Abstract:
A stealth laser sighting system for a firearm includes a non-visible laser and night imaging device with display. The stealth laser sighting system combines all of the features required for stealth laser sighting within a self-contained accessory. The stealth laser sighting system provides for an optional visible laser system. and can include features such as electronic calibration, laser rangefinder compensation, target zoom, projected graphic laser marking, and windage and elevation adjustments on a graphical overlay. The stealth laser sighting system can be packaged as an accessory or all of the features can be integrated into a firearm.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Many people own small firearms, such as revolvers, pistols, and rifles for sport and for protection. The United States Constitution and state laws permit people to protect themselves. A person may use force, even deadly force, against another person when he/she reasonably believes that such force is immediately necessary for the purpose of protecting him/herself against the use of unlawful force by such other person. For a firearm to be used in this manner it needs to be quickly and accurately discharged or else it may provoke return fire and result in personal injury or even death. 
         [0002]    A very simplified process describing the discharge of a firearm, such as a handgun, is to load with ammunition, aim the gun at a target, and fire the gun by actuating a trigger. The most common means to aim a gun is the visual alignment of a target with front and rear mechanical sights typically located along the top barrel of the gun. While aiming, the top of the front sight should be level with the top of the rear sight and the front sight should be centered left/right within the horizontal opening of the rear sight. Accurate firing using mechanical sighting requires that the target location, front sight, and rear sight be carefully aligned on the optical axis of the shooters eye to achieve success. This is not a process that lends itself to rapid response in an emergency situation. Many times a gun will need to be discharged rapidly and is aimed in an intuitive process where the gun is pointed at the target without mechanical sighting and then discharged. The accuracy when firing in this manner is marginally effective at short distances and relatively ineffective at longer distances. 
         [0003]    The aiming accuracy problem has been addressed with the advent of the development of a laser sight. U.S. Pat. No. 5,179,235, entitled “Pistol Sighting Device”, issued Sep. 10, 1991 to Toole, and U.S. Pat. No. 4,934,086, entitled “Recoil Spring Guide Mounting for Laser Sight”, issued Jun. 19, 1990 to Houde-Walter, illustrate the utility of lasers for aiming firearms, such as guns and rifles. After a laser is calibrated to a firearm, a visible red laser dot shines on the target at the location that a bullet will strike when fired upon. The firearm can rapidly acquire a target and be fired from positions not requiring mechanical sighting. The laser system overcomes the aforementioned limitations for rapid firing and accuracy and provides a viable means to protect oneself with a firearm. It will be appreciated that laser sights are currently available as accessories for firearms and are available as factory integrated features on stock firearms. When purchased as an accessory there are a host of universal attachment methods known in the art to fasten the laser assembly to a firearm. Many firearms even come with accessory mounts built in. Sometimes the lasers are mounted below the firearm&#39;s barrel, sometimes above the firearms barrel, and sometimes along side the firearm&#39;s barrel. Additionally the calibration of the laser to the firearm needs to take into account basic targeting variables such as range (elevation) and windage. These adjustments are generally made with mechanical alignment set screws or thumb screws to position the laser to shine at the point of bullet impact and are also well known in the art. To assist in the calibration, range finders that calculate the distance from the firearm to a target are readily available. Some rangefinders are simple optical sights, some use sound waves, and some use modulated laser light. Laser sights require power that generally is provided by batteries, such as Alkaline or lithium batteries. Some laser sight models take into account power conservation and have a momentary push button activated by the thumb on the firearm&#39;s grip. Other laser sight models conserve power by pulsing the laser instead of simply leaving the laser on steady state. Most laser sights, however, just have on/off slide switches that steadily drain the batteries. 
         [0004]    One of the statistics that is important concerning use of firearms for protection is that over 80% of shootings happen in low light situations. Many accessories for firearms contain either a visible flashlight or an IR flashlight for night vision. The ability to aim in low light situations with a visible flashlight introduces another dangerous issue. While the visible light allows the shooter to aim effectively, it also creates a clear target for an intruder to aim back. To circumvent the risk of illuminating oneself as a target for your opponent, U.S. Pat. No. 5,584,137, entitled “Modular Laser Apparatus”, Dec. 17, 1996 issued to Teetzel, includes the use of IR lighting and IR laser sights. When a shooter does not wish to endanger themself as a target, they switch to IR illumination and IR laser sighting. While no visible signature illuminates the shooter to an opponent, the shooter must now wear night vision seeing technology, preferably in goggle form, to view the intruder. Typical night vision equipment consists of a low light-level CCD camera with an image display. Night vision equipment has in the past been bulky and is certainly not designed for rapid response. Upon engagement with an intruder, a person seeking to protect themselves would have to power up the night vision equipment, put the night vision goggles on, locate their weapon, and power on the IR laser, to be in a readiness state. Not only is the time required for this sequence potentially hazardous, the additional motions required can also disclose your location and intent. What is ideally needed is a rapidly actuated firearm for protection that is equipped with a compact calibrated laser sight that can be used in a stealth mode that utilizes non-visible laser illumination and has built in night vision capability for sighting. It will be appreciated that such a firearm of this nature, while portrayed as a weapon of self-defense has many applications for law enforcement and military use as well. As an offensive weapon, this sighting technology facilitates stealth approach and targeting. It can be used with a host of military firearms, such as the M4 carbine and the M16 rifle. 
       SUMMARY OF THE INVENTION 
       [0005]    It is therefore an aspect of the present invention to provide stealth non-visible laser sighting for a firearm. 
         [0006]    It is further an aspect of the present invention to provide both visible laser sighting and stealth non-visible laser sighting for a firearm. 
         [0007]    It is further an aspect of the present invention to provide an attached means to image and display the non-visible laser. 
         [0008]    It is further an aspect of the present invention to provide stealth laser sighting capability integral to a firearm. 
         [0009]    It is further an aspect of the present invention to provide a compact stealth laser sighting apparatus as an accessory that can be retrofitted to firearms not factory equipped. 
         [0010]    It is further an aspect of the present invention to provide mounting interchangeably above or below the barrel of the weapon. 
         [0011]    It is further an aspect of the present invention to provide rapid or automatic actuation of all laser sighting and imaging means. 
         [0012]    It is further an aspect of the present invention to provide mechanical or electronic adjustment for calibrating the laser to the gun barrel. 
         [0013]    It is further an aspect of the present invention to provide mechanical or electronic adjustment for calibrating range (elevation) and windage. 
         [0014]    It is further an aspect of the present invention to provide automatic detection of range and electronic adjustment of sighting. 
         [0015]    It is further an aspect of the present invention to provide image zoom capabilities to accurately sight long-range targets. 
         [0016]    It is further an aspect of the present invention to provide a laser crosshair that projects range and windage adjustments on a target. 
         [0017]    It is further an aspect of the present invention to provide memory means to record targeting and shooting events. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitations of the present invention, and wherein: 
           [0019]      FIG. 1  is a side view of a stealth laser sighting system attached to a typical handgun according to one embodiment of the present invention. 
           [0020]      FIGS. 2A and 2B  are perspective views of the stealth laser system in accessory form according to the present invention. 
           [0021]      FIGS. 3A ,  3 B, and  3 C are perspective views of the stealth laser system in accessory form according to an alternate embodiment of the present invention. 
           [0022]      FIGS. 4A and 4B  are front views of the stealth laser system in accessory form according to the present invention. 
           [0023]      FIGS. 5A and 5B  are side views of the stealth laser sighting system in accessory form illustrating alternate attachments to a typical handgun according to the present invention. 
           [0024]      FIG. 6  is a side view of a stealth laser sighting system attached to an M- 16  rifle according to the present invention. 
           [0025]      FIG. 7  is a perspective view of a stealth laser sighting system according to another embodiment of the present invention. 
           [0026]      FIG. 8  is a perspective view of the stealth laser sighting system using dual laser diodes according to the present invention. 
           [0027]      FIGS. 9A and 9B  are electrical schematic diagrams of laser diodes. 
           [0028]      FIG. 10  is a perspective view of a stealth laser sighting system using a photo detector for sensing range according to the invention. 
           [0029]      FIG. 11  is top view of a circuit board according to the present invention. 
           [0030]      FIGS. 12A-12E  are perspective views showing an image display according to the present invention. 
           [0031]      FIGS. 13A and 13B  are perspective views showing the image display with zoom feature according to the present invention. 
           [0032]      FIG. 14  is a side view of a stealth laser sighting system integrated within a typical handgun according to yet another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0033]    Referring to  FIG. 1  there is shown a typical handgun  10  that as illustrated is by way of example a Beretta pistol. The handgun  10  has a barrel  15  that is the tube that a bullet travels down when fired. Along the top of the barrel  15  is a mounting base  16 , which fastens accessories such as gun sights and scopes to the firearm. There are several types of mounting bases: a Weaver base, a Ruger base, a Leopold base, various .22 bases or “dovetail” bases are the most common. Attached to the mounting base  16  is mounting adapter  17  which fastens a stealth laser sighting system  19  in accessory form in accordance with the present invention to the handgun  10  and contains mechanical adjustment for elevation and windage. 
         [0034]      FIG. 2A  illustrates the stealth laser sighting system  19 , shown by way of example in accessory form in accordance with the present invention. The stealth laser sighting system  19  houses all the components necessary to project a non-visible or visible laser dot, and to then image and display the non-visible dot on its intended target. Referring to  FIGS. 2A and 2B  the stealth laser sighting system  19  includes laser module housings  21  and  23  which contain laser modules  22  and  24  respectively. The laser modules are factory calibrated to be aligned with parallel axial alignment to each other with beams projected normal to the front surface of the stealth laser sighting system  19 . Each laser module contains a laser diode of a specific wavelength, appropriate optics to collimate and focus laser light, and driver circuitry for driving the laser diode. It should be noted that the electromagnetic spectrum is only visible in the range of 380 to 780 nm. The wavelengths of the electromagnetic spectrum immediately outside the range that the human eye is able to perceive are called ultraviolet (UV) at shorter wavelengths (high frequency) and infrared (IR) at longer wavelengths (low frequency). Laser module  22  contains a laser diode that projects visible light and is tuned to a predetermined wavelength, such as a wavelength of 635 nm. It will be appreciated that the visible light emitting laser diode can be tuned to any wavelength that is in the visible spectrum. Laser module  24  contains a laser diode that projects IR non-visible light and is tuned to a predetermined wavelength, such as a wavelength of 830 nm. It will be appreciated that the non-visible light emitting laser diode can be tuned at any wavelength that is outside of the visible spectrum that can be imaged and displayed to make the non-visible light beam visible. An imaging element  25  is used to capture and transmit real-time video. Imaging element  25  is designed to image light in the non-visible spectrum and shift the light into video in the visible spectrum. The imaging element  25  is designed to be in parallel axial alignment with the laser modules  22  and  24  and image the field of view where laser modules  22  and  24  illuminate a target. Ideally the center of imaging element  25 &#39;s field of view would be located along the axis of the laser modules  22  and  25 . In one embodiment of the imaging element  25 , the imaging element is a low light level (lux) CCD imager capable of producing a grayscale composite video image. The imaging element  25  has by way of example a 92-degree field of view with a pinhole lens, and has 420 lines of video resolution. Most importantly the spectral sensitivity of the CCD imager is by way of example from 200 nm-1000 nm that allows both visible and non-visible light to be displayed within the visible grayscale output as a video stream. Another important feature of the CDD imager is that it only requires, by way of example, as little as 0.01 Lux illumination, which produces very high contrast images in extremely low light situations. While this embodiment of the imaging element  25  uses a pinhole lens, it will be appreciated that any imager can be outfitted with any combination of lens assemblies to provide a fixed or variable zoom to provide any field of view desired. The imaging element  25  provides a continuous video stream to the image display  27 . The image display  27  is provided by any display technology that provides high-resolution video in a compact display that requires minimal power. In one embodiment of image display  27 , the display is a TFT graphic video LCD assembly that contains by way of example 640×480 pixels, displays 4096 colors, is a 1.8 inch (45 mm) diagonal display with a 1.8 inch (45 mm)×1.8 inch (45 mm)×0.25 (6 mm) inch footprint. The image display  27  is located on the top surface of the stealth laser sighting system  19  and is angled downward from front to back to allow clear visual inspection while in a comfortable shooting position with the gun held at arms length in front of one&#39;s body at chest height. A battery compartment  26  holds by way of example either lithium or alkaline batteries, or batteries that can be recharged and are selected to allow for a predetermined number of hours of usage, such as several hours of continuous use. Universal mounting feature  28  is a keyed mating recess designed to accept all of the previously described mounting adaptors  17 . The recessed design requires proper orientation and facilitates a rigid mount that is required to maintain the calibration between the sight and the gun. A three-way switch  29  has by way of example a center off position, a leftmost position powers up all components providing operation in a stealth mode, and a rightmost position powers up all components providing operation in a visible mode. 
         [0035]      FIGS. 3A ,  3 B, and  3 C and  FIGS. 4A and 4B  illustrate another embodiment of stealth laser sighting system  19 . In this embodiment the imaging display  17  pivots using hinge  32 . Within hinge  32  is a rotary switch  33  that automatically powers up the stealth laser sighting system  19  in a stealth mode when the imaging display  17  is opened. Stealth mode powers up a non-visible light emitting laser  24 , imaging element  25  and imaging display  17 . This automatic power actuation allows for rapid deployment of a firearm in an emergency situation. To switch to a visible mode, one needs simply to depress a mode switch  34 . A single actuation of mode switch  34  will turn off the non-visible light emitting laser  24  and turn on a visible light-emitting laser  22 . Actuation again of mode switch  34  will turn off the imaging element  25  and imaging display  17 , which conserves power since the visible source can be seen without the aid of imaging element  25  and the imaging display  17 . Depressing mode switch  34  again will begin the cycle again and place the stealth laser sighting system  19  into the stealth mode. 
         [0036]      FIGS. 3C and 4B  show how compact the profile of the stealth laser sighting system  19  is when the display housing  35  is in the closed position. The intent of the narrow profile when the imaging display  17  is closed is to contain the module as much as possible within the confines of the handgun to enable holstering the firearm. 
         [0037]      FIGS. 5A and 5B  illustrate multiple mounting locations of the stealth laser sighting system  19  to handgun  10 . 
         [0038]      FIG. 6  illustrates the preferred use of the stealth laser sight  19  when attached to an automatic or semi-automatic firearm  60 , which as illustrated is by way of example an M- 16  army rifle. 
         [0039]      FIG. 7  illustrates the use of a single laser element on stealth laser sighting system  19 . This version does not contain the visible laser module  22  or a laser module housing  21 . 
         [0040]    Referring to  FIGS. 8 ,  9 A, and  9 B,  FIG. 8  illustrates a stealth laser sighting system  19  that uses a dual output laser module  80 . The dual output laser module  80  contains a single set of collimating optics, a dual laser diode and driver circuitry.  FIG. 9A  illustrates a typical schematic for a single mode visible light emitting laser diode  90 . Single mode visible light emitting laser diode  90  typically includes a photodiode  92  that is used to provide feedback to control the output of the laser power and includes a laser diode  94  that is tuned to produce laser light in the visible spectrum.  FIG. 9B  illustrates a typical schematic for a dual mode laser diode  95 . The dual mode laser diode  95  includes a photodiode  92 , a laser diode  94  tuned to the visible spectrum, and a laser diode  96  tuned to the non-visible spectrum. This packaging conserves cost and space that is critical for compactness, and eliminates the machining tolerance to make the separate visible and non-visible laser modules parallel as described above regarding  FIGS. 2A and 2B . 
         [0041]      FIG. 10  illustrates the addition of a photo detector  50  that senses laser light for purposes of calculating the range to a target. A laser range finder, or LIDAR (Light Detection And Ranging), uses the laser beam from laser module  22  in order to determine the distance to an opaque object. The laser range finder works by sending a laser pulse in a narrow beam towards a target and measuring how long it takes for the pulse to bounce off the target and return. The pulse can be coded in order to reduce the chance that the laser range finder can be jammed. It will be appreciated that a LIDAR that uses very short (sharp) laser pulses and has a very fast detector can range on object to within a few centimeters. The distance from the firearm to the target is used to set the laser sight elevation, to calibrate where the bullet will strike a target. 
         [0042]      FIG. 11  is a view of a circuit board  51  that is enclosed within stealth laser sighting system  19 . Circuit board  51  incorporates a micro controller unit  52  that can perform calculations and processes for the LIDAR. Circuit board  51  also can incorporate an accelerometer IC  53  and associated circuitry that can detect motion of the firearm and automatically power up the stealth laser sighting system  19  in stealth mode for quick firearm response. Circuit board  51  also can incorporate a display driver  54  that is used to process all of the video information, add video overlays, and drive the imaging display  27  as required. A memory  62  can be incorporated to record the video information delivered from the imaging element  25 . The memory  62  can be permanently incorporated onto the circuit board  51 , or can be removable, such as provided using a Flash RAM or a flash memory card. The content of memory  62  can be reviewed or transferred to other media, and used as visual evidence of the circumstances of the discharge of the firearm. 
         [0043]      FIG. 12A  illustrates an image as seen on imaging display  27  when the stealth laser sighting system  19  is used in stealth mode. A laser spot  55 , which is not visible directly on the target to the human eye, shows up on the imaging display  27  on the intended target where a bullet will strike once the stealth laser sighting system  19  and firearm are mechanically aligned and calibrated to each other as described above. 
         [0044]      FIG. 12B  illustrates the addition of laser apertures  56  that cause the stealth laser sighting system  10  to project a targeting grid  57  on the target instead of projecting just a laser spot  55  as described above. Laser apertures  56  can have, as shown by example, cross hatches that are indicative of windage and elevation adjustments that can be made prior to shooting by aiming the sight through a particular cross hatch on targeting grid  57  instead of the center of the target crosshair on targeting grid  57 . 
         [0045]      FIG. 12C  illustrates the addition of an electronic video overlay of a crosshair  58 . The electronic video overlay of a crosshair  58  highlights the location of laser spot  55 , which makes the laser spot  55  easier to see on imaging display  27 . Additionally the electronic video overlay of the crosshair  58  can have cross hatches that are indicative of windage and elevation adjustments, as described above, that can be made prior to shooting by aiming the sight through a particular cross hatch instead of the center of the target crosshair. In this case the laser spot  55 , imaging element  25 , and the handgun  10  need to be mechanically aligned, for the calibrations to aim the firearm effectively. 
         [0046]      FIG. 12D  illustrates when the laser spot  55  and the handgun  10  are not mechanically aligned. To accurately calibrate the stealth laser sighting system  19  and the handgun  10 , an electronic video overlay of a crosshair  59  is manually positioned using a button-sized joystick  68  where the bullet would strike when aimed. A similar sighting process known in the art for mechanical alignment of a sight and a gun would be used to perform this calibration accurately. To accurately fire the firearm, the shooter would align the target with crosshairs  59  instead of the actual laser spot  55 . 
         [0047]      FIG. 12E  illustrates an auto laser range finder that would automatically offset crosshair  65  to account for range relative to the laser spot  55 . The shooter would aim at the center of the crosshair to place a bullet accurately in the target from the actual distance the firearm was fired. 
         [0048]      FIG. 13A  illustrates a long range shot as imaged on imaging display  27 . Upon actuation of a digital zoom button  69  or rotational adjustment of a zoom lens  77 , the image illustrated in  FIG. 13B  zooms in to fill the viewing screen to make it easier to sight the target. It will be appreciated that both optical zoom, where a lens attached to the imaging device  17  is rotated, and digital zoom, where a portion of the image is digitally enlarged, serve identical functions. 
         [0049]      FIG. 14  takes all of the features described above as a modular accessory for a small firearm and integrates the stealth laser sighting system  19  directly into the housing of firearm  100 . All of the stealth features and functionality of the stealth laser sighting system  19  are contained within the firearm body and all rigid alignments are maintained. 
         [0050]    It will thus be seen that the description set forth above, and those made apparent from the preceding descriptions, are effectively attained and since certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense. 
         [0051]    It is also to be understood that the following claims are intended to cover all generic and specific features of the invention herein described and all statements of scope of the present invention, which as a matter of language, might be said to fall there between.