Image acquisition device for automated traffic control systems

Abstract

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

Description

Title of the invention: Image acquisition device for automated traffic control systems Technical field

[0001] The present invention relates to an image acquisition device for automated road traffic control. Technical background

[0002] It is common practice to control or monitor road traffic using automated systems comprising speedometers—radar or laser devices for measuring the speed and position of vehicles—and optical systems configured for acquiring images of the interior and / or exterior of vehicles. These systems are programmed to detect and characterize certain traffic violations committed by vehicle drivers through the combined analysis of speedometer signals and acquired images. In particular, they allow for the generation of elements for classifying and proving the violation, and for extracting information from the images, such as license plate numbers, enabling the identification of the offender for issuing a traffic ticket.

[0003] The reliability of these automated systems relies in part on the acquisition of images of sufficient quality to identify the elements relevant to characterizing the offense. This identification must be unambiguous regardless of the lighting or weather conditions under which these images are acquired. Therefore, it is essential that the optical systems of automated traffic enforcement systems exhibit the best optical performance, day and night, in good weather or inclement conditions, to ensure perfect correlation between the data from the speed cameras and the images acquired by these systems for each vehicle checked.

[0004] EP 2 690 459 A2, JENOPTIK ROBOT GMBH [DE], 29.01.2014 describes a traffic control system comprising a radar or laser speed gun and two cameras, one of which is a high-resolution camera. The speed gun and the two cameras are arranged so that their respective optical fields overlap. The system 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 speed gun.

[0005] EP 3 012 652 A1, MORPHO [FR], 27.04.2016 describes a road traffic control unit comprising a speed camera and optical devices mechanically assembled together using a mounting plate. The mounting plate includes fasteners for holding the devices Optical positives in a specific angular orientation relative to a radio axis of the speedometer. This unit simplifies its installation and improves the accuracy of its adjustment to ensure a match between the vehicle monitored by the speedometer and the one appearing in the images acquired by the optical devices.

[0006] FR 3 109 462 Al, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021 describes a road surveillance system capable of acquiring high-quality images of the interior of a vehicle, day and night. This system comprises several photosensitive sensors. Each photosensitive sensor is equipped with an optical lens and a polarizing filter mounted in a removable and movable manner in front of said lens. The polarizing filter reduces, or even eliminates, glare on the photosensitive sensors caused by specular reflections of light on the reflective surfaces of vehicles. It is fixed to a motorized rotating axis configured to pivot alternately in a so-called filtering position, so as to cover the surface of the lens of the optical objectives, and in 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

[0007] Today, there is a need to reduce the spatial footprint of automated systems in order to make them not only more discreet but also to allow their deployment in road environments where the topographical characteristics present constraints in terms of positioning and free space. This is particularly true of urban and suburban road areas. Compact automated systems are also advantageous for facilitating their transport, maintenance, and handling.

[0008] However, a first drawback of the automaton described in FR 3 109 462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021 is the space occupied by the assembly formed by the optical lenses and polarizing filters. Clearance space must be provided around the ends of the optical lenses when the filters are in the release position, that is, when they are pivoted to expose their lenses. The size of the polarizing filters varies with that of the optical lenses, particularly with the size of their lenses. The larger the optical lenses, the larger the filters. The clearance space must therefore be correspondingly larger as the optical lenses are larger, and providing such space can quickly become a technical constraint that is difficult to reconcile with the other components of the automaton.This is particularly the case when the automaton is used to control a remote road or several roadways in spaces simultaneously where several high-resolution objectives are involved. Large sizes may be required.

[0009] A second drawback 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 automated system, 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 assembling the automated system or for maintenance operations, for example when changing filters, can become a logistical constraint for operators, particularly with regard to the availability of these parts. Technical solution

[0011] In a first aspect of the invention, an image acquisition device is described comprising: - a photosensitive sensor support equipped with a motorized rotating axis oriented substantially perpendicular to the surface of said support; - a photosensitive sensor fixed on said support in a manner substantially parallel to the surface of said support; - a polarizing filter fixed on the motorized rotating axis and of a size suitable to cover the active surface of the photosensitive sensor; - The motorized rotating axis is configured to pivot the polarizing filter into a so-called filtering position so as to cover the active surface of the photosensitive sensor with said polarizing filter, and into a so-called release (PL) position so as to uncover the active surface of the photosensitive sensor when it is covered by said polarizing filter. Advantageous embodiments are described below.

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

[0013] A third aspect of the invention describes the use of an optical system according to the second aspect of the invention in a traffic control system. 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 front view representation of the device of [Fig.1]

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

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

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

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

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

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

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

[0023] [Fig. 10] is a schematic cutaway perspective 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 implementation methods

[0025] With reference to [Fig. 1] to 6, in a first aspect of the invention, an image acquisition device 1000 is provided comprising: - a photosensitive sensor support 1001 equipped with a motorized rotating 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 rotating axis and of a size adapted to cover the active surface 1003a of the photosensitive sensor 1003; - said motorized rotating axis 1002 is configured to pivot the polarizing filter 1004 into a position called filtering PF so as to cover the active surface 1003a of the photosensitive sensor 1003 by said polarizing filter 1004 and into a position called release 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 be a photosensitive electronic component capable of converting electromagnetic radiation, in particular ultraviolet, visible, or infrared electromagnetic radiation, into an electrical signal, and then processing it to form an image. Such an electronic component is generally devoid of any optical elements, such as a lens, capable of forming an optical system whose main function is to modify the trajectory of electromagnetic radiation before its capture by the active surface of said component.

[0027] A photosensitive sensor 1003 is usually a substantially flat 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-semiconductor" in English.

[0028] A photosensitive sensor 1003 generally includes 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 plate capable of selecting a preferred direction of polarization in an incident electromagnetic wave. A polarizing filter can polarize within a given range of wavelengths.

[0030] The polarizing filter 1004 can be attached to the motorized rotating shaft 1002 by any suitable means such as gluing, screwing, clipping, or crimping. Preferably, it is mounted using a removable fastener to facilitate replacement. For example, as illustrated in [Fig. 1] to 6, the polarizing filter 1004 can be attached to the motorized rotating shaft 1002 by means of one or more screws 1006a, 1006b. For this purpose, with reference to [Fig. 3] and 5, the motorized rotating shaft 1002 can advantageously be equipped with a mounting plate 3001 for the polarizing filter 1004. The mounting 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 rotating shaft 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 [Fig. 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. To this end, the motorized rotary axis 1002, by rotating about its axis of rotation (A), moves the polarizing filter 1004 about 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 [Fig. 4] and 5, in a so-called PF filtering position, the motorized rotating shaft pivots, by rotation around its axis (A), the polarizing filter 1004 so as to cover The active surface 1003a of the photosensitive sensor 1003 is covered 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 active surface 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 3 109 462 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 polarizing filter 1002. The polarizing filter 1004 is as close as possible to the active surface 1003a of the photosensitive sensor 1003. This arrangement advantageously reduces 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 contributes to reducing the geometric size of the device 1000.

[0034] In the embodiment shown in [Figs. 1] to 6, the active area 1003a of the photosensitive sensor 1003 constitutes only a portion of the total area of ​​the sensor 1003. In [Figs. 4] and 5, the size of the polarizing filter 1004 is adapted to cover only the active area 1003a (not shown) of the photosensitive sensor 1003; this is why it does not cover the entire area of ​​the sensor 1003. In embodiments where the active area 1003a of the photosensitive sensor 1003 constitutes a larger area or the entire area of ​​said sensor 1003, the size of the filter 1004 is modified so as to cover the entire active area 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] With reference to [Fig. 6], in the release position PL, the motorized rotating shaft pivots, by rotation about its axis (A), the polarizing filter 1004 so as to expose the active surface 1003a of the photosensitive sensor 1003 when it is covered by said polarizing filter 1004. The release position PL is illustrated here by placing the polarizing filter 1004 in a position adjacent to above the photosensitive sensor 1003 in the plane of said sensor 1003. Equivalently, it could be placed below or on one of the sides.

[0036] The support 1001 for the photosensitive sensor 1003 is of any suitable type. It can be made of metal, organic resin, or thermoplastic polymer. It is of preferably in the form of a plate. According to some preferred embodiments, with reference to the figures, the support 1001 is an electronic board on which the photosensitive sensor 1003 is mounted. The electronic board, preferably of the microcontroller type, is configured to collect and process, using appropriate connectors, the signals from the photosensitive sensor 1003. The board may include 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 rotating shaft 1002 is arranged to cover or uncover the photosensitive sensor 1003 with the polarizing filter 1004 as it rotates. 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 overall size of the device 1000. If, as illustrated in [Figs. 3] & 5, the rotating shaft 1002 is equipped with a mounting plate 3001 for the polarizing filter 1004, the position of the rotating shaft 1002 must be adjusted; in this case, it can be moved further away from the photosensitive sensor 1003 so that the mounting plate 3001 does not obstruct the collection field of the active surface 1003a of the photosensitive sensor 1003.

[0038] The motorization of the rotating axis 1002 can be ensured 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] Relative to the rotating axis 1002, the electric motor can be arranged in any suitable manner to optimize the overall dimensions. It can be offset by means of a system of gears with parallel and / or non-parallel axes or arranged in the axis (A) of rotation of the rotating axis 1002.

[0040] With reference to [Fig. 7], according to preferred embodiments, the rotating shaft 2002 is driven by a motor 7000 located behind the photosensitive sensor 1001 support on the opposite side of the photosensitive sensor 1003 and aligned with the axis (A) of rotation of the rotating shaft 1002. In this configuration, the axis of rotation of the motor 7000 coincides with the axis (A) of rotation of the rotating shaft 1002. For this purpose, by way of example, the motor 7000 may comprise an electric servomotor 7001, a mounting bracket 7002 positioned and centered on the axis of rotation of the servomotor 7001, and an adapter 7003 providing a mechanical connection between the rotating shaft 1002, for example via the rod 1002a, and the bracket 7002. fastening.

[0041] As previously mentioned, a polarizing filter 1004 is an optical element capable of selecting a preferred polarization direction in an electric wave incident tromagnetic. This preferred 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 rotating axis 1002.

[0042] According to certain embodiments, with reference to [Fig.8] & 9, the motorized rotating 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] By way of illustration, by establishing a polar coordinate system in the plane of the polarizing filter 1004 with its origin, O, the point of intersection of said plane with the axis (A) of rotation of the rotating axis 1002, the polarization direction (DP) of the radiation passing through the polarizing filter 1004 can be represented by a polarization angle θ between said polarization direction (DP) of said polarizing filter 1004 and a reference axis (AR) perpendicular to the axis (A) of rotation of the rotating axis 1002 and to a normal to the active surface 1003a of the photosensitive sensor 1003. In [Fig. 8] & [Fig. 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 θ is fixed at 17° with respect to the reference axis (AR) in the anti-trigonometric direction. In [Fig.9], it is fixed at 10° in the trigonometric direction.

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

[0045] In all the embodiments described above and illustrated in [Fig. 1] to 9, the device 1000 comprises only a single polarizing filter 1004 fixed to the motorized rotating shaft 1004. However, this is not in any way limiting. An advantage of the device 1000 according to the first aspect of the invention is that the motorized rotating shaft 1002 can support 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. Furthermore, a single motorized rotating shaft 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 rotating axis 1002 and of a size adapted to The motorized rotating axis 1002 is configured to pivot the infrared filter so that it covers the active surface 1003a of the photosensitive sensor 1003 when the polarizing filter 1004 is not in the filtering position. The use of an infrared filter can be advantageous for acquiring images in nighttime or very low-light conditions.

[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 may be more or less sensitive depending on its type. Unlike the prior art, and in particular unlike the device described in FR 3 109 462 A1, IDEMIA IDENTITY & SECURITY FRANCE [FR], 22.10.2021, this potential modification of the optical path is not compensated for by the presence of an optical system between the polarizing filter 1004 and the photosensitive sensor 1003.While the photosensitive sensor 1003 can potentially be calibrated to compensate for this change in the optical path when the polarizing filter 1004 is in the filtering (PF) position, when it is in the release position, this compensation, if persistent, can become problematic for obtaining high-quality images. The use of an infrared filter as described in previous embodiments can be affected by the same drawback.

[0048] Also, according to some embodiments, the device further includes an optical path compensating blade (not shown) mounted on the motorized rotating axis 1002 and of a size adapted to cover the active area 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 area 1003a of the photosensitive sensor 1003 by said compensating blade when the polarizing filter 1004 is not in the filtering position (PF).

[0049] One advantage of the device 1000 according to the first aspect of the invention is its compactness. Its small size makes it possible to reduce the size of the protective housings for automated traffic control systems, and in particular the size of a protective enclosure or casing in which the device would be placed.

[0050] Thus, according to certain embodiments, with reference to [Fig. 10], the device comprises a housing 10001 in which said image acquisition device 1000 is disposed, the housing 10001 comprising a clearance space 10002 arranged at the periphery of the photosensitive sensor 1003 and whose dimensions 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 10002 clearance space can be adapted accordingly, although, as these additional optical elements are of a size substantially similar to that of the polarizing filter, such adaptation is not always necessary.

[0051] The casing 10001 can be fixed to the device 1000 by any suitable fastening means. For example, the support 1001 of the photosensitive sensor 1003 can be provided with through holes arranged so as to coincide with threaded blind holes provided in the walls of the casing 10001, and with screws adapted to fit into 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 casing further includes an opening 10003, preferably equipped with a thread 10003a, suitable for receiving an optical lens (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], a system 11000 is provided comprising: - a 1000 image acquisition device according to any one of the embodiments of the first aspect of the invention; - an optical lens 11001 disposed 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 be a system whose principal function is to modify the path of electromagnetic radiation. In particular, an optical objective is understood to be an optical device formed by a succession of spherical, aspherical, or plane diopters, such as optical lenses, and capable of forming the image of an object located at certain depths of field. A photographic lens is an example of an optical objective that can be used in the context of the invention.

[0055] As illustrated in [Fig.1 1], 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 lens 10001 and the active surface 1003a of the photosensitive sensor 10003.

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

[0057] A 1000 image acquisition device according to the first aspect of the invention and / or a system according to the second aspect of the invention can be advantageously used in a road traffic control automation system. References Patent literature

[0058] EP 2 690 459 A2, JENOPTIK ROBOT GMBH [DE], 01.29.2014.

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

[0060] FR 3 109 462 Al, 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) 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 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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