Luminous device with several types of light sources

Abstract

Luminous device (100) for a motor vehicle comprising: - two arrangements of semiconductor element light sources (110, 120), each of the light sources comprising a cathode and an anode, said arrangements forming a plurality of light source branches, each of the branches comprising an anode, a cathode and a plurality of serially mounted light sources, the cathode of the branch being formed by the cathode of a light source, said cathode being located at one end of the branch, the anode of the branch being formed by the anode of a light source, said anode being located at the other end of the branch, - each light source of any given light source arrangement being of a same type, the type of the light sources in any given light source arrangement being distinct from the type of the light sources in any given other light source arrangement, such that each type of light source is designed to contribute to a distinct regulatory luminous function, - two power supply lines (112, 122), each power supply line connecting the anodes of the respective branches of one light source arrangement (110, 120); - a power supply control unit (140) having a plurality of terminals (142), each terminal being connected to the cathodes of light source branches (110, 120) of a light source group (130), wherein each light source group comprises a semiconductor element light source branch of each type (110, 120); - a control unit (150), which, on the basis of an lighting instruction (160) received for one of said regulatory light functions, generates a control signal (170) which causes one of the supply lines (112, 122) which connects the anodes of the branches of the corresponding arrangement of light sources (110, 120) to be supplied with electricity at the exclusion of other supply lines.

Description

DescriptionTitle: LUMINOUS DEVICE WITH SEVERAL TYPES OF LIGHT SOURCES

[0001] This invention is related to the field of motor vehicle lighting, and in particular it concerns a luminous signalling device.

[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. Above this threshold value, known as the forward voltage, the intensity of the luminous flux emitted by an LED generally increases proportionally with the average intensity of the electrical supply current. Their small size and low power consumption make LED components particularly attractive for automotive light modules. LED light sources can be used, for example, to create distinctive optical signatures by placing components along predetermined contours.

[0003] Typically, when several light colours are required, for example to perform different regulatory functions, the number of control circuits and / or power supply control circuits is multiplied by the number of light source types required. Each type of light source is controlled by a dedicated module, which results in significant additional costs, as well as taking up a lot of space in the limited space available to create a luminous device for a motor vehicle.

[0004] The aim of the invention is to overcome at least one of the problems posed by the prior art. In particular, the invention aims to provide a luminous device and a method for powering a plurality of different types of light source, using a single control unit.

[0005] According to a first aspect of the invention, a luminous device for a motor vehicle is proposed. The luminous device comprises : two arrangements of semiconductor element light sources, each of the light sources comprising a cathode and an anode, said arrangements forming a plurality of light source branches, each of the branches comprising an anode, a cathode and a plurality of serially mounted light sources, the cathode of the branch being formed by the cathode of a light source, said cathode being located at one end of the branch, the anode of the branch being formed by the anode of a light source, said anode being located at the other end of the branch, each light source of any given light source arrangement being of a same type, the type of the light sources in any given light source arrangement being distinct from the type of the light sources in any given other light source arrangement, such that each type of light source is designed to contribute to a distinct regulatory luminous function,two power supply lines, each power supply line connecting the anodes of the respective branches of one light source arrangement; a power supply control unit having a plurality of terminals, each terminal being connected to the cathodes of light source branches of a light source group, wherein each light source group comprises a semiconductor element light source branch of each type; a control unit, which, based on a lighting instruction received for one of said regulatory light functions, generates a control signal, which causes one of the supply lines which connects the anodes of the branches of the corresponding arrangement of light sources to be provided with electricity at the exclusion of other supply lines of the luminous device.

[0006] Semiconductor element light sources are often mounted in branches, i.e. in a plurality of serially connected light sources, preferentially in a single string comprising no light sources mounted in parallel, as such parallel-mounted light sources represent a cost and may provide poor homogeneity regarding of colour and brightness. Branches may also include other components such as resistors, but, for the sake of energy efficiency, it is preferred that they do not.

[0007] In the invention, only light sources of a same type are mounted in branches in a same arrangement. However, as the light sources of a given arrangements are purposed to provide light specifically for contributing to a given regulatory luminous function, the light sources of another arrangement are of a different type, allowing to provide light for contributing to a distinct regulatory luminous function.

[0008] A plurality of branches is advantageous as it allows for animations of the luminous device, for instance. Specifically, when the supply lines are provided in electricity by battery power regulated through a step-down converter, such as a Buck converter, it is advantageous that the branches consist in serial assemblies of two or three light sources. Indeed, this avoids flickering when the battery voltage is transiently low, for instance at the vehicle start-up. Branches comprising higher numbers of serially connected light sources may be used. A non-step-down type of converter may accordingly be used, It is usually preferred that all branches have a similar number of serially connected light sources.

[0009] It is to be understood that, when a supply line is provided electricity at the exclusion of the other supply lines, any other supply line in the luminous device is not powered, which means that the branches of the corresponding arrangement are not powered. In other words, only one of the supply lines is powered at a given time. This is a requirement for the use of current-sink-type power supply control units.

[0010] Preferably, the power supply control unit can implement said control unit and comprises an input terminal for receiving lighting instructions on a motorvehicle data bus and a control terminal connected to a circuit for selectively interrupting the power supply to each of the two supply lines.

[0011] The control unit can preferably be separate from the power supply control unit.

[0012] Preferably, the control unit can be connected to a selector circuit for connecting a motor vehicle power source selectively to one of the supply lines.

[0013] Preferably, the control unit can be configured to selectively alternate the power supply between the two supply lines.

[0014] Preferably, a first type of semiconductor element light source can be designed to emit amber-coloured light, and a second type of semiconductor element light source can be designed to emit turquoise-coloured light.

[0015] In accordance with a second aspect of the invention, a method for supplying power to two arrangements of semiconductor element light sources of a luminous device for a motor vehicle according to one aspect of the invention is proposed. The method is remarkable in that it comprises the following steps:- the control unit of the luminous device receives a switching command for a regulated luminous function;- the control unit generates a control signal following receipt of said lighting instruction, the control signal causing the supply line corresponding to said regulation light function to be provided with electricity at the exclusion of other supply lines.

[0016] Preferably, the generated control signal can cause the two supply lines to be supplied with electricity exclusively on an alternating basis, at a predetermined alternating frequency.

[0017] The alternating frequency can preferably be at least 200 Hz.

[0018] The light perceived by the alternating power supply between the two types of semiconductor element light sources can preferably be white in colour.

[0019] In an embodiment, the power supply control unit is configured to individually control each of its terminals to selectively power the associated light source group. Preferably, the terminals are controlled so as to regulate the current in the light group, which is connected with this terminal. This individual control capability enables the use of current-sink type drivers having multiple inputs, which can generate sophisticated lighting animations across the branches.

[0020] Such current regulation and animation capabilities are particularly advantageous for implementing welcome scenarios using various combinations of light sources, including white, cyan, red, and / or amber light sources. Furthermore, the individual branch control enables dynamic lighting effects suchas sweeping turn indicator functions, where light sources are activated in sequence to create a directional visual effect.

[0021] The luminous device thus provides enhanced functionality while achieving cost savings through the integration of multiple lighting functions within a single control architecture. By utilizing the power supply control unit's ability to selectively power and regulate different branches, various lighting scenarios can be implemented without requiring additional dedicated control circuits for each function. This consolidation of control functions represents a significant advantage over conventional systems that require separate control units for each lighting function.

[0022] The power supply control unit may comprise a current control input for controlling the current flowing in the associated light group. This current control input allows precise regulation of the luminous intensity of the light sources in each branch independently, thereby enabling fine control of the light output while maintaining the efficiency advantages of the serially-mounted light source configuration. When combined with the selective power supply capabilities previously described, this current control feature further enhances the ability to create sophisticated lighting effects and ensures optimal operation of the different types of light sources within their respective operating parameters.

[0023] The current control input of the power supply control unit may be implemented as either an analog input or a digital input. In the case of an analog input, the current level in the associated branch of the light source arrangement can be continuously varied according to an analog voltage or current signal received at the input.

[0024] Alternatively, when implemented as a digital input, the current control may be achieved through digital communication protocols such as LIN (Local Interconnect Network), CAN (Controller Area Network), or Ethernet. Such digital implementations are particularly advantageous as they allow integration with the vehicle's existing communication infrastructure and enable more sophisticated control schemes. The digital protocols can transmit not only current level commands but also complex animation sequences and timing parameters, thereby expanding the capabilities of the luminous device (100, 200) while maintaining compatibility with modern automotive architectures.

[0025] Using the measures proposed by the present invention, it becomes possible to realize a luminous device luminous device and to propose a method of supplying a plurality of different types of light sources distributed in two arrangements, by means of a single control unit. According to preferred embodiments of the invention, several arrangements of light sources of different types, each type of light source being designed to emit different colours of light, are connected to a single control unit.

[0026] A control unit, which is either a dedicated module or integrated into the control device, is used to selectively power one of the light source arrangement to the exclusion of the others. Compared with existing solutions, this approach makes it possible to reduce the number of printed circuits and control devices used, while at the same time achieving a plurality of regulatory luminous functions by means of the different types of light source. It is also possible to alternate the exclusive supply of two arrangements of light source, so that the light perceived by a human being will be different from the one and other colour emitted by two types of light source, according to the principle of additive synthesis. Depending on the choice of colours, two arrangements of light source can therefore use a single control unit, and generate light beams of at least three different colours, the colour emitted being dependent on the lighting ratio between the arrangements of light sources corresponding to the two types of light source over time.

[0027] Further features and advantages of the present invention will be better understood with the aid of the description of the examples and drawings among which :-Fig. 1 schematically shows a device in accordance with a preferred embodiment of the invention;-Fig. 2 schematically shows a device in accordance with a preferred embodiment of the invention.

[0028] Unless specifically indicated to the contrary, technical features described in detail for a given embodiment may be combined with technical features described in the context of other embodiments described by way of example and in a non-limiting manner. Similar reference numbers will be used to describe similar concepts across different embodiments of the invention. For example, references 100 and 200 refer to two embodiments of a luminous device according to the invention.

Claims

Claims

1. Luminous device (100, 200) for a motor vehicle comprising: two arrangements of semiconductor element light sources (110, 120;210, 220), each of the light sources comprising a cathode and an anode, said arrangements forming a plurality of light source branches, each of the branches comprising an anode, a cathode and a plurality of serially mounted light sources, the cathode of the branch being formed by the cathode of a light source, said cathode being located at one end of the branch, the anode of the branch being formed by the anode of a light source, said anode being located at the other end of the branch, each light source of any given light source arrangement being of a same type, the type of the light sources in any given light source arrangement being distinct from the type of the light sources in any given other light source arrangement, such that each type of light source is designed to contribute to a distinct regulatory luminous function, two power supply lines (112, 122; 212, 222), each power supply line connecting the anodes of the respective branches of one light source arrangement (110, 120; 210, 220); a power supply control unit (140, 240) having a plurality of terminals (142, 242), each terminal being connected to the cathodes of light source branches (110, 120; 210, 220) of a light source group (130, 230), wherein each light source group comprises a semiconductor element light source branch of each type (110, 120; 210, 220); a control unit (150, 250), which, on the basis of an lighting instruction (160, 260) received for one of said regulatory light functions, generates a control signal (170, 270) which causes one of the supply lines (112, 122; 212, 222) which connects the anodes of the branches of the corresponding arrangement of light sources (110, 120; 210, 220) to be supplied with electricity at the exclusion of other supply lines.

2. Luminous device (100) according to the preceding claims, characterized in that the power supply control unit (140) implements said control unit (150) and comprises an input terminal for receiving lighting instructions (160) on a motor vehicle data bus and a control terminal connected to a circuit for selectively interrupting (113, 123) the power supply to each of the two supply lines (112, 122).

3. Luminous device (200) according to claim 1 , characterized in that the control unit (250) is separate from the power supply control unit (240).

4. Luminous device according to the preceding claim, characterized in that the control unit (250) is connected to a selection circuit (213, 223) for connecting a motor vehicle power source selectively to one of the supply lines (212, 222).

5. Luminous device (100, 200) according to one of the preceding claims, characterized in that the control unit (150, 250) is configured to selectively alternate the power supply between the two supply lines (122, 222).

6. Light device (100, 200) according to one of the preceding claims, characterized in that a first type of semiconductor element light sources (110, 210) is designed to emit amber-coloured light and a second type of semiconductor element light sources (120, 220) is designed to emit blue-coloured light.

7. Luminous device (100, 200) according to one of the preceding claims, characterized in that the power supply control unit (140, 240) is configured to individually control each of its terminals (142, 242) to selectively power the associated light source group.

8. Luminous device (100, 200) according to the preceding claim, characterized in that the individual control comprises individual current regulation of each light source group.

9. Luminous device (100, 200) according to the preceding claim, characterized in that the power supply control unit (140, 240) comprises a current control input, the power supply control unit being configured to receive an instruction to selectively power the light source groups on said current control input.

10. A method of supplying power to two types of semiconductor element light sources of a luminous device (100, 200) for a motor vehicle according to one of the preceding claims, the method comprising the following steps:-at the level of the control unit (150, 250) of the luminous device, receive an lighting instruction (160, 260) for a regulation luminous function;-at the control unit (150, 250), generate a control signal (170, 2709) following receipt of said lighting instruction, the control signal causing the supply line corresponding to said regulation light function to be supplied exclusively with electricity.

11. A power supply method according to the preceding claim, characterized in that the control signal generated causes the two supply lines to be supplied with electricity exclusively in alternation, at a predetermined alternation frequency.

12. Power supply method according to the preceding claim, characterized in that the alternating frequency is at least 200 Hz.

13. Power supply method according to the preceding claim, characterized in that the luminous device (100, 200) conforms to claim 6, and in that the light perceived by the alternation of power supply between the two types of semiconductor element light sources has a white colour.

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