Image-acquisition device for road control automatons

Abstract

The invention relates to an image-acquisition device (1000) comprising: - a photosensitive sensor support (1001) provided with a motorised rotary shaft (1002) which is oriented substantially perpendicularly to the surface (1001a) of the support (1001); - a photosensitive sensor (1003) attached to the support (1001) so as to be substantially parallel to the surface (1001a) of the support (1001); and - a polarising filter (1004) attached to the motorised rotary shaft and of a size which is suitable for covering the active surface (1003a) of the photosensitive sensor (1003); - the motorised rotary shaft (1002) is configured to pivot the polarising filter (1004) into a filtering position (PF) so as to cover the active surface (1003a) of the photosensitive sensor (1003) by means of the polarising filter (1004) and into a release position (PL) so as to expose the active surface (1003a) of the photosensitive sensor (1003) when it is covered by the polarising filter (1004).

Description

Description Title of the invention: Image acquisition device for road control machines Technical field [1] The present invention relates to an image acquisition device for a road control machine. Technical background [2] It is common practice to control or monitor road traffic using automated systems comprising speed cameras - radar or laser devices for measuring the speed and position of vehicles - and optical systems configured to acquire images of the interior and / or exterior of vehicles. These automated systems are programmed to detect and characterize certain road traffic offenses committed by vehicle drivers through the combined analysis of the signals from the speed cameras and the acquired images. In particular, they make it possible to produce elements of typing and proof of the offense, and to extract from the images information such as registration numbers allowing the identification of the perpetrator of the offense for the purpose of drawing up a report. [3] The reliability of these machines is based in part on the acquisition of images whose quality allows identification of the elements relevant to the characterization of the offense. This identification must not suffer from any ambiguity whatever the light or weather conditions in which these images are acquired. It is therefore essential that the optical systems of the road control machines offer, day and night, in good weather or in bad weather, the best optical performance to ensure perfect concordance between the data from the speed cameras and the images acquired by these systems for each vehicle checked. [4] EP 2 690 459 A2, JENOPTIK ROBOT GMBH [DE], 29.01 .2014 describes a road traffic control machine comprising a radar or laser speed camera and two cameras, one of which is a high-resolution camera. The speed camera and the two cameras are arranged in such a way that their respective optical fields overlap. The automaton includes a data processing unit configured to identify objects in the images acquired by the two cameras and compare their positions with those measured by the speedometer. [5] EP 3 012 652 A1, MORPHO [FR], 27.04.2016 describes a road control unit comprising a speed camera and optical devices mechanically assembled together using a plate. The plate comprises fixings for holding the optical devices in a certain angular orientation relative to a radioelectric axis of the speed camera. This unit simplifies its installation and improves the accuracy of its adjustment to ensure concordance between the vehicle controlled by the speed camera and that appearing on the images acquired by the optical devices. [6] FR 3 109 462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021 describes a road surveillance automaton capable of acquiring quality images of the interior of a vehicle, day and night. This automaton comprises several photosensitive sensors. Each photosensitive sensor is equipped with an optical objective with a lens and a polarizing filter mounted in a removable and movably manner in front of said lens. The polarizing filter makes it possible to attenuate, or even eliminate, the glare of the photosensitive sensors by possible specular reflections of light on the reflective walls of the vehicles. It is fixed on a motorized rotating axis configured to pivot it alternately into a so-called filtering position so as to cover the surface of the lens of the optical objectives, and into a so-called release position so as to uncover the lens when it is covered by said polarizing filter. Summary of the invention Technical problem [7] There is now a need to reduce the spatial footprint of automatons in order to make them not only more discreet but also to deploy them in road environments whose topographical characteristics present constraints in terms of positioning and free space. This is particularly the case for urban or peri-urban road spaces. Compact automatons are also advantageous in facilitating their transport, maintenance and handling. [8] However, a first drawback of the automaton described in FR 3 109 462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021 is the spatial bulk of the assembly formed by the optical lenses and the polarizing filters. A clearance space must be provided around the end of the optical lenses when the filters are in the release position, that is to say when they are pivoted so as to uncover their lenses. The size of the polarizing filters varies with that of the optical lenses, in particular with that of their lenses. The larger the optical lenses, the larger the filters. The clearance space must then be all the larger as the optical lenses are, and the arrangement of such a space can quickly become a technical constraint that is difficult to reconcile with the other constituent elements of the automaton.This is particularly the case when the PLC is used to control a remote road lane or several road lanes in spaces simultaneously where several large high-resolution objectives may be required. [9] A second disadvantage is that, depending on the size of the polarizing filters, the size of the rotary axis and the motorization must be adapted accordingly. For example, in the same automaton, a first polarizing filter larger than a second may require, during a change of position, a different movement speed than that used by the second.

[0010] A third drawback is the need to provide polarizing filters of different sizes adapted to the size of each optical lens. The number of parts - polarizing filters, rotary axes, motors - required for the assembly of the machine or for maintenance operations, for example in the case of filter changes, can become a logistical constraint for operators, particularly with regard to the availability of said parts. Technical solution

[0011] In a first aspect of the invention, there is described an image acquisition device as described in claim 1, the dependent claims being advantageous embodiments.

[0012] In a second aspect of the invention, a system is described comprising an acquisition device according to the first aspect of the invention.

[0013] In a third aspect of the invention, a use of an optical system according to the second aspect of the invention in a road control machine is described. Brief description of the drawings

[0014] Fig. 1 is a schematic perspective representation of an image acquisition device according to the first aspect of the invention.

[0015] Fig. 2 is a schematic representation in front view of the device of Fig. 1

[0016] Fig. 3 is a schematic sectional representation along plane III-III of the device of Fig. 2.

[0017] Fig. 4 is a schematic representation, front view, of the device of Fig. 1 in the filtering position.

[0018] Fig. 5 is a schematic sectional representation along plane VV of the device of Fig. 4.

[0019] Fig. 6 is a schematic representation in front view of the device of Fig. 1 in the release position.

[0020] Fig. 7 is a schematic side view representation of an image acquisition device provided with a motor according to an embodiment of the first aspect of the invention.

[0021] Fig. 8 is a schematic representation in front view of the device of Fig. 1 in filtering position whose polarization axis of the polarizing filter is in a first orientation.

[0022] Fig. 9 is a schematic representation in front view of the device of Fig. 1 in filtering position whose polarization axis of the polarizing filter is in a second orientation.

[0023] Fig. 10 is a schematic perspective cutaway representation of an image acquisition device comprising a casing according to certain embodiments.

[0024] Fig. 11 is a schematic perspective representation of a system according to the second aspect of the invention. Detailed description of the embodiments

[0025] Referring to Figs. 1 to 6, in a first aspect of the invention, there is provided an image acquisition device 1000 comprising: - a photosensitive sensor support 1001 provided with a motorized rotary axis 1002 oriented substantially perpendicular to the surface 1001a of said support 1001; - a photosensitive sensor 1003 fixed on said support 1001 in a manner substantially parallel to the surface 1001a of said support 1001; - a polarizing filter 1004 fixed on the motorized rotary axis and of a size adapted to cover the active surface 1003a of the photosensitive sensor 1003; - said motorized rotary axis 1002 is configured to pivot the polarizing filter 1004 into a so-called filtering position PF so as to cover the active surface 1003a of the photosensitive sensor 1003 by said polarizing filter 1004 and into a so-called release position PL so as to uncover the active surface 1003a of the photosensitive sensor 1003 when it is covered by said polarizing filter 1004.

[0026] In the context of the invention, a photosensitive sensor 1003 is understood to mean a photosensitive electronic component capable of converting electromagnetic radiation, in particular ultraviolet, visible or infrared electromagnetic radiation, into an electrical signal, then processing it to form an image. Such an electronic component is generally devoid of any optical element, such as a lens, capable of forming an optical system whose main function is to modify the trajectory of the electromagnetic radiation before it is captured by the active surface of said component.

[0027] A photosensitive sensor 1003 is usually a substantially planar sensor. Examples of photosensitive sensors are semiconductor sensors, such as charge-coupled devices, also called "CCD - Charge-Coupled-Device" in English, or CMOS type transistor sensors, "complementary metal-oxide-sem iconductor" in English.

[0028] A photosensitive sensor 1003 generally comprises an active surface 1003a from which electromagnetic radiation is collected. The size of the active surface 1003a varies depending on the type of sensor. It may consist of the entire surface of the sensor 1003 or only a portion thereof.

[0029] In the context of the invention, a polarizing filter is understood to mean a polarizing filter, also called a polarizer, as commonly defined in the field of wave optics, namely a film or a plate capable of selecting a preferential direction of polarization in an incident electromagnetic wave. A polarizing filter can polarize in a given range of wavelengths.

[0030] The polarizing filter 1004 can be fixed to the motorized rotating axis 1002 by any suitable means such as gluing, screwing, clipping or crimping. Preferably, it is mounted using a removable fastener to facilitate its replacement. For example, as illustrated in Figs. 1 to 6, the polarizing filter 1004 can be fixed to the motorized rotating axis 1002 by means of one or more screws 1006a, 1006b. For this purpose, with reference to Figs. 3 and 5, the motorized rotary axis 1002 can advantageously be provided with a plate 3001 for fixing the polarizing filter 1004. The plate 3001 can comprise a plate 3001a on which the filter 14 is fixed by means, for example, of two screws 1006a, 1006b, and a tube 3001b into which the rod 1002a of the motorized rotary axis 1002 is inserted. The tube 3001b is integral with the plate 3001 and located on the side opposite the surface on which the filter 1004 is fixed.

[0031] With reference to Figs. 4 to 6, the motorized rotary axis 1002 is configured to pivot the polarizing filter 1004 into a so-called filtering position PF so as to cover the active surface 1003a of the photosensitive sensor 1003 by said polarizing filter 1004, and into a so-called release position PL so as to uncover the active surface 1003a of the photosensitive sensor 1003 when it is covered by said polarizing filter 1004. For this purpose, the motorized rotary axis 1002, by rotating around its axis of rotation (A), moves the polarizing filter 1004 around this same axis (A) so as to place it either in the release position PL or in the filtering position PF.

[0032] With reference to Figs. 4 and 5, a so-called filtering position PF, the motorized rotary axis pivots, by rotation around its axis (A), the polarizing filter 1004 so as to cover the active surface 1003a of the photosensitive sensor 1003 by said polarizing filter 1004. In the figures, the filtering position PF is illustrated by the superposition of the polarizing filter 1004 on the active surface 1003a of the photosensitive sensor 1003 in a plane substantially parallel to that of said surface active 1003a. The active surface 1003a of the photosensitive sensor 1003 is located at a distance, d, from the lower surface 1004b of the polarizing filter 1004. Preferably, this distance is non-zero, the lower surface 1004b of the polarizing filter 1004 not being in contact with the active surface 1003a of the photosensitive sensor 1003 in order to avoid any risk of degradation of the active surface 1003a by the friction of the filter 1004 during its movement.

[0033] Unlike the device described in FR 3 109462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021, in the device according to the first aspect of the invention, as illustrated in Figs. 4 & 5, in the filtering position, no optical element, such as a lens, is arranged between the active surface 1003a of the photosensitive sensor 1003 and the polarization filter 1002. The polarizing filter 1004 is as close as possible to the active surface 1003a of the photosensitive sensor 1003. This arrangement makes it possible to advantageously reduce the distance, d, between the active surface 1003a of the photosensitive sensor 1003 and the lower surface 1004b of the polarizing filter 1004, and thus contribute to reducing the geometric size of the device 1000.

[0034] In the embodiment shown in Figs. 1 to 6, the active surface 1003a of the photosensitive sensor 1003 constitutes only a portion of the total surface of the sensor 1003. In Figs. 4 & 5, the size of the polarizing filter 1004 is adapted to cover only the active surface 1003a (not shown) of the photosensitive sensor 1003; this is the reason why it does not cover the entire surface of the sensor 1003. In the embodiments where the active surface 1003a of the photosensitive sensor 1003 constitutes a larger surface or the entire surface of said sensor 1003, the size of the filter 1004 is modified so as to cover the entire active surface 1003a; in this case, it may be larger in width and / or length. Conversely, if the active surface 1003a of the photosensitive sensor 1003 is smaller, the dimensions of the polarizing filter 1004 will be smaller.

[0035] Referring to Fig. 6, in the release position PL, the motorized rotary axis pivots, by rotation around its axis (A), the polarizing filter 1004 so as to uncover the active surface 1003a of the photosensitive sensor 1003 when it is covered by said polarizing filter 1004. The release position PL is here illustrated by the placement of the polarizing filter 1004 in an adjacent position above the photosensitive sensor 1003 in the plant of said sensor 1003. Equivalently, it could be placed below or on one of the sides.

[0036] The support 1001 of the photosensitive sensor 1003 is of any suitable type. It can be made of metal, organic resin or even thermoplastic polymer. It is preferably in the form of a plate. According to certain preferred embodiments, with reference to the figures, the support 1001 is an electronic card on which the photosensitive sensor 1003 is assembled. The electronic card, preferably of the microcontroller type, is configured to collect and process, using appropriate connectors, the signals from the photosensitive sensor 1003. The card can comprise an electronic connector 1005, such as a pin connector, of the PCI, SATA or IDE bus type, for communication with external electronic and / or electromechanical elements, such as, for example, a motor for animating the motorized rotary axis 1002.

[0037] The motorized rotary axis 1002 is arranged so as to cover or uncover the photosensitive sensor 1003 using the polarizing filter 1004 when it rotates on itself. Preferably, it is adjacent to the photosensitive sensor 1003 so that it can be as close as possible to the photosensitive sensor 1003 and its active surface 1003a, and further reduce the size of the device 1000. If, as illustrated in Figs. 3 & 5, the rotary axis 1002 is provided with a plate 3001 for fixing the polarizing filter 1004, the position of the rotary axis 1002 will have to be adjusted, in this case it could be moved away from the photosensitive sensor 1003, so that the plate 3001 does not obstruct the collection field of the active surface 1003a of the photosensitive sensor 1003.

[0038] The motorization of the rotary axis 1002 can be provided by any electric motor adapted in dimensions and power to precisely pivot a polarizing filter 1004 so as to cover a photosensitive sensor 1003. The motor is preferably an electric servomotor capable of continuously maintaining the polarizing filter 1004 in the filtering position (PF) or in the release position (PL).

[0039] Compared to the 1002 rotary axis, the electric motor can be arranged in any suitable way to optimize the space requirement. It can be offset to using a gear system with parallel and / or non-parallel axes or arranged in the axis (A) of rotation of the rotary axis 1002.

[0040] Referring to Fig. 7, according to preferred embodiments, the rotary axis 2002 is motorized using a motor 7000 located behind the support 1001 of the photosensitive sensor 1003 on the side opposite the photosensitive sensor 1003 and aligned along the axis (A) of rotation of the rotary axis 1002. In this configuration, the axis of rotation of the motor 7000 coincides with the axis (A) of rotation of the rotary axis 1002. For this purpose, by way of example, the motor 7000 may comprise an electric servomotor 7001, a fixing horn 7002 arranged and centered on the axis of rotation of the servomotor 7001 and an adapter 7003 ensuring a fixed mechanical connection between the rotary axis 1002, for example via the rod 1002a, and the fixing horn 7002.

[0041] As previously recalled, a polarizing filter 1004 is an optical element capable of selecting a preferential direction of polarization in an incident electromagnetic wave. This preferential direction is called the polarization axis. Also, the polarization direction of the electromagnetic radiation passing through the polarizing filter 1004 before being collected by the active surface 1003a of the photosensitive sensor 1003 varies according to the orientation of the polarization axis of said filter 1004 in a plane parallel to the active surface 1003a of the photosensitive sensor 1003, and consequently substantially perpendicular to the axis (A) of rotation of the rotary axis 1002.

[0042] According to some embodiments, with reference to Fig. 8 & 9, the motorized rotary axis 2002 is further configured to pivot the polarizing filter 1004 according to different orientations of the polarization axis (AP) of said polarizing filter 1004 when said polarizing filter 1004 is in the filtering position (PF).

[0043] As an illustrative example, by posing a polar coordinate system in the plane of the polarizing filter 1004 having as origin, O, the point of intersection of said plane with the axis (A) of rotation of the rotary axis 1002, the direction of polarization (DP) of the radiation passing through the polarizing filter 1004 can be represented by an angle θ of polarization between said direction of polarization (DP) of said polarizing filter 1004 and a reference axis (AR) perpendicular to the axis (A) of rotation of the rotary axis 1002 and to a normal to the active surface. 1003a of the photosensitive sensor 1003. In Figs. 8 & 9, the reference axis (AR) is chosen in a plane of symmetry of the active surface 1003 of the photosensitive sensor 1003. In Fig. 8, the angle 9 is set at 17° relative to the reference axis (AR) in the anti-trigonometric direction. In Fig. 9, it is set at 10° in the trigonometric direction.

[0044] According to certain preferred embodiments, illustrated in Figs. 1 to 9, the polarizing filter 1004 has the shape of a lunula or a circular sector. This type of shape is advantageous for keeping a polarizing filter 1004 of reduced size while facilitating the complete coverage of the active surface 1003a of the photosensitive sensor 1003 by the polarizing filter 1004 and allowing the arrangement of the polarizing filter 1004 according to different orientations of its polarization axis (DP).

[0045] In all of the embodiments described above and illustrated in Fig. 1 to 9, the device 1000 comprises only one polarizing filter 1004 fixed on the motorized rotary axis 1004. However, this is in no way limiting. An advantage of the device 1000 according to the first aspect of the invention is that the motorized rotary axis 1002 can be the support for other optical elements, such as an infrared filter or a neutral density filter, the size of which, substantially similar to that of the polarizing filter 1004, can be considerably reduced compared to the prior art. In addition, a single motorized rotary axis and a single motor can be used to drive the rotation of the optical elements and their successive positioning.

[0046] Thus, according to certain embodiments, the device further comprises an infrared filter (not shown) fixed on the motorized rotary axis 1002 and of a size adapted to cover the active surface 1003a of the photosensitive sensor 1003, and the motorized rotary axis 1002 is configured to pivot the infrared filter so as to cover the active surface 1003a of the photosensitive sensor 1003 by said infrared filter when the polarizing filter 1004 is not in the filtering position. The use of an infrared filter can be advantageous for the acquisition of images in night conditions or in very low light.

[0047] In the filtering position (PF), the polarizing filter 1004 covers the surface 1003a of the photosensitive sensor 1003. Depending on the nature of the polarizing filter 1004, this arrangement can cause a modification of the optical path of the electromagnetic radiation to which the photosensitive sensor 1003 can be more or less sensitive depending on its type. Unlike the prior art, in particular unlike the device described in FR 3 109462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021, this possible modification of the optical path is not compensated by the presence of an optical system between the polarizing filter 1004 and the photosensitive sensor 1003. If the photosensitive sensor 1003 can possibly be calibrated so as to compensate for this modification of the optical path when the polarizing filter 1004 is in the filtering position (PF), when the latter is in the release position, this compensation, if it persists, can become troublesome for obtaining a quality image. The use of an infrared filter as described in the preceding embodiments can be affected by the same drawback.

[0048] Also, according to certain embodiments, the device further comprises an optical path compensating blade (not shown) mounted on the motorized rotary axis 1002 and of a size adapted to cover the active surface 1003a of the photosensitive sensor 1003, and the motorized rotary axis 1002 is configured to pivot the compensating blade so as to cover the active surface 1003a of the photosensitive sensor 1003 by said compensating blade when the polarizing filter 1004 is not in the filtering position (PF).

[0049] An advantage of the device 1000 according to the first aspect of the invention is its compactness. Its small spatial footprint makes it possible to reduce the size of the protective boxes of the road control machines, and in particular the size of a protective box or casing in which the device would be placed.

[0050] Thus, according to certain embodiments, with reference to Fig. 10, the device comprises a casing 10001 in which said image acquisition device 1000 is arranged, the casing 10001 comprising a clearance space 10002 arranged at the periphery of the photosensitive sensor 1003 and the dimensions of which are adapted to receive the polarizing filter 1004 when it is in the release position (PL). When the device 1000 comprises other optical elements than the polarizing filter 1004 in accordance with the embodiments described above, the dimensions of the clearance space 10002 clearance may be adapted accordingly although, since these additional optical elements are of a size substantially similar to that of the polarizing filter, such adaptation is not always necessary.

[0051] The formwork 10001 may be fixed to the device 1000 by any suitable fixing means. For example, the support 1001 of the photosensitive sensor 1003 may be provided with through holes arranged so as to coincide with threaded blind holes provided in the walls of the formwork 10001, and with screws capable of being housed in the threaded blind holes after their shanks have passed through the through holes of the support 1001.

[0052] According to certain embodiments, with reference to Fig. 10, the formwork further comprises an opening 10003, preferably provided with a thread 10003a, capable of receiving an optical objective (not shown) and whose central axis (AC) coincides with the optical axis (AO) of the active surface 1003a of the photosensitive sensor 10003.

[0053] According to a second aspect of the invention, with reference to Fig. 11, there is provided a system 11000 comprising: - an image acquisition device 1000 according to any one of the embodiments of the first aspect of the invention; - an optical objective 11001 arranged in front of the image acquisition device 1000 and whose optical axis (AO1) coincides with the optical axis (AO) of the active surface 1003a of the photosensitive sensor 1003 of said acquisition device 1000.

[0054] In the context of the present invention, an optical objective is understood to mean a system whose main function is to modify the trajectory of electromagnetic radiation. In particular, an optical objective is understood to mean an optical device formed from a succession of spherical, aspherical or planar diopters, such as optical lenses, and capable of forming the image of an object located at certain depths of field. A photographic objective is an example of an optical objective that can be used in the context of the invention.

[0055] As illustrated in Fig. 11, when the optical lens 11001 is arranged in accordance with the second aspect of the invention and the polarizing filter 1004 is in the filtering position (PF), the polarizing filter 1004 is arranged between the optical objective 10001 and the active surface 1003a of the photosensitive sensor 10003.

[0056] When the image acquisition device 1000 comprises a casing 10001 in accordance with certain embodiments of the first aspect of the invention, the optical objective 110001 can advantageously be mounted on an opening 1003 of said casing 1000a provided for this purpose.

[0057] An image acquisition device 1000 in accordance with the first aspect of the invention and / or a system in accordance with the second aspect of the invention may be advantageously used in a road control machine. References Patent literature

[0058] EP 2 690 459 A2, JENOPTIK ROBOT GMBH [DE], 29.01.2014.

[0059] EP 3 012 652 A1, MORPHO [FR], 27.04.2016.

[0060] FR 3 109 462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021.

Claims

Claims

1. Image acquisition device (1000) comprising: - a photosensitive sensor support (1001) provided with a motorized rotary axis (1002) oriented substantially perpendicular to the surface (1001a) of said support (1001); - a photosensitive sensor (1003) fixed on said support (1001) in a manner substantially parallel to the surface (1001a) of said support (1001); - a polarizing filter (1004) fixed on the motorized rotary axis and of a size adapted to cover the active surface (1003a) of the photosensitive sensor (1003); - said motorized rotary axis (1002) is configured to pivot the polarizing filter (1004) into a so-called filtering position (PF) so as to cover the active surface (1003a) of the photosensitive sensor (1003) with said polarizing filter (1004) and into a so-called release position (PL) so as to uncover the active surface (1003a) of the photosensitive sensor (1003) when it is covered by said polarizing filter (1004).

2. Device (1000) according to claim 1, such that the support (1001) is an electronic card on which the photosensitive sensor (1003) is assembled.

3. Device (1000) according to any one of claims 1 to 2, such that the rotary axis (1002) is motorized using a motor (7000) located behind the support (1001) of the photosensitive sensor (1003) on the side opposite the photosensitive sensor (1003) and aligned along the axis (A) of rotation of the rotary axis (1002).

4. Device (1000) according to any one of claims 1 to 3, such that the motorized rotary axis (1002) is adjacent to the photosensitive sensor (1003).

5. Device (1000) according to any one of claims 1 to 4, such that the motorized rotary axis (2002) is further configured to pivot the polarizing filter 1004 according to different orientations of the polarization axis (AP) of said polarizing filter (1004) when said polarizing filter (1004) is in the filtering position (PF).

6. Device (1000) according to any one of claims 1 to 5, such that the polarizing filter (1004) has substantially the shape of a lunula or a circular sector.

7. Device (1000) according to any one of claims 1 to 4, such that it further comprises an infrared filter (not shown) fixed on the motorized rotating axis (1002) and of a size adapted to cover the active surface (1003a) of the photosensitive sensor (1003), and the rotating axis is configured to pivot the infrared filter so as to cover the active surface (1003a) of the photosensitive sensor (1003) by said infrared filter when the polarizing filter (1004) is not in the filtering position.

8. Device (1000) according to any one of claims 1 to 5, such that it further comprises an optical path compensating blade fixed on the motorized rotating axis (1002) and of a size adapted to cover the active surface (1003a) of the photosensitive sensor (1003), and the motorized rotating axis (1002) is configured to pivot the compensating blade so as to cover the active surface (1003a) of the photosensitive sensor (1003) by said compensating blade when the polarizing filter (1004) is not in the filtering position (PF).

9. Device (1000) according to any one of claims 1 to 8, such that it comprises a casing (10001) in which said image acquisition device (1000) is arranged, the casing (10001) comprising a clearance space (10002) arranged at the periphery of the photosensitive sensor (1003) and the dimensions of which are adapted to receive the polarizing filter (1004) when it is in the release position (PL).

10. Device (1000) according to claim 9, such that the casing (10001) has an opening (10003), preferably provided with a thread (10003a), capable of receiving an optical objective (not shown) and whose central axis (AC) coincides with the optical axis (AO) of the active surface 1003a of the photosensitive sensor (10003).

11. System (11000) comprising: - an image acquisition device (1000) according to any one of claims 1 to 10; - an optical objective (11001) arranged in front of the image acquisition device (1000) and whose optical axis (AO1) coincides with the optical axis (AO) of the active surface (1003a) of the photosensitive sensor (1003) of said acquisition device (1000).

12. Use of an optical device according to any one of claims 1 to 10 or a system according to claim 11 in a road control machine.

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