Device, circuit for vehicle lighting, LED light emitter, and vehicle

Abstract

There is provided a device for suppressing flicker of an LED element for vehicle lighting during a cold check, the device comprising electronic components in an integrated circuit having a plurality of connectors for electrical connection, the integrated circuit comprising: a VCC connector for inputting a supply voltage; the GND connector is used for outputting power supply voltage; a signal connector for outputting a turn-on signal; a capacitor connector for connecting an external capacitor; a charging circuit that applies a positive voltage to the capacitor connector via the charging resistor when the LED element is turned on from the outside; and an LED switch connected in such a way that, when a predetermined voltage is output on the capacitor connector, it outputs a turn-on signal to the signal connector.

Description

Technical Field

[0001] This utility model relates to a device for suppressing flickering of LED elements in vehicle lighting during cold inspection, a circuit for vehicle lighting, an LED light emitter, and a vehicle. Background Technology

[0002] Typically, vehicles designed for halogen light sources (such as headlights, indicator lights, and brake lights) will have their halogen lamp filaments checked for damage when the vehicle is started or driven. This is known as a "cold check."

[0003] During a cold check, the vehicle's electronic systems apply short voltage pulses, lasting in the millisecond range, to the halogen lamps. If current is detected in the halogen lamp circuit, the filament is intact; otherwise, a warning light on the dashboard alerts the driver to the problem.

[0004] For incandescent lamps, this test pulse is invisible as light because the short voltage pulse is not strong enough to heat the filament. However, if LED lighting is used as an alternative, such as LED retrofit lights (LRF), short light pulses appear during cold testing, which can have unsettling effects or irritate road users.

[0005] LEDs used in vehicles must effectively suppress this flickering during cold inspections. For example, the law requires that no flickering occur if a voltage pulse of less than 2 milliseconds is applied to the lamp input.

[0006] Several solutions exist for this problem, such as connecting a large capacitor to the lamp input. However, these solutions have the problem that, in general, they require too much volume.

[0007] While known solutions can suppress flash, they also require a considerable amount of space. This is particularly problematic for so-called direct-mount lamps, which have a small size similar to halogen lamps.

[0008] One object of this invention is to provide a device for suppressing the flickering of LED elements in vehicle lights during cold inspection, a circuit for vehicle lights, an LED light emitter, and a vehicle, which overcome the aforementioned disadvantages. Utility Model Content

[0009] This objective is achieved by the device according to the present invention, the circuit according to the present invention, the LED light emitter according to the present invention, and the vehicle according to the present invention.

[0010] The device according to this invention is used to suppress the flickering of LED elements in vehicle lights during cold inspections (see the introduction section). Therefore, it is essentially used to ensure that other road users are not confused or startled by the flashing lights.

[0011] The device includes electronic components in an integrated circuit having multiple connectors for electrical connections. The integrated circuit includes the following components:

[0012] - VCC connector for input power supply voltage,

[0013] - GND connector for output power supply voltage

[0014] -A signal connector used to output an on / off signal.

[0015] - A capacitor connector for connecting an external capacitor.

[0016] - The charging circuit applies a positive voltage to the capacitor connector via a charging resistor when the LED element is externally connected.

[0017] - An LED switch is connected in such a way that it outputs an on signal to the signal connector when a predetermined voltage is exceeded on the capacitor connector.

[0018] Because space is very limited for light emitters in vehicles, the electronic components of this device must be housed within integrated circuits. In addition to the LED elements, a driver module is typically already present in the light emitter, which connects to other electronic components (such as suppressor units and bridge rectifiers). The device can be housed within the driver module, representing the driver module itself, or additionally included in the circuitry (as a module with integrated circuits), and communicates with the driver module via signal connectors.

[0019] The device includes (at least) VCC connectors, GND connectors, signal connectors, and capacitor connectors. These connectors can be designed as pins of integrated circuit components, i.e., external connectors to the IC, but they can also simply serve as contact points to other components of the integrated circuit.

[0020] The VCC and GND connectors are used to apply the power supply voltage. The VCC connector should be positive (“plus”) and the GND connector should be negative (“minus”). This power supply voltage is preferably the LED power supply voltage (i.e., the power supply voltage for the LED element), but it can also be a different power supply voltage. A separate voltage source can be used to power the circuit or provide voltage for lighting (typically 12 volts in buses).

[0021] The charging circuit is used to charge a capacitor, which is preferably not part of the device, but is preferably connected externally to the integrated circuit between the capacitor connector and the GND connector. When the LED element is externally switched on, the charging circuit provides a positive voltage to the capacitor connector via a charging resistor. External switching on refers to the vehicle lighting being switched on by a person or vehicle automation system.

[0022] For example, if a separate charging connector is not available, voltage can be supplied to the charging circuit via the VCC connector. The relevant connector can be connected directly to the charging resistor or via a charging switch, and this can be connected to the capacitor connector on the other side. The capacitor can be connected between the capacitor connector and the GND connector.

[0023] The signal connector can be directly connected to the LED element, but preferably, the LED element is powered via a driver circuit, and the signal connector sends an on signal to the driver circuit (e.g., a control input). The driver circuit can exist as a separate integrated circuit, or the device can exist as part of the driver circuit, and everything can be built into an integrated circuit component (IC).

[0024] The LED switch then outputs an ON signal to the signal connector. To do this, the LED switch checks the voltage at the capacitor connector, i.e., the state of charge of the capacitor when it is connected. If the voltage at the capacitor connector exceeds a predetermined voltage, an ON signal is output. For example, the LED switch may include a transistor switch whose base (or gate in the case of a FET) is connected to the capacitor connector. Preferably, when the voltage at the capacitor connector is lower than the predetermined voltage, no ON signal is output to the signal connector, i.e., the lighting is off.

[0025] The small size of the device is very important. Therefore, it is designed as an integrated circuit, i.e., housed in a (small) casing. As mentioned above, the device can be a standalone IC (with external connectors) or it can be integrated into a driver module. In particular, if a transistor switch is used as the switch, the circuit is suitable for manufacturing in a very small size, allowing the device to be manufactured as an integrated component.

[0026] The circuit for vehicle lighting according to this invention includes an LED element, a device according to this invention, and a capacitor connected between a capacitor connector and a GND connector. The circuit is connected in such a way that the LED element illuminates when it receives an on / off signal. Preferably, the LED element is controlled by a driver module, and the on / off signal is sent directly from the device to the driver module.

[0027] The LED light emitter according to this invention includes the circuitry of this invention and includes at least two power connectors connected to the integrated circuit and LED elements of the device, providing energy to the LED elements for illumination. In the case of two different switchable light sources, such as high beams and low beams, the light emitter may also include three or more power connectors. The power connectors can be arranged in such a way that polarity reversal is impossible; this would be advantageous if the light emitter included several bridge rectifiers for adjusting the internal polarity.

[0028] The vehicle according to this utility model includes an LED light emitter according to this utility model.

[0029] The dependent claims and the following description disclose particularly advantageous embodiments and features of the present invention. Features of the embodiments may be appropriately combined. Features described in the context of one claim class may be equally applicable to another claim class.

[0030] The preferred device is characterized in that the integrated circuit for the charging circuit additionally has at least two lighting connectors for connecting to the LED power supply voltage, which supplies power to the LED elements and is turned on by the user to activate the LED elements. Two lighting connectors are generally sufficient if only one group of LEDs or only one LED element should be switched; three lighting connectors are advantageous if two groups of LEDs or two LEDs should be switched. If N groups of LEDs or N LED elements should be switched, then N+1 lighting connectors are preferred.

[0031] The preferred device is characterized by the fact that the integrated circuit includes a voltage divider between the lighting connectors, and via this voltage divider, a switch (particularly a transistor switch) is used to apply a charging voltage to the capacitor connector. The voltage divider preferably generates a switching voltage. Regarding the transistor switch, the switched positive connector (i.e., the collector or source in the case of a FET) is preferably connected to a contact for the positive lighting voltage, the switched negative connector (i.e., the emitter or drain in the case of a FET) is preferably connected to a charging resistor, and the switch input (i.e., the base or gate in the case of a FET) is connected to a voltage divider contact. The voltage divider is preferably formed by the series connection of two resistors between the lighting connectors.

[0032] The switch is preferably connected in such a way that when the LED power supply voltage is turned on, it provides a positive LED power supply voltage to the capacitor connector via the charging resistor, and when the LED power supply voltage is turned off, it does not provide a positive LED power supply voltage to the capacitor connector via the charging resistor.

[0033] In preferred devices, the charging circuit includes reverse polarity protection at the lighting connector, particularly in the form of a bridge rectifier circuit. The VCC and GND connectors are preferably not connected to this bridge rectifier circuit, but rather specifically to an external bridge rectifier circuit, for example, for powering a driver module. Bridge rectifier circuits are known in the art and typically comprise a circuit of four diodes.

[0034] A preferred device is characterized in that the LED switch includes a transistor switch that pulls the signal connector to the GND connector when the voltage on the capacitor connector is lower than a predetermined voltage. In this state, the transistor switch does not output an ON signal. Preferably, the switching input of the LED switch (e.g., its base or gate in the case of a FET) is connected to a voltage divider between the VCC connector and the GND connector. However, in this case, the device is preferably designed such that the LED switch can also receive a switching signal at its switching input.

[0035] The preferred device is characterized in that the LED switch includes an intermediate switch, preferably a transistor switch, particularly in the form of a field-effect transistor, which is connected in such a way that when the voltage on the capacitor connector exceeds a predetermined voltage, it disables the LED switch, wherein the LED switch disabled in this case outputs an on signal, preferably wherein when the LED switch is disabled, its switch input is pulled to the GND connector by bypassing a portion of the voltage divider between the VCC connector and the GND connector.

[0036] In an alternative preferred device, when the voltage on the capacitor connector exceeds a predetermined voltage, the LED switch is connected to switch the LED switch to transmission, in which case the transmission LED switch outputs an on signal.

[0037] The preferred device is characterized in that the turn-on signal is a continuous signal, which exists as long as the LED element should light up (and does not exist when the LED element should not light up).

[0038] The preferred device is characterized by supplying power to the LED element via a driver module having a control input, and the turn-on signal being designed such that the LED element illuminates when the driver module is connected to a predetermined LED power supply voltage and receives the turn-on signal via the control input. Preferably, the turn-on signal is a GND signal, and the control input is pulled to a positive voltage via a pull-up resistor. This pull-up resistor can be externally connected or can be an internal component of the driver module.

[0039] The preferred device is characterized by the fact that, in integrated circuits, electronic components are enclosed in a housing, and particularly in a plastic housing, with connectors extending from the housing. Alternatively, the device is part of a driver module and integrated into its housing.

[0040] Preferably, the housing has a maximum dimension of 5 mm in terms of its height, width, and length. Dimensions SOT-26 (1.1 mm × 3.0 mm × 2.8 mm) or SOT-363 (2.15 mm × 2.10 mm × 1.00 mm) are particularly preferred. Generally, the length and width should preferably not exceed 4 mm, especially not exceed 3 mm, and the height should not exceed 3 mm. This applies to the entire device and its surrounding housing. All electronic components of the device must then be designed in such a way that they have space within their circuitry within this volume.

[0041] The preferred circuit is characterized by the fact that the charging circuit and capacitor are designed such that an on-signal is output at least 2 ms, preferably at least 3 ms, after the LED power supply voltage is turned on. This is preferably achieved by ensuring that the total resistance G of the charging circuit for the charging current and the capacitance K of the capacitor are sized such that GK > 2 ms. However, this time should be less than 50 ms, particularly less than 10 ms, so that no noticeable delay is observed when the LED is turned on. It should be noted that the “cold suppression pulse” is typically no more than 2 ms. Although the pulses usually appear as a sequence of three or more pulses with a frequency of several Hz (2-5 Hz), the time interval between the pulses is approximately 100 times larger than the pulse width. Therefore, the capacitor has sufficient time to discharge before the next pulse. Essentially, the capacitance of the capacitor should be chosen so that it can fully discharge within the time between two pulses. Then the subsequent pulse will not cause the LED element to flicker.

[0042] A preferred circuit includes a driver module for supplying power to the LED element. This driver module is known in the prior art and has been described above. The driver module is designed such that it supplies power to the LED element when a predetermined LED power supply voltage and an on signal are present. For this purpose, it is preferred that the driver module has a control input (particularly with a pull-up resistor), and that the device's signal connector is connected to the control input, such that the driver module receives the on signal via the signal connector to its control input.

[0043] Other objects and features of the present invention will become clear from the following detailed description taken in conjunction with the accompanying drawings. However, it should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Attached Figure Description

[0044] Figure 1 The pulse signal used to test the halogen lamp and the LED light source blinking in this case are shown.

[0045] Figure 2 A circuit according to the present invention is shown, having a device according to the present invention.

[0046] Figure 3 The detailed circuit of the device according to this utility model is shown.

[0047] Figure 4 A more detailed circuit diagram of the device according to the present invention is shown. Detailed Implementation

[0048] Figure 1 A conventional halogen lamp is shown on the left. It has three power connectors (bottom), one of which is a common ground, and the other two each power one of the filaments shown. One of these filaments (the one above) is broken, and the other is intact. As shown in the diagram below, if a short current pulse is now applied to the power connector during a cold check, current briefly flows through the intact filament, indicating that it is not broken. However, no current flows through the broken filament, resulting in an error message. Because the 2 ms pulse is very short, the intact filament is not excited to light up.

[0049] The LED on the right is different. It contains a light-emitting diode instead of a filament. If pulses are applied there, the LED will briefly flicker, as indicated by the dotted line. This is undesirable, and this invention compensates for it.

[0050] Figure 2 A circuit according to the present invention is shown in the form of an LED light emitter 3, the circuit having a device 1 according to the present invention for suppressing the flickering of the LED element 2 of the vehicle headlight during cold inspection. Device 1 includes a VCC connector A2, a GND connector A4, a signal connector A3, a capacitor connector A5, a charging circuit SK, and an LED switch SL. The capacitor 5 is arranged between the GND connector A4 and the capacitor connector A5. The signal connector A3 is connected to the LED element 2, and the LED element 2 illuminates when it receives an on signal via the signal connector A3.

[0051] Figure 3 It shows Figure 2A detailed variation of the circuit shown is presented. Here, LED element 2 includes a driver module 4 that provides power to it. The driver module 4 has a control input terminal K connected to signal connector A3. The turn-on signal is designed such that when the driver module is connected to a predetermined LED power supply voltage and receives the turn-on signal via the control input terminal K, LED element 2 lights up.

[0052] Here, the charging circuit SK also includes two lighting connectors A1 and A6, for connecting the LED power supply voltage and the voltage divider R1 and R2 between the lighting connectors A1 and A6. Transistor switch Q1 is switched by this voltage divider R1 and R2 to apply a charging voltage to capacitor connector A5. When the LED power supply voltage is on, the charging current flows through transistor switch Q1 and charging resistor R4 to capacitor connector A5, where it charges capacitor 5.

[0053] The LED switch SL consists of a transistor switch Q3 and an intermediate switch Q2. Transistor switch Q3 is connected to the voltage divider R5, R6, and R7, and it is turned on if there is no switching signal from the intermediate switch Q2. If transistor switch Q3 is on, signal connector A3 is connected to GND, and there is no signal output.

[0054] Intermediate switch Q2 (field-effect transistor) is connected such that if the voltage across capacitor connector A5 exceeds a predetermined voltage (diode D only guarantees the voltage at the FET gate), it disables LED switch SL. In this case, intermediate switch Q2 becomes on, pulling the base of transistor switch Q3 towards GND. The disabled transistor switch Q3 causes LED switch SL to output an on signal.

[0055] Figure 4 A more detailed circuit diagram of the device according to this utility model is shown. It is very similar to... Figure 3 The circuit shown here connects the lighting connectors A1 and A6 to the device 1 via the bridge rectifier circuit G to protect the circuit.

[0056] Finally, it should be reiterated that the present invention described in detail above is merely a matter of embodiments, and those skilled in the art can modify these embodiments in various ways without departing from the scope of the present invention. Furthermore, the use of the indefinite article "a" or "an" does not preclude the possibility that the features in question may appear more than once. Similarly, terms such as "unit" do not preclude the possibility that the components in question may include several interacting sub-components, which may also be spatially distributed. The term "a number" should be interpreted as "at least one".

[0057] List of reference numerals in the attached figures

[0058] 1 Equipment

[0059] 2 LED components

[0060] 3 LED light sources

[0061] 4 Driver Modules

[0062] 5 capacitors

[0063] A1 Lighting Connector

[0064] A2 VCC connector

[0065] A3 signal connector

[0066] A4 GND connector

[0067] A5 Capacitor Connector

[0068] A6 Lighting Connector

[0069] D diode

[0070] G-bridge rectifier

[0071] K control input terminal

[0072] LED

[0073] P pulse signal

[0074] Q1 Transistor Switch

[0075] Q2 Intermediate switch

[0076] Q3 Transistor Switch

[0077] Resistors R1, R2, R3

[0078] R4 Charging Resistor

[0079] Resistors R5, R6, and R7

[0080] SK charging circuit

[0081] SL LED switch.

Claims

1. A device for suppressing flickering of LED elements (2) in vehicle lighting during cold inspection, characterized in that: The device (1) includes electronic components in an integrated circuit having a plurality of connectors for electrical connection, the integrated circuit comprising: - VCC connector (A2) for input power supply voltage. - GND connector (A4) for output power supply voltage. - Signal connector (A3) for outputting a power-on signal. - Capacitor connector (A5) for connecting an external capacitor (5). - Charging circuit (SK), when the LED element (2) is turned on from the outside, the charging circuit applies a positive voltage to the capacitor connector (A5) via the charging resistor (R4), and - An LED switch (SL) is connected in such a way that when a predetermined voltage is output on the capacitor connector (A5), it outputs an on signal to the signal connector (A3).

2. The device (1) according to claim 1, wherein the integrated circuit for the charging circuit (SK) additionally has at least two lighting connectors (A1, A6) for connecting an LED power supply voltage for supplying power to the LED element (2) and for being turned on by the user to turn on the LED element (2).

3. The device (1) according to claim 1 or 2, wherein the integrated circuit includes a voltage divider (R1, R2) between the lighting connectors (A1, A6), and a switch (Q1), in particular a transistor switch, is connected via the voltage divider (R1, R2) to apply a charging voltage to the capacitor connector (A5), wherein the switch (Q1) is connected in such a way that when the LED power supply voltage is on, it provides a positive LED power supply voltage to the capacitor connector (A5) via the charging resistor (R4), and when the LED power supply voltage is off, it does not provide a positive LED power supply voltage to the capacitor connector (A5) via the charging resistor (R4).

4. The device (1) according to claim 1 or 2, wherein the charging circuit (SK) includes reverse polarity protection at the lighting connector, particularly in the form of a bridge rectifier circuit (G), wherein the VCC connector (A2) and the GND connector (A4) are not connected to the bridge rectifier circuit (G).

5. The device (1) according to claim 1 or 2, wherein the LED switch (SL) includes a transistor switch (Q3) that pulls the signal connector (A3) to the GND connector (A4) and therefore does not output an on signal when the voltage on the capacitor connector (A5) is lower than a predetermined voltage, wherein the switch input of the LED switch (SL) is connected to a voltage divider between the VCC connector (A2) and the GND connector (A4).

6. The device (1) according to claim 1 or 2, wherein the LED switch (SL) includes an intermediate switch (Q2) comprising a transistor switch, particularly in the form of a field-effect transistor, which is configured such that when the voltage on the capacitor connector (A5) exceeds a predetermined voltage, it disables the LED switch (SL), wherein in this case, the disabled LED switch (SL) outputs an on signal, wherein when the LED switch (SL) is disabled, its switch input is pulled to the GND connector (A4) by bypassing a portion of the voltage divider between the VCC connector (A2) and the GND connector (A4).

7. The device (1) according to claim 1 or 2, wherein the turn-on signal is a continuous signal that exists as long as the LED element (2) is supposed to emit light.

8. The device (1) according to claim 1 or 2, wherein power is supplied to the LED element (2) by means of a driver module (4), wherein the driver module (4) has a control input (K), and wherein an on signal is designed such that when the driver module (4) is connected to a predetermined LED power supply voltage and receives an on signal via the control input (K), wherein the on signal is a GND signal and the control input (K) is pulled to a positive voltage via a pull-up resistor.

9. The device (1) according to claim 1 or 2, wherein in the integrated circuit, the electronic components are surrounded by a housing, and in particular encapsulated in a plastic housing, and the connector extends from the housing. The outer shell has a maximum dimension of 5 mm in terms of height, width and length.

10. A circuit for vehicle lighting, characterized in that: The circuit includes an LED element (2), a device (1) according to any one of the preceding claims, and a capacitor (5) connected between a capacitor connector (A5) and a GND connector (A4), wherein the circuit is configured such that the LED element (2) lights up when it receives an on signal.

11. The circuit according to claim 10, wherein the charging circuit (SK) and the capacitor (5) are designed such that an on signal is output at least 2 ms after the LED power supply voltage is turned on. The total resistance G of the charging circuit (SK) used for the charging current and the capacitance K of the capacitor (5) are set such that GK > 2 ms.

12. The circuit according to claim 11, wherein an on signal is output at least 3 ms after the LED power supply voltage is turned on.

13. The circuit according to any one of claims 10 to 12, characterized in that... The circuit includes a driver module (4) for supplying energy to the LED element (2) when a predetermined LED power supply voltage and an on signal are present, wherein the driver module (4) has a control input (K) and the signal connector (A3) of the device (1) is connected to the control input (K) such that the driver module (4) receives the on signal via the signal connector (A3) to its control input (K).

14. An LED light emitter (3), characterized in that: The LED light emitter (3) includes a circuit according to any one of claims 10 to 13, and includes at least two power connectors connected to the integrated circuit and LED element (2) of the device (1), and providing energy for lighting to the LED element (2).

15. A vehicle characterized by: The vehicle includes an LED light emitter (3) according to claim 14.

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