Light projection system and light projection method.

Abstract

A light projection system (1) comprising the following elements: - a light source (2) emitting a light beam, - a scanning device (3), - a semi-reflective device (4), the semi-reflective device (4) being arranged and / or configured so that the light projection system (1) simultaneously produces: - a first image at a first location (61), and - a second image at a second location (62). Figure for the abbreviation: Fig. 1

Description

Title of the invention: Light projection system and light projection method.

[0001] The present invention relates to a light projection system for a motor vehicle. The invention also relates to a method of light projection. Finally, the invention also relates to a motor vehicle equipped with such a system or implementing such a method.

[0002] In the automotive field, there is a need to project information in the form of images outside and / or inside a vehicle. For example, there is a need to project several images outside the vehicle, particularly in front of or on the sides of the vehicle. For example, there is also a need to project several images inside the vehicle, particularly in the passenger compartment.

[0003] The object of the invention is to provide a projection system and a projection method, improving upon known projection systems and methods. In particular, the invention proposes a projection system and method for projecting several images simultaneously in different locations.

[0004] According to one object, the invention proposes a light projection system comprising the following elements: - a light source emitting a beam of light, - a scanning device, - a semi-reflective device, the semi-reflective device being arranged and / or configured so that the light projection system (1) simultaneously produces: - a first image in a first place, and - a second image in a second place.

[0005] The semi-reflective device can be arranged upstream of the scanning device relative to the path of the light beam.

[0006] The semi-reflective device can be arranged downstream of the scanning device relative to the path of the light beam.

[0007] The light projection system may include at least one optical device for shaping a light beam downstream of the scanning device and the semi-reflective device relative to the path of the light beam.

[0008] The light projection system may include at least one optical device for shaping a light beam upstream of the scanning device and downstream of the semi-reflecting device relative to the path of the light beam.

[0009] The semi-reflective device can reflect between 30% and 70% of the radiation of the light beam emitted by the light source regardless of the wavelength of the light beam.

[0010] The semi-reflective device can transmit between 30% and 70% of the radiation of the light beam emitted by the light source regardless of the wavelength of the light beam.

[0011] The semi-reflective device can: - to reflect totally or almost totally certain wavelengths of the light beam, and - to transmit totally or substantially totally the other wavelengths of the light beam.

[0012] According to another object, the invention proposes a method for operating a light projection system as defined in this description, comprising the following steps: - emission of a beam of light, - variable deviation over time of the light beam so as to make it describe a solid angle, - partial reflection of the light beam, so as to produce simultaneously: - a first image in a first place, and - a second image in a second place.

[0013] The variable deflection step may take place before the partial reflection step.

[0014] The variable deflection step may take place after the partial reflection step.

[0015] According to another object, the invention proposes a motor vehicle comprising a light projection system as defined in this description and / or comprising hardware and / or software elements implementing the method as defined in this description, in particular hardware and / or software elements designed to implement the method as defined in this description.

[0016] According to a non-limiting aspect of the invention, the motor vehicle includes means for implementing the process as defined in this description.

[0017] According to another object, the invention proposes a computer program product comprising program code instructions recorded on a computer-readable medium to implement the steps of the process as defined in this description when said program is running on a computer.

[0018] The invention also relates to a computer program product downloadable from a communication network and / or stored on a computer-readable and / or computer-executable data medium. It comprises instructions which, when The program is executed by the computer, leading the computer to implement the process as defined in this presentation.

[0019] According to another object, the invention proposes a data recording medium, readable by a computer, on which is recorded a computer program comprising program code instructions for implementing the method as defined in this description.

[0020] The invention also relates to a computer-readable recording medium comprising instructions which, when executed by a computer, lead the computer to implement the process as defined in this description.

[0021] According to another object, the invention proposes a signal from a data carrier, carrying the computer program product as defined in this disclosure.

[0022] Throughout the exposition, the characteristics described in relation to a given object or an embodiment of that object may also apply to other objects.

[0023] Fig. 1 schematically illustrates a first embodiment of a motor vehicle according to the invention comprising a first embodiment of a projection system according to the invention.

[0024] Fig. 2 schematically illustrates a second embodiment of a motor vehicle according to the invention comprising a second embodiment of a projection system according to the invention.

[0025] In the figures, a coordinate system X, Y is shown. The X-axis is a projection direction (or substantially a projection direction) of the light projection system, and the Y-axis is oriented perpendicular to the X-axis. In the figures, the projection direction is oriented along -X. Alternatively, the projection direction could be oriented along X.

[0026] A first embodiment of a motor vehicle 100 according to the invention is described below with reference to [Fig. 1]. The vehicle can be a vehicle of any kind, in particular a passenger vehicle, a commercial vehicle, or a public transport vehicle.

[0027] In some applications, the X-axis may, for example, coincide with the longitudinal axis of the motor vehicle. In other applications, the X-axis may, for example, coincide with the transverse axis of the motor vehicle.

[0028] The motor vehicle 100 includes a light projection system. This system allows two images to be projected, in particular two identical and simultaneous images. In the example illustrated in [Fig. 1], the two images are projected onto surfaces 61 and 62 at the front of the motor vehicle. Alternatively, these surfaces may be located, for example: - at the rear of the motor vehicle, or - on the sides of the motor vehicle, or - inside the motor vehicle.

[0029] The light projection system 1 comprises the following elements: - a light source 2 emitting a beam of light, - a scanning device 3, and - a semi-reflective device 4, the elements, in particular the semi-reflective device 4, being arranged and / or configured so that the light projection system 1 produces: - a first image in a first place 61, and - a second image in a second place 62.

[0030] Indeed, preferably, the semi-reflective device 4 is arranged and / or configured so as to produce two light paths enabling the first and second images to be produced.

[0031] In this first embodiment, the semi-reflective device can be arranged upstream of the scanning device relative to the path of the light beam.

[0032] Furthermore, the projection system 1 may include at least one optical device 5 for shaping the light beam downstream of the semi-reflective device and upstream of the scanning device relative to the path of the light beam.

[0033] In the first embodiment, the beam from the light source 2 impacts the semi-reflective device 4. Consequently: - a first part of the beam's light is transmitted towards the scanning device 3, notably parallel to the incident beam from the light source 2, and - a second part of the beam light is reflected towards the optical device 5 which in turn reflects the light towards the scanning device 3.

[0034] Preferably, the second part is complementary to the first part after deducting the losses in the semi-reflective device 4.

[0035] The first part of the beam light and the second part of the beam light arrive at the scanning device at different angles of incidence, consequently also at different angles, i.e. in different directions.

[0036] The first part of the light from the beam illuminates a first place 61 and makes a first image appear on this first place 61.

[0037] The second part of the beam's light illuminates a second location 62 and causes a second image to appear on this second location 62.

[0038] A second embodiment of a motor vehicle 100 according to the invention is described below with reference to [Fig. 2]. The vehicle can be a vehicle of any kind, in particular a passenger vehicle, a commercial vehicle, or a public transport vehicle.

[0039] The motor vehicle 100 includes a light projection system. This system allows two images to be projected, in particular two identical and simultaneous images. In the example illustrated in [Fig. 2], the two images are projected onto surfaces 61 and 62 in front of the motor vehicle. Alternatively, these surfaces may be located, for example: - at the rear of the motor vehicle, or - on the sides of the motor vehicle, or - inside the motor vehicle.

[0040] The light projection system 1 comprises the following elements: - a light source 2 emitting a light beam, - a scanning device 3, and - a semi-reflective device 4, the elements, in particular the semi-reflective device 4, being arranged and / or configured so that the light projection system 1 produces: - a first image in a first place 61, and - a second image in a second place 62.

[0041] Indeed, preferably, the semi-reflective device 4 is arranged and / or configured so as to produce two light paths enabling the first and second images to be produced.

[0042] In this second embodiment, the semi-reflective device can be arranged downstream of the scanning device relative to the path of the light beam.

[0043] Furthermore, the projection system 1 may include at least one optical device 5 for shaping a light beam downstream of the scanning device 3 and the semi-reflective device 4 relative to the path of the light beam.

[0044] In the second embodiment, the beam from the scanning device 3 impacts the semi-reflecting device 4. As a result: - a first part of the light from the beam is transmitted towards the first place 61, in particular parallel to the incident beam from the scanning device 3, and - a second part of the light from the beam is reflected towards the optical device 5 which in turn reflects the light towards the second place 62.

[0045] Preferably, the second part is complementary to the first part after deducting the losses in the semi-reflective device 4.

[0046] The first part of the beam's light thus illuminates a first place 61 and causes a first image to appear on this first place 61.

[0047] The second part of the beam's light therefore illuminates a second place 62 and causes a second image to appear on this second place 62.

[0048] Regardless of the embodiment or variant, the first and second places do not overlap or are disjoint. Alternatively, the first and second places may partially overlap.

[0049] Regardless of the embodiment or variant, the light source 2 may include, at its output, a collimator.

[0050] Regardless of the embodiment or variant, the light source 2 is preferably a laser source. For example, the source may comprise three laser radiation emitting diodes, in particular: - a first laser diode 2R emitting red light, - a second laser diode 2G emitting green light, - a third laser diode 2B emitting blue light. Laser technology makes it possible to produce powerful radiation in a compact size and with good energy efficiency.

[0051] Preferably, each diode is associated with a reflective device for deflecting the radiation emitted by the diode. For example, - a first reflective device 21R (like a mirror) deflects the radiation emitted by diode 2R, - a second reflective device 21G (such as a dichroic blade or filter) deflects the radiation emitted by diode 2G (while allowing the radiation emitted by diode 2R to pass through), and - a third reflective device 21B (like a blade or a dichroic filter) allows the radiation emitted by diode 2B to be deflected (while allowing the radiation emitted by diodes 2R and 2G to pass through). Thus, downstream of the third reflective device 21B, we obtain a beam of light consisting of the sum of the radiation emitted by the three diodes, for example a beam of white light (when the diodes all emit a determined radiation).

[0052] Regardless of the embodiment or variant, the scanning device 3 comprises at least one motorized mirror 31. In the examples shown in Figures 1 and 2, the scanning device 3 may consist of a single micromirror 31, movable about two orthogonal axes, such as those used in optical scanning systems called "scanners". Alternatively, the scanning device may consist of two movable mirrors oscillating about orthogonal axes, arranged such that: - a first mirror directly receives the incident radiation and is mobile around a first axis so as to reflect the radiation towards a second mirror, and - the second mirror directly receives the radiation from the first mirror and is mobile around a second axis so as to reflect the radiation towards places 61 and 62 or towards the semi-reflecting device. The movements of the mirror(s) are defined so that the rays from the projection system can traverse the entirety of the first and second locations where the first and second images are to appear. The mirror(s) used may employ MEMS (microelectromechanical system) technology.

[0053] The displacement amplitudes of the mirror or mirrors of the scanning device 3 are on the order of 20°. It follows that the amplitude of variation of the direction of the beam reflected by the scanning device 3 is on the order of 40°. Consequently, the beam reflected by the scanning device 3 can sweep a solid angle on the order of half a steradian.

[0054] Regardless of the embodiment or variant, the light source 2 and the scanning device 3 are controlled synchronously to produce the desired images. Indeed, the light intensity produced by the light source 2 must vary as the image display areas are scanned. This control is, for example, performed by a computer 7 that is part of the projection system.

[0055] Consequently, the invention also relates to a method of projecting light. The method of projecting light can also be viewed as a method of operating the projection system described above or as a method of operating a motor vehicle incorporating the projection system.

[0056] The projection process comprises the following steps: - emission of a beam of light, - variable deviation over time of the light beam so as to make it describe a solid angle, - partial reflection of the light beam, so as to produce simultaneously: - a first image in the first place, and - a second image in a second location.

[0057] The emission of the light beam and the movements of the scanning device (allowing the time-varying deflection of the light beam to be produced) are synchronized so as to make the desired image appear in the first place and the second place.

[0058] In a first embodiment of the process, the variable deflection (scanning) step takes place before the partial reflection step.

[0059] In a first embodiment of the process, the variable deflection (scanning) step takes place after the partial reflection step.

[0060] In embodiments illustrated in Figures 1 and 2, the two images are projected onto surfaces 61 and 62 in front of the motor vehicle. However, regardless of the embodiment or variant, the images could be projected in other locations. For example, a first image could be projected in front of the motor vehicle and a second image could be projected onto the side of the motor vehicle. Alternatively, one or both of the images could be projected inside the motor vehicle, particularly in the passenger compartment. The first and second images may be the same size or different sizes. However, the images may be more or less distorted depending on the distance of the projection system from the first and second locations and the angles of incidence of the light beams at the first and second locations.

[0061] In the embodiments illustrated in Figures 1 and 2, two images are projected onto two surfaces 61 and 62. However, regardless of the embodiment or variant, more than two images could be projected simultaneously in different locations, for example, three, four, or five images. To achieve this, semi-reflective devices must be added to the systems described above.

[0062] Regardless of the embodiment or variant, the semi-reflective device can reflect between 30% and 70% of the radiation from the light beam emitted by the light source 2, irrespective of the wavelength of the light beam. If the transmitted and reflected radiations are of different intensities, it is possible to display: - two (or more) images with different intensities, or - two (or more) images of different sizes with the same intensity, or - two (or more) images of different sizes with different intensities.

[0063] Alternatively, regardless of the embodiment or variant, the semi-reflective device may: - to reflect totally or almost totally certain wavelengths of the light beam, and - to transmit totally or substantially totally the other wavelengths of the light beam.

[0064] To achieve this, in a particular embodiment, a dichroic plate or filter can be used as a semi-reflective device 4. With such a structure, it is possible to display two different images simultaneously in two different locations. Indeed, the dichroic plate or filter transmits radiation of one or more first wavelengths and reflects radiation of other second wavelengths. It is therefore possible to display: - firstly, a first image composed with radiation from the first wavelengths, and - secondly, a second image composed with the radiation of the second wavelengths. These two images may have different colors and different geometries.

[0065] In another particular embodiment, the semi-reflective device 4 may comprise several selectable or activatable elements (such as a first element and a second element), for example: - a semi-reflective plate exhibiting similar behavior across all wavelengths, and - a dichroic blade or filter as mentioned above. In one operating mode, the first element, such as the semi-reflective plate, may be activated (the second element being deactivated), and in a second operating mode, the second element, such as the dichroic filter, may be activated (the first element being deactivated). The activation and deactivation of the elements can be achieved by moving them so that they either intercept or block the light beam.

[0066] In the preceding description, we mentioned the display of images. However, the generated images can be images that evolve over time; in other words, the solutions described allow not only the display of images but also the display of videos.

[0067] Thanks to the solutions according to the invention, with a single light source and a single scanning device, two images can be displayed simultaneously in two different locations. For example, when the driver of a motor vehicle intends to change direction, they can activate the projection system to display, on the side of the intended change of direction, simultaneously: - on the ground, in front of the motor vehicle, a first image representing, for example, an arrow, and - on the ground, behind the motor vehicle, a second image representing for example an arrow.

[0068] Similarly, for example, when users of the motor vehicle approach the motor vehicle, the projection system can be activated by the motor vehicle in order to display: - a first image of a welcome scenario on the ground at the level of a first door, and - a second welcome scenario image on the ground at the level of a second door.

Claims

Demands

1. Light projection system (1) comprising the following elements: - a light source (2) emitting a light beam, - a scanning device (3), - a semi-reflective device (4), the semi-reflective device (4) being arranged and / or configured so that the light projection system (1) simultaneously produces: - a first image in a first place (61), and - a second image in a second place (62).

2. Light projection system according to claim 1, characterized in that the semi-reflective device is arranged upstream of the scanning device relative to the path of the light beam.

3. Light projection system according to claim 1, characterized in that the semi-reflective device is arranged downstream of the scanning device relative to the path of the light beam.

4. Light projection system according to any one of the preceding claims, characterized in that it comprises at least one optical device (5) for shaping a light beam downstream of the scanning device (3) and the semi-reflecting device (4) relative to the path of the light beam.

5. Light projection system according to any one of claims 1 to 2, characterized in that it comprises at least one optical device (5) for shaping a light beam upstream of the scanning device (3) and downstream of the semi-reflective device (4) relative to the path of the light beam.

6. Light projection system according to any one of the preceding claims, characterized in that the semi-reflective device reflects between 30% and 70% of the radiation of the light beam emitted by the light source (2) regardless of the wavelength of the light beam, and / or in that the semi-reflective device transmits between 30% and 70% of the radiation of the light beam emitted by the light source (2) regardless of the wavelength of the light beam.

7. Light projection system according to any one of claims 1 to 5, characterized in that the semi-reflective device: - totally or substantially totally reflects certain wavelengths of the light beam, and - totally or substantially totally transmits the other wavelengths of the light beam.

8. A method of operating a light projection system according to any one of the preceding claims, the method comprising the following steps: - emission of a light beam, - time-variable deflection of the light beam so as to make it describe a solid angle, - partial reflection of the light beam, so as to produce simultaneously: - a first image in a first place (61), and - a second image in a second place (62).

9. A method according to claim 8, characterized in that the variable deflection step takes place before the partial reflection step.

10. A method according to claim 8, characterized in that the variable deflection step takes place after the partial reflection step.

11. Motor vehicle (100) comprising a light projection system according to any one of claims 1 to 7, and / or comprising hardware and / or software elements (2, 3, 4, 5, 7) implementing the method according to any one of claims 8 to 10, in particular hardware (2, 3, 4, 5, 7) and / or software elements designed to implement the method according to any one of claims 8 to 10.

12. Product computer program comprising program code instructions recorded on a computer-readable medium to carry out the steps of the process according to any one of claims 8 to 10 when said program is run on a computer.

13. Computer-readable data storage medium (7) on which is stored a computer program comprising program code instructions for implementing the method according to any one of claims 8 to 10.

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