Abstract:
An apparatus and method improve sight. The apparatus includes a first sight configured to view a scene. A second sight is configured to alter content representative of the scene in a first manner to form first altered content. A third sight is configured to alter content representative of the scene in a second manner to form second altered content. An image combiner is configured to combine the second altered content with the first altered content to form combined altered scene content.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present patent application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/401,836 entitled “System and Method for Multi-Spectral Clip-On Architecture” filed on Aug. 19, 2010, which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present application relates generally to optical systems and, more specifically, to an apparatus and method for multi-spectral clip-on architecture. 
     BACKGROUND 
     Often, it is desirable to enhance normal vision when viewing images/objects. In the weapons industry, weapons generally include viewing enhancements such as, for example, a rifle sight, a telescope, a video camera or other optical viewing system. These enhancements typically augment normal vision and improve performance. 
     However, in different conditions the performance of certain enhancements may be less than desirable. For example, different enhancements designed for use during the day may perform poorly at night time or in other degraded lighting environments. 
     Accordingly, there is a need for an apparatus and method that improves viewing in poor visible viewing conditions. In particular, there is a need for an apparatus and method for enhancing viewing through optical systems. 
     SUMMARY 
     In one exemplary embodiment an apparatus for improving sight is provided. The apparatus includes a first sight configured to view a scene. A second sight is configured to alter content representative of the scene in a first manner to form first altered content. A third sight is configured to alter content representative of the scene in a second manner to form second altered content. An image combiner is configured to combine the second altered content with the first altered content to form combined altered scene content. 
     In another exemplary embodiment, an apparatus for improving sight is provided. The apparatus includes a first sight configured to view a scene. A mount is positioned along a path between the first sight and the scene. A second sight is adapted to be mounted onto the mount. The second sight is configured to alter content representative of the scene to form altered content and display the altered scene content via the first sight. 
     In another exemplary embodiment, a method for improving a view of a scene at a first sight is provided. Content representative of the scene is altered in a first manner using a second sight to form first altered content. Content representative of the scene is altered in a second manner using a third sight to form second altered content. The second altered content is combined with the first altered content to form combined altered scene content. The combined altered scene content is displayed and viewable through the first sight. 
     Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of this disclosure and its features, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a block diagram of a multi-spectral optical system according to the present disclosure; 
         FIG. 2  illustrates an example configuration for a multi-spectral optical system according to the present disclosure; and 
         FIG. 3  illustrates another example configuration for a multi-spectral optical system according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure describes a system and method for a multi-spectral architecture that augments a day weapon sight with multiple sensor-augmented channels for use in night time, degraded, or other conditions that favor the use of selected sensors. While the added image sensors may be referred to herein as “night time image sensors” or “night time sensors,” or “infrared sensors” it will be understood that such sensors may be used during the day time and/or under other lighting conditions as well. 
       FIG. 1  illustrates a block diagram of a multi-spectral optical system  100  according to the present disclosure. Optical system  100  includes a first sight  104 , a second sight  106 , a third sight  108  and an image combiner  110 . 
     In this illustrative example, a user  102  employs the first sight  104  to view a scene  112 . In one embodiment, the first sight  104  is a day sight for viewing objects in the scene  112 . The first sight  104  may be an optical system that provides the user  102  with a magnified view of the scene  112  in the spectrum of visible wavelengths. As will be appreciated, in one application, the first sight  104  is attached to a weapon  114  and used to target the weapon  114 . In another application, the first sight  104  may be used for surveillance or other viewing purposes. 
     In environmental conditions that degrade or prevent viewing of the scene  112 , the user  102  may introduce and use the second sight  106 . The second sight  106  typically provides a sensor-augmented view of the scene  112 , at unity magnification, and substantially without deviation of the apparent angle to the scene  112  as compared to the apparent angle without the second sight  106  installed. For example, during nighttime, the user  102  may add a second sight  106  as a night scope to see objects in the scene  112 . The second sight  106  may be referred to as a “clip-on” sight because it is configured structurally to clip/attach/mount onto and off a mounting base  116  on the weapon  114 . The mounting base  116  is a surface on which attachments may be mounted to the weapon  114  (e.g. mounting rail). 
     In one embodiment, the second sight  106  captures an image of the scene  112  in a different waveband, converts the scene content into a visible waveband and displays the converted scene content to the user  102  via the first sight  104 . In another embodiment, the second sight  106  may function as an image intensifier. For example, second sight  106  captures an image of the scene  112  in visible and/or near-visible wavelengths then generates and displays an intensified or amplified image to the user  102 . 
     In some embodiments, the second sight  106  includes functionality to display the converted or intensified scene content in a characteristic color (or colors). The use of color may simplify the ability of the user  102  to recognize the operating waveband used by the second sight  106  (or distinguish the image generated by the second sight  106  from the image generated by the first sight  104 ). 
     In given applications, the user  102  may also want to observe the scene  112  in a waveband different than that used by the second sight  106 . Viewing the scene  112  in two wavebands may reveal information about the scene  112  that is not discernable by viewing only a single waveband. In such embodiments, a third sight  108  is included in the system. Similar to the second sight  106 , the third sight  108  functions to provide a sensor-augmented view of the scene  112 , at unity magnification, and substantially without deviation of the apparent angle to the scene  112 . In another embodiment, the third sight  108  could electronically or optically magnify the scene  112  for surveillance operations. 
     To enable viewing of the images generated by both the second sight  106  and the third sight  108 , optical system  100  includes an image combiner  110 . Image combiner  110  receives the images generated by the second and third sights  106 ,  108  and combines them into a composite or combined image enabling the user  102  to view the combined images via the first sight  104 . In one example, the image combiner  110  optically superimposes the image output from the third sight  108  onto the image output from the second sight  106 . 
     Examples of the image combiner  110  may include a fold mirror or coated prism that partially intrudes into the field of view from the side, or a center mounted fold mirror or prism. In one example, the image combiner  110  is a scene injection device. Examples of scene injection devices are described in U.S. Pat. Nos. 7,483,213 and 7,554,740, assigned to the assignee of the present disclosure, and which are incorporated herein by reference. 
     As previously described, the third sight  108  may display converted or intensified image/scene content in a characteristic color (or colors) different from a characteristic color used by the second sight  106 . In this way, the user  102  can distinguish scene waveband content produced by the third sight  108  from that produced by the second sight  106 . Other modes of enhancement, such as, for example, edge enhancement or object outlining, could be used in combination with or instead of color difference(s). These other modes of enhancement may assist the user in distinguishing between the separate images of a combined image, and may help to limit the reduction in overall contrast that may occur when two independent images are superimposed. 
     The illustration of the optical system  100  is not intended to imply any particular physical or architectural limitations in which different embodiments may be implemented. Other components in addition to and/or in place of the ones illustrated may be used. Some components may be unnecessary in some embodiments. Also, the blocks are presented to illustrate some functional components. One or more of these blocks may be combined and/or divided into different blocks when implemented in different embodiments. 
       FIG. 2  illustrates an example configuration for a multi-spectral optical system  200  according to the present disclosure. In this illustrative example, the optical system  200  includes a first sight  204 , a lower sight  206  and an upper sight  208 . 
     The lower sight  206  generates a sensor-augmented image of a scene and is mounted or attached (e.g. clip-on) to a mounting base (not shown in  FIG. 2 , e.g. mounting base  116  in  FIG. 1 ). The lower sight  206  provides this view at unity magnification and without deviation of the apparent angle to the target that would appear without the lower sight  206  installed. Sight  206  is also referred to as “inline” because its line of sight is in line with the optical axis of the sight  204 . In various embodiments, the lower sight  206  includes one or more nighttime sensors enabling the generation of the sensor-augmented image. In another embodiment, the lower sight  206  is a thermal inline sight or an image intensified inline sight. In still another embodiment, the lower sight  206  may be a TANS® intensified night sight, manufactured by OmniTech Partners, Inc. 
     In the embodiment shown in  FIG. 2 , the system  200  includes the upper sight  208  that is mounted to the lower sight  206  and/or the mounting base (not shown, e.g. mounting base  116  in  FIG. 1 ). The upper sight  208  includes one or more night time image sensors which may be the same, similar or different type than those embodied within the lower sight  206 . 
     The upper sight  208  includes input optics in a sensor  212  to form an image output display with output optics  210 . A portion of the output optics  210  is disposed or positioned between the lower sight  206  and the first sight  204 . One embodiment of the upper sight  208  may include an optical image generator and injector as described in U.S. Pat. No. 7,554,740, while other embodiments may utilize any other suitable beam combining optics or scene injector. The upper sight  208  also provides unity magnification and is internally optically aligned so that the apparent angle of its output image is essentially the same as the line of sight of its input image. The mechanical alignment between lower sight  206  and upper sight  208  may not be critical to provide the user  202  with an unaltered line of sight originating from either lower sight  206  or upper sight  208 . 
     With only the lower sight  206  installed, the user  202  observes the image output produced by the lower sight  206  through the first sight  204 . When the upper sight  208  is added and installed, the user  202  observes the image output from the upper sight  208  as optically superimposed upon (or combined with) the image output of the lower sight  206 . This combined image provides the user  202  with a multiple sensor view of the scene. Utilization of multiple sensor views provides an enhanced view of the scene and results in improved targeting and viewing. Both the lower sight  206  and the upper sight  208  are substantially insensitive to alignment problems with respect to the first sight  204  because each includes unity magnification and does not vary the apparent angle from the user  202  to an object in the scene. 
     In one embodiment, the upper sight  208  may be configured to mechanically interface (e.g., attach, mount) with the lower sight  206 , and the upper sight  208  may be attached or detached from the lower sight  206  as desired needed. In another embodiment, the upper sight  208  is configured to mechanically interface with a mounting base/rail or other surface (e.g. mounting base  116  in  FIG. 1 ) of a weapon (e.g. weapon  114  in  FIG. 1  or other underlying support structure) to which the first sight  204  and the lower sight  206  are also interfaced/mounted. In another embodiment, the upper sight  208  may be configured to mechanically interface with both the lower sight  206  and mounting base/rail or other surface. 
     In the embodiment shown in  FIG. 2 , at least a portion of the upper sight  208  (e.g., the input optics  212 ) is disposed or positioned directly above the lower sight  206 . In a different embodiment, the relative position or orientation of the upper sight  208  with respect to the lower sight  206  may be changed (e.g., the upper sight  208  is no longer directly above the lower sight  208 , such as along its side). In such embodiments, the centerline (or optical axis) of the upper sight  208  may be left or right of the centerline (or optical axis) of the lower sight  206  and the centerline (or optical axis) of the first sight  204 . Accordingly, the upper sight  208  may be in any other relative position with respect to the first sight  204  provided it is able to function as described and intended herein. For example, the optical centerlines of the lower sight  206  and the upper sight  208  may be close enough to parallel to allow outputs of the lower sight  206  and the upper sight  208  to partially overlap. 
     However, it should be understood that neither absolute parallelism or a static orientation between the mechanical axes of lower sight  206  and the upper sight  208  may be required for proper operation, since the apparent angle from the location of the user  202  to a point in the scene is undeviated by either the lower sight  206  and the upper sight  208 . This behavior may be the result of the unity magnification and input to output optical axis alignment of lower sight  206  and upper sight  208 . For example, because lower sight  206  and upper sight  208  may not independently alter their independent lines of sight, when combined the resultant combined line of sight is also unaltered. Similarly, the mechanical axes of the lower sight  206  and the upper sight  208  do not need to be parallel with respect to the optical axis of the first sight  204 . For example, both upper sight  208  and lower sight  206  have a look-through line of sight that is optically independent from the mechanical axis of either sight. For example, each input ray is parallel to each resultant output ray. 
     In these examples, the lower sight  206  is fully independent from the upper sight  208 , and the lower sight  206  may operate without the upper sight  208  attached. Similarly, the upper sight  208  is independent from the lower sight  206  and may operate without the lower sight  206 . 
     In further embodiments, the upper sight  208  and the output optics  210  may be mounted in a common housing and attached and detached together as a single unit. Additionally, the output optics  210  and the upper sight  208  may be separate, and may be separately mounted to the lower sight  206  and/or underlying support. In such embodiment, the upper sight  208  may be removed with the output optics  210  remaining installed to enable status indications or other visible messages generated by the output optics  210  to be injected into the image generated and output from the lower sight  206  (being viewed through the first sight  204 ). 
       FIG. 3  illustrates another example configuration for a multi-spectral optical system according to the present disclosure. In the example configuration for the optical system  200  illustrated in  FIG. 2 , the upper sight  208  is mounted to the lower sight  206 . In the example configuration for the optical system  200   a  in  FIG. 3 , a mounting structure  304  is provided for mounting the upper sight  208  in the absence of the lower sight  206 . In this example, the mounting structure  304  is a mechanical substitute for the lower sight  206 . 
     This configuration has the benefit that a user may not desire to utilize both the lower sight  206  and the upper sight  208  but desires to utilize the capabilities or features provided by the upper sight  208 . This configuration allows use of the upper sight  208  in a “look-through configuration” with the first sight  204  alone. 
     Light  302  from an image/scene passes through (or alongside) the mounting structure  304  to the output optics  210  for combining with the image from the upper sight  208  for viewing through the first sight  204 . In one application, this configuration could provide a look through visible scene blended with a thermal scene. 
     In another embodiment, the mounting structure  304  may include an optical filter  306 . For example, without limitation, the filter  306  may be a partial blocking filter, color filter, complete blocking filter or other filter suitable for enhancing the thermal overlay scene. The filter  306  can be selected by the user for a particular environmental situation, and may include adjustability for transmission/color allowing the user to adjust the characteristics of the directly viewed scene to complement the image/scene as output through the upper sight  208 . 
     While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.