134 . In alternative embodiments, the split lens holder may be omitted. The lens assembly flexures B are resilient with multiple degrees of movement, e.g., flexion of the arms  184 , torsion of the arms  184 , and flexion of the arms  186   a ,  186   b , to accommodate thermal expansion and contraction of the lens assembly  134 . The resiliency of the lens assembly flexures B allows for compensation for the expansion of the lens assembly  134  induced by heat, for example, resulting from discharge of the weapon or other heat source. In certain embodiments, the lens assembly flexures B are configured to be able to spread outward and retract inward to allow for lens assembly expansion and contraction while substantially retaining the lens assembly  134  in place. This advantageously allows for the use of lens materials with a relatively high coefficient of thermal expansion, such as plastics, thereby enabling a reduction in manufacturing costs. 
     The laser receptacle portion C includes one or more receptacles  190  formed in the portion C for supporting one or more laser emitters  154 , e.g., laser diodes. In certain preferred embodiments, the laser receptacle portion C has three receptacles  190  and three respective laser emitters  154 . In certain embodiments, the laser emitters include a visible target pointing or aiming laser, an infrared (IR) target pointing or aiming laser, and an IR illuminator or flood light laser. In certain embodiments, the coalignment of laser emitters  154  is effected purely mechanically. 
     One or more lens receptacles  192  are formed in the portion C and each is optically aligned with a respective one of the laser diode receptacles  190  and are configured to receive a lens assembly  156 . Each lens assembly  156  includes a laser focusing lens  158  and a lens holder  160 . The lens holder  160  includes external threads  202  which are complementary with internal threads  194  in the receptacles  192 . In certain embodiments, one or more of the receptacles  192  include an axially extending slot or gap  204 , thereby defining resiliently flexible threaded flexure elements  206 , which are curved arms configured to resiliently expand outward. In certain embodiments, the threaded end of the lens holders  160  are configured to have negative clearance in relation to the internal diameter of the receptacles  192 , tending to urge the threaded flexure elements  206  outward and creating a spring force against the lens holder  160 . The resiliency of the threaded flexure elements  206  allows for rotational adjustment of the lens assembly  156  by axially advancing or retracting (depending on the direction of rotation) the lens, i.e., to position the laser diode at the focal length of the lens, while limiting movement during operation. 
     In the illustrated embodiment, the optical bench includes two lens receptacles  192  with resilient flexure elements  206  on opposite sides of a center lens receptacle  192   a . In certain embodiments, the receptacles  192  are configured to hold lens assemblies for aiming/pointing lasers (e.g., visible and IR laser diodes) and the center lens receptacle  192   a  is configured to hold a lens assembly for an illumination/flood laser (e.g., IR laser diode). It will be recognized that other configurations with other numbers of lasers and lasers having other wavelengths are contemplated. 
     The optical bench mounting portion D includes a mounting member  208  having one or more apertures  210  for receiving one or more fasteners (not shown), to fasten the optical bench within the housing  118 . 
     The mounting member  208  is connected to a first flexure  212  comprising a generally horizontal web of material configured to flex or pivot about a horizontal axis and resist flexing about vertical axis. The first flexure  212 , in turn, is connected to a second flexure  214  comprising a generally vertical web extending between the first flexure  212  and the laser receptacle portion C. The second flexure  214  is configured to flex or pivot about a vertical axis and resist flexing about a vertical axis. 
     The resiliency of the first flexure  212 , allows the optical bench  120  to pivot in response to a vertical force exerted on the optical bench  120 , thereby allowing alignment of the optical bench  120  to be adjusted relative to the housing, thus providing a vertical (elevation) adjustment of the laser beams emitted by the lasers. Likewise, the resiliency of the second flexure  214  allows the optical bench  120  to pivot in response to a horizontal force exerted on the optical bench  120 , thereby allowing alignment of the optical bench  120  to be adjusted relative to the housing  118 , thus providing a horizontal (windage) adjustment of the laser beams emitted by the lasers. 
     The bore sight adjustment lever E comprises an arm  216  extending from the laser receptacle portion C. The distal end of the arm  216  includes a generally horizontal elevation adjustment bearing surface  218  and an elevation counter spring bearing surface  220  opposite the elevation adjustment bearing surface  218 . The distal end of the arm  216  also includes a generally vertical windage adjustment bearing surface  222  and a windage counter spring bearing surface  224  opposite the windage adjustment bearing surface  222 . 
     An elevation adjustment assembly  226  is mounted to the housing  118  and includes an elevation bearing member  228 , which bears against the surface  218 . An elevation adjustment counter spring  230  is captured within the housing and bears against the surface  220 . Rotational adjustment of the elevation adjustment assembly  226  in one direction causes the lever arm  216  to move downward against the bias of the spring  230  and causes the optical bench  120  to pivot about the first flexure  212 , thereby raising the aim point of the aiming lasers in relation to the housing  118  and, in turn, relative to the barrel of the weapon to which the unit  110  is attached. 
     Similarly, rotational adjustment of the elevation adjustment assembly  226  in the opposite direction allows the spring  230  to urge the lever arm  216  upward and causes the optical bench  120  to pivot about the first flexure  212 , thereby lowering the aim point of the aiming lasers in relation to the housing  118  and, in turn, relative to the barrel of the weapon to which the unit  110  is attached. 
     A windage adjustment assembly  232  is mounted to the housing and includes a windage bearing member  234 , which bears against the surface  222 . A windage adjustment counter spring  236  is captured within the housing  118  and bears against the surface  224 . Rotational adjustment of the windage adjustment assembly  232  in one direction causes the lever arm  216  to move to the left against the bias of the spring  236  and causes the optical bench  120  to pivot about the second flexure  214 , thereby moving the aim point of the aiming lasers to the right in relation to the housing  118  and, in turn, relative to the barrel of the weapon to which the unit  110  is attached. 
     Similarly, rotational adjustment of the windage adjustment assembly  232  in the opposite direction allows the spring  236  to urge the lever arm  216  to the right and causes the optical bench  120  to pivot about the second flexure  214 , thereby moving the aim point of the aiming lasers to the left in relation to the housing  118  and, in turn, relative to the barrel of the weapon to which the unit  110  is attached. 
     In certain embodiments, the elevation adjustment assembly  226  includes a sleeve  238 , which rotatably receives a rotatable barrel  240 . The sleeve  238 , in turn, is received within an opening  242  in the housing  118 . The rotatable barrel  240  includes the bearing member  228  which protrudes from the open end of the sleeve and engages the surface  218  on the lever arm  216  as described above. An exterior helical thread (not shown) on the barrel  240  engages a complementary interior thread (not shown) on the interior of the sleeve  238 , such that rotation of the barrel in one direction causes the bearing member to advance toward the respective surface against the urging of the spring and rotation of the barrel in the other direction causes the bearing member to move away from the respective bearing surface. 
     In certain embodiments, the windage adjustment assembly  232  includes a sleeve  244 , which rotatably receives a rotatable barrel  246 . The sleeve  244 , in turn, is received within an opening  248  in the housing  118 . The rotatable barrel  246  includes the bearing member  234  which protrudes from the open end of the sleeve and engages the surface  222  on the lever arm  216  as described above. An exterior helical thread (not shown) on the barrel  246  engages a complementary interior thread (not shown) on the interior of the sleeve  244 , such that rotation of the barrel in one direction causes the bearing member to advance toward the respective surface against the urging of the spring and rotation of the barrel in the other direction causes the bearing member to move away from the respective bearing surface. 
     In certain embodiments, the elevation and windage adjustment assemblies  226 ,  232  may be as described in commonly owned U.S. Pat. No. 9,752,853, the entire contents of which are incorporated herein by reference. 
     As best seen in  FIG. 15 , in certain embodiments the optical bench includes a flex cable  250 , e.g., comprising circuit elements and conductive traces on a flexible circuit substrate configured to connect electrical components, such as laser diodes, light sensor, and reticle light element, power supply, and so forth. Other flexible conductors are contemplated, such as a ribbon cable or the like. 
     Various aspects of the present development are contemplated, including the following: 
     An optical bench for supporting a reflex sight in a weapon-mounted sight assembly, the optical bench comprising a reflex sight mounting portion having a first surface for receiving a reticle light source, a first reticle lens mounting arm spaced apart from a second reticle lens mounting arm, the first and second reticle lens mounting arms attached to the reflex sight mounting portion, and the first and second reticle lens mounting arms configured to engage opposite sides of a reticle lens to support the reticle lens in an optical path of the reticle light source, the first and second reticle lens mounting arms being sufficiently resilient to accommodate thermal expansion and contraction of the reticle lens. 
     An optical bench wherein the reflex sight mounting portion is formed with the first and second reticle lens mounting arms as a monolithic structure. 
     An optical bench wherein the monolithic structure is defined as a series of additive manufactured layers built upon each other. 
     An optical bench wherein the first and second reticle lens mounting arms are resilient with multiple degrees of movement. 
     An optical bench wherein each of the first and second reticle lens mounting arms have a horizontal segment attached to reflex sight mounting portion and a vertical segment disposed at a distal end of the horizontal segment. 
     An optical bench wherein the horizontal segment is configured for both flexion movement and torsion movement responsive to thermal expansion and contraction of the reticle lens, and each vertical segment comprises a pair of upstanding arms defining a clip configured to engage a complementary protrusion on the reticle lens, wherein the pair of upstanding arms are configured for flexion movement responsive to thermal expansion of the reticle lens. 
     An optical bench further comprising one or both of a reticle frame removably attached to the first surface, the reticle frame configured to carry the reticle light source and a rear iron sight removably attached to the first surface. 
     An optical bench further comprising an aiming laser portion and one or more aiming laser flexures connecting the aiming laser portion to the reflex sight mounting portion, wherein the aiming laser portion is pivotable about the one or more aiming laser flexures for adjusting an angular orientation of the aiming laser portion in relation to the reflex sight mounting portion. 
     An optical bench wherein the aiming laser portion is configured to pivot responsive to torsion, flexion, or both at the one or more flexures. 
     An optical bench wherein each of the one or more flexures extends transversely with respect to an optical axis of the optical bench and each of the one or more flexures has a long axis and a short axis, the optical bench further comprising a horizontal bench surface spaced apart from the reticle mounting portion, a first set of one or more threaded fasteners which are rotatable to move the reticle mounting portion in relation to the horizontal bench surface, a bench side surface attached to the reticle mounting portion, a vertical bench surface spaced apart from the bench side surface, a second set of one or more threaded fasteners which are rotatable to move the bench side surface in relation to the vertical bench surface, wherein rotation of the first set of one or more threaded fasteners causes pivoting movement occurring by torsion at the one or more flexures, thereby providing an elevation adjustment of the aiming laser portion in relation to the reticle mounting portion, and, wherein rotation of the second set of one or more threaded fasteners causes pivoting movement occurring by flexion at the flexures, thereby providing a windage adjustment of the aiming laser portion in relation to the reticle mounting portion. 
     An optical bench wherein the aiming laser portion includes at least one laser receptacle for receiving a laser emitter and at least one lens receptacle for supporting a laser lens assembly in an optical path of the laser emitter. 
     An optical bench wherein the at least one lens receptacle has a internally threaded surface configured to engage complementary external threads on the laser lens assembly, and further wherein the at least one lens receptacle has a gap defining resiliently flexible and outwardly expandable curved flexure elements. 
     An optical bench further comprising an optical bench mounting portion attached to the aiming laser mounting portion, the optical bench mounting portion configured to fasten the optical bench within a housing of the weapon mounted sight assembly. 
     An optical bench further comprising a bore sight lever attached to the optical bench mounting portion, the bore sight lever having a horizontal bearing surface that is movable to provide an elevation bore sight adjustment and a vertical bearing surface that is movable to provide a windage bore sight adjustment. 
     An optical bench wherein the optical bench mounting portion includes a first bore sight flexure configured to flex responsive to movement of the bore sight lever in a first direction and a second bore sight flexure configured to flex responsive to movement of the bore sight lever in a second direction orthogonal to the first direction. 
     A weapon sight assembly comprising an optical bench supported in a housing, the optical bench including a reflex sight mounting portion having a first surface for receiving a reticle light source; and a first reticle lens mounting arm spaced apart from a second reticle lens mounting arm, the first and second reticle lens mounting arms attached to the reflex sight mounting portion, and the first and second reticle lens mounting arms configured to engage opposite sides of a reticle lens to support the reticle lens in an optical path of the reticle light source, the first and second reticle lens mounting arms being sufficiently resilient to accommodate thermal expansion and contraction of the reticle lens, a reticle light source received within the housing and attached to the first surface, and a reticle lens attached to the first and second reticle mounting arms. 
     A weapon sight assembly wherein the reticle lens is formed of a plastic material. 
     A weapon sight assembly wherein the optical bench further includes an aiming laser portion and one or more aiming laser flexures connecting the aiming laser portion to the reflex sight mounting portion, wherein the aiming laser portion is pivotable about the one or more aiming laser flexures for adjusting an angular orientation of the aiming laser portion in relation to the reflex sight mounting portion, the aiming laser portion including at least one laser receptacle receiving a laser emitter and at least one lens receptacle supporting a laser lens assembly in an optical path of the laser emitter. 
     A weapon sight assembly wherein the optical bench further includes an optical bench mounting portion attached to the aiming laser mounting portion, the optical bench mounting portion securing the optical bench within the housing. 
     A weapon sight assembly further comprising a bore sight lever attached to the optical bench mounting portion, the bore sight lever having a horizontal bearing surface that is movable to provide an elevation bore sight adjustment and a vertical bearing surface that is movable to provide a windage bore sight adjustment, an elevation adjustment assembly disposed within the housing and bearing against the horizontal bearing surface, and a windage adjustment assembly disposed within the housing and bearing against the vertical bearing surface. 
     A method of manufacturing an optical bench for a weapon mounted sight assembly comprising additively manufacturing a reflex sight assembly mounting portion and additively manufacturing a pair of opposing reflex lens mounting arms, wherein the pair of opposing reflex lens mounting arms are resilient and flexible and have multiple degrees of movement. 
     A method further comprising additively manufacturing an aiming laser portion and one or more aiming laser flexures connecting the aiming laser portion to the reflex sight mounting portion, wherein the aiming laser portion is pivotable about the one or more aiming laser flexures for adjusting an angular orientation of the aiming laser portion in relation to the reflex sight mounting portion, the aiming laser portion including at least one laser receptacle for receiving a laser emitter and at least one lens receptacle for supporting a laser lens assembly in an optical path of the laser emitter. 
     A method further comprising, optionally, additively manufacturing an optical bench mounting portion, additively manufacturing a windage and elevation adjustment lever extending from the aiming laser portion, and additively manufacturing a pivot flexure between the optical bench mounting portion and the windage and elevation adjustment lever. 
     A weapon sight assembly comprising an optical bench, the optical bench being a single-piece structure having no bonded or bolted joints, a reflex sight portion disposed on the optical bench, wherein the reflex sight portion includes a reticle receiving portion, and a lens assembly disposed on the optical bench, wherein the lens assembly includes a reflex lens. 
     A weapon sight assembly wherein the optical bench comprises one or more reflex lens mounting arms, wherein each of the one or more reflex lens mounting arms are configured to retain the reflex lens. 
     A weapon sight assembly wherein the reticle sight portion comprises a light source and a reticle frame, and wherein the reticle light source assembly is configured to be received by the reticle receiving portion. 
     A weapon sight assembly wherein the reflex lens is configured to function as a partially reflective mirror. 
     A weapon sight assembly further comprising one or more threaded adjustment screws for adjusting one or more of elevation and windage of the reflex sight portion. 
     A weapon sight assembly further comprising a rear sight mounting portion and an iron sight system comprising a front sight embedded in the reflex lens, and a rear sight, wherein the rear sight is attached to the rear sight mounting portion. 
     A weapon sight assembly wherein each of the one or more reflex lens mounting arms comprises a horizontal arm portion and two upstanding arm portions, wherein the two upstanding arm portions are configured to claim a side portion of the reflex lens. 
     A weapon sight wherein the optical bench is formed via an additive manufacturing process. 
     A weapon sight assembly comprising an optical bench, the optical bench being a single-piece structure having no bonded or bolted joints, a laser receptacle portion disposed on the optical bench, the laser receptacle portion comprising one or more receptacles and one or more aiming laser assemblies, and a bore sight adjustment lever disposed on the optical bench, the bore sight adjustment lever extending from the laser receptacle portion. 
     A weapon sight assembly wherein the one or more receptacles is configured to support one or more laser emitter. 
     A weapon sight assembly wherein the one or more laser emitters includes one or more of: a visible target point laser, a visible target aiming laser, an infrared target pointing laser, an infrared target aiming laser, an infrared illuminator laser, and an infrared flood light laser. 
     A weapon sight assembly wherein each of the one or more receptacles is configured to substantially align with one or more laser diode receptacles. 
     A weapon sight assembly wherein each of the one or more aiming laser assemblies comprises a laser emitter and laser lens assembly. 
     A weapon sight assembly wherein each of the one or more lens assemblies comprises a laser focusing lens and a lens holder, wherein the lens holder comprises a laser focusing lens and a lens holder. 
     A weapon sight assembly wherein the optical bench comprises one or more flexures for directional adjustment of the one or more aiming laser assemblies, a platform portion disposed on the optical bench, wherein the platform portion has one or more threaded openings, and one or more threaded screws, wherein the one or more threaded screws are configured to rotatably engage with the one or more threaded openings. 
     A weapon sight assembly wherein the optical bench further comprises a bench surface, wherein the one or more threaded screws are configured to rotatably engage with the bench surface to adjust the orientation of the bench surface with respect to the platform portion. 
     A weapon sight assembly wherein the bore sight adjustment lever comprises a windage adjustment bearing surface disposed on the bore sight adjustment lever, the windage adjustment bearing surface configured to engage with a windage adjustment assembly, a windage counter spring bearing surface disposed on the bore sight adjustment lever, the windage counter spring bearing surface configured to engage with a windage adjustment counter spring, an elevation adjustment bearing surface disposed on the bore sight adjustment lever, the elevation adjustment bearing surface configured to engage with an elevation adjustment assembly, and an elevation counter spring bearing surface disposed on the bore sight adjustment lever, the elevation counter spring bearing surface configured to engage with an elevation counter spring. 
     A weapon sight assembly wherein the windage adjustment assembly is comprised of a first sleeve having an internal helical thread, a rotatable barrel having an external helical thread complimentary to the internal helical thread, and a bearing member. 
     A weapon sight assembly wherein the elevation adjustment assembly is comprised of a sleeve having an internal helical thread, a rotatable barrel having an external helical thread complimentary to the internal helical thread, and a bearing member. 
     A weapon sight assembly comprising an optical bench, the optical bench being a single-piece structure having no bonded or bolted joints, a reflex sight portion disposed on the optical bench, wherein the reflex sight portion includes a reticle receiving portion, a lens assembly disposed on the optical bench, wherein the lens assembly includes a reflex lens, a laser receptacle portion disposed on the optical bench, the laser receptacle portion comprising one or more receptacles and one or more aiming laser assemblies, a bore sight adjustment lever disposed on the optical bench, the bore sight adjustment lever extending from the laser receptacle portion, and a mounting member, wherein the mounting member is connected to the optical bench by one or more flexures. 
     The invention has been described with reference to the preferred embodiment. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims and their equivalents.