Vehicle lamp control device and vehicle lamp

Abstract

This vehicle lamp control device comprises: switches electrically connected in parallel to a plurality of light sources which are electrically connected in series; and a switch control unit for switching on / off the switches so as to supply the respective light sources with pulse currents. The switch control unit supplies the plurality of light sources with pulse currents having different duty periods. When performing specific control in which, during a period for supplying a first light source with a first pulse current, a second light source different from the first light source is supplied with a second pulse current having a duty period shorter than that of the first pulse current, the switch control unit controls the switches so that the first light source is supplied, in addition to the first pulse current, with a complementary pulse current for complementing the first pulse current.

Description

Vehicle lighting device control device and vehicle lighting device

[0001] The present invention relates to a control device for a vehicle lamp and a vehicle lamp.

[0002] A configuration is known in which a single drive circuit controls the turning on and off of a plurality of light sources (see, for example, Patent Document 1).

[0003] Patent No. 6151523

[0004] The vehicle lamp described in Patent Document 1 has a configuration in which multiple light sources are electrically connected in series, and switches are electrically connected in parallel for each light source, and the light sources are turned on and off by switching the switches on and off. However, when one light source is on and a switch is switched on to turn on a second light source, a period occurs in which no current flows through either light source or the current value decreases from the time the switch is switched on until the light source is boosted to a predetermined voltage. During this period, both light sources are turned off. For example, when pulse width modulation control is performed, if this off period occurs in each cycle, the light sources will be dimmed accordingly.

[0005] The present invention has been made in view of the above, and has an object to provide a control device for a vehicle lamp and a vehicle lamp that are capable of suppressing dimming in a light source.

[0006] A control device for a vehicle lamp according to the present invention includes a switch electrically connected in parallel to each of a plurality of light sources electrically connected in series, and a switch control unit that switches the switch on and off so that a pulse current is supplied to each of the light sources, and when performing specific control to supply pulse currents with different duty periods to the plurality of light sources, and to supply a second pulse current with a shorter duty period than the first pulse current to a second light source different from the first light source within a period in which a first pulse current is supplied to a first light source, the switch control unit controls the switch to supply a complementary pulse current that complements the first pulse current to the first light source in addition to the first pulse current.

[0007] A vehicle lamp according to the present invention includes a plurality of light sources and the vehicle lamp control device described above that controls the plurality of light sources.

[0008] According to the present invention, it is possible to provide a control device for a vehicle lamp and a vehicle lamp that are capable of suppressing dimming in a light source.

[0009] FIG. 1 is a diagram schematically illustrating an example of a vehicle lamp according to this embodiment. FIG. 2 is a timing chart illustrating an example of the timing of switch control and turning on and off a light source. FIG. 3 is a timing chart illustrating an example of the timing of switch control and turning on and off a light source. FIG. 4 is a timing chart illustrating an example of switch control and turning on and off a light source. FIG. 5 is a timing chart illustrating an example of switch control and turning on and off a light source. FIG. 6 is a diagram schematically illustrating another example of a vehicle lamp according to this embodiment. FIG. 7 is a timing chart illustrating another example of switch control and turning on and off a light source. FIG. 8 is a timing chart illustrating another example of switch control and turning on and off a light source.

[0010] Hereinafter, embodiments of a vehicle lighting control device and a vehicle lighting device according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same.

[0011] Fig. 1 is a diagram schematically illustrating an example of a vehicle lamp 100 according to this embodiment. As shown in Fig. 1, the vehicle lamp 100 according to this embodiment includes a light source unit 10 and a control device (vehicle lamp control device) 20.

[0012] The light source unit 10 has a plurality of light sources 11. In this embodiment, for example, two light sources 11 are included. The plurality of light sources 11 may be light-emitting elements such as LEDs. The plurality of light sources 11 are electrically connected in series. Hereinafter, when distinguishing between the plurality of light sources 11, they will be referred to as a first light source 11a and a second light source 11b. The plurality of light sources 11 are light sources of functional lamps that constitute the vehicle lamp 100. In this embodiment, the first light source 11a may be a light source of a turn lamp, for example. In this case, the second light source 11b may be a light source of a functional lamp other than a turn lamp, such as a clearance lamp or a daytime running lamp. Hereinafter, the second light source 11b is assumed to be a light source of a clearance lamp.

[0013] The control device 20 controls the plurality of light sources 11 of the light source unit 10. The control device 20 is a control circuit. The control device 20 has a plurality of switches 21, a switch control unit 22, and a power control unit 23.

[0014] The switches 21 are electrically connected in parallel to each of the light sources 11. One switch 21 is provided for each light source 11. Hereinafter, when distinguishing between the switches 21, they will be referred to as a first switch 21a and a second switch 21b. In this embodiment, the first switch 21a is electrically connected in parallel to the first light source 11a, and the second switch 21b is electrically connected in parallel to the second light source 11b.

[0015] The switch 21 can be switched on and off. When the switch 21 is in an off state, no current flows through the switch 21, but current flows through the light source 11 connected in parallel to the switch 21. On the other hand, when the switch 21 is in an on state, the light source 11 connected in parallel to the switch 21 is short-circuited, so that no current flows through the light source 11, but current flows through the switch 21. Therefore, by turning the switch 21 off, the light source 11 connected in parallel to the switch 21 is turned on. On the other hand, by turning the switch 21 on, the light source 11 connected in parallel to the switch 21 is turned off.

[0016] The switch control unit 22 controls the switch 21 based on a control signal from, for example, a lighting instruction unit 30 provided on the vehicle side. The control signal is a control signal for turning on or off the light source 11. When the driver performs a predetermined operation to turn on a function lamp, the lighting instruction unit 30 generates and outputs a control signal to turn on the function lamp corresponding to the predetermined operation.

[0017] The switch control unit 22 switches the switches 21 on and off so that a pulse current is supplied to each of the light sources 11. The switch control unit 22 performs pulse width modulation control to supply pulse currents with different duty periods to the plurality of light sources 11.

[0018] In this pulse width modulation control, the switch control unit 22 may perform control (specific control) to supply a second pulse current having a shorter duty period than the first pulse current to a second light source 11b different from the first light source 11a during a period in which a first pulse current is supplied to a first light source 11a that is one of the plurality of light sources 11. When performing this specific control, the switch control unit 22 controls the first switch 21a to supply, to the first light source 11a, the first pulse current as well as a complementary pulse current that complements the first pulse current.

[0019] The switch control unit 22 has a memory unit 24 and a processing unit 25. The memory unit 24 stores programs and data related to the control of the switch control unit 22. For example, the memory unit 24 stores reference data and complementary data. The reference data includes first drive data D1 and second drive data D2. The first drive data D1 is data for driving the first switch 21a to supply a first pulse current to the first light source 11a. The second drive data D2 is drive data for driving the second switch 21b to supply a second pulse current to the second light source 11b. The complementary data DS is drive data for driving the first switch 21a to supply a complementary pulse current to the first light source 11a. The processing unit 25 outputs a control signal for switching the switch 21 based on the data stored in the memory unit 24.

[0020] The power control unit 23 controls the power supplied to the light source unit 10, i.e., the plurality of light sources 11. The power control unit 23 converts, for example, the voltage of the power supply unit 40 on the vehicle side into a predetermined voltage corresponding to the light source unit 10, and applies it to the light source unit 10. As the power control unit 23, for example, a DC-DC converter or the like is used.

[0021] Next, the operation of the vehicle lamp 100 configured as described above will be described. Figures 2 and 3 are timing charts showing an example of the control of the switch 21 and the timing of turning on and off the light source 11. In Figures 2 and 3, the vertical axis represents the magnitude of the current and the horizontal axis represents time. When the driver of the vehicle performs a predetermined operation to turn on the function lamp, the lighting instruction unit 30 generates and outputs a control signal to turn on the function lamp in accordance with the driver's operation.

[0022] For example, when a predetermined operation to turn on the turn lamp is performed by the driver, the lighting instruction unit 30 generates and outputs a command signal to instruct the first light source 11 a, which is the light source of the turn lamp, to turn on. When the switch control unit 22 receives the command signal from the lighting instruction unit 30, it performs control to turn on the first light source 11 a in accordance with the command signal.

[0023] In this case, in the switch control unit 22, the processing unit 25 extracts the first drive data D1 stored in the memory unit 24, generates a first control signal S1 for controlling the first switch 21a based on the first drive data D1, and outputs the generated first control signal S1. FIG. 2 is a timing chart showing the on / off timing of the first switch 21a and the current supplied to the first light source 11a. As shown in FIG. 2, the first control signal S1 is a pulse signal in which periods in which the first switch 21a is off and periods in which the first switch 21a is on are alternately repeated. During the off period of the first switch 21a, the first light source 11a is turned on. During the on period of the first switch 21a, the first light source 11a is turned off. Therefore, a first pulse current C1 based on the first control signal S1 flows through the first light source 11a. As shown in FIG. 2, when the first light source 11a is turned on from an off state, the value of the current flowing through the first light source 11a gradually increases during the period from when the first switch 21a is switched from an on state to an off state until the voltage of the first light source 11a is increased to a predetermined voltage.

[0024] Furthermore, for example, when a predetermined operation to turn on the clearance lamps is performed by the driver, the lighting instruction unit 30 generates and outputs a command signal to instruct the second light source 11b, which is the light source of the clearance lamps, to be turned on. When the switch control unit 22 receives the command signal from the lighting instruction unit 30, it performs control to turn on the second light source 11b in accordance with the command signal.

[0025] In this case, in the switch control unit 22, the processing unit 25 extracts the second drive data D2 stored in the memory unit 24, generates a second control signal S2 for controlling the second switch 21b based on the second drive data D2, and outputs the generated second control signal S2. FIG. 3 is a timing chart showing the on / off timing of the second switch 21b and the current supplied to the second light source 11b. As shown in FIG. 3, the second control signal S2 is a pulse signal in which periods in which the second switch 21b is off and periods in which the second switch 21b is on are alternately repeated. During periods in which the second switch 21b is off, the second light source 11b is turned on. During periods in which the second switch 21b is on, the second light source 11b is turned off. Note that the on period of the second light source 11b is shorter than that of the first light source 11a. In other words, the second light source 11b is supplied with a pulse current having a shorter on-duty period than that of the first light source 11a. Therefore, the second pulse current C2 based on the second control signal S2 flows through the second light source 11b. Note that, when the second light source 11b is turned on from an off state, the value of the current flowing through the second light source 11b gradually increases during the period from when the second switch 21b is switched from an on state to an off state until the voltage of the second light source 11b is increased to a predetermined voltage, as shown in FIG.

[0026] Furthermore, for example, when the driver performs a predetermined operation to simultaneously turn on the turn signal lamps and the clearance lamps, the lighting instruction unit 30 generates and outputs a command signal to turn on the first light source 11 a and the second light source 11 b. When the switch control unit 22 receives the command signal from the lighting instruction unit 30, it performs control to turn on the first light source 11 a and the second light source 11 b in accordance with the command signal.

[0027] In this case, in the switch control unit 22, the processing unit 25 extracts the first drive data D1 and the second drive data D2 stored in the memory unit 24. The processing unit 25 generates a first control signal S1 for controlling the first switch 21a based on the first drive data D1, and generates a second control signal S2 for controlling the second switch 21b based on the second drive data D2.

[0028] When controlling the first switch 21a and the second switch 21b in parallel, the processing unit 25 determines whether the control corresponds to specific control. That is, the processing unit 25 determines whether there is a timing to supply the second pulse current C2 to the second light source 11b within the period in which the first pulse current C1 is supplied to the first light source 11a. If the processing unit 25 determines that the control does not correspond to specific control, it outputs a first control signal S1 to the first switch 21a and a second control signal S2 to the second switch 21b.

[0029] When the processing unit 25 determines that the specific control is applicable, it controls the first switch 21a in response to the first control signal S1 so as to supply the first light source 11a with a complementary pulse current CS that complements the first pulse current C1 in addition to the first pulse current C1. Figures 4 and 5 are timing charts showing the on / off timings of the first switch 21a and the second switch 21b and the currents supplied to the first light source 11a and the second light source 11b. Note that Figure 4 shows the state before the complementary pulse current is used. In Figures 4 and 5, the vertical axis represents the magnitude of the current, and the horizontal axis represents time.

[0030] In the case where two or more types of pulse currents with different duty periods are supplied to a plurality of light sources 11 electrically connected in series as in the present embodiment, if, for example, supply of a second pulse current C2 with a short duty period to a second light source 11b is started during a period in which a first pulse current C1 with a long duty period is supplied to a first light source 11a, the current value flowing through the first light source 11a and the second light source 11b decreases during a voltage rise period from the start of supply of the second pulse current C2 until a predetermined voltage is reached, as shown in Fig. 4. When such a dimming period occurs, the brightness of the first light source 11a and the second light source 11b when turned on becomes lower than the desired brightness.

[0031] For this reason, as shown in FIG. 5 , the switch control unit 22 generates a first control signal S1 to supply a complementary pulse current CS to the first light source 11a to complement the first pulse current C1. The processing unit 25 generates the first control signal S1 based on complementary data DS stored in the storage unit 24. The complementary data DS is data for driving the first switch 21a to supply a pulse current having the same current value as the first pulse current C1 as the complementary pulse current CS for only a period corresponding to the voltage boost period of the second light source 11b. The complementary data DS is set in advance based on the voltage boost period of the second light source 11b and the current value of the first pulse current C1. In the example shown in FIG. 5 , the switch control unit 22 controls the supply of the complementary pulse current CS so that it is supplied immediately after the supply of the first pulse current C1 begins.

[0032] In this embodiment, when the first pulse current C1 is supplied to the first light source 11a and the second pulse current C2 is supplied to the second light source 11b, if the supply of the second pulse current C2 is terminated for the multiple light sources 11 electrically connected in series, an excessive current will flow through the first light source 11a at the time the supply of the second pulse current C2 is terminated, damaging the first light source 11a. Therefore, the switch control unit 22 generates the first control signal S1 and the second control signal S2 so that the supply of the second pulse current C2 to the second light source 11b is not terminated during the period in which the first pulse current C1 is supplied to the first light source 11a. In this case, as shown in FIG. 5 , the switch control unit 22 generates the first control signal S1 and the second control signal S2 so that the supply of the first pulse current C1 and the second pulse current C2 is terminated at the same timing. When the supply of the first pulse current C1 and the supply of the second pulse current C2 end at the same timing, the switch control unit 22 can generate the first control signal S1 in performing the specific control so that the complementary pulse current CS is supplied immediately after the supply of the first pulse current C1 starts. In other words, the switch control unit 22 generates the first control signal S1 so that the complementary pulse current CS is supplied immediately before the supply of the first pulse current C1 starts.

[0033] As described above, the control device 20 according to this embodiment includes the switches 21 electrically connected in parallel to each of the plurality of light sources 11 electrically connected in series, and the switch control unit 22 that switches the switches 21 on and off so that a pulse current is supplied to each of the light sources 11. When performing specific control to supply pulse currents with different duty periods to the plurality of light sources 11, such that a second pulse current C2 having a shorter duty period than the first pulse current C1 is supplied to a second light source 11b different from the first light source 11a within a period in which a first pulse current C1 is supplied to the first light source 11a, the switch control unit 22 controls the switch 21 to supply, to the first light source 11a, the first pulse current C1 as well as a complementary pulse current CS that complements the first pulse current C1.

[0034] According to this configuration, when the supply of the second pulse current C2 to the second light source 11b is started during the period in which the first pulse current C1 is supplied to the first light source 11a, the period in which the first light source 11a is turned off until the voltage of the second light source 11b is increased can be complemented by turning on the first light source 11a with the complementary pulse current CS, thereby suppressing a decrease in brightness of the first light source 11a during pulse width modulation control.

[0035] In the control device 20 according to this embodiment, the switch control unit 22 controls the switch 21 so as not to terminate the supply of the second pulse current C2 to the second light source 11b within the period in which the first pulse current C1 is supplied to the first light source 11a.

[0036] According to this configuration, it is possible to prevent an excessive current from flowing through the first light source 11a when the supply of the second pulse current C2 ends, thereby preventing damage to the first light source 11a.

[0037] In the control device 20 according to this embodiment, the switch control section 22 controls the switch 21 so that the supply of the first pulse current C1 and the supply of the second pulse current C2 end at the same timing.

[0038] According to this configuration, by terminating the supply of the first pulse current C1 and the second pulse current C2 at the same timing, it is possible to easily set the timing of supplying the complementary pulse current CS.

[0039] In the control device 20 according to this embodiment, when performing specific control, the switch control section 22 controls the supply of the complementary pulse current CS consecutively with the timing at which the supply of the first pulse current C1 starts.

[0040] According to this configuration, by controlling the supply of the complementary pulse current CS to be continuous with the timing at which the supply of the first pulse current C1 starts, it is possible to appropriately set the timing at which the complementary pulse current CS is supplied while preventing damage to the first light source 11a.

[0041] In the control device 20 according to this embodiment, the complementary pulse current CS has the same current value as the first pulse current C1 and is a pulse current for a period corresponding to the voltage increase period from when a voltage is applied to the second light source 11b until the current starts to flow.

[0042] According to this configuration, by turning on the first light source 11a with the complementary pulse current CS, it is possible to appropriately complement the off period of the first light source 11a.

[0043] In the control device 20 according to this embodiment, the first light source 11 a is a light source for a turn signal lamp, and is connected to the position of the plurality of light sources 11 that provides the highest voltage to the power supply unit 40 .

[0044] According to this configuration, the first light source 11a can be kept lit unless a ground fault occurs at the high-potential terminal of the first light source 11a among the plurality of light sources 11. This makes it possible to prevent the turn signal lamp from failing to function.

[0045] The vehicle lamp 100 according to this embodiment includes a plurality of light sources 11 and the above-described control device 20 that controls the plurality of light sources 11 .

[0046] According to this configuration, since the control device 20 is provided that can suppress a decrease in brightness of the first light source 11a among the plurality of light sources 11, it is possible to provide a vehicle lamp 100 that can be turned on with sufficient brightness.

[0047] 6 is a diagram showing another example of a control device for a vehicle lamp. As shown in Fig. 6, a vehicle lamp 200 includes a light source unit 110 and a control device (vehicle lamp control device) 120.

[0048] In the example shown in FIG. 6 , the light source unit 110 has three light sources 11 as the multiple light sources. The configuration of each light source 11 is the same as in the above embodiment. When distinguishing between the multiple light sources 11, they are referred to as a first light source 11a, a second light source 11b, and a third light source 11c. The first light source 11a may be, for example, a light source for a turn signal lamp. In this case, the second light source 11b and the third light source 11c may be light sources for functional lamps other than the turn signal lamp, such as clearance lamps. Hereinafter, the second light source 11b is assumed to be the light source for the first clearance lamp. Furthermore, the third light source 11c is assumed to be the light source for the second clearance lamp. The first clearance lamp and the second clearance lamp are different clearance lamps mounted on a single vehicle lamp 100. Furthermore, the turn signal lamp, the first clearance lamp, and the second clearance lamp are assumed to be arranged so that they can be turned on simultaneously.

[0049] The control device 120 controls the plurality of light sources 11 of the light source unit 110. The control device 120 is a control circuit. The control device 120 has a plurality of switches 21, a switch control unit 22, and a power control unit 23.

[0050] The switches 21 are electrically connected in parallel to the light sources 11. When distinguishing between the switches 21, they are referred to as a first switch 21a, a second switch 21b, and a third switch 21c. In this embodiment, the first switch 21a is electrically connected in parallel to the first light source 11a, the second switch 21b is electrically connected in parallel to the second light source 11b, and the third switch 21c is electrically connected in parallel to the third light source 11c.

[0051] Next, the operation of the vehicle lamp 200 configured as described above will be described. For example, when the driver performs a predetermined operation to simultaneously turn on the turn lamps, the first clearance lamps, and the second clearance lamps, the lighting instruction unit 30 generates and outputs a command signal to turn on the first light source 11 a, the second light source 11 b, and the third light source 11 c, respectively. When the switch control unit 22 receives the command signal from the lighting instruction unit 30, it performs control to turn on the first light source 11 a, the second light source 11 b, and the third light source 11 c in accordance with the command signal.

[0052] In the switch control unit 22, the processing unit 25 extracts the first drive data D1, second drive data D2, and third drive data D3 stored in the storage unit 24. The processing unit 25 generates a first control signal S1 for controlling the first switch 21a based on the first drive data D1, generates a second control signal S2 for controlling the second switch 21b based on the second drive data D2, and generates a third control signal S3 for controlling the third switch 21c based on the third drive data D3.

[0053] When the first switch 21 a, the second switch 21 b, and the third switch 21 c are controlled in parallel, the processing unit 25 determines whether the control corresponds to specific control. That is, the processing unit 25 determines that the control corresponds to first specific control if there is a timing to supply the second pulse current C2 to the second light source 11 b or a timing to supply the third pulse current C3 to the third light source 11 c within a period in which the first pulse current C1 is supplied to the first light source 11 a. Furthermore, the processing unit 25 determines that the control corresponds to second specific control if there is a timing to supply the third pulse current C3 to the third light source 11 c within a period in which the second pulse current C2 is supplied to the second light source 11 b.

[0054] If the processing unit 25 determines that the specific control does not apply, it outputs a first control signal S1 to the first switch 21a, a second control signal S2 to the second switch 21b, and a third control signal S3 to the third switch 21c.

[0055] When the processing unit 25 determines that the first specific control is applicable, it controls the first switch 21a to supply, to the first light source 11a, the first pulse current C1 and a complementary pulse current CS that complements the first pulse current C1 in response to the first control signal S1. When the processing unit 25 determines that the second specific control is applicable, it controls the second switch 21b to supply, to the second light source 11b, the second pulse current C2 and a complementary pulse current CS that complements the second pulse current C2 in response to the second control signal S2.

[0056] The following describes the case where the first specific control and the second specific control are performed. Figures 7 and 8 are timing charts showing the on and off timings of the first switch 21a, the second switch 21b, and the third switch 21c, and the currents supplied to the first light source 11a, the second light source 11b, and the third light source 11c. Note that Figure 7 shows the state before complementation by the complementary pulse current. In Figures 7 and 8, the vertical axis represents the magnitude of the current, and the horizontal axis represents time.

[0057] As shown in FIG. 7 , during the voltage boost period from the start of supply of the second pulse current C2 until the predetermined voltage is reached, the current value flowing through the first light source 11a and the second light source 11b decreases, and the first light source 11a and the second light source 11b are turned off or dimmed. Note that during this voltage boost period, no current flows through the third light source 11c, so the third light source 11c is not affected. Also, during the voltage boost period from the start of supply of the third pulse current C3 until the predetermined voltage is reached, the current value flowing through the first light source 11a, the second light source 11b, and the third light source 11c decreases, and the first light source 11a and the second light source 11b are turned off or dimmed. The second light source 11b has a shorter on-period than the first light source 11a. That is, the second light source 11b is supplied with a pulse current having a shorter on-period duty cycle than the first light source 11a. The third light source 11c has a shorter on-period than the second light source 11b. That is, the third light source 11c is supplied with a pulse current having a smaller duty cycle during its lighting period than the first light source 11a and the second light source 11b.

[0058] 8, the switch control unit 22 generates a first control signal S1 to supply a complementary pulse current CS1 for complementing the first pulse current C1 to the first light source 11a. Through this process, the first switch 21a is controlled to supply a pulse current having the same current value as the first pulse current C1 as the complementary pulse current CS1 only for a period corresponding to the boost period of the second light source 11b.

[0059] Furthermore, the switch control unit 22 generates a second control signal S2 to supply a complementary pulse current CS2 for complementing the second pulse current C2 to the second light source 11 b. Through this process, the second switch 21 b is controlled to supply a pulse current having the same current value as the second pulse current C2 as the complementary pulse current CS2 only for a period corresponding to the boost period of the third light source 11 c.

[0060] 8, during the supply period of the first pulse current C1, two extinguishing periods occur due to the start of lighting of the second light source 11b and the third light source 11c. Also, during the supply period of the second pulse current C2, one extinguishing period occurs due to the start of lighting of the third light source 11c.

[0061] Thus, the more times a pulse current with a relatively short duty period is supplied during a period in which a pulse current with a relatively long duty period is supplied, the more current loss occurs and the longer the off period becomes. Therefore, the switch control unit 22 can control the supply period of the complementary pulse current to be longer as the number of times a pulse current with a relatively short duty period is supplied during a period in which a pulse current with a relatively long duty period is supplied. This makes it possible to appropriately supply the complementary pulse current according to the current loss period of the pulse current with a relatively long duty period.

[0062] DESCRIPTION OF SYMBOLS 10, 110... light source unit, 11... light source, 11a... first light source, 11b... second light source, 11c... third light source, 20, 120... control device, 21... switch, 21a... first switch, 21b... second switch, 21c... third switch, 22... switch control unit, 23... power control unit, 24... storage unit, 25... processing unit, 30... lighting instruction unit, 40... power supply unit, 100, 200... vehicular lamp

Claims

1. A control device for a vehicle lamp, comprising: a switch electrically connected in parallel to each of a plurality of light sources electrically connected in series; and a switch control unit configured to switch on and off the switch so that a pulse current is supplied to each of the light sources, wherein the switch control unit performs control to supply pulse currents having different duty periods to the plurality of light sources, and when performing specific control of supplying a second pulse current having a duty period smaller than that of the first pulse current to a second light source different from the first light source during a period in which the first pulse current is supplied to the first light source, the switch is controlled to supply, in addition to the first pulse current, a complementary pulse current that complements the first pulse current to the first light source.

2. The control device for a vehicle lamp according to claim 1, wherein the switch control unit controls the switch so as not to terminate the supply of the second pulse current to the second light source during a period in which the first pulse current is supplied to the first light source.

3. The control device for a vehicle lamp according to claim 2, wherein the switch control unit controls the switch so that the timings of the end of the supply of the first pulse current and the second pulse current are the same.

4. The control device for a vehicle lamp according to claim 1, wherein when performing the specific control, the switch control unit controls to supply the complementary pulse current continuously following the timing of the start of the supply of the first pulse current.

5. The control device for a vehicle lamp according to claim 1, wherein the complementary pulse current has the same current value as the first pulse current and is a pulse current for a period corresponding to a voltage boost period from when a voltage is applied to the second light source until a current flows.

6. The control device for a vehicle lamp according to claim 1, wherein the switch control unit controls the switch so that the supply period of the complementary pulse current becomes longer as the number of times of supply of the second pulse current during the supply period of the first pulse current increases for each first pulse current.

7. The control device for a vehicle lamp according to claim 1, wherein the first light source is a light source of a turn lamp and is connected at a position where the voltage becomes the highest with respect to a power supply unit among the plurality of light sources.

8. A vehicle lamp, comprising: a plurality of light sources; and the control device for a vehicle lamp according to any one of claims 1 to 7, configured to control the plurality of light sources.

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