MULTI-PART LIGHTING DEVICE FOR A MOTOR VEHICLE

Abstract

The invention proposes a multi-part lighting device for a vehicle that limits production costs and the risk of parasitic electromagnetic interference. The invention notably makes it possible to produce complex optical signatures by limiting the connections between different parts of the same device, while allowing the provision of light animations and diagnostic functions. (Fig. 4))

Description

Title of the invention: MULTI-PART LIGHTING DEVICE FOR A MOTOR VEHICLE

[0001] This invention relates to the field of motor vehicle lighting, and in particular it relates to a two-part signaling light device, such as, for example, a direction indicator.

[0002] A light-emitting diode, LED, is a semiconductor electronic component capable of emitting light of a predetermined wavelength when an electrical voltage at least equal to a threshold value is applied to its terminals. Beyond this threshold value, called forward voltage, the intensity of the luminous flux emitted by an LED generally increases proportionally with the average intensity of the supply electric current. Their small size and low power consumption make LED components interesting in the field of light modules for motor vehicles. LED-type light sources can, for example, be used to produce distinctive optical signatures by placing the components along predetermined contours. The distinctive optical signatures can, in particular, extend over several parts of the chassis of a motor vehicle.Thus, for example, it has been proposed to produce a direction indicator light in two parts: one part being arranged on a rear wing of the motor vehicle, and another adjacent part being arranged on the trunk door of the motor vehicle.

[0003] The provision of a lighting device performing a single regulatory lighting function on separate parts of a vehicle chassis generally results in a multiplication of wiring between vehicle control modules, power supply modules, microcontrollers or control devices on the one hand and the different parts of the lighting device on the other hand.

[0004] This situation is generally further accentuated if the light functions provided on separate parts of the vehicle also provide animated signals. However, animated light signals such as a dynamic direction indicator increase road safety, since moving light signals are more quickly perceived by the human visual system.

[0005] Each additional wired connection generates increased production costs and an increased risk of capturing parasitic electromagnetic radiation which can negatively influence the operation of the device by generating interference on other useful signals.

[0006] The invention aims to overcome at least one of the problems posed by the art More specifically, the invention aims to propose a multi-part light device which limits production costs and the risk of parasitic electromagnetic interference.

[0007] According to a first aspect of the invention, a lighting device for a motor vehicle is proposed. The device comprises a plurality of light source branches distributed among a first and a second part of the lighting device, the first and the second part being intended to be installed on a first respectively a second part of the chassis of the motor vehicle, and each comprising at least one control unit configured to selectively control the electrical supply of the elementary light source branches of the corresponding part.The light device is remarkable in that a common power supply branch connects the two parts and in that the at least one driving unit of each part is intended to be controlled by sequentially shifted control signals using delays generated by a respective delay unit, so that all light source branches of the device perform sequential light animation.

[0008] The light device may preferably comprise a diagnostic coupling unit connected to a switch and to a circuit for measuring the intensity of the electric current which supplies the second part, configured on the one hand to cut off the electric power supply to the second part by means of the switch if the control unit of the first part detects a fault in a light source, and on the other hand to cut off the power supply to the first part if the measurement circuit indicates an electric current intensity lower than a predetermined threshold value when the second part is supplied.

[0009] According to a second aspect of the invention, a lighting device for a motor vehicle comprising a plurality of branches of light sources distributed among a first and a second part of the lighting device is proposed, the first and the second part being intended to be installed on a first respectively a second part of the chassis of the motor vehicle, and each comprising at least one control unit configured to selectively control the electrical supply of the branches of elementary light sources of the corresponding part.The lighting device is remarkable in that a common electrical supply branch connects the two parts and in that the lighting device comprises a diagnostic coupling unit connected to a switch and to a circuit for measuring the intensity of the electrical current which supplies the second part, configured on the one hand to cut off the electrical supply to the second part by means of the switch if the control unit of the first part detects a fault in a light source, and on the other hand to cut off the power supply to the first part if the measuring circuit. indicates an electric current intensity below a predetermined threshold value when the second part is powered.

[0010] The at least one driving unit of each part may preferably be intended to be controlled by sequentially shifted control signals using delays generated by a respective delay unit, so that all light source branches of the device perform sequential light animation.

[0011] Preferably, the delay unit of each part can be implemented by means of a shift register circuit.

[0012] The delays of all the control signals generated by the delay unit of the first part may preferably be longer than the delay of the most delayed control signal generated by the delay unit of the second part.

[0013] Preferably, the common electrical supply branch may be intended to provide a cyclic binary supply signal, each cycle comprising an off phase and an on phase of the device and in which the shifts of the control signals are such that all the branches are sequentially supplied with electricity during the duration of an on phase.

[0014] Preferably, the diagnostic coupling unit, the switch and the measuring circuit can be an integral part of the first part of the lighting device. This allows better integration of the components in the lighting device, making it more compact.

[0015] The switch may preferably be located on the common power supply branch, between the first part and the second part of the lighting device.

[0016] Alternatively, the switch may be located on the common power supply branch, upstream of the first and second parts of the lighting device.

[0017] The coupling diagnostic unit may preferably be configured to cut off the power supply to both parts by means of the switch if the measuring circuit indicates an electric current intensity below a predetermined threshold value.

[0018] Preferably, the coupling diagnostic unit can be configured to put the control unit of the first part into fault if the measuring circuit indicates an electric current intensity lower than a predetermined threshold value.

[0019] According to a third aspect of the invention, a motor vehicle is provided. The vehicle is remarkable in that it comprises a light device for producing an animated direction indicator signal, the light device being in accordance with one aspect of the invention, the first part of the device being installed on a rear wing and the second part of the light device being installed on the trunk door of the motor vehicle.

[0020] According to a third aspect of the invention, a motor vehicle comprising is provided. The motor vehicle is remarkable in that it comprises a lighting device according to one aspect of the invention, the first part of the device being installed on a rear wing and the second part of the lighting device being installed on the trunk door of the motor vehicle.

[0021] By using the measures proposed by the present invention, it becomes possible to produce a multi-part lighting device which limits production costs and the risk of parasitic electromagnetic interference. Indeed, the two parts of the proposed lighting device are powered by a single power supply line. According to preferred embodiments, sequential animations can be achieved without adding other control units, using only delay circuits synchronized with each other. According to other embodiments, a fault diagnosis in one of the parts automatically causes the entire lighting device to be switched off, thus complying with the electrical regulations in force. This functionality is also achieved without providing additional and dedicated connections between the two parts of the device, thus limiting production costs as well as the risks of interference.The use of the device is particularly interesting for the production of a dynamic direction indicator signal light distributed on a rear wing and a trunk door of a motor vehicle.

[0022] Other characteristics and advantages of the present invention will be better understood with the aid of the description of the examples and the drawings among which:

[0023] - [Fig.l] shows schematically a device in accordance with a mode of preferred embodiment of the invention;

[0024] - [Fig.2] shows schematically a device in accordance with a mode of preferred embodiment of the invention;

[0025] - [Fig.3] shows schematically a device in accordance with a mode of preferred embodiment of the invention;

[0026] - [Fig.4] shows schematically a device in accordance with a mode of preferred embodiment of the invention;

[0027] - [Fig.5] shows schematically a part of the rear view of a vehicle automobile in accordance with a preferred embodiment of the invention.

[0028] Unless specifically indicated otherwise, technical features described in detail for a given embodiment may be combined with the technical features described in the context of other embodiments described by way of example and in a non-limiting manner. Similar reference numerals will be used to describe similar concepts across different embodiments of the invention. For example, references 100, 200, 300 and 400 designate three embodiments for producing a light device according to the invention.

[0029] The illustration of [Fig.l] shows a lighting device 100 for a motor vehicle. The device 100 comprises a plurality of branches 121, 122, 123, 131, 132, 133 of light sources. Preferably these are light-emitting diodes. While the illustration comprises three branches with two light-emitting diodes, this example is not limiting of the invention and different pluralities of branches and light-emitting diodes per branch can be used without departing from the scope of the invention. Three branches 121, 122, 123 are part of a first part 120 of the lighting device, while three additional branches 131, 132, 133 are part of a second part 130 of the device. The two parts 120, 130 are physically distinct and connected by a common power supply branch 110.Thus, the electrical circuits forming the first and second parts are implanted on physically distinct PCB substrates ("printed circuit board") and electrically connected to each other. Each of the two parts of the device is intended to be installed on a distinct part of a motor vehicle, such as on a rear wing and a trunk door, for example. Each of the two parts of the device comprises a control unit 124, 134 configured to selectively control the electrical supply of the branches connected thereto. These are preferably linear control units, capable of providing a constant level of electrical current to each of the branches. Depending on the number of branches, the number of control units can be increased to accommodate all the branches without departing from the scope of the present invention.

[0030] The control unit(s) of each part 120, 130 is intended to be controlled by control signals sequentially shifted using delays generated by a delay unit 125, 135 preferably produced by an electronic circuit known in the art for providing a shift register and a clock signal. Each of the signals 126, 127, 128 generated by the delay unit 125 is thus intended to delay by a predetermined period of time the switching on of one of the branches 121, 122, 123 of the first part 120 of the device. Each of the signals 136, 137, 138 generated by the delay unit 135 is intended to delay by a predetermined period of time the ignition of one of the branches 131, 132, 133 of the second part 120 of the device.

[0031] The two delay units 125 and 135 are synchronized and operate as soon as a power supply signal is available on the common power supply branch 110. Thus, according to a preferred embodiment, all the control signals generated by the delay unit 125 of the first part are longer than the delay of the most delayed control signal generated by the delay unit 135 of the second part. According to this configuration it becomes possible to realize a dynamic sequence according to which, by referencing [Fig.l], the branches 133, 132, 132 light up first from right to left, then only the branches 123, 122, 121 of the first part 120 also light up. The lighting device of [Fig.l] is intended to be mounted at the rear of the vehicle, on the left side. Thus, in [Fig.l], an animation from right to left corresponds to an animation starting for example from a second part of the device intended to be installed on a trunk door of the vehicle, towards a first part of the device intended to be installed on a wing of the vehicle.Symmetrically, in a lighting device according to the invention intended to be mounted at the rear of the vehicle, on the right side, an animation starting from a second part of the device intended to be installed on the trunk door of the vehicle towards a first part of the device intended to be installed on a wing of the vehicle would correspond to an animation from left to right.

[0032] The power supply signal of the device is generally supplied by a central control unit of the motor vehicle on the common power supply branch 110. To produce a direction indicator, this power supply signal is preferably binary, alternating lit phases with unlit phases. The rising edge of such a signal marks the start of the electrical supply of the two delay units 124 and 134. All the delays generated can then preferably be chosen so that a scrolling from right to left of all the branches is carried out before the power supply signal goes to a low or zero level. At this moment, no more electrical supply will be supplied to the two parts 120, 130 of the device, until the next rising edge of the signal supplied by the branch 110.

[0033] The illustration of [Fig.2] shows a lighting device 200 for a motor vehicle. The device 200 comprises a plurality of branches 221, 222, 223, 231, 232, 233 of light sources. In the non-limiting example shown, three branches 221, 222, 223 are part of a first part 220 of the lighting device, while three additional branches 231, 232, 233 are part of a second part 230 of the device. The two parts 220, 230 are physically distinct and electrically connected to each other. Each of the two parts of the device comprises a linear control unit 224, 234 configured to selectively control the power supply of the branches connected thereto.

[0034] The lighting device 200 further comprises a diagnostic coupling unit 240, which makes it possible to relay detected errors from the first part 220 to the second part 230 and vice versa. In the example of [Fig. 2], the diagnostic coupling unit 240 is connected to a switch 252 which is located on the power supply branch 210 between the first and second parts. When no fault is detected and the power supply signal provided on the branch 210 indicates that the device 200 has been switched on, this switch remains closed. The switch is preferably made by a circuit using a transistor. The diagnostic coupling unit 240 is also connected to an electrical circuit 250 making it possible to measure the intensity of the electric current which flows in the second part 230 of the device while the device is switched on.

[0035] In a known manner, a control unit 224, 234 comprises diagnostic means for detecting faults in the controlled light-emitting diodes. Upon detection of a fault, a diagnostic signal is provided and all the controlled diodes are switched off.

[0036] The coupling diagnostic unit 240 is produced by an electronic circuit which makes it possible to automatically cut off 253 the electrical power supply to the second part 230 by opening the switch 252 if the control unit 224 of the first part 220 detects a fault or a failure at the level of one of the light sources of one of the branches 221, 222, 223.

[0037] Similarly, when the control unit 234 of the second part 230 detects a fault or a failure at one of the light sources of one of the branches 231, 232, 233, all the controlled diodes in question will be switched off. This causes a drop in the electric current intensity 251 measured by the measuring circuit 250. Thus, by comparing this measurement 251 to a threshold value by means of a comparator circuit known in the art, the diagnostic unit is capable of notifying the control unit 224 of the first part 220 of the device of the fault detected at the second part. Typically the threshold value is 10 mA. Below this value, the unit 240 concludes that there is a fault at the level of the second part 230. In the example of [Fig.2], the notification 243 provided to the control unit 224 causes this control unit 224 to go into fault. As a consequence, the branches 212, 222, 223 of the first part will also be switched off.

[0038] The illustration of [Fig. 3] shows an alternative embodiment of the device 300 for a motor vehicle. As for the previous embodiment, the device 300 comprises a plurality of branches 321, 322, 323, 331, 332, 333 of light sources. Each of the two parts of the device 320, 330 comprises a linear control unit 324, 334 with a diagnostic system, configured to selectively control the power supply of the branches connected thereto.

[0039] The lighting device 300 further comprises a coupling diagnostic unit 340, which makes it possible to relay detected errors from the first part 320 to the second part 330 and vice versa. In the example of [Fig. 3], the coupling diagnostic unit 340 is connected to a switch 352 which is located on the power supply branch 310 upstream of the two parts 320 and 330. When no fault is detected and the power supply signal supplied on the branch 310 indicates that the device 300 has been switched on, this switch remains closed. The switch is preferably made by a circuit using a transistor. The diagnostic coupling unit 340 is also connected to an electrical circuit 350 making it possible to measure the intensity of the electric current which flows in the second part 330 of the device while the device is switched on.

[0040] The coupling diagnostic unit 340 is produced by an electronic circuit which makes it possible to automatically cut off 353 the electrical power supply to the second (and first) part 330 by opening the switch 352 if the control unit 324 of the first part 320 detects a fault or a failure at the level of one of the light sources of one of the branches 321, 322, 323.

[0041] Similarly, when the control unit 334 of the second part 330 detects a fault or a failure at the level of one of the light sources of one of the branches 331, 332, 333, all the controlled diodes in question will be switched off. This causes a drop in the electric current intensity 351 measured by the measuring circuit 350. Thus, by comparing this measurement 351 to a threshold value by means of a comparator circuit known in the art, the diagnostic unit is capable of cutting off 353 the electrical power supply to the two parts by means of the switch 352.

[0042] The illustration in [Fig. 4] shows an embodiment of the lighting device 400 according to the invention which combines the characteristics of [Fig. 1] and 3 respectively. The characteristics of Figures 1 and 2 may also be combined in an embodiment in which an alternative placement of the switch is proposed, without departing from the scope of the present invention.

[0043] As for the previous embodiment, the device 400 comprises a plurality of branches 421, 422, 423, 431, 432, 433 of light sources. Each of the two parts of the device 420, 430 comprises a linear control unit 424, 434 with a diagnostic system, configured to selectively control the power supply of the branches connected thereto.

[0044] The lighting device 400 further comprises a coupling diagnostic unit 440, which makes it possible to relay detected errors from the first part 420 to the second part 430 and vice versa. In the example of [Fig. 4], the coupling diagnostic unit 440 is connected to a switch 452 which is located on the power supply branch 410 upstream of the two parts 420 and 430. When no fault is detected and the power supply signal supplied on the branch 410 indicates that the device 400 is switched on, this switch remains closed. The switch is preferably implemented by a circuit using a transistor. The coupling diagnostic unit 440 is also connected to an electrical circuit 450 making it possible to measure the intensity of the electric current flowing in the second part 430 of the device while the device is switched on.

[0045] The diagnostic coupling unit 440 is implemented by an electronic circuit which allows 453 to automatically cut off the power supply to the second (and first) part 430 by opening the switch 452 if the control unit 424 of the first part 420 detects a fault or failure in one of the light sources of one of the branches 421, 422, 423.

[0046] Similarly, when the control unit 434 of the second part 430 detects a fault or a failure at the level of one of the light sources of one of the branches 431, 432, 433, all the controlled diodes in question will be switched off. This causes a drop in the electric current intensity 451 measured by the measuring circuit 450. Thus, by comparing this measurement 451 to a threshold value by means of a comparator circuit known in the art, the diagnostic unit is capable of cutting off 453 the electrical power supply to the two parts by means of the switch 452.

[0047] The control unit 424, 434 of each part 420, 430 is further intended to be controlled by control signals sequentially shifted using delays generated by a delay unit 425, 435 preferably produced by an electronic circuit known in the art for providing a shift register. Each of the signals 426, 427, 428 generated by the delay unit 425 is thus intended to delay by a predetermined period of time the ignition of one of the branches 421, 422, 423 of the first part 420 of the device. Each of the signals 436, 437, 438 generated by the delay unit 435 is intended to delay by a predetermined period of time the ignition of one of the branches 431, 432, 433 of the second part 420 of the device.

[0048] The two delay units 425 and 435 are synchronized and operate as soon as a power supply signal is available on the common power supply branch 410. Thus, according to a preferred embodiment, all the control signals generated by the delay unit 425 of the first part are longer than the delay of the most delayed control signal generated by the delay unit 435 of the second part. According to this configuration it becomes possible to produce a dynamic sequence according to which, by referencing [Fig. 4], the branches 433, 432, 431 first light up from right to left, then only the branches 323, 322, 321 of the first part 120 also light up sequentially. Other sequencings are obviously conceivable without departing from the scope of the present invention.

[0049] The power supply signal of the device is generally supplied by a central control unit of the motor vehicle on the common power supply branch 410. To produce a direction indicator, this power supply signal is preferably binary, alternating lit phases with unlit phases. The rising edge of such a signal marks the start of the electrical supply of the two delay units 424 and 434. All the delays generated can then preferably be chosen so that a scrolling from right to left of all the branches is carried out. before the power supply signal goes low or to zero. At this time, no more power will be supplied to the two parts 420, 430 of the device, until the next rising edge of the signal supplied by branch 410.

[0050] The illustration of [Fig.5] shows the placement of the two respective parts of a device 100, 200, 300, 400 according to one of the preceding embodiments on the wing 12 respectively the trunk door 14 of a motor vehicle 10.

[0051] The scope of protection is determined by the claims.

Claims

Claims

1. Lighting device (200, 300, 400) for a motor vehicle comprising a plurality of branches (221, 222, 223, 231, 232, 233) of light sources distributed among a first (220, 320, 420) and a second part (230, 330, 430) of the lighting device, the first and the second part being intended to be installed on a first respectively a second part of the chassis of the motor vehicle, and each comprising at least one control unit (224, 234; 324, 334; 424, 434) configured to selectively control the electrical supply of the elementary light source branches of the corresponding part, characterized in that a common electrical supply branch (210, 310, 410) connects the two parts and in that the lighting device comprises a diagnostic coupling unit (240, 340, 440) connected to a switch (252, 352, 452) and to a measuring circuit (250, 350,450) of the intensity of the electric current which supplies the second part (230, 330, 430), configured on the one hand to cut off (253, 353, 453) the electric power supply of the second part (230, 330, 430) by means of the switch (252, 352, 452) if the control unit (224, 324, 424) of the first part (220, 320, 420) detects a fault (243, 343, 443) of a light source, and on the other hand to cut off (241, 341, 441) the power supply of the first part (220, 320, 420) if the measuring circuit (250, 250, 350) indicates an electric current intensity (251, 351, 451) less than a predetermined threshold value when the second part (230, 330, 430) is supplied.,

2. Lighting device according to the preceding claim, characterized in that the diagnostic coupling unit (240, 340, 440), the switch (252, 352, 452) and the measuring circuit (250, 350, 450) form an integral part of the first part (220, 320, 420) of the lighting device.

3. Lighting device (200) according to one of the preceding claims, characterized in that the switch (252) is located on the common electrical supply branch (210), between the first part (220) and the second part (230) of the lighting device.

4. Lighting device according to one of claims 1 or 2, characterized in that the switch (352, 452) is located on the common electrical supply branch (310, 410), upstream of the first (320, 420) and the second part (330, 430) of the lighting device.

5. Lighting device according to the preceding claim, characterized in that the diagnostic coupling unit (340, 440) is configured to cut off (341, 441) the electrical supply of the two parts (320, 420; 330, 430) by means of the switch (352, 452) if the measuring circuit (350, 450) indicates an electrical current intensity (351, 451) lower than a predetermined threshold value.

6. Lighting device according to one of claims 1 to 4, characterized in that the diagnostic coupling unit is configured to put the control unit of the first part into fault if the measuring circuit indicates an electric current intensity lower than a predetermined threshold value.

7. Lighting device (400) according to one of the preceding claims, characterized in that the at least one control unit (424, 434) of each part (420, 430) is intended to be controlled by control signals (426, 427, 428, 436, 437, 438) sequentially shifted using delays generated by a respective delay unit (425, 435), so that all branches (412, 422, 423, 431, 432, 433) of light sources of the device perform sequential light animation.

8. A lighting device according to claim 7, characterized in that the delays of all the control signals (426, 427, 428) generated by the delay unit (425) of the first part (420) are longer than the delay of the most delayed control signal generated by the delay unit (435) of the second part (430).

9. Lighting device according to one of claims 7 to 8, characterized in that the common electrical supply branch (410) is intended to provide a cyclic binary supply signal, each cycle comprising an off phase and an on phase of the device and in which the offsets of the control signals (426, 427, 428, 436, 437, 438) are such that all the branches (412, 422, 423, 431, 432, 433) are sequentially supplied with electricity during the duration of an on phase.

10. Motor vehicle (10) comprising a lighting device (200, 300, 400), characterized in that the lighting device is according to any one of the preceding claims, the first part (220, 320, 420) of the device being installed on a rear wing (12) and the second part (230, 330, 430) of the lighting device being installed on the trunk door (14) of the motor vehicle.

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