Vehicle lighting fixtures

Abstract

To provide a vehicle lamp which prevents another driver from feeling uneasiness due to a change in brightness when a plurality of passing operations are performed while a current applied to a light source is changed.SOLUTION: A vehicle lamp includes LED light sources 2 and 3 of a headlight 1, a semiconductor light source lighting circuit 6 connected to the LED light sources 2 and 3, and a lamp controller 7 connected to the semiconductor light source lighting circuit 6. The semiconductor light source lighting circuit 6 has a circuit configuration having a function that reduces an application current I to the LED light sources 2 and 3 in accordance with a temperature T when the temperature T inside a lamp becomes equal to or higher than a first set temperature T1 due to the surrounding environment when the headlamp 1 is lit. The lamp controller 7 includes a light source current control unit 72 that outputs to the semiconductor light source lighting circuit 6 a fixed command for fixing the application current I to the LED light sources 2 and 3 at the time of the passing operation until a first set time ST1 elapses after the passing operation when the passing operation is performed while the application current I to the LED light sources 2 and 3 is changing.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle lamp. [Background technology]

[0002] A semiconductor light source lighting circuit that achieves a steeper temperature derating slope has been known. The conventional circuit includes a DC / DC converter that supplies current to the LED, a current detection resistor that generates a current detection voltage, a control unit that controls the DC / DC converter to reduce the difference between the current detection voltage and the comparison voltage, and a comparison voltage generation unit that generates the comparison voltage. The comparison voltage generation unit includes a temperature detection unit that generates a thermistor divided voltage according to the LED temperature, a voltage-to-current conversion unit that converts the thermistor divided voltage into a thermistor divided current using a coefficient determined by the resistance value of a sixth resistor, and a current application unit that applies an adjustment current of the same magnitude as the thermistor divided current to the first resistor (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-160277 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional semiconductor light source lighting circuits are configured with a function (hereinafter referred to as a "temperature derating function") that reduces the current applied to the semiconductor light source in accordance with the temperature when the temperature inside the lamp exceeds a predetermined temperature due to the surrounding environment when the headlight is turned on. However, while the current applied to the semiconductor light source is changing, the brightness of the semiconductor light source also changes in accordance with the change in applied current. Therefore, if the driver turns on the headlights multiple times while the current applied to the semiconductor light source is changing, the brightness of the semiconductor light source also changes each time. When the driver signals the other party by turning on the headlights, the change in brightness can cause the other party to feel uncomfortable.

[0005] The present disclosure has been made with a focus on the above-mentioned problem, and aims to provide a vehicle lamp that can prevent discomfort felt by other people due to changes in brightness when the flashing operation is performed multiple times while the current applied to the light source is changing. [Means for solving the problem]

[0006] To achieve the above object, the present disclosure provides a vehicle lamp comprising a headlamp light source, a light source lighting circuit connected to the light source, and a lamp controller connected to the light source lighting circuit. In this vehicle lamp, the light source lighting circuit has a circuit configuration that has a function of reducing the current applied to the light source in accordance with the temperature when the temperature inside the lamp reaches or exceeds a predetermined temperature due to the surrounding environment when the headlights are turned on. The lamp controller has a light source current control unit that, when a passing operation is performed while the current applied to the light source is changing, outputs a fixation command to the light source lighting circuit to fix the current applied to the light source at the time of the passing operation until a set time has elapsed since the passing operation. When the set time has elapsed during which the light source current control unit has output a command to fix the applied current, it releases the fixation of the applied current and outputs a command to restore the applied current-temperature relationship characteristics from the current-temperature operating point at the time the set time has elapsed using the upper limit gradient angle set by the light source lighting circuit. [Effects of the Invention]

[0007] Therefore, when the flashing operation is performed multiple times while the current applied to the light source is being changed, it is possible to prevent the other party from feeling uncomfortable due to the change in brightness. After the fixed control of the applied current is completed, the applied current-temperature relationship characteristics can be restored with good response to temperature increases or decreases. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing a semiconductor light source control unit of a headlamp, which is a vehicle lamp according to a first embodiment. [Figure 2] 5 is a flowchart showing the flow of an applied current control process in a light source current control unit of the lighting fixture controller of the first embodiment. [Figure 3] FIG. 10 is an applied current-temperature relationship characteristic diagram showing the relationship between the applied current and temperature when two passing operations are performed while the applied current is decreasing due to a rise in temperature inside the lamp in a semiconductor light source lighting circuit of a comparative example. [Figure 4]10 is an applied current-temperature relationship characteristic diagram showing the relationship between the applied current and temperature when two passing operations are performed while the applied current is decreasing due to a rise in temperature inside the lamp in the semiconductor light source lighting circuit of Example 1. FIG. [Figure 5] 10 is a flowchart showing the flow of an applied current control process in a light source current control unit of a lighting fixture controller according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vehicle lamp according to an embodiment of the present disclosure will be described based on a first embodiment and a second embodiment shown in the drawings. [Example]

[0010] The vehicle lighting fixture in Example 1 is applied to a semiconductor light source control unit of a headlamp having a high beam LED light source and a low beam LED light source, among front combination lamps installed on the left and right sides of the front of an automobile.

[0011] First, the configuration of a semiconductor light source control unit A for a headlamp will be described with reference to FIG.

[0012] As shown in Fig. 1, the semiconductor light source control unit A includes a headlamp 1, a high beam LED light source 2, a low beam LED light source 3, an on-board power supply 4, a light switch 5, a semiconductor light source lighting circuit 6, a lamp controller 7, and a passing operation sensor 8. Here, LED is an abbreviation for "Light Emitting Diode." The high beam LED light source 2 and the low beam LED light source 3 are examples of light sources, and will be referred to as "LED light sources 2, 3" hereinafter.

[0013] The headlamp 1 is configured by combining LED light sources 2, 3 with optical components such as a lens body and a reflector (not shown) and arranging them inside a lamp housing 10. In addition to the LED light sources 2, 3, a semiconductor light source lighting circuit 6 is also arranged inside the lamp housing 10 in a position close to the LED light sources 2, 3. The semiconductor light source lighting circuit 6 may be arranged outside the lamp housing 10 instead of inside.

[0014] The semiconductor light source lighting circuit 6 is a drive circuit that controls the on / off and applied current of the LED light sources 2 and 3, which are semiconductor light sources, and is called an LED driver. A first output terminal 6a of the semiconductor light source lighting circuit 6 is connected to the high beam LED light source 2 by a first conductive harness 21. A second output terminal 6b of the semiconductor light source lighting circuit 6 is connected to the low beam LED light source 3 by a second conductive harness 31. A power supply terminal 6c of the semiconductor light source lighting circuit 6 is connected to the on-board power supply 4 by a power supply harness 41 via the light switch 5.

[0015] The circuit board of the semiconductor light source lighting circuit 6 is provided with a temperature sensor 61 together with a DC / DC converter, etc. The semiconductor light source lighting circuit 6 has a circuit configuration with a temperature derating function that reduces the current I applied to the LED light sources 2, 3 in accordance with the level of temperature T when the temperature T inside the lamp exceeds a predetermined temperature due to the ambient environment when the headlamp 1 is turned on (see FIG. 3). Here, the "temperature derating function" refers to a function that operates the semiconductor light source lighting circuit 6 and the LED light sources 2, 3 with an applied current I that is equal to or less than a predetermined rated current value in accordance with the level of temperature T inside the lamp, in order to protect the semiconductor light source lighting circuit 6 and the LED light sources 2, 3 from thermal degradation.

[0016] For example, when temperature T rises, the applied current I is reduced in response to the rise in temperature T, as shown by arrow B in Figure 3, thereby achieving a temperature derating function. While the temperature is below the first set temperature T1, the applied current I to the LED light sources 2, 3 is fixed at the first rated current I1 (basic rated current). When temperature T exceeds the first set temperature T1, the first rated current I1 applied to the LED light sources 2, 3 is reduced in response to the rise in temperature. When temperature T exceeds the second set temperature T2, the applied current I to the LED light sources 2, 3 is fixed at the second rated current I2 (high temperature range rated current).

[0017] Conversely, when the temperature T inside the lamp drops from a fixed state at the second rated current I2 (high temperature range rated current), the applied current I is increased in response to the drop in temperature T, as shown by arrow C in Figure 3, thereby restoring the lamp to the first rated current I1 (basic rated current). When the temperature T drops below the second set temperature T2, the second rated current I2 applied to the LED light sources 2 and 3 is increased in response to the drop in temperature. When the temperature T reaches the first set temperature T1, the applied current I to the LED light sources 2 and 3 is fixed at the first rated current I1. Note that the first set temperature T1 < the second set temperature T2, and the first rated current I1 > the second rated current I2.

[0018] An NTC thermistor or the like is used as the temperature sensor 61, and detects the temperature inside the lamp around the LED light sources 2, 3. The temperature sensor 61 is particularly disposed in the interior space of the lamp housing 10 in which the LED light sources 2, 3 are mounted, at a position near the LED light sources 2, 3 so that the resistance value changes in good response to an increase or decrease in the temperature around the LED light sources 2, 3.

[0019] When a passing operation by the driver is detected by a passing operation sensor 8, the lamp controller 7 performs passing control, which switches the lighting state of the headlamp 1, on the semiconductor light source lighting circuit 6, and also controls the current applied to the LED light sources 2 and 3. A first output terminal 7a of the lamp controller 7 is connected to the semiconductor light source lighting circuit 6 by a first output signal line 74. A second output terminal 7b of the lamp controller 7 is connected to the semiconductor light source lighting circuit 6 by a second output signal line 75. A first input terminal 7c of the lamp controller 7 is connected to the passing operation sensor 8 by a first input signal line 76. A second input terminal 7d of the lamp controller 7 is connected to the temperature sensor 61 by a second input signal line 77. The lamp controller 7 has a passing control circuit 71, a light source current control unit 72, and a timer 73.

[0020] Here, "passing" refers to a method of communicating with drivers of oncoming vehicles, etc. by temporarily turning on the headlights 1 that are off to high beam while driving the vehicle, or by temporarily switching the headlights 1 that are on low beam to high beam while the vehicle is being driven.

[0021] The passing operation sensor 8 is a sensor that detects a passing operation by the driver, who pulls the operating lever 9 of the light switch 5 toward himself (arrow D in FIG. 1) and then releases the operating lever 9 to return it to its original lever position. Here, the operating lever 9 is provided at an upper position of the steering column near the steering wheel, protruding in the vehicle width direction, etc.

[0022] The light switch 5 is built into the operating lever 9, and the switch mode position is changed by rotating the operating lever 9 in stages in the direction of arrow E in FIG. 1. The switch mode positions include, for example, the off position, auto light position, side light position, and head light position. In the off position, all exterior lamps are turned off. In the auto light position, sensors detect and control the automatic turning on of lamps such as headlights 1, side light, and tail light. In the tail light position, the side light and tail light are turned on. In the head light position, the headlights 1, side light, and tail light are turned on. The light switch 5 is turned on when switched from the off position to the auto light position or the head light position.

[0023] When the passing operation sensor 8 inputs a passing operation signal from the driver, the passing control circuit 71 performs passing control, which switches the lighting state of the headlights 1 on the semiconductor light source lighting circuit 6. When it detects that the operation lever 9 has been pulled toward the driver, the passing control circuit 71 outputs a high beam lighting command to the semiconductor light source lighting circuit 6 while the operation lever 9 is being pulled toward the driver. After that, when it detects that the driver has released the operation lever 9, the passing control circuit 71 outputs a command to turn off the high beam-lit headlights 1 or a command to switch to low beam-lit headlights to the semiconductor light source lighting circuit 6. Note that when the light switch 5 is turned off to turn off the headlights 1, the semiconductor light source lighting circuit 6 is disconnected from the on-board power supply 4, but when a passing operation is performed, the light switch 5 automatically switches from off to on.

[0024] The light source current control unit 72 receives an operation sensor signal from the passing operation sensor 8 and a temperature sensor signal from the temperature sensor 61 and controls the current I applied to the LED light sources 2, 3. If the passing operation is performed while the current applied to the LED light sources 2, 3 is changing, the light source current control unit 72 outputs a fixation command to the semiconductor light source lighting circuit 6 to fix the current applied to the LED light sources 2, 3 at the time of the passing operation until a first set time ST1 has elapsed since the passing operation. The timer 73 counts the time from the passing operation until the first set time ST1 has elapsed. Here, the light source current control unit 72 performs the same current control for the two LED light sources 2, 3. However, if the current control is performed separately for the two LED light sources 2, 3, the light source current control unit 72 may control the current applied only to the high beam LED light source 2 that is turned on when the light sources are passing.

[0025] Here, the light source current control unit 72 determines that the applied current I to the LED light sources 2, 3 is changing when the temperature T acquired by the temperature sensor signal from the temperature sensor 61 is within the temperature range from the first set temperature T1 to the second set temperature T2.

[0026] The light source current control unit 72 determines the first set time ST1 after a passing operation based on the time required when multiple passing operations are performed. In other words, the time required when multiple passing operations are performed is verified by experiment or the like, and the first set time ST1 is determined by adding the required time based on the verification results to a time for variation due to individual differences.

[0027] When the first set time ST1 during which the light source current control unit 72 has output a command to fix the applied current I has elapsed, the light source current control unit 72 releases the fixation of the applied current I. Then, it outputs a command to restore the applied current-temperature relationship characteristics from the current-temperature operating point at the time when the first set time ST1 has elapsed to the upper limit range gradient angle θmax in the semiconductor light source lighting circuit 6. Here, the "upper limit range gradient angle θmax" refers to the upper limit range gradient angle achievable in the semiconductor light source lighting circuit 6, out of the gradient angles at which the applied current I decreases with respect to an increase in temperature T, or the gradient angles at which the applied current I increases with respect to a decrease in temperature T.

[0028] Next, the operation of the first embodiment will be explained by dividing it into "the operation of controlling the applied current in the light source current control unit," "the comparison operation when a passing operation is performed while the applied current is decreasing," and "the characteristic operation of the applied current control."

[0029] The flow of the applied current control process in the light source current control unit 72 of the lighting fixture controller 7 will be described with reference to the flowchart in Fig. 2. The flowchart in Fig. 2 starts when the light switch 5 is turned off and then on, and is repeated until the light switch 5 is turned off.

[0030] When the current applied to the LED light sources 2 and 3 has not changed, the flow of S11 → RETURN is repeated, and the light source current control unit 72 does not perform fixed control of the applied current. That is, when the temperature T is less than the first set temperature T1 or the temperature T is greater than the second set temperature T2, it is determined that the current applied to the LED light sources 2 and 3 has not changed.

[0031] Although the current applied to the LED light sources 2 and 3 is changing, when there is no passing operation, the flow of S11 → S12 → return is repeated, and the applied current is not fixed by the light source current control unit 72. In other words, when the temperature T is within the range of not less than the first set temperature T1 and not more than the second set temperature T2, it is determined that the current applied to the LED light sources 2 and 3 is changing.

[0032] If the current applied to the LED light sources 2 and 3 has changed and the driver has performed a passing operation, the process proceeds in the order S11 → S12 → S13 → S14 → S15. In step S13, if the driver has performed a passing operation, a timer value corresponding to a first set time ST1 is set. In step S14, if the driver has performed a passing operation, the current applied to the LED light sources 2 and 3 is fixed to the current applied when the driver performed a passing operation. In S15, it is determined whether the duration since the driver performed a passing operation has exceeded the first set time ST1.

[0033] In step S15, while it is determined that the elapsed time since the passing operation has not exceeded the first set time ST1, the process flow advancing from S15 to S16 is repeated. In step S16, the previous timer value is decreased according to the processing cycle.

[0034] On the other hand, in step S15, when it is determined that the elapsed time since the passing operation has exceeded the first set time ST1, the process advances from step S15 to step S17. In step S17, the fixing of the applied current I is released, and a command to return to the applied current-temperature relationship characteristic (Figure 3) before the application current fixing from the operating point (Ic, Te) at the time when the first set time ST1 has elapsed is output to the semiconductor light source lighting circuit 6, and then the process returns.

[0035] Referring to FIGS. 3 and 4, the comparative operation when a passing operation is performed during the decrease of the applied current will be described.

[0036] In the comparative example, in a semiconductor light source lighting circuit having a temperature dilating function, it is assumed that the higher the temperature T in the lamp unit, the lower the applied current I even when a passing operation intervenes. In the case of the comparative example, when a plurality of passing operations are performed during the change of the applied current I to the semiconductor light source, the brightness of the semiconductor light source also changes as the applied current I changes.

[0037] Therefore, as shown in FIG. 3, in the semiconductor light source lighting circuit, when the first passing operation is performed at a temperature Ta (>T1) during the decrease of the applied current I due to the increase in the temperature T in the lamp unit, the applied current I becomes Ia. Thereafter, when the second passing operation is performed at a temperature Tb (>Ta) during the decrease of the applied current I, the applied current I becomes Ib (<Ia). When the temperature T rises during the continuation of the high beam lighting, the applied current I slightly decreases from Ia and Ib as the temperature rises.

[0038] In this way, in the temperature range (T1≦Temperature T≦T2) where the applied current I changes, for example, if the headlights are turned on twice, the brightness of the semiconductor light source changes so that the second time it is dimmer than the first time. As a result, in the comparative example, when a signal is conveyed to the other party by turning on the headlights multiple times, the change in brightness makes the other party feel uncomfortable.

[0039] In contrast, in Example 1, if a passing operation is performed while the current applied to the LED light sources 2 and 3 is changing, the current Ic applied to the LED light sources 2 and 3 at the time of the first passing operation is fixed until the first set time ST1 has elapsed since the first passing operation. In other words, in Example 1, even if multiple passing operations are performed, the brightness of the LED light sources 2 and 3 does not change because the applied current Ic is fixed as long as the passing operation is performed before the first set time ST1 has elapsed.

[0040] 4, when the first flashing operation is performed at temperature Tc while the applied current I is decreasing due to a rise in temperature T inside the lamp in the semiconductor light source lighting circuit 6, the applied current I is fixed to the applied current Ic at the start of the detection of the flashing operation. Even if a second flashing operation is performed at temperature Td (>Tc) while the applied current Ic is still maintained, the applied current I remains fixed at Ic. Additionally, even if the temperature T rises while the high beams are still on, the applied current I remains fixed at Ic.

[0041] In this way, in the temperature range (T1≦temperature T≦T2) where the applied current I changes, for example, if the driver flashes the headlights twice, the brightness of the LED light sources 2, 3 will be maintained at the same brightness for the first and second times. As a result, when the driver flashes the headlights 1 multiple times to signal to the other party, the driver can prevent the other party from feeling uncomfortable due to the change in brightness. Here, the discomfort caused by the change in brightness includes the discomfort caused by the brightness of the headlights 1 becoming darker due to an increase in temperature T, and the discomfort caused by the brightness of the headlights 1 becoming brighter due to a decrease in temperature T.

[0042] Next, the characteristic action of the applied current control will be described.

[0043] In the semiconductor light source lighting circuit 6 of the first embodiment, a temperature sensor 61 that detects a temperature T inside the lamp is provided in the circuit, and the circuit is configured to have a relationship characteristic in which the applied current I changes according to the temperature T when the temperature T is in a temperature range from a first set temperature T1 to a second set temperature T2. A sensor signal from the temperature sensor 61 is input to a light source current control unit 72, and when the temperature T acquired by the sensor signal is in the temperature range from the first set temperature T1 to the second set temperature T2, it is determined that the applied current I to the LED light sources 2, 3 is changing.

[0044] That is, the determination that the applied current I to the LED light sources 2, 3 is changing can be made by directly detecting the change in the applied current I to the LED light sources 2, 3. However, in this case, a monitoring time required to confirm that the applied current I is changing is set, and the determination that the applied current I to the LED light sources 2, 3 is changing is made after the monitoring time has elapsed, resulting in a delay in the timing of the determination. In response to this, we focused on the fact that the temperature sensor 61 is provided within the semiconductor light source lighting circuit 6, and that the semiconductor light source lighting circuit 6 has a circuit configuration with a relationship characteristic in which the applied current I changes depending on the temperature T within a predetermined temperature range. That is, when the temperature T acquired by the temperature sensor 61 is within the temperature range from the first set temperature T1 to the second set temperature T2, it is determined that the applied current I to the LED light sources 2, 3 is changing. Therefore, by determining that the applied current I to the LED light sources 2, 3 is changing based on the temperature T inside the lighting fixture acquired from the temperature sensor 61, a delay in the timing of determining that the applied current I is changing is prevented.

[0045] In the light source current control unit 72 of the first embodiment, when the passing operation sensor 8 is used and a lever operation of pulling the operation lever 9 of the light switch 5 toward oneself is detected, it is determined that a passing operation has been performed.

[0046] That is, when the driver operates the flashers, it is necessary to responsively detect the flashing operation, including the start of the flashing operation. To address this, attention is focused on the fact that the flashing operation is performed by pulling the operating lever 9 of the light switch 5 toward oneself. Therefore, by using the flashing operation sensor 8 that detects the lever operation, it is possible to responsively detect the intervention of the flashing operation, including the start of the flashing operation.

[0047] In the light source current control unit 72 of the first embodiment, when the first set time ST1 during which a command to fix the applied current I has elapsed, the fixation of the applied current I is released. Then, a command is output to restore the applied current-temperature relationship characteristics (FIG. 4) from the current-temperature operating point (Ic, Te) at the time when the first set time ST1 has elapsed, using the upper limit range gradient angle θmax in the semiconductor light source lighting circuit 6.

[0048] In other words, fixed control of the applied current I causes the current-temperature operating point to deviate from the current-temperature operating point on the applied current-temperature relationship characteristic that provides the temperature derating function. Therefore, when the fixed control of the applied current I is released, the current-temperature operating point must be restored to the original applied current-temperature relationship characteristic. In this case, as shown by the dashed-dotted line in Figure 4, a comparative example is shown in which the current-temperature operating point (Ic, Te) at the time when the first set time ST1 has elapsed is restored to the applied current-temperature relationship characteristic by the characteristic gradient angle θn in the semiconductor light source lighting circuit 6. In this comparative example, when the applied current-temperature relationship characteristic is restored, the current-temperature operating point becomes (I2, T3).

[0049] In contrast, in the case of the first embodiment, as shown by the solid line in FIG. 4, starting from the current-temperature operating point (Ic, Te) when the first set time ST1 has elapsed, the semiconductor light source lighting circuit 6 returns to the applied current-temperature relationship characteristic according to the upper limit region gradient angle θmax. Therefore, when returning to the applied current-temperature relationship characteristic, the current-temperature operating point becomes (I2, T2) (T2 < T3). Accordingly, after the fixed control of the applied current I ends, it is possible to return to the applied current-temperature relationship characteristic in good response to an increase or decrease in the temperature T. In particular, by returning to the applied current-temperature relationship characteristic in good response when the temperature T is rising, the function of protecting the semiconductor light source lighting circuit 6 and the LED light sources 2 and 3 from thermal degradation can be maintained.

[0050] In the light source current control unit 72 of the first embodiment, the set time after a passing operation is defined as the first set time ST1 determined based on the required time when multiple passing operations are performed.

[0051] That is, in accordance with the fact that problems occur during multiple passing operations, the set time after a passing operation is determined based on the required time when multiple passing operations are performed. Therefore, when sending a signal to the other party by multiple passing operations with a simple control process in which the duration of fixing the applied current I is set to one determined first set time ST1, it is possible to prevent the sense of discomfort given to the other party due to a change in brightness.

[0052] As described above, in the vehicle lamp of the first embodiment, the following effects can be obtained.

[0053] (1) The vehicle lamp includes a light source (LED light sources 2, 3) for a headlamp 1, a light source lighting circuit (semiconductor light source lighting circuit 6) connected to the light source (LED light sources 2, 3), and a lamp controller 7 connected to the light source lighting circuit (semiconductor light source lighting circuit 6). In this vehicle lamp, the light source lighting circuit (semiconductor light source lighting circuit 6) has a circuit configuration that, when the temperature T inside the lamp rises to or exceeds a predetermined temperature (first set temperature T1) due to the surrounding environment when the headlamp 1 is turned on, reduces the current I applied to the light source (LED light sources 2, 3) in accordance with the level of the temperature T. The lamp controller 7 has a light source current control unit 72 that, when a flashing operation is performed while the current I applied to the light source (LED light sources 2, 3) is changing, outputs a fixation command to the light source lighting circuit (semiconductor light source lighting circuit 6) to fix the current I applied to the light source (LED light sources 2, 3) at the time of the flashing operation until a set time (first set time ST1) has elapsed since the flashing operation. Therefore, when the flashing operation is performed multiple times while the applied current I to the light source (LED light sources 2, 3) is changing, it is possible to prevent the other party from feeling uncomfortable due to the change in brightness.

[0054] (2) The light source lighting circuit (semiconductor light source lighting circuit 6) is provided with a temperature sensor 61 for detecting a temperature T inside the lamp, and is configured to have a relationship characteristic in which the applied current I changes according to the temperature T when the temperature T is within a temperature range from a first set temperature T1 to a second set temperature T2. The light source current control unit 72 receives a sensor signal from the temperature sensor 61, and determines that the applied current I to the light source (LED light sources 2, 3) is changing when the temperature T acquired by the sensor signal is within a temperature range from the first set temperature T1 to the second set temperature T2. Therefore, by determining that the applied current I to the light source (LED light sources 2, 3) is changing based on the temperature T inside the lamp acquired from the temperature sensor 61, a delay in determining that the applied current I is changing can be prevented.

[0055] (3) Using the passing operation sensor 8, the light source current control unit 72 determines that a passing operation has occurred when it detects a lever operation of pulling the operating lever 9 of the light switch 5 toward itself. Therefore, by using the passing operation sensor 8 that detects lever operation, it is possible to responsively detect the intervention of a passing operation, including the start of a passing operation.

[0056] (4) When the set time (first set time ST1) during which the command to fix the applied current I has elapsed, the light source current control unit 72 releases the fixation of the applied current I. Then, it outputs a command to restore the applied current-temperature relationship characteristics from the current-temperature operating point (Ic, Te) at the time the set time (first set time ST1) has elapsed, using the upper limit range gradient angle θmax in the light source lighting circuit (semiconductor light source lighting circuit 6). Therefore, after the fixation control of the applied current I is completed, the applied current-temperature relationship characteristics can be restored with good response to an increase or decrease in the temperature T.

[0057] (5) The light source current control unit 72 sets the set time from the flashing operation to a first set time ST1 that is determined based on the time required for multiple flashing operations. Therefore, by using a simple control process that sets the duration for which the applied current I is fixed to the single, determined first set time ST1, it is possible to prevent the other party from feeling uncomfortable due to changes in brightness when signaling multiple flashing operations to the other party. [Example]

[0058] The second embodiment is an example in which the method of determining the set time after the passing operation is different from that of the first embodiment.

[0059] The overall configuration of the second embodiment is the same as that of the semiconductor light source control unit A of the headlamp 1 of the first embodiment shown in Fig. 1. Below, the configuration of the light source current control unit 72 that differs from that of the first embodiment will be described.

[0060] The light source current control unit 72 sets the set time from the start of a passing operation as a second set time ST2, which is determined based on the required time from the first passing operation to the second passing operation when consecutive passing operations are performed. When the current I applied to the LED light sources 2 and 3 is fixed due to a passing operation, if a next passing operation occurs before the second set time ST2 has elapsed, the remaining time is reset to the second set time ST2 from the next passing operation. In other words, when two consecutive passing operations are performed, the required time for the first passing operation is verified by experiment or the like, and the time interval between the end of one passing operation and the start of the next passing operation is also verified by experiment or the like. The second set time ST2 is then determined by adding the required time, the time interval, and the variation time based on the verification results (ST1 > ST2). Note that other configurations are similar to those of the first embodiment, and therefore will not be described here.

[0061] Next, the flow of the applied current control process in the light source current control unit 72 of the lamp controller 7 of the second embodiment will be described with reference to the flowchart in Fig. 5. The flowchart in Fig. 5 starts when the light switch 5 is turned off and then on, and is repeated until the light switch 5 is turned off.

[0062] When the applied current to the LED light sources 2 and 3 has not changed, the flow of S21 → Return is repeated. When the applied current to the LED light sources 2 and 3 has changed but there is no passing operation, the flow of S21 → S22 → Return is repeated. In either case, the light source current control unit 72 does not perform fixed control of the applied current, as in the first embodiment.

[0063] If the current applied to the LED light sources 2 and 3 has changed and there has been a passing operation, the process proceeds in the order S21 → S22 → S23 → S24 → S25. In step S23, if there has been a passing operation, a timer value corresponding to the second set time ST2 is set. In step S24, if there has been a passing operation, the current applied to the LED light sources 2 and 3 is fixed to the current applied at the start of the passing operation detection. In S25, it is determined whether the duration since the passing operation has occurred has exceeded the second set time ST2.

[0064] In step S25, if it is determined that the duration since the passing operation has not elapsed the second set time ST2, and there is no next passing operation, the flow of proceeding from S25 to S26 to S28 is repeated. In step S28, the previous timer value is decremented according to the processing cycle.

[0065] Thereafter, in step S25, if it is determined that the duration since the start of the passing operation detection has not elapsed the second set time ST2 and the next passing operation is performed, the flow from S25 to S26 to S27 is repeated. In step S27, the timer value that has been decremented is reset to the timer value corresponding to the second set time ST2.

[0066] On the other hand, if it is determined in step S25 that the duration since the start of the passing operation detection has exceeded the second set time ST2, the process proceeds from step S25 to step S29. In step S29, the fixation of the applied current I is released, and a command is output to the semiconductor light source lighting circuit 6 to restore the applied current-temperature relationship characteristic (FIG. 3) from the operating point (Ic, Te) at the time when the second set time ST2 has elapsed to the applied current-temperature relationship characteristic before the applied current was fixed, and the process proceeds to RETURN.

[0067] In the light source current control unit 72 of the second embodiment, when there is a passing operation, the set time after the passing operation is defined as a second set time ST2 determined based on the required time from the first passing operation to the second passing operation when the passing operations are performed continuously. When the applied current I to the LED light sources 2 and 3 is fixed due to a passing operation, if there is a next passing operation before the second set time ST2 elapses, the remaining time is reset to the second set time ST2 after the next passing operation.

[0068] That is, the second set time ST2 (<ST1) is determined based on the required time from the first passing operation to the second passing operation when the passing operations are performed continuously. Therefore, when a passing operation is performed only once in step S22, when the second set time ST2 elapses after the passing operation, the fixing of the applied current I is released. Thus, when a passing operation is performed only once, since the fixing of the applied current I is released when the second set time ST2 (<the first set time ST1) elapses, it is possible to prevent the fixing of the applied current I from continuing longer than necessary.

[0069] If there is a next passing operation before the second set time ST2 elapses, the remaining time at that time is reset to the second set time ST2 from the start of detection of the next passing operation. Therefore, when passing operations are performed continuously multiple times, if a next passing operation is performed before the second set time ST2 is reached, the fixing of the applied current I is maintained regardless of the number of passing operations performed due to the reset of the set time. Thus, when passing operations are performed continuously multiple times, it is possible to prevent the fixing of the applied current I from being released during the passing operations regardless of the number of times.

[0070] As described above, in the vehicle lamp of the second embodiment, in addition to the effects of (1) to (4) of the first embodiment, the following effects can be obtained.

[0071] (6) When consecutive passing operations are performed, the light source current control unit 72 sets the set time from the passing operation to a second set time ST2, which is determined based on the time required from the first passing operation to the second passing operation. When the applied current I to the light source (LED light sources 2, 3) is fixed upon detection of a passing operation, if the next passing operation occurs before the second set time ST2 has elapsed, the remaining time is reset to the second set time ST2 from the next passing operation. This prevents the applied current I from being fixed for longer than necessary when only one passing operation is performed. In addition, when multiple passing operations are performed consecutively, it prevents the applied current I from being released from its fixed state midway through a passing operation, regardless of the number of times.

[0072] The vehicle lamp of the present disclosure has been described above based on Examples 1 and 2, but the specific configuration is not limited to these Examples, and design changes and additions are permitted as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0073] In the first and second embodiments, examples have been shown in which semiconductor light sources, consisting of a high-beam LED light source 2 and a low-beam LED light source 3, are used as the light source. However, the light source is not limited to an LED light source, and other semiconductor light sources that handle high current, such as a semiconductor laser light source, may also be used. Furthermore, the light source is not limited to a semiconductor light source, and may be a halogen light source or a discharge light source equipped with a light source lighting circuit having a temperature derating function.

[0074] In the first and second embodiments, the semiconductor light source lighting circuit 6 has been shown to have a circuit configuration having a relationship characteristic in which the applied current I changes in accordance with the temperature T when the temperature T from the temperature sensor 61 provided in the circuit is within a temperature range from a first set temperature T1 to a second set temperature T2. However, the semiconductor light source lighting circuit may also have a circuit configuration having a relationship characteristic in which the applied current changes in accordance with the temperature when the temperature from the temperature sensor provided in the circuit is equal to or higher than a predetermined temperature. In this case, the light source current control unit determines that the applied current to the semiconductor light source is changing when the temperature from the temperature sensor is equal to or higher than the predetermined temperature.

[0075] In the first and second embodiments, a preferred example has been shown in which the light source current control unit 72, when the fixation of the applied current I is released, returns from the current-temperature operating point at the time when a set time has elapsed to the applied current-temperature relationship characteristic at the upper limit range gradient angle θmax in the semiconductor light source lighting circuit 6. However, the light source current control unit may also be an example in which, when the fixation of the applied current is released, returns from the current-temperature operating point at the time when a set time has elapsed to the applied current-temperature relationship characteristic at an appropriately set gradient angle. [Explanation of symbols]

[0076] A Semiconductor light source control unit 1 Headlight 2 High beam LED light source (light source) 3 Low beam LED light source (light source) 4 Onboard power supply 5. Light Switch 6 Semiconductor light source lighting circuit (light source lighting circuit) 61 Temperature Sensor 7 Lighting fixture controller 71 Passing control unit 72 Light source current control section 8 Passing operation sensor 9 Operating lever T temperature I applied current T1 1st set temperature T2 2nd set temperature ST1 First setting time ST2 Second setting time

Claims

1. A vehicle lamp including a headlight light source, a light source lighting circuit connected to the light source, and a lamp controller connected to the light source lighting circuit, the light source lighting circuit is configured to have a function of reducing a current applied to the light source in accordance with the level of a temperature inside the lamp when the temperature inside the lamp exceeds a predetermined temperature due to a surrounding environment when the headlamp is turned on, the lamp controller has a light source current control unit that outputs a fixation command to the light source lighting circuit when a passing operation is performed while a current applied to the light source is changing, to fix the current applied to the light source at the time of the passing operation until a set time has elapsed since the passing operation, the light source current control unit releases the fixation of the applied current when the set time during which the fixation command for the applied current has elapsed; A command is output to restore the applied current-temperature relationship characteristic from the current-temperature operating point at the time when the set time has elapsed to the upper limit range gradient angle by the light source lighting circuit. A vehicle lamp characterized by the above.

2. A vehicle lamp including a headlight light source, a light source lighting circuit connected to the light source, and a lamp controller connected to the light source lighting circuit, the light source lighting circuit is configured to have a function of reducing a current applied to the light source in accordance with the level of a temperature inside the lamp when the temperature inside the lamp exceeds a predetermined temperature due to a surrounding environment when the headlamp is turned on, the lamp controller has a light source current control unit that outputs a fixation command to the light source lighting circuit when a passing operation is performed while a current applied to the light source is changing, to fix the current applied to the light source at the time of the passing operation until a set time has elapsed since the passing operation, The light source current control unit sets the set time from the occurrence of the passing operation as a first set time determined based on a required time when the passing operation is performed a plurality of times. A vehicle lamp characterized by the above.

3. The vehicular lamp according to claim 1 or 2, the light source lighting circuit is provided with a temperature sensor in its circuit for detecting the temperature inside the lamp, and when the temperature is within a temperature range from a first set temperature to a second set temperature, the applied current has a relational characteristic that changes in accordance with the level of the temperature; The light source current control unit inputs a sensor signal from the temperature sensor, and when the temperature acquired by the sensor signal is within a temperature range from the first set temperature to the second set temperature, determines that the current applied to the light source is changing. A vehicle lamp characterized by the above.

4. The vehicular lamp according to any one of claims 1 to 3, The light source current control unit detects, using a passing operation sensor, that a passing operation has been performed when a lever operation of pulling the operation lever of the light switch toward oneself is detected. A vehicle lamp characterized by the above.

5. The vehicle lamp according to claim 1, The light source current control unit sets the set time from the occurrence of the passing operation as a first set time determined based on a required time when the passing operation is performed a plurality of times. A vehicle lamp characterized by the above.

6. The vehicle lamp according to claim 1, the light source current control unit sets the set time from the occurrence of the passing operation as a second set time determined based on a required time from the occurrence of a first passing operation to the occurrence of a second passing operation when passing operations are performed consecutively, When the current applied to the light source is fixed due to the passing operation, if a next passing operation occurs before the second set time has elapsed, the remaining time is reset to the second set time from the time of the next passing operation. A vehicle lamp characterized by the above.

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