EP3649425A1

EP3649425A1 - Aiming scope with illuminated sights and thermal imaging camera

Info

Publication number: EP3649425A1
Application number: EP18733916.3A
Authority: EP
Inventors: Jean-Luc Espie; Bruno Coumert
Original assignee: Thales SA
Current assignee: Thales SA
Priority date: 2017-07-06
Filing date: 2018-07-03
Publication date: 2020-05-13
Anticipated expiration: 2038-07-03
Also published as: CN110832266A; CA3068772A1; AU2018297577B2; WO2019007973A1; FR3068776B1; JP2023164827A; JP7393951B2; FR3068776A1; JP2020525849A; EP3649425B1; SG11202000034XA; AU2018297577A1

Abstract

The general field of the invention is that of sighting or spotting scopes including, in a single mechanical structure (80), a camera (10) and a video microdisplay (50) in association with an eyepiece (60). The eyepiece of the scope according to the invention includes an optical combiner (70) that is arranged so as to superpose the image of the video microdisplay over the outside landscape. In one variant, the scope includes a luminous symbol or dot (95) and an optical device (90) that is arranged to superpose the image of said luminous symbol or dot over said image of the video microdisplay and over the outside landscape. The optical chain consisting of the camera, the microdisplay and the eyepiece has a magnification of one, the image of the microdisplay conforming to that of the outside landscape.

Description

Clear viewfinder and thermal camera

The field of the invention is that of shooting glasses comprising a thermal camera and a clear viewfinder.

To accomplish his various missions with his armament, the infantryman has the following needs:

- Shooting capacity of day and night, requiring a precise aim to exploit the best weapon, ideally for effective fire beyond 300 meters;

Rapid aiming in dynamic combat situation;

Maintaining a good situational awareness to deal with any threat that may arise on the battlefield, day or night. This awareness of the situation includes the preservation of a wide field of vision embracing the surrounding space;

Ability to "tangle" or perceive threats, day or night;

Discretion, which is reflected in particular at night by the absence of light emission of the sighting devices;

No need for a simbleagle adjustment operation to switch from daytime to nighttime and vice versa, to save time and ensure reliable sighting;

Mobility and endurance, which requires equipment as light and compact as possible.

These needs translate into strong demands on the sighting devices on the assault rifle that the infantryman is equipped with. In practice, these requirements are only partially satisfied and are not satisfied with a single piece of equipment that is both compact and lightweight.

Common solutions for aiming on an assault rifle are as follows. For daytime sighting, the weapon has a basic eyepiece - handlebar assembly. This set is simple, robust and low cost, but offers little precision. The weapon may also include for day sighting:

a clear viewfinder, that is to say an optical assembly for superimposing on the outside a symbol or a point of light in the line of sight. This clear viewfinder can be associated possibly with a switchable magnifying optics. For example, the magnification is 3;

A laser pointer;

A magnifying glass by day;

For night sighting, the weapon may include:

- a laser pointer;

A light intensifying fire sight called "IL"; An infrared rifle scope called "IR";

An adapter or "clip-on" light intensifier or infrared positioned upstream of a rifle scope;

An aiming device comprising night vision binoculars associated with a clear viewfinder secured to the weapon.

These known solutions each have advantages and disadvantages, but none completely meets the global need identified above.

The clear viewfinder solution is particularly appreciated because it offers good accuracy, while preserving a good perception of the overall situation in that it allows aiming and firing with both eyes open and that it allows a position of light. relatively distant eye from the clear viewfinder optics, the eye not being close to an eyepiece. The shooter can keep both eyes open, the clear viewfinder transmitting the landscape without magnification.

The aiming with a laser pointer, widely used, especially at night, is very interesting because it allows a quick shot in dynamic combat, without the need to align the eye behind a viewfinder, or even to support the weapon in extreme situation. On the other hand, the laser pointer remains indiscreet, especially at night. Even when it is a pointer emitting in the near infrared, it is easily detectable with night vision binoculars or even with some equipment using a sensitive camera in the near infrared.

Shooting goggles in general, whether they are daytime goggles or night goggles, with intensification of light or with thermal infrared, have the advantage of their precision, thanks in particular to their magnification. They have the disadvantage of imposing to position the eye used for the near sight of an eyepiece; moreover, the user can not use the other eye for an overall perception. This operation takes a while, which is a loss of efficiency in dynamic combat. In addition, the shooter temporarily shuts down his environment and can ignore new threats. Finally, at night, if equipped with a night vision binocular, the fighter must clear it to be able to correctly position a free eye behind the riflescope. Again, this represents an additional delay in action and a break with the fighter's environment.

Infrared or thermal goggles have the same drawbacks but offer some significant advantages: night vision, even in total darkness, improved vision in the mists and smokes of the battlefield and above all the ability to "dechume" any hot target .

To try to provide an appropriate response, it is possible to juxtapose in a single device several systems. For example, as seen in Figure 1, some sighting equipment include a rifle scope IL or IR surmounted by a clear viewfinder. In this case, the telescope comprises a thermal camera and a display device. The thermal camera includes a focusing lens 1 and a photosensitive receiver 2. The display device comprises a micro-display 3 and an eyepiece 4. The clear viewfinder comprises a light symbol 5 and a collimating optics 6 and superposition with the vision direct 7.

These solutions lead to relatively bulky equipment that offers a juxtaposition of functions without combining them. At any given moment, the user must choose to use either the clear viewfinder or the telescope and therefore never benefit from the cumulative advantages of both systems. In the case of a system associating an infrared telescope With a clear viewfinder, the user must choose between taking advantage of the quick view and the awareness of the situation offered by the clear viewfinder, or benefit from the dechilation and night vision offered by the thermal telescope.

In summary, existing solutions based on a single principle of clear viewfinder type, pointer or telescope do not meet all the needs of the infantryman for shooting in any situation. Solutions that juxtapose two principles in the same equipment, such as a clear viewfinder and a thermal telescope, allow you to combine certain advantages without being able to benefit from them simultaneously. Moreover, these systems are bulky and heavy. They do not fully meet the needs identified above. The bezel according to the invention does not have the above disadvantages. Indeed, several images from different sources are perceived by a single eyepiece type clear viewfinder. This ensures many of the requirements of this type of equipment while maintaining a small footprint. More specifically, the subject of the invention is a sighting or observation telescope comprising, in a single mechanical structure, a camera and a video micro-display associated with an eyepiece, characterized in that the eyepiece comprises an arranged optical combiner. in order to superimpose the image of the video micro-display on the outside landscape.

Advantageously, the telescope comprises a dot or a light symbol and an optical device arranged to superimpose the image of said dot or said light symbol on said image of the video micro-display and on the outside landscape.

Advantageously, the optical system consisting of the camera, the micro-display and the eyepiece has a unitary magnification, the image of the micro-display being in accordance with that of the external landscape.

Advantageously, the optical combiner comprises a flat semi-reflecting surface inclined at about 45 degrees on a line of sight or observation.

Advantageously, the semi-reflecting surface is integrated with a separating plate comprising two plane and parallel faces. Advantageously, the semi-reflecting blade is integrated in a separator cube comprising two plane and parallel faces. The normal to said faces may be parallel to the line of sight or observation.

Advantageously, the separating prism comprises a reflecting concave mirror whose optical axis is perpendicular to the line of sight or observation, the light rays coming from the video micro-display being transmitted by the semi-reflecting plate, reflected by the mirror. concave then by the semi-reflective blade.

Advantageously, the separating prism comprises a convex input face whose optical axis is perpendicular to the line of sight or observation and opposite to the concave mirror.

Advantageously, the optical combiner comprises a concave semi-reflective surface of freeform or diffractive type inclined on the line of sight or observation and the eyepiece comprises a convex mirror associated with the concave semi-reflecting surface.

Advantageously, the optical device comprises a separating plate or a splitter cube disposed in front of the video micro-display so that the image of the point or of the light symbol is, by reflection or transmission by the separating plate or by the splitter cube, confused with the video micro-display.

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

The invention will be better understood and other advantages will become apparent on reading the description which follows given by way of non-limiting example and by virtue of the appended figures among which:

The already commented FIG. 1 represents a combined clear viewfinder bezel according to the prior art;

FIG. 2 represents a perspective view of a sighting or observation telescope according to the invention;

FIG. 3 represents a diagram of embodiment of a telescope of observation or observation according to the invention;

FIG. 4 represents a first embodiment of an eyepiece according to the invention; FIG. 5 represents a second embodiment of an eyepiece according to the invention;

FIG. 6 represents a third embodiment of an eyepiece according to the invention;

FIG. 7 represents an alternative embodiment of a sighting or observation telescope according to the invention comprising the generation of a collimated light point;

FIG. 8 represents a fourth embodiment of an eyepiece according to the invention.

FIG. 2 represents a perspective view of a sight and observation telescope according to the invention. It essentially comprises two main subsets which are a camera 10 and a display device 15 comprising a micro-display and an optical combiner eyepiece. The optical combiner is mounted above the camera. The set of optical and electronic components is integrated in a sealed structure 80 which protects them from the external environment and shocks.

This structure has a mechanical interface 85 fixing for fixing on a weapon equipped with a standard interface. This interface is, for example, a "Picatinny" rail or its equivalent.

The structure also comprises a set of 87 buttons and control members allowing in particular the on / off commands of the various functions of the equipment, the brightness settings of the micro-video display, the electronic and mechanical settings of the simbleautage, the settings electronic superposition of different images generated on the outdoor landscape. It can be arranged on one of the two lateral sides of the telescope. For example, in Figure 2, the assembly comprises three buttons arranged on the left lateral flank of the bezel, other buttons being arranged on the left side of the bezel.

FIG. 3 represents a first embodiment of a sighting or observation telescope according to the invention. For this figure and the following, the following conventions have been adopted. The optical or mechanical elements are represented in bold lines, the light rays are represented in fine lines and the optical axes in dashed lines. For the sake of clarity, only the light rays on the optical axis are represented. The camera is preferably a thermal camera, consisting of an infrared lens 20 operating in the spectral band located between 8pm and 12pm and an infrared sensor 25 with sensitive micro-bolometers in the same spectral band.

The camera can also be a low light level camera using a low noise "CMOS" sensor, "CMOS" being the acronym for "Complementary Metal Oxide Semi-conductor" or an "EB-CMOS" sensor, acronym of "Electro-Bombarded CMOS". The camera can also be a "SWIR" camera, an acronym for "Short Wave InfraRed" operating in the spectral band between 1 pm and 2 pm, capturing the nocturnal light resulting from the nocturnal luminescence or "night glow" and also offering decoupling capabilities .

This camera comprises a power electronics, sensor control and image processing and a power supply unit 40 receiving several batteries or a rechargeable battery pack so as to ensure its autonomy that can be arranged to the back of the telescope, the observer's eye side.

The display device comprises a micro-display 50, an eyepiece 60 with an optical combiner 70 and the electronics necessary for feeding and controlling the micro-display.

This micro-display 50 displays a target video reticle, optionally enriched with rising correction elements or stadia symbols or graduations. It also displays the thermal infrared image of the scene from the thermal camera.

This micro-display can be, for example, a display

"OLED", an acronym for "Organic Light Emmitting Diode", an acronym for "Liquid Crystal Display", an "LCOS" sign, an acronym for "Liquid Crystal On Silicon". The optical system consisting of the camera, the micro-display and the eyepiece has a unit magnification, the image of the micro-display being in accordance with that of the external landscape. The optical combiner ensures the perfect superposition of the image of the micro-display on the external landscape.

The optical combiner eyepiece has different possible embodiments.

In a first embodiment illustrated in Figures 4, 5 and 8 which represent different optical combinations of eyepiece, the optical combiner has a flat semi-reflecting surface inclined at 45 degrees on a line of sight or observation. This surface has no optical power.

This surface may belong to a semi-reflective plate with flat and parallel faces of small thickness as can be seen in FIG.

As illustrated in FIGS. 4 and 5, this blade can advantageously be integrated into a separator cube comprising two plane and parallel faces so as not to introduce distortion on the external landscape. Normal to these faces may be parallel to the line of sight or observation.

FIG. 4 represents a first eyepiece 61 comprising focusing optics and an optical combiner 71 with a separator cube. The focusing optics forms a micro-display 50 an infinite image which is superimposed on the outside landscape by means of the optical combiner 71. The optical combiner 71 comprises an inclined semi-reflective flat plate 71 1 and two plane and parallel faces 712 and 713. By way of example, the focusing optics of FIG. 4 comprise three lenses 610, 61 1 and 612 and one plane reflecting mirror 613 located between the second and the third lens. This mirror 613 reduces the size of the focusing optics. In an alternative embodiment, the mirror can be replaced by a right prism. In this configuration shown in Figure 4, the optical combiner 71 directly reflects the image of the display to the eye Y of the observer.

FIG. 5 represents a second eyepiece 62 comprising focusing optics and an optical combiner 72 with separator cube. In this configuration, the optical combiner has optical power on the micro-display channel. The optical combiner has no optical power on the direct transmission path. Thus, the number and the size of the lenses necessary for collimation are reduced. The eyepiece is simpler and less bulky.

The separator cube 72 then comprises a reflecting concave mirror 722 whose optical axis is perpendicular to the line of sight. The collimation of the light rays coming from the display 50 is ensured by a group of three lenses 620, 621 and 622 and by the combiner 72. The light rays issuing from the video micro-display 50 pass through the group of lenses, are transmitted by the semi-reflecting plate 721, reflected by the concave mirror 722 and a second time by the semi-reflecting plate 721 to the observer's eye.

In this optical combination as in the previous one, a plane reflecting mirror 623 makes it possible to reduce the optical bulk of the eyepiece. In an alternative embodiment, the separator cube comprises a convex entry face 723 whose optical axis is perpendicular to the sighting or observation axis and opposite to the concave mirror 722. This convex face 723 has the function of avoid the total reflections seen by the eye that come from the scene and are reflected by total reflection on this face of the prism. This convex face makes it possible to defocus these parasitic images and to push them back into an area not visible to the eye in firing position.

In a second embodiment illustrated in FIG. 6, the optical combiner 73 comprises a concave half-reflective surface of freeform or diffractive type inclined on the line of sight or observation. The term "freeform" surface or free form, a surface that has no symmetry of revolution. It can be defined in different ways.

In this configuration, the semi-reflecting surface is inclined on the optical axis by a large angle which may be close to 40 degrees. In this case, the eyepiece 63 comprises a convex mirror 632 also inclined on the optical axis associated with the concave semi-reflecting surface 73 as can be seen in FIG. 5. This mirror can also be a "freeform" type surface or diffractive. In the end, the eyepiece 63 comprises a group of two lenses 630 and 631 forming a doublet, the convex mirror 632 and the concave semi-reflecting surface 73. lenses has a large focal length, it is possible to interpose between the display 50 and this group of lenses an optical device for folding the beams which can be mirror or prism so as to reduce the size of the eyepiece.

In an important embodiment of the telescope and observation telescope according to the invention, the telescope comprises a point or a luminous symbol and an optical device arranged to superpose the image of this point or of this luminous symbol on the image of the micro-video display and on the outdoor landscape. The optical device then comprises a splitter plate or a splitter cube disposed in front of the video micro-display so that the image of the point or of the light symbol is, by reflection or transmission by the separating plate or by the splitter cube, coinciding with the micro-video display.

In its basic version, the light point is made by means of a light-emitting diode placed in front of a source hole, the latter being positioned in the focal plane of the eyepiece so as to be superimposed on the image of the micro-display. This point is usually red. The luminous point is fixed on a translation adjustment mechanism in the focal plane so as to allow the user to make adjustments of the alignment of the line of sight materialized by the luminous point with respect to the axis of fire of the weapon. The reticle of the display and the red dot are two alternative solutions to materialize the line of sight of the weapon, the red dot being a simple solution with very low consumption. The video reticle allows generating patterns of diverse and sophisticated shapes including, for example, stadia symbols of characters or vehicles providing approximate telemetry.

The "red" point is therefore an optional supplement to the video micro-display. It also allows a low-power degraded mode when the micro-display and the thermal image are out of operation, for example to save the electrical energy of the telescope.

A first exemplary embodiment of this variant embodiment is shown in FIG. 7. A separator cube 90 comprising a flat semi-reflecting plate 91 is disposed between the micro-display 50 and the first lens of the eyepiece. It has the configuration of the eyepiece 60 of Figure 3. The red dot 95 is arranged so that its image, by reflection on the semi-reflective plate 91 is confused with the micro-display.

A second exemplary embodiment is shown in FIG. 8. In this example, the eyepiece 64 comprises an optic 640 disposed between the micro-display 50 and the separator cube 900. An identical optic 640bis is also arranged between the red dot 95 and the separator cube 900. The separator cube is an assembly of two prisms 901 and 902 whose common face 910 comprises the semi-reflective treatment. In the case of Figure 7, the prism 902 works by total reflection. The ocular portion therefore comprises in this order the optics 640 and 640 bis, the separating prism 900, a right prism 641 which ensures the folding of the beams and the semi-reflecting plate 73 and the doublet 642.

It should be noted that one can easily adapt the eyepiece freeform blade of Figure 6 so as to introduce the generation of the red dot. To this end, it is sufficient to have a separator cube or any other prismatic assembly between the micro-display and the lens.

The aiming telescope according to the invention may comprise complementary modular optical systems making it possible to modify the perception of the external landscape. Thus, it is possible to have downstream of the optical combiner a magnifying afocal optic with a magnification of 3 for example. In the same way, an invariant optical module in terms of magnification and axis deviation with a light intensifier can be arranged upstream of the combiner. The user thus perceives both an intensified image and a thermal image of the external landscape.

The first advantage of the telescope according to the invention is, for the aim of day, to add a decamouflage ability to a clear viewfinder, retaining the ergonomic qualities of the clear viewfinder that offers a large eye, n'occculte not the peripheral field of vision and allows to engage a target by keeping both eyes open. The user has in the window of the viewfinder the direct image of the scene on which is superimposed on the one hand the light reticle materializing the axis of fire of his weapon, and on the other hand the video image of the hot targets present in the scene and likely to constitute threats. The display of hot targets only, at the temperature of human bodies by erasing the back of the scene is provided by conventional algorithms used in thermal imaging, especially in IL / IR fusion systems. These algorithms are known to those skilled in the art. The combatant thus benefits from a fused vision between the direct vision of the scene and the thermal infrared vision of the target, on which appears the luminous reticle representing the firing axis of the weapon when the fighter targets this target.

The second advantage of this telescope is to allow, at night, an infrared sighting, as an example of what can be done with a conventional thermal goggle, but with the ergonomics of a clear viewfinder: magnification 1, large eye drawn, aimed at two open eyes.

The third advantage is to allow the fighter to watch in the clear viewfinder at night by using the light-intensifying night-vision binoculars that he can be equipped with, which is fixed on his head or helmet and thus held in front of his eyes. . The fighter then benefits from the perception of the night scene on a wide field, that of the night vision binoculars. This field is typically 40 °. In addition, the fighter benefits from the infrared vision of the scene around the reticle, which defines its line of sight. He then has both the awareness of the situation thanks to the night vision binocular offering a wide field that can use both eyes open, and the image of the target dechumed in thermal infrared.

The fighter therefore has at his disposal a double image fusion system: direct vision and thermal infrared day, intensification of light and thermal infrared night. This is effective without adding a specific night vision binocular but simply by using the night vision binocular already in staffing in the armed forces. This double benefit, obtained from a single, lightweight and compact module, adds to the advantage of having, day and night, a clear viewfinder-type ergonomics that allows for fast aiming, two open eyes, by maintaining at each moment a good perception of the environment, profitable for the reactivity in dynamic combat situation and allowing to obtain the superiority in situation of duel.

Claims

1. A sighting or observation telescope comprising, in a single mechanical structure (80), a camera (10) and a video micro-display (50) associated with an eyepiece (60), characterized in that the eyepiece comprises, in this order, at least one lens group, a mirror and an optical combiner (70) arranged to superimpose the image of the video micro-display on the outdoor landscape.

2. A sighting or observation telescope according to claim 1, characterized in that the telescope comprises a point or a light symbol (95) and an optical device (90) arranged to superpose the image of said point or said light symbol on said image of the video micro-display and on the outdoor landscape.

3. Scope of view or observation according to one of the preceding claims, characterized in that the optical chain consisting of the camera, the micro-display and the eyepiece has a unit magnification, the image of the micro-display conforming to that of the external landscape.

4. Sighting or observation telescope according to one of the preceding claims, characterized in that the optical combiner comprises a plane semi-reflecting surface (71 1, 721) inclined at about 45 degrees on a line of sight or observation.

5. A sighting or observation telescope according to claim 4, characterized in that the semi-reflecting surface is integrated with a separating plate (73) having two flat and parallel faces.

6. Scope or sight according to claim 4, characterized in that the semi-reflecting surface is integrated in a separator cube (71, 72) having two flat and parallel faces.

7. Sighting or observation telescope according to claim 6, characterized in that the separator cube comprises a reflecting concave mirror (722) whose optical axis is perpendicular to the line of sight or observation, the light rays from the video micro-display being transmitted by the semi-reflecting plate, reflected by the concave mirror and the semi-reflective blade.

Sighting or observation telescope according to claim 7, characterized in that the separator cube comprises a convex entrance face (723) whose optical axis is perpendicular to the axis of sighting or observation and opposite. to the concave mirror.

9. Scope of view or observation according to one of claims 1 to 3, characterized in that the optical combiner comprises a concave semi-reflective surface (73) of the "freeform" or diffractive type inclined on the line of sight or of observation and in that the eyepiece comprises a convex mirror (632) associated with the concave semi-reflecting surface.

10. A sighting or observation telescope according to one of claims 2 to 9, characterized in that the optical device comprises a separating plate or a separator cube (90) arranged in front of the video micro-display so that the image of the point or the light symbol is, by reflection or transmission by the separating blade or the separator cube, confused with the video micro-display.

1 1. Sighting or observation telescope according to one of the preceding claims, characterized in that the camera is a thermal infrared camera.

Sighting or observation telescope according to one of claims 1 to 10, characterized in that the camera is a low light level camera.