Light-emitting devices with several types of light sources

Abstract

A light-emitting device (100) for a motor vehicle includes: - two semiconductor element light source arrangements (110, 120), each of which includes a cathode and an anode, the arrangements forming a plurality of light source branches, each of which includes an anode, a cathode, and a plurality of light sources mounted in series, the cathode of the branch being formed by the cathode of one light source located at one end of the branch, and the anode of the branch being formed by the anode of one light source located at the other end of the branch; - each light source in any given light source arrangement is of the same type, and the type of light source in any given light source arrangement differs from the type of light source in any other given light source arrangement, such that each type of light source is designed to facilitate different regulatory light-emitting functions; - two power supply lines (112, 122), each power supply line connected to the anode of a corresponding branch of a light source arrangement (110, 120); - A power supply control unit (140) having a plurality of terminals (142), each terminal being connected to the cathode of a light source branch (110, 120) of a light source group (130), wherein each light source group includes a light source branch (110, 120) of each type of semiconductor element; a control unit (150) generating a control signal (170) based on a received lighting instruction (160) for one of the regulatory lighting functions, the control signal causing the supply lines (112, 122) that connect to the anode of the branch corresponding to the light source arrangement (110, 120) to be powered, while the other supply lines are not powered.

Description

[0001] This invention relates to the field of motor vehicle lighting, and more specifically, to a light signal device.

[0002] A light-emitting diode (LED) is a semiconductor electronic component that emits light of a predetermined wavelength when a voltage at least equal to a threshold is applied to its terminals. Above this threshold (called the forward voltage), the intensity of the luminous flux emitted by the LED typically increases proportionally to the average intensity of the supply current. The small size and low power consumption of LED components make them particularly attractive for automotive lighting modules. LED light sources can be used to create, for example, unique optical characteristics by placing components along a predetermined contour.

[0003] Typically, when several light colors are required (e.g., to perform different regulatory functions), the number of control circuits and / or power supply control circuits multiplies with the number of light source types required. Each type of light source is controlled by a dedicated module, which results in significant additional costs and occupies a large amount of space in the limited available space for producing light-emitting devices for motor vehicles.

[0004] The purpose of this invention is to overcome at least one problem posed by the prior art. In particular, this invention aims to provide a light-emitting device and a method for powering multiple different types of light sources using a single control unit.

[0005] According to a first aspect of the present invention, a light-emitting device for a motor vehicle is provided. The light-emitting device includes: - An arrangement of two semiconductor element light sources, each of which includes a cathode and an anode, the arrangement forming multiple light source branches, each of which includes an anode, a cathode, and multiple light sources connected in series, the cathode of the branch being formed by the cathode of one light source located at one end of the branch, and the anode of the branch being formed by the anode of one light source located at the other end of the branch. - Every light source in any given light source arrangement is of the same type, and the type of light source in any given light source arrangement differs from the type of light source in any other given light source arrangement, such that each type of light source is designed to facilitate different regulatory light emission functions. - Two power supply lines, each power supply line is connected to the anode of the corresponding branch of a light source arrangement; - Power supply control unit, which has multiple terminals, each terminal being connected to the cathode of the light source branch of the light source group, wherein each light source group includes a light source branch of each type of semiconductor element; - A control unit that generates a control signal based on a received lighting command for one of the regulatory lighting functions, which causes the supply line connecting the anode of the branch corresponding to the light source arrangement to be powered, while the other supply lines of the light-emitting device are not powered.

[0006] Semiconductor element light sources are typically mounted in branches, i.e., multiple light sources connected in series, preferably in a single string excluding light sources mounted in parallel. This is because such parallel light sources increase cost and may provide poorer uniformity in color and brightness. Branches may also include other components, such as resistors, but for energy efficiency, it is preferable that branches do not include other components.

[0007] In this invention, only the same type of light source is installed in the branches of the same arrangement. However, since the light source of a given arrangement is designed to provide light that specifically helps to achieve the light emission function of a given regulation, the light source of another arrangement is of a different type, thereby allowing the provision of light that helps to achieve the light emission function of different regulations.

[0008] Multiple branches are advantageous because they allow for, for example, animated effects of the light-emitting device. Specifically, when the supply line is powered by battery power regulated by a voltage-drop converter (such as a buck converter), it is advantageous for branches to consist of series components of two or three light sources. This effectively avoids flickering when the battery voltage is momentarily low (e.g., during vehicle startup). Branches comprising an even higher number of light sources connected in series can be used. Therefore, non-voltage-drop converters can be used. Generally, it is preferred that all branches have a similar number of light sources connected in series.

[0009] It should be understood that when one supply line is powered while the others are not, none of the other supply lines in the lighting device are powered, meaning that the corresponding branches are not powered. In other words, at any given time, only one supply line is powered. This is a requirement for using a current-absorption type power supply control unit.

[0010] Preferably, the power supply control unit can implement the control unit and includes an input terminal for receiving lighting commands on the vehicle data bus, and a control terminal connected to a circuit for selectively cutting off power to each of the two supply lines.

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

[0012] Preferably, the control unit can be connected to a selection circuit for selectively connecting the vehicle's power supply to one of these supply lines.

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

[0014] Preferably, the first type of semiconductor element light source can be designed to emit amber light, and the second type of semiconductor element light source can be designed to emit cyan light.

[0015] According to a second aspect of the present invention, a method is provided for supplying power to a two semiconductor element light source arrangement of a light-emitting device for a motor vehicle according to one aspect of the present invention. The significant feature of this method is that it includes the following steps: - The control unit of the light-emitting device receives switching commands for the regulated light-emitting function; - Upon receiving the lighting command, the control unit generates a control signal that powers the supply line corresponding to the regulatory lighting function, while de-powering the other supply lines.

[0016] Preferably, the generated control signal enables the exclusive and alternating supply of power to the two supply lines at a predetermined alternating frequency.

[0017] Preferably, the alternation frequency can be at least 200 Hz.

[0018] Preferably, the light perceived by alternating between these two types of semiconductor element light sources can be white.

[0019] In this embodiment, the power supply control unit is configured to individually control each of its terminals to selectively power the associated light source group. Preferably, these terminals are controlled to regulate the current in the lighting group connected to that terminal. This individual control capability enables the use of current-absorbing drivers with multiple inputs, which can generate complex lighting animation effects across branches.

[0020] This ability to regulate current and animate effects is particularly advantageous for achieving popular scenes using various combinations of light sources, including white, cyan, red, and / or amber light sources. Furthermore, individual branch control enables dynamic lighting effects, such as flowing water turn indicators, where light sources are activated sequentially to produce directional visual effects.

[0021] Therefore, the lighting device offers enhanced functionality while achieving cost savings by integrating multiple lighting functions into a single control architecture. Various lighting scenarios can be achieved by utilizing the power supply control unit's ability to selectively power and regulate different branches without requiring additional control circuitry for each function. This consolidation of control functions offers significant advantages over conventional systems that require separate control units for each lighting function.

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

[0023] The current control input of the power supply control unit can be implemented as 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 the analog voltage or current signal received at the input.

[0024] Alternatively, when implemented as a digital input, current control can be achieved via digital communication protocols such as LIN (Linux In-line Networking), CAN (Controller Area Network), or Ethernet. This digital implementation is particularly advantageous because it allows integration with the vehicle's existing communication infrastructure and enables more complex control schemes. Digital protocols can transmit not only current level commands but also complex animation sequences and timing parameters, thereby expanding the capabilities of the lighting devices (100, 200) while maintaining compatibility with modern automotive architectures.

[0025] Using the measures proposed in this invention, a light-emitting device can be realized, and a method is proposed for powering multiple different types of light sources distributed in two arrangements by means of a single control unit. According to a preferred embodiment of the invention, several arrangements of different types of light sources are connected to a single control unit, and each type of light source is designed to emit light of a different color.

[0026] A control unit (either a dedicated module or integrated into a control device) is used to selectively power one of the light source arrangements while excluding the others. Compared to existing solutions, this approach allows for the reduction of the number of printed circuits and control devices used while achieving multiple regulatory light emission functions using different types of light sources. It also allows for the alternating exclusive power supply to two light source arrangements, so that, according to the principle of additive color synthesis, the light perceived by the human will differ from the color emitted by each of the two types of light sources individually. Depending on the color selection, the two light source arrangements can therefore use a single control unit and produce at least three different colors of light beams, the emitted color depending on the brightness ratio between the light source arrangements corresponding to the two types of light sources over time.

[0027] Further features and advantages of the invention will be better understood with the aid of the description of the examples and accompanying drawings, in which: - Figure 1 An apparatus according to a preferred embodiment of the present invention is illustrated schematically; - Figure 2 An apparatus according to a preferred embodiment of the present invention is illustrated schematically.

[0028] Unless explicitly stated otherwise, the technical features described in detail for a given embodiment may be combined with technical features described in the context of other embodiments, which are described by way of example and in a non-limiting manner. Similar reference numerals will be used to describe similar concepts in different embodiments of the invention. For example, reference numerals 100 and 200 refer to two embodiments of the light-emitting device according to the invention.

Claims

1. A light-emitting device (100, 200) for a motor vehicle, the light-emitting device comprising: - A two-semiconductor light source arrangement (110, 120; 210, 220), each light source including a cathode and an anode, the arrangement forming multiple light source branches, each branch including an anode, a cathode, and multiple light sources connected in series, the cathode of a branch being formed by the cathode of one light source located at one end of the branch, and the anode of a branch being formed by the anode of one light source located at the other end of the branch. - Every light source in any given light source arrangement is of the same type, and the type of light source in any given light source arrangement differs from the type of light source in any other given light source arrangement, such that each type of light source is designed to facilitate different regulatory light emission functions. - Two power supply lines (112, 122; 212, 222), each power supply line is connected to the anode of the corresponding branch of a light source arrangement (110, 120; 210, 220); - Power supply control unit (140, 240), the power supply control unit having a plurality of terminals (142, 242), each terminal being connected to the cathode of a light source branch (110, 120; 210, 220) of a light source group (130, 230), wherein each light source group includes a light source branch (110, 120; 210, 220) of each type of semiconductor element. - Control unit (150, 250), which generates control signal (170, 270) based on a received lighting instruction (160, 260) for one of the regulatory lighting functions, the control signal causing the supply line (112, 122; 212, 222) to be powered on the anode of the branch connecting the corresponding light source arrangement (110, 120; 210, 220), while the other supply lines are not powered.

2. The light-emitting device (100) according to the preceding claim, characterized in that, The power supply control unit (140) implements the control unit (150) and includes an input terminal for receiving lighting instructions (160) on a vehicle data bus, and the control terminal is connected to a circuit (113, 123) for selectively cutting off power to each of the two supply lines (112, 122).

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

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

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

6. The lighting device (100, 200) according to any one of the preceding claims, characterized in that, The first type of semiconductor element light source (110, 210) is designed to emit amber light, and the second type of semiconductor element light source (120, 220) is designed to emit blue light.

7. The light-emitting device (100, 200) according to any 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. The light-emitting device (100, 200) according to the preceding claim, characterized in that, The individual control includes individual current adjustment for each light source group.

9. The light-emitting device (100, 200) according to the preceding claim, characterized in that, The power supply control unit (140, 240) includes a current control input terminal, and the power supply control unit is configured to receive instructions at the current control input terminal for selectively supplying power to the light source group.

10. A method for supplying power to two types of semiconductor element light sources for a light-emitting device (100, 200) for a motor vehicle according to any one of the preceding claims, the method comprising the steps of: -At the level of the control unit (150, 250) of the light-emitting device, lighting instructions (160, 260) for the regulated light-emitting function are received. - At the control unit (150, 250), upon receiving the lighting command, a control signal (170, 2709) is generated, which causes power to be exclusively supplied to the supply line corresponding to the regulatory lighting function.

11. The power supply method according to the preceding claim, characterized in that, The generated control signal causes power to be supplied to the two supply lines alternately and exclusively at a predetermined alternating frequency.

12. The power supply method according to the preceding claim, characterized in that, The alternation frequency is at least 200 Hz.

13. The power supply method according to the preceding claim, characterized in that, The light-emitting device (100, 200) conforms to claim 6, and is characterized in that the light perceived by alternating power supply between the two types of semiconductor element light sources is white.

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