Control device for vehicle lighting, vehicle lighting, and program

Abstract

To execute temperature derating control with no hindrance, by suppressing an increase in costs of a vehicular lamp fitting, and after satisfying a request received by a plurality of functions (lighting modes) set in the vehicular lamp fitting.SOLUTION: A control device 29 of a vehicular lamp fitting 1 executes temperature derating control of the vehicular lamp fitting 1 comprising a lighting part 10 for lighting in a plurality of lighting modes, and one temperature detection part 30 for detecting a temperature inside or around a lamp chamber. The control device comprises: a non-volatile memory part 23 for storing a plurality of pieces of temperature derating information regulated by a temperature inside or around a lamp chamber, and electric power inputted to the lighting part 10, for each lighting mode of the lighting part 10; and a power control part 22 for controlling electric power inputted to the lighting part 10, in accordance with a lighting mode of the lighting part 10, a temperature inside or around a lamp chamber detected by the temperature detection part 30, and the temperature derating information stored in the non-volatile memory part 23.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for vehicle lighting equipment, vehicle lighting equipment, and a program. [Background technology]

[0002] As a control device for vehicle lighting equipment, there are known devices that perform temperature derating control to protect light-emitting elements from overheating (see, for example, Patent Documents 1 and 2). In the control device described in Patent Document 1, temperature derating control is performed for the first to fourth light sources based on the outputs of the first to third thermistors and the input voltage of the drive circuit. In the control device described in Patent Document 2, temperature derating control is performed for a single light-emitting element based on the outputs of the first and second temperature sensors. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-49514 [Patent Document 2] Japanese Patent Publication No. 2018-122742 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In recent years, vehicle lighting systems have been equipped with multiple light-emitting units, each with its own function, such as high beam, low beam, daytime running lights (DRL / POS), and turn signals or hazard lights. Each light-emitting unit has different requirements depending on the function it performs. For example, a light-emitting unit responsible for turn signals is required to illuminate while maintaining visibility even in relatively high-temperature environments. Similarly, a light-emitting unit that performs daytime running lights is required to illuminate at ambient temperatures during daytime driving. In other words, temperature derating control for each light-emitting unit must be performed individually according to the function set for each unit.

[0005] In addition, as described in Patent Documents 1 and 2, when temperature derating control is performed for one or more light-emitting units based on the output of multiple temperature detection elements, the number of temperature detection elements, connection wiring, input circuits for the control device, and input terminals for the control device increases, which raises the cost of the vehicle lighting equipment.

[0006] In view of the above circumstances, the present invention aims to provide a control device for vehicle lighting equipment, a vehicle lighting equipment, and a program that can suppress the increase in the cost of vehicle lighting equipment, satisfy the requirements of multiple functions (lighting modes) set in the vehicle lighting equipment, and perform temperature derating control without hindrance. [Means for solving the problem]

[0007] The present invention includes a lighting unit that lights up in multiple lighting modes, and a lighting chamber. around surrounding atmosphere A control device for a vehicle light fixture that performs temperature derating control of a vehicle light fixture, comprising a temperature detection unit that detects temperature, wherein for each lighting mode of the lighting unit, the light room around surrounding atmosphere A storage unit that stores a plurality of temperature derating information defined by temperature and power or current input to the lighting unit, the lighting mode of the lighting unit, and the lighting chamber detected by the temperature detection unit. aroundSurrounding atmosphere A control unit that controls the power or current input to the lighting unit according to the temperature and the temperature dilating information stored in the storage unit.

[0008] The present invention relates to a lighting unit that lights in a plurality of lighting modes, a lamp chamber around Surrounding atmosphere A vehicle lamp including one temperature detection unit that detects the temperature of the surrounding and a control device that executes temperature dilating control of the lighting unit. The control device, for each lighting mode of the lighting unit, the lamp chamber around Surrounding atmosphere A storage unit that stores a plurality of temperature dilating information defined by the temperature and the power or current input to the lighting unit, the lighting mode of the lighting unit, and the lamp chamber detected by the temperature detection unit around Surrounding atmosphere A control unit that controls the power or current input to the lighting unit according to the temperature and the temperature dilating information stored in the storage unit.

[0009] The present invention relates to a lighting unit that lights in a plurality of lighting modes, a lamp chamber around Surrounding atmosphere A program for causing a control device to execute temperature dilating control of a vehicle lamp including one temperature detection unit that detects the temperature of the surrounding and a lighting unit that lights in a plurality of lighting modes. For each lighting mode of the lighting unit, the lamp chamber around Surrounding atmosphere A procedure for storing a plurality of temperature dilating information defined by the temperature and the power or current input to the lighting unit in a storage unit, the lighting mode of the lighting unit, and the lamp chamber detected by the temperature detection unit around Surrounding atmosphere A procedure for causing the control device to control the power or current input to the lighting unit according to the temperature and the temperature dilating information stored in the storage unit.

Advantages of the Invention

[0010] According to the present invention, it is possible to suppress an increase in the cost of a vehicle lamp, satisfy the requirements received by a plurality of functions (lighting modes) set for the vehicle lamp, and perform temperature derating control without any trouble.

Brief Description of the Drawings

[0011] [Figure 1] FIG. 1 is a side sectional view showing an outline of a vehicle lamp according to an embodiment of the present invention. [Figure 2] FIG. 2 is a circuit diagram showing an outline of the vehicle lamp shown in FIG. 1. [Figure 3] FIGS. 3(A) to (D) are graphs showing control characteristics for each function of the lighting unit shown in FIG. 2. [Figure 4] FIG. 4 is a table showing control characteristics for each function of the lighting unit shown in FIG. 2. [Figure 5] FIG. 5 is a circuit diagram showing an outline of a vehicle lamp according to a comparative example. [Figure 6] FIG. 6 is a graph showing control characteristics of a night-time light-emitting unit and a daytime light-emitting unit shown in FIG. 5. [Figure 7] FIG. 7 is a circuit diagram showing an outline of a vehicle lamp according to a comparative example. [Figure 8] FIG. 8 is a graph showing control characteristics of the night-time light-emitting unit shown in FIG. 7. [Figure 9] FIG. 9 is a circuit diagram showing an outline of a vehicle lamp according to a comparative example. [Figure 10] FIG. 10 is a side sectional view showing an outline of a vehicle lamp according to another embodiment of the present invention. [Figure 11] FIG. 11 is a side sectional view showing an outline of a vehicle lamp according to another embodiment of the present invention.

Mode for Carrying Out the Invention

[0012] The present invention will be described below in accordance with preferred embodiments. However, the present invention is not limited to the embodiments shown below, and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some parts of the configuration are omitted in terms of illustration and description. For details of the omitted technologies, publicly known or well-known technologies can be applied as appropriate, to the extent that they do not contradict the content described below.

[0013] Figure 1 is a schematic side cross-sectional view of a vehicle light fixture 1 according to one embodiment of the present invention. The vehicle light fixture 1 shown in this figure is a headlight and comprises a lighting unit 10, a lighting circuit 20, a temperature detection unit 30, a body 40, and an outer lens 50. The lighting unit 10 comprises a plurality of light-emitting units 10A, 10B, 10C, and 10D (see Figure 2). The body 40 is a frame with an opening on the front side of the vehicle. The outer lens 50 is attached to the front end of the body 40 so as to close the opening of the body 40. The body 40 and the outer lens 50 constitute a light chamber 2.

[0014] The lighting unit 10, the lighting circuit 20, and the temperature detection unit 30 are arranged within the lamp chamber 2. The lighting unit 10 is located in the upper area of ​​the lamp chamber 2. The multiple light-emitting units 10A, 10B, 10C, and 10D of the lighting unit 10 are arranged offset in the vehicle width direction. The temperature detection unit 30 is located in the lower area of ​​the lamp chamber 2. Furthermore, the lighting circuit 20 is located in the area between the lighting unit 10 and the temperature detection unit 30. Note that the multiple light-emitting units 10A, 10B, 10C, and 10D may be arranged as appropriate according to the design of the vehicle lamp 1, for example, they may be arranged offset in the vertical direction.

[0015] Here, the lighting unit 10 and the temperature detection unit 30 are arranged vertically separated via the lighting circuit 20. The ambient temperature in the upper region of the lamp chamber 2 where the lighting unit 10 is located is affected by the heat generated by the light-emitting units 10A, 10B, 10C, and 10D. In contrast, the ambient temperature in the lower region of the lamp chamber 2 where the temperature detection unit 30 is located is less affected by the heat generated by the light-emitting units 10A, 10B, 10C, and 10D, and is relatively stable. If the heat generated by the light-emitting units 10A, 10B, 10C, and 10D affects the ambient temperature of the temperature detection area detected by the temperature detection unit 30, the temperature rise in the temperature detection area due to that heat is preferably 5°C or less, more preferably 3°C or less, and even more preferably 2°C or less.

[0016] The lighting unit 10 has multiple light-emitting units 10A, 10B, 10C, and 10D, each of which is set to a different function (lighting mode). The function of light-emitting unit 10A is high beam, the function of light-emitting unit 10B is daytime running light (DRL / POS), the function of light-emitting unit 10C is low beam, and the function of light-emitting unit 10D is turn signal or hazard light. It is also possible to set multiple functions to a single light-emitting unit. For example, daytime running light and low beam may be set to a single light-emitting unit. In this case, the light-emitting unit will dim from the low beam lighting mode and transition to the daytime running light lighting mode.

[0017] Figure 2 is a schematic circuit diagram of the vehicle lighting device 1 shown in Figure 1. As shown in this figure, the vehicle lighting device 1 has a lighting unit 10 which comprises a plurality of light-emitting units 10A, 10B, 10C, and 10D. Each of the plurality of light-emitting units 10A, 10B, 10C, and 10D comprises a plurality of light-emitting elements 11 and an optical system (not shown).

[0018] The light-emitting element 11 is an LED (Light Emitting Diode) or a laser diode, and its brightness is controlled by the lighting circuit 20. For example, if the light-emitting element 11 is an LED, the brightness is controlled by controlling the lighting time using the PWM (Pulse Width Modulation) method. Multiple light-emitting elements 11 may be arranged in the vehicle width direction to form an LED array, or they may be arranged in a matrix. Also, multiple light-emitting elements 11 may be arranged in the same direction or in different directions. If multiple light-emitting elements 11 are arranged in the same direction, the light emitted from the multiple light-emitting elements 11 can be guided in the same direction by a light guide member provided in the optical system. On the other hand, if multiple light-emitting elements 11 are arranged in different directions, the light emitted from the multiple light-emitting elements 11 can be guided in the same direction by a mirror unit provided in the optical system.

[0019] The lighting circuit 20 comprises a converter unit 21, a power control unit 22, a non-volatile memory unit 23, a power input terminal 24, a GND (ground) terminal 25, a lighting instruction signal input terminal 26, a temperature signal input terminal 27, and a circuit board 28. The power control unit 22 and the non-volatile memory unit 23 are mounted on an MCU (Microcontroller Unit) 29. This MCU 29, the converter unit 21, the power input terminal 24, the GND terminal 25, the lighting instruction signal input terminal 26, and the temperature signal input terminal 27 are mounted on the circuit board 28. The MCU 29 also stores a program for controlling the lighting of the light-emitting units 10A, 10B, 10C, and 10D.

[0020] The converter unit 21 includes multiple converters 21A, 21B, 21C, and 21D. Converter 21A is a DC / DC converter connected by a power line to the light-emitting unit 10A and the power input terminal 24, and converts the power supplied from the power input terminal 24 and outputs it to the light-emitting unit 10A. Converter 21B is a DC / DC converter connected by a power line to the light-emitting unit 10B and the power input terminal 24, and converts the power supplied from the power input terminal 24 and outputs it to the light-emitting unit 10B. Converter 21C is a DC / DC converter connected by a power line to the light-emitting unit 10C and the power input terminal 24, and converts the power supplied from the power input terminal 24 and outputs it to the light-emitting unit 10C. Converter 21D is a DC / DC converter connected by a power line to the light-emitting unit 10D and the power input terminal 24, and converts the power supplied from the power input terminal 24 and outputs it to the light-emitting unit 10D.

[0021] The power control unit 22 is connected by signal lines to a plurality of converters 21A, 21B, 21C, and 21D, a non-volatile memory unit 23, a lighting instruction signal input terminal 26, and a temperature signal input terminal 27. The power control unit 22 receives lighting instruction signals transmitted from a higher-level system installed in the vehicle. These lighting instruction signals are transmitted from the higher-level system for each function (lighting mode), such as high beams, daytime running lights, low beams, and turn signals and hazard lights. These lighting instruction signals include a high beam lighting instruction signal for light-emitting unit 10A, a daytime running light lighting instruction signal for light-emitting unit 10B, a low beam lighting instruction signal for light-emitting unit 10C, and turn signal and hazard light lighting instruction signals for light-emitting unit 10D.

[0022] In this case, the transmission timing of two or more illumination signal signals may overlap. For example, the transmission timing of the turn signal or hazard light illumination signal may overlap with the transmission timing of the high beam, daytime running light, and low beam illumination signal signals.

[0023] The non-volatile memory unit 23 stores control information used in the lighting control of the multiple light-emitting units 10A, 10B, 10C, and 10D. This control information includes map A, which is used in the temperature derating control of light-emitting unit 10A, which is responsible for the high beam function; map B, which is used in the temperature derating control of light-emitting unit 10B, which is responsible for the daytime running light function; map C, which is used in the temperature derating control of light-emitting unit 10C, which is responsible for the low beam function; and map D, which is used in the temperature derating control of light-emitting unit 10D, which is responsible for the turn signal and hazard light functions.

[0024] As will be explained in detail later, maps A, B, C, and D include as parameters the temperature signal (temperature information) received from the common temperature detection unit 30 and the relative values ​​of the output power of each converter 21A, 21B, 21C, and 21D. The relative values ​​of the output power of each converter 21A, 21B, 21C, and 21D are the ratio of output power to rated power (output power load factor) when temperature derating control is not being performed. That is, the relative values ​​of the output power of each converter 21A, 21B, 21C, and 21D when temperature derating control is not being performed are 100%. In contrast, the relative values ​​of the output power of each converter 21A, 21B, 21C, and 21D when temperature derating control is being performed are less than 100% (for example, 50-99%). The minimum value of the relative output power of each converter 21A, 21B, 21C, and 21D is preferably 30% or more, more preferably 40% or more, and even more preferably 50% or more.

[0025] When the power control unit 22 receives a lighting instruction signal for one or more functions from a higher-level system, it determines the relative output power of converters 21A, 21B, 21C, and 21D corresponding to the function for which the lighting instruction has been received, based on the temperature signal received from the temperature detection unit 30 and maps A, B, C, and D stored in the non-volatile memory unit 23. Specifically, when the power control unit 22 receives a lighting instruction signal for high beams from a higher-level system, it reads the relative output power of converter 21A corresponding to the temperature signal received from the temperature detection unit 30 from map A stored in the non-volatile memory unit 23. Also, when the power control unit 22 receives a lighting instruction signal for daytime running lights, it reads the relative output power of converter 21B corresponding to the temperature signal received from the temperature detection unit 30 from map B stored in the non-volatile memory unit 23. Furthermore, when the power control unit 22 receives a low beam illumination signal, it reads the relative output power of converter 21C corresponding to the temperature signal received from the temperature detection unit 30 from map C stored in the non-volatile memory unit 23. In addition, when the power control unit 22 receives a turn signal or hazard light illumination signal, it reads the relative output power of converter 21D corresponding to the temperature signal received from the temperature detection unit 30 from map D stored in the non-volatile memory unit 23. Then, the power control unit 22 transmits power signals A, B, C, and D to converters 21A, 21B, 21C, and 21D corresponding to the function that has received the illumination instruction, instructing them to use the calculated relative output power values.

[0026] Figures 3(A) to 3(D) are graphs showing the control characteristics for each function of the lighting unit 10 shown in Figure 2. Figure 3(A) is a graph showing the control characteristics for high beam lighting control, Figure 3(B) is a graph showing the control characteristics for daytime running light lighting control, Figure 3(C) is a graph showing the control characteristics for low beam lighting control, and Figure 3(D) is a graph showing the control characteristics for turn signal and hazard light lighting control.

[0027] As shown in these graphs, in the lighting control of any function of the lighting unit 10, in order to prevent overheating of the light-emitting element 11, temperature-dilating control is executed in accordance with the rise in temperature detected by the temperature detection unit 30. In this temperature-dilating control, when the temperature detected by the temperature detection unit 30 rises to a predetermined value, the relative value of the output power of each of the converters 21A, 21B, 21C, 21D decreases to a predetermined minimum value. Thereby, it is avoided that each light-emitting unit 10A, 10B, 10C, 10D is driven under the condition that the temperature of the light-emitting element 11 exceeds the upper limit temperature (the lightly shaded area in the upper right of each figure).

[0028] Here, the start temperature of the temperature-dilating control is set for each function. In the high-beam lighting control shown in FIG. 3(A), the start temperature of the temperature-dilating control is T3, and in the daytime lighting control shown in FIG. 3(B), the start temperature of the temperature-dilating control is T2 (<T3). Also, in the low-beam lighting control shown in FIG. 3(C), the start temperature of the temperature-dilating control is T5 (>T3), and in the lighting control of direction indication or hazard shown in FIG. 3(D), the start temperature of the temperature-dilating control is T3. Note that the start temperature of the above temperature-dilating control may be appropriately set according to the required performance of each function and the heat dissipation performance of each light-emitting unit 10A, 10B, 10C, 10D, etc.

[0029] The minimum value of the relative value of the output power of the converters 21A, 21B, 21C, 21D in the temperature-dilating control is set for each function. The minimum value of the relative value of the output power of the converter 21A in the high-beam temperature-dilating control shown in FIG. 3(A) is R A1 (for example, 50)%. When the high-beam temperature-dilating control is started, the relative value of the output power of the converter 21A decreases from 100% to R A2 %, R A1 %. Also, the minimum value of the relative value of the output power of the converter 21B in the daytime lighting temperature-dilating control shown in FIG. 3(B) is R B1(For example, 50)%. When the temperature dimming control for daytime lighting is started, the relative value of the output power of the converter 21B decreases from 100% to R B3 %, R B2 %, R B1 %. Also, the minimum value of the relative value of the output power of the converter 21C in the temperature dimming control of the low beam shown in Fig. 3(C) is R C1 (For example, 50)%. When the temperature dimming control of the low beam is started, the relative value of the output power of the converter 21C decreases from 100% to R C1 %. Furthermore, the minimum value of the relative value of the output power of the converter 21D in the temperature dimming control of the direction indicator and hazard shown in Fig. 3(D) is R D1 (>R A1 , R B1 , R C1 , for example, 75)%. When the temperature dimming control of the direction indicator and hazard is started, the relative value of the output power of the converter 21D decreases from 100% to R D2 %, R D1 %. Note that the minimum values of the relative values of the output powers of the converters 21A, 21B, 21C, and 21D in the temperature dimming control of each of the above functions may be appropriately set according to the required performance of each function and the heat dissipation performance of each light emitting unit 10A, 10B, 10C, and 10D.

[0030] In temperature derating control, the temperature at which the output power of converters 21A, 21B, 21C, and 21D ceases to decrease is set for each function. In the high beam temperature derating control shown in Figure 3(A), the temperature at which the output power of converter 21A ceases to decrease is T5. Similarly, in the daytime running light temperature derating control shown in Figure 3(B), the temperature at which the output power of converter 21B ceases to decrease is T5. Furthermore, in the low beam temperature derating control shown in Figure 3(C), the temperature at which the output power of converter 21C ceases to decrease is T6 (>T5). In addition, in the turn signal and hazard light temperature derating control shown in Figure 3(D), the temperature at which the output power of converter 21D ceases to decrease is T5. Note that the temperature at which the output power of converters 21A, 21B, 21C, and 21D ceases to decrease in the temperature derating control of each function should be set appropriately according to the required performance of each function and the heat dissipation performance of each light-emitting unit 10A, 10B, 10C, and 10D.

[0031] Map A is temperature derating information that associates temperatures T0 to T7 in Figure 3(A) with the relative output power of converter 21A at temperatures T0 to T7. Map B is temperature derating information that associates temperatures T0 to T7 in Figure 3(B) with the relative output power of converter 21B at temperatures T0 to T7. Map C is temperature derating information that associates temperatures T0 to T7 with the relative output power of converter 21C at temperatures T0 to T7. Furthermore, Map D is temperature derating information that associates temperatures T0 to T7 in Figure 3(D) with the relative output power of converter 21D at temperatures T0 to T7.

[0032] Figure 4 is a table showing the control characteristics for each function of the lighting unit 10 shown in Figure 2. This table shows the relationship between the relative values ​​of the output power of converters 21A, 21B, 21C, and 21D and the temperature detected by the temperature detection unit 30. This table shows the relative values ​​R of the output power of converters 21A, 21B, 21C, and 21D. A1 %, R A2 %, R B1 %, R B2%, R B3 %, R C1 %, R D1 %, R D2 This shows an example of percentages and temperatures T0~T7. In this example, the lowest starting temperature for temperature derating control is T2 for daytime running lights, while the highest starting temperature for temperature derating control is T5 for low beams. Also in this example, the highest minimum relative value of the output power of converters 21A, 21B, 21C, and 21D is at 75% for turn signals and hazard lights, while the lowest minimum value is at 50% for high beams, daytime running lights, and low beams. Furthermore, in this example, the highest temperature at which the output power decrease in temperature derating control ends is T6 for low beams, while the lowest temperature at which the output power decrease in temperature derating control ends is at T5 for high beams, daytime running lights, and turn signals and hazard lights.

[0033] Figure 5 is a schematic circuit diagram of a vehicle lighting device 101 according to a comparative example. Components similar to those in the vehicle lighting device 1 according to the above embodiment are denoted by the same reference numerals, and repeated explanations are omitted.

[0034] In the comparative example vehicle light fixture 101, the temperature detection unit 30 is mounted on the circuit board 28 of the lighting circuit 120 and detects the temperature of the lighting circuit 120. Furthermore, the lighting unit 110 of the comparative example vehicle light fixture 101 includes a light-emitting unit 10A for nighttime use and a light-emitting unit 10B for daytime use. That is, the lighting timings of light-emitting unit 10A and light-emitting unit 10B do not overlap.

[0035] Furthermore, in the vehicle lighting device 101 of the comparative example, the non-volatile memory unit 23 stores a map of temperature derating information for nighttime lighting and a map of temperature derating information for daytime lighting.

[0036] The power control unit 122 transmits power signals A and B to converters 21A and 21B based on the lighting instruction signals for the light-emitting units 10A and 10B received from the higher-level system, the temperature signal received from the temperature detection unit 30, and the maps of the light-emitting units 10A and 10B read from the non-volatile memory unit 23.

[0037] Specifically, when the power control unit 122 receives a signal from a higher-level system to turn on the night-time light-emitting unit 10A, it reads the relative value of the output power of the converter 21A corresponding to the temperature signal received from the temperature detection unit 30 from the night-time map stored in the non-volatile memory unit 23. The power control unit 122 then transmits a power signal A to the converter 21A indicating the calculated relative value of output power. Similarly, when the power control unit 122 receives a signal from a higher-level system to turn on the daytime light-emitting unit 10B, it reads the relative value of the output power of the converter 21B corresponding to the temperature signal received from the temperature detection unit 30 from the day-time map stored in the non-volatile memory unit 23. The power control unit 122 then transmits a power signal B to the converter 21B indicating the calculated relative value of output power.

[0038] In the comparative example vehicle light fixture 101, the lighting timings of the nighttime light-emitting unit 10A and the daytime light-emitting unit 10B do not overlap. Therefore, the temperature detected by the temperature detection unit 30 in the lighting circuit 120 becomes a temperature corresponding to the heat generated by the nighttime light-emitting unit 10A when the nighttime light-emitting unit 10A is lit, and a temperature corresponding to the heat generated by the daytime light-emitting unit 10B when the daytime light-emitting unit 10B is lit.

[0039] Figure 6 is a graph showing the control characteristics of the nighttime light-emitting unit 10A and the daytime light-emitting unit 10B shown in Figure 5. In the graph in Figure 6, the control characteristics of the nighttime light-emitting unit 10A are shown with a solid line, and the control characteristics of the daytime light-emitting unit 10B are shown with a dashed line. As shown in this graph, the temperature derating control of the nighttime light-emitting unit 10A is prevented from being executed under conditions where the upper limit temperatures of both light-emitting units 10A and 10B are exceeded (thinly colored areas A and B in the figure). In addition, the temperature derating control of the nighttime light-emitting unit 10A starts from the assumed temperature. Similarly, the temperature derating control of the daytime light-emitting unit 10B is prevented from being executed under conditions where the upper limit temperature of light-emitting unit 10B is exceeded (thinly colored area B in the figure). In addition, the temperature derating control of the daytime light-emitting unit 10B starts from the assumed temperature.

[0040] In other words, if the lighting timings of the nighttime light-emitting unit 10A and the daytime light-emitting unit 10B do not overlap, the temperature derating control of the light-emitting units 10A and 10B can be performed without problems based on the temperature of the lighting circuit 120. On the other hand, if the lighting timings of multiple light-emitting units overlap, performing the temperature derating control of those multiple light-emitting units based on the temperature of the lighting circuit 120 may result in the suppression of output power starting from an unexpected temperature. This point will be explained below.

[0041] Figure 7 is a schematic circuit diagram of a vehicle lighting device 201 according to a comparative example. Components similar to those in the vehicle lighting device 101 of the comparative example are denoted by the same reference numerals, and repeated explanations are omitted.

[0042] The lighting unit 210 of the vehicle lighting device 201 in the comparative example includes a light-emitting unit 10A for nighttime use, a light-emitting unit 10B for daytime use, and a light-emitting unit 10C that is common to both day and night. That is, the lighting timing of light-emitting unit 10A and light-emitting unit 10C may overlap. Also, the lighting timing of light-emitting unit 10B and light-emitting unit 10C may overlap.

[0043] Furthermore, in the vehicle lighting device 201 of the comparative example, the non-volatile memory unit 23 stores a map of temperature derating information for nighttime lighting and a map of temperature derating information for daytime lighting.

[0044] In the comparative example vehicle lighting device 201, the temperature detection unit 30 is mounted on the circuit board 28 of the lighting circuit 220 and detects the temperature of the lighting circuit 220. In addition, converters 21A, 21B, and 21C are provided in the converter section 21 of the lighting circuit 220.

[0045] Here, the power control unit 222 transmits power signals A, B, and C to the converters 21A, 21B, and 21C based on the lighting instruction signals for the light-emitting units 10A, 10B, and 10C received from the higher-level system, the temperature signal received from the temperature detection unit 30, and the map stored in the non-volatile memory unit 23.

[0046] Specifically, when the power control unit 222 receives a signal from a higher-level system to turn on the night-time light-emitting unit 10A, it reads the relative value of the output power of the converter 21A corresponding to the temperature signal received from the temperature detection unit 30 from the night-time map stored in the non-volatile memory unit 23. The power control unit 222 then transmits a power signal A to the converter 21A indicating the calculated relative value of output power. Similarly, when the power control unit 222 receives a signal from a higher-level system to turn on the daytime light-emitting unit 10B, it reads the relative value of the output power of the converter 21B corresponding to the temperature signal received from the temperature detection unit 30 from the day-time map stored in the non-volatile memory unit 23. The power control unit 222 then transmits a power signal B to the converter 21B indicating the calculated relative value of output power.

[0047] On the other hand, when the power control unit 222 receives a lighting instruction signal for the light-emitting units 10A and 10C from a higher-level system, it reads the relative values ​​of the output power of the converters 21A and 21C corresponding to the temperature signal received from the temperature detection unit 30 from the night map stored in the non-volatile memory unit 23. Then, the power control unit 222 transmits power signals A and C to the converters 21A and 21C, instructing them to use the calculated relative values ​​of output power.

[0048] Furthermore, when the power control unit 222 receives a lighting instruction signal for the light-emitting units 10B and 10C from a higher-level system, it reads the relative values ​​of the output power of the converters 21B and 21C corresponding to the temperature signal received from the temperature detection unit 30 from map B stored in the non-volatile memory unit 23. The power control unit 222 then transmits power signals B and C to the converters 21B and 21C, instructing them to use the calculated relative values ​​of output power.

[0049] In the comparative example vehicle lighting device 201, the lighting timings of the night-time light-emitting unit 10A and the day / night common light-emitting unit 10C may overlap. Also, the lighting timings of the daytime light-emitting unit 10B and the day / night common light-emitting unit 10C may overlap. Therefore, the temperature detected by the temperature detection unit 30 in the lighting circuit 220 will not be the temperature corresponding to the heat generated by the night-time light-emitting unit 10A when the light-emitting units 10A and 10C are lit, but will be the temperature corresponding to the heat generated by the light-emitting units 10A and 10C. In other words, the temperature derating control of the night-time light-emitting unit 10A is affected by the heat generated when the day / night common light-emitting unit 10C is lit.

[0050] Similarly, the temperature detected by the temperature detection unit 30 in the lighting circuit 220 does not become the temperature corresponding to the heat generated by the daytime light-emitting unit 10B when the light-emitting units 10B and 10C are lit, but rather the temperature corresponding to the heat generated by the light-emitting units 10B and 10C. In other words, the temperature derating control of the daytime light-emitting unit 10B is affected by the heat generated when the daytime light-emitting unit 10C, which is common to both day and night, is lit.

[0051] Figure 8 is a graph showing the control characteristics of the nighttime light-emitting unit 10A shown in Figure 7. In the graph of Figure 8, the control characteristics of the nighttime light-emitting unit 10A when the daytime light-emitting unit 10C is not lit are shown with a solid line, and the control characteristics of the nighttime light-emitting unit 10A when the daytime light-emitting unit 10C is lit are shown with a dashed line. As shown in this graph, when the daytime light-emitting unit 10C is not lit, the temperature derating control of the nighttime light-emitting unit 10A is avoided when the nighttime light-emitting unit 10A exceeds the upper limit temperature (lightly shaded area A in the figure). In addition, the temperature derating control of the nighttime light-emitting unit 10A starts from the assumed temperature.

[0052] In contrast, as shown by the dashed line in the diagram, when the daytime and nighttime light-emitting unit 10C is lit, the temperature derating control of the nighttime light-emitting unit 10A is prevented from being executed under conditions that exceed the upper temperature limit, but it starts from an unexpectedly low temperature. In this case, even at the normal operating temperature of the nighttime light-emitting unit 10A (a temperature that does not exceed the upper temperature limit), the output power of the converter 21A is suppressed, and the amount of light emitted by the nighttime light-emitting unit 10A is suppressed, which may impair the performance required for the nighttime lighting function, which is to ensure visibility at night.

[0053] Similarly, when the daytime light-emitting unit 10B and the daytime / nighttime light-emitting unit 10C are illuminated simultaneously, the temperature derating control of the daytime light-emitting unit 10B may start at an unexpectedly low temperature. In this case, even at the normal operating temperature of the daytime light-emitting unit 10B (a temperature not exceeding the upper limit), the output power of the converter 21B is suppressed, and the amount of light emitted by the daytime light-emitting unit 10B is suppressed. This may impair the performance required for the daytime lighting function, which is to make it clear that the vehicle is in motion during the day.

[0054] Figure 9 is a schematic circuit diagram of a vehicle lighting device 301 according to the comparative example. Components similar to those in the vehicle lighting device 201 of the comparative example are denoted by the same reference numerals, and repeated explanations are omitted.

[0055] The lighting unit 310 of the vehicle lighting device 301 in the comparative example comprises a light-emitting unit 10A for nighttime use, a light-emitting unit 10B for daytime use, and a light-emitting unit 10C that is common to both day and night. The vehicle lighting device 301 in the comparative example also comprises temperature detection units 30A, 30B, and 30C.

[0056] The temperature detection unit 30A is located inside the night-time light-emitting unit 10A and detects the internal temperature of the night-time light-emitting unit 10A, transmitting a temperature signal A to the power control unit 322. The temperature detection unit 30B is located inside the day-time light-emitting unit 10B and detects the internal temperature of the day-time light-emitting unit 10B, transmitting a temperature signal B to the power control unit 322. Furthermore, the temperature detection unit 30C is located inside the day and night common light-emitting unit 10C and detects the internal temperature of the light-emitting unit 10C, transmitting a temperature signal C to the power control unit 322.

[0057] The power control unit 322 transmits power signals A, B, C to converters 21A, 21B, and 21C based on the lighting instruction signals for the light-emitting units 10A, 10B, and 10C received from the higher-level system, the temperature signals A, B, and C received from the temperature detection units 30A, 30B, and 30C, and the temperature derating information maps A, B, and C for the light-emitting units 10A, 10B, and 10C stored in the non-volatile memory unit 23.

[0058] Specifically, when the power control unit 322 receives a signal from a higher-level system to turn on the night-time light-emitting unit 10A, it reads the relative value of the output power of the converter 21A corresponding to the temperature signal A received from the temperature detection unit 30A from map A stored in the non-volatile memory unit 23. The power control unit 322 then transmits a power signal A to the converter 21A indicating the calculated relative value of the output power. Similarly, when the power control unit 322 receives a signal from a higher-level system to turn on the daytime light-emitting unit 10B, it reads the relative value of the output power of the converter 21B corresponding to the temperature signal B received from the temperature detection unit 30B from map B stored in the non-volatile memory unit 23. The power control unit 322 then transmits a power signal B to the converter 21B indicating the calculated relative value of the output power. Furthermore, when the power control unit 322 receives a lighting instruction signal for the light-emitting unit 10C, which is common day and night, from a higher-level system, it reads the relative value of the output power of the converter 21C corresponding to the temperature signal C received from the temperature detection unit 30C from the map C stored in the non-volatile memory unit 23. Then, the power control unit 322 transmits a power signal C indicating the calculated relative value of the output power to the converter 21C.

[0059] On the other hand, when the power control unit 322 receives a lighting instruction signal for the light-emitting units 10A and 10C from a higher-level system, it reads the relative value of the output power of the converter 21A corresponding to the temperature signal A received from the temperature detection unit 30A from map A stored in the non-volatile memory unit 23. At the same time, the power control unit 322 also reads the relative value of the output power of the converter 21C corresponding to the temperature signal C received from the temperature detection unit 30C from map C stored in the non-volatile memory unit 23. The power control unit 322 then transmits power signals A and C, which indicate the relative values ​​of the output power obtained, to the converters 21A and 21C.

[0060] Furthermore, when the power control unit 322 receives a lighting instruction signal for the light-emitting units 10B and 10C from a higher-level system, it reads the relative value of the output power of the converter 21B corresponding to the temperature signal B received from the temperature detection unit 30B from map B stored in the non-volatile memory unit 23. At the same time, the power control unit 322 also reads the relative value of the output power of the converter 21C corresponding to the temperature signal C received from the temperature detection unit 30C from map C stored in the non-volatile memory unit 23. Then, the power control unit 322 transmits power signals B and C, which indicate the obtained relative values ​​of output power, to the converters 21B and 21C.

[0061] In the vehicle lighting device 301 of the comparative example, when the lighting timings of the night-time light-emitting unit 10A and the day / night common light-emitting unit 10C overlap, the temperature detection unit 30A detects the internal temperature of the night-time light-emitting unit 10A, and the temperature detection unit 30C detects the internal temperature of the day / night common light-emitting unit 10C. Therefore, the temperature derating control of the night-time light-emitting unit 10A is not affected by the heat generated when the day / night common light-emitting unit 10C is lit. Similarly, when the lighting timings of the day-time light-emitting unit 10B and the day / night common light-emitting unit 10C overlap, the temperature detection unit 30B detects the internal temperature of the day-time light-emitting unit 10B, and the temperature detection unit 30C detects the internal temperature of the day / night common light-emitting unit 10C. Therefore, the temperature derating control of the day-time light-emitting unit 10B is not affected by the heat generated when the day / night common light-emitting unit 10C is lit.

[0062] However, in the comparative example vehicle lighting device 301, the number of temperature detection elements constituting the temperature detection units 30A, 30B, and 30C, the wiring for connection, the input circuit of the power control unit 322, the input terminals of the power control unit 322, and the temperature signal input terminals 27 of the lighting circuit 320 are increased compared to the case where there is only one temperature detection unit 30.

[0063] In contrast, the vehicle lighting fixture 1 according to this embodiment performs temperature derating control based on the temperature inside the lamp chamber 2 detected by a single temperature detection unit 30. Therefore, compared to the vehicle lighting fixture 301 according to the comparative example, the number of temperature detection elements constituting the temperature detection unit 30, connection wiring, input circuits for the power control unit 22, input terminals for the power control unit 22, and temperature signal input terminals 27 for the lighting circuit 20 can be reduced. Thus, costs can be reduced compared to the vehicle lighting fixture 301 according to the comparative example.

[0064] Furthermore, in the vehicle lighting device 1 according to this embodiment, a plurality of temperature derating information, defined by the ambient temperature inside the lamp chamber 2 and the power input to the lighting device 10 for each lighting mode of the lighting device 10, is stored in the non-volatile memory unit 23. The power control unit 22 then controls the power input to the lighting device 10 according to the lighting mode of the lighting device 10, the ambient temperature inside the lamp chamber 2 detected by the temperature detection unit 30, and the temperature derating information stored in the non-volatile memory unit 23. As a result, if the lighting mode of the lighting device 10 is high beam, temperature derating control is performed according to the performance required for high beam, and so on, allowing temperature derating control to be performed without hindrance while satisfying the requirements for each lighting mode of the lighting device 10.

[0065] In the vehicle lighting device 1 according to this embodiment, the area inside the lamp chamber 2 where the ambient temperature is detected by the temperature detection unit 30 is an area that is less affected by the heat generated when the lighting unit 10 is lit. As a result, when the lighting timings of multiple lighting modes overlap, such as when the turn signals are lit when the high beams are lit, the temperature derating control of the light-emitting unit responsible for one lighting mode can be performed without being affected by the heat generated when the light-emitting unit responsible for the other lighting mode is lit. Furthermore, when the lighting timings of multiple lighting modes overlap, temperature derating control can be performed without hindrance for both the light-emitting unit responsible for one lighting mode and the light-emitting unit responsible for the other lighting mode, while satisfying the required performance.

[0066] Furthermore, in the vehicle lighting device 1 according to this embodiment, the load factor of the power input to the light-emitting unit 10D for the turn signals and hazard lights, which are among the multiple lighting modes of the lighting unit 10, is set higher than that for other lighting modes such as high beams. As a result, the decrease in the amount of light emitted due to temperature derading control is relatively suppressed for the light-emitting unit 10D that is responsible for the turn signals and hazard lights. Therefore, it becomes possible to ensure the visibility required for the turn signals and hazard lights even while temperature derading control is being performed.

[0067] Here, the low beam is the lighting mode used when passing an oncoming vehicle while driving at night. Therefore, the light-emitting unit 10C responsible for the low beam is required to have a relatively high starting temperature for temperature derating control. Accordingly, in the vehicle lighting device 1 according to this embodiment, the starting temperature for temperature derating control for the low beam, one of the multiple lighting modes of the lighting unit 10, is set higher than that for other lighting modes such as the high beam.

[0068] Furthermore, daytime lighting is a lighting mode designed to make it clear to those around the vehicle that it is in motion during daylight hours. Therefore, the light-emitting unit 10B, which is responsible for daytime lighting, only needs to illuminate in a way that allows the surroundings to perceive its presence while driving. Here, since the temperature detection area of ​​the temperature detection unit 30 is cooled by the airflow while driving, the light-emitting unit 10C, which is responsible for daytime lighting, is not required to set a relatively high starting temperature for temperature derating control. Therefore, For daytime lighting, one of the multiple lighting modes of the lighting unit 10, the starting temperature for temperature derading control is set lower than that for other lighting modes such as high beam. This makes it possible to lower the required level of heat dissipation performance of the light-emitting unit 10C.

[0069] Figure 10 is a schematic side cross-sectional view of a vehicle light fixture 1A according to another embodiment of the present invention. As shown in this figure, in the vehicle light fixture 1A according to this embodiment, the temperature detection unit 30 is located on the outer surface of the body 40 and detects the temperature around the light chamber 2.

[0070] Here, the ambient temperature below the lamp chamber 2 is lower than the ambient temperature above the lamp chamber 2, and is less affected by the heat generated by the lighting unit 10. Therefore, in the vehicle lighting device 1A according to this embodiment, the temperature detection unit 30 is placed on the bottom surface of the body 40, and the ambient temperature below the lamp chamber 2 is detected by the temperature detection unit 30. As a result, when the lighting timings of multiple lighting modes overlap, such as when the turn signals are lit when the high beams are lit, the temperature derating control of the light-emitting unit responsible for one lighting mode can be performed without being affected by the heat generated when the light-emitting unit responsible for the other lighting mode is lit.

[0071] Figure 11 is a schematic side cross-sectional view of a vehicle light fixture 1B according to another embodiment of the present invention. As shown in this figure, in the vehicle light fixture 1B according to this embodiment, the temperature detection unit 30 is located below the lighting unit 10 and detects the temperature inside the light chamber 2.

[0072] In this embodiment, the vehicle lighting device 1B is designed so that heat flow does not occur in the area below the lighting unit 10. The ambient temperature below the lighting unit 10 is lower than the ambient temperature above the lighting unit 10, making it less susceptible to the heat generated when the lighting unit 10 is lit. Therefore, in the vehicle lighting device 1B according to this embodiment, the temperature detection unit 30 is located below the lighting unit 10, and the ambient temperature below the lighting unit 10 is detected by the temperature detection unit 30. This allows for temperature derating control of the light-emitting unit responsible for one lighting mode to be performed without being affected by the heat generated when the light-emitting unit responsible for the other lighting mode is lit, even when the lighting timings of multiple lighting modes overlap, such as when the turn signals are lit when the high beams are lit.

[0073] Although the present invention has been described above based on the above embodiments, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the invention, or the technologies of the embodiments or publicly known technologies may be combined.

[0074] For example, in the above embodiment, a plurality of temperature derating information defined by the internal or ambient temperature of the lamp chamber 2 and the relative value of the power input to the lighting unit 10 is stored in the non-volatile memory unit 23. Then, in the above embodiment, the relative value of the power input to the lighting unit 10 is controlled according to the lighting mode of the lighting unit 10, the internal or ambient temperature of the lamp chamber 2 detected by the temperature detection unit 30, and the temperature derating information stored in the non-volatile memory unit 23. However, the relative value of power may be replaced with the absolute value of power, or power may be replaced with electric current.

[0075] Furthermore, in the above embodiment, the power control unit 22 and the non-volatile memory unit 23 are provided in the lighting circuit 20 of the vehicle lighting fixtures 1, 1A, and 1B. However, at least one of the power control unit 22 and the non-volatile memory unit 23 may be provided in the vehicle system.

[0076] Furthermore, in the above embodiment, the multiple temperature derating information is generated considering the required performance of each lighting mode of the lighting unit 10 and the heat dissipation performance of each light-emitting unit 10A, 10B, 10C, 10D, and stored in the non-volatile memory unit 23, and no further updates are performed. However, the multiple temperature derating information may be made updatable through the vehicle's system. In this case, the latest program can be installed on the MCU 29 through the vehicle's system. Furthermore, the MCU 29 can be made to execute the procedure for storing the latest multiple temperature derating information in the non-volatile memory unit 23 and the procedure for controlling the output power of the converter unit 21 based on the updated multiple temperature derating information using the updated program. [Explanation of symbols]

[0077] 1: Vehicle lighting fixtures 1A: Vehicle lighting fixtures 1B: Vehicle lighting fixtures 2:Lamp room 10: Lighting part 10A: Light-emitting unit 10B: Light-emitting unit 10C: Light-emitting unit 10D: Light-emitting unit 11: Light-emitting element 21A: Converter 21B: Converter 21C: Converter 21D: Converter 22: Power Control Unit (Control Unit) 23: Non-volatile memory section (storage section) 29: MCU (Control Unit) 30: Temperature detection unit

Claims

1. A control device for a vehicle lighting device that performs temperature derating control of a vehicle lighting device comprising a lighting unit that lights up in multiple lighting modes and a temperature detection unit that detects the ambient temperature around the lighting chamber, A storage unit that stores a plurality of temperature derating information defined by the ambient temperature around the lamp chamber and the power or current input to the lighting unit for each lighting mode of the lighting unit, A control unit controls the power or current input to the lighting unit according to the lighting mode of the lighting unit, the ambient temperature around the lamp chamber detected by the temperature detection unit, and the temperature derating information stored in the storage unit. A control device for vehicle lighting equipment, comprising the following:

2. The control device for a vehicle lighting device according to claim 1, wherein the area surrounding the lighting chamber where the ambient temperature is detected by the temperature detection unit is the lower area of ​​the lighting chamber which is less affected by the heat generated by the lighting unit.

3. The control device for a vehicle lighting device according to claim 1, wherein at least two of the multiple lighting modes may have overlapping lighting timings.

4. A control device for a vehicle lighting device according to claim 1, wherein at least one of the plurality of lighting modes has a different load factor of power or current input to the lighting unit compared to the other lighting modes.

5. The control device for a vehicle lamp according to claim 1, wherein at least one of the plurality of lighting modes has a starting temperature for the temperature derating control that differs from that of the other lighting modes.

6. The control device for a vehicle lighting device according to claim 1, wherein the plurality of lighting modes include high beam, low beam, daytime running lights, and turn signals.

7. The aforementioned lighting unit comprises a plurality of light-emitting units, The light-emitting unit corresponds to one or more of the aforementioned lighting modes, and is a control device for a vehicle lighting device according to claim 1.

8. A lighting unit that lights up in multiple lighting modes, One temperature detection unit detects the ambient temperature around the lamp chamber, A control device that performs temperature derating control of the lighting unit and A vehicle lighting fixture equipped with, The control device is A storage unit that stores a plurality of temperature derating information defined by the ambient temperature around the lamp chamber and the power or current input to the lighting unit for each lighting mode of the lighting unit, A control unit controls the power or current input to the lighting unit according to the lighting mode of the lighting unit, the ambient temperature around the lamp chamber detected by the temperature detection unit, and the temperature derating information stored in the storage unit. A vehicle light fixture equipped with [a specific feature / feature].

9. A program for causing a control device to perform temperature derating control on a vehicle lighting device comprising a lighting unit that illuminates in multiple lighting modes and a temperature detection unit that detects the ambient temperature around the lighting chamber, A procedure for storing a plurality of temperature derating information in a storage unit for each lighting mode of the lighting unit, which is defined by the ambient temperature around the lamp chamber and the power or current input to the lighting unit. A procedure for controlling the power or current input to the lighting unit according to the lighting mode of the lighting unit, the ambient temperature around the lighting chamber detected by the temperature detection unit, and the temperature derating information stored in the storage unit. A program that causes the control device to execute the following.

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