FR2995448A1 - Optical recording device for use in e.g. leisure applications for recording scene, has deflectors for deflecting light rays from regions of scene to detecting surface to optically superimpose regions of scene on detecting surface - Google Patents

Abstract

The invention relates to an optical pickup device (1) configured for shooting a scene (9) comprising N zones (10), said device (1) being characterized in that it comprises: a surface (7) for detecting light rays, - a plurality of N optical deflectors (3) disposed in a pupil (4, 5) of the optical device (1), said optical deflectors (3) being configured to deflect radii light from the N zones (10) of the scene (9) to the detection surface (7), o to optically superpose the N zones (10) of the scene (9) on the detection surface (7).

Description

GENERAL TECHNICAL FIELD The invention relates to an optical device for shooting a scene and a method for detecting characteristic elements in said scene. The invention also relates to an optical light emitting device based on a configuration similar to the optical shooting device. STATE OF THE ART The observation of scenes requires an optical device for shooting. A classic constraint in the field of observation is to cover a scene as wide as possible. If a scene has N areas to observe, there are several conventional solutions to observe these N areas.

One solution is to use N distinct detection surfaces, placed at the focal plane of the optical device, each detection surface being able to detect light rays coming from one of the N zones to be observed. This solution has the disadvantage of multiplying the number of detection surfaces, and therefore the complexity and the cost of the instrumental device. Another solution is to use N distinct detection surfaces associated with N distinct objectives. This solution is also expensive, bulky, and difficult to implement since it relies on the multiplication of sensors and optical elements. Finally, another solution is to use a scanning mirror, or scan mirror, or change of sighting mirror, to observe sequentially the N zones. The mirror makes it possible to deflect sequentially the light rays coming from one of the N zones, which makes it possible to scan, after a given observation time, the whole of the scene.

This solution has several disadvantages. On the one hand, it necessarily implies a sequential observation of the zones of the scene, and therefore a long observation time. On the other hand, a scanning mirror is complex and difficult to implement.

It should be noted that the drawbacks encountered in the field of observation of scenes comprising a plurality of zones are found in the light-emitting devices intended to illuminate such scenes. For example, one may want to illuminate a plurality of areas of a scene while retaining a simple device to implement and effective. In this context, the technical solution proposed in this invention makes it possible to improve the optical imaging devices known from the state of the art, whether they are optical devices for taking a view of a scene comprising multiple areas, or light emitting optical devices to multiple directions. PRESENTATION OF THE INVENTION The invention aims to overcome, at least in part, the aforementioned drawbacks of the state of the art. For this purpose, the invention proposes an optical shooting device, configured for shooting a scene comprising N zones, said device being characterized in that it comprises: a surface for detecting light rays, A plurality of N optical deflectors disposed in a pupil of the optical device, said optical deflectors being configured to deflect light rays from the N zones of the scene towards the detection surface, in order to optically superimpose the N zones of the scene on the detection surface. The invention is advantageously complemented by the following characteristics, taken alone or in any of their technically possible combination: the optical deflectors are prisms or mirrors; the optical deflectors are arranged in an entrance pupil of the optical device; the device further comprises an optical image selection module, interposed between the optical deflectors and the detection surface, said optical module being configured to transmit only light rays deviated by a part or the whole of a subset optical baffles to the sensing surface, said subassembly comprising N1 deflectors, with N1 strictly less than N, for optically superimposing only a subset of areas of the scene optically on the sensing surface; the optical module is able to vary the subset of N1 deflectors over time; the optical module is disposed in a pupil of the optical device; the optical module is chosen from a shutter, or a prism, or a liquid crystal system, or a set of mirrors. The invention also relates to an optical light emitting device, configured for the illumination of a scene comprising N zones, said device being characterized in that it comprises: a source of emission of light rays, a plurality of N optical deflectors disposed in a pupil of the optical device, said optical deflectors being configured to deflect light rays from the light source to the areas of the scene, - an optical module, interposed between the source and the optical deflectors said module being configured to transmit light rays emitted by the light source only to a subset of N1 optical deflectors, N1 being strictly less than N, for illumination of a subset of the areas of the scene.

This optical light-emitting device is advantageously completed by the following features, taken alone or in any of their technically possible combination: the source comprises a plurality of distinct light-emitting elements; optical deflectors are prisms or mirrors; the optical deflectors are arranged in a pupil of the optical device; the optical module is able to vary the subset of N1 deflectors over time; the optical module is disposed in a pupil of the optical device; the optical module is chosen from a shutter, or a prism, or a liquid crystal system, or a set of mirrors.

The invention also relates to a detection method implementing the optical device for shooting a previously described scene, said scene comprising at least one characteristic element, said method being characterized in that it comprises: a step of of obtaining images via the optical device, consisting of transmitting, via the optical module, only light rays deviated by a part or the whole of a subset of N1 optical deflectors towards the surface of detection, N1 being strictly less than N, in order to optically superpose on the detection surface only a subset of areas of the scene, - a step of identifying the characteristic element, and - a step of varying the over time, through the optical module, the deflectors belonging to the subset of N1 deflectors, in order to identify and / or locate the element feature. The invention has many advantages.

An advantage of the invention is to provide an optical device that is simple to implement. Another advantage of the invention is to propose an optical device having an increased field of view.

Another advantage of the invention is to propose a device that is less expensive than some devices of the state of the art. In particular, the invention does not require a multiplication of detection surfaces or the use of a larger detector whose feasibility and cost may be critical, or the use of delicate and complex optical mechanisms. Finally, another advantage of the invention is to propose an optical device configuration that can be adapted both to the emission of light rays and to the detection of light rays. PRESENTATION OF THE FIGURES Other features, objects and advantages of the invention will emerge from the description which follows, which is purely illustrative and nonlimiting, and which should be read with reference to the appended drawings, in which: FIG. diagram of an embodiment of an optical shooting device according to the invention; - Figure 2 is a diagram of an embodiment of optical deflectors according to the invention, in the case of a device with four baffles and square optical pupil; FIG. 3 is a diagram of an embodiment of an optical pickup device comprising an optical module for selecting images according to the invention; FIG. 4 is a diagram of steps of a detection method according to the invention; Figure 5 is a diagram of a scene including a characteristic element to be detected; - Figure 6 is a diagram of an embodiment of an optical light emitting device according to the invention.

DETAILED DESCRIPTION FIG. 1 shows an embodiment of an optical imaging device 1 according to the invention. This device 1 is configured for shooting a scene 9 comprising N distinct areas. In Figure 1, there is shown the case where N is equal to four. The optical device 1 comprises a surface 7 for detecting light rays. The detection surface 7 is placed in the focal plane of the optical device 1. This is typically a surface comprising light sensitive pixels, for example, but not limited to, matrix detector type. The optical device 1 further comprises a plurality of N optical deflectors 3 disposed in a pupil of the optical device 1, N being greater than or equal to two. In Figure 1, the optical deflectors 3 are placed in the entrance pupil 4 of the optical device 1. It is recalled that the geometric extent of the light beam transmissible by an optical device is limited by an aperture diaphragm 20, and defines the solid angle of the useful beam emitted by a point of the scene to be observed (for example, the point of the scene located on the optical axis of the device). The respective images of the aperture diaphragm in the upstream (object) and downstream (image) spaces of the optical device are referred to as the input and output pupils of the device. The exit pupil is the conjugation of the entrance pupil by the optical device. The optical device also includes pupils, called intermediate pupils. Indeed, the optical device typically comprises a number of optical elements (see reference 12 in Figure 1), such as lenses. The image of the entrance pupil by each optical element gives an intermediate pupil. In Figure 1, there is shown an intermediate pupil 13. The optical deflectors 3 are configured to deflect light rays from the N zones 10 of the scene 9 to the optical surface 5 in order to optically superimpose the N zones 10 of the scene 9 on the surface 7 detection. In the end, the detection surface 7 receives the superposition of the images coming from the N zones 10 of the scene 9. Each pixel of the detection surface therefore observes at each instant several objects (N objects). As can be understood, the optical deflectors 3 make it possible to extend the field of view of the optical device 1 by deflecting the light rays and superimposing them on the detection surface 7. Each optical deflector 3 has a different orientation vis-à-vis the optical axis 14 of the optical device 1, which allows to recover light rays from different areas of the scene. The set of N optical deflectors 3 is a decomposition of the entrance pupil 4 of the optical device 1 in as many sub-pupils, a deflector being associated with each sub-pupil. Each zone 10 of the scene 9 is imaged on the common detection surface 7 of the optical device 1 by the deflection of one of these deflectors. Each zone 10 to be observed has a dedicated optical deflector. Thus, the proposed solution provides a significant time gain for access to information in each area. The optical device 1 further comprises, and conventionally, a succession of lenses or optical elements 12 adapted to the needs of the observation. Advantageously, but not exclusively, optical deflectors 3 are prisms. In this case, it is therefore a means of deflection by transmission. This solution is illustrated in Figure 2, with four prisms for deflecting light rays from four areas of a scene. These prisms are schematized in perspective (view (A)), and in side view (view (B)). In the embodiment illustrated in FIG. 2, the prisms produce a square geometry entrance pupil. This is not mandatory and other geometries are possible. Advantageously, but not exclusively, the optical deflectors 3 can be mirrors. It is then in this case deflection means by reflection. Other technical solutions are conceivable for the 3 optical deflectors 3. In particular, their number and their geometry are not limited to a particular solution. As can be understood, the optical device 1 makes it possible to cover a scene 9 comprising a plurality of zones 10, and this with a single detection surface 7. This eliminates the costs and the constraints associated with the multiplication of the sensors and the scanning mirror mechanisms of the state of the art. A significant simplification of the optical device is thus obtained. In addition, an optical device having an increased field of view is obtained. Thus, with an optical and a given detection surface, the field of view is increased. This increase in the field of view for a device equipped with a single detection surface is also valid and interesting for a device whose focal plane 7 is composed of several detectors. In one embodiment, the optical device 1 as previously described further comprises an optical image selection module 11 interposed between the optical deflectors 3 and the detection surface 7. This optical module 11 is shown in FIG. 3. The optical module 11 is configured to transmit light rays in a time-varying manner. This is a module for closing a subset of optical deflectors 3. This closure of each subset may be total or partial. Thus, a total shutter corresponds to a shutter of all the deflectors of the subassembly, while a partial shutter corresponds to a shutter of only a part of the subset of deflectors (for example only certain deflectors of the subset, or an area comprising several portions of the deflectors of the subassembly). This shutter is variable in time. The deflector subassembly comprises N1 deflectors with N1 strictly smaller than N, in order to optically superimpose only a subset of the zones of the scene 9 on the detection surface 7.

In general, therefore, we have l <Ni <N, the case N1 equal to zero corresponding to a zero transmission of light rays by the optical module 11. Thus, the optical module 11 is configured to transmit only light rays deflected by a portion or all of a subset of the optical deflectors 3 to the detection surface 7, said subset comprising N1 deflectors. For example, the optical module 11 can be configured to transmit light rays coming from a single deflector at a time (N1 = 1), and therefore from a single zone, said module being configured to vary over time the deflector whose light rays are transmitted to the optical surface 7, which makes it possible to scan the zones of the scene one by one. Advantageously, the optical module 11 is configured to transmit only light rays deflected by a subset of N1 optical deflectors 3 towards the detection surface 7, said sub-assembly N1 being variable over time. Thus, the optical module 11 is able to vary the subset of N1 deflectors over time. In this case, the optical module 11 makes it possible to temporally select areas of the scene to be superimposed on the detection surface 7. In the case of partial shutter, each subset is not completely closed at each image taking. On the other hand, the partial occultation makes the luminous flux variable and makes it possible to identify the subset concerned by a given signal. In this case, the shutter can be in continuous rotation. The optical module 11 is placed in a pupil of the optical device. It is advantageous to arrange the optical module 11 in the exit pupil 5 of the optical device 1. This makes it possible to reduce the size of the optical module 11, since the optical module is close to the focal plane of the optical device 1. However, the optical module 11 may be disposed in the entrance pupil 4 of the optical device 1, or in an intermediate pupil of the optical device 1. Various embodiments of the optical module 11 are conceivable. It may for example be a shutter, advantageously movable in rotation or in translation, a shutter with a given occultation geometry, a shutter with scanning or rotation, a liquid crystal system, a prism, a component MOEMS (Microsystem opto-electromechanical) matrix type of micro-mirrors, etc. Depending on the number of zones to be imaged on the detection surface 7, the geometry of the optical module 11 must be adapted. The invention also relates to a detection method using the optical device for shooting a scene comprising such an optical module (see FIG. 4). It is a question of detecting a characteristic element in the scene (see Figure 5). The characteristic signature of this element can be its movement, its signal level, its geometry, and so on. For example, the passage of an airplane can be detected in the field of air traffic control. The characteristic element 30 may correspond to a moving phenomenon or a static phenomenon. The method comprises a step El of obtaining images via the optical device 1. Step E1 consists of transmitting, via the optical module 11, only light rays deviated by a part or the whole of a subset of N1 optical deflectors 3 towards the detection surface 7, N1 being strictly inferior at N, in order to optically superimpose on the detection surface 7 only a subset of areas of the scene 9. The method comprises a step E2 of identifying the characteristic element. The detection of the characteristic element on each of the images is obtained by conventional image processing: filtering or processing to detect a characteristic structure, comparison of images to detect a movement, or detection of intensity threshold. The method comprises a step E3 of varying over time, through the optical module 11, the deflectors belonging to the subset of N1 deflectors. The successive acquisition of the images of a superposition of N1 zones of the scene 9 makes it possible, by comparison between the images of the series, to determine the origin and to locate a characteristic element. In an advantageous embodiment, N1 is chosen as equal to 1. Thus, one can successively image each zone of the scene. In another advantageous embodiment, N1 is chosen to be equal to N-1. Thus, N-1 scenes are superimposed at any time. The invention has heretofore been described with reference to an optical image pickup device. The invention applies similarly to the case of an optical light emitting device 20, in which the aforementioned detection surface 7 is replaced by a source 22 for light emission. The direction of propagation of the light is therefore reversed with respect to the previous embodiments, but the principle and the means used are similar. The optical light emitting device 20 is configured for illumination of a scene 21 comprising zones 26.

The device 20 comprises a source 22 for emitting light rays. It is advantageously a source 22 comprising a plurality of distinct light emitting elements 29, for example an array of LEDs. It can also be a single source 22.

The device 20 further comprises a plurality of N optical deflectors 23, said optical deflectors 23 being configured to deflect light rays from the light source 22 towards zones 26 of the scene 21. The device 20 further comprises an optical module 27 interposed between the source 22 and the optical deflectors 23. The optical module 27 is configured to transmit light rays emitted by the light source 22 only to a subset of N1 optical deflectors 23, N1 being strictly less than N, for the illumination of a subset of the zones 26 of scene 21. The optical module 27 is identical to the optical module 11 previously described. Similarly, the optical deflectors 23 may be identical to those described above (optical deflectors 3). Thus, the optical deflectors 23 are, for example, prisms or mirrors. The optical deflectors 23 are disposed in a pupil of the optical device 20, advantageously in an entrance pupil 24 of the optical device 20. Advantageously, the module 27 is configured to transmit only a subset of the light rays emitted by the light source to the optical deflectors, and said subset is variable over time. The module 27 is also disposed in a pupil of the optical device 20. Advantageously, the optical module 27 is disposed in an entrance pupil 24 or an exit pupil 25 of the optical device.

As already stated, various embodiments of the optical module 27 are conceivable. It may for example be a shutter movable in rotation or in translation, a liquid crystal system, a prism, a component 5 MOEMS matrix type of micro-mirrors, etc. This optical light emitting device has many applications. For example, it is possible, thanks to the light-emitting optical device of the invention, to have a very compact optical projector capable of illuminating N zones of a scene with a given (objective) optics which was able to illuminate only one of these areas in the prior art. An increase in the field of view of the optical device is thus obtained. Another example of application relates to a projector with light and / or variable color.

On the one hand, the number of focal plane light emitting elements 29, the geometry and the sequence of the optical module make it possible to create specific light effects. In particular, the use of a light-emitting source in the light-emitting optical device, said light-emitting source comprising light-emitting elements programmable in transmission, color, or other, allows you to create directional lighting effects and desired colors. We can create a kaleidoscope. The light emitting elements are advantageously an array of LEDs. The optical device is an integrated device, without complex mechanism, and can be used both in the field of entertainment and in the industrial field. The invention has many advantages, both for the emission of light rays and the detection of light rays.

Claims (4)

REVENDICATIONS1. An optical recording device (1) configured for shooting a scene (9) comprising N regions (10), said device (1) being characterized by comprising: - a surface (7) ) a plurality of N optical deflectors (3) disposed in a pupil (4, 5) of the optical device (1), said optical deflectors (3) being configured to deflect light rays from N zones (10) of the scene (9) towards the detection surface (7), o to optically superpose the N zones (10) of the scene (9) on the detection surface (7). 15 2. Device according to claim 1, wherein the optical deflectors (3) are prisms or mirrors. 3. Device according to one of claims 1 or 2, wherein the optical deflectors (3) are disposed in an entrance pupil (4) of the optical device (1). 4. Device according to one of claims 1 to 3, further comprising - an optical module (11) for selecting images, interposed between the optical deflectors (3) and the detection surface (7), 25 o said module (11) optical configured to transmit only light rays deviated by a portion or all of a subset of the optical deflectors (3) to the detection surface (7), said subassembly comprising N1 deflectors, with N1 strictly less than N, 30 o in order to optically superpose on the detection surface (7) only a subset of zones of the scene (9). . Device according to claim 4, wherein the optical module (11) is able to vary the subset of N1 deflectors over time. 6. Device according to one of claims 4 or 5, wherein the optical module 5 (11) is disposed in a pupil of the device (1) optical. 7. Device according to one of claims 4 to 6, wherein the optical module (11) is selected from: - a shutter, or - a prism, or - a liquid crystal system, or - a set of mirrors. An optical light emitting device (20) configured for illumination of a scene (21) comprising N areas (26), said device (20) being characterized in that it comprises: - a source (22) for emitting light rays, - a plurality of N optical deflectors (23) disposed in a pupil (24, 25) of the optical device (20), wherein said optical deflectors (23) are configured to deflect the rays. light source from the light source (22) towards the zones (26) of the stage (21), - an optical module (27) interposed between the source (22) and the optical deflectors (23), wherein said module (22) 27) being configured to transmit light rays emitted from the light source (22) only to a subset of N1 optical deflectors (23), N1 being strictly less than N, for illumination of a subset of the zones (26) of the scene (21). The device of claim 8, wherein the source (22) comprises a plurality of distinct light emitting elements. 10. Device according to one of claims 8 or 9, wherein the 5 deflectors (23) optics are prisms or mirrors. 11. Device according to one of claims 8 to 10, wherein the optical deflectors (23) are disposed in a pupil (24) of the device (20) optical. 12. Device according to one of claims 8 to 11, wherein the optical module (27) is adapted to vary the subset of N1 deflectors over time. 13. Device according to one of claims 8 to 12, wherein the optical module (27) is disposed in a pupil (24) of the device (20) optical. 14. Device according to one of claims 8 to 13, wherein the optical module (27) is selected from: - a shutter, or - a prism, or - a liquid crystal system, or - a set of mirrors. 15. Detection method using the optical device (1) for shooting a scene according to one of claims 4 to 7, said scene comprising at least one characteristic element (30), said method being characterized in that it comprises: - a step (El) for obtaining images via the optical device (1), consisting of transmitting, via the optical module (11), only light rays deviated by a part or all of a subset of N1 optical deflectors (3) towards the detection surface (7), N1 being strictly less than N, in order to optically superpose on the detection surface (7) only a subset of zones of the scene (9), - a step (E2) of identification of the element (30) characteristic, and - a step (E3) of varying over time, via the module ( 11) optics, the deflectors belonging to the subset of N1 deflectors, in order to identifying and / or locating the characteristic element (30).