Headlamp device

Abstract

To provide a headlamp device capable of mitigating a high temperature state of a high beam while ensuring brightness in front of a vehicle with the high beam.SOLUTION: A headlamp device 1 includes: a headlamp 3 having a high beam irradiation unit 5 that irradiates a main high beam and a high beam irradiation unit 6 that irradiates a sub-high beam; a temperature sensor 9 that detects the temperature of the main high beam; and a control ECU 11 that controls the high beam irradiation units 5, 6 so that, when the temperature of the main high beam detected by the temperature sensor 9 is equal to or higher than a predetermined specified temperature, the output light amount of the main high beam is reduced and the output light amount of the sub-high beam compensates for the reduction in the output light amount of the main high beam.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a headlamp device. [Background technology]

[0002] As a conventional headlamp device, for example, the technology described in Patent Document 1 is known. The headlamp device described in Patent Document 1 is a vehicle lamp having functions such as low beam and high beam. The vehicle lamp includes a light source configured with a semiconductor light emitting element, a temperature sensor that detects the temperature of the light source, and a lamp control module that controls the light source. The lamp control module includes a signal processing device that calculates a current value after temperature derating for the detection value of the temperature sensor, and a drive circuit that generates a drive current according to the current value after temperature derating and supplies the drive current to the light source. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-49514 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technology has the following problems. That is, when a temperature rise of the light source is detected by the temperature sensor, the current value after temperature derating is reduced due to the temperature derating characteristic, and the drive current supplied to the light source is reduced. Therefore, the light emitted from the light source is dimmed, and the brightness in front of the vehicle is reduced. In particular, dimming the high beam has a significant impact on night driving.

[0005] An object of the present invention is to provide a headlamp device capable of mitigating high temperature conditions of the high beams while ensuring brightness in front of the vehicle through the high beams. [Means for solving the problem]

[0006] A headlamp device according to one aspect of the present invention includes a headlamp having a first high beam irradiation unit that irradiates a first high beam and a second high beam irradiation unit that irradiates a second high beam; a temperature detection unit that detects the temperature of the first high beam; and a control unit that controls the first high beam irradiation unit and the second high beam irradiation unit to reduce the output light amount of the first high beam and to increase the output light amount of the second high beam to compensate for the reduction in the output light amount of the first high beam when the temperature of the first high beam detected by the temperature detection unit is equal to or higher than a predetermined specified temperature. Effect of the Invention

[0007] According to the present invention, it is possible to alleviate the high temperature state of the high beam while ensuring the brightness of the area ahead of the vehicle through the high beam. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a configuration of a headlamp device according to an embodiment of the present invention; [Diagram 2] 2 is a flowchart showing a procedure of a control process executed by a control ECU shown in FIG. 1. [Diagram 3] 1A to 1C are conceptual diagrams showing images of light distribution patterns in a basic state, a high temperature state, and a light-blocking state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] Fig. 1 is a block diagram showing the configuration of a headlamp device according to one embodiment of the present invention, in which a headlamp device 1 of the present embodiment is mounted on a vehicle 2 such as an automobile.

[0011] The headlamp device 1 includes a headlamp 3 attached to the front end of a vehicle 2. The headlamp 3 includes a low beam irradiation unit 4 that irradiates a low beam toward the front of the vehicle 2, and high beam irradiation units 5 and 6 that irradiate a high beam toward the front of the vehicle 2.

[0012] Although not shown in the figure, the low beam irradiation unit 4 and the high beam irradiation units 5 and 6 are arranged side by side in the vehicle width direction of the vehicle 2. The high beam irradiation unit 5 constitutes a first high beam irradiation unit that irradiates a main high beam, which is a first high beam. The high beam irradiation unit 6 constitutes a second high beam irradiation unit that irradiates a sub-high beam, which is a second high beam. Note that the high beam irradiation unit 6 may irradiate the main high beam, and the high beam irradiation unit 5 may irradiate the sub-high beam.

[0013] The low beam irradiation unit 4 and the high beam irradiation units 5 and 6 are each composed of a dedicated lamp. The lamp is composed of multiple LEDs (light emitting diodes). By independently controlling the light emission amount of each LED, it is possible to partially adjust the output light amount of the low beam, main high beam, and sub-high beam.

[0014] The headlamp device 1 also includes a camera 7, a headlamp switch 8, temperature sensors 9 and 10, and a control ECU (Electronic Control Unit) 11.

[0015] The camera 7 captures an image of the area ahead of the vehicle 2 and outputs the captured image. The headlamp switch 8 is a switch that the driver of the vehicle 2 manually operates to turn on / off and switch between low beam and high beam.

[0016] The temperature sensor 9 is a sensor that detects the temperature of the high beam irradiated from the high beam irradiator 5. The temperature sensor 9 detects, for example, the temperature of the high beam irradiator 5 itself. The temperature sensor 9 constitutes a temperature detection unit that detects the temperature of the main high beam. The temperature sensor 10 is a sensor that detects the temperature of the high beam irradiated from the high beam irradiator 6. The temperature sensor 10 detects, for example, the temperature of the high beam irradiator 6 itself.

[0017] The control ECU 11 is an electronic control unit having a CPU, RAM, ROM, an input / output interface, etc. The control ECU 11 performs various control functions including a headlamp control function by, for example, loading a program recorded in the ROM into the RAM and executing the program loaded into the RAM by the CPU. The control ECU 11 may be composed of multiple electronic units.

[0018] The control ECU 11 executes a predetermined process based on image data from the camera 7, an operation signal from a headlamp switch 8, and detection values ​​from temperature sensors 9 and 10, and controls the low beam irradiation unit 4 and the high beam irradiation units 5 and 6.

[0019] The control ECU 11 has a scene determination unit 12, a light distribution determination unit 13, and an output control unit .

[0020] The scene determination unit 12 determines the state of the vehicle 2 and the scene ahead of the vehicle 2 based on image data from the camera 7, an operation signal from the headlamp switch 8, and detection values ​​from the temperature sensors 9 and .

[0021] The light distribution determination unit 13 determines the light distribution pattern of the headlamp 3 based on the result of the determination by the scene determination unit 12.

[0022] The output control unit 14 controls the low beam irradiating unit 4 and the high beam irradiating units 5 and 6 of the headlamp 3 according to the light distribution pattern of the headlamp 3 determined by the light distribution determining unit 13 .

[0023] The control ECU 11 constitutes a control unit that, when the temperature of the main high beam detected by the temperature sensor 9 is equal to or higher than a predetermined specified temperature, reduces the output light amount of the main high beam and controls the high beam irradiation units 5, 6 so that the output light amount of the sub-high beam compensates for the reduction in the output light amount of the main high beam.

[0024] Fig. 2 is a flowchart showing the procedure of the control process executed by the control ECU 11. In Fig. 2, the control ECU 11 first determines whether or not the high beam has been turned on by the headlamp switch 8 (step S100).

[0025] When the control ECU 11 determines that the high beams have been turned on, it controls the headlamps 3 to implement a basic light distribution pattern as the light distribution pattern (step S101). As shown in Fig. 3(a), the basic light distribution pattern includes a normal light distribution pattern and a high-intensity light distribution pattern. The normal light distribution pattern is a light distribution pattern that irradiates only the main high beam and does not irradiate the sub-high beam. The high-intensity light distribution pattern is a light distribution pattern that irradiates both the main high beam and the sub-high beam.

[0026] When implementing a normal light distribution pattern, the control ECU 11 outputs a power signal corresponding to the normal light distribution pattern to the high beam irradiation unit 5. When implementing a high-intensity light distribution pattern, the control ECU 11 outputs a power signal corresponding to the high-intensity light distribution pattern to the high beam irradiation units 5 and 6.

[0027] Next, the control ECU 11 determines whether the main high beam irradiated from the high beam irradiator 5 is in a high temperature state based on the detection value of the temperature sensor 9 (step S102). The control ECU 11 determines that the main high beam is in a high temperature state when the temperature of the main high beam is a predetermined specified temperature.

[0028] When the control ECU 11 determines that the main high beam is not in a high temperature state, the control ECU 11 maintains the basic light distribution pattern as the light distribution pattern (step S103). Then, the control ECU 11 controls the headlamp 3 to implement the basic light distribution pattern (step S104).

[0029] When the control ECU 11 determines that the main high beam is in a high temperature state, it determines whether the main high beam was not in a high temperature state in the previous cycle (step S105).When the control ECU 11 determines that the main high beam was not in a high temperature state in the previous cycle, it determines whether the sub-high beam is not turned on (step S106).

[0030] When the control ECU 11 determines that the sub-high beam is not on, it switches the light distribution pattern to a high temperature light distribution pattern in which the main high beam is dimmed and the sub-high beam is turned on (step S107). At this time, the light emission amount of all LEDs of the high beam irradiation unit 5 is reduced to dim the main high beam.

[0031] When the control ECU 11 determines that the sub-high beam is on, it switches the light distribution pattern to a high temperature light distribution pattern in which the main high beam is dimmed and the sub-high beam is dimmed (step S108). At this time, the light emission amount of all LEDs of the high beam irradiation units 5 and 6 is reduced, so that the main high beam and the sub-high beam are dimmed.

[0032] The high temperature light distribution pattern is a light distribution pattern in which the output light amount of the main high beam is lower than that of the basic light distribution pattern, and the output light amount of the sub-high beam is an amount of light equivalent to the decrease in the output light amount of the main high beam, as shown in Fig. 3(b). At this time, for example, by using a light distribution map showing the relationship between the temperature of the main high beam and the output light amount of the main high beam, the output light amounts of the main high beam and the sub-high beam that will keep the main high beam at a safe temperature can be obtained.

[0033] After executing step S107 or step S108, the control ECU 11 controls the high beam irradiation units 5 and 6 of the headlamp 3 to implement the high temperature light distribution pattern (step S109). At this time, the control ECU 11 outputs a power signal corresponding to the high temperature light distribution pattern to the high beam irradiation units 5 and 6.

[0034] When the control ECU 11 determines in step S105 that the main high beam was in a high temperature state in the previous cycle, it determines based on the image data from the camera 7 whether or not a preceding vehicle (see Figure 3(c)) is present in front of the vehicle 2 (step S110).

[0035] When the control ECU 11 determines that there is no preceding vehicle ahead of the vehicle 2, it maintains the high temperature light distribution pattern (step S111). Then, the control ECU 11 controls the high beam irradiation units 5 and 6 of the headlamp 3 to implement the high temperature light distribution pattern (step S109).

[0036] When the control ECU 11 determines that a preceding vehicle is present ahead of the vehicle 2, it switches the light distribution pattern to a light distribution pattern during shading that shades the preceding vehicle (step S112). The light distribution pattern during shading is a light distribution pattern in which the main high beam is irradiated ahead of the vehicle 2 to avoid the preceding vehicle and the sub-high beam is turned off, as shown in Fig. 3(c). In the light distribution pattern during shading, the output light amount of the main high beam is equal to the output light amount of the normal light distribution pattern described above.

[0037] Then, the control ECU 11 controls the high beam irradiation units 5 and 6 of the headlamps 3 to implement the light distribution pattern during shading (step S113). At this time, the shading of the preceding vehicle is performed by turning off the LEDs in the high beam irradiation unit 5 that correspond to the preceding vehicle.

[0038] After executing any one of steps S104, S109, and S113, the control ECU 11 judges whether the high beam has been turned off by the headlamp switch 8 (step S114). If the control ECU 11 judges that the high beam has not been turned off, it executes the above-mentioned step S102 again. If the control ECU 11 judges that the high beam has been turned off, it ends this process.

[0039] Here, the scene determination unit 12 executes steps S100, S102, S105, S106, S110, and S114. The light distribution determination unit 13 executes steps S103, S107, S108, S111, and S112. The output control unit 14 executes steps S101, S104, S109, and S113.

[0040] In the headlamp device 1 as described above, when the high beam is turned on by the headlamp switch 8, the basic light distribution pattern is implemented in the basic state as shown in FIG. 3(a).

[0041] Specifically, under normal circumstances, a normal light distribution pattern is implemented in which the high beam irradiation unit 5 irradiates a main high beam, but the high beam irradiation unit 6 does not irradiate a sub-high beam. When a high amount of light (high luminous intensity) is required, such as when driving at high speed, a high luminous intensity light distribution pattern is implemented in which the high beam irradiation unit 5 irradiates a main high beam, and the high beam irradiation unit 6 irradiates a sub-high beam.

[0042] In a high temperature state where the temperature of the main high beam is equal to or higher than a specified temperature, as shown in Fig. 3(b), a high temperature light distribution pattern is implemented in which the main high beam is irradiated from the high beam irradiator 5 and the sub-high beam is irradiated from the high beam irradiator 6. At this time, the output light amount of the main high beam is lower than the output light amount of the main high beam in the basic light distribution pattern. The output light amount of the sub-high beam is an amount of light equivalent to the decrease in the output light amount of the main high beam. Therefore, the combined output light amount of the main high beam and the sub-high beam is equal to the output light amount of the main high beam in the normal light distribution pattern.

[0043] In the shaded state where the light from the preceding vehicle is shaded, as shown in Fig. 3(c), a shaded light distribution pattern is implemented in which the main high beam is irradiated from the high beam irradiator 5, but the sub-high beam is not irradiated from the high beam irradiator 6. At this time, the output light amount of the main high beam is equal to the output light amount of the main high beam in the normal light distribution pattern, regardless of the temperature state of the main high beam. In the shaded state, the number of lit LEDs is reduced, so the high temperature state of the main high beam is suppressed.

[0044] Conventionally, when the high beam becomes hot due to heat generation of the LED itself, the high beam is turned off and the low beam is turned up or down. However, in this case, the driver of the vehicle feels that it is dark because the high beam is turned off.

[0045] To address such a problem, in this embodiment, when the temperature of the main high beam reaches or exceeds a specified temperature while the main high beam is on and the sub-high beam is on or off, the light output of the main high beam decreases and the light output of the sub-high beam compensates for the decrease in the light output of the main high beam. In other words, even if the light output of the main high beam decreases, the light distribution load of the headlamp 3 is distributed so that the decrease in the light output of the main high beam is compensated for by the sub-high beam. Therefore, the brightness in front of the vehicle 2 by the high beam is ensured. In addition, because the light output of the main high beam decreases, the high temperature state of the high beam is alleviated.

[0046] In addition, in this embodiment, by making the output light amount of the main high beam equal to the output light amount of the main high beam in the normal light distribution pattern when the preceding vehicle is blocking the light, the discomfort felt by the driver of the vehicle 2 can be reduced.

[0047] The present invention is not limited to the above embodiment. For example, in the above embodiment, when blocking the light from the preceding vehicle, the main high beam is irradiated so as to block the light from the preceding vehicle, and the sub-high beam is not irradiated, but the present invention is not particularly limited to such a form. For example, when blocking the light from the preceding vehicle in a state where not only the main high beam but also the sub-high beam is irradiated, the main high beam and the sub-high beam may be irradiated so as to block the light from the preceding vehicle.

[0048] In the above embodiment, the output light amount of the main high beam when the preceding vehicle is shaded is equal to the output light amount of the main high beam in the normal light distribution pattern, but this is not limited to this. If the high temperature state of the main high beam continues when the preceding vehicle is shaded, the output light amount of the main high beam may be reduced below that of the normal light distribution pattern. [Explanation of symbols]

[0049] 1...headlamp device, 3...headlamp, 5...high beam irradiation section (first high beam irradiation section), 6...high beam irradiation section (second high beam irradiation section), 9...temperature sensor (temperature detection section), 11...control ECU (control section).

Claims

[Claim 1] a headlamp having a first high beam irradiating portion that irradiates a first high beam and a second high beam irradiating portion that irradiates a second high beam; a temperature detector that detects a temperature of the first high beam; a control unit that controls the first high beam irradiator and the second high beam irradiator so that, when the temperature of the first high beam detected by the temperature detection unit is equal to or higher than a predetermined specified temperature, the output light amount of the first high beam decreases and the output light amount of the second high beam compensates for the decrease in the output light amount of the first high beam.

Images