GB2448314A

GB2448314A - Night vision attachment for a telescopic sight

Info

Publication number: GB2448314A
Application number: GB0706823A
Authority: GB
Inventors: Diane Worthington
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-10
Filing date: 2007-04-10
Publication date: 2008-10-15
Also published as: GB0706823D0

Abstract

A night vision attachment can be connected to a telescopic sight to convert it into a night vision sight. The attachment may comprise the parts outlined in the following sentences. On exiting from the eyepiece of the telescopic sight 1 light is reflected by mirrors 2 and 3 towards lens 4. The lens focuses light on the photocathode 5 of the image intensifier 6. An enhanced image is then formed on the phosphor screen 7 of the image intensifier, which is then captured by the camera 8 to transform the visual image into electronic format. This is then processed by signal processing within the control unit 10 and sent to the electronic viewfinder. The control unit 10 is also used for control functions. The electronic viewfinder is comprised of a minidisplay 12 and an eyepiece 14.The minidisplay is a display so small that magnifying optics are needed to make the image visible to the human eye. The eyepiece 14 magnifies the image formed on the minidisplay screen 13 to make the image suitable for observation. The image is then reflected by mirrors 15 and 17 towards the operator's eye. The battery 11 provides the necessary power to run the electronic components. The connecting interface 9 is used to connect the electronic parts and modules of the device.

Description

Night vision attachment.

This invention relates to a night vision device that can be attached to a telescopic sight or other optical devices.

Telescopic sights are optical instruments used for the accurate aiming of weapons, in particular for applications such as hunting or combat. Using optical elements a telescopic sight magnifies a directly visible target and therefore improves accuracy of shooting.

Telescopic sights are most effective in daylight and have limited capability in low light conditions and at night For night-time aiming a night vision sight is needed. Night vision devices use both optical and electronic components. In these instruments, image intensifiers, or other devices amplify incident light from the scene so that objects are made visible to the viewer. In these devices the image is focused onto the photocathode of an image intensifier. The photocathode responds by releasing free electrons, which are then multiplied and accelerated towards a phosphor screen. When the electrons strike the screen they create a visible image.

Image intensifiers or Image intensifying tubes are currently the most popular image-enhancing components for mobile and compact night vision devices, including night sights. Also, solid-state semiconductor sensors, for example CCD's (charge-coupled device), can be used as image intensifying devices.

Night vision sights, however, have some limitations if used in daylight. These include low resolution, low magnification and the necessity to protect expensive components from light overload. For this reason, if both a daytime and night-time capability is needed, two weapons may be required. One mounted with a daytime telescopic sight and the other mounted with a night vision sight Or one weapon and two sights which can be interchanged. Both methods can be inconvenient; carrying two rifles substantially limits the mobility of a person, and changing sights on a rifle requires the bore sighting or zeroing of the weapon each time the sight is changed.

To overcome this problem attempts have been made to combine day and night sights.

Described in Patent US5946 132 is a device using elements of a daytime telescopic sight and image intensifying parts in one housing. These systems have the serious disadvantage of being both bulky and expensive to manufacture. Also, hybrid devices tend to sacrifice both day and night perfonnance.

As an alternative to hybrid sights there are a variety of night vision attachments available, that allow the day time telescopic sight to be converted into a night vision device. This is achieved by means of attaching a night vision device to the front or back of the telescopic sight. For example, described in Patent US4629295 is an Image intensifying device that can be attached in front of or to the objective lens of a daytime optical instrument. This has the disadvantage of being bulky, heavy and expensive to manufacture. Also, any misalignment of the front night vision attachment with the light path of the telescopic sight will cause a zero shift. Also, the balance of the weapon may be seriously impaired by the added weight to the front part of the telescopic sight.

The most popular night vision attachments are those that attach to the back of telescopic sights. Usually they are night vision monoculars that attach to the eyepiece part of the telescopic sight by means of a mount. Because night vision monoculars are affordable and widely available, the back attachment option is much more cost effective and a technically simpler solution than any hardware mentioned above.

Because it is attached to the back of the telescopic sight, the alignment is not critical and won't cause zero shift. Another advantage is that the night vision unit also can be used as a hand-held night vision observation device. Patent US64494 19 describes a mounting device which allows the mounting of a night vision monocular to the telescopic sight.

However currently available night vision back attachments have the serious disadvantage of adding substantial length to the back of telescopic sight. This is because the night vision monocular needs to be attached to the back of the sight, in a straight line with it, and are usually at least 5" in length. Figure 1 shows the operator's eye in relation to the telescopic sight 28 in the normal shooting position.

This position is marked by the line 27. Figure 3 shows the telescopic sight 28 with a conventional night vision monocular 30 attached to it. It necessitates the operator to move their eye some distance back from the position marked by line 27, therefore disturbing the normal balance of the weapon and making holding and aiming difficult.

Also night vision monoculars used in night vision attachments usually have short eye relief and do not provide enough safety margin against weapon recoil, that requires eye relief to be 50-90 mm.

To overcome this, the proposed invention proposes a night vision attaclunent, which adds substantially less length to the back of the telescopic sight it is attached to. This is achieved by combining the use of a folded light path with an electronic viewfinder, which allows the packaging of most elements of the attachment around the eyepiece of the telescopic sight rather then behind it. Figure 2 show the proposed night vision attachment 29 attached to the telescopic sight 28. The operator's eye position is only slightly altered from the optimal position shown in Figure 1 (in some implementations the eye position remains unaltered), therefore allowing comfortable aiming and also providing plenty of eye relief for rifles with recoil. The proposed night vision attachment can also be used as a hand held night vision monocular.

Examples of how this invention can be implemented will now be described with accompanying drawings: -figure 4 shows the light path arrangement with one of the possible juxtapositions of the main components of the proposed invention.

-figures 5,6,7 & 8 show possible variations in implementation of the proposed invention.

-figures 9 &10 show one of the possible visual appearances of the proposed invention as a complete product.

Figure 4 shows the light path arrangement with one of the possible juxtapositions of the main components of the proposed invention. In figure 4, for convenience of explanation, the housing of the proposed night vision attachment is not shown. On the exit from the eyepiece of the telescopic sight I light is reflected by mirrors 2 and 3 towards Lens 4. This Lens focuses light onto the photocathode 5 of the image intensifier 6. The enhanced image formed on the phosphor screen 7 of the image intensifier is then captured by camera 8 to transform the visual image into an electronic format. This is then processed by signal processing within unit 10, which is also used for control functions, and sent to an electronic viewfinder. The electronic viewfinder is comprised of a minidisplay 12 and an eyepiece 14. The minidisplay is a display so small that magni1ing optics are needed to make the image visible to the human eye. An eyepiece 14 magnifies the image formed on the minidisplay screen 13 to make the image suitable for observation. The image is then reflected by mirrors 15 and 17 towards the operator's eye. The battery 11 provides the necessary power to run the electronic components. The connecting interface 9 is used to connect the electronic parts and the modules of the device. Figure 9 shows an example of one of the possible visual appearances of the proposed invention as a complete product. All components are enclosed in the housing, which can be attached to the telescopic sight and securely locked using screw 32. The unit is controlled by push buttons 31. Cover 33 allows access to battery compartment There can be variations in the implementation of this invention.

Figure 5 shows a variation where an off-the-shelf commercially available, or military, night vision monocular 20 can be used as an image intensifying part of the proposed attachment. The night vision monocular 20 contains an objective lens 21, the main body with image intensifier and an eyepiece 22. Camera 8 captures the intensified image through the night vision monocular eyepiece 22. It is then processed by signal processing within the control unit 10, which is also used for control functions, and seat to an electronic viewfinder. The electronic viewfinder is comprised of a minidisplay 12 and an eyepiece 14. The minidisplay is a display so small that magnifying optics are needed to make the image visible to the human eye. The eyepiece 14 magnifies the image formed on the minidisplay screen 13 to make the image suitable for observation. The image is then reflected by mirrors 15 and 17 towards the operator's eye. The battery 11 provides the necessary power to run the electronic components. The connecting interfce 9 is used to connect the electronic parts and modules of the device. The monocular is coupled to the night vision attachment in a way that allows it to be detached if required and used as a hand held monocular. Figure 10 shows an example of one of the possible visual appearances of the proposed invention as a complete product. The off-the-shelf commercially available, or militajy, night vision monocular 20 is installed into the proposed night vision attachment as in a cradle. The camera S captures the intensified image through the monocular's eyepiece 22 to convert it into an electronic format. All components are enclosed in the housing, which can be attached to the telescopic sight and securely locked using screw 32. The unit is controlled by push buttons 31. The image is observed through the eyepiece 32.

Figure 6 shows a variation of the proposed night vision attachment where a solid-state semiconductor sensor (for example CCD -charge-coupled device) can be used as an image intensifying device. The CCD based camera 19 is used as the image capturing and intensifying component. It is then processed by signal processing within the control unit 10, which is also used for control functions, and sent to an electronic viewfinder. The electronic viewfinder is comprised of a minidisplay 12 and an eyepiece 14. The minidisplay is a display so small that magnifying optics are needed to make the image visible to the human eye. The eyepiece 14 magnifies the image formed on the minidisplay screen 13 to make the image suitable for observation. The image is then reflected by mirrors 15 and 17 towards the operator's eye. The battemy 11 provides the necessary power to run the electronic components. The connecting interface 9 is used to connect the electronic parts and modules of the device.

Figure 7 and 8 show two possible variations in the arrangement of components of the electronic viewfinder.

Figure 7 shows a variation of the invention where the eyepiece 14 is placed after reflecting mirrors 17 and 15. In this variation lens 22 maybe required to convey the image from the ininidisplay 12. FigureS shows a variation of the invention where only one reflective mirror is used to form the viewfinder light path.

It should be understood that many other variations and modifications regarding the implementation of this invention, utilizing components functionally equivalent to those described above, can be made. Any and all such variations or modifications, as well as others which may become apparent to those skilled in the art, are intended to be included within the scope of the invention as defined by the appended claims.

Claims

Claims 1. A Night Vision attachment that can be connected to a

telescopic sight to convert it into a night vision sight.
2. A Night Vision attachment according to claim 1 where the light path from the telescopic sight eyepiece is reflected by an optical element towards the attachment's image intensifying part.
3. A Night Vision attachment according to claim 2 where the reflective optical element can be a mirror or prism or any other element(s) with a reflective surface.
4. A Night Vision attachment according to claim 2 where the reflected light path can be created by one or more optical elements.
5. A Night Vision attachment according to claim 1 where the light intensifying element can be an image intensifying tube, or a solid-state semiconductor sensor (for example CCD -charge-coupled device) or other suitable components.
6. A Night Vision attachment according to claim 1 where a camera is used to capture the visual image formed on the phosphor screen of the image intensifier and convert it into an electronic format that is then used for forming an image on the minidisplay of the electronic viewfinder.
7. A Night Vision attachment according to claim I where the intensified image is observed by an operator through an electronic viewfinder.
8. A Night Vision attachment according to claim 7 where the electronic viewfinder is comprised of a minidisplay and optical elements necessary to magnify the image formed on the minidisplay.
9. A Night Vision attachment according to claim 8 where reflective optical elements can be used to direct the image that is formed on the minidisplay towards the eye of an operator.
10. A Night Vision attachment according to claim 9 where reflective optical elements can be a mirror or a prism or any other element(s) with reflective surface.
II. A Night Vision attachment according to claim 9 where the reflected light path can be created by one or more optical elements.
12. A Night Vision attachment according to claim I where an off-the-shelf commercially available, or military, night vision monocular can be used as a part of the proposed night vision attachment.
13. A Night Vision attachment according to claim 12 where the off-theshe1f commercially available, or military, night vision monocular can be easily installed onto, or removed from, the proposed night vision attachment.
14. A Night Vision attachment according to claim I, which incorporates a mounting mechanism, that allows for securely mounting the proposed device to the telescopic sight.
15. A Night Vision attachment according to claim 1, which is contained in a protective housing with controls batons or switches located on it.
16. A Night Vision attachment according to claim 1, which is powered by an internal or external battery or batteries.
17. A Night Vision attachment according to claim 8 where the minidisplay can be an LCD, LCOS, DMD, DLP or OLED display.
IX. A Night Vision attachment according to claim 1, which can incorporate an infrared illuminator.
19. A night vision attachment according to claim I where the operating functions, which are controlled using control buttons or switches located on the housing, include: the control for switching the device on and off; the control for brightness, contrast, colour, zoom, presets and program functions, power of infrared illumination.
20. A Night Vision attachment according to claim I which can also be used as an attachment to other optical instruments such as telescopes, binoculars, monoculars, etc, in order to convert them into night vision devices.