Improved sighting or observation scope

Abstract

Sighting or observation scope (10) having a sighting or observation axis and comprising, in a mechanical structure (SM): a camera (CI), a first video micro-display (MA1) displaying an image of the exterior landscape acquired by the camera, called the first object, an eyepiece (OC) associated with the first video micro-display and forming a first image of the first object at infinity, a second video micro-display (MA2) displaying a second object, an optical combining device (SC) optically arranged downstream of the eyepiece and is adapted to form an image at infinity of the second object, called the second image, and to superimpose the first and second images on the exterior landscape. [Fig. 3B]

Description

Title of the invention: Improved sighting or observation scope Technical field

[0001] The field of the invention is that of shooting glasses, in particular reflex sights, which make it possible to superimpose a reticle on the observed scene. Prior art

[0002] To accomplish his various missions with his weaponry, the infantryman has the following needs: - Day and night shooting capability, requiring precise aiming to make the most of your weapon, ideally for effective shooting beyond 300 meters; - Fast aiming in dynamic combat situations; - Maintaining good situational awareness to deal with any threat that may arise on the battlefield, day or night. This situational awareness includes maintaining a wide field of vision encompassing the surrounding area; - Ability to “decamouflage” or perceive threats, day and night; - Discretion, which is reflected in particular at night by the absence of light emission from the sighting devices; - No need for sight adjustment operation to switch from day to night sighting and vice versa, to save time and ensure sighting reliability; - Mobility and endurance, which requires equipment that is as light and compact as possible.

[0003] These needs translate into high demands on the sights equipping the assault rifle with which the infantryman is equipped. In practice, these requirements are only partially met and are not met with a single piece of equipment that is both compact and lightweight.

[0004] Current solutions for aiming on an assault rifle are as follows. For daytime aiming, the weapon basically has an iron sight - front sight set. This set is simple, robust, and low - cost, but offers little precision.

[0005] The weapon can also have for daytime aiming a red dot sight (or "reflex"), that is, an optical assembly allowing to superimpose on the outside a symbol or a luminous point on the aiming axis. This red dot sight can optionally be associated with a switchable magnifying optic. It can further have a laser pointer and a daytime magnifying eyepiece.

[0006] For night aiming, the weapon may include: a laser pointer, a light-intensified shooting scope known as "IL", an infrared shooting scope known as "IR", an adapter or "Clip-on" with light intensifier or infrared positioned upstream of a daytime shooting scope, a sighting device comprising night vision binoculars associated with a clear sight attached to the weapon.

[0007] These known solutions each have advantages and disadvantages, but none of them completely meets the overall need identified above.

[0008] The clear viewfinder solution is particularly appreciated because it offers good precision, while preserving a good perception of the overall situation, the clear viewfinder transmitting the landscape without magnification.

[0009] Aiming using a laser pointer, widely used, especially at night, is very interesting because it allows rapid shooting in dynamic combat, without requiring the eye to be aligned behind a sight, or even to shoulder the weapon in extreme situations. 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 certain equipment using a camera sensitive in the near infrared.

[0010] Shooting scopes in general, whether day or night, light intensification or thermal infrared, have the advantage of their precision, thanks in particular to their magnification. They have the disadvantage of requiring the eye used for aiming to be positioned close to an eyepiece; moreover, the user cannot use the other eye for overall perception. This operation takes a certain amount of time, which constitutes a loss of effectiveness in dynamic combat. In addition, the shooter is momentarily cut off from his environment and can then ignore new threats. Finally, at night, if he is equipped with night vision binoculars, the combatant must clear them to be able to correctly position a free eye behind the shooting scope. Here again, this represents an additional delay in the action and a break from the combatant's environment.

[0011] Infrared or thermal shooting glasses have the same disadvantages but offer some significant advantages: night vision, including in total darkness, improved vision in the fog and smoke of the battlefield and above all the ability to "decamouflage" any hot target.

[0012] To try to provide a suitable response, it is possible to juxtapose several systems in a single piece of equipment. For example, as seen in [Fig.l], some sighting equipment combines an IL or IR shooting scope topped with a clear viewfinder. In this case, the scope includes a thermal camera and a viewing device. The thermal camera includes a focusing lens 1 and a receiver photosensible 2. The display device includes a microdisplay 3 and an eyepiece 4. The bright visor includes a light symbol 5, a collimation optics 6, and a superposition optics (typically a beam splitter) with direct vision 7.

[0013] These solutions result in relatively bulky equipment that offers a juxtaposition of functions without actually combining them. At any given time, the user has to choose to use either the bright visor or the goggles and thus never benefits from the cumulative advantages of the two systems. In the case of a system combining a thermal infrared goggle and a bright visor, the user has to choose between benefiting from the quick sight and situation awareness offered by the bright visor, or benefiting from the camouflage breaking and night vision offered by the thermal goggle.

[0014] An improved solution is illustrated in [Fig.2]. The same references as those in [Fig.l] designate the same elements as those described in [Fig.l]. The architecture of [Fig.2] consists of combining an “advanced” reflex viewfinder architecture with a single display 3 which is responsible for displaying everything: video stream, symbology, reticle, etc. The image of the display is returned to infinity using an eyepiece 3. The fusion with the scene is done using a semi-reflecting plate 7.

[0015] The reflex sight with display of [Fig.2], coupled with a camera 2 with light intensification or infrared thus presents a real added value because it provides additional assistance for highlighting a target in difficult conditions (target camouflage, darkness, etc.) by compactly combining “night” and “day” vision.

[0016] The solution of [Fig.2], although presenting a clear improvement over the architecture of [Fig.l], nevertheless has a drawback. In the event of a malfunction of the display 3, all the video, symbology and reticle functions of the viewfinder are lost. In addition, the display necessarily has a high display rate in order to perform all the aforementioned functions (typically 20 Hz or more). This implies a significant power consumption of the display, which results in an autonomy of the viewfinder of [Fig.2] limited to a few hours. Once the batteries are used up, or the battery is empty, this reflex viewfinder no longer works, even for basic functions such as the display of a reticle.

[0017] In summary, existing solutions based on a single principle of the clear sight, pointer or scope type do not meet all the needs of the infantryman for shooting in all situations.

[0018] The invention aims to overcome some of the aforementioned problems of the prior art. To this end, an object of the invention is a sighting or observation telescope comprising in particular a camera, a first video micro-display displaying an image of the exterior landscape acquired by the camera and a second video micro-display. The use of two displays makes the sight of the invention more versatile and more robust. In addition, by selecting a micro-display with low power consumption compared to the other micro-display, the scope of the invention allows operation in a "degraded" mode via the display of a customizable red dot / reticle with a battery life of a few hundred hours. Thus, the user can extend his mission or when the capacity of the battery powering the sight drops below a critical threshold. Summary of the invention

[0019] For this purpose, an object of the invention is a sighting or observation telescope having a sighting or observation axis A and comprising, in a mechanical structure: - a camera, - a first video micro-display displaying an image of the exterior landscape acquired by the camera, called the first object - an eyepiece associated with the first video micro-display and forming a first image of the first object at infinity - a second video micro-display displaying a second object - an optical combining device optically arranged downstream of the eyepiece and is adapted to form an image at infinity of the second object, called the second image, and to superimpose the first and second images on the external landscape.

[0020] According to one embodiment, the second micro-display is a micro-display with low power consumption compared to the first micro-display.

[0021] Preferably, in this embodiment, the second micro-display has a refresh frequency less than or equal to 2 Hz, the first micro-display having a refresh frequency greater than or equal to 20 Hz.

[0022] Preferably, in this embodiment, the glasses comprise a battery powering the camera, the first and second video micro-displays and a processor, said processor being configured to operate the battery according to two distinct modes consisting of: - in a first mode, powering the first video micro-display and not powering the second video micro-display or powering the first and second micro-display when a battery capacity is greater than a predetermined limit or when the user chooses it, for example by pressing a remote control member on said mechanical structure, - in a second mode, power the second video micro-display and do not powering the first video micro-display when a battery capacity is lower than the predetermined limit, or when the processor detects a malfunction of the first display, or when the user chooses it, for example by pressing a remote control member on said mechanical structure.

[0023] Even more preferably, the predetermined limit corresponds to a battery life in the first operating mode of less than 1 hour of use.

[0024] According to one embodiment, the first micro-display emits radiation in a first spectral range and the second micro-display emits radiation in a second spectral range, separate from the first spectral range or the first and second micro-displays emit radiation in the same spectral range but having cross-polarization.

[0025] According to one embodiment, the optical combining device comprises: - a planar semi-reflecting surface inclined at approximately 45 degrees relative to the sighting or observation axis x or a surface comprising a dichroic treatment adapted to reflect a spectral range of the radiation emitted by the first micro-display, said planar semi-reflecting surface being adapted to carry out said superposition of the first and second images on the external landscape - a holographic or diffractive element or a metasurface arranged on the optical path of the rays coming from the second display and adapted to form said second image.

[0026] Preferably, the holographic or diffractive element or said metasurface has a holographic treatment and / or a structure specifically adapted to form an image of rays having a wavelength included in the second spectral range and adapted to transmit the first spectral range.

[0027] Preferably, the holographic or diffractive element or said metasurface is deposited or attached to the planar semi-reflective surface. Alternatively, the holographic or diffractive element or said metasurface is separated from the planar semi-reflective surface.

[0028] According to one embodiment, the optical combining device comprises: - a planar semi-reflecting surface inclined at approximately 45 degrees relative to the sighting or observation axis x, said planar semi-reflecting surface being adapted to carry out said superposition of the first and second images on the external landscape - a concave surface of the “freeform” or aspherical type inclined on the axis of x-ray sighting or observation and arranged on the optical path of the rays coming from the second display so as to form said second image.

[0029] According to one embodiment, the optical combining device comprises: - a flat semi-reflecting surface inclined at approximately 45 degrees relative to the sighting or observation axis A, said flat semi-reflecting surface being adapted to carry out said superposition of the first and second images on the exterior landscape - an additional eyepiece suitable for forming the second image, - a pupil expansion light guide arranged on the optical path of the rays coming from the second display and adapted to extend a pupil of the additional eyepiece in two directions of space while also participating in said superposition of the first and second images on the external landscape. Brief description of the drawings

[0030] Other characteristics, details and advantages of the invention will emerge on reading the description given with reference to the appended drawings given by way of example and which represent, respectively:

[0031] [Fig-1] a schematic view of a prior art rifle scope,

[0032] [Fig.2] a schematic view of a prior art rifle scope,

[0033] [Fig.3A] a perspective view of a sighting or observation scope according to the invention,

[0034] [Fig.3B]] a schematic view of a sighting or observation scope according to the invention,

[0035] [Fig.3C]] a perspective view of a sighting or observation scope according to a preferred embodiment of embodiment Ml of the invention,

[0036] [Fig.4] a schematic representation of an embodiment of the telescope of the invention,

[0037] [Fig.5] a schematic representation of an embodiment of the telescope of the invention,

[0038] [Fig.6] a schematic representation of an embodiment of the telescope of the invention,

[0039] In the figures, unless otherwise indicated, the elements are not to scale and identical references designate identical elements. Description of the embodiments

[0040] Figure 3A shows a perspective view of a riflescope or observation 10 according to the invention. Figure 3B is a schematic representation of the elements included in the mechanical structure SM of the sighting scope or observation device 1 according to the invention having an x ​​axis of sight or observation. The telescope 10 essentially comprises two main sub-assemblies which are a CI camera and a DV viewing device whose structure is detailed more precisely in [Fig.3B].

[0041] The viewing device DV comprises a first and a second microdisplay MAI, MA2, an eyepiece OC associated with the first display MAI and an optical combination device SC. For example, as illustrated in [Fig.3A], the optical combination device SC is mounted above the camera CI. Alternatively, the camera is above, or on the side of the optical combination device SC. All of the optical and electronic components are integrated into the sealed mechanical structure SM which protects them from the external environment and from shocks.

[0042] This SM structure includes a mechanical IF fixing interface allowing it to be fixed to a weapon equipped with a standard interface. This interface is, for example, a “Picatinny” rail or its equivalent.

[0043] The structure also includes a set IC of buttons and control members allowing in particular the On / Off controls of the various functions of the equipment, the brightness adjustments of the video micro-display MAI, MA2, the electronic and mechanical adjustments of simbleautage, the electronic adjustments of superposition of the various images generated on the external landscape. It can be arranged on one of the two lateral sides of the bezel. As a non-limiting example, in [Fig.3A], the set includes three buttons arranged on the left lateral side of the bezel, other buttons being arranged on the right side of the bezel.

[0044] According to one embodiment of the invention, the camera CI is a thermal camera, comprising an infrared objective OI operating in the spectral band located between 8 pm and 12 pm and an infrared sensor CPT sensitive in the same spectral band or between 3 and 5

[0045] Alternatively, according to another embodiment, the camera is a low light level camera implementing a low noise CPT “CMOS” sensor, “CMOS” being the acronym for “Complementary Metal Oxide Semi-conductor” or an “EB-CMOS” sensor, acronym for “Electro-Bombarded CMOS” or any other digital low light level camera.

[0046] The camera can also be a “SWIR” camera, acronym for “Short Wave InfraRed” operating in the spectral band between 1 pm and 2 pm, capturing night light from night luminescence or “night glow” and also offering decamouflage capabilities.

[0047] The CI camera includes electronics for power supply, sensor control and image processing as well as a power supply box (not shown) receiving several batteries or a rechargeable battery pack so as to ensure its autonomy which is for example placed at the rear of the telescope, on the observer's eye side.

[0048] The DV display device comprises the first video micro-display MAI, the eyepiece OC forming an image of the first video micro-display at infinity and the electronics necessary for powering and controlling the first micro-display.

[0049] The first micro-display MAI displays a video aiming reticle, possibly enhanced with elevation correction elements or symbols or stadimetric graduations. It also displays an image of the exterior landscape acquired by the camera, called the first object. RI denotes the radiation emitted by the first micro-display MAL. According to one embodiment, the first micro-display MAI only displays the image of the exterior landscape acquired by the camera.

[0050] The display device DV further comprises the second video micro-display MA2 and the optical combining device SC. The image displayed by the second video micro-display MA2 is called "second object" and the radiation emitted by the second micro-display MA2 is denoted R2.

[0051] The optical combining device SC is optically arranged downstream of the eyepiece OC and is adapted to form an image at infinity of the second object, called the second image, and to superimpose the first and second images on the external landscape. Different examples of optical combining devices SC are described later (see Figures 4 to 6).

[0052] The first and second video micro-displays MAI, MA2, are, by way of example, “OLED” displays, an acronym meaning “Organic Light Emitting Diode”, “LCD”, an acronym meaning “Liquid Crystal Display”, or “LCOS”, an acronym meaning “Liquid Crystal On Silicon”.

[0053] The use of two displays makes it possible to make the scope of the invention more versatile by combining several functions (for example a display relaying an IR image in a spectral band between 1 and 2 pm and another relaying a thermal image (in a spectral band between 2 and 15 pm). In addition, this makes the scope of the invention more robust, for example by allowing switching to the second micro-display during a malfunction of the first micro-display.

[0054] Furthermore, by selecting a micro-display with low power consumption compared to the other micro-display, the scope of the invention allows operation in a “degraded” mode via the display of a customizable red dot / reticule with a battery life of a few hundred hours. Thus, the user can extend his mission or when the capacity of the battery powering the sight drops below a critical threshold.

[0055] More specifically, according to a first embodiment M1, the second microdisplay is a microdisplay with low power consumption compared to the first microdisplay. By “low power consumption”, it is meant here that the second microdisplay has a power consumption of between 0.5 mW and 10 mW, while the first microdisplay has a power consumption greater than or equal to 50 mW.

[0056] Preferably, in embodiment M1, the second microdisplay displays a red dot or a luminous symbol. The luminous object being fixed over time, the electrical consumption of the second microdisplay is greatly reduced.

[0057] Preferably, in embodiment M1, the second microdisplay has a refresh rate less than or equal to 2 Hz in order to reduce its power consumption. In addition, the refresh rate of the first microdisplay is high in order to be compatible with a video stream. Also, the first microdisplay has a refresh rate greater than or equal to 20 Hz.

[0058] As a non-limiting example, in embodiment M1, the first video microdisplay MAI is an OLED MDP07 from Microoled. It allows the reflex viewfinder to operate nominally by projecting all available information: reticle, symbology, image, video stream, etc.

[0059] As a non-limiting example, in embodiment M1, the second video microdisplay MA2 is an OLED MDP05 from Microoled.

[0060] According to a variant (denoted VI) of the first embodiment, the first microdisplay MAI only displays the image of the exterior landscape acquired by the camera, while the second microdisplay MA2 displays a targeting reticle.

[0061] [Fig.3C] illustrates a preferred embodiment of embodiment M1, in which the glasses 10 comprise a battery BT powering the camera CI, the first and second video micro-displays MAI, MA2 and a processor UT controlling the operation of the battery according to a first and a second mode.

[0062] In the first mode, the battery powers the first video micro-display and does not power the second video micro-display when a capacity of the battery is greater than a predetermined limit. Alternatively, according to variant VI, the battery powers the two micro-displays MAI, MA2 in the first operating mode.

[0063] In the second mode, the battery powers the second video micro-display and does not power the first video micro-display when a capacity of the battery is lower than the predetermined limit. Thus, the UT processor allows the operation of the battery according to a second “degraded” mode in order to save the autonomy of the scope 10 when battery capacity falls below a limit defined by the user or the manufacturer. In this degraded mode, only a simple reticle can then be used by the user. Alternatively, the reticle is displayed in combination with at least one element displaying information on the sight, for example a low battery indicator and / or elements allowing various adjustments to be made such as electronic sight adjustment, brightness adjustment, etc.

[0064] Preferably, the predetermined limit of the battery corresponds to a battery life in the first operating mode of less than 1 h of use. By way of non - limiting example, this limit is equal to 1000 mAh ± 50%. This limit allows to continue to obtain the display of a red dot with a battery life of several hundreds of hours via the switch to the second operating mode of the battery.

[0065] In a first variant of the embodiment of [Fig.3C], the processor is further configured so that the battery operates in the second mode (powering the second video micro - display and not the first video micro - display) when the processor detects a malfunction of the first display or of the CI camera. By way of example, the malfunction may be a power supply problem. This variant allows to obtain a more robust pair of glasses 10.

[0066] In a second variant of the embodiment of [Fig.3C], which can be combined with the first variant, the processor is further configured so that the battery operates in the second mode or in the first mode according to the user's selection, for example by pressing one of the control members IC remoted on the mechanical structure SM. This variant makes it possible to obtain a more versatile scope by selecting an enriched mode (first mode) or degraded mode (second mode) depending on the mission and the evolution of the latter.

[0067] According to the embodiment illustrated in Figures 3B and 3C, the telescope of the invention is a reflex viewfinder and the optical chain consisting of the camera, the first micro-display and the eyepiece has a unit magnification, the image of the first micro-display being consistent with that of the external landscape. The optical combination device SC then ensures the perfect superposition of the image of the micro-display on the landscape.

[0068] Alternatively, according to another embodiment, the telescope has a magnification greater than one. For this, the telescope 1 comprises for example an afocal optical system optically arranged downstream of the optical combination device SC to form a superimposed image of the first and second micro-displays and the scene observed with a magnification greater than 1.

[0069] As explained previously, the optical combining device SC is an optical element performing a collimation function for the beam coming from the second micro-display and an overlay function by overlaying the image of the first micro-display and the image of the second micro-display on the external landscape.

[0070] In order to facilitate the design and manufacture of the optical combination device SC, the first micro-display emits radiation RI in a first spectral range and the second micro-display emits radiation R2 in a second spectral range, separate from the first spectral range. This also makes it possible to guarantee optimal transmission of the flux coming from the observed scene and the flux coming from the first micro-display.

[0071] In order to further simplify the design of the SC device, advantageously, the first and second spectral ranges have a spectral extent less than or equal to 20 nm, for example by the addition of spectral filters arranged in front of the micro-displays.

[0072] Alternatively, in order to facilitate the design and manufacture of the optical combination device SC, the two micro-displays emit radiation RI, R2 respectively in the same spectral range but having cross-polarization.

[0073] [Fig.4] is a schematic representation of an embodiment of the telescope 10 in which the optical combination device SC is a holographic or diffractive EH element, or a metasurface.

[0074] The optical combination device SC comprises a planar semi-reflecting surface SR or a surface SR comprising a dichroic treatment adapted to reflect the spectral range of the radiation RI, inclined at approximately 45 degrees relative to the sighting or observation axis x. By "approximately 45 degrees" is meant 45 degrees at ±5 degrees. The planar semi-reflecting surface (or the surface with a dichroic treatment) SR is adapted to carry out the superposition of the image of the first microdisplay (the first image) and the image of the second microdisplay (the second image) on the external landscape.

[0075] Typically, the semi-reflecting surface is integrated into a splitter blade comprising two flat and parallel faces. Alternatively, the semi-reflecting surface is integrated into a splitter cube comprising two flat and parallel faces or a prism.

[0076] The holographic or diffractive element or the metasurface EH is arranged on the optical path of the rays R2 coming from the second display. By its structure, the holographic or diffractive element or the metasurface EH is adapted to form the image at infinity of the second micro-display.

[0077] Holographic optical elements are optical components obtained by recording a two-wave interference phenomenon in a photosensitive material, the interference causing optical index variations within the material which are retained when the hologram is subsequently developed. These elements are called thick phase holograms because the photosensitive material must have a certain thickness to allow the recording of a significant number of interference fringes and also because the index variations only cause phase variations on the incident light waves without amplitude variations. These elements can operate by reflection or by transmission. These holographic elements have a number of remarkable properties. It is, in fact, possible to obtain a wide variety of optical functions by varying the shape of the recording waves. These functions are, in part, independent of the shape of the support of the holographic optical element. Thus, a holographic optical element recorded on a flat support can possess optical power and have a function comparable to that of a prism, a lens or a mirror.

[0078] In the embodiment of [Fig.4], in the case where the element EH is a holographic component, the holographic processing is thus adapted to present an optical power in order to be able to perform the function of collimation of the rays R2 coming from the second display.

[0079] Finally, these holographic elements exhibit, by nature, spectral selectivity. For a given incidence, the holographic component reflects light in a given spectral band and is transparent outside this spectral band, the spectral band depending on the recording wavelength and more generally, on the recording conditions (see in particular the article “Coupled Wave Theory for thick Hologram Gratings”, The Bell System Technical Journal, Vol. 48, Nov. 1969, No. 9 for all information on the diffractive operation of this type of hologram).

[0080] Therefore, when the EH element is a holographic component in the embodiment of [Fig. 4], the first micro-display emits radiation in a first spectral range and the second micro-display emits radiation in a second spectral range disjoint from the first spectral range, the first and second spectral ranges having a spectral extent less than or equal to 20 nm. Thus, the EH holographic element has a holographic processing and / or a structure specifically adapted to form an image at infinity of rays having a wavelength included in the second spectral range and adapted to transmit the first spectral range.

[0081] In the embodiment where the EH element is a diffractive component or a meta-surface, this spectral selectivity can also come from an angle of incidence of the rays coming from the first display relative to the EHD element.

[0082] Alternatively according to another embodiment, to carry out the superposition appropriately when the element EH is a diffractive component or a meta-surface, the two micro-displays MAI, MA2 emit radiation RI, R2 in the same spectral range but having a cross-polarization. In this embodiment, one or more polarized screens are arranged on the optical path of the radiation RI so that the element EH forms an image at infinity of the rays having the polarization associated with the micro-display MA2 and to transmit the rays having the polarization associated with the micro-display MAI.

[0083] According to the embodiment illustrated in Figure 4, the holographic or diffractive element or the metasurface EH is arranged so as to be separated from the planar semi-reflecting surface SR. This embodiment makes it possible to facilitate the design and manufacture of the elements EH and SR. Indeed, it is then possible to design an element EH so that it has an optical power for the rays R2 to perform the collimation function, without it also performing a superposition function for the first image and the second image on the external landscape. Preferably, in this embodiment, the holographic or diffractive element or the metasurface EH is arranged so as to be substantially perpendicular to the sighting or observation axis x. This makes it possible to maximize the compactness of the telescope of the invention.Additionally, depending on the structure of the EH element, this potentially maximizes the transmission of RE rays from the external landscape. By "substantially perpendicular" here is meant that the EH element is perpendicular to ± 10° of the line of sight or observation x.

[0084] By way of non-limiting example, in the embodiment where the EH element is a metasurface or a diffractive element, the EH element is machined for example by a diamond tip, by laser ablation, by lithography, by etching, by molding, or even by pressing.

[0085] In the embodiment where the EH element is a diffractive element, the latter may comprise two or more relief levels (also called levels).

[0086] In the embodiment where the EH element is a metasurface, the latter is created by modulating the density of the reliefs which are all substantially the same height relative to a planar substrate.

[0087] As a non-limiting example, in the embodiment where the EH element is a holographic element, the latter may be a thick volume hologram obtained by interference of two coherent light beams producing a variation of the refractive index in a layer of photosensitive material. Alternatively, the EH element is a thin volume hologram in which the index variation is perpendicular to the substrate, or a surface hologram, or a CGH hologram (for computer generated hologram in English) produced by the same method as an EH diffractive element of the invention.

[0088] Alternatively, according to an embodiment different from that illustrated in [Fig.4], the holographic or diffractive element or the EH metasurface is deposited or reported on the flat semi-reflecting surface SR. This embodiment has a better compactness than that of [Fig.4]. However, it has the disadvantage of being more complex to design and manufacture because a single element must perform a collimation function for the R2 rays and a superposition function for the first image and the second image on the exterior landscape. As a non-limiting example, in this embodiment, the element EH allows the collimation of the RI radiation emitted by the micro-display MAI and the collimation of the R2 radiation emitted by the micro-display MA2. The separation of the RI radiation collimation and R2 collimation functions is allowed via two distinct variants: - the two micro-displays MAI, MA2 emit radiation in the same spectral range but with cross-polarization, - the first micro-display emits the radiation RI in a first spectral range and the second micro-display emits the radiation R2 in a second spectral range, separate from the first spectral range.

[0089] [Fig.5] is a schematic representation of an embodiment of the telescope 10 in which the optical combination device SC comprises the planar semi-reflecting surface SR, an additional eyepiece OC' and a pupil-expanding light guide PE.

[0090] The planar semi-reflective surface SR of the embodiment of [Fig.5] is identical to that described in the embodiment of [Fig.4].

[0091] The additional eyepiece OC' is arranged so as to form an image of the second micro-display at infinity.

[0092] The pupil expansion light guide PE is arranged on the optical path of the rays coming from the second display and is adapted to extend a pupil of the additional eyepiece OC' in two directions of space while also participating in the superposition of the first and second images on the external landscape.

[0093] A pupil expansion light guide PE is a component known per se, made of a transparent material and comprising flat and parallel faces. The light beams coming from the second micro-display MA2 and collimated by the additional eyepiece OC' enter, for example, the light guide through one of its lateral faces. Entry into the guide can be achieved using a prism, but also with a grating, which is then called an input grating. These beams propagate in the light guide by total reflections on flat and parallel faces. For the observer to be able to perceive an image, it is necessary to make it exit the guide. Several optical solutions exist. As a first example, the light guide PE comprises two parallel semi-reflecting plates arranged at an angle between the parallel faces of the light guide PE, so as to extract a portion of the collimated beams.As a second example, the PE light guide. comprises a network of micro-structures or micro-prisms or a diffraction grating that performs the same functions. These elements can be located on one of the two faces of the light guide. They can also be located inside the guide.

[0094] In the embodiment illustrated in [Fig.5], the observer Y looks at the landscape directly through the PE light guide. This is called a “see-through” PE light guide.

[0095] The integration of the pupil expansion light guide PE makes it possible to significantly reduce the size along the x axis of the combining element of the telescope. Indeed, compared to a splitter blade inclined at 45° on the x axis, the PE light guide extends mainly along a plane substantially perpendicular to the x axis. Thus, its length (dimension along the x axis) is reduced to a minimum. The user can thus have a better understanding of his environment.

[0096] Even more preferably, according to an embodiment different from that illustrated in [Fig. 5], the planar semi-reflecting surface SR is replaced by an additional pupil-expanding light guide adapted to extend a pupil of the first eyepiece in two directions of space by superimposing the first and second images on the external landscape. This embodiment has a further improved compactness compared to the embodiment of [Fig. 5].

[0097] [Fig.6] is a schematic representation of an embodiment of the glasses 10 in which the optical combination device SC comprises the planar semi-reflecting surface SR (or the surface SR comprising a dichroic treatment) and an SFF plate comprising two concave surfaces of the “freeform” or aspherical type. A “freeform” or free-form surface is understood to mean a surface which has no symmetry of revolution. It is the shape of these surfaces which directly creates the optical power making it possible to return the image of the second micro-display to infinity towards the user's eye. It is necessary to use an SFF plate with two “freeform” or aspherical surfaces so as not to disturb the vision of the outside landscape through this SFF plate.

[0098] The planar semi-reflective surface SR (or the surface SR comprising a dichroic treatment) of the embodiment of [Fig. 6] is identical to that described in the embodiment of Figures 4 and 5.

[0099] The concave surface SFF of the “freeform” or aspherical type is inclined on the axis of sight or observation v and is arranged on the optical path of the rays coming from the second display so as to form the image at infinity of the second microdisplay MA2. Compared to the embodiments previously mentioned, the concave surface SFF has more degrees of freedom for the optimization of the profile of the surface thus allowing better collimation to be achieved.

[0100] In all its embodiments, the sighting scope according to the invention may comprise complementary modular optical systems making it possible to modify the perception of the exterior 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, upstream of the optical combination device SC an optical module with a light intensifier invariant in magnification and axis deviation may be arranged. The user thus perceives both an intensified image and a thermal image of the exterior landscape.

Claims

Claims

1. Sighting or observation scope (10) having a sighting or observation axis x and comprising, in a mechanical structure (SM): - a camera (CI), - a first video micro-display (MAI) displaying an image of the exterior landscape acquired by the camera, called the first object - an eyepiece (OC) associated with the first video micro-display and forming a first image of the first object at infinity - a second video micro-display (MA2) displaying a second object - an optical combining device (SC) optically arranged downstream of the eyepiece and is adapted to form an image at infinity of the second object, called the second image, and to superimpose the first and second images on the exterior landscape.

2. The eyewear of claim 1, wherein the second microdisplay is a low power consumption microdisplay compared to the first microdisplay.

3. A bezel according to claim 2, wherein the second microdisplay has a refresh rate less than or equal to 2 Hz, the first microdisplay having a refresh rate greater than or equal to 20 Hz.

4. Glasses according to claim 2 or 3, comprising a battery powering the camera, the first and second video micro-displays and a processor, said processor being configured to operate the battery in two distinct modes consisting of: - in a first mode, powering the first video micro-display and not powering the second video micro-display or powering the first and second micro-displays (MAI, MA2) when a battery capacity is greater than a predetermined limit or when the user so chooses, for example by pressing a control member (IC) remote on said mechanical structure, - in a second mode, powering the second video micro-display and not powering the first video micro-display when a battery capacity is lower than the predetermined limit, or when the processor detects a malfunction of the first display, or when the user chooses it, for example by pressing a control member (IC) located on said mechanical structure.

5. Glasses according to the preceding claim, in which the predetermined limit corresponds to a battery life in the first operating mode of less than 1 hour of use.

6. Glasses according to any one of the preceding claims, in which the first micro-display emits radiation in a first spectral range and the second micro-display emits radiation in a second spectral range, separate from the first spectral range or the first and second micro-displays (MAI, MA2) emit radiation in the same spectral range but having cross-polarization.

7. A telescope according to any one of the preceding claims, in which the optical combination device comprises: - a planar semi-reflecting surface (SR) inclined at approximately 45 degrees relative to the viewing or observation axis x or a surface (SR) comprising a dichroic treatment adapted to reflect a spectral range of the radiation emitted by the first micro-display, said planar semi-reflecting surface (SR) being adapted to carry out said superposition of the first and second images on the external landscape - a holographic or diffractive element or a metasurface (EH) arranged on the optical path of the rays coming from the second display and adapted to form said second image.

8. A spectacle according to the preceding claim in combination with claim 6, wherein said holographic or diffractive element or said metasurface (EH) has a holographic treatment and / or a structure specifically adapted to form an image of rays having a wavelength included in the second spectral range and adapted to transmit the first spectral range.

9. Glasses according to claim 7 or 8, in which said holographic or diffractive element or said metasurface (EH) is deposited or attached to the planar semi-reflecting surface (SR).

10. A spectacle according to claim 7 or 8, wherein said holographic or diffractive element or said metasurface (EHD) is separated from the planar semi-reflective surface (SR).

11. A telescope according to the preceding claim, wherein said holographic or diffractive element or said metasurface (EH) is arranged so as to be substantially perpendicular to the axis of sight or observation x.

12. A telescope according to claim 10, wherein said holographic or diffractive element or said metasurface (EH) comprises a concave surface inclined on the axis of sight or observation x.

13. Glasses according to any one of claims 1 to 6 and 8 to 12, in which the optical combination device comprises: - a planar semi-reflecting surface (SR) inclined at approximately 45 degrees relative to the sighting or observation axis x, said planar semi-reflecting surface (SR) being adapted to carry out said superposition of the first and second images on the external landscape - a concave surface (SFF) of the "freeform" or aspherical type inclined on the sighting or observation axis x and arranged on the optical path of the rays coming from the second display so as to form said second image.

14. A spectacle according to any one of claims 1 to 6 and 8 to 12, wherein the optical combination device comprises: - a planar semi-reflecting surface (SR) inclined at approximately 45 degrees relative to the sighting or observation axis x, said planar semi-reflecting surface (SR) being adapted to carry out said superposition of the first and second images on the external landscape - an additional eyepiece (OC') adapted to form the second image, - a pupil expansion light guide (PE) arranged on the optical path of the rays coming from the second display and adapted to expand a pupil of the additional eyepiece (OC') into two directions of space, also participating in the said superposition of the first and second images on the exterior landscape.

Images