Patent Application
20240036302
This invention concerns night-vision binoculars.
More precisely, the invention concerns night-vision binoculars configured to capture and intensify images originating from a scene. The spectral domain of intensification is typically between 450 and 950 nm. When such binoculars are configured to project information originating from a screen on the intensified image, they are referred to as ‘connected’.
Connected night-vision binoculars comprising two capture paths, each associated with an eyepiece, are known from the prior art. However, only one of the two paths is associated with means of projection of information from a screen on the image captured. Thus, the information originating from the screen is only visible through one of the eyepieces, which is problematic when this eyepiece does not correspond to the dominant eye of the user.
This projection on only one of the two paths is explained by the technical and economic difficulties of providing a mechanism for adjusting the inter-pupillary distance (IPD) between the two eyepieces. In particular, in the night-vision binoculars available on the market, the IPD adjustment is either linear or rotary.
In the case of linear IPD adjustment, the two binocular bodies are guided mechanically by a slide link on a bracket. The bracket connects the two binocular bodies to the mechanical mount of the helmet or head harness. For unconnected night-vision binoculars (no screen), the power supply of the intensifier tube goes through flexible webs connecting the binocular bodies to the bracket or through electrical contacts on a track.
In the case of connected night-vision binoculars, the cables providing the power supply for the screen and the connection to video signals are added to those providing power to the intensifier tube, which makes the incorporation of such cables into the binocular body both technically and economically complex. The night-vision binoculars available on the market thus do not have an adjustable IPD and have a screen on a single path.
In the case of rotary IPD adjustment, the two binocular bodies are guided mechanically by a pivoting link on a bracket connecting the two binocular bodies to the mechanical support frame of the helmet or head harness. This type of IPD adjustment makes the passage of the cables easier than in the case of linear IPD adjustment solutions.
However, in the case of connected night-vision binoculars, this type of IPD adjustment induces rotation of the images from the screen. The images from the screen are thus perceived at an incline by the user. Solutions that incorporate a mechanical derotator are conceivable, but unsuitable from the microeconomic standpoint. Thus, for this reason, too, the night-vision binoculars available on the market do not have an adjustable IPD and have a screen on a single path.
There is thus a need for connected night-vision binoculars allowing for an intensified image of the scene comprising information from a screen to be visualized via both eyepieces, whilst also having an adjustable IPD.
To this end, this description concerns night-vision binoculars comprising:
In particular embodiments, the binoculars comprise one or more of the following characteristics, alone or in any combination technically possible:
Other characteristics and advantages of the invention will become apparent from a reading of the following description of embodiments of the invention, which are provided solely by way of example, and by reference to the drawings:
Examples of night-vision binoculars 10 are shown schematically in
This description first describes the elements common to the three embodiments. Each embodiment is thereafter described more specifically.
The binoculars 10 are, e.g., intended to be mounted on a helmet or head harness. Advantageously, the binoculars 10 are also intended to be affixed to a vertically (up-down) adjusted support, thus allowing the height of the binoculars 10 to be adjusted.
As shown in
When the binoculars 10 comprise two distinct lens assemblies 12, as in
The association of one eyepiece 14A, 14B with the corresponding lens assembly 12 forms an optical path, with the binoculars 10 thus comprising two optical paths.
Each lens assembly 12 is fixed, i.e. it cannot be translated or rotated.
Each lens assembly 12 comprises at least the following elements: a capture lens 20, a light intensification device 22, a screen 24, and a projection lens 26.
The capture lens 20 is configured to capture an image of a scene. For example, the capture lens 20 comprises an assembly of several lenses.
The light intensification device 22 is configured to intensify the image captured in order to obtain an intensified image. For example, the light intensification device 22 comprises one or more intensifier tubes.
The screen 24 is suited to generate an additional image. The additional image is intended to provide additional information to the user of the binoculars 10.
For example, the additional image is an image of the scene in a spectral band different to the spectral band of the image captured by the capture lens 20. For example, the different spectral band is within an infrared (near, far, or middle infrared) band, whilst the capture lens 20 is, e.g., suited to capture images in the visible band (380-780 nm) or extended (400-900 nm) band. The additional image is, e.g., obtained by an additional optical path present in the binoculars 10.
In one variant, the additional image originates from data obtained by sensors or other sources of information.
The projection lens 26 is configured to project the additional image on the intensified image such that the output beam of the projection lens 26 (‘projection beam FP’) transports the resultant image (superimposition of the intensified image and the additional image). It should be noted that only one ray of the beam FP is shown in the relevant figures for the sake of simplicity.
Advantageously, in the intermediate space between the projection lens 26 and the corresponding eyepiece 14A, 14B, the projection beam FP is a collimated or near collimated beam. ‘Collimated’ means that the rays of the projection beam FP are parallel or nearly parallel in the intermediate space. ‘Near collimated’ means that the rays of the projection beam FP are nearly parallel locally, i.e. over a distance of less than or equal to a value that allows the optical axis of each eyepiece 14A, 14B to be made insensitive to eccentricities of the mechanical axis between the eyepieces 14A, 14B and the one or more corresponding lens assemblies 12.
The projection lens 26 has an output axis (‘projection axis AP’), which is also the output axis of the lens assembly 12.
For example, the projection lens 26 comprises an assembly of several lenses.
Each eyepiece 14A, 14B is an image-transporting lens, i.e. it is suited to transport the image resulting from the projection to the user's eye.
When the binoculars 10 comprise two distinct lens assemblies 12, as shown in
Each eyepiece 14A, 14B has an output axis (vision axis AV′) (see, inter alia,
The vision axis Av of each eyepiece 14A, 14B is parallel to the projection axis AP of the corresponding lens assembly 12 and is a non-zero centre-to-centre distance E from the projection axis A P of the corresponding lens assembly 12. The centre-to-centre distance is the same for both eyepieces 14A, 14B.
Each eyepiece 14A, 14B is rotatable relative to the projection axis AP of the corresponding lens assembly 12 so as to change the adjustment range R and thus adjust the inter-pupillary distance IPD.
The aspects of the operation of the binoculars 10 that are common to the three embodiments will now be described.
To adjust the IPD between the eyepieces 14A, 14B of the binoculars 10, the user turns each of the eyepieces 14A, 14B about the projection axis AP of the corresponding lens assembly 12. In particular, for an average adjustment configuration in which the adjustment range R is nil, the user turns each of the eyepieces 14A, 14B outward in order to increase the IPD and inward in order to decrease the IPD.
Once the IPD has been adjusted, the image resulting from the projection of the additional image over the intensified image of the scene is visible to the user through each of the eyepieces 14A, 14B.
Thus, such connected night-vision binoculars 10 allow the image resulting from the projection of the additional image over the intensified image of the scene to be visualised via both eyepieces 14A, 14B. This makes it easier to visualise such an image than with the known-art devices, in which the resultant image can only be seen on one optical path.
In particular, compared to known-art binoculars that comprise linear IPD adjustment, the adjustment of the IPD via a rotation mechanism makes it easier to incorporate the power cables of the light intensification device 22 and the screen 24 into the binoculars 10. Thus, the cables do not pass through the eyepieces 14, 14B and are independent of the IPD adjustment mechanism.
Moreover, unlike known-art binoculars that comprise rotary IPD adjustment, the IPD adjustment does not affect the resultant image of the scene. This is due to the fact that only the eyepieces 14A, 14B are mobile, whilst the one or more lens assemblies 12 comprising the screen 24 are fixed.
Thus, the connected night-vision binoculars 10 allow the resultant image to be visualised on each of the eyepieces 14A, 14B, whilst maintaining the adjustability of the IPD, by means of a dissymmetry between the projection axis AP of the/each lens assembly 12 and the vision axis Av of the corresponding eyepieces 14A, 14B.
Such an architecture can be adapted both for binocular and binocular binoculars. In particular, it allows for night-vision binoculars with optical fusion (intensified path and infrared path) with a single infrared capture path that is redistributed over the two projection paths (right, left) and compatible with IPD adjustment on both paths.
Moreover, when the beam in the intermediate space is collimated or near collimated, the maintenance of parallelism between the right and left paths is facilitated after the IPD has been adjusted.
Below, the specific aspects of the binoculars 10 according to the first embodiment are described by reference to
As noted above, the binoculars 10 according to the first embodiment comprise two lens assemblies 12. Such lens assemblies 12 are advantageously identical. The optical axis of each lens assembly 12 advantageously coincides with the projection axis AP of the projection lens 26 of the lens assembly 12.
In the first embodiment, the vision axis Av of each eyepiece 14A, 14B coincides with the optical axis of the eyepiece 14A, 14B. Thus, the input axis of each eyepiece 14A, 14B coincides with the vision axis AV of that eyepiece 14A, 14B.
In the first embodiment, the adjustment range R has a value within a limited range [−X; +X] centred on zero. The maximum limit +X of the range is thus equal to the opposite of the minimum limit −X of the range. As shown in
The medium configuration (medium adjustment) corresponds to an average distance for which the IPD is equal to the nominal distance N, where the adjustment range R is nil. In this configuration, the relative eccentricity of the eyepieces 14A, 14B is orientated vertically, and does not contribute to the IPD adjustment. In the configuration shown, the eccentricity is orientated downward. However, upward eccentricity is also possible. When the binoculars 10 are affixed to a vertically (up-down) adjusted support, the vertical eccentricity of the binoculars 10 can be compensated for by translation.
The configuration on the left corresponds to a minimal IPD, for which the adjustment range R is equal to the lower limit −X of the limited range [−X; +X]. In this case, the IPD is equal to N−X. Relative to the medium adjustment (medium configuration), the eccentricity of each eyepiece 14A, 14B relative to the corresponding lens assembly 12 is orientated inward.
The configuration on the right corresponds to a maximum IPD, for which the adjustment range R is equal to the upper limit +X of the limited range [−X; +X]. In this case, the IPD is equal to N+X. Relative to the medium adjustment (medium configuration), the eccentricity of each eyepiece 14A, 14B relative to the corresponding lens assembly 12 is orientated outward.
Thus, the binoculars 10 according to the first embodiment have a dissymmetry obtained by eccentricity between the projection lenses and the corresponding eyepieces 14A, 14B, which allows for the IPD adjustment and the other advantages described in relation to the generic embodiment.
Below, the specific aspects of the binoculars 10 according to the second embodiment are described by reference to
As noted above, the binoculars 10 according to the second embodiment comprise two lens assemblies 12 (one for each eyepiece 14A, 14B). Such lens assemblies 12 are advantageously identical.
In the specific example shown in
In particular, in this example, the input axis of each lens assembly 12 is offset from the projection axis AP of the corresponding projection lens 26 by a layover formed by two dioptres L1, L2. In this example, each dioptre L1, L2 has a flat optical surface that is parallel to the flat optical surface of the other dioptre. Such a layover is also referred to as a rhombohedral layover. The first dioptre L1 is comprised in the capture lens 20 and is suited to reflect the captured and intensified image of the scene in the direction of the second dioptre L2. The second dioptre L2 is comprised in the projection lens 26, and is on the path of the beam reflected by the first dioptre L1.
In this example, the flat optical surface of the second dioptre L2 is partially reflective, so as to reflect the beam originating from the first dioptre L1 on the one hand, and, on the other, transmit the beam originating from the screen 24, such that the two beams are superimposed in the direction of the projection axis AP exiting the second dioptre L2. For example, the first dioptre L1 is a reflective mirror.
Persons skilled in the art will understand that the second embodiment is not limited to such a configuration of the lens assemblies 12, and is functional no matter the configuration of the lens assemblies 12. Thus, in one variant, the input axis of each lens assembly 12 coincides with the projection axis AP of the projection lens 26 of the lens assembly 12, as is the case in the first embodiment.
In the second embodiment, as shown in
In particular, the first dioptre L1′ is positioned so as to be in the path of the projection beam FP as it exits the corresponding projection lens 26 and to reflect the projection beam FP in the direction of the second dioptre L2′. The second dioptre L2′ is positioned so as to reflect the projection beam FP in the direction of the vision axis Av. In one example, the first dioptre L1′ and the second dioptre L2′ are reflective mirrors.
In this second embodiment, the adjustment range R is a function of: The centre-to-centre distance E between the projection axis AP and the vision axis AV of the corresponding eyepiece 14A, 14B, a nominal orientation β of the eyepieces 14A, 14B, and a rotation angle αp, αn of each eyepiece 14A, 14B relative to the nominal orientation β. The nominal orientation β is defined as the angle between the plane comprising the two projection axes AP (right and left) and the symmetry axis of the rhombohedron.
More precisely, for example, the nominal distance N is given by the following formula:
N=D+2·E·tan(β)
Where:
The adjustment range R is, e.g., given by the following formula:
Where:
Thus, the IPD is adjusted by rotating each of the eyepieces 14A, 14B about the corresponding projection axis AP.
In particular, in the medium adjustment position, the relative rotation of the plane of symmetry of the rhombohedra of the eyepieces 14A, 14B relative to the lens assemblies 12 is orientated on the nominal orientation β (αp and αn are nil). At maximum distance, this rotation is orientated outward by the angle β−αp. At minimum distance, this rotation is orientated inward by the angle β+αn.
Thus, the binoculars 10 according to the second embodiment have a dissymmetry obtained by a rhombohedral layover of the eyepieces 14A, 14B, which allows for the IPD adjustment and the other advantages described in relation to the generic embodiment.
The range of rotation of the eyepieces 14A, 14B for the IPD adjustment is reduced compared to the first embodiment. Moreover, aberrations are reduced because the overall optical system has rotational symmetry.
Moreover, in the second embodiment, the length of the binocular bodies 10 is reduced compared to conventional binocular inline optics. As such, the cantilever of the binoculars 10 mounted on a helmet or head harness is reduced.
Below, the specific aspects of the binoculars 10 according to the third embodiment are described by reference to
As noted above, the binoculars 10 according to the third embodiment comprise a single lens assembly 12 shared by both eyepieces 14A, 14B. In particular, the projection axis AP is the shared rotation axis of the two eyepieces 14A, 14B. For example, the lens assembly 12 is a lens assembly according to any of the examples described for the first or third embodiment.
In the third embodiment, as shown in
In particular, the flat optical surface of the first dioptre L1-A of the first eyepiece 14A is partially reflective. The first dioptre L1-A of the first eyepiece 14A is positioned so as to be in the path of the projection beam FP exiting the projection lens 26 so as to reflect part of the projection beam FP in the direction of the second dioptre L2-A of the first eyepiece 14A and to transmit the other part in the direction of the first dioptre L1-B of the second eyepiece 14B.
The second dioptre L2-A of the first eyepiece 14A is positioned so as to reflect the projection beam FP originating from the first dioptre L1-A in the direction of the vision axis AV of the first eyepiece 14A. For example, the second dioptre L2-A is a reflective mirror.
The first dioptre L1-B of the second eyepiece 14B is positioned so as to receive and reflect the part of the beam transmitted by the first dioptre L1-A of the first eyepiece 14A in the direction of the second dioptre L2-B of the second eyepiece 14B. For example, the first dioptre L1-A is a reflective mirror.
Le second dioptre L2-B of the second eyepiece 14B is positioned so as to reflect the projection beam FP originating from the first dioptre L1-B of the second eyepiece 14B in the direction of the vision axis AV of the second eyepiece 14B. For example, the first dioptre L1-B is a reflective mirror.
Advantageously, the centre-to-centre distance E between the projection axis AP and the vision axis AV of each eyepiece 14A, 14B (which also corresponds to the distance between the reflective surfaces de each rhombohedron) meets the following condition:
E+D1=D2+E+D3
Where:
In this third embodiment, the adjustment range R is a function of: The centre-to-centre distance E between the projection axis AP and the vision axis AV of the corresponding eyepiece 14A, 14B, a nominal orientation β of the eyepieces 14A, 14B, and a rotation angle αp, an of each eyepiece 14A, 14B relative to the nominal orientation β.
More precisely, for example, the nominal distance N is given by the following formula:
N=2·E·tan(β)
The adjustment range R is, e.g., given by the following formula:
Where:
Thus, the IPD is adjusted by rotating each of the eyepieces 14A, 14B about the corresponding projection axis AP.
In particular, in the medium adjustment position, the relative rotation of the plane of symmetry of the rhombohedra of the eyepieces 14A, 14B relative to the lens assemblies 12 is orientated on the nominal orientation β (αp and an are nil). At maximum distance, this rotation is orientated outward by the angle β−αp. At minimum distance, this rotation is orientated inward by the angle β+αn.
Thus, the binoculars 10 according to the third embodiment allow for a binocular vision device having dissymmetry with each eyepiece 14A, 14B, produced by a rhombohedral layover of the eyepieces 14A, 14B. This allows for IPD adjustment and the other advantages described in relation to the generic embodiment.
The range of rotation of the eyepieces 14A, 14B for the IPD adjustment is reduced compared to the first embodiment. Moreover, aberrations are reduced because the overall optical system has rotational symmetry.
Moreover, in the third embodiment, the length of the binocular bodies 10 is reduced compared to conventional biocular inline optics. As such, the cantilever of the binoculars 10 mounted on a helmet or head harness is reduced.
Persons skilled in the art will understand that the embodiments described above can be combined where compatible. In particular, the rhombohedral lens assembly 12 described in relation to the second embodiment is compatible with the first and third embodiment. Likewise, the inline lens assembly 12 described in relation to the first embodiment is compatible with the second and third embodiment.
Moreover, persons skilled in the art will understand that, for an optical system, the term ‘output axis’ corresponds to the optical axis of the optic at the output of the optical system, and that the term ‘input axis’ corresponds to the optical axis of the optic at the input of the optical system. Thus, where the optical system is centred, the output axis and the input axis both correspond to the optical axis of the optical system. In particular, in the embodiments described, the projection axis AP (output axis of the lens assembly) is parallel to the input axis of the lens assembly (optical axis of the capture lens 20).
Lastly, persons skilled in the art will understand that, in the second and third embodiment (
| Number | Date | Country | Kind |
|---|---|---|---|
| FR2013655 | Dec 2020 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/086607 | 12/17/2021 | WO |
