JP7393951B2 - Sighting scope with illuminated sight and thermal imaging camera - Google Patents

Description

The field of the invention is that of sighting scopes, including thermal imaging cameras and illuminated sights.

Infantry requires the following to carry out its various missions using its weapons:
- day and night firing capabilities, which require precise aiming to best use one's weapon, ideally for effective fire beyond 300 meters;
- rapid aiming in dynamic combat situations;
- Maintaining superior situational awareness to respond to any threats that may arise on the battlefield during the day and night. This situational awareness specifically involves maintaining a wide field of vision encompassing the surrounding space;
- the ability to "decamouflage" or perceive threats both during the day and at night;
- separation reflected especially at night through the absence of light emission from the aiming element;
- no muzzle aiming setting action to switch from daytime aiming to night aiming (and vice versa) in order to save time and ensure reliability of aiming;
- Mobility and durability requiring equipment that is as light and compact as possible.

These needs are reflected by strong requirements for sighting elements equipped on assault rifles provided to infantry. In fact, these requirements are only partially met, and not at all by a single piece of compact and lightweight equipment.

The usual solutions for ensuring alignment in assault rifles are as follows. For daytime aiming, the weapon essentially includes an eyepiece-sight assembly. This assembly is simple, robust, and inexpensive, but provides little accuracy.

The weapon may also include the following for daylight aiming:
- Illuminated sight. That is, an optical assembly that allows luminous symbols or dots to be superimposed outside the aiming axis. This illumination sight can optionally be associated with switchable magnification optics. As an example, the magnification is 3.
- Laser pointer.
- Daytime magnification scope.
For night aiming, the weapon can include:
- Laser pointer.
- A sighting scope with a light-enhanced sighting scope called an "IL" scope.
- Infrared aiming scopes called "IR" scopes.
- A light intensifier or infrared adapter or "clip-on" placed upstream of the daytime sighting scope.
- Aiming devices, including night glasses associated with illuminated sights fixed to the weapon.

Each of these known solutions has advantages and disadvantages, but none fully addresses the overall need identified above.

The illuminated sight solution is particularly well thought out. Because, while providing excellent accuracy, it allows aiming and firing with both eyes open, and allows eye positioning relatively far from the illumination sight optics, allowing the eye to be positioned close to the eyepiece. This is because they maintain good awareness of the overall situation unless they need to be close. The shooter can keep both eyes open and the illuminated sights will tell the landscape without magnification.

Aiming with a laser pointer, which is widely used especially at night, is very advantageous. This is because it allows rapid fire in dynamic combat without the need for the eyes to be aligned behind the sight or even to carry the weapon in extreme situations. On the other hand, laser pointers remain unreliable, especially at night. Even if it is a pointer that emits near-infrared radiation, it is easily detectable even with night vision glasses or certain equipment using near-infrared sensitive cameras.

Whether the sighting scope is a daytime scope or a nighttime scope, sighting scopes with thermal beam enhancement or thermal infrared generally offer accuracy advantages, especially due to their magnification. They exhibit the drawback of requiring the eye used for aiming to be placed close to the eyepiece. Furthermore, the user cannot use the other eye for the overall picture. This operation takes a certain amount of time, which constitutes a loss of efficiency in dynamic combat. Additionally, the shooter may be momentarily disconnected from his or her environment and may not be aware of new threats at that time. Finally, at night, when wearing night vision glasses, the combatant must remove his night vision glasses so that he can accurately place his free eye behind the sighting scope. It also represents additional delay in combat and separation of the combatant from the environment.

Infrared or thermal imaging sighting scopes exhibit the same disadvantages, but have a few significant advantages, namely night vision, including in complete darkness, improved visibility in battlefield fog and smoke, and, above all, the ability to detect any hot target. ``camouflage'' ability.

It is possible to juxtapose several systems within a single piece of equipment to try to provide an appropriate response. For example, as can be seen in FIG. 1, some sighting equipment items combine an IL or IR sighting scope with an illuminated sight at the apex. In this case, the scope includes a thermal imaging camera and a viewing device. The thermal imaging camera includes a focusing lens 1 and a photosensitive receiver 2. The viewing device includes a microdisplay 3 and an eyepiece 4. The illuminated sight includes a luminous symbol 5 and optics 6 for collimation and superimposition with a direct sight 7.

These solutions result in relatively bulky equipment that provides juxtaposition of functionality without the functionality being combined. At a given moment, the user must choose to use either the illuminated sight or the scope, and thus does not benefit from the cumulative advantages of both systems. For systems that associate thermal infrared scopes and illuminated sights, users benefit from the rapid aiming and situational awareness provided by the illuminated sights, or from the decamouflage and night vision provided by thermal imaging scopes. must choose between profiting from.

In summary, existing solutions based on a single principle of optical sights, pointers or scope types do not meet all the needs of infantry to fire in any situation. Solutions that juxtapose two principles in the same equipment, e.g. illuminated sights and thermal imaging scopes, can aggregate specific advantages rather than allowing one to benefit from all of them at the same time. do it like this. Furthermore, these systems are bulky and heavy. They do not meet all of the needs identified above.

The scope according to the invention does not have the above-mentioned drawbacks. In fact, several images from different sources are perceived by a single eyepiece of the illumination sight type. Therefore, some of the requirements of this type of equipment are guaranteed while retaining a reduced bulk. More specifically, the subject matter of the present invention is an aiming or spotting scope that includes a camera and a video microdisplay associated with an eyepiece in a single mechanical structure, wherein the eyepiece is configured to superimpose a video microdisplay image onto an external landscape. A sighting or spotting scope characterized in that it uses a light combiner located in the.

Advantageously, the scope includes luminous symbols or dots and an optical device arranged to superimpose the image of the luminous symbols or dots on the image of the video microdisplay and on the external landscape.

Advantageously, the optical chain consisting of camera, microdisplay and eyepiece has a magnification of 1, and the microdisplay image is matched to the image of the external landscape.

Advantageously, the light combiner includes a planar semi-reflective surface tilted at approximately 45 degrees to the aiming or positioning axis.

Advantageously, the semi-reflective surface is incorporated into a splitter plate comprising two planar and parallel surfaces.

Advantageously, the semi-reflective surface is incorporated into a splitter cube comprising two planar and parallel surfaces. The normal to the plane may be parallel to the aiming or positioning axis.

Advantageously, the splitter prism includes a reflective concave mirror, the optical axis of the reflective concave mirror is perpendicular to the aiming or positioning axis, and the light rays from the video microdisplay are transmitted by the semi-reflective plate and reflected by the concave mirror. , then reflected by a semi-reflective plate.

Advantageously, the splitter prism includes a convex input surface, the optical axis of the convex input surface being perpendicular to the aiming or positioning axis and opposite the concave mirror.

Advantageously, the light combiner includes a "free-form" or diffractive type concave semi-reflective surface tilted with respect to the aiming or positioning axis, and the eyepiece includes a convex mirror associated with the concave semi-reflective surface.

Advantageously, the optical device comprises a splitter plate or a splitter cube arranged in front of the video microdisplay, so that the image of the luminescent symbols or dots is interlaced with the video microdisplay by reflection or transmission by the splitter plate or splitter cube. be combined.

Advantageously, the camera is a thermal infrared or low light level camera.

The invention will be better understood and other advantages will become apparent from reading the following description, which is given in a non-limiting manner and from the accompanying drawings, in which: FIG.

Represents the prior art sighting scope-illuminated sight combination as previously described. 1 represents a perspective view of a sighting or spotting scope according to the invention; FIG. 1 represents a manufacturing method for a sighting or spotting scope according to the invention; 1 represents a first embodiment of an eyepiece according to the invention; FIG. Figure 2 represents a second embodiment of the eyepiece according to the invention. 3 represents a third embodiment of an eyepiece according to the invention. Figure 3 represents an alternative embodiment of the aiming or spotting scope according to the invention, including the generation of a collimated luminescent dot. 4 represents a fourth embodiment of an eyepiece according to the invention.

FIG. 2 represents a perspective view of a sighting and spotting scope according to the invention. It essentially includes two main subassemblies: a camera 10 and a viewing device 15 including an eyepiece with a microdisplay and a light combiner. The optical combiner is mounted on top of the camera. The assembly of optical and electronic components is incorporated into a sealed structure 80 that protects the components from the external environment and impacts.

The structure includes a mechanical fixation interface 85 that allows the structure to be fixed on a weapon equipped with a standard interface. This interface is, for example, a "Picatinny" rail or its equivalent.

Its structure provides, among other things, on/off control of different functions of the equipment, video microdisplay brightness settings, electronic and mechanical muzzle aiming settings, electronic settings for superimposition of different images generated with respect to the external landscape. It also includes a set 87 of enabling buttons and control members. It can be placed on one of the two side relief surfaces of the scope. As an example, in FIG. 2, the set includes three buttons located on the left side flank of the scope, and the other buttons are located on the left flank of the scope.

FIG. 3 represents a first embodiment of a sighting or spotting scope according to the invention. The following conventions were adopted for this figure and subsequent figures. Optical or mechanical elements are represented by thick lines, light rays are represented by thin lines, and optical axes are represented by dotted lines. For clarity, only rays on the optical axis are represented.

The camera is preferentially a thermal imaging camera consisting of an infrared lens 20 operating in the spectral band located between 8 μm and 12 μm and an infrared sensor 25 with a microbolometer sensitive in the same spectral band.

The camera can be a low-noise "CMOS" sensor ("CMOS" is an acronym for "complementary metal oxide semiconductor") or an "EB-CMOS" sensor ("EB-CMOS" is an acronym for "electro-impact CMOS"). It can also be a low-light level camera that implements the following acronym: The camera can also be a "SWIR" camera ("SWIR" is an acronym for "Short Wave Infrared") that operates in the 1 μm to 2 μm spectral band, senses light from nightglow, and also provides decamouflage capabilities. could be.

This camera, as well as the power supply, sensor drive and image processing electronics 30, consists of several battery cells or blocks of rechargeable batteries that can be placed behind the scope on the viewing eye side to ensure the autonomy of the camera. It includes a power supply unit 40 that accommodates the.

The viewing device includes a microdisplay 50, an eyepiece 60 with a light combiner 70, and the necessary electronics to power and drive the microdisplay.

This microdisplay 50 displays a video aiming reticle optionally enhanced with sight correction elements or optical distance measuring symbols or graduations. It also displays thermal infrared images of the scene from a thermal imaging camera.

This microdisplay may be, for example, an "OLED" display ("OLED" is an acronym for "organic light emitting diode"), "LCD" ("LCD" is an acronym for "liquid crystal display"), " LCOS" display ("LCOS" is an acronym for "Liquid Crystal on Silicon").

The optical chain consisting of camera, microdisplay and eyepiece has a magnification of 1, and the microdisplay image is matched to the image of the external landscape. The light combiner ensures perfect placement of the microdisplay image onto the external landscape.

Eyepieces with optical combiners have different possible embodiments.

In a first embodiment illustrated in FIGS. 4, 5 and 8 representing different optical eyepiece combinations, the optical combiner includes a planar semi-reflective surface tilted at 45 degrees to the aiming or positioning axis. This surface has no optical power.

This surface may belong to a semi-reflective plate with thin, flat and parallel surfaces as seen in FIG.

As shown in FIGS. 4 and 5, this plate can advantageously be incorporated into a splitter cube containing two planar and parallel faces in order not to introduce distortions on the external landscape. The normals to these planes may be parallel to the aiming or positioning axis.

FIG. 4 depicts a first eyepiece 61 containing focusing optics and an optical combiner 71 with a splitter cube. The focusing optics form an image from the microdisplay 50 to infinity that is superimposed onto the external landscape by a light combiner 71. Light combiner 71 includes an inclined planar semi-reflective plate 711 and two planar and parallel surfaces 712 and 713. As in the example, the focusing optics of FIG. 4 includes three lenses 610, 611 and 612 and a plane return mirror 613 located between the second and third lenses. This mirror 613 allows the bulk of the focusing optics to be reduced. In an alternative embodiment, the mirror can be replaced by a total internal reflection prism. In this configuration depicted in FIG. 4, the light combiner 71 reflects the image directly from the display to the viewer's eye Y.

FIG. 5 depicts a second eyepiece 62 containing focusing optics and an optical combiner 72 with a splitter cube. In this configuration, the optical combiner has optical power in the path of the microdisplay. Optical combiners have no optical power on the direct transmission path. Therefore, the number and size of lenses required for collimation is reduced. Eyepieces are simpler and less bulky.

Splitter cube 72 then includes a reflective concave mirror 722 whose optical axis is perpendicular to the aiming axis. Collimation of the light rays from the display 50 is ensured by a group of three lenses 620 , 621 and 622 and by a combiner 72 . The light rays from the video microdisplay 50 pass through a group of lenses, are transmitted by a semi-reflective plate 721, are reflected by a concave mirror 722, and are then reflected again by the semi-reflective plate 721 towards the viewer's eyes.

In this optical combination, as in the previous combination, the plane return mirror 623 allows the optical bulk of the eyepiece to be reduced. In an alternative embodiment, the splitter cube includes a convex input surface 723 whose optical axis is perpendicular to the aiming or positioning axis and opposite the concave mirror 722 . The function of this convex surface 723 is to avoid visible total internal reflections that originate from the scene and are reflected by total internal reflection on this side of the prism. This convex surface makes it possible to defocus these false images and push them back into the invisible zone at the firing position.

In a second embodiment shown in FIG. 6, the optical combiner 73 includes a "free-form" or diffractive type concave semi-reflective surface tilted with respect to the aiming or positioning axis. A "free-form" surface is understood to mean a surface that has no rotational symmetry. It can be defined in various ways.

In this configuration, the semi-reflective surface is tilted to the optical axis at a significant angle, which may be about 40 degrees. In this case, the eyepiece 63 includes a convex mirror 632 that is similarly tilted to the optical axis relative to the concave semi-reflective surface 73, as can be seen in FIG. This mirror may also be a "free-form" or diffractive type surface. Finally, the eyepiece 63 includes a group of two lenses 630 and 631 forming a pair, a convex mirror 632, and a concave semi-reflective surface 73. If the group of lenses has a significant focal length, an optical beam folding device, which may be mirror-based or prism-based, can be placed between the display 50 and this group of lenses to reduce the bulk of the eyepiece. be.

In an important variant embodiment of the aiming and spotting scope according to the invention, the scope comprises a luminous symbol or dot and an optical system arranged to superimpose the image of the luminous symbol or dot on the image of the video microdisplay and on the external landscape. equipment. The optical device then includes a splitter plate or splitter cube placed in front of the video microdisplay, whereby the image of the luminescent symbols or dots is combined with the video microdisplay by reflection or transmission by the splitter plate or splitter cube. be done.

In its basic version, the light-emitting dots are generated by light-emitting diodes placed in front of a perforation, which is placed in the focal plane of the eyepiece so as to be superimposed on the microdisplay image. This dot is generally red in color. The luminous dot is fixed on a translational adjustment mechanism in the focal plane to enable the user to perform muzzle aiming adjustment of the aiming axis embodied by the luminous dot with respect to the firing axis of the weapon. be done. The display reticle and the red dot constitute two alternative solutions for indicating the weapon's aiming axis, the red dot being a simple solution with very low consumption. Video reticles make it possible, for example, to generate patterns of various sophisticated shapes, including optical ranging symbols of people or vehicles, ensuring proper distance measurement.

The "red" dot therefore constitutes an optional supplement to the video microdisplay. It also enables a low consumption reduced mode when the microdisplay and thermal image are not operating, for example to save electrical energy of the scope.

A first example of the implementation of this variant embodiment is represented in FIG. A splitter cube 90 including a planar semi-reflective plate 91 is placed between the microdisplay 50 and the first lens of the eyepiece. The eyepiece has the configuration of eyepiece 60 of FIG. The red dot 95 is arranged such that its image is coupled to the microdisplay by reflection on the semi-reflective plate 91.

A second exemplary embodiment is depicted in FIG. In this example, eyepiece 64 includes an optical component 640 positioned between microdisplay 50 and splitter cube 900. An identical optical component 640bis is also placed between the red dot 95 and the splitter cube 900. The splitter cube is an assembly of two prisms 901 and 902, whose common surface 910 includes a semi-reflective treatment. In the case of FIG. 7, prism 902 operates by total internal reflection. The eyepiece part therefore comprises in this order optical components 640 and 640bis, a splitter prism 900, a total reflection prism 641 ensuring beam folding, a semi-reflection plate 73 and a pair 642.

Note that it is easily possible to adapt the eyepiece with the free-form plate of FIG. 6 to provide the production of a red dot. For this purpose, it is sufficient to place a splitter cube or any other prism assembly between the microdisplay and the lens.

A sighting scope according to the invention may include a complementary modular optical system that allows the perception of the external landscape to be modified. It is therefore possible to place a magnifying afocal optic with a magnification of eg 3 downstream of the optical combiner. It is likewise possible to place an optical module upstream of the combiner that is invariant with respect to magnification and light intensification axis deflection. The user thus perceives both an enhanced image and a thermal image of the external landscape.

The first advantage of the scope according to the invention is that it adds decamouflage capability to the illuminated sight for daytime aiming, while providing a large eye print, which does not obscure peripheral vision, and which allows the user to keep both eyes open. The aim is to preserve the ergonomic qualities of the illuminated sight that allow it to capture the target. The user has a directional image of the scene in the sight window, and on the directional image, on the one hand, there is an optical reticle embodying the firing axis of the weapon, and on the other hand, the directional image of the scene that is present in the scene and may pose a threat. A video image of a hot target is superimposed. Exclusive display of hot targets of human body temperature by removing the background of the scene is ensured by conventional algorithms used in thermal imaging, especially in IL/IR fusion systems. These algorithms are well known to those skilled in the art. Thus, the combatant benefits from a combined field of view between the direct view of the scene and the thermal infrared vision of the target, which also allows the combatant to direct the weapon's axis of fire when aiming at this target. A light reticle appears.

The second advantage of this scope is the way it can be done at night with an illuminated sight, i.e. 1 magnification, large eye print, and ergonomics of aiming with both eyes open, rather than a traditional thermal imaging sighting scope. The purpose is to enable infrared aiming.

A third advantage is that at night, a combatant is able to see with illuminated sights by using light-enhanced night vision glasses that may be provided to the combatant; is fixed on the combatant's head or on his headset and thus held in front of the combatant's eyes. Second, warfighters benefit from the perception of night scenes over a wide field of view, the field of view of night vision glasses. This field of view is typically 40°. Additionally, combatants benefit from infrared vision of the scene around the reticle that defines their aiming axis. The warfighter then benefits from both situational awareness through night vision glasses that provide a wide field of view that he or she can use with both eyes open, and images of the target that are decamouflaged in thermal infrared light.

Thus, the warfighter has at his disposal a dual image combination system: direct and thermal infrared vision during the day, light enhancement, and thermal infrared at night. This is effective without the addition of specific night vision glasses, simply by using the night vision glasses already available in the military. This dual benefit from a single lightweight, compact module means that it has illuminated sight-type ergonomics that allow for quick aiming while keeping both eyes open during the day as well as at night, while each Added to the advantage of having a good perception of the environment at the moment, and this perception being beneficial in dynamic combat situations and for responsiveness that allows gaining the upper hand in combat situations.

Claims (11)

A camera (10),
a video microdisplay (50) for displaying images from the camera (10) ;
a luminous symbol or dot (95);
In a sighting or spotting scope comprising in a single mechanical structure (80) an optical device (90) arranged to superimpose an image of said luminescent symbol or dot on an image of a video microdisplay , the eyepiece a device (90), at least one group of lenses, a return mirror and a light combiner (70) arranged to superimpose an image of said video microdisplay and an image or dot of said luminescent symbols on an external landscape; In this order , include
A luminous symbol or dot is located in the focal plane of the eyepiece and provides an aiming axis;
Aiming or Spotting The scope allows the user to aim the muzzle of the sighting axis relative to the firing axis of the weapon such that the position of the luminous symbol or dot (95) is adjustable in translation in the focal plane of the eyepiece. is configured to perform adjustments;
Aiming or spotting scope is
- a mode in which the video microdisplay is powered on and configured to display at least the reticle and the luminous symbol or dot (95) is powered off;
- Low consumption reduced mode where the camera and video microdisplay are powered off while the luminous symbol or dot (95) is powered on.
A sighting or spotting scope, characterized in that it is configured to operate in different modes, including : 2. An optical chain consisting of the camera, the microdisplay and the eyepiece has a magnification of 1, and the image of the microdisplay corresponds to the image of the external landscape. Aiming or spotting scope as described. A sighting or spotting scope according to claim 1 or 2, characterized in that the light combiner comprises a planar semi-reflective surface (71 1) inclined at 45 degrees to the sighting or spotting axis. A aiming or spotting scope according to claim 3, characterized in that the semi-reflective surface is incorporated into a splitter plate comprising two planar and parallel surfaces. A aiming or spotting scope according to claim 3, characterized in that the semi-reflective surface is incorporated into a splitter cube (71, 72) comprising two planar and parallel surfaces. The splitter cube includes a reflective concave mirror (722), the optical axis of the reflective concave mirror (722) is perpendicular to the aiming or spotting axis, and the light rays from the video microdisplay are transmitted by the semi-reflective surface. 6. A sighting or spotting scope as claimed in claim 5, characterized in that it is reflected by the concave mirror and then by the semi-reflective surface. The splitter cube comprises a convex input surface (723), the optical axis of the convex input surface (723) being perpendicular to the aiming or spotting axis and opposite the concave mirror. The aiming or spotting scope described in item 6. said optical combiner comprises a "free-form" or diffractive type concave semi-reflective surface ( 73) tilted with respect to said aiming or spotting axis; and said eyepiece is associated with said concave semi-reflective surface. A aiming or spotting scope according to claim 1 or 2, characterized in that it comprises a convex mirror (632). The optical device includes a splitter plate or splitter cube (90) placed in front of the video microdisplay, so that the image of the luminescent symbols or dots is reflected or transmitted by the splitter plate or the splitter cube. A aiming or spotting scope according to claim 1, characterized in that it is coupled with the video microdisplay by. A sighting or spotting scope according to any one of claims 1 to 9, characterized in that the camera is a thermal infrared camera. A aiming or spotting scope according to any one of claims 1 to 9, characterized in that the camera is a low light level camera.

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