Observation device and associated sighting scope

Abstract

This device (4) for observing a scene comprises: - a camera (8); - a first display (10); - a second display (12); - an optical display combiner (14); - an arrangement of at least one optical component (18); and - an optical observation combiner (16); The optical display combiner (14) is provided with at least a first surface (14a) facing the first display (10) and a second surface (14b) facing the second display (12); At least one of the first and second surfaces (14a, 14b) of the optical display combiner (14) is a freeform surface.

Description

[0001] DESCRIPTION

[0002] TITLE: Observation Device and Associated Sighting Scope

[0003] technical field

[0004] The invention's technical domain is the superimposition of information onto an observed scene.

[0005] In particular, the present invention relates to an observation device and a sighting telescope comprising such an observation device.

[0006] The invention may also relate to augmented reality or head-up display equipment.

[0007] Previous techniques

[0008] Document ER 3 137 765 A1 describes a compact observation device that includes a camera, at least one micro-display, an optical combiner, and between one and three freeform optical surfaces configured to direct the information displayed by said micro-display to the optical combiner, the optical combiner directing the superposition of a scene observed by the device and the information displayed by said micro-display to an observation area.

[0009] Chromatic aberration can impair the performance of the observation device when it includes multiple microdisplays.

[0010] Description of the invention

[0011] The present invention aims to improve the optical quality of an observation device capable of superimposing information onto an observed scene.

[0012] The present invention relates to a scene observation device comprising:

[0013] - a camera;

[0014] - a first display configured to display an image of at least one spectral information measured by the camera;

[0015] - a second display configured to display a contextual image;

[0016] - an optical display combiner; - an arrangement of at least one optical component; and

[0017] - an optical observation combiner;

[0018] observation device in which:

[0019] - the optical display combiner is configured to combine the image displayed by the first display with the image displayed by the second display and to direct the combined image to the arrangement of at least one optical component;

[0020] - the arrangement of at least one optical component is configured to direct the combined image from the optical display combiner to the optical observation combiner;

[0021] - the optical observation combiner is configured to combine the image combined by the optical display combiner and directed by the arrangement of at least one optical component with an image from the observed scene and to direct the image thus combined towards an observation area; and

[0022] - the optical display combiner is provided with at least one first surface oriented towards the first display and a second surface oriented towards the second display.

[0023] According to a general characteristic, at least one of the first and second surfaces of the optical display combiner is a freeform type surface.

[0024] The said freeform surface oriented towards the corresponding display allows for the correction of the chromaticity of that display.

[0025] A "freeform surface" is defined as a surface lacking rotational symmetry around its local optical axis. Such a freeform surface is also called a "freeform" surface in English.

[0026] Advantageously, a plane comprising the local optical axis of the first surface of the optical display combiner and the local optical axis of the second surface of the optical display combiner forms a plane of symmetry of the optical combiner.

[0027] Preferably, the shape of the first surface of the optical display combiner is different from the shape of the second surface of the optical display combiner. According to a first design, the first surface of the optical display combiner which is oriented towards the first display is a freeform type surface and the second surface of the optical display combiner which is oriented towards the second display is not a freeform type surface.

[0028] Thus, we correct the chromaticism of the first display which generally has a higher field than the second display.

[0029] According to a second design, the first surface of the optical display combiner that is oriented towards the first display is not a freeform type surface and the second surface of the optical display combiner that is oriented towards the second display is a freeform type surface.

[0030] According to a third design, the first and second surfaces of the optical display combiner are freeform type surfaces.

[0031] Thus, the chromaticism of each of the first and second displays is corrected.

[0032] Optionally, the optical display combiner is provided with a third surface through which the image combined by the optical display combiner is transmitted, the third surface of the optical display combiner being a freeform type surface.

[0033] This further improves the optical quality of the observation device.

[0034] Optionally, the optical display combiner includes two prisms assembled together so that the overall shape of the optical display combiner is that of a rectangular parallelepiped.

[0035] This particular shape allows the optical display combiner to perform retrofocusing.

[0036] Each of the first and second surfaces of the optical display combiner can be generally rectangular in shape.

[0037] The display area of ​​each first and second display can be generally rectangular in shape.

[0038] Thus, the general shape of the optical combiner is adapted to the general shape of the displays. Preferably, the observation optical combiner comprises a first flat surface oriented towards the scene and a second flat surface oriented towards the observation area, the first and second flat surfaces of the observation optical combiner being parallel.

[0039] Thus, the stability of a line of sight of the observation device is improved.

[0040] Optionally, the optical observation combiner includes a freeform type surface which is arranged between the first and second planar surfaces of the optical observation combiner.

[0041] This further improves the optical quality of the observation device.

[0042] The optical combiner may comprise two complementary parts assembled together and a coating interposed between the two parts.

[0043] According to a particular embodiment, the arrangement of at least one optical component includes a prism having an input surface through which the image combined by the optical display combiner is transmitted, an intermediate surface against which the image transmitted by the input surface of the prism is reflected, and an output surface through which the image reflected by the intermediate surface of the prism is transmitted, each of the input, intermediate and output surfaces of the prism being of the freeform type.

[0044] Thus, the arrangement of at least one optical component is compact.

[0045] Advantageously, the camera is an infrared camera.

[0046] Advantageously, the first display emits electromagnetic radiation within a first band of wavelengths, the second display emitting electromagnetic radiation within a second band of wavelengths which is distinct from the first band of wavelengths.

[0047] The present invention also relates to a riflescope comprising an observation device as defined above. Brief description of the drawings

[0048] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0049] [Fig 1] illustrates a sighting scope according to a first example of an embodiment of the invention;

[0050] [Fig 2] illustrates light rays coming from a first display of the sighting scope in figure 1;

[0051] [Fig 3] illustrates light rays emanating from a second display of the sighting telescope in Figure 1; and

[0052] [Fig 4] illustrates an observation device according to a second embodiment of the invention.

[0053] Detailed description

[0054] Figure 1 shows a sighting telescope 2 comprising an observation device 4. The eye of an operator observing a scene through the sighting telescope 2 is also shown. The operator's eye is located in an observation zone 6.

[0055] The observation device 4 includes a camera 8, first and second displays 10, 12, optical display and observation combiners 14, 16, and an arrangement of at least one optical component 18.

[0056] Camera 8 is capable of acquiring images of the scene. Camera 8 is, for example, an infrared camera comprising an infrared lens, power supply electronics, image processing electronics, and an infrared sensor.

[0057] The first display 10, for example a first microdisplay, is capable of displaying the images of the scene acquired by the camera 8.

[0058] The image processing electronics is capable of implementing image processing so that the first display 10 shows only a part of the spectral information measured by the camera 8. The second display 12, for example a second microdisplay, is capable of displaying a contextual image, for example a red dot or a reticle.

[0059] The optical display combiner 14 is capable of combining, in particular superimposing, the image displayed by the first display 10 with the image displayed by the second display 12. The optical display combiner 14 is also capable of directing the image thus combined towards the arrangement of at least one optical component 18.

[0060] The arrangement of at least one optical component 18 is suitable for directing the image which has been combined by the optical display combiner 14 towards the optical observation combiner 16.

[0061] The optical observation combiner 16 is capable of combining, in particular superimposing, the image that has been combined by the optical display combiner 14 and then directed by the arrangement of at least one optical component 18 with an image from the observed scene. The image from the observed scene is an image along a direct optical path extending between the observation area 6, in particular the operator's eye, and the observed scene. The optical observation combiner 16 is also capable of directing the combined image to the observation area 6.

[0062] The optical display combiner 14 is here a splitter pad. The optical display combiner 14 comprises, for example, two prisms assembled together to form the splitter pad. Thus, the general shape of the optical display combiner 14 is that of a rectangular parallelepiped.

[0063] The optical display combiner 14 comprises six external surfaces, including a first surface 14a oriented towards the first display 10, a second surface 14b oriented towards the second display 12 and a third surface 14c through which the image combined by the optical display combiner 14 is transmitted.

[0064] The first and second surfaces 14a, 14b of the optical display combiner 14 are freeform surfaces. Alternatively, only one of the first and second surfaces 14a, 14b of the optical display combiner 14 could be a freeform surface.

[0065] The arrangement of at least one optical component 18 here includes a prism 20. More precisely, the arrangement of at least one optical component 18 here consists of the prism 20.

[0066] The prism 20 includes an input surface 20a through which the combined image from the optical display combiner 14 is transmitted and directed towards the prism 20, an intermediate surface 20b against which the combined image from the optical display combiner 14 is reflected and then transmitted through the input surface 20a of the prism 20, and an output surface 20c through which the combined image from the optical display combiner 14 is transmitted through the input surface 20a of the prism 20 and then reflected through the intermediate surface 20b of the prism 20.

[0067] Each of the inlet, intermediate and outlet surfaces 20a, 20b, 20c of prism 20 is of the freeform type.

[0068] The optical observation combiner 16 includes a beam splitter. More specifically, the optical observation combiner 16 comprises a first flat surface 16a oriented towards the scene and a second flat surface 16b oriented towards the observation area 6. The first and second flat surfaces 16a, 16b of the optical observation combiner 16 are parallel. The first and second flat surfaces 16a, 16b of the optical observation combiner 16 may include, for example, a thin-film dielectric coating such that the first and second flat surfaces 16a, 16b of the optical observation combiner 16 are treated with an anti-reflective coating.

[0069] As illustrated in Figure 2, the first display 10 emits electromagnetic radiation which is transmitted by the first surface 14a of the optical display combiner 14, then transmitted by the third surface 14c of the optical display combiner 14, then transmitted by the input surface 20a of the prism 20, then reflected by the intermediate surface 20b of the prism 20, then transmitted by the output surface 20c of the prism 20, then reflected by the second flat surface 16b of the optical observation combiner 16 and finally directed towards the observation area 6.

[0070] As illustrated in Figure 3, the second display 12 emits electromagnetic radiation which is transmitted by the second surface 14b of the optical display combiner 14, then transmitted by the third surface 14c of the optical display combiner 14, then transmitted by the input surface 20a of the prism 20, then reflected by the intermediate surface 20b of the prism 20, then transmitted by the output surface 20c of the prism 20, then reflected by the second flat surface 16b of the optical observation combiner 16 and finally directed to the observation area 6.

[0071] The electromagnetic radiation emitted by the first display 10 is contained within a first band of wavelengths. The electromagnetic radiation emitted by the second display 12 is contained within a second band of wavelengths which is distinct from the first band of wavelengths.

[0072] The electromagnetic radiation emitted by the first display 10 passes through the first surface 14a of the optical display combiner 14 and does not pass through the second surface 14b of the optical display combiner 14.

[0073] The electromagnetic radiation emitted by the second display 12 passes through the second surface 14b of the optical display combiner 14 and does not pass through the first surface 14a of the optical display combiner 14.

[0074] Thus, the first and second surfaces 14a, 14b of the optical display combiner 14 make it possible to correct the chromaticism induced by the difference in electromagnetic radiation emitted by the first and second displays 12.

[0075] The embodiment illustrated in Figure 4 differs from the embodiment illustrated in Figures 1 to 3 in that the third surface 14c of the optical display combiner 14 is a freeform type surface and in that the optical observation combiner 16 includes a freeform type surface 16c which is arranged between the first and second planar surfaces 16a, 16b of the optical observation combiner 16.

[0076] In the illustrated embodiments, the arrangement of at least one optical component 18 consists of the prism 20. Alternatively, it could be envisaged that the arrangement of at least one optical component 18 includes an arrangement of mirrors and lenses, in particular as described by document FR 3 137 765 Al.

Claims

DEMANDS 1. Observation device (4) for a scene comprising: - a camera (8); - a first display (10) configured to display an image of at least one spectral information measured by the camera (8); - a second display (12) configured to display a contextual image; - an optical display combiner (14); - an arrangement of at least one optical component (18); and - an optical observation combiner (16); observation device (4) in which: - the optical display combiner (14) is configured to combine the image displayed by the first display (10) with the image displayed by the second display (12) and to direct the image thus combined to the arrangement of at least one optical component (18); - the arrangement of at least one optical component (18) is configured to direct the combined image from the optical display combiner (14) to the optical observation combiner (16); - the optical observation combiner (16) is configured to combine the image combined by the optical display combiner (14) and directed by the arrangement of at least one optical component (18) with an image from the observed scene and to direct the image thus combined towards an observation area (6); and - the optical display combiner (14) is provided with at least a first surface (14a) oriented towards the first display (10) and a second surface (14b) oriented towards the second display (12) characterized in that at least one of the first and second surfaces (14a, 14b) of the optical display combiner (14) is a freeform type surface, the shape of the first surface (14a) of the optical display combiner (14) being different from the shape of the second surface (14b) of the optical display combiner (14).

2. Observation device (4) according to claim 1, wherein the first and second surfaces (14a, 14b) of the optical display combiner (14) are freeform type surfaces.

3. Observation device (4) according to claim 1 or 2, wherein the optical display combiner (14) is provided with a third surface (14c) through which the image combined by the optical display combiner (14) is transmitted, the third surface (14c) of the optical display combiner (14) being a freeform type surface.

4. Observation device (4) according to any one of claims 1 to 3, wherein the optical display combiner (14) comprises two prisms assembled together so that the general shape of the optical display combiner (14) is that of a rectangular parallelepiped.

5. Observation device (4) according to any one of claims 1 to 4, wherein the optical observation combiner (16) comprises a first flat surface (16a) oriented towards the scene and a second flat surface (16b) oriented towards the observation area (6), the first and second flat surfaces (16a, 16b) of the optical observation combiner (16) being parallel.

6. Observation device (4) according to claim 5, wherein the optical observation combiner (16) comprises a freeform type surface (16c) which is arranged between the first and second planar surfaces (16a, 16b) of the optical observation combiner (16).

7. Observation device (4) according to any one of claims 1 to 6, wherein the arrangement of at least one optical component (18) comprises a prism (20) having an input surface (20a) through which the image combined by the optical display combiner (14) is transmitted, an intermediate surface (20b) against which the image transmitted by the input surface (20a) of the prism (20) is reflected, and an output surface (20c) through which the image reflected by the intermediate surface (20b) of the prism (20) is transmitted, each of the input, intermediate and output surfaces (20a, 20b, 20c) of the prism (20) being of the freeform type.

8. Observation device (4) according to any one of claims 1 to 7, wherein the camera (8) is an infrared camera.

9. Observation device (4) according to any one of claims 1 to 8, wherein the first display (10) emits electromagnetic radiation included in a first band of wavelengths, the second display (12) emitting electromagnetic radiation included in a second band of wavelengths which is distinct from the first band of wavelengths.

10. Sighting telescope (2) comprising an observation device (4) according to any one of claims 1 to 9.

Images