Signal lamp generating novel dynamic effects

Abstract

According to the invention, the luminous signalling device (2) comprises a light source (4) that is driven by a control unit (10). A light guide (14) is illuminated by the light source (4). The light guide (12) comprises a chamfer (24) allowing the light beam (8) emitted by the light source to illuminate a region A at least ten times more intensely then a region B illuminated by scattering elements (26) present in the light guide. The regions A and B are present on a front face (20) of the light guide. The control unit (10) is configured to make the light intensity of the light beam (8) emitted by the light source (4) vary so as to create original dynamic effects in the regions A and B.

Description

[0001] The present invention relates to a light signaling device for a motor vehicle, comprising a dynamically illuminated surface light source. Technological background

[0002] Regulations require that every motor vehicle be equipped with flashing lights to indicate the driver's intentions to other road users. Over time, these lights have become a way to personalize vehicles.

[0003] The use of light guides has allowed for greater freedom in the arrangement of lighting devices in automotive headlights, while also significantly reducing their size. For example, the use of flat or nearly flat light guides is known for creating surface light sources. Surface light sources are characterized by a two-dimensional illumination area with a small depth. A continuously evolving lighting module for automobiles, described in document WO2014 / 199108, is also known.

[0004] The invention aims to propose a new type of light signaling device, comprising at least one surface light source, dynamically illuminated so as to obtain original visual effects. Object of the invention

[0005] To this end, the present invention proposes a light signaling device according to the attached claim 1.

[0006] According to one embodiment of the invention, the chamfer and diffusing elements are configured so that an observer on the front face of the light guide, when the light source is activated, perceives a light signal at zone A which is between ten and twenty times more intense than at zone B.

[0007] According to another embodiment of the invention, the control unit is configured to vary the intensity of the light beam according to a relationship comprising an exponential function.

[0008] According to another embodiment of the invention, the diffusion zone is recessed by at least two lateral edges of the light guide. The lateral edges define the contours of the front face of the light guide.

[0009] According to another embodiment of the invention, the control unit is configured to increase the intensity of the light beam during an ignition phase lasting between 0.4s and 0.6s; preferably on the order of 0.5s.

[0010] According to another embodiment of the invention, the control unit is configured to decrease the intensity of the light beam during an extinction phase lasting between 1s and 1.4s; preferably on the order of 1.2s.

[0011] According to another embodiment of the invention, the control unit is configured to maintain constant intensity of the light beam during a usage phase, between an ignition phase and an extinction phase of the light beam, the duration of the usage phase is between 1s and 1.4s; preferably on the order of 1.2s.

[0012] Of course, the different characteristics, variants and forms of realization mentioned above can be associated with each other in various combinations, insofar as they are not incompatible or exclusive of each other.

[0013] The invention also relates to a motor vehicle comprising a light signaling device as described above. Description of the figure

[0014] The following description, in relation to the attached drawing, given by way of non-limiting example, will allow for a better understanding of what the invention consists of and how it can be implemented: [ Fig. 1 ] represents a schematic view of a longitudinal section of a light signaling device according to the invention. Detailed description of an example of implementation

[0015] As a reminder, the invention proposes a new type of light signaling device, comprising at least one surface light source, dynamically illuminated to obtain original visual effects.

[0016] There figure 1 This illustrates a non-limiting embodiment of a light signaling device 2 according to the invention. The light signaling device 2 comprises a light source 4, including one or more light-emitting diodes 6. Preferably, the light source 4 comprises several light-emitting diodes 6 capable of emitting light beams of different colors, so as to form an RGB light source. In this example, the light source is capable of emitting a monochromatic or polychromatic light beam 8.

[0017] The light source 4 is connected to a control unit 10 which controls the operation of each LED 6. The control unit 10 is capable of switching the light beam 8 emitted by each LED on and off and changing its intensity. The control unit can also change the color of the light beam by switching some of the LEDs on or off.

[0018] According to the invention, the control unit 10 is configured to vary the intensity of the light beam 8 emitted by the light source 4, during one or more operating cycles. An operating cycle is divided into three phases: a first phase called ignition, consisting of continuously and non-linearly increasing the intensity of the light beam 8 up to a threshold value; then a second phase called use, consisting of maintaining the intensity of the light beam 8 at the level of the threshold value; then a third phase called extinction, consisting of continuously and non-linearly decreasing the intensity of the light beam 8.

[0019] The duration of an operating cycle is between 1 and 5 seconds, preferably around 2 seconds. During an operating cycle, the ignition phase is between 0.4 and 0.6 seconds, preferably around 0.5 seconds. The operating phase is between 1 and 1.4 seconds, preferably around 1.2 seconds, and the shutdown phase is between 1 and 1.4 seconds, preferably around 1.2 seconds.

[0020] During the ignition phase, the intensity of the light beam 8 varies exponentially.

[0021] During the extinction phase, the intensity of the light beam 8 decreases according to an exponential function, similar to the previous function.

[0022] The light source 4 is arranged to illuminate a lateral face 12 of a light guide 14, located at a proximal end 16 of said guide. The light guide extends in a longitudinal direction (XX') between its proximal end 16 and a distal end 18. The proximal and distal ends are separated by a distance of between 20 mm and 200 mm, preferably between 100 mm and 150 mm.

[0023] The light guide 14 is delimited by a front face 20 parallel or substantially parallel to a rear face 22. The front and rear faces are separated by a distance of between 3 mm and 10 mm, preferably between 4 mm and 5 mm.

[0024] The light guide 14 is configured to allow the propagation of part of the light beam 8 emitted by the light source 4, from its proximal end 16 to its distal end 18. The front and rear faces are two- or three-dimensional, so as to form a surface light source 4, when the light source 4 is lit.

[0025] According to this example, the light guide 14 is characterized by a rectangular or substantially rectangular cross-section. Preferably, the light guide 14 is transparent or crystalline in appearance. It can, for example, be made from one of the following materials: polymethyl methacrylate (PMMA) and / or polycarbonate (PC).

[0026] At its distal end 18, the light guide 14 has a lateral face inclined to form a chamfer 24. The chamfer 24 is configured to reflect a portion of the light beam 8' towards a zone A on the front face 20 of the light guide. Zone A is located at least partially opposite the chamfer 24. Zone A can extend along the longitudinal direction (XX') of the light guide, over a distance D of between 2 mm and 8 mm, preferably between 3 mm and 6 mm. Preferably, the chamfer 24 is a flat surface, forming an acute angle with the front face 20 of the light guide, with a value of approximately 45°. The chamfer has undergone a surface treatment to increase its reflectance of the light emitted by the light source 4.

[0027] The light guide 14 includes diffusing elements located between its proximal end 16 and the chamfer 24. The diffusing elements are configured to diffuse a portion of the light beam 8" towards the front face 20 of the light guide. In this example, the diffusing elements are formed by cavities 26 open on the rear face 22 of the light guide. In this example, the cavities 26 are arranged so that their density gradually increases between the proximal end 16 and the chamfer 24, opposite a zone B located at the front face 20, so that the brightness of the front face 20 is homogeneous or substantially homogeneous for an observer looking at zone B when the light source 4 is activated. The internal volume of each cavity 26 is between 48,000 µm³ and 536,000 µm³, preferably on the order of 95 000 µm 3< and 268,000 µm 3<, preferably on the order of 218,000 µm 3<.The cavities 26 are spaced apart by a distance of between 0.12 mm and 0.7 mm, preferably between 0.13 mm and 0.5 mm.

[0028] According to the invention, the diffusing elements and the chamfer 24 are configured so that an observer perceives a light signal ten times more intense at zone A, compared to the same light signal perceived at zone B, when the light source 4 is switched on. Preferably, the light intensity perceived at zone A is more than ten times the light intensity perceived at zone B, preferably between ten and twenty times.

[0029] Surprisingly, the synergy between the light source 4 and the light guide 14 creates an unexpected dynamic visual effect for an observer viewing the front face 20 of the light guide during an operating cycle of the light source 4 controlled by the control unit 10. More specifically, during the start-up phase, the observer has the visual sensation that zone A illuminates more quickly than zone B, and during the switch-off phase, zone A appears to switch off more quickly than zone B. In other words, thanks to the invention, it is possible to create at least two zones on the front face 20 of the light guide, perceived by an observer as switching on and off at different speeds, using a single light source 4 simultaneously illuminating zones A and B.Advantageously, dynamic visual effects are obtained during the switching on and off phases of the signaling device, using a single light source 4, which reduces the manufacturing costs of said device.

Claims

1. Luminous signaling device (2) for motor vehicle comprising a light source (4) controlled by a control unit (10), the light source (4) being designed such that its light beam (8) can lighten a proximal end (16) of a light guide (14) and propagate inside the light guide between a front face (20), parallel or essentially parallel to a rear face (22) of the light guide (14), and the rear face, the light guide (14) comprising a chamfer (24) at the level of a distal end (18), the chamfer (24) being oriented such as to reflect a part (8') of the light beam that propagates inside the light guide (14), towards a zone A located at the level of its front face (20), the light guide (14) also comprising diffusing elements (26) located between its proximal end (16) and the chamfer (24), the diffusing elements (26) being configured such as to diffuse a part (8") of the light beam towards a zone B located at the level of the front face (20), the Luminous signaling device (2) being characterized in that the chamfer (24) and the diffusing elements (26) are configured in a way that an observer of the front face (20) of the light guide (14), when the light source (4) is activated, sees a light signal at the level of the zone A that is at least ten times more intense than at the level of the zone B, in that the control unit (10) is configured such as to vary continuously and progressively the intensity of the light beam (8) sent out by the light source (4) during a switch-on phase and / or a switch-off phase of the light source (4), and in that the chamfer (24) has undergone a surface treatment such as to increase its coefficient of reflection of the light sent out by the light source (4).

2. Luminous signaling device (2) according to claim 1, characterized in that the chamfer (24) and the diffusing elements (26) are configured in a way that an observer of the front face (20) of the light guide (14), when the light source (4) is activated, sees a light signal at the level of the zone A that is between ten times and twenty times more intense than at the level of the zone B.

3. Luminous signaling device (2) according to claim 1 or 2, characterized in that the control unit (10) is configured such as to vary the intensity of the light beam (8) according to a relation comprising an exponential function.

4. Luminous signaling device (2) according to one of claims 1 to 3, characterized in that the zone B is retracted by at least two side edges of the light guide (14).

5. Luminous signaling device (2) according to one of claims 1 to 4, characterized in that the control unit (10) is configured for increasing the intensity of the light beam (8) during a switch-on phase which lasts between 0.4 sec and 0.6 sec.

6. Luminous signaling device (2) according to one of claims 1 to 5, characterized in that the control unit (10) is configured for decreasing the intensity of the light beam (8) during a switch-off phase which lasts between 1 sec and 1.4 sec.

7. Luminous signaling device (2) according to one of claims 1 to 6, characterized in that the control unit (10) is configured for maintaining the intensity of the light beam (8) constant during an operating phase, between a switch-on phase and a switch-off phase of the light beam (8), the operating phase lasting between 1 sec and 1.4 sec.

8. Motor vehicle comprising a luminous signaling device (2) according to one of claims 1 to 7.

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