NIGHT VISION BINOCULARS
Night vision binoculars with adjustable eyepieces and fixed objective blocks allow simultaneous image viewing through both lenses with aligned images, addressing IPD adjustment and cable integration issues.
Patent Information
- Application Number
- FR2020013655
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2020-12-18
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2040-12-18
AI Technical Summary
Existing night vision binoculars with screen projection capabilities are not adjustable in interpupillary distance (IPD) and often require complex cable integration, leading to uneven image perception and mechanical limitations.
The binoculars feature adjustable eyepieces that rotate relative to a fixed objective block, allowing parallel vision axes and independent power supply cables, enabling IPD adjustment without affecting image alignment.
Enables simultaneous image viewing through both eyepieces with adjusted IPD, simplifying cable integration and maintaining image alignment, thus improving user experience and reducing mechanical complexity.
Smart Images
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Abstract
Description
Title of invention: Night vision binoculars
[0001] The present invention relates to night vision binoculars.
[0002] More specifically, the invention relates to night vision binoculars configured to capture and intensify images from a scene. The intensification spectral range is typically between 450 nanometers (nm) and 950 nm. When such binoculars are configured to project information from a screen onto the intensified image, they are said to be connected.
[0003] Connected binocular night vision goggles are known comprising two capture channels, each associated with an eyepiece. However, only one of the two channels is associated with means for projecting, onto the captured image, information from a screen. Thus, the information from the screen is visible only via one of the eyepieces, which is problematic when this eyepiece does not correspond to the user's dominant eye.
[0004] The projection on only one of the two paths is explained by the technical and economic difficulties of producing the inter-pupillary adjustment (IPD) mechanism between the two eyepieces. In particular, on night vision binoculars available on the market, the IPD adjustment is carried out either by translation or by rotation.
[0005] In the case of a translational IPD adjustment, the two binocular bodies are mechanically guided by a sliding connection on a bracket. The bracket connects the two binocular bodies to the mechanical mount of the helmet support or head harness. For non-connected night vision binoculars (without a screen), the power supply to the intensifier tube passes through flexible cables connecting the binocular bodies to the bracket or through electrical contactors on the track.
[0006] In the case of connected night vision binoculars, the power supply cables for the screen and for connecting to the video signals are added to those for supplying the intensifier tube, which makes the integration of such cables into the binocular bodies complex to achieve both technically and economically. The night vision binoculars available on the market are, therefore, not adjustable in IPD and have a screen on a single channel.
[0007] In the case of a rotational IPD adjustment, the two binocular bodies are mechanically guided by a pivot connection on a bracket connecting the two binocular bodies to the mechanical mount of the helmet support or head harness. This type of IPD adjustment makes it easier to pass through connections compared to translational IPD adjustment solutions.
[0008] However, in the case of connected night vision binoculars, this type of IPD adjustment induces a rotation of the images from the screen. The images from the screen are therefore perceived inclined by the user. Solutions introducing a mechanical de-rotator are possible, but unsuitable from a micro-economic point of view. Thus, here again the connected night vision binoculars available on the market are not adjustable in IPD, and have a screen on only one channel.
[0009] There is therefore a need for connected night vision binoculars allowing viewing via the two eyepieces of an intensified image of the scene integrating information from a screen, while being adjustable in IPD.
[0010] For this purpose, the present description relates to night vision binoculars comprising: a. at least one fixed objective block, the or each objective block comprising: i. a capture lens configured to capture an image of a scene, ii. a light intensifying device configured to intensify the captured image to obtain an intensified image, iii. a screen capable of generating an additional image, iv. a projection lens configured to project the additional image onto the intensified image so that the output beam of the projection lens, called the projection beam, carries the resulting image, the projection lens having an output axis, called the projection axis, b. two image-carrying eyepieces receiving either the same projection beam when the binoculars comprise a single objective unit, or separate projection beams when the binoculars comprise two objective units,
[0011] each eyepiece having an exit axis, called the vision axis, the vision axes of the two eyepieces being parallel and separated by an adjustable distance, called the interpupillary distance,
[0012] the axis of vision of each eyepiece being, in addition, parallel to the projection axis of the corresponding objective block and having the same non-zero center distance with the projection axis of the corresponding objective block,
[0013] each eyepiece being rotatable relative to the projection axis of the corresponding objective block so as to adjust the inter-pupillary spacing.
[0014] According to particular embodiments, the binoculars comprise one or more of the following characteristics, taken in isolation or in all technically possible combinations:
[0015] - the projection beam is a collimated or near-collimated beam;
[0016] - the axis of vision of each eyepiece is the optical axis of the eyepiece;
[0017] - the binoculars comprise two objective blocks, the inter-pupillary distance being the sum of a nominal spacing and an adjustment amplitude, the value of the adjustment amplitude being a function of the rotation of each eyepiece, and being included in a bounded interval centered on zero, the center distance between the vision axis of each eyepiece and the projection axis of the corresponding objective block being equal to half the positive terminal of the bounded interval;
[0018] - each eyepiece has an input axis coinciding with the projection axis of the block corresponding objective, the axis of vision of each eyepiece being offset from the input axis of said eyepiece by a folding formed of two diopters, each diopter having a flat optical surface parallel to the flat optical surface of the other diopter, the first diopter being configured to reflect in the direction of the second diopter at least part of the projection beam at the output of the corresponding objective block, the second diopter being configured to reflect said projection beam in the direction of the axis of vision;
[0019] - the inter-pupillary distance is the sum of a nominal distance and a adjustment amplitude depending on the rotation of each eyepiece, the adjustment amplitude being a function of the center distance between the projection axis and the vision axis of the eyepieces, of a nominal orientation of the eyepieces, and of an angle of rotation of each eyepiece relative to the nominal orientation;
[0020] - the binoculars include two objective blocks;
[0021] - the binoculars comprise a single objective block so that the projection axis is the common axis of rotation of the two eyepieces, the flat optical surface of the first diopter of one of the eyepieces, called the first eyepiece, being partially reflective so as to reflect part of the projection beam in the direction of the second diopter of said first eyepiece and to transmit the other part in the direction of the other eyepiece, called the second eyepiece;
[0022] - the or each objective block comprises an input axis offset from the projection axis of the corresponding projection objective by a folding formed of two diopters, each diopter having a flat optical surface parallel to the flat optical surface of the other diopter, the first diopter being included in the capture objective, the second diopter being included in the projection objective and being on the path of the beam reflected by the first diopter;
[0023] - the additional image is an image of the scene in a different spectral band of the spectral band of the image captured by the capture lens.
[0024] Other characteristics and advantages of the invention will appear on reading the following description of embodiments of the invention, given by way of example only and with reference to the drawings which are:
[0025] [Fig. 1], [Fig. 1], a schematic representation of an example of night vision binoculars according to a first and a second embodiment,
[0026] [Fig.2], [Fig.2], a schematic representation of an example of vision binoculars nocturnal according to a third embodiment,
[0027] [Fig.3], [Fig.3], a schematic representation of an example of a path of the night vision binoculars according to the first embodiment,
[0028] [Fig.4], [Fig.4], a schematic representation of different examples of inter-pupillary adjustment according to the first embodiment, with visualization of the offsets between the entrance pupil of the objective blocks and the exit pupil of the eyepieces,
[0029] [Fig.5], [Fig.5], a schematic representation of an example of a path of the night vision binoculars according to the second embodiment,
[0030] [Fig.6], [Fig.6], a schematic representation of an example of interpupillary adjustment according to the second embodiment,
[0031] [Fig.7], [Fig.7], a schematic representation of an example of the two paths of the night vision binoculars according to the third embodiment, and
[0032] [Fig.8], [Fig.8], a schematic representation of an example of interpupillary adjustment according to the third embodiment.
[0033] Examples of night vision binoculars 10 are shown schematically in Figures 1 and 2. [Fig. 1] corresponds to a first and a second embodiment of the invention. [Fig. 2] corresponds to a third embodiment of the invention. As described below, the binoculars 10 are so-called connected binoculars because they integrate a screen and a projection lens.
[0034] In the present description, the elements common to the three embodiments are first described. Each embodiment is then described more specifically thereafter. Generic embodiment
[0035] The binoculars 10 are, for example, intended to be mounted on a helmet or a head harness. Advantageously, the binoculars 10 are also intended to be fixed to a support that can be adjusted vertically (up-down), which makes it possible to adjust the height of the binoculars 10.
[0036] As illustrated in Figures 1 and 2, the binoculars 10 comprise at least one objective block 12 and two eyepieces 14A, 14B.
[0037] When the binoculars 10 comprise two separate objective blocks 12 as is the case in [Fig. 1], each eyepiece 14A, 14B is associated with a respective objective block 12 and therefore does not receive a light beam from the other objective block 12. When the binoculars 10 comprise a single objective block 12 as is the case in [Fig. 2], the objective block 12 is common to both eyepieces 14A, 14B.
[0038] The association of an eyepiece 14A, 14B with the corresponding objective block 12 forms an optical path, the binoculars 10 thus comprising two optical paths.
[0039] Each objective block 12 is fixed, that is to say that it cannot be moved either in translation or in rotation.
[0040] Each objective block 12 comprises at least the following elements: a capture objective 20, a light intensification device 22, a screen 24 and a projection objective 26.
[0041] The capture lens 20 is configured to capture an image of a scene. The capture lens 20 comprises, for example, an assembly of several lenses.
[0042] The light intensifying device 22 is configured to intensify the captured image to obtain an intensified image. The light intensifying device 22 comprises, for example, one or more intensifier tubes.
[0043] The screen 24 is capable of generating an additional image. The additional image is intended to provide additional information to the user of the binoculars 10.
[0044] The additional image is, for example, an image of the scene in a spectral band different from the spectral band of the image captured by the capture objective 20. The different spectral band is, for example, included in an infrared band (near, medium or far infrared), whereas the capture objective 20 is, for example, capable of capturing images in the visible band (380 nm to 780 nm) or extended band (400 nm to 900 nm). The additional image is, for example, obtained by an additional optical channel present in the binoculars 10.
[0045] Alternatively, the additional image comes from data obtained by sensors or other sources of information.
[0046] The projection lens 26 is configured to project the additional image onto the intensified image so that the output beam of the projection lens 26, called the projection beam FP, carries the resulting image (superposition of the intensified image and the additional image). It should be noted that only one ray of the beam FP is shown in the figures concerned so as not to overload them.
[0047] Advantageously, in the intermediate space between the projection objective 26 and the corresponding eyepiece 14A, 14B, the projection beam FP is a collimated or near-collimated beam. By the term "collimated", it is understood that the rays of the projection beam FP are parallel or almost parallel in the intermediate space. By the term "near-collimated", it is understood that the rays of the projection beam FP are almost parallel locally, that is to say over a distance less than or equal to a value making it possible to make the optical axis of each eyepiece 14A, 14B insensitive to mechanical axis eccentricities between the eyepieces 14A, 14B and the corresponding objective block(s) 12.
[0048] The projection objective 26 has an exit axis, called the projection axis AP, which is also the exit axis of the objective block 12.
[0049] The projection lens 26 comprises, for example, an assembly of several lenses.
[0050] Each eyepiece 14A, 14B is an image transport eyepiece, that is to say that it is suitable for transporting the image resulting from the projection to the user's eye.
[0051] When the binoculars 10 comprise two separate objective blocks 12, as illustrated in [Fig. 1], the two eyepieces 14A, 14B receive separate projection beams FP and then carry separate resulting images. When the binoculars 10 comprise a single objective block 12, as illustrated in [Fig. 2], the two eyepieces 14A, 14B receive the same projection beam FP and then carry the same resulting image.
[0052] Each eyepiece 14A, 14B has an output axis, called the vision axis Av (see in particular FIGS. 3 to 8 which will be detailed in the remainder of the description). The vision axes of the two eyepieces 14A, 14B are parallel and separated by an adjustable distance, called the interpupillary distance IPD. The interpupillary distance IPD is typically the sum of a nominal distance N (fixed) and an adjustment amplitude R (variable).
[0053] The axis of vision Av of each eyepiece 14A, 14B is parallel to the projection axis AP of the corresponding objective block 12 and has a non-zero center distance E with the projection axis AP of the corresponding objective block 12. The center distance E is the same for the two eyepieces 14A, 14B.
[0054] Each eyepiece 14A, 14B is rotatable relative to the projection axis AP of the corresponding objective block 12 so as to modify the adjustment amplitude R and thus adjust the inter-pupillary distance IPD.
[0055] An operation of the binoculars 10 common to the three embodiments will now be described.
[0056] To adjust the interpupillary distance IPD between the eyepieces 14A, 14B of the binoculars 10, the user turns each of the two eyepieces 14A, 14B around the projection axis AP of the corresponding objective block 12. In particular, compared to a medium adjustment configuration for which the adjustment amplitude R is zero, the user turns each of the eyepieces 14A, 14B outwards to increase the interpupillary distance IPD, and inwards to decrease the interpupillary distance IPD.
[0057] Once the interpupillary distance IPD has been adjusted, the image resulting from the projection of the additional image onto the intensified image of the scene can be observed by the user via each of the two eyepieces 14A, 14B.
[0058] Thus, such connected night vision binoculars 10 allow viewing, via the two eyepieces 14A, 14B, of the image resulting from the projection of the additional image onto the intensified image of the scene. This facilitates viewing of such an image compared to devices of the prior art for which this resulting image is observable only on an optical path.
[0059] In particular, compared to binoculars of the state of the art incorporating inter-pupillary adjustment by translation, the adjustment of the inter-pupillary distance IPD by a rotation mechanism facilitates the integration of the power cables of the device. light intensification 22 and screen 24 in binoculars 10. The cables thus do not pass through eyepieces 14A, 14BB and are independent of the inter-pupillary adjustment mechanism.
[0060] Furthermore, compared to binoculars of the prior art incorporating inter-pupillary adjustment by rotation, the inter-pupillary adjustment has no impact on the resulting image of the scene. This is explained by the fact that only the eyepieces 14A, 14B are movable, whereas the objective block(s) 12 which incorporate the screen 24 are fixed.
[0061] Thus, the connected night vision binoculars 10 allow, via an asymmetry between the projection axis AP of the or each objective block 12 and the vision axis Av of the corresponding eyepieces 14A, 14B, to view the resulting image on each of the two eyepieces 14A, 14B, while being adjustable in IPD.
[0062] Such an architecture is adaptable for both binocular and biocular binoculars. In particular, it makes it possible to produce night vision binoculars with optical fusion (intensified path and infrared path) with a single infrared capture path redistributed over the two projection paths (right, left) and compatible with inter-pupillary adjustment on both paths.
[0063] Furthermore, when the beam in the intermediate space is collimated or close to collimated, maintaining parallelism is facilitated between the two right and left channels after carrying out the inter-pupillary adjustment. First embodiment
[0064] In the following, the specific features of the binoculars 10 according to the first embodiment are described with reference to FIGS. 1, 3 and 4.
[0065] As indicated previously, the binoculars 10 according to the first embodiment comprise two objective blocks 12. Such objective blocks 12 are advantageously identical. The optical axis of each objective block 12 is advantageously coincident with the projection axis AP of the projection objective 26 of said objective block 12.
[0066] According to the first embodiment, the axis of vision Av of each eyepiece 14A, 14B coincides with the optical axis of said eyepiece 14A, 14B. Thus, the input axis of each eyepiece 14A, 14B and the axis of vision Av of said eyepiece 14A, 14B coincide.
[0067] According to the first embodiment, the adjustment amplitude R has a value included in a bounded interval [-X; +X] centered on zero. The maximum limit +X of the interval is thus equal to the opposite of the minimum limit -X of the interval. As illustrated by FIG. 3, the center distance E between the vision axis Av of each eyepiece 14A, 14B and the projection axis AP of the corresponding objective block 12 is equal to half + X of the positive limit +X of the bounded interval (maximum limit).
[0068] [Fig.4] illustrates three configurations obtained by rotating each eyepiece 14A, 14B around the corresponding projection axis AP, so as to obtain different adjustments of the interpupillary distance IPD. In particular, in this figure, the exit pupils Pi of the objective blocks 12 and the exit pupils P2 of the eyepieces 14A, 14B are also represented.
[0069] The middle configuration (average adjustment) corresponds to an average spacing for which the IPD spacing is equal to the nominal spacing N, the adjustment amplitude R being zero. In this configuration, the relative eccentricity of the eyepieces 14A, 14B is oriented vertically, and does not contribute to the adjustment of the IPD spacing. In the illustrated configuration, the eccentricity is oriented downwards. However, an upward eccentricity is also possible. When the binoculars 10 are fixed to a support that can be adjusted vertically (up-down), a translation of the binoculars 10 on its support makes it possible to compensate for the vertical eccentricity.
[0070] The left configuration corresponds to a minimum IPD spacing for which the adjustment amplitude R is equal to the lower limit -X of the bounded interval [-X; +X]. The IPD spacing is then equal to NX. Compared to the average adjustment (middle configuration), the eccentricity of each eyepiece 14A, 14B, relative to the corresponding objective block 12 14B is oriented inwards.
[0071] The right configuration corresponds to a maximum IPD spacing for which the adjustment amplitude R is equal to the upper limit +X of the bounded interval [-X; +X]. The IPD spacing is then equal to N+X. Compared to the average adjustment (middle configuration), the eccentricity of each eyepiece 14A, 14B, relative to the corresponding objective block 12 14B is oriented outwards.
[0072] Thus, the binoculars 10 according to the first embodiment have an asymmetry achieved by an eccentricity between the projection objectives and the corresponding eyepieces 14A, 14B, which allows inter-pupillary adjustment and the other advantages described for the general embodiment. Second embodiment
[0073] In the following, the specific features of the binoculars 10 according to the second embodiment are described with reference to FIGS. 1, 5 and 6.
[0074] As indicated previously, the binoculars 10 according to the second embodiment comprise two objective blocks 12 (one per eyepiece 14A, 14B). Such objective blocks 12 are advantageously identical.
[0075] In the specific example illustrated by [Fig.5], the input axis of each objective block 12 is non-coincident with the projection axis AP of the projection lens 26 of said objective block 12.
[0076] In particular, in this example, the input axis of each objective block 12 is offset from the projection axis AP of the corresponding projection objective 26 by a folding formed of two diopters L1, L2. In this example, each diopter L1, L2 has a flat optical surface which is parallel to the flat optical surface of the other diopter. Such folding is also called rhombohedron-type folding. The first diopter L1 is included in the capture objective 20 and is suitable for reflecting the captured and intensified image of the scene towards the second diopter L2. The second diopter L2 is included in the projection objective 26 and is on the path of the beam reflected by the first diopter LL
[0077] In this example, the flat optical surface of the second diopter L2 is partially reflective so as, on the one hand, to reflect the beam coming from the first diopter L1 and, on the other hand, to transmit the beam coming from the screen 24 so that the two beams are superimposed in the direction of the projection axis AP at the output of the second diopter L2. The first diopter L1 is, for example, a reflecting mirror.
[0078] Those skilled in the art will understand that the second embodiment is not limited to such a configuration of the objective blocks 12, and operates regardless of the configuration of the objective blocks 12. Thus, as a variant, the input axis of each objective block 12 is coincident with the projection axis AP of the projection lens 26 of said objective block 12, as is the case in the first embodiment.
[0079] According to the second embodiment and as illustrated by [Fig.5], each eyepiece 14A, 14B has an input axis coinciding with the projection axis AP of the corresponding objective block 12. The vision axis Av (exit axis) of each eyepiece 14A, 14B is offset from the input axis of said eyepiece 14A, 14B by a folding formed by two diopters L1', L2'. In this example, each diopter L1', L2' has a flat optical surface which is parallel to the flat optical surface of the other diopter. Such folding is also called rhombohedron-type folding. The input axis of the rhombohedron (and therefore of the eyepiece) is centered on the projection axis AP of the corresponding projection objective 26.
[0080] In particular, the first diopter L1' is positioned so as to be on the path of the projection beam FP at the output of the corresponding projection objective 26, and to reflect said projection beam FP in the direction of the second diopter L2'. The second diopter L2' is positioned so as to reflect said projection beam FP in the direction of the vision axis Av. In one example, the first diopter L1' and the second diopter L2' are reflecting mirrors.
[0081] In this second embodiment, the adjustment amplitude R is a function of: the center distance E between the projection axis AP and the vision axis Av of the corresponding eyepiece 14A, 14B, of a nominal orientation [3 of the eyepieces 14A, 14B, and of a rotation angle ap, an of each eyepiece 14A, 14B relative to the nominal orientation [3. The nominal orientation [3 is defined as being the angle between the plane comprising the two projection axes AP (right and left) and the axis of symmetry of the rhombohedron.
[0082]
[0083]
[0084]
[0085]
[0086]
[0087]
[0088]
[0089]
[0090]
[0091]
[0092]
[0093]
[0094] More precisely, the nominal spacing N is, for example, given by the following formula: N = D + ZETant / O Or: • D is the distance between the projection axes of the two objective blocks 12 (visible in [Fig.6]). The adjustment amplitude R is, for example, given by the following formula: 2E'.tan( when rotating the eyepieces 14A 14B outwards, or - 2£.tan( / 5 + an) when rotating the eyepieces 14A 14B inwards. Or: • ar is the angle of rotation of each eyepiece 14A, 14B relative to the nominal orientation [3 during a separation, and • an is the angle of rotation of each eyepiece 14A, 14B relative to the nominal orientation [3 during a rapprochement. The adjustment of the inter-pupillary setting is thus carried out by rotating each of the eyepieces 14A, 14B around the corresponding projection axis AP. In particular, in the medium adjustment position, the relative rotation of the plane of symmetry of the rhombohedrons of the eyepieces 14A, 14B with respect to the objective blocks 12 is oriented to the nominal orientation [3 (ap and an are null). In the maximum separation position, this rotation is oriented outwards along the angle [3-ap. In the minimum separation position, this rotation is oriented inwards along the angle [3+an. Thus, the binoculars 10 according to the second embodiment have an asymmetry achieved by a rhombohedral-type folding of the eyepieces 14A, 14B, which allows inter-pupillary adjustment and the other advantages described with the general embodiment. Compared with the first embodiment, the rotation amplitude of the eyepieces 14A, 14B, for adjusting the interpupillary distance, is reduced. In addition, aberrations are reduced because the overall optical system has rotational symmetry. Furthermore, in the second embodiment, the length of the binocular bodies 10 is reduced compared to conventional binocular in-line optics. As a result, the overhang of the helmet-mounted or head-harness-mounted binoculars 10 is reduced. Third embodiment In the following, the specific features of the binoculars 10 according to the third embodiment are described with reference to FIGS. 2, 7 and 8. As indicated previously, the binoculars 10 according to the third embodiment comprise a single objective block 12 which is therefore common to both eyepieces 14A, 14B. In particular, the projection axis AP is the rotation axis common to the two eyepieces 14A, 14B. The objective block 12 is, for example, an objective block according to one or other of the examples described for the first or third embodiment.
[0095] According to the third embodiment and as illustrated by [Fig.7], each eyepiece 14A, 14B has an input axis coinciding with the projection axis AP of the same objective block 12. The vision axis Av (exit axis) of each eyepiece 14A, 14B is offset from the input axis of said eyepiece 14A, 14B by a folding formed by two diopters: L1-A, L2-A for the eyepiece 14A and L1-B, L2-B for the eyepiece 14B. Each of the diopters L1-A, L2-A has a flat optical surface which is parallel to the flat optical surface of the other diopter L1-A, L2-A. Each of the diopters L1-B, L2-B has a flat optical surface which is parallel to the flat optical surface of the other diopter L1-B, L2-B. As for the second embodiment, such folds are rhombohedrons. The input axis of each rhombohedron is centered on the projection axis AP of the projection lens 26.
[0096] In particular, the flat optical surface of the first diopter L1-A of the first eyepiece 14A is partially reflective. The first diopter L1-A of the first eyepiece 14A is positioned so as to be on the path of the projection beam FP at the output of the projection objective 26 so as to reflect a portion of the projection beam FP in the direction of the second diopter L2-A of said first eyepiece 14A and to transmit the other portion in the direction of the first diopter L1-B of the second eyepiece 14B.
[0097] The second diopter L2-A of the first eyepiece 14A is positioned so as to reflect the projection beam FP coming from the first diopter L1-A in the direction of the axis of vision Av of the first eyepiece 14A. For example, the second diopter L2-A is a reflecting mirror.
[0098] The first diopter L1-B of the second eyepiece 14B is positioned so as to receive and reflect towards the second diopter L2-B of the second eyepiece 14B, the part of the beam transmitted by the first diopter L1-A of the first eyepiece 14A. For example, the first diopter L1-A is a reflecting mirror.
[0099] The second diopter L2-B of the second eyepiece 14B is positioned so as to reflect the projection beam FP coming from the first diopter L1-B of the second eyepiece 14B in the direction of the axis of vision Av of the second eyepiece 14B. For example, the first diopter L1-B is a reflecting mirror.
[0100] Advantageously, the center 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 reflecting faces of each rhombohedron) satisfies the following condition:
[0101] E + DI — D2 + E + D3
[0102] Where:
[0103]
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[0105]
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[0107]
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[0109]
[0110] [YES]
[0112] • DI is the distance, along the vision axis Av of the first eyepiece 14A, between the first diopter Ll-A and the focal point PA of the first eyepiece 14A, • D2 is the distance, along the projection axis AP, between the first diopter Ll-A of the first eyepiece 14A and the first diopter Ll-B of the second eyepiece 14B, and • D3 is the distance, along the vision axis Av of the second eyepiece 14B, between the second diopter Ll-B and the focal point PB of the second eyepiece 14B. In this third embodiment, the adjustment amplitude R is a function of: the center distance E between the projection axis AP and the vision axis Av of the corresponding eyepiece 14A, 14B, of a nominal orientation [3 of the eyepieces 14A, 14B, and of a rotation angle ap, an of each eyepiece 14A, 14B relative to the nominal orientation [3. More precisely, the nominal spacing N is, for example, given by the following formula: N = 2£.tan($) The adjustment amplitude R is, for example, given by the following formula: 2.E.tan( / ; - ap) when rotating the eyepieces 14A 14B outwards, or -2B;.tan(^ + a^when rotating the eyepieces 14A, 14B inwards. Or: • aP is the angle of rotation of each eyepiece 14A, 14B relative to the nominal orientation [3 during a separation, and • an is the angle of rotation of each eyepiece 14A, 14B relative to the nominal orientation [3 during a rapprochement. The adjustment of the inter-pupillary setting is thus carried out by rotating each of the eyepieces 14A, 14B around the corresponding projection axis AP. In particular, in the medium adjustment position, the relative rotation of the plane of symmetry of the rhombohedrons of the eyepieces 14A, 14B with respect to the objective blocks 12 is oriented to the nominal orientation [3 (ap and an are null). In the maximum separation position, this rotation is oriented outwards along the angle [3-ap. In the minimum separation position, this rotation is oriented inwards along the angle [3+an. Thus, the binoculars 10 according to the third embodiment make it possible to obtain a biocular vision device having an asymmetry with each eyepiece 14A, 14B, achieved by a rhombohedral-type folding of the eyepieces 14A, 14B. This allows inter-pupillary adjustment and the other advantages described for the general embodiment. Compared with the first embodiment, the rotation amplitude of the eyepieces 14A, 14B, for adjusting the interpupillary distance, is reduced. In addition, aberrations are reduced because the overall optical system has rotational symmetry.
[0113] Furthermore, in the third embodiment, the length of the binocular bodies 10 is reduced compared to conventional biocular in-line optics. As a result, the overhang of the helmet-mounted or head-harness-mounted binoculars 10 is reduced.
[0114] Those skilled in the art will understand that the embodiments described above are capable of being combined with each other when such combinations are compatible. In particular, the rhombohedron-type objective block 12 described in the second embodiment is compatible with the first and third embodiments. Similarly, the in-line objective block 12 described in the first embodiment is compatible with the second and third embodiments.
Claims
Claims
1. Night vision binoculars (10) comprising: a. at least one fixed objective block (12), the or each objective block (12) comprising: i. a capture lens (20) configured to capture an image of a scene, ii. a light intensifying device (22) configured to intensify the captured image to obtain an intensified image, iii. a screen (24) capable of generating an additional image, iv. a projection lens (26) configured to project the additional image onto the intensified image so that the output beam of the projection lens (26), called the projection beam (FP), carries the resulting image, the projection lens (26) having an output axis, called the projection axis (AP), the projection beam (FP) being a collimated or near-collimated beam, b. two image transport eyepieces (14A, 14B) receiving either the same projection beam (FP) when the binoculars (10) comprise a single objective block (12), or separate projection beams (FP) when the binoculars (10) comprise two objective blocks (12), each eyepiece (14A, 14B) having an output axis, called the axis of vision (Av), the axes of vision (Av) of the two eyepieces (14A, 14B) being parallel and separated by an adjustable distance, called the interpupillary distance (IPD), the axis of vision (Av) of each eyepiece (14A, 14B) being, in addition, parallel to the projection axis (AP) of the corresponding objective block (12) and having the same non-zero center distance (E) with the projection axis (AP) of the corresponding objective block (12), each eyepiece (14A, 14B) being rotatable relative to the projection axis (AP) of the corresponding objective block (12) so as to adjust the inter-pupillary distance (IPD).
2. Binoculars (10) according to claim 1, wherein the axis of view (Av) of each eyepiece (14A, 14B) is the optical axis of the eyepiece (14A, 14B).
3. Binoculars (10) according to claim 1 or 2, in which the binoculars (10) comprise two objective blocks (12), the interpupillary distance (IPD) being the sum of a nominal distance (N) and an adjustment amplitude (R), the value of the adjustment amplitude (R) being a function of the rotation of each eyepiece (14A, 14B) and being included in a bounded interval ([-X; +X]) centered on zero, the center distance (E) between the vision axis (Av) of each eyepiece (14A, 14B) and the projection axis (AP) of the corresponding objective block (12) being equal to half ( q. ^) of the positive terminal (+X) of the bounded interval.
4. Night vision binoculars (10) according to claim 1, wherein each eyepiece (14A, 14B) has an input axis coinciding with the projection axis (AP) of the corresponding objective block (12), the viewing axis (Av) of each eyepiece (14A, 14B) being offset from the input axis of said eyepiece (14A, 14B) by a folding formed by two diopters (LE, L2'; L1-A, L2-A, L1-B, L2-B), each diopter (LE, L2'; L1-A, L2-A, L1-B, L2-B) having a planar optical surface parallel to the planar optical surface of the other diopter (LE, L2'; L1-A, L2-A, L1-B, L2-B), the first diopter (LE; L1-A, L1-B) being configured to reflect in direction of the second diopter (L2'; L2-A, L2-B) at least a portion of the projection beam (FP) at the output of the corresponding objective block (12), the second diopter (L2'; L2-A, L2-B) being configured to reflect said projection beam (FP) in the direction of the axis of vision (Av).
5. Binoculars (10) according to claim 1 or 4, in which the interpupillary distance (IPD) is the sum of a nominal distance (N) and an adjustment amplitude (R) depending on the rotation of each eyepiece (14A, 14B), the adjustment amplitude (R) being a function of the center distance (E) between the projection axis (AP) and the vision axis (Av) of the eyepieces (14A, 14B), of a nominal orientation (|3) of the eyepieces (14A, 14B), and of an angle of rotation of each eyepiece (14A, 14B) relative to the nominal orientation (ap, an).
6. Binoculars (10) according to any one of claims 1 to 5, wherein the binoculars (10) comprise two objective blocks (12).
7. Binoculars (10) according to claim 4 or according to claim 5 as dependent on claim 4, in which the binoculars (10) comprise a single objective block (12) so that the projection axis (AP) is the common rotation axis of the two eyepieces (14A, 14B), the flat optical surface of the first diopter (L1-A) of one of the eyepieces, called the first eyepiece (14A), being partially reflective so as to reflect a part of the projection beam (FP) in the direction of the second diopter (L2-A) of said first eyepiece (14A) and to transmit the other part in the direction of the other eyepiece, called the second eyepiece (14B).
8. Binoculars (10) according to any one of claims 1 to 7, in which the or each objective block (12) comprises an input axis offset from the projection axis (AP) of the corresponding projection objective (26) by a folding formed of two diopters (L1, L2), each diopter (L1, L2) having a planar optical surface parallel to the planar optical surface of the other diopter (L1, L2), the first diopter (L1) being included in the capture objective (20), the second diopter (L2) being included in the projection objective (26) and being on the path of the beam reflected by the first diopter (L1).
9. Binoculars (10) according to any one of claims 1 to 8, in which the additional image is an image of the scene in a spectral band different from the spectral band of the image captured by the capture objective (20).