Vehicle lighting systems

Abstract

A vehicle lighting system is provided. The object of the present invention is to detect light source failures earlier. The vehicle lighting system includes: a plurality of light sources; a power supply for supplying driving voltage to the plurality of light sources; a control device that individually controls the lighting state and the extinguishing state of each of the plurality of light sources; and a fault detection circuit that is connected to the control device and detects faults of the plurality of light sources. After the control device controls all of the plurality of light sources from the extinguishing state to the lighting state in response to the start of the vehicle, the control device controls the plurality of light sources to the extinguishing state in sequence. At this time, the control device obtains the fault detection result performed by the fault detection circuit at least during the period when each of the plurality of light sources transitions from the extinguishing state to the lighting state, and generates a warning signal when the fault exists.

Description

Technical Field

[0001] The present disclosure relates to a lighting system for a vehicle. Background Art

[0002] Japanese Patent Gazette No. 6130105 (Patent Document 1) discloses a vehicle lighting system that, when the vehicle's ignition switch is on, causes multiple light sources of a first light source group and multiple light sources of a second light source group to be lit in sequence. The vehicle lighting system includes a detection unit that detects abnormalities (faults) of the light sources when they are lit in sequence.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6130105 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] One of the purposes of a specific embodiment of the present disclosure is to detect light source failure earlier.

[0008] Means for solving problems

[0009] A vehicle lighting system according to one embodiment of the present invention is a vehicle lighting system comprising: (a) a plurality of light sources; (b) a power supply for supplying driving voltage to the plurality of light sources; (c) a control device for individually controlling the lighting state and the extinguishing state of each of the plurality of light sources; and (d) a fault detection circuit connected to the control device for detecting faults of the plurality of light sources, (e) after the control device controls all of the plurality of light sources from the extinguishing state to the lighting state in response to the start of the vehicle, the control device sequentially and individually controls the plurality of light sources to the extinguishing state, and at this time, the control device obtains the detection result of the fault performed by the fault detection circuit at least during the period when each of the plurality of light sources transitions from the extinguishing state to the lighting state, and generates a warning signal when the fault exists.

[0010] According to the above configuration, a failure of the light source can be detected earlier. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 1 is a diagram showing a configuration of a vehicle lighting system according to an embodiment.

[0012] Figure 2 : is a circuit diagram showing an example of the circuit configuration of a lamp unit.

[0013] Figure 3This is a conceptual diagram for explaining the operation of a vehicle headlamp system.

[0014] Figure 4 It is represented by a timing diagram Figure 3 The diagram shows the operation of the vehicle lighting system.

[0015] Figure 5 This is a conceptual diagram for explaining the operation of a vehicle headlamp system according to another embodiment.

[0016] Figure 6 This is a conceptual diagram for explaining the operation of a vehicle headlamp system according to another embodiment.

[0017] Label Description

[0018] 10: Power supply circuit, 11a, 11b, 11c, 11d, 11e: Light emitting element, 12a, 12b, 12c, 12d, 12e: Switching element, 13a, 13b, 13c, 13d, 13e: Resistor, 14: Control circuit, 15: Fault detection circuit DETAILED DESCRIPTION

[0019] Figure 1 This is a diagram showing the structure of a vehicle lighting system according to one embodiment. The vehicle lighting system according to this embodiment is configured to include a lamp unit 1L provided on the left side of the front portion of the vehicle and a lamp unit 1R provided on the right side of the front portion of the vehicle. These lamp units 1L and 1R are respectively provided with five lighting and extinguishing sections 1a, 1b, 1c, 1d, and 1e. These lighting and extinguishing sections 1a and 1R can be switched on and off independently. The lamp units 1L and 1R according to this embodiment are used, for example, to form irradiation light including a dimming area (or a light-shielding area) that is set according to the conditions of an oncoming vehicle, a preceding vehicle, etc., existing in front of the vehicle. An H / L signal indicating the operating state of a switch for instructing the lighting of the vehicle's lamps and an IG signal indicating the operating state of an ignition switch are input to the lamp units 1L and 1R.

[0020] Figure 2This is a circuit diagram showing an example of the circuit structure of a lamp unit. Since lamp units 1L and 1R have the same structure, only the circuit structure of lamp unit 1L is shown here. The illustrated lamp unit 1L includes a power supply circuit (power supply) 10, five light-emitting elements (LEDs) 11a, 11b, 11c, 11d, and 11e, five switching elements 12a, 12b, 12c, 12d, and 12e, five resistors 13a, 13b, 13c, 13d, and 13e, a control circuit 14, and a fault detection circuit 15. In this embodiment, each light-emitting element 11a and the like corresponds to a "light source," while the five switching elements 12a, 12b, 12c, 12d, and 12e and the control circuit 14 correspond to a "control device."

[0021] The power supply circuit 10 is connected to the anode side of each light emitting element 11 a and supplies a driving voltage for causing each light emitting element 11 a to emit light. The power supply circuit 10 is also connected to the control circuit 14 and adjusts the driving voltage based on a control signal provided by the control circuit 14 .

[0022] Each light-emitting element 11a, 11b, 11c, 11d, and 11e is connected in parallel, with its anode connected to the power supply circuit 10 and its cathode connected to each switching element 12a, etc. In this embodiment, light-emitting element 11a corresponds to the aforementioned on / off section 1a, light-emitting element 11b corresponds to the aforementioned on / off section 1b, light-emitting element 11c corresponds to the aforementioned on / off section 1c, light-emitting element 11d corresponds to the aforementioned on / off section 1d, and light-emitting element 11e corresponds to the aforementioned on / off section 1e.

[0023] In addition, although the case where each light emitting element corresponds to one lighting and turning-off section is shown here as an example, a plurality of light emitting elements may correspond to each lighting and turning-off section.

[0024] One input / output terminal of switching element 12a is connected to the cathode side of light-emitting element 11a, the other input / output terminal is connected to one end of resistor 13a, and the control terminal is connected to control circuit 14. The connection relationship between the other switching elements 12b-12e and the light-emitting elements 11b-11e, resistors 13b-13e, and control circuit 14 is the same as that of switching element 12a. For example, field-effect transistors as shown in the figure can be used as each switching element 12a, but other switching elements such as bipolar transistors can also be used. Based on the control signal provided to each control terminal by the control circuit 14, each switching element 12a increases or decreases the current flowing in the current path according to whether the pair of input / output terminals (current path) is open or closed, or the control signal provided to the control terminal when the current path is open.

[0025] One end of each of the resistor elements 13a to 13e is connected to each of the switching elements 12a to 12e, and the other end is connected to the reference potential terminal (GND). These resistor elements 13a and the like serve as current limiting resistors for each of the light emitting elements 11a and the like.

[0026] The control circuit 14 is connected to each switching element 12a, etc., and provides a control signal to the control terminal of each switching element 12a, etc. Furthermore, the control circuit 14 is connected to the current path between each resistor element 13a, etc. and the reference potential terminal, detects the current flowing through each resistor element 13a, etc., and controls the power supply circuit 10 so that the magnitude of the current flowing through each resistor element 13a, etc. is a predetermined magnitude. Furthermore, if a fault in each light-emitting element 11a, etc. is detected by the fault detection circuit 15, the control circuit 14 outputs a predetermined warning signal to a higher-level device (not shown) (e.g., a control unit included in the vehicle) and performs other controls, such as stopping the supply of drive voltage to the power supply circuit 10. The control circuit 14 can be implemented as hardware composed of a combination of an IC and circuit elements, or can be implemented using a microcomputer and software executed by the microcomputer.

[0027] The fault detection circuit 15 is connected between the power supply circuit 10 and each light-emitting element 11a, etc., and detects any faults in each light-emitting element 11a, etc. The faults referred to here are short circuit faults (short faults) or open circuit faults (open faults). Specifically, if a short circuit fault or open circuit fault occurs in any of the light-emitting elements 11a, etc., the amount of current flowing out of the power supply circuit 10 increases or decreases compared to the expected amount. Therefore, the fault detection circuit 15 detects the current amount and outputs a fault detection signal to the control circuit 14 if the current amount increases or decreases from a predetermined reference value.

[0028] Figure 3 This is a conceptual diagram used to illustrate the operation of a vehicle headlamp system. In the figure, segment numbers 1, 2, 3, 4, and 5 correspond to the on / off segments 1a, 1b, 1c, 1d, and 1e of each lamp unit 1L and 1R, respectively. As shown in the figure, the on / off segments 1a and 1e of each lamp unit 1L and 1R are arranged symmetrically, with segment numbers increasing toward the center of the vehicle. As shown in the figure, the on / off segment 1d with segment number 4 in each lamp unit 1L and 1R corresponds to the light irradiated at center c in front of the vehicle. In the figure, blocks marked with patterns indicate an on / off segment of "on," while blocks without patterns indicate an on / off segment of "off." Periods T0 to T6 represent the on / off status in a time series, progressing sequentially from T0 to T6. The intervals between periods T0 to T6 are not necessarily required.

[0029] For example, if the ignition switch of the vehicle is turned on (started) at period T0, all the on / off segments 1a to 1e of segment numbers 1 to 5 are controlled to be in the on state at the next period T1. In the following period T2, the on / off segment 1a of segment number 1 is controlled to be in the off state, and the other on / off segments are maintained in the on state. In the following period T3, in addition to segment number 1, the on / off segment 1b of segment number 2 is controlled to be in the off state, and the other on / off segments are maintained in the on state. In the following period T4, in addition to segments numbers 1 and 2, the on / off segment 1c of segment number 3 is controlled to be in the off state, and the other on / off segments are maintained in the on state. At the next time, T5, in addition to segments 1, 2, and 3, the on / off segment 1d of segment number 4 is controlled to the off state, while the on / off segment 1e of segment number 5 remains on. At the following time, T6, the on / off segments corresponding to all segment numbers are controlled to the off state. Specifically, as a whole, all on / off segments are first controlled to the on state. Then, starting with the on / off segments corresponding to the outer sides of the vehicle (segments with smaller segment numbers), the on / off segments are individually controlled to the off state, and finally, all on / off segments are controlled to the off state.

[0030] Figure 4 It is represented by a timing diagram Figure 3 The diagram shows the operation of the vehicle lighting system. In the diagram, the symbols SEG1 to SEG5 correspond to the segment numbers 1 to 5 described above, respectively. Furthermore, "IG" indicates the on / off status of the ignition signal, "H / L" indicates the status of the H / L signal (lit / off), "Fault Detect" indicates the status of the fault detection circuit 15 (not implemented / started / confirmed), and "WN" indicates the status of the warning signal (lit / off).

[0031] As shown in the figure, the ignition signal is turned on (time T0: refer to Figure 3 ), and then, if the H / L signal becomes a state indicating lighting, all the lighting and extinguishing segments 1a to 1e corresponding to segment numbers 1 to 5 change from extinguishing to lighting. Specifically, the control circuit 14 controls each switching element 12a to 12e to be in the open state, and current flows to each light-emitting element 11a to 11e, and each light-emitting element 11a to 11e is lit. In the present embodiment, the period during which each light-emitting element 11a, etc. transitions from the extinguishing state to the lighting state is set to substantially the same length (for example, 0.7 seconds each). In addition, in the present embodiment, each light-emitting element 11a, etc. starts the transition from the extinguishing state to the lighting state at substantially the same timing and reaches the lighting state at substantially the same timing.

[0032] At this point, the control circuit 14 begins fault detection based on the fault detection signal output from the fault detection circuit 15 in response to the control of the switching element 12a, etc. from the closed state to the open state. Specifically, during the period when each light-emitting element 11a, etc. transitions from the extinguished state to the illuminated state, and while the light-emitting element 11a, etc. remains illuminated, the control circuit 14 receives the fault detection signal output from the fault detection circuit 15 and performs fault detection based on the detection results. Furthermore, if a fault occurs in any of the light-emitting elements 11a to 11e, the fault detection signal output from the fault detection circuit 15 causes the control circuit 14 to switch the warning signal to "illuminate" based on this. In other words, the control circuit 14 generates a warning signal corresponding to the presence of a fault. Upon receiving the warning signal from the control circuit 14, the warning light in the host device illuminates.

[0033] By illuminating all light-emitting elements 11a through 11e simultaneously and performing fault detection accordingly, the driver, etc., can be promptly notified of a fault if one occurs. The time required from turning on the ignition switch to generating a warning signal and illuminating the warning light is constant, regardless of the location of the faulty light-emitting element, offering the advantage of completing the task in a short time. Furthermore, by initially illuminating all light-emitting elements 11a through 11e, fault detection can be performed initially under the maximum load on the power supply circuit 10, etc., allowing for rapid fault detection.

[0034] After each light emitting element 11a to 11e is turned on, the control circuit 14 sequentially controls the switch elements 12a to 12e to be closed according to the time difference, so that each light emitting element 11a to 11e is turned off according to the time difference. Figure 3 As shown, the lighting and extinguishing sections 1a to 1e are extinguished in sequence in a predetermined order.

[0035] According to the above-described embodiment, a failure of a light emitting element (light source) can be detected earlier.

[0036] In addition, the present disclosure is not limited to the contents of the above-mentioned embodiment, and can be implemented in various modifications within the scope of the main purpose of the present disclosure. For example, the circuit structure of the lamp unit is not limited to Figure 2 The illustrated structure can be implemented with various modifications. Furthermore, the number of on / off segments included in each lamp unit 1L, 1R is not limited to that in the above-described embodiment. Furthermore, the arrangement of the on / off segments in each lamp unit 1L, 1R is not limited to the arrangement along one direction as illustrated in the above-described embodiment.

[0037] The lamp units 1L and 1R are not limited to high beams and may be used as other types of vehicle lamps, such as turn signals. A light emitting element (LED) is shown as an example of a light source, but the light source is not limited thereto and may be a laser element, for example.

[0038] In addition, the ignition signal is used to detect the start of the vehicle, but other signals may be used. For example, in the case of a vehicle without an internal combustion engine, such as a so-called electric vehicle, an internal signal indicating the start of the vehicle may be used instead of the ignition signal.

[0039] In addition, after the ignition signal is turned on, the following actions can be repeated multiple times: after all the lighting and extinguishing sections are all lit, they are extinguished in sequence according to the time difference. Figure 5 As shown, the same operation as that of period T0 to T5 can be performed in period T6 to T11 (see Figure 3 ) The same action is performed each time, and fault detection is performed each time. Furthermore, the same action can be performed for the third time and thereafter. By performing the action multiple times, fault detection can be performed more reliably.

[0040] In addition, after the ignition signal is turned on, when all the lighting and extinguishing sections are lit and then extinguished in sequence according to the time difference, instead of extinguishing each lighting and extinguishing section immediately, a period in which the luminance (brightness) is reduced to a mid-tone state may be provided in the middle to extinguish the sections in a graded manner. Figure 6 As shown, it can also be combined with the action of period T0 to T5 (refer to Figure 3 ) Similarly, after the lighting and extinguishing segment is illuminated, the lighting state with the brightness reduced to half (50%) is maintained for a certain period. Specifically, for example, in the lighting and extinguishing segment of segment number 1, after the lighting state is established during period T1, a mid-tone period with the brightness reduced to half is provided during periods T2 to T7, and then the lighting state is established during period T8. The lighting and extinguishing segments of other segment numbers are similarly controlled so that the mid-tone period with the brightness reduced to half and the period of extinguishing occur at a time difference.

[0041] Thus, by turning off the light in multiple levels with the lighting period of half the light intensity, it is possible to detect a fault in the circuit for controlling the light intensity in multiple levels. Figure 2In the illustrated circuit, the current flowing between the input and output terminals (current path) of each of the switching elements 12a-12e is controlled, thereby increasing or decreasing the current flowing through each of the light-emitting elements 11a-11e, thereby controlling the intensity of the emitted light in multiple steps. In this case, if there is a failure in the switching element 12a itself, or a failure in the control circuit 14, the current flow may not reach the point flow corresponding to the specified intensity, and this can be detected by the fault detection circuit 15.

Claims

1. A vehicle lighting system, comprising: Multiple light sources; a power supply for supplying a driving voltage to the plurality of light sources; a control device for individually controlling a lighting state and an extinguishing state of each of the plurality of light sources; as well as a fault detection circuit connected to the control device and detecting a fault of the plurality of light sources, After the control device controls all of the multiple light sources from the off state to the lit state in response to the start of the vehicle, the control device controls the multiple light sources individually to the off state in sequence, and at this time, the control device obtains the detection result of the fault performed by the fault detection circuit during the period when at least each of the multiple light sources transitions from the off state to the lit state, and generates a warning signal when the fault exists.

2. The vehicle lighting system according to claim 1, wherein: The control device detects start of the vehicle based on a signal obtained from the vehicle.

3. The vehicle lighting system according to claim 1 or 2, wherein: The control device repeatedly performs the following actions multiple times in response to the start of the vehicle: after controlling all of the multiple light sources from the off state to the lit state, the multiple light sources are individually controlled to the off state in turn; when performing each of the above multiple actions, at least during the period when all of the multiple light sources are transformed from the off state to the lit state, the fault detection result performed by the fault detection circuit is obtained, and a warning signal is generated when the fault exists.

4. The vehicle lighting system according to any one of claims 1 to 3, wherein: The control device controls in the following manner: when all the multiple light sources are controlled from the off state to the lit state in response to the start of the vehicle and then the multiple light sources are individually controlled to the off state in sequence, for each of the multiple light sources, during the transition from the lit state to the off state, there is a period in which an intermediate tone state of a specific brightness between the lit state and the off state is maintained.

5. The vehicle lighting system according to any one of claims 1 to 4, wherein: A period during which each of the plurality of light sources transitions from the off state to the on state is set to have substantially the same length.

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