Patent Publication Number: US-2012033195-A1

Title: Multipurpose Aiming Sight with Head-Up Display Module

Description:
BACKGROUND 
     1. Field 
     Embodiments of the present disclosure relate to a multipurpose aiming sight with a head-up display module. 
     2. Background Art 
     Conventional aiming sights superimpose the image of an aiming reticle over a magnified or unmagnified scene. In a 1× (unmagnified) reflex sight, the aiming reticle may be superimposed on the direct view scene. With a magnified riflescope, a reticle may be placed over the magnified image formed by the objective lens and viewed through an eyepiece. 
     For a reflex sight, the projection of the aiming reticle is generally achieved with a reflective collimator. See U.S. Pat. Nos. 4,346,995 and 5,189,555, for example. Such a collimator can provide very good collimation for a small aiming reticle such as a small dot provided by a light emitting diode (LED). However, it generally cannot be used to project a large reticle pattern or an image scene because of off-axis aberration. 
     Prior art sights may use a long eye relief eyepiece and a beam combiner to provide a thermal image displayed over a direct view image. See U.S. Pat. No. 7,319,557, for example. While suitable for some applications, this arrangement limits the field of view of the system for a given exit aperture. 
     A wide field of view head-up display may be provided by using a curved beam combiner with optical power. See U.S. Pat. Nos. 5,268,696 and 6,392,812, for example. However, a curved beam combiner generally results in distortion of the direct view image, particularly in a fast compact optical system. 
     Moreover, any asymmetry in the X and Y directions requires complicated asymmetric projection optics to minimize the aberration and distortion in the projected image. 
     For some military and law enforcement applications, weapons are provided with either a 1× reflex sight for close quarter combat and/or a magnified riflescope for long range target engagement. In one approach, a mini reflex sight is mounted on top of a rifle scope so that both are available as needed. However, this requires one to move his head to a different position to use either scope and to change his cheek weld, i.e. the position of the weapon stock against the cheek. Another approach includes 1× reflex sight with a magnified rifle scope mounted behind that can be flipped in and out of aiming position as needed. However, the mechanism that flips the rifle scope in and out of position is vulnerable to damage. In addition, the balance of the weapon is affected by the change in position of the rifle scope as it is not symmetrically positioned about the center of gravity. Another approach uses a variable power 16×-4× rifle scope. The scope is set at 1× for close quarter combat/battle (CQB) with magnification provided as needed for longer range engagements. However, a variable power rifle scope at 1× does not have the virtually unlimited eye relief or distortion free direct view of a reflex sight. Moreover, the view seen by one eye through the scope and the direct view seen by the other eye are not registered, making it difficult to shoot with both eyes opened. 
     SUMMARY 
     A multipurpose sighting device includes a viewing window, an illuminated display, a beam combiner positioned to transmit light from a target scene and reflect light from the illuminated display through the viewing window, and projection optics that project an image of the display through the viewing window at a distance to be in focus with the target scene. 
     A method for sighting a target in a target scene includes imaging light from the target scene onto a detector array, generating an image including an aiming reticle on an illuminated display, projecting the image from the illuminated display through a viewing window, and combining the image from the illuminated display with a direct view of the target scene when a direct view window is open and generating an image of the target scene from the detector array with the aiming reticle superimposed on the illuminated display when the direct view window is blocked. 
     The present disclosure includes embodiments having various advantages. For example, various embodiments provide a multipurpose sight combining a wide field-of-view 1× (direct view) reflex sight with a magnified electronic rifle scope. The sighting device does not require a change in head position to switch between the 1× reflex sight and the electronically generated view. There is no change in center of gravity or balance when using either mode of operation. The use of flat optics for the direct view operation provides an undistorted image of the target scene facilitating target acquisition and environment awareness with both eyes opened. 
     The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present disclosure described herein are recited with particularity in the appended claims. However, other features will become more apparent, and the embodiments may be best understood by referring to the following detailed description in conjunction with the accompanying drawings, in which: 
         FIG. 1  shows a ray tracing diagram illustrating operation of a sighting device/method according to embodiments of the present disclosure; 
         FIG. 2  illustrates a representative narrowband or monochromatic embodiment of a multipurpose sighting device according to the present disclosure; 
         FIG. 3  illustrates a representative full-color embodiment of a multipurpose sighting device according to the present disclosure; 
         FIG. 4  is a block diagram illustrating operation of a device/method for sighting according to various embodiments of the present disclosure; and 
         FIG. 5  is illustrates operation of a device/method for sighting according to various embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the Figures may be combined with features illustrated in one or more other Figures to produce embodiments that are may not be explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. The representative embodiments used in the illustrations relate generally to a sighting device that may be used in a direct view mode or an electronically imaged mode that may provide an enhanced and/or magnified image and aiming reticle. Those of ordinary skill in the art may recognize similar applications or implementations not specifically described. 
       FIG. 1  is a ray tracing diagram illustrating design and operation of a head-up display module that may be used in a sighting device or method according to embodiments of the present disclosure. Device  100  includes an illuminated display  112  having a plurality of individually controlled pixels arranged in an array. Display  112  is in communication with an associated processor or controller  460  ( FIG. 4 ) and may be used to display images and digital data. In one embodiment, display  112  is implemented by a transmissive liquid crystal display illuminated by a narrowband source. For example, a micro LCD display (e.g. model LV640M manufactured by Kopin Corporation of Westboro, Mass.), which is illuminated by one or more LEDs emitting substantially monochromatic light or a narrow band of light (e.g. 20 nm band of light) with a center or peak wavelength of about 620 nm may be used. Of course other types of monochrome or color displays may be used depending on the particular application and implementation. Similarly, the center or peak wavelength and bandwidth or range of wavelengths may be selected to suit particular applications to provide a particular color of graphic information and/or aiming reticle while allowing other wavelengths to be substantially transmitted such that the direct view is not significantly different from the view seen by the other eye to facilitate sighting with both eyes opened. 
     The image displayed on illuminated display  112  can be a digitally generated graphic, such as an aiming reticle, target range information, GPS information, etc. based on internal information or external information provided via a wired or wireless data port. Display  112  may also generate an image from an internal or external imaging sensor such as a CCD detector array (e.g. SONY XCL-X700) or a micro bolometer focal plane array (e.g. L-3 Infrared Products Series 17 FPA) as illustrated and described in greater detail with reference to  FIGS. 2-5 . 
     As also illustrated in  FIG. 1 , projection optics  114  include a plurality of optical elements  116 ,  118 , and  120  with a folding mirror  122  disposed between two of the optical elements  118 ,  120  in this embodiment. Projection optics  114  project an image of display through a viewing window  126  at a distance to be in focus with the target scene. In the embodiments represented by  FIG. 1 , projection optics  114  is implemented by three (3) lenses  116 ,  118 , and  120  with folding mirror  122  disposed between lenses  118  and  120  to provide a more compact arrangement. Projection optics  114  and folding mirror  122  project the image of illuminated display  112  using a beam combiner  124  through viewing window  126  a far distance so the image is at the same focus as the distant target scene. In this embodiment, folding mirror  122  is positioned at 45 degrees between lens  118  and lens  120  to change the optical path from horizontal to vertical and direct light from illuminated display  112  upward, which is then reflected by beam combiner  124  back to a horizontal path to exit viewing window  126 . 
     As described in greater detail herein, beam combiner  124  may be implemented by a spectrally selective beam combiner in some embodiments or alternatively a generally broad band beam combiner in other embodiments depending on the particular application and implementation. A spectrally selective beam combiner may be implemented by a rugate-type beam combiner or a holographic beam combiner, for example. As known, a rugate type beam combiner uses multiple coating layers of differing refractive indices while a holographic beam combiner uses an interference pattern recorded in a thin layer of material such as dichromated gelatin, silver halide emulsion, or photopolymer in the form of refractive index variations. An broad band beam combiner may be provided by a partially silvered mirror, for example. When implemented by a spectrally selective beam combiner, beam combiner  124  has a peak reflectivity at a wavelength that may be selected to substantially match the peak or center emission wavelength of the illumination source of display  112 , such as 620 nm for example. The bandwidth or range of wavelengths reflected by the beam combiner may also be of a similar range as the illumination source for optimum light utilization. 
     Spectrally selective embodiments of beam combiner  124  transmit light at wavelengths outside of the selected reflective wavelength range or band. 
     In one embodiment having an appropriately matched beam combiner  124  and display  112 , up to 90% of light from display  112  is reflected by beam combiner  124  and directed toward viewing window  126  while up to 90% of light  130  from the target scene, which generally includes a full spectrum of wavelengths outside of the reflected wavelength(s), is transmitted through beam combiner  124  to be combined with the reflected light seen by the user. System  100  provides a wide field of view and long eye relief for situational awareness with an exit pupil  128  at a predetermined distance from viewing window  126 . 
     A head-up display module as illustrated in  FIG. 1  may be used in a number of applications, such as a multipurpose sighting/aiming device illustrated in the embodiment shown in  FIG. 2 . Components illustrated in the embodiments of  FIGS. 2-5  having similar structure and/or function to those illustrated in  FIG. 1  are designated with similar reference numerals. 
     Sighting device  200  includes a housing  202  having a target scene direct view aperture/window  234  and a target scene detector aperture  204  for receiving light  230  from a target scene. As will be appreciated by those of ordinary skill in the art, as used herein “light” is not limited to visible light and may include a wide range of the electromagnetic spectrum depending on the particular application. In the representative embodiment illustrated in  FIG. 2 , an objective lens  242  is disposed within housing  202  in front of detector aperture  204  and is used in combination with a fixed or variable iris  246  to focus energy radiated from the target scene onto a sensor or detector array  240 . In one embodiment, objective lens  242  is positioned to image a target scene on the detector array. Depending on the particular application and implementation, objective lens  242  may provide fixed or variable magnification (optical power), which may be further digitally enhanced or magnified. Likewise, although illustrated as a single lens, a multiple-element optic may be used to provide magnification or other image enhancement. 
     Detector array  240  disposed within housing  202  is connected to a controller  460  ( FIG. 4 ) that may be implemented by a dedicated microcontroller or by a programmable microprocessor-based controller, for example. Images or other information collected by detector array  240  may be processed by the controller and used to control the image displayed and the position of the image on illuminated display  212  as described in greater detail herein. In the representative embodiment illustrated in  FIG. 2 , display  212  is a transmissive substantially monochromatic LCD display having an array of individually controllable pixels and is backlit by a narrowband LED source emitting light centered about 620 nm with a range of about 20 nm, i.e. light of wavelengths between about 610-630 nm, which generally appears amber or orange to the user. Of course, various other types of displays may be used for particular applications. 
     Projection optics implemented by lenses  216 ,  218 , and  220  are disposed within housing  202  and include a folding minor  222  disposed between two of the three lenses, which are lenses  218  and  220  in this embodiment. The projection optics project an image of illuminated display  212  to spectrally selective beam combiner  224 . Beam combiner  224  has a peak reflectivity wavelength to match the center wavelength of display  212  so that most light having a wavelength around the peak reflectivity wavelength exiting lens  220  is reflected by beam combiner  240 , and most light  230  from the target scene passing through direct view aperture  234  is transmitted through beam combiner  224 , except for the narrow band of light near the peak wavelength, which is about 620 nm in one embodiment. The combined light from the target scene and the image of illuminated display  212  then passes through viewing window  226  for viewing by a user. As those of ordinary skill in the art will recognize, practical optical devices are generally not 100% efficient. As such, references to light being transmitted or reflected by a device do not imply that all incident light is transmitted or reflected. 
     Various embodiments of a sighting device according to the present disclosure have a housing  202  that is hermetically sealed with an internal atmosphere of nitrogen to eliminate contaminants as well as condensation or fogging. As such, housing  202  is sealed by objective lens  242  and generally transparent viewing window  226  and target scene window  234 . Various windows and lenses may also be coated to provide desired characteristics. For example, anti-reflective (AR) coatings or glare reducing coatings may be applied to one or more surfaces of various components. As used herein, a “window” may refer to an opening or aperture that allows light to enter or exit the device, or may imply a generally transparent physical barrier. 
     As also shown in  FIG. 2 , sighting device  200  may include a shutter  232  positioned to selectively block light from direct view aperture/window  234 . As such, shutter  232  blocks light from the target scene from being transmitted through beam combiner  224  and viewing window  226 . In this embodiment, shutter  232  is implemented by a manually operable opaque cover that can be moved as indicated at  236  between a first position (shown in solid) with the direct view window  234  open, and a second position (shown in dashed line) where the direct view window  234  is blocked. A sensor or switch  248  may be provided to detect when shutter  232  is closed. Switch/sensor  248  may detect actual position of shutter  232 , or may be activated when shutter  232  is in a closed position or open position, for example. Of course, switch/sensor  248  may be disposed in a different position than illustrated to detect the actual position or open position of shutter  232 . Shutter  232  may be implemented by a hinged cover as illustrated, or by another type of electrically actuated manually controlled shutter or automatically controlled mechanical shutter, such as a louvered shutter, multi-blade iris, etc. 
     Alternatively, an electronically controlled optical shutter may be provided, such as an LCD shutter, for example, in communication with a controller  460  ( FIG. 4 ) as described in greater detail herein. When implemented by an electronic shutter, the shutter may be a separate component positioned behind direct view window  234 , or may be function as direct view window  234  depending on the particular implementation. 
     When used in a direct viewing mode as a 1× reflex or close combat sight, a user looking through viewing window  226  with shutter  232  open will have a direct view through beam combiner  224  and window  234  of the target scene as well as an image of illuminated display  212  reflected by beam combiner  224 . With shutter  232  in the open position, illuminated display  212  displays an orange on black aiming reticle. The operator then sees the orange color aiming reticle which is projected out to a distance over the target scene to be in focus with the target scene. To change the elevation and/or azimuth position of the reticle to zero the sight, the reticle image can be shifted laterally in the X-Y positions on display  212  such that a point of aim coincides with the point of impact of the projectile fired by an associated weapon. Because the reticle is digitally generated, the type of reticle or reticle pattern can be easily changed if desired and is user selectable in various embodiments according to the present disclosure. In one embodiment, reticle position is automatically adjusted on display  212  in response to target distance or range of a selected target in the target scene to compensate for ballistic trajectory. 
     In addition to the image of a reticle, display  212  may also display digital data, which may be obtained from embedded and/or external sensors, such as a laser range finder, an electronic compass, a bolometer, and/or a global positioning system, for example. Display  212  may also display an image or information processed from an image of the target scene captured by detector array  240 . 
     In a magnified rifle scope mode of operation, shutter  232  is closed as indicated at  236  to cover the front of direct view window  234  and block light  230  from entering direct view window  234 . For embodiments having a manually actuated shutter/cover  232  and switch/sensor  248 , the switch/sensor is activated when shutter  232  is closed to signal the corresponding controller  460  ( FIG. 4 ) and/or associated electronics to change from displaying a reticle to displaying an image from detector array  240  with a digital reticle superimposed on, or composited with the image. As previously described, the position of the digital reticle can be shifted to match the point of impact of the bullet fired by an associated weapon. In one embodiment, the position of the digital reticle may be dynamically adjusted in response to sensor data, such as a range finder, for example. The image captured by detector array  240  may be processed to enhance the image and/or digitally magnify the image before being displayed by display  212 . Similarly, imaging lens  242  that forms the image on detector array  240  may be implemented by a fixed objective lens, or by a zoom lens to provide optical zoom/magnification in addition to, or in place of, various digital image processing. 
     As previously described, illuminated display  212  may be implemented by a monochromic display, with detector array  240  implemented by a black and white imaging detector used with a spectrally selective beam combiner  224 . In an alternative embodiment, a full color image may be provided using a color imaging sensor/detector  240 , such as a Hitachi HV-FF2F color CCD imaging sensor, in combination with a polychromatic or color illuminated display  212 , such as a Kopin XGA LVC micro LCD display. In this embodiment, the narrow spectral band beam combiner  224  can be replaced by a broadband beam combiner, which may be implemented by a partially silvered minor, for example. However, the reticle brightness and optical transmission will be reduced. For example, using a 30% reflective/70% transmissive ( 30 R/ 70 T) partially silvered beam combiner  224  would result in only 30% of the light from display  212  being reflected by beam combiner  224  through viewing window  226  and only 70% of light  230  entering direct view window  234  from the target scene being transmitted through beam combiner  224  and viewing window  226  to the user. 
     Another embodiment of a sighting device incorporating a head-up display module according to the present disclosure is illustrated in  FIG. 3 . Sighting device  300  includes a color illuminated display  312  and a color imaging sensor  340  with a spectrally selective beam combiner  324 . Similar to the embodiment of  FIG. 2 , a fixed or variable objective lens  342  and fixed or variable iris  346  are used to image light  330  from a target scene onto color detector array  340 , which is in communication with associated electronics ( FIG. 4 ) to provide corresponding digital data to color illuminated display  312 . Projection optics formed by lenses  316 ,  318 , and  322  in combination with a first achromatic folding minor  322  project an image of display  312 , which is partially reflected by beam combiner  324 . In this embodiment, color display  312  is programmed to display an aiming reticle and any other information in the color that matches the spectral reflectivity of beam combiner  324  when operating in the direct view or 1× reflex mode. Beam combiner  324  reflects a majority of this light and in some embodiments up to 90% of light at the selected wavelengths while transmitting light of wavelengths outside of the narrow band as previously described. 
     Target scene light  330  enters through target window  334  and a majority of the light outside of the narrowband wavelengths of beam combiner  324  passes through beam combiner  324  and viewing window  326  to provide a direct view mode with an aiming reticle and/or other information projected to a distance to be in focus with the direct view scene as previously described. In some embodiments, up to 90% of the light  330  will pass through beam combiner  324  and viewing window  326 . A second folding minor  338  disposed on the target scene side of beam combiner  324  is positionable between a first position parallel to beam combiner  324  to block light  330  from the target scene and reflect light from folding minor  322  passing through beam combiner  324  to viewing window  326 , and a second position (dashed line) allowing light from the target scene to pass through beam combiner  234  and viewing window  326 . 
     When in the 1× close combat sight mode, second folding mirror  338  stays in the up position (dashed line) activating switch/sensor  350 . Sighting device  300  operates as previously described with 90% of the narrow band light from display  312  forming an image of the reticle and/or any other superimposed information directed through viewing window  326  toward the user. This light is combined with the approximately 90% of light  330  (wavelengths outside the spectral band of the beam combiner) from the target scene that passes through beam combiner  324  and viewing window  326 . 
     Mirror  338  is moved to the first position parallel to beam combiner  324  when device  300  is switched into the digital imaging mode, which may be used to provide a magnified electronic riflescope, for example. When moved down into the first position, minor  338  automatically blocks the outside view performing the function of shutter  232  as described with respect to the embodiment of  FIG. 2 . Depending on the particular implementation, minor  338  may be manually actuated with an associated switch (not shown) used to detect mirror position. Alternatively, mirror  338  may be electronically controlled by an associated controller ( 460 ,  FIG. 4 ). In either case, moving mirror  338  into the first or down position automatically switches the mode of display  312  to display the image from detector array  340  in addition to any other superimposed data or graphics, such as the aiming reticle, target distance, etc. All wavelengths of light that are not reflected by narrow band beam combiner  324  pass through the beam combiner and are reflected by second folding mirror  338  at the same angle as those wavelengths reflected by beam combiner  324 . Provided that beam combiner  324  and second folding minor  338  are parallel to each other, the images reflected by the beam combiner and the mirror are registered and nearly all the light from display  312  is directed through viewing window  326  to the user, presenting a full color image of the target scene with any additional information, such as an aiming reticle, target range, thermal image, GPS information, temperature, etc. digitally superimposed. As such, the arrangement illustrated in the representative embodiment of  FIG. 3  maintains high see through transmission in the 1× close combat sight mode and high image brightness in both the direct view 1× close combat sight mode and the digital image mode. 
       FIG. 4  is a block diagram illustrating a system or method for sighting a target in a target scene using a head-up display module according to embodiments of the present disclosure. Those of ordinary skill in the art will recognize that various functions and devices represented in  FIG. 4  are optional and depend on the particular application and implementation. Various embodiments may incorporate different combinations of devices/functions illustrated and any of the functions or components illustrated are not necessarily required for an operable embodiment. Controller  460  controls illuminated display  412  to selectively display a selected aiming reticle and/or other digital information based on the current operating mode and/or user selected information. For example, depending on the particular application and implementation, controller  460  may be implemented by a dedicated microcontroller or ASIC in combination with associated electronics to drive display  412 . In some embodiments, controller  460  is implemented by a programmable microprocessor based controller. As such, in some embodiments, the reticle may be selected by a user with associated input keys or switches, such as mode select switch  464 , for example. Other embodiments may display only a single reticle selected during manufacturing or factory programming of the associated controller, or assembly using a particular ASIC or microcontroller, for example. 
     Controller  460  receives signals or data from detector array  440 , which may be a black/white or color imaging detector, for example. The image may be processed by controller  460  using selected image processing algorithms  470  that may be used to provide image enhancement, target identification, digital magnification, etc. Controller  460  generates appropriate signals to control display  412  to display information and/or an image from detector array  440  depending on the operating mode. As previously described, the operating mode may be selected by a mode select input  464 , or may be determined by manual operation of shutter  434  as detected by an associated switch/sensor  448  so that the mode switches to automatically display an image detected by detector array  440  when shutter  434  is closed. In some embodiments, shutter  434  may be manually operated by the user. Other embodiments include an electrically operated mechanical shutter or LCD shutter that is operated by controller  460  to change operating modes. Similarly, in embodiments having a second folding mirror  438 , manual positioning of folding mirror  438  may be detected by an associated switch/sensor  450  to change operating modes from direct view to digitally imaged mode. Some embodiments have position of second folding mirror  438  controlled by controller  460  using an associated actuator. Similarly, various embodiments may include a controllable zoom lens  452  and/or adjustable iris  454  in communication with controller  460 . 
     Controller may include a data input port to receive images/data from an external device/sensor  480 . The received image/data can be processed by controller  460  and incorporated or superimposed with data from embedded sensors or detector array  440  to produce a composited image for display  412 . Representative external devices/sensors may include a range finder  482 , a bolometer thermal detector array  484 , GPS, and/or position/bearing information  486 , for example. External devices  480  may communicate via a wireless or wired connection through an associated data port of controller  460  to provide digital or analog information for controller  460  to incorporate into an image generated by display  412 . 
     Controller  460  may include volatile and persistent memory for storing data and instructions used for image processing  470 , ballistic trajectory compensation  472 , and various other functions or features. In addition, inputs may be provided for azimuth and elevation adjustments  468  of the image position to center it with the direct view and azimuth and elevation adjustments  462  to zero the sighting device for a particular target range. Azimuth/elevation adjustments  462  of the reticle are made electronically by controller  460  in response to user input to shift or adjust the position of the aiming reticle displayed on display  412 . In some embodiments, trajectory compensation for ammunition may be provided based on distance or range of a selected target or other environmental information and the type of ammunition being fired by an associated weapon. Target information may be provided by a range finder  482  or input by the user, for example. Trajectory compensation may be provided by automatically adjusting or shifting position of a reticle in the image displayed by display  412  relative to the previous zero position of the reticle. For example, longer range targets may result in the reticle being shifted down or lowered from its zero position in the image displayed by display  412  so that the weapon muzzle is pointed higher when the user aligns the reticle with the target to compensate for the corresponding bullet drop at the target range. Similarly, for targets at a distance closer than the distance where the sighting device was zeroed, the reticle may be shifted up or raised relative to its zero position. 
       FIG. 5  is a block diagram illustrating operation of a system or method for sighting a target in a target scene according to various embodiments of the present disclosure. As described previously with respect to  FIG. 4 , various functions illustrated in  FIG. 5  are optional or not included in some embodiments depending on the particular implementation. Similarly, various functions may be performed by a controller or control logic implemented by hardware and software, while other functions are performed by optical elements and/or combinations of optical devices. The functions illustrated may be repeatedly performed although not explicitly illustrated. Similarly, some functions may be performed simultaneously, in a different order than shown, or may be omitted. 
     In one embodiment, a method for sighting a target in a target scene includes imaging light from the target scene onto a sensor or detector array as generally represented by block  500 . The image from the detector or sensor array may be processed as represented by block  502  and used to generate an image on an illuminated display as represented by block  506  when operating in an electronic rifle scope mode. When operating in direct view or close combat mode, data from the imaging sensor array is not required and is generally not used to generate the image  506  on the illuminated display, which is implemented by an LCD display in one embodiment. 
     A stored reticle image  504  is generated on the illuminated display  506  and projected by projection optics  516  through a beam combiner  518  to an eye of the operator as generally represented by block  520 . The projected image from the illuminated display  506  may be combined with a direct view of a target scene as represented by block  522  when operating in a direct view or close combat view mode and an associated direct view shutter or window is open as represented by block  524 . Stored reticle image  504  may be incorporated into or composited with the processed image  502  from the sensor array when operating in the electronic rifle scope mode with the direct view blocked by a closed shutter or by a 2 nd  folding mirror in the down position, for example, as generally represented by block  524 . Projection optics  516  facilitate use of a stored reticle image  504  that is not aberration-limited to a dot, but may include larger and more complex combinations of geometric shapes, such as circles, polygons, lines, arcs, etc. that can be projected to be in focus with the direct view target scene. 
     As previously described, the operating mode may be changed between an electronic rifle scope mode and direct view or close combat view mode by activating a corresponding switch on the sighting device that communicates with a controller to control one or more electrically actuated mechanical, electromechanical, or electronic devices, such as a shutter and/or mirror positioning device. Alternatively, a shutter and/or mirror may be manually moved to a position to activate a particular operating mode. The controller may detect one or more switch inputs corresponding to shutter/mirror position and/or operator mode selection to control the image generated on the illuminated display as represented by block  506 . 
     As also shown in  FIG. 5 , block  502  represents processing the image from the imaging sensor array  502  for display on the illuminated display as represented by block  506 . The generated image may include digital enhancement and/or magnification of the image using various image processing algorithms to improve target acquisition, for example. Reticle position on the display may be adjusted as represented by block  508 . Adjustments may be made via corresponding inputs to shift the azimuth and elevation of the reticle to zero the sighting device. Alternatively, or in combination, repositioning of the reticle may be dynamically performed based on a trajectory calculation for a corresponding projectile using data from a laser range finder, GPS, compass, etc. as represented by block  510 . Similarly, the position of the sensor image may be adjusted relative to the display as represented by block  514 . Superposition or compositing of data from external sensors/devices, such as an external image sensor  512  may be performed to generate a combined image as represented by block  506 . 
     As such, the present disclosure provides embodiments of a head-up display module with a wide field of view and distortionless direct view image that may be used in a sighting device. Use of an embedded monochrome or color display facilitates superposition of images, graphics, and/or digital data from embedded or external sensors on the direct view scene, or on an electronically generated and composited image of the target scene. As such, embodiments of the device can be used as a 1× close combat sight similar to a red-dot or reflex sight, as a magnified electronic rifle scope, or as a direct view/thermal image fusion sight, for example. Use of an embedded imaging display in combination with embedded or external sensor data of various embodiments allows the position of an aiming reticle to be automatically adjusted on the display based on target or environmental information and superimposed on the direct view or electronically generated image of the target scene. 
     While one or more embodiments have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible embodiments within the scope of the claims. Rather, the words used in the specification are words of description rather than limitation, and various changes may be made without departing from the spirit and scope of the disclosure. While various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, as one skilled in the art is aware, one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes include, but are not limited to: cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. The embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications or implementations.