Optical system comprising at least a first laser emitter and a second laser emitter

Abstract

The invention relates to an optical projection system (1), in particular for a motor vehicle (10), comprising a first laser emitter (31) configured to emit a primary light beam (Fx1) and a second laser emitter (32) configured to emit a secondary light beam (Fx2) towards an oscillating mirror device (4) and respectively towards a first portion (Px1) and a second portion (Px2) of a projection surface (2).

Description

Optical system comprising at least one first laser emitter and one second laser emitter.

[0001] The invention relates to an optical system, for example for a motor vehicle, comprising a first laser emitter and a second laser emitter configured to each emit, simultaneously or not, a light beam onto an oscillating mirror device. The invention also relates to a method of operating such an optical system.

[0002] In the automotive industry, it is common practice to equip vehicles with various optical systems. These systems can be integrated into a headlight, particularly a front headlight, a rocker panel, or a rearview mirror, to provide lighting and / or project specific information onto a defined projection surface on the road ahead. Similarly, such optical systems can be incorporated into interior display systems, such as head-up displays, or display systems designed to project information onto a dashboard or a pillar adjacent to the windshield.

[0003] Such optical systems typically use a laser emitter comprising one or more laser light sources to emit a directional beam of light, which is more efficient than LED light sources. However, the high brightness of laser light sources makes them susceptible to damaging an observer's eye if viewed directly, thus rendering them dangerous if used improperly or unsafely.

[0004] This drawback results in the integration of laser light sources, particularly in the automotive sector, being regulated and limited. For example, the power of laser light sources integrated into vehicle headlights, used for vehicle illumination and / or visibility, or in interior or exterior vehicle information display systems, is significantly limited. Consequently, the level of contrast and detail achievable with such laser light sources is limited, making them poorly suited for projecting information onto projection surfaces, especially in bright daylight.

[0005] The invention falls within this context and aims to offer an alternative to known optical systems enabling the secure integration of laser light sources, particularly for integration into a motor vehicle.

[0006] To this end, the invention relates to an optical projection system comprising at least a first laser emitter, a second laser emitter and an oscillating mirror device: - the first laser emitter being configured to emit a primary light beam and the second laser emitter being configured to emit a secondary light beam, capable of forming respectively a primary light spot and a secondary light spot on the oscillating mirror device, the first laser emitter and the second laser emitter being configured so that the primary light beam and the secondary light beam reach the oscillating mirror device at different angles and so that an incident separation angle separating said beams upstream of the oscillating mirror device, and / or an outgoing separation angle separating said beams downstream of the oscillating mirror device has a non-zero value;- the oscillating mirror device being configured to reflect the primary light beam and the secondary light beam respectively towards a first portion and a second portion included in a projection surface and at least partly distinct from each other.;

[0007] Optionally, the optical projection system further includes a control unit configured to control at least the switching on and off of the first laser emitter and the second laser emitter as a function of the movement of the oscillating mirror device and / or configured to control an intensity of the primary light beam and the secondary light beam as a function of the movement of the oscillating mirror device.

[0008] In particular, the incident separation angle and / or the outgoing separation angle separating the primary light beam and the secondary light beam has a value strictly greater than 4.00°.

[0009] In particular, the oscillating mirror device is defined by at least one oscillation amplitude, corresponding to an amplitude of displacement of said mirror between two opposite extreme positions along at least one direction, the incident separation angle and / or the exit separation angle being equal to, or substantially equal to, an angle of the oscillation amplitude of the oscillating mirror device corresponding to an amplitude of displacement of said mirror between two opposite extreme positions along at least one direction.

[0010] Alternatively: - the incident separation angle and / or the exit separation angle is strictly greater than an angle of the oscillation amplitude of the oscillating mirror device so that the primary light beam and the secondary light beam are projected onto adjacent portions of the projection surface separated by a non-zero gap; or - the incident separation angle and / or the exit separation angle is strictly less than an angle of the oscillation amplitude of the oscillating mirror device so that the primary light beam and the secondary light beam are projected onto portions of the projection surface that are at least partially superimposed.

[0011] Optionally, the optical projection system further includes a control unit for the first laser emitter and the second laser emitter configured to vary the intensity of the first laser emitter and / or the second laser emitter as a function of the position of the oscillating mirror device and / or as a function of the position of the primary light beam and the secondary light beam in the projection surface so as to ensure homogeneity of illumination within said projection surface.

[0012] Optionally: - the first laser emitter includes a plurality of RGB type laser light sources combining red(s), green(s) and blue(s) laser light sources to project the combined primary light beam onto the oscillating mirror device; and / or - the second laser emitter includes a plurality of RGB type laser light sources combining red(s), green(s) and blue(s) laser light sources to project the combined secondary light beam onto the oscillating mirror device.

[0013] According to one embodiment, the optical projection system further includes an optical device comprising at least one first optical assembly, disposed downstream of the oscillating mirror device in a direction of propagation of the primary light beam and / or the secondary light beam.

[0014] Alternatively, the optical projection system comprises an optical device having a first optical set, a second optical set and a translucent screen, interposed between the first optical set and the second optical set: - the translucent screen having an entrance face turned towards the first optical set and an exit face, opposite to the entrance face, and turned towards the second optical set; - an image focus of the first optical set being disposed on the exit face of the translucent screen, so that the first optical set is configured to form a first intermediate image of the primary light spot and a second intermediate image of the secondary light spot on the exit face of the translucent screen; and - the second optical set being configured to project onto a projection surface an image of said intermediate images.

[0015] In particular, the oscillating mirror device comprises a movable scanning mirror and a mechanical drive means: - the oscillating mirror device being configured to implement a "raster" type scan, the mechanical means being capable of making the scanning mirror oscillate along a first axis and a second axis, extending perpendicularly to each other, an oscillation speed of the oscillating mirror device along the first axis being higher than an oscillation speed of said device along the second axis; or - the oscillating mirror device being configured to implement a "Lissajous" type scan, the mechanical means being capable of making the oscillating mirror device oscillate along two orthogonal axes, according to a monotonic sinusoidal waveform with constant amplitude in each axis.

[0016] The invention can also be extended to a vehicle comprising an optical projection system according to the invention.

[0017] The invention can be extended to a method of projecting a light beam onto a projection surface by means of an optical system according to the invention, comprising the projection of at least one primary light beam, emitted by the first laser emitter, and at least one secondary light beam, emitted by the second laser emitter, towards the oscillating mirror device so that these are respectively reflected towards the first portion and the second portion of the projection surface, at least partly distinct, in particular at the same given instant.

[0018] The invention also relates to a vehicle comprising an optical projection system according to the invention.

[0019] Further details, features and advantages will become clearer upon reading the detailed description given below, which is indicative and not exhaustive, in relation to the various implementation examples illustrated in the following figures:

[0020] This is a general schematic representation of an optical system comprising a first laser emitter and a second laser emitter spatially separated and fitted in a vehicle.

[0021] This is a schematic representation of an example of variation of the optical system according to the.

[0022] This is a schematic representation of a scan performed by an oscillating "raster" type mirror device on a projection surface comprising a first portion and a second portion glued together.

[0023] This is a schematic representation from the point of view of an observer when a "raster" scan is performed.

[0024] Laest is a schematic representation of the "raster" type scanning on a projection surface comprising a first portion and a second portion separated from each other.

[0025] This is a schematic representation of an example of an implementation of the optical system including an optical device comprising a translucent screen.

[0026] Figures 1 to 6 schematically illustrate examples of embodiments of an optical system 1 according to the invention configured to project at least one beam of light onto a projection surface 2. In particular, according to one embodiment shown in Figure 6, which is not limiting, the optical system 1 is integrated into a motor vehicle 10. In another particular embodiment, the optical system 1 is integrated into a headlight of the vehicle, in particular a front headlight, so as to provide lighting and / or project specific information onto a projection surface 2 defined on the road surface. Here, "projection surface" means a surface onto which the optical system 1 is capable of projecting information for the attention of a user.

[0027] In alternative embodiments, the optical system 1 is integrated into a rearview mirror, or side mirror, of the vehicle 10 or into a lower body panel of the vehicle 10, so as to provide lighting and / or project specific information onto a portion of the roadway. In further alternative embodiments, the optical system 1 is integrated into an information display system located in the passenger compartment of the vehicle 10, such as a head-up display system or a display system projecting information onto a projection surface within a support framed by the windshield of the vehicle 10, a projection screen, the windshield itself, or onto the dashboard of the passenger compartment.

[0028] By convention in the description below, the direction in which the motor vehicle 10 moves in a straight line is defined as the longitudinal direction X, the axis representing the longitudinal direction X being oriented, conventionally, from front to back. The direction perpendicular to the longitudinal direction and located in a plane parallel to the ground is called the transverse direction Y. The direction perpendicular to the X and Y directions, orthogonal to the ground on which the vehicle rests, is called the vertical direction Z. A direct XYZ coordinate system is thus defined, as shown in the figures where required. The terms "first" and "second" or "primary" and "secondary" are intended to distinguish similar elements and not to define a hierarchy among them. Similarly, the terms "upstream" and "downstream" refer to the direction of propagation of at least one light beam Fx under consideration.

[0029] It is understood that the invention applies mutatis mutandis to an optical system 1 according to the invention implemented in a context other than that of a motor vehicle.

[0030] In the illustrated example, the projection surface 2 is located, but not limited to, in front of the vehicle 10. Specifically, the projection surface 2 is inclined relative to the optical system 1, i.e., relative to the projector or the rearview mirror, such that the distances between a point on the optical system 1 and different points on the projection surface 2 at ground level on which the vehicle 10 rests are not equal. In particular, the optical system 1 is configured to project at least one grazing beam of light Fx onto the projection surface 2.

[0031] The projection surface 2 under consideration may be more or less extensive. For example, in the illustrated example, the projection surface 2 extends over all or part of a possible projection area whose proximal limit Lp is, for example, located 15 cm, or even 30 cm, from the optical system 1 or the front of the vehicle 10 along a defined projection direction, and whose distal limit Ld is located 1.5 m, or even 3 m, from the optical system 1, the projection surface 2 being contained between the proximal limit Lp and the distal limit Ld. The proximal limit Lp thus corresponds to the limit of the projection surface 2 closest to the optical system 1 or the front of the vehicle 10, while the distal limit Ld is the most distant limit. In this case, the projection direction 500 extends parallel, or substantially parallel, to the longitudinal direction X.The projection surface 2 is, according to a non-limiting preferred embodiment example, rectangular or substantially rectangular and is defined along a first direction 100, parallel to the projection direction 500, between the proximal limit Lp and the distal limit Ld, and along a second direction 200, perpendicular to the first direction 100, between at least one first extreme edge B1 and a second extreme edge B2, opposite each other.

[0032] In general, the optical system 1 according to the invention comprises a plurality of laser emitters, particularly at least a first laser emitter 31 and a second laser emitter 32, an oscillating mirror device 4 and, optionally, a control unit 42 configured to control at least the switching on and off of the first laser emitter 31 and the second laser emitter 32 as a function of the displacement of the oscillating mirror device 4 and / or configured to control an intensity of the primary light beam Fx1 and the secondary light beam Fx2 as a function of the sweep of the oscillating mirror device 4. Optionally, as further described below, the optical system 1 further comprises an optical device 5.Note that the invention may include more laser emitters having the characteristics defined below with reference to the first laser emitter and the second laser emitter, the description below applying mutatis mutandis to more laser emitters.

[0033] The first laser emitter 31 is configured to emit at least one primary light beam Fx1 towards the oscillating mirror device 4. Optionally, but preferably, the first laser emitter 31 comprises a plurality of laser light sources 31x. These sources may be monochrome or not. For example, they may include red, green, and / or blue laser light sources. If the first laser emitter 31 comprises at least one red laser light source, one green laser light source, and one blue laser light source, then the first laser emitter 31 is an "RGB laser emitter," capable of emitting a primary light beam Fx1 of the desired color. Each laser light source in the first laser emitter 31 emits its own primary light sub-beam Fx1', and these are combined to form the primary light beam Fx1.In a known, not detailed but illustrated manner, the use of a plurality of distinct colour laser light sources is optionally accompanied by the use of at least one dichroic mirror 33. The primary light beam Fx1, in particular each of the primary light subbeams Fx1', is then directed towards a reflective surface of the oscillating mirror device 4 at which it forms a primary light spot Tx1.

[0034] Optionally, alternatively, or additionally, a similar principle applies to the second laser emitter 32. The second laser emitter 32 is configured to emit at least one secondary light beam Fx2 towards the oscillating mirror device 4. Optionally, but preferably, the second laser emitter 32 comprises a plurality of laser light sources 32x. These sources may be monochrome or not. For example, these sources may include red, green, and / or blue laser light sources. If the second laser emitter 32 comprises at least one red laser light source, one green laser light source, and one blue laser light source, then the second laser emitter 32 is an "RGB laser emitter," enabling the emission of a secondary light beam Fx2 of the desired color.Each laser light source of the second laser emitter 32 then emits its own secondary light sub-beam Fx2', and these are combined to form the secondary light beam Fx2. Similar to what has been described above, when the second laser emitter 32 comprises a plurality of laser light sources of distinct colors, it optionally includes at least one dichroic mirror 33. The secondary light beam Fx2, in particular each of the secondary light sub-beams Fx2', is then directed towards the reflective surface of the oscillating mirror device 4, where it forms a secondary light spot Tx2.

[0035] Specifically, within the first laser emitter 31 and / or the second laser emitter 32, the individual laser light sources are controlled independently of each other. In particular, each light source can be switched on or off independently of the switching on or off of the other light sources. Similarly, the first laser emitter 31 and the second laser emitter 32 are capable of being switched on independently of each other.

[0036] The oscillating mirror device 4 is configured to reflect at least one primary light beam Fx1 emitted by the first laser emitter 31 and at least one secondary light beam Fx2 emitted by the second laser emitter 32 towards the projection surface 2 in order to form a final image Ifx on the projection surface 2. By extension, the oscillating mirror device 4 is capable of reflecting at least one primary light beam Fx1 alone when the second laser emitter 32 is deactivated, and vice versa. It should be noted that, when the optical system 1 includes an optical device 5, the oscillating mirror device 4 is configured to reflect at least one primary light beam Fx1 and at least one secondary light beam Fx2 towards said optical device 5, which is capable of projecting said beams onto the projection surface 2, as further detailed below.

[0037] In particular, according to the invention, the first laser emitter 31 and the second laser emitter 32 are arranged and / or configured such that at least one primary light beam Fx1 and at least one secondary light beam Fx2 reach the oscillating mirror device 4 at different angles, i.e., they are separated by a non-zero gap. To this end, said emitters may be arranged at a non-zero distance from each other. For clarity, Figure 2 schematically and in a simplified manner illustrates the propagation of the primary light beam Fx1 and the secondary light beam Fx2 towards the oscillating mirror device 4.

[0038] Here, a primary incident beam Fi1 of the primary light beam Fx1 is represented by a principal primary incident direction of said beam, corresponding to the mean axis of the rays forming at least one primary light beam Fx1, on which said beam is centered, propagating between the first laser emitter 31 and the oscillating mirror device 4, in particular the primary light spot Tx1 projected onto the reflective surface of said device. Similarly, a secondary incident beam Fi2 of the secondary light beam Fx2 is represented by a principal secondary incident direction of said beam, corresponding to the mean axis of the rays forming at least one secondary light beam Fx2, on which said beam is centered, propagating between the second laser emitter 32 and the oscillating mirror device 4, in particular the secondary light spot Tx2 projected onto the reflective surface of said device.

[0039] Optionally, to optimize and simplify the scanning process, the primary light spot Tx1 and the secondary light spot Tx2 are coincident or substantially coincident within the reflective surface of the oscillating mirror device 4. According to an alternative (not shown), these spots may not coincide or may be partially coincident. The first laser emitter 31 and the second laser emitter 32 are thus able to emit the primary light beam Fx1 and the secondary light beam Fx2 respectively at the same area of ​​the reflective surface of the oscillating mirror device 4.

[0040] The non-zero spacing between these beams corresponds to a non-zero incident separation angle Ks', located between the primary incident principal direction and the secondary incident principal direction. In other words, the primary incident beam Fi1 and the secondary incident beam Fi2 reach the reflecting surface, specifically at the same point of incidence Pix located within the primary light spot Tx1 and the secondary light spot Tx2, at distinct angles of incidence. Conventionally, these angles of incidence are measured between the incident beam of the light beam under consideration and a representative axis of the normal passing through the point of incidence.

[0041] In other words, the first laser emitter 31 and the second laser emitter 32 are thus capable of emitting at least one primary light beam Fx1 and at least one secondary light beam Fx2 respectively, such that the reflected at least one primary light beam Fx1 and the reflected at least one secondary light beam Fx2, i.e., those exiting the oscillating mirror device 4, are separated by a non-zero exit angle Ks, said angle being contained between principal directions inherent to the reflected at least one primary light beam Fx1 and the reflected at least one secondary light beam Fx2. These reflected beams originate, for example, from the point of incidence Pix contained within the primary light spot Tx1 and the secondary light spot Tx2.

[0042] This principle allows the primary light beam Fx1 and the secondary light beam Fx2 to be projected onto distinct portions of the projection surface 2, particularly at a given instant. Specifically, the invention allows, as further described below with reference to Figures 3 to 5, the projection surface 2 to be divided into as many portions as there are distinct laser emitters spatially separated from one another, i.e., arranged at a non-zero distance from each other, each laser emitter projecting at least one light beam onto one of these portions. The first laser emitter 31 is thus capable of projecting information or an image onto a first portion Px1 of the projection surface 2, while the second laser emitter 32 is capable of projecting information or an image onto a second portion Px2 of the projection surface 2.As described below according to alternative embodiments of the invention, said portions can be adjacent so as to be joined together, forming a continuous display surface. This principle makes it possible, in particular, to reconstruct the same overall image, at the scale of the projection surface 2, from the different illuminated portions of said surface and the different laser emitters. Alternatively, said portions can be separated by a greater or lesser distance, or said surfaces can be partially superimposed.

[0043] Preferably, the first laser emitter 31 and the second laser emitter 32, particularly the emission zones of the at least one primary light beam Fx1 and the at least one secondary light beam Fx2 respectively, are configured so as to have a spacing such that the at least one primary incident beam Fi1 and the secondary incident beam Fi2, arriving at the level of the oscillating mirror device 4, are separated from each other by an incident separation angle Ks' strictly greater than 4.00°, said angular sector being defined in particular by two half-lines passing through at least a part of the first laser emitter 31 and the second laser emitter 32 respectively and passing through the point of incidence Pix or, as described above, relative to the principal incident directions of said light beams.Here, "spacing" refers to a pointing difference between the at least one primary light beam Fx1 and the at least one secondary light beam Fx2, also described as an angular offset or deviation. Put another way, or as stated above, the first laser emitter 31 and the second laser emitter 32 are configured such that the at least one reflected primary light beam Fx1 and the at least one reflected secondary light beam Fx2, exiting the oscillating mirror device 4, are separated by an exit separation angle Ks with a non-zero value strictly greater than 4.00°.

[0044] Such a minimum spacing value between the different laser sources is defined on the basis of standard NF EN 60825-1 / A2 relating to the safety of laser devices, which defines that a dilated human pupil measures at most 7 mm in diameter and that the safety level of a human eye perceiving a light beam from a laser emitter is assessed at its closest when the eye is placed 10 cm from said laser emitter, such a distance corresponding to the near point, i.e., the smallest distance of accommodation of the eye. Under such conditions, the eye is able to perceive a light beam contained within a perception area Sxp delimited by a visual angle Vx measuring at most 4°, as illustrated in the figure.Therefore, to ensure the user's eye safety, it is essential to guarantee that, at any given moment, the light power perceived by the user within the viewing area is strictly less than a predefined maximum permissible power. Thus, if at least one primary light beam Fx1 and / or at least one secondary light beam Fx2 have a pointing angle strictly greater than 4.00°, that is, an angular shift or deviation relative to each other, the total light energy emitted at a given instant t by the first laser emitter 31 and the second laser emitter 32 cannot enter the eye simultaneously.The present invention thus ensures that, during the operation of the optical system and at any given instant, the eye of an observer perceives, within the perception surface Sxp, only the light beam from one of the laser emitters out of the plurality of laser emitters, while retinal persistence allows the perception of an image projected onto the entire projection surface 2, and therefore onto the different portions of said surface by the different laser emitters. This principle, as further explained below, makes it possible to project information with greater contrast than prior art optical systems, while using laser emitters whose power is adapted to standards so as to ensure the ocular safety of an observer.

[0045] Specifically, the first laser emitter 31 and the second laser emitter 32 are configured so that the outgoing separation angle Ks and / or the incident separation angle Ks' has a value less than or equal to 45.00°, or even less than or equal to 30.00° or less than or equal to 15.00°. For example, the outgoing separation angle Ks and / or the incident separation angle Ks' has a value in the range of 5.00° to 10.00°.

[0046] The oscillating mirror device 4 includes, in a conventional manner, a movable scanning mirror capable of reflecting at least one primary light beam Fx1 and / or at least one secondary light beam Fx2 at a given instant, depending on whether the first laser emitter 31 and / or the second laser emitter 32 is activated, according to the angle of rotation at which it is positioned. The oscillating mirror device 4 also includes a mechanical device for oscillating the mirror. The scanning mirror can be of any known type and driven using conventional drive methods.As further described below, the scanning mirror is moved within a defined scanning area so as to move at least one primary light beam Fx1 and at least one secondary light beam Fx2 within the defined projection surface 2, specifically within the first portion Px1 and the second portion Px2 of the projection surface 2, respectively, when the first laser emitter 31 and the second laser emitter 32 are activated. Indeed, due to the spacing between these light beams, they have, on the one hand, distinct incident angles relative to the oscillating mirror device 4 and, on the other hand, distinct reflection angles, so that they are reflected towards distinct areas, here portions, of the projection surface 2 at any given instant.

[0047] Thus, for each position of the scanning mirror, at least one primary light beam Fx1 and at least one secondary light beam Fx2 are reflected in a given direction of their own on the projection surface 2, that is to say here so as to present distinct positions within the area delimited between the proximal limit Lp and the distal limit Ld on the one hand and the first extreme edge B1 and the second extreme edge B2 on the other hand.

[0048] When the first laser emitter 31 is activated, it emits at least one primary light beam Fx1 towards the reflecting surface of the oscillating mirror device 4, where it forms the primary light spot Tx1. This primary light beam Fx1 is reflected towards the first portion Px1 of the projection surface 2, the scanning of the oscillating mirror device 4 thus enabling the movement of at least one primary light beam Fx1 within the first portion Px1 of the projection surface 2, as further explained below. Similarly, when the second laser emitter 32 is activated, it emits at least one secondary light beam Fx2 towards the reflecting surface of the oscillating mirror device 4, where it forms the secondary light spot Tx2, which is in particular coincident or substantially coincident with the primary light spot Tx1.The said secondary light beam Fx2 is reflected towards the second portion Px2 of the projection surface 2, the scanning of the oscillating mirror device 4 thus allowing the movement of at least one secondary light beam Fx2 within the second portion Px2 of the projection surface 2 concomitantly with the movement of at least one primary light beam Fx1 within the first portion Px1 of the projection surface 2.

[0049] The first laser emitter 31 and the second laser emitter 32 are capable of being activated independently of each other and can project their respective light beams individually or simultaneously. Similarly, as further explained below, the color and / or intensity of the primary light beam Fx1 and the secondary light beam Fx2 can be modified during the scanning of the oscillating mirror device 4. At any given instant, the primary light beam Fx1 thus projects a primary partial image Ipx1 onto the first portion Px1 of the projection surface 2, while the secondary light beam Fx2 is projected onto the second portion Px2 of said surface, forming a secondary partial image Ipx2.

[0050] Each position of the scanning mirror of the oscillating mirror device 4 thus forms, at a given instant, a partial image Ipx composed of a primary partial image Ipx1 and / or a secondary partial image Ipx2 depending on the activated laser emitter(s). According to various embodiments described below, the primary partial image Ipx1 and the secondary partial image Ipx2 can be inscribed within a part of a common pattern forming the partial image Ipx, so as to define distinct, complementary portions of said pattern, or they can be inscribed within separate patterns.The superposition of different partial images Ipx, resulting from the various positions of the oscillating mirror device 4, forms a final image Ifx perceived by a user on the projection surface 2. This final image can be a single pattern, corresponding to the combination of the shapes projected onto the first portion Px1 and the second portion Px2 of the projection surface 2, or it can be separate patterns. Indeed, due to the persistence of vision, the observer does not distinguish the partial images Ipx, but perceives the final image Ifx, resulting from their superposition.

[0051] For example, the oscillating mirror device 4 is of the MEMS type, from the English "Micro Electro Mechanical Systems" meaning "micro-electromechanical system", allowing each of the incident light beams to be oriented according to a plurality of angular orientations over time.

[0052] According to one embodiment, the oscillating mirror device 4 is configured to perform a sequential two-dimensional scan along lines to form an image on the projection surface 2, also known as a raster scan. The mechanical mechanism of the oscillating mirror device 4 allows the scanning mirror to oscillate within the defined scanning area along a first axis and a second axis orthogonal to each other. The movement of the oscillating mirror device 4 along the first axis is configured to allow the displacement of at least one primary light beam Fx1 and at least one secondary light beam Fx2 along the first direction 100, visible at 4, within the projection surface 2, i.e., here between the proximal limit Lp and the distal limit Ld, respectively in the first portion Px1 and the second portion Px2.The displacement of the oscillating mirror device 4 along the second axis is configured to allow a displacement of at least one primary light beam Fx1 and at least one secondary light beam Fx2 along the second direction within the projection surface 2, i.e. here between the first extreme edge B1 and a first intermediate edge B1' for the primary light beam Fx1 in the first portion Px1 of the projection surface 2, and between a second intermediate edge B2' and the second extreme edge B2 for the secondary light beam Fx2 in the second portion Px2 of the projection surface 2.

[0053] In particular, in the case of a raster-type scan, an oscillation speed along the first direction 100 is strictly less than an oscillation speed along the second direction 200. The second axis thus corresponds to a fast axis along which the oscillating mirror device 4 is in resonance, specifically here a horizontal or substantially horizontal axis, while the first axis corresponds to a slow axis of mechanical detachment of the oscillating mirror device 4, specifically here a vertical or substantially vertical axis. The oscillating mirror device 4 is thus configured to assume a plurality of different angular orientations and to transition from one of these angular orientations to another at very high frequencies.

[0054] Figures 3 to 5 illustrate a non-limiting example of the path of the primary light beam Fx1 and the secondary light beam Fx2 within the projection surface 2 as a function of successive positions of the oscillating mirror device 4 for a raster scan, when the first laser emitter 31 and the second laser emitter 32 are kept on, unless otherwise specified. It is understood that the description applies mutatis mutandis to the selective actuation of the different laser emitters in order to project a desired pattern.

[0055] The path under consideration begins at the top left of each portion of the projection surface 2, at the initial points P1, P1'. The oscillating mirror device 4 is driven so that the primary light beam Fx1 is moved along a first line L1 extending parallel to the first direction 100, from the proximal limit Lp to the distal limit Ld, and contained within the first portion Px1 of the projection surface 2. At the same time, the movement of the oscillating mirror device 4 causes the secondary light beam Fx2 to move along a first line L1' extending parallel to the first direction 100, from the proximal limit Lp to the distal limit Ld, and contained within the second portion Px2 of the projection surface 2.

[0056] The first laser emitter 31 and the second laser emitter 32 are capable of being in operation as long as the oscillating mirror device 4 performs a scan along the first axis so as to move the primary light beam Fx1 and the secondary light beam Fx2 between the proximal limit Lp and the distal limit Ld of the projection surface 2 within their respective portions, the intensity of said beams being able to vary so as to allow the projection of variable information.When the primary light beam Fx1 and the secondary light beam Fx2 reach the distal limit Ld, the first laser emitter 31 and the second laser emitter 32 are switched off to allow the oscillating mirror device 4 to move along the second axis, in anticipation of the movement of said light beams along second lines L2, L2', distinct from the first lines L1, L1' and contained within the first portion Px1 and the second portion Px2 of the projection surface 2, respectively. These second lines L2, L2' extend parallel to the first direction 100 and to the first lines L1, L1' and are adjacent to them.

[0057] Next, the first laser emitter 31 and the second laser emitter 32 are capable of being put back into operation in order to allow the movement of the primary light beam Fx1 and the secondary light beam Fx2 along the second lines proper to the different portions of the projection surface 2 from the distal limit Ld of the projection surface 2 and towards the proximal limit Lp.Again, when the primary light beam Fx1 and the secondary light beam Fx2 reach the limit of the projection surface 2, here the proximal limit Lp, the first laser emitter 31 and the second laser emitter 32 are interrupted in order to allow the movement of the oscillating mirror device 4 along the second axis, in anticipation of the movement of the primary light beam Fx1 and the secondary light beam Fx2 along third lines L3, L3', distinct from the first lines L1, L1' and second lines L2, L2', and extending parallel to these and to the first direction 100.

[0058] This principle is repeated for a plurality of lines extending parallel to the first direction 100 until a final position of the primary light beam Fx1 and the secondary light beam Fx2, here for example represented at the bottom left of each portion of the projection surface 2 by the endpoints Pf, Pf'. The first laser emitter 31 and the second laser emitter 32 are able to be kept in operation for the duration of the movement of the primary light beam Fx1 and the secondary light beam Fx2 along each line considered, corresponding to a sweep of the oscillating mirror device 4 along the first axis and to a movement of the primary light beam Fx1 and the secondary light beam Fx2 from the proximal limit Lp to the distal limit Ld, here in the case of lines with an odd number, or vice versa in the case of lines with an even number.

[0059] The operation of the first laser emitter 31 and the second emitter is interrupted each time the primary light beam Fx1 and the secondary light beam Fx2 reach one of the limits of the projection surface 2 in order to allow the execution of a displacement of the oscillating mirror device 4 along the second direction 200 and the transition from a line n to an adjacent line n+1. When the primary light beam Fx1 and the secondary light beam Fx2 reach the endpoints Pf, Pf', the laser emitter 3 is switched off and the oscillating mirror device 4 is moved in order to return to its initial, or nominal, position.

[0060] According to an alternative embodiment, the oscillating mirror device 4 is configured to implement a Lissajous-type scan. Similar to what has been described above, the mechanical device 42 of the oscillating mirror device 4 allows the scanning mirror 41 to oscillate within the scanning area so as to move the primary light beam Fx1 and the secondary light beam Fx2 within the projection surface 2 when the first laser emitter 31 and the second laser emitter 32 are operating. In a known manner, a Lissajous curve is followed by driving the scanning mirror 41 along two orthogonal axes, namely a first axis and a second axis, with a monotonic sinusoidal waveform of constant amplitude along each axis. Conventionally, the characteristics of the Lissajous trajectory are determined by the frequency and phase of the two orthogonal sinusoidal waveforms.

[0061] The eye safety of an observer depends on the light power they detect in the perception surface Sxp at a given instant, that is, here, for the tracing of a line determined by one of the laser emitters or of several given lines traced by several of the laser emitters. Due to the non-zero spacing separating the at least one primary light beam Fx1 and the at least one secondary beam Fx2, in particular the lines traced by these beams respectively in the first portion Px1 and the second portion Px2 of the projection surface 2, at each instant t considered, the observer's eye is only able to detect one of the lines being traced, among a plurality of lines each traced by one of the laser emitters 31, 32.

[0062] Advantageously, due to the increased number of laser emitters and the greater number of sections within the projection surface 2, the lines traced within a given section are closer together than in prior art scanning systems. Consequently, the illumination—that is, the quantity of lumens—of the final image Ifx detected by the eye due to retinal persistence is increased or multiplied compared to a final image projected by a prior art optical system, while still ensuring the eye safety of an observer as long as each laser emitter has a maximum power output that complies with the standards. The same applies to the contrast of the final image Ifx.

[0063] Regardless of the scanning method used, the oscillating mirror device 4 is defined by at least one oscillation amplitude Akx, corresponding to a displacement amplitude, or maximum displacement angle, of said mirror between two opposite extreme positions along at least one direction. The direction considered corresponds to the direction in which the different portions of the projection surface 2 are arranged one after the other or adjacent to each other.

[0064] In this case, the first portion Px1 and the second portion Px2 are arranged side by side when moving along the second direction 200, and the oscillation amplitude Akx is therefore defined along the second axis. The oscillation amplitude Akx of the oscillating mirror device 4 during its sweep along the second axis thus corresponds to the maximum angle of displacement of said device between a first sweep line and a last sweep line within the considered portion of the projection surface 2. In the illustrated example, the oscillation amplitude Akx is defined between the first sweep line L1 of the primary light beam Fx1 within the first portion Px1, corresponding to the line parallel to the first direction closest to the first extreme edge B1, and a last line, parallel to the first direction and closest to the first intermediate edge B1'.The oscillation amplitude Akx can be defined similarly for the secondary light beam Fx2 within the second portion Px2 of the projection surface 2 relative to the second intermediate edge B2' and the second extreme edge B2.

[0065] The relationship between the oscillation amplitude angle Akx, here along the second axis, and the outgoing separation angle Ks and / or the incident separation angle Ks' defines the relative position of the first portion Px1 and the second portion Px2 of the projection surface 2.

[0066] Figures 3 and 4 illustrate a first example of an embodiment of the invention in which the optical system 1 is configured such that the outgoing separation angle Ks and / or the incident separation angle Ks' separating the at least one primary light beam Fx1 and the at least one secondary light beam Fx2 is equal to, or substantially equal to, the angle of the oscillation amplitude Akx of the oscillating mirror device 4, here along the second axis, i.e. allowing the displacement of the primary light beam Fx1 and the secondary light beam Fx2 along the second direction 200. Such a principle makes it possible to obtain a first portion Px1 and a second portion Px2 of the projection surface 2 which are adjacent and glued to each other, the first intermediate edge B1' of the first portion Px1 and the second intermediate edge B2' of the second portion Px2 being coincident or substantially coincident.Such a relative arrangement of the first portion Px1 and the second portion Px2 thus results in a negligible overlap or spacing between said portions, so as to form a continuous projection surface 2. This principle is, for example, implemented for projecting information onto the road surface, particularly in front of the vehicle 10, for projecting information onto the dashboard for the driver or passengers of the vehicle, or for warning road users, for example, those in neighboring vehicles.

[0067] This illustrates a second embodiment of the invention in which the optical system 1 is configured such that the outgoing separation angle Ks and / or the incident separation angle Ks' separating the at least one primary light beam Fx1 and the at least one secondary light beam Fx2 is strictly greater than the oscillation amplitude angle Akx of the oscillating mirror device 4, particularly here along the second axis. This principle allows for the formation of a first portion Px1 and a second portion Px2 that are adjacent but spaced apart, i.e., separated from each other by a non-zero distance. The first intermediate edge B1' of the first portion Px1 and the second intermediate edge B2' of the second portion Px2 are thus separated by a non-zero distance.Such a relative arrangement of the first portion Px1 and the second portion Px2 thus results in a non-negligible gap between said portions which can be implemented, for example, for the projection of information onto the roadway, for projecting information onto the dashboard for the attention of different vehicle users or for warning road users, for example those present in neighboring vehicles.

[0068] According to a third embodiment of the invention, not shown, the outgoing separation angle Ks and / or the incident separation angle Ks' separating the at least one primary light beam Fx1 and the at least one secondary light beam Fx2 is strictly less than the oscillation amplitude angle Akx of the oscillating mirror device 4, particularly along the second axis. This principle allows for a first portion Px1 and a second portion Px2 that are adjacent but partially overlap, i.e., they are at least partially superimposed, for example, to allow for over-illumination of the overlapping area. Such over-intensity is particularly beneficial in the case of daytime lighting, where the illuminance must be significantly greater to be visible.

[0069] As is known, the control unit 42 is also configured to vary an intensity of the primary light beam Fx1, emitted by the first laser emitter 31, and / or an intensity of the secondary light beam Fx2, emitted by the second laser emitter 32 as the scan is performed in order to define the pattern or information to be projected according to the position of the oscillating mirror device 4.

[0070] Optionally, regardless of the scanning type of the oscillating mirror device 4 implemented, the control unit 42 is also configured to vary the intensity of the primary light beam Fx1, emitted by the first laser emitter 31, and / or the intensity of the secondary light beam Fx2, emitted by the second laser emitter 32, according to the position of the oscillating mirror device 4 and / or according to the position of the primary light beam Fx1 and the secondary light beam Fx2 within the projection surface 2, so as to ensure homogeneous illumination within said projection surface 2. In other words, such a variation in the intensity of said beams makes it possible to ensure suitable and homogeneous illumination of the final image Ifx perceived on the projection surface 2. Indeed, the illumination of an area of ​​the final image Ifx projected onto the projection surface 2 depends on the light intensity and the projection distance.Typically, for a constant light intensity, illuminance decreases with projection distance. Here, "projection distance" refers, for example, to the distance between the pivot point of the oscillating mirror 4 and a point on the projection surface 2 onto which the light beam Fx is projected at a given instant. Indeed, due to the grazing effect and the movement of the oscillating mirror 4, the projection distance is subject to change.Also, according to a preferred example, in order to ensure homogeneity of illumination within the projection surface 2, the luminous intensity of the primary light beam Fx1 and / or of the secondary light beam Fx2 increases proportionally to the projection distance as a function of the position of the oscillating mirror device 4 at a given instant so as to ensure homogeneity of illumination within each portion of the projection surface 2 considered and / or between the different portions.

[0071] Optionally, the optical projection system 1 according to the invention further comprises at least one optical device 5 disposed downstream of the oscillating mirror device 4 in a direction of propagation of the primary light beam Fx1 and / or the secondary light beam Fx2.

[0072] The optical device 5 comprises at least one first optical assembly 6. For example, the first optical assembly 6 comprises a primary projection lens or a plurality of primary projection lenses. Due to the scanning performed by the oscillating mirror device 4, the latter reflects, at a given instant, the primary light beam Fx1 and / or the secondary light beam Fx2 onto a portion of the first optical assembly 6 for each position of said device.

[0073] Optionally, the optical device 5 further comprises a second optical assembly 7, arranged downstream of the first optical assembly 6 along the propagation direction of the primary light beam Fx1 and / or the secondary light beam Fx2. In one embodiment, the second optical assembly 7 comprises at least one secondary projection lens. Alternatively, the second optical assembly 7 comprises at least one secondary mirror. For example, the second optical assembly 7 comprises a plurality of secondary mirrors, at least one of which is a reflecting mirror.

[0074] According to a particular embodiment, optional, the optical device 5 comprises the first optical assembly 6, the second optical assembly 7 and a translucent screen 8, interposed between the first optical assembly 6 and the second optical assembly 7.

[0075] In particular, as illustrated in the figure, the translucent screen 8 is arranged so that an entrance face 81 of said screen is turned towards the first optical assembly 6 while an output face 82 of said screen, opposite the entrance face 81, is turned towards the second optical assembly 7. The first optical assembly 6 is then interposed between the oscillating mirror device 4 and the translucent screen 8 so that it is configured to form a first intermediate image Imx1 of the primary light spot Tx1 and a second intermediate image Imx2 of the secondary light spot Tx2 on the output face 82 of the translucent screen 8 at a given instant.The second optical assembly 7 is thus configured to project, or image, the first intermediate image Imx1 and the second intermediate image Imx2 onto the projection surface 2, respectively onto the first portion Px1 and the second portion Px2, so as to form the primary partial image Ipx1 and the secondary partial image Ipx2, which together form the final image Ifx. As explained above, according to non-limiting embodiment examples, the projection surface 2 is optionally an inclined surface, particularly with respect to the second optical assembly 7 and / or with respect to the translucent screen 8.

[0076] The translucent screen 8 is interposed between the second optical assembly 7 and the oscillating mirror device 4. Thus, when an observer's eye views the optical system 1 according to the invention, it perceives the primary light beam Fx1 and the secondary light beam Fx2 at the level of the second optical assembly 7 and / or the first and second intermediate images Imx1, Imx2 projected onto the translucent screen 8, instead of directly perceiving the primary light spot Tx1 and the secondary light spot Tx2 projected onto the oscillating mirror device 4, regardless of whether the eye is at rest or in the accommodation phase, also known as focusing. This principle thus advantageously optimizes the eye safety of an observer located near the optical system 1 or the vehicle 10, in addition to the eye safety afforded by the presence of multiple laser emitters spaced apart from one another.

[0077] In particular, the translucent screen 8 is arranged so that an image focus F1i of the first optical assembly 6 is located on the output face 82 of the translucent screen 8 or substantially on the output face 82. Here, "substantially" means that the position of the image focus F1i of the first optical assembly 6 is located at ±1.00 mm, or even at ±500 µm or ±300 µm from the output face 82 of the translucent screen 8.

[0078] Optionally, the translucent screen 8 is arranged so that an object focus F2o of the second optical assembly 7 is located at the exit face 82 of the translucent screen 8, specifically so that it coincides with the image focus F1i of the first optical assembly 6. This principle can be implemented, in particular, when at least one primary light beam Fx1 and at least one secondary light beam Fx2 are collimated. Rays forming each of these light beams exiting the second optical assembly 7 then extend parallel or substantially parallel to each other. In particular, the optical device 5 is then afocal.

[0079] Alternatively, the translucent screen 8 is arranged so that the object focus F2o of the second optical assembly 7 extends between the output face 82 of the translucent screen 8 and the second optical assembly 7. More specifically, the object focus F2o of the second optical assembly 7 is located between the image focus F1i of the first optical assembly 6 and the second optical assembly 7. This principle can be implemented, in particular, in the case of a primary light beam Fx1 and a secondary light beam Fx2 that are not collimated and converge downstream of the output face 82 of the translucent screen 8, according to the direction of propagation of said beams. This principle is notably implemented when projecting information onto a projection surface 2 located at a given, predefined projection distance. Rays emanating from each of said beams exiting the second optical assembly 7 then converge towards each other.Such a principle makes it possible to optimize the resolution and sharpness of the projected information and to optimize the eye safety of an observer due to the presence of the translucent screen 8 by preventing the eye from accommodating on the oscillating mirror device 4.

[0080] Thus, for example, the object focus F2o of the second optical assembly 7 is separated from the image focus F1i of the first optical assembly 6 by a distance less than or equal to 1.00 mm, or even less than or equal to 300 µm, such a distance being zero when said foci are coincident, as indicated above, and not zero when said foci are distinct.

[0081] In particular, a distance separating the output face 82 of the translucent screen 8 of the second optical assembly 7, for example from a surface of at least one adaptive projection lens 51, is defined by the following relation:

[0082]

[0083] Or :

[0084] De_opt2 is the distance separating the output face 82 from the translucent screen 8 of the second optical assembly 7;

[0085] df2 is the focal length of the second optical assembly 7, in particular of at least one adaptive projection lens 51;

[0086] dpj is the distance between the second optical assembly 7, for example at the surface of at least one adaptive projection lens 51, and the projection surface 2.

[0087] The translucent screen 8 has, in particular, a diffuser function, that is to say, it partially diffuses or splits the primary light beam Fx1 and the secondary light beam Fx2 and modifies, particularly increases, the angular size and the size of the retinal image of the final image Ifx relative to the size of the primary light spot Tx1 and the secondary light spot Tx2 projected onto the oscillating mirror device 4. For an external observer, the first intermediate image Imx1 and the second intermediate image Imx2 projected onto the translucent screen 8 are then the images of the projected sources and become the point of accommodation of the observer's eye, for accommodation at infinity of the eye or even for the eye at rest and this even in case of failure or blockage of the oscillating mirror device 4.

[0088] Optionally, the second optical assembly 7 allows the size of the final image Ifx, projected onto the target projection surface 2, to be increased relative to the size of the first intermediate image Imx1 and the second intermediate image Imx2. The size of the primary light beam Fx1 and the size of the secondary light beam Fx2 are thus greater at the output of the optical system 1, i.e. downstream of the second optical assembly 7, than at its input, i.e. upstream of the oscillating mirror device 4.

[0089] According to embodiment examples, the translucent screen 8 is made of a material selected from glass, plastic such as polycarbonate, or ceramic. For example, the translucent screen 8 is obtained by injection molding, overmolding, and / or photolithography. It is, for example, dimensioned so as to have a surface area greater than or equal to the surface area of ​​the first optical assembly 6, for example, the primary projection lens, and / or greater than or equal to a reflective surface area of ​​the oscillating mirror device 4.

[0090] Preferably, the translucent screen 8 has a transmission coefficient greater than or equal to 80%. Specifically, the transmission coefficient is measured conventionally by flux measurement with an integrating sphere and without passage through the translucent screen 8.

[0091] The translucent screen 8 also serves as at least partial obstruction, preventing direct visibility of the oscillating mirror device 4, and particularly of the primary light spot Tx1 and the secondary light spot Tx2 projected onto it. Preferably, the translucent screen 8 is defined by an optical blur level greater than or equal to 15%. "Optical blur" refers to a haze, also known as reflection mist or "haze." The "optical blur level" is defined as the percentage of light scattered outside a 2.5° cone centered on an optical axis of the optical system 1. Thus, the primary light beam Fx1 and the secondary light beam Fx2 are able to propagate through the translucent screen 8, but accommodation of the observer's eye to the oscillating mirror device 4 is not possible.

[0092] According to examples of implementation, the translucent screen 8 exhibits an optical blur of surface, volume or holographic type.

[0093] A translucent screen 8 of surface type has a haze at least on one of its faces, in particular at least on its exit face 82. Preferably, such a translucent screen 8 has an optical blur level greater than or equal to 15%.

[0094] A volumetric translucent screen 8 exhibits haze over all or part of a thickness of the translucent screen 8, corresponding to the dimension between the entrance face 81 and the exit face 82. Preferably, the translucent screen 8 then exhibits a level of optical blur greater than or equal to 20%, or even 22%.

[0095] A translucent holographic screen 8 comprises patterns or microstructures, optionally combined with a haze, particularly at the exit face 82. Specifically, these patterns or microstructures have a regular periodicity. Preferably, the translucent screen 8 then exhibits an optical blur level greater than or equal to 25%, or even 27%.

[0096] Optionally, all or part of a thickness of the translucent screen 8, between the inlet face 81 and the outlet face 82, has a heterogeneous structure.

[0097] In particular, the heterogeneous structure of the translucent screen 8 comprises a plurality of microstructures selected from:

[0098] - heterogeneous graining arranged at the level of all or part of the exit face 82 82; and / or- a plurality of microscopic prisms; and / or- an irregular heterogeneous holographic pattern.

[0099] The heterogeneous structure of the translucent screen 8 thus depends on its texturing.

[0100] The term "graining" refers to the fact that the translucent screen 8, particularly the exit face 82, comprises a plurality of grains. The heterogeneity of the structure is then obtained through heterogeneity of shape, size, and refractive index of said grains and / or heterogeneity of distribution or density of said grains within the translucent screen 8. For example, the grains have dimensions on the order of 1 to 10 µm.

[0101] The term "microscopic prisms" refers to the translucent screen 8, particularly the exit face 82, comprising a plurality of polyhedra whose dimensions can be on the order of 1 to 10 µm. The heterogeneity of the structure is then obtained by heterogeneity of shapes, dimensions, refractive index, and / or distribution, or density, of said prisms within the translucent screen 8.

[0102] The term "holographic pattern" refers to the translucent screen 8, particularly the output face 82, comprising a plurality of holograms corresponding to microstructures with a regular period. The heterogeneity of the structure is thus obtained through heterogeneity of shape, size, inclination, refractive index, and / or distribution, or density, of said holograms within the translucent screen 8.

[0103] The invention also extends to a method for projecting at least one beam of light onto a projection surface 2 by means of an optical system 1 according to the invention. Such a method can also be described as a method for controlling an optical system 1 according to the invention or as a method for operating a vehicle 10 equipped with such an optical system 1. It is understood that the above description, relating to the optical system 1, applies mutatis mutandis to the method and vice versa.

[0104] The method comprises projecting at least the primary light beam Fx1, emitted by the first laser emitter 31, and at least the secondary light beam Fx2, emitted by the second laser emitter 32, onto the reflecting surface of the oscillating mirror device 4, such that these beams are reflected respectively towards the first portion Px1 and the second portion Px2 of the projection surface 2, at least partially distinct, in particular at the same instant. The control unit 42 is capable of varying the intensity of the primary light beam Fx1 and / or the intensity of the secondary light beam Fx2 during the scanning process, i.e., in synchronization with the movement of the oscillating mirror device, in order to define the pattern or information to be projected as a function of the position of the oscillating mirror device 4, as described above.Optionally, the control unit is capable of varying the light intensity of the primary light beam Fx1 and / or the secondary light beam Fx2 proportionally to the projection distance as a function of the position of the oscillating mirror device 4 at a given instant so as to ensure homogeneity of illumination within each portion of the projection surface 2 considered and / or between the different portions.

[0105] In particular, as set out above with reference to optical system 1, the process is carried out so that the projection of at least one primary light beam Fx1 and at least one secondary light beam Fx2 is implemented by a sequential two-dimensional scan along lines to form an image on the projection surface 2, also referred to as a "raster" type scan, or by a "Lissajous" type scan as described above.

[0106] The invention thus proposes an optical system comprising a plurality of laser emitters spatially separated from one another and configured to illuminate at least partially distinct portions of a projection surface as a function of a sweep by an oscillating mirror device. The optical system according to the invention advantageously enables the projection of information with improved contrast and higher illumination while ensuring the eye safety of an observer.

[0107] The present invention is not limited to the means and configurations described and illustrated herein, and also extends to any equivalent means or configuration and to any technically operative combination of such means insofar as they fulfill the functionalities described and illustrated in this document.

Claims

Optical projection system (1) comprising at least a first laser emitter (31), a second laser emitter (32) and an oscillating mirror device (4): - the first laser emitter (31) being configured to emit a primary light beam (Fx1) and the second laser emitter (32) being configured to emit a secondary light beam (Fx2), capable of forming respectively a primary light spot (Tx1) and a secondary light spot (Tx2) on the oscillating mirror device (4), the first laser emitter (31) and the second laser emitter (32) being configured such that the primary light beam (Fx1) and the secondary light beam (Fx2) reach the oscillating mirror device (4) at different angles and such that an incident separation angle (Ks') separating said beams upstream of the oscillating mirror device (4),and / or an outward separation angle (Ks) separating said beams downstream of the oscillating mirror device (4) has a non-zero value; - the oscillating mirror device (4) being configured to reflect the primary light beam (Fx1) and the secondary light beam (Fx2) respectively towards a first portion (Px1) and a second portion (Px2) contained within a projection surface (2) and at least partly distinct from each other. Optical projection system (1) according to the preceding claim, wherein the incident separation angle (Ks') and / or the outgoing separation angle (Ks) separating the primary light beam (Fx1) and the secondary light beam (Fx2) has a value strictly greater than 4.00°. Optical projection system (1) according to the preceding claim, wherein the oscillating mirror device (4) is defined by at least one oscillation amplitude (Akx), corresponding to a displacement amplitude of said mirror between two opposite extreme positions along at least one direction, the incident separation angle (Ks') and / or the outgoing separation angle (Ks) being equal to, or substantially equal to, an angle of the oscillation amplitude (Akx) of the oscillating mirror device (4) corresponding to a displacement amplitude of said mirror between two opposite extreme positions along at least one direction. Optical projection system (1) according to claim 2, wherein the oscillating mirror device (4) is defined by at least one oscillation amplitude (Akx), corresponding to a displacement amplitude of said mirror between two opposite extreme positions along at least one direction: - the incident separation angle (Ks') and / or the outgoing separation angle (Ks) being strictly greater than an angle of the oscillation amplitude (Akx) of the oscillating mirror device (4) so ​​that the primary light beam (Fx1) and the secondary light beam (Fx2) are projected onto adjacent portions of the projection surface (2) separated by a non-zero spacing;or- the incident separation angle (Ks') and / or the outgoing separation angle (Ks) being strictly less than an angle of the oscillation amplitude (Akx) of the oscillating mirror device (4) so ​​that the primary light beam (Fx1) and the secondary light beam (Fx2) are projected onto portions of the projection surface (2) that are at least partially superimposed.; Optical projection system (1) according to any one of the preceding claims, further comprising a control unit (42) of the first laser emitter (31) and the second laser emitter (32) configured to vary an intensity of the first laser emitter (31) and / or the second laser emitter (32) as a function of a position of the oscillating mirror device (4) and / or as a function of a position of the primary light beam (Fx1) and the secondary light beam (Fx2) in the projection surface (2) so as to ensure homogeneity of illumination within said projection surface (2). Optical projection system (1) according to any one of the preceding claims, wherein: - the first laser emitter (31) comprises a plurality of RGB type laser light sources combining red(s), green(s) and blue(s) laser light sources enabling the combined primary light beam (Fx1) to be projected onto the oscillating mirror device (4); and / or - the second laser emitter (32) comprises a plurality of RGB type laser light sources combining red(s), green(s) and blue(s) laser light sources enabling the combined secondary light beam (Fx2) to be projected onto the oscillating mirror device (4). Optical projection system (1) according to one of the preceding claims, further comprising an optical device (5) having at least a first optical assembly (6), disposed downstream of the oscillating mirror device (4) in a direction of propagation of the primary light beam (Fx1) and / or the secondary light beam (Fx2). Optical projection system (1) according to any one of claims 1 to 6, comprising an optical device (5) having a first optical assembly (6), a second optical assembly (7) and a translucent screen (8), interposed between the first optical assembly (6) and the second optical assembly (7): - the translucent screen (8) having an entrance face turned towards the first optical assembly and an exit face, opposite to the entrance face, and turned towards the second optical assembly (7); - an image focus of the first optical assembly (6) being disposed on the exit face of the translucent screen, so that the first optical assembly (6) is configured to form a first intermediate image of the primary light spot (Tx1) and a second intermediate image of the secondary light spot (Tx2) on the exit face of the translucent screen (8);and- the second optical assembly (7) being configured to project onto a projection surface (2) an image of said intermediate images.; Optical projection system (1) according to any one of the preceding claims, wherein the oscillating mirror device (4) comprises a movable scanning mirror and a mechanical drive means: - the oscillating mirror device (4) being configured to implement a "raster" type scan, the mechanical means being capable of oscillating the scanning mirror about a first axis and a second axis extending perpendicularly to each other, an oscillation speed of the oscillating mirror device (4) along the first axis being higher than an oscillation speed of said device along the second axis; or - the oscillating mirror device (4) being configured to implement a "Lissajous" type scan, the mechanical means being capable of oscillating the oscillating mirror device (4) about two orthogonal axes, according to a monotonic sinusoidal waveform with constant amplitude in each axis. Method of projecting a light beam onto a projection surface (2) by means of an optical system (1) according to any one of the preceding claims, comprising the projection of at least one primary light beam (Fx1), emitted by the first laser emitter (31), and at least one secondary light beam (Fx2), emitted by the second laser emitter (32), towards the oscillating mirror device (4) such that these are respectively reflected towards the first portion (Px1) and the second portion (Px2) of the projection surface (2), at least partly distinct, in particular at the same instant.

Images