VEHICLE LIGHT

Abstract

Vehicle lamp (100A), which includes: a first light source (110); a second light source (120); a first input terminal (IN1) that receives a first power-on command signal (S1), which instructs the first light source (110) to be switched on and off; a second input terminal (IN2) that receives a pulsed second switch-on command signal (S2) which instructs the switching on / off of the second light source (120); and a switching circuit (200A) that controls the first light source (110) and the second light source (120) based on the first switch-on command signal (S1) and the second switch-on command signal (S2), the switching circuit (200A) includes: a drive circuit (210A) that is activated based on the first switch-on command signal (S1) and the second switch-on command signal (S2) and outputs a constant drive current from an output terminal; and a distribution circuit (220A) that forms a current path such that the driver current to the second light source (120) flows in an input state of the second switch-on command signal (S2), and that forms a current path such that the driver current to the first light source (110) flows in a non-input state of the second switch-on command signal (S2), wherein one end of the first light source (110) and one end of the second light source (120) are connected to an output of the drive circuit (210A), the drive circuit (210A) is enabled when at least the first switch-on command signal (S1) and / or the second switch-on command signal (S2) is at a switch-on level, and The distribution circuit (220A) includes: a first switch (SW1) which is connected to the other end of the first light source (110); a second switch (SW2) which is connected to the other end of the second light source (120), and a control circuit (222) which, in the non-input state of the second power-on command signal (S2), switches on the first switch (SW1) and off the second switch (SW2), and in the input state of the second power-on command signal (S2), switches off the first switch (SW1) and switches the second switch (SW2) according to the second power-on command signal (SW2).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2019-010584, filed with the Japan Patent Office on January 24, 2019, claiming priority therefrom, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL AREA

[0002] This communication concerns a vehicle lamp used in a motor vehicle or the like. BACKGROUND

[0003] A car contains a variety of lamps that differ in their function. Examples of such lamps include high or low beams, a clearance lamp (position lamp), a daytime running lamp (DRL), and a turn signal. Because the clearance lamp and turn signal are located close together, these lamps are often housed in the same housing.

[0004] Fig. 1 is a block diagram of a lamp system 1R including a vehicle lamp 10R of the corresponding technology. In Fig. 1 shows a block in conjunction with a clearance lamp and a turn signal. The vehicle lamp 10R receives a turn signal signal S1 and a turn signal signal S2 and, in accordance with the signals, switches on a light source 12C for the clearance lamp and a light source 12T for the turn signal. The light source 12C comprises a plurality of white light-emitting elements (e.g., LEDs) arranged in series (or parallel). The light source 12T comprises a plurality of yellow light-emitting elements arranged in series (or parallel).

[0005] The vehicle lamp 10R includes a switch-on circuit 14C for the clearance lamp and a switch-on circuit 14T for the turn signal lamp. When the switch-on command signal S1 is in an on state, the switch-on circuit 14C supplies a control current I for switching on. LED1 to the light source 12C.

[0006] The switch-on command signal S2 is a pulse signal with a period of approximately 0.7 seconds and a duty cycle of 50%. While the switch-on command signal S2 is at a high level, the switch-on circuit 14T supplies a control current I LED2 to the light source 12T and causes the light source 12T to blink. See Japanese Patent Open Publication JP 2006 - 221 886 A.

[0007] DE 10 2016 205 583 A1 discloses a control circuit for a plurality of light source units configured to perform different functions, for example, a turn indicator and a daytime running light. DE 10 2011 018 573 A1 discloses a control device for a lighting system of a motor vehicle, which comprises at least one LED assigned to a turn indicator and at least one LED assigned to another light type (e.g., daytime running light or position light), and a common optical arrangement for the light types. SUMMARY

[0008] In the related art vehicle lamp 10R, the clearance lamp and the turn signal lamp are formed as independent circuits, and there is a problem that the cost is high and the size is large.

[0009] The present disclosure has been made in view of such problems, and one aspect thereof is to provide a vehicle lamp in which a clearance lamp and a turn signal lamp are integrated.

[0010] One aspect of the present disclosure relates to a vehicle lamp according to claims 1 and 3. The vehicle lamp comprises: a first light source; a second light source; a first input terminal receiving a first turn-on command signal instructing turning on / off of the first light source; a second input terminal receiving a pulsed second turn-on command signal instructing turning on / off of the second light source; and a turn-on circuit controlling the first light source and the second light source based on the first turn-on command signal and the second turn-on command signal.The turn-on circuit includes a drive circuit that is activated based on the first turn-on command signal and the second turn-on command signal and outputs a constant drive current from an output terminal, and a distribution circuit that forms a current path so that the drive current flows to the second light source in an input state of the second turn-on command signal and forms a current path so that the drive current flows to the first light source in a non-input state of the second turn-on command signal.

[0011] Another aspect of the present disclosure also relates to a vehicle lamp according to claims 5 and 6. The vehicle lamp comprises: a first light source; a second light source; a first input terminal receiving a first turn-on command signal instructing turning the first light source on / off; a second input terminal receiving a pulsed second turn-on command signal instructing turning the second light source on / off; and a turn-on circuit controlling the first light source and the second light source based on the first turn-on command signal and the second turn-on command signal.The turn-on circuit (i) turns on the second light source immediately and turns off the first light source immediately when the second turn-on command signal transitions to the on level while the first turn-on command signal is in the on level, and (ii) turns off the second light source immediately and turns on the first light source after a predetermined time when the second turn-on command signal transitions to an off level while the first turn-on command signal is in the on level.

[0012] Any combination of the components described above and those obtained by substituting components or terms of the present disclosure for one another among the methods, devices, and systems are also effective as aspects of the present disclosure.

[0013] According to one aspect of this communication, a vehicle lamp having a first and a second light source can be reduced in cost or size.

[0014] The foregoing summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, other aspects, embodiments, and features will become apparent from the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram of a lamp system with a vehicle lamp of the corresponding type. Fig. 2 is a block diagram of a vehicle lamp according to an example. Fig. 3 is a view for explaining an example operation of the vehicle lamp. Fig. 4 is a circuit diagram of a vehicle lamp according to an embodiment 1. Fig. 5 is an operation waveform diagram of the vehicle lamp in Fig. 4. Fig. 6 is a circuit diagram showing a more specific example configuration of the vehicle lamp in Fig. 4 shows. Fig. 7 is a circuit diagram of a vehicle lamp according to an embodiment 2. Fig. 8 is a view for explaining the operation of the vehicle lamp in Fig. 7. Fig. 9 is a circuit diagram showing a more specific example configuration of the vehicle lamp in Fig. 7 shows. Fig. 10A to 10D are views of an LED socket, which is an example of a vehicle lamp. DETAILED DESCRIPTION

[0015] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. The illustrative embodiments described in the detailed description, drawings, and claims are not to be considered limiting. Other embodiments may be utilized and other changes may be made without departing from the spirit or scope of the subject matter presented herein. (Summary of the embodiment)

[0016] In an embodiment disclosed in the present specification, the vehicle lamp comprises: a first light source; a second light source; a first input terminal receiving a first turn-on command signal instructing turning on / off of the first light source; a second input terminal receiving a pulsed second turn-on command signal instructing turning on / off of the second light source; and a turn-on circuit controlling the first light source and the second light source based on the first turn-on command signal and the second turn-on command signal.The turn-on circuit includes a drive circuit that is activated based on the first turn-on command signal and the second turn-on command signal and outputs a constant drive current from an output terminal, and a distribution circuit that forms a current path so that the driver flows to the second light source in an input state of the second turn-on command signal and forms a current path so that the drive current flows to the first light source in a non-input state of the second turn-on command signal.

[0017] Depending on the vehicle lamp, the drive circuit of the first and second light sources can be shared, thus reducing the cost or size of the vehicle lamp. When the second light source is flashing, the first light source can be turned off.

[0018] One end of the first light source and one end of the second light source are connected to the output of the drive circuit. The drive circuit is enabled when at least one of the first turn-on command signals and the second turn-on command signal is at the on level. The distribution circuit includes a first switch connected to the other end of the first light source and a second switch connected to the other end of the second light source, as well as a control circuit that turns the first switch on and turns the second switch off when the second turn-on command signal is not input, and turns the first switch off and switches the second switch according to the second turn-on command signal when the second turn-on command signal is input.

[0019] The control circuit may include a pulse detection circuit that generates a pulse detection signal that is accepted when the second power-on command signal is input and negated when the second power-on command signal is not input. The first switch may be controlled in response to the pulse detection signal, and the second switch may be controlled in response to the pulse detection signal and the second power-on command signal.

[0020] In another embodiment of the vehicle lamp, the first light source and the second light source are connected in series. The drive circuit is activated (i) when the first turn-on command signal is at the turn-on level and the second turn-on command signal is not input, and (ii) when the second turn-on command signal is at the turn-on level. The distribution circuit includes a third switch connected in parallel with the first light source and a fourth switch connected in parallel with the second light source, as well as a control circuit that turns off the third switch and turns on the fourth switch when the second turn-on command signal is not input, and turns on the third switch and turns off the fourth switch when the second turn-on command signal is input.

[0021] The control circuit may include a pulse detection circuit that generates a pulse detection signal that is accepted when the second power-on command signal is input, while being negated when the second power-on command signal is not input. The third switch and the fourth switch may be turned on exclusively in response to the pulse detection signal.

[0022] Another aspect of the present disclosure is also a vehicle lamp. The vehicle lamp includes: a first light source; a second light source; a first input terminal receiving a first turn-on command signal instructing the first light source to turn on / off; a second input terminal receiving a pulsed second turn-on command signal instructing the second light source to turn on / off; and a turn-on circuit controlling the first light source and the second light source based on the first turn-on command signal and the second turn-on command signal.The turn-on circuit (i) turns on the second light source immediately and turns off the first light source immediately when the second turn-on command signal transitions to the on level while the first turn-on command signal is in the on level, and (ii) turns off the second light source immediately and turns on the first light source after a predetermined time when the second turn-on command signal transitions to an off level while the first turn-on command signal is in the on level. [Embodiment]

[0023] Preferred exemplary embodiments of the present disclosure are described below with reference to the drawings. Identical or corresponding components, parts, and processes are denoted by the same symbols in each of the drawings, and overlapping descriptions thereof are omitted accordingly. Furthermore, the embodiments are not intended to limit the present disclosure, but are merely exemplary. Any features described in the embodiments or combinations thereof may not be essential to the present disclosure.

[0024] In this specification, "a state in which a unit A is connected to a unit B" includes not only the case in which the unit A and the unit B are physically connected directly, but also the case in which the unit A and the unit B are indirectly connected via other units that do not significantly affect this electrically connected state or impair the functions and effects exerted by this connection.

[0025] Similarly, a ‘state in which a unit C is provided between unit A and unit B’ includes not only the case in which unit A and unit C or unit B and unit C are directly connected, but also the case in which unit A and unit C or unit B and unit C are indirectly connected via other units which do not significantly affect that electrically connected state or impair the functions and effects exerted by that coupling.

[0026] Furthermore, in this specification, symbols associated with electrical signals such as voltage and current signals or circuit elements such as resistors and capacitors are considered to represent the respective voltage and current values ​​or resistance and capacitance values. [Example]

[0027] Fig. 2 is a block diagram of a vehicle lamp 100 according to an example. The vehicle lamp 100 includes a first light source 110, a second light source 120, and a lighting circuit 200. A specific aspect of the vehicle lamp 100 is an LED socket in which the first light source 110, the second light source 120, and the lighting circuit 200 are housed in a housing and has a shape that can be attached to and detached from a lamp body (not shown). Since the LED socket is a consumable, its long life and low cost are in high demand.

[0028] The first light source 110 is a first light source that is to be switched on in a non-flashing manner according to a switch-on instruction. In the example, the first light source 110 is a flashlight and comprises one or more white semiconductor light sources connected in series. An LED is particularly suitable for the semiconductor light source, but an LD or an organic EL element can also be used. The second light source 120 is a light source that is to be switched on in a flashing manner according to a switch-on instruction. In the example, the second light source 120 is a flashing lamp and comprises one or more amber semiconductor light sources connected in series.

[0029] A first turn-on command signal S1, which instructs the turning on / off of the first light source 110, is input to a first input terminal IN1. The first turn-on command signal S1 is a binary signal that assumes either an on level (e.g., high) or an off level (e.g., low). The on and off levels of the first turn-on command signal S1 instruct the first light source 110 to be turned on and off.

[0030] A second turn-on command signal S2, which instructs the turning on / off of the second light source 120, is input to a second input terminal IN2. The second turn-on command signal S2 is a pulse signal with a predetermined period and a predetermined duty cycle in an active state (input state or enable state), and alternately repeats the on and off levels. When the pulsed second turn-on command signal S2 is in the active state, the second light source 120 flashes according to the second turn-on command signal S2. When the second turn-on command signal S2 is an inactive state (non-input state or disabled state) in which the off level is maintained, the second light source 120 is turned off.

[0031] The first switch-on command signal S1 and the second switch-on command signal S2 can also serve as a power source for the vehicle lamp 100, wherein the respective switch-on levels of the first switch-on command signal S1 and the second switch-on command signal S2 have a battery voltage V BAT can be.

[0032] The switching circuit 200 controls the first light source 110 and the second light source 120 based on the first switching command signal S1 and the second switching command signal S2. The switching circuit 200 includes a drive circuit 210 and a distribution circuit 220.

[0033] The drive circuit 210 is set to the activated state based on the first turn-on command signal S1 and the second turn-on command signal S2 and outputs a constant drive current I LEDat an output terminal OUT. The drive circuit 210 includes a constant current output driver. The configuration of the drive circuit 210 is not particularly limited and can be a linear regulator with a constant current output, a switching converter with a constant current output (DC / DC converter), or a combination of a switching converter with a constant voltage output and a constant current circuit. In addition, the drive current I LED be a constant current or PWM modulated.

[0034] The distribution circuit 220 receives the drive current I generated by the drive circuit 210 LED and (i) forms a current path such that the drive current I LED in the input state of the second switch-on command signal S2 flows to the second light source 120, and (ii) forms a current path so that the drive current I LEDin the non-input state of the second switch-on command signal S2 to the first light source 110. Hereinafter, the drive current supplied to the first light source 110 is referred to as "I LED1 ” and the drive current supplied to the second light source 120 as “I LED2 " designated.

[0035] The above is the configuration of the vehicle lamp 100. An operation thereof will be described below. The following four states can be assumed by the combinations of the first turn-on command signal S1 and the second turn-on command signal S2. Fig. 3 is a view for explaining an example operation of the vehicle lamp 100.

[0036] (i) A state where the first turn-on command signal S1 is in the off state and the second turn-on command signal S2 is not input.

[0037] In this state φ1, the drive circuit 210 is in a blocked state, and the drive current I LED is not generated. Therefore, the control currents I LED1 and I LED2 neither fed by the first light source 110 nor by the second light source 120, and the first light source 110 and the second light source 120 are switched off.

[0038] (ii) A state in which the first turn-on command signal S1 is in the on level and the second turn-on command signal S2 is not input.

[0039] In this state φ2, the drive circuit 210 is in the activated state and the drive current I LED generated at a target level I REF is stabilized. Since the second switch-on command signal S2 is not input, the control current I LED1 supplied to the first light source 110 and only the first light source 110 is switched on.

[0040] (iii) A state where the first turn-on command signal S1 is in the on level and the second turn-on command signal S2 is input.

[0041] In this state φ3, the drive circuit 210 is in the activated state and the drive current I LED generated at target level I REF is stabilized. Since the second switch-on command signal S2 is in the input state, the intermittent drive current I LED2 supplied to the second light source 120, and the second light source 120 flashes. The first light source 110 is turned off.

[0042] (iv) A state in which the first turn-on command signal S1 is in the off state and the second turn-on command signal S2 is input.

[0043] In this state φ4, the drive circuit 210 is intermittently in the enable state according to the second switch-on command signal S2, and the intermittent drive current I LEDgenerated at target level I REF stabilized. Since the second switch-on command signal S2 is in the input state, the intermittent drive current I LED2 supplied to the second light source 120, and the second light source 120 flashes. The first light source 110 is turned off.

[0044] The above is the operation of the vehicle lamp 100.

[0045] According to the vehicle lamp 100, the first light source 110 and the second light source 120 can be driven by the common drive circuit 210, thus reducing the cost and size of the vehicle lamp 100. Furthermore, when the second light source 120 is blinking, the first light source 110 can be turned off even if the first turn-on command signal S1 is on and the visibility of the blinker is ensured.

[0046] The present disclosure is according to the block diagram or the circuit diagram in Fig. 2 or extends to various apparatus and methods derived from the above description and is thus not limited to any particular configuration. More specific configuration examples or embodiments are described below not to limit the scope of the present disclosure, but to facilitate understanding and clarifying the nature or operation of the present disclosure. [Embodiment 1]

[0047] Fig. 4 is a circuit diagram of a vehicle lamp 100A according to Embodiment 1. In Embodiment 1, the first light source 110 and the second light source 120 are provided in two parallel paths. One end (anode) of the first light source 110 and one end (anode) of the second light source 120 are connected to an output of a driver circuit 210A.

[0048] The drive circuit 210A becomes active (enabled) when at least the first turn-on command signal S1 and / or the second turn-on command signal S2 is at the on level. The drive circuit 210A includes a diode OR circuit 212 and a constant current driver 214. The diode OR circuit 212 includes two diodes whose cathodes are commonly connected, and the first turn-on command signal S1 and the second turn-on command signal S2 are input to their anodes. An output node 213 of the diode OR circuit 212 is connected to the input terminal (power supply terminal or enable terminal) of the constant current driver 214. The constant current driver 214 is in the activated state when at least the first turn-on command signal S1 and / or the second turn-on command signal S2 is at a high level (e.g., battery voltage V BAT ) lies.

[0049] A distribution circuit 220A includes a first switch SW1, a second switch SW2, and a control circuit 222. The first switch SW1 is connected to the other end (cathode) of the first light source 110. The second switch SW2 is connected to the other end (cathode) of the second light source 120. By turning on (conducting) the first switch SW1, the drive current I LED supplied to the first light source 110, by switching on (conducting) the second switch SW2, the drive current I LED the second light source 120.

[0050] The control circuit 222 turns on the first switch SW1 and turns off the second switch SW2 in the non-output state of the second turn-on command signal S2, and turns off the first switch SW1 and turns on the second switch SW2 according to the second turn-on command signal S2 in the input state of the second turn-on command signal S2.

[0051] The control circuit 222 includes a pulse detection circuit 224A and a logic circuit 226. The pulse detection circuit 224A generates a pulse detection signal S3, which is accepted in the input state of the second switch-on command signal S2 and negated in the non-input state.

[0052] The distribution circuit 220A controls the first switch SW1 according to the pulse detection signal S3 and controls the second switch SW2 according to the pulse detection signal S3 and the second turn-on command signal S2. The logic circuit 226 is allowed to turn on the second switch SW2 when the pulse detection signal S3 is present and the second turn-on command signal S2 is at the on level. Alternatively, the logic circuit 226 can control the second switch SW2 based only on the second turn-on command signal S2.

[0053] Fig. 5 is an operation waveform diagram of the vehicle lamp 100A in Fig. 4. In the non-input states φ1 and φ2 of the second power-on command signal S2, the pulse detection signal S3 is negated (here low), and in the input states φ3 and φ4 of the second power-on command signal S2, the pulse detection signal S3 is accepted (here high).

[0054] In state φ2, the first switch SW1 is turned on and the second switch SW2 is turned off and the drive current I generated by the drive circuit 210A LED is fed to the first light source 110 and thus the first light source 110 is switched on.

[0055] In states φ3, φ4, the first switch SW1 is turned off, and the second switch SW2 is switched according to the second turn-on command signal S2. Therefore, the drive current I generated by the drive circuit 210A LED cut and fed to the second light source 120, and thus the second light source 120 flashes.

[0056] Fig. 6 is a circuit diagram showing a more specific example configuration of the vehicle lamp 100A in Fig. 4 shows. The first switch SW1 and the second switch SW2 are N-channel metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0057] The pulse detection circuit 224A includes a capacitor C1, a charging circuit 230 that charges the capacitor C1 when the second turn-on command signal S2 is on, a discharging path 232 that discharges the capacitor C1 with a predetermined time constant, and an inverter 234. The charging circuit 230 includes transistors Tr1 and Tr2 and a plurality of resistors R11 to R14. When the second turn-on command signal S2 is on, the transistors Tr1 and Tr2 are turned on and the capacitor C1 is charged, thus increasing the voltage VC1 of the capacitor C1 to near the voltage of the power source.

[0058] The discharge path 232 includes resistors R15 and R16. While the second turn-on command signal S2 is in the off state, the charge on capacitor C1 is discharged via the discharge path 232, and the capacitor voltage VC1 decreases. When the second turn-on command signal S2 is not input, the capacitor C1 is not charged, and the capacitor voltage VC1 is maintained at 0V.

[0059] When the second power-on command signal S2 is input, since the capacitor C1 is charged in a shorter time than the discharge time constant of the capacitor C1, the capacitor voltage VC1 is maintained at a high level (close to VDD). The inverter 234 binarizes the voltage VC1 of the capacitor C1 into high and low, inverts it, and outputs the voltage VC1. In this configuration, the pulse detection signal S3 ("\" refers to negative logic) is low, and the negation of the pulse detection signal S3 is high.

[0060] The configuration of the pulse detection circuit 224A is not limited to the configuration in Fig. 6. For example, by changing the charging and discharging process, the capacitor C1 can be discharged immediately when the second turn-on command signal S2 is in the on level, and when the second turn-on command signal S2 is in the off level, the capacitor C1 can be charged with a predetermined time constant.

[0061] Logic circuit 226 includes transistors Tr4 and Tr5 and resistors R18 to R22. Logic circuit 226 generates a gate signal S4 of switch SW2 from second turn-on command signal S2 and pulse detection signal S3.

[0062] When the pulse detection signal S3 is low ("accepted") or the second turn-on command signal S2 is at the on level (high), the gate signal S4 becomes high and the second switch SW2 is turned on. When the pulse detection signal S3 is high ("negated") and the second turn-on command signal S2 is at the off level (high), the gate signal S4 becomes low and the second switch SW2 is turned off. [Embodiment 2]

[0063] Fig. 7 is a circuit diagram of a vehicle lamp 100B according to Embodiment 2. In Embodiment 2, the first light source 110 and the second light source 120 are connected in series. A turn-on circuit 200B includes a drive circuit 210B and a distribution circuit 220B.

[0064] The drive circuit 210B is enabled (i) when the first turn-on command signal S1 is at the on level and the second turn-on command signal S2 is not input, and (ii) when the second turn-on command signal S2 is at the on level. The drive circuit 210B includes a diode OR circuit 212B and a constant current driver 214. The diode OR circuit 212B is obtained by adding a switch 215 to the diode OR circuit in Fig. 4. The switch 215 is turned off in the input state of the second power-on command signal S2 and is turned on in the non-input state.

[0065] The distribution circuit 220B includes a third switch SW3, a fourth switch SW4, and a control circuit 222B. The third switch SW3 is connected in parallel with the first light source 110, and the fourth switch SW4 is connected in parallel with the second light source 120. The control circuit 222B turns off the third switch SW3 and turns on the fourth switch SW4 in the non-output state of the second turn-on command signal S2, and turns on the third switch SW3 and turns off the fourth switch SW4 in the input state of the second turn-on command signal S2.

[0066] The control circuit 222B includes a pulse detection circuit 224B and a driver 228. The pulse detection circuit 224B generates the pulse detection signal S3, which is accepted when the second power-on command signal S2 is input and negated when the second power-on command signal S2 is not input. The driver 228 exclusively turns off the third switch SW3 and the fourth switch SW4 according to the pulse detection signal S3. The driver 228 can be omitted depending on the type of switch, etc.

[0067] Fig. Fig. 8 is a view for explaining the operation of the vehicle lamp 100B in Fig. 7.

[0068] In the non-input states φ1 and φ2 of the second switch-on command signal S2, the pulse detection signal S3 is negated (here low), and in the input states φ3 and φ4 of the second switch-on command signal S2, the pulse detection signal S3 is accepted (here high).

[0069] (i) A state where the first turn-on command signal S1 is in the off state and the second turn-on command signal S2 is not input.

[0070] In state φ1, the drive circuit 210B is in a locked state, and the drive current I LED is not generated. Therefore, the control currents I LED1 and I LED2 neither fed by the first light source 110 nor by the second light source 120, and the first light source 110 and the second light source 120 are switched off.

[0071] (ii) A state in which the first turn-on command signal S1 is in the on level and the second turn-on command signal S2 is not input.

[0072] In this state φ2, the drive circuit 210B is in the activated state, and the drive current I LED1 which is at a target level I REFis stabilized, is generated. By turning off the third switch SW3 and turning on the fourth switch SW4, the drive current I LED through the path including the fourth switch SW4 and the first light source 110. Therefore, only the first light source 110 is turned on.

[0073] (iii) A state where the first turn-on command signal S1 is in the on level and the second turn-on command signal S2 is input.

[0074] In this state φ3, the drive circuit 210B is intermittently in the enable state according to the second switch-on command signal S2, and the intermittent drive current I LED generated at which the amplitude is at the target level I REF stabilized. The third switch SW3 is turned on and the fourth switch SW4 is turned off, thus the intermittent drive current I LED2supplied to the second light source 120, and the second light source 120 flashes. The first light source 110 is turned off.

[0075] (iv) A state in which the first turn-on command signal S1 is in the off state and the second turn-on command signal S2 is input.

[0076] In this state φ4, the drive circuit 210B is intermittently in the enable state according to the second switch-on command signal S2, and the intermittent drive current I LED generated at which the amplitude is at the target level I REF stabilized. The third switch SW3 is turned on and the fourth switch SW4 is turned off, thus the intermittent drive current I LED2 supplied to the second light source 120, and the second light source 120 flashes.

[0077] The above is the operation of the vehicle lamp 100B. According to the vehicle lamp 100B, the same effect as the vehicle lamp 100A is achieved.

[0078] Fig. 9 is a circuit diagram showing a more specific example configuration of the vehicle lamp 100B in Fig. 7. The pulse detection circuit 224B causes the pulse detection signal S3 to be present (high level) when the second power-on command signal S2 is input. The pulse detection signal S3 is supplied to a gate (control terminal) of the third switch SW3 and the fourth switch SW4. Since the third switch SW3 is an NMOS transistor and the fourth switch SW4 is a PMOS transistor, when the pulse detection signal S3 (high) is present, the third switch SW3 is turned on and the fourth switch SW4 is turned off, and the drive current I LEDflows to the second light source 120, and thus it is possible to turn on the second light source 120. When the pulse detection signal S3 is negated (high), the third switch SW3 is turned off and the fourth switch SW4 is turned on, and the drive current I LED flows to the first light source 110, and thus it is possible to turn on the first light source 110.

[0079] The switch 215 is a PMOS transistor and is turned on when the pulse detection signal S3 is negated (low) and turned off when the pulse detection signal S3 is activated.

[0080] Pulse detection circuit 224B includes charging circuit 230, capacitor C1, discharge path 232, and a buffer 238. Buffer 238 stores the voltage VC1 of capacitor C1. A Schmitt buffer can be used for buffer 238.

[0081] A high voltage V generated by the diodes D1 and D2 His fed into a power supply terminal of the buffer 238. Therefore, it is possible to reliably turn the fourth switch SW4 and the third switch SW3 on and off.

[0082] The vehicle lamps 100 (100A and 100B) according to the embodiments can be understood as follows.

[0083] The switching circuit 200 (i) the second light source 120 immediately turns on and the first light source 110 immediately turns off when the second turn-on command signal S2 changes to the on level while the first turn-on command signal S1 is in the on level, and (ii) turns off the second light source 120 immediately and turns on the first light source 110 after a predetermined time when the second turn-on command signal S2 goes to the off state while the first turn-on command signal S1 is in the on state. (Application)

[0084] An application of the vehicle lamp 100 is described below. Fig. 10A to 10D are views of an LED socket 700 which is an example of the vehicle lamp 100. Fig. 10A is a perspective view of an exterior of the LED socket 700. Fig. 10B shows the front view of the LED socket 700, Fig. 10C the top view of the LED socket 700 and Fig. 10D the view of the LED socket 700 from below.

[0085] The housing body 702 has a shape that can be attached to and detached from a lamp body (not shown). A plurality of light-emitting elements 504 are mounted in a central portion and covered with a transparent cover 704. Portions of a power-on circuit 600 are mounted on a substrate 710. Some of the plurality of light-emitting elements 504 are LED chips that form the first light source 110, and others are LED chips that form the second light source 120.

[0086] Three fins 721, 722, and 723 are exposed on the underside of the package body 702. The first power-on command signal S1 is supplied to fin 721, and the ground voltage is supplied to fin 722. The second power-on command signal S2 is supplied to fin 723. The fins 721 to 723 penetrate the interior of the package body 702, and one end thereof is connected to a wiring pattern of the substrate 710.

[0087] In the above, the present disclosure has been described based on the embodiments. The exemplary embodiments are merely examples, and one of ordinary skill in the art will understand that various modifications may be made to a combination of corresponding components or corresponding methods, and such modifications also fall within the scope of this disclosure. Such modifications are described below. (Modification 1)

[0088] In embodiment 1 in Fig. 4, the switch 215 can be Fig. 7 to the diode OR circuit 212. In this case, in state φ3, the constant current driver 214 is intermittently in the enabled state according to the second switch-on command signal S2 and the intermittent drive current I LEDIn this case, the second switch SW2 can be permanently switched on when the pulse detection signal S3 is activated. (Modification 2)

[0089] In embodiment 2 in Fig. 7, the switch 215 in the diode-OR circuit 212B can be omitted. In this case, in state φ3, the constant current driver 214 is continuously in the enabled state and the continuous driver current I LED In this case, when the pulse detection signal S3 is present, the fourth switch SW4 may be switched intermittently according to the second switch-on command signal S2. (Modification 3)

[0090] In the embodiment, the target amount is I REF of the drive current I LED in the three states φ2 to φ4. However, the present disclosure is not limited thereto, and the target amount I REF of the drive current I LEDmay be different when the first light source 110 is switched on (φ2) and when the second light source 120 is switched on (φ3 and φ4). In this case, the target amount I REF based on the pulse detection signal S3 or associated signals. (Modification 4)

[0091] In the embodiment, a clearance lamp and a turn signal were described as a combination of a first and a second light source, but the present disclosure is not limited thereto. The combination of the first light source and the second light source may be a tail lamp and a cornering lamp or a brake lamp and a cornering lamp. In this case, the first light source may be replaced from the white semiconductor light source with a red semiconductor light source.

[0092] From the foregoing, it will be appreciated that various exemplary embodiments of the present disclosure have been described herein for illustrative purposes, and that various changes may be made without affecting the scope and spirit of the present disclosure. Accordingly, the various exemplary embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following statements.

Claims

[1] Vehicle lamp (100A), which includes: a first light source (110); a second light source (120); a first input terminal (IN1) receiving a first switch-on command signal (S1), which instructs switching the first light source (110) on and off; a second input terminal (IN2) receiving a pulsed second switch-on command signal (S2) instructing switching on / off of the second light source (120); and a switching circuit (200A) that controls the first light source (110) and the second light source (120) based on the first switching command signal (S1) and the second switching command signal (S2), wherein the switching circuit (200A) comprises: a drive circuit (210A) activated based on the first turn-on command signal (S1) and the second turn-on command signal (S2) and outputting a constant drive current from an output terminal; and a distribution circuit (220A) which forms a current path such that the drive current flows to the second light source (120) in an input state of the second switch-on command signal (S2), and which forms a current path such that the drive current flows to the first light source (110) in a non-input state of the second switch-on command signal (S2), wherein one end of the first light source (110) and one end of the second light source (120) are connected to an output of the drive circuit (210A), the drive circuit (210A) is enabled when at least the first switch-on command signal (S1) and / or the second switch-on command signal (S2) is at an on level, and the distribution circuit (220A) includes: a first switch (SW1) connected to the other end of the first light source (110); a second switch (SW2) connected to the other end of the second light source (120), and a control circuit (222) which, in the non-input state of the second switch-on command signal (S2), turns on the first switch (SW1) and turns off the second switch (SW2), and, in the input state of the second switch-on command signal (S2), turns off the first switch (SW1) and turns on the second switch (SW2) in accordance with the second switch-on command signal (SW2). [2] The vehicle lamp (100A) according to claim 1, wherein the control circuit (222) comprises a pulse detection circuit (224A) that generates a pulse detection signal (S3) that is accepted in the input state of the second turn-on command signal (S2) and negated in the non-input state of the second turn-on command signal (S2), and the control circuit (222) controls the first switch according to the pulse detection signal (S3) and the second switch (SW2) according to the pulse detection signal (S3) and the second turn-on command signal (S2). [3] Vehicle lamp (100B) comprising: a first light source (110); a second light source (120); a first input terminal (IN1) receiving a first switch-on command signal (S1), which instructs switching the first light source (110) on and off; a second input terminal (IN2) receiving a pulsed second switch-on command signal (S2) instructing switching on / off of the second light source (120); and a switching circuit (200B) that controls the first light source (110) and the second light source (120) based on the first switching command signal (S1) and the second switching command signal (S2), wherein the switch-on circuit (200B) comprises: a drive circuit (210B) activated based on the first power-on command signal (S1) and the second power-on command signal (S2) and outputting a constant drive current from an output terminal; and a distribution circuit (220B) which forms a current path such that the drive current flows to the second light source (120) in an input state of the second switch-on command signal (S2), and which forms a current path such that the drive current flows to the first light source (110) in a non-input state of the second switch-on command signal (S2), wherein the first light source (110) and the second light source (120) are connected in series, the drive circuit (210B) is activated (i) when the first switch-on command signal (S1) is at an on level and the second switch-on command signal (S2) is not input, and (ii) when the second switch-on command signal (S2) is at the on level, and the distribution circuit (220B) includes: a third switch (SW3) connected in parallel to the first light source (110), a fourth switch (SW4) connected in parallel to the second light source (120), and a control circuit (222B) that turns off the third switch (SW3) and turns on the fourth switch (SW4) in the non-input state of the second power-on command signal (S2) and turns on the third switch (SW3) and turns off the fourth switch (SW4) in the input state of the second power-on command signal (S2). [4] The vehicle lamp (100B) according to claim 3, wherein the control circuit (222B) comprises a pulse detection circuit (224B) that generates a pulse detection signal (S3) that is accepted in the input state of the second turn-on command signal (S2) and negated in the non-input state of the second turn-on command signal (S2), and only turns on the third switch (SW3) and the fourth switch (SW4) according to the pulse detection signal (S3). [5] Vehicle lamp (100A), which includes: a first light source (110); a second light source (120); a first input terminal (IN1) receiving a first switch-on command signal (S1), which instructs switching the first light source (110) on and off; a second input terminal (IN2) receiving a pulsed second switch-on command signal (S2) instructing switching on / off of the second light source (120); and a switching circuit (200A) that controls the first light source (110) and the second light source (120) based on the first switching command signal (S1) and the second switching command signal (S2), where the switch-on circuit (200A) is configured to: i) immediately switching on the second light source (120) and immediately switching off the first light source (110) when the second switch-on command signal (S2) changes to an on state while the first switch-on command signal (S1) is in the on state, and ii) immediately switching off the second light source (120) and immediately switching on the first light source (110) after a predetermined time when the second switch-on command signal (S2) changes to an off level while the first switch-on command signal (S1) is at the on level, wherein one end of the first light source (110) and one end of the second light source (120) are connected to an output of the drive circuit (210A), the drive circuit (210A) is enabled when at least the first switch-on command signal (S1) and / or the second switch-on command signal (S2) is at an on level, and the distribution circuit (220A) includes: a first switch (SW1) connected to the other end of the first light source (110); a second switch (SW2) connected to the other end of the second light source (120), and a control circuit (222) which, in the non-input state of the second switch-on command signal (S2), turns on the first switch (SW1) and turns off the second switch (SW2), and, in the input state of the second switch-on command signal (S2), turns off the first switch (SW1) and turns on the second switch (SW2) in accordance with the second switch-on command signal (SW2). [6] Vehicle lamp (100B) comprising: a first light source (110); a second light source (120); a first input terminal (IN1) receiving a first switch-on command signal (S1), which instructs switching the first light source (110) on and off; a second input terminal (IN2) receiving a pulsed second switch-on command signal (S2) instructing switching on / off of the second light source (120); and a switching circuit (200B) that controls the first light source (110) and the second light source (120) based on the first switching command signal (S1) and the second switching command signal (S2), wherein the enable circuit (200B) is configured to: i) immediately switching on the second light source (120) and immediately switching off the first light source (110) when the second switch-on command signal (S2) changes to an on state while the first switch-on command signal (S1) is in the on state, and ii) immediately switching off the second light source (120) and immediately switching on the first light source (110) after a predetermined time when the second switch-on command signal (S2) changes to an off level while the first switch-on command signal (S1) is at the on level, wherein the first light source (110) and the second light source (120) are connected in series, the drive circuit (210B) is activated (i) when the first switch-on command signal (S1) is at an on level and the second switch-on command signal (S2) is not input, and (ii) when the second switch-on command signal (S2) is at the on level, and the distribution circuit (220B) includes: a third switch (SW3) connected in parallel to the first light source (110), a fourth switch (SW4) connected in parallel to the second light source (120), and a control circuit (222B) that turns off the third switch (SW3) and turns on the fourth switch (SW4) in the non-input state of the second power-on command signal (S2) and turns on the third switch (SW3) and turns off the fourth switch (SW4) in the input state of the second power-on command signal (S2). [7] Vehicle lamp (100A; 100B) according to one of the preceding claims, wherein the vehicle lamp (100A; 100B) is an LED socket (700).

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