Light up the circuit

Abstract

The present invention provides a lighting circuit capable of improving the continuity of lighting, comprising: a first driving circuit, which supplies a first driving current to a first light source including at least one light-emitting element; a detection circuit, which detects whether the light-emitting elements of the first light source have all been lit; a first sending circuit, which sends a first signal based on a detection result indicating that the light-emitting elements of the first light source have all been lit; a first cable, which transmits the first signal from a movable part provided with the first driving circuit, the detection circuit and the first sending circuit to a fixed part; a first receiving circuit, which is provided in the fixed part and receives the first signal via the first cable; and a second driving circuit, which is provided in the fixed part, and when the first receiving circuit receives the first signal, the second driving circuit supplies a second driving current to a second light source, the second light source including at least one light-emitting element and provided in parallel with the first light source.

Description

Technical Field

[0001] The invention relates to a lighting circuit. Background Art

[0002] As a lighting circuit for a vehicle lamp, for example, there is a lighting circuit suitable for a vehicle direction indicator (hereinafter referred to as a "turn signal lamp"), which uses a so-called sequential method in which a plurality of light sources (or light-emitting parts) having light-emitting elements are arranged and lit up in sequence. In addition, as a sequential method, a method of connecting light sources in series and a method of connecting light sources in parallel are known (for example, refer to Patent Document 1). In the case of parallel connection, a circuit (drive circuit) for supplying a drive current is provided corresponding to the light source.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-119449 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, when multiple driving circuits light up light sources connected in parallel in a gradual manner, the timing of lighting up may overlap or be delayed, which may deteriorate the continuity of lighting up. For example, when a turn signal lamp is provided to straddle a fixed portion and a movable portion of a vehicle, the continuity of the timing of lighting up the fixed portion and the movable portion may deteriorate.

[0008] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a lighting circuit capable of improving the continuity of lighting in turn signal lamps connected in parallel.

[0009] Means used to solve problems

[0010] The present invention mainly solves the above-mentioned problems and is a lighting circuit, which is a lighting circuit applied to a vehicle turn signal lamp, and is provided in a fixed part of a vehicle and a movable part that can be opened and closed relative to the fixed part, wherein the lighting circuit comprises: a first driving circuit, which supplies a first driving current to a first light source including at least one light-emitting element; a detection circuit, which detects whether the light-emitting elements of the first light source have all been lit; a first sending circuit, which sends a first signal based on a detection result indicating that the light-emitting elements of the first light source have all been lit; a first cable, which transmits the first signal from the movable part provided with the first driving circuit, the detection circuit and the first sending circuit to the fixed part; a first receiving circuit, which is provided in the fixed part and receives the first signal via the first cable; and a second driving circuit, which is provided in the fixed part and, when the first receiving circuit receives the first signal, the second driving circuit supplies a second driving current to a second light source, the second light source including at least one light-emitting element and provided in parallel with the first light source.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to provide a lighting circuit capable of improving the continuity of lighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a diagram showing an example of a lighting unit 10 mounted on a vehicle 1 .

[0014] Figure 2 1 is a schematic block diagram showing an example of the system configuration of the turn signal lamp 10A.

[0015] Figure 3 This is a schematic block diagram showing an example of the configuration of the lighting circuit 11A.

[0016] Figure 4 4 is a diagram showing an example of the configuration of the linear regulator 42A.

[0017] Figure 5 4 is a diagram showing an example of the configuration of the detection circuit 43A.

[0018] Figure 6 2 is a diagram showing an example of the configuration of the control circuit 46 .

[0019] Figure 7 This is a schematic block diagram showing an example of the configuration of the lighting circuit 11B.

[0020] Figure 8 2 is a diagram showing an example of the configuration of the linear regulator 72A.

[0021] Fig. 9 1 is a diagram showing an example of the voltage detection circuit 76 .

[0022] Fig.10 This is a timing chart for explaining the operation of the lighting circuit 11 .

[0023] Fig.11 It is an explanatory diagram showing the lighting state of the light source 20 and the light source 30 .

[0024] Fig.12 It is an explanatory diagram of the current flowing through the resistor R41 and the resistor R50.

[0025] Fig.13 11 is a schematic block diagram showing an example of a configuration of a lighting circuit 11C as a second embodiment of the lighting circuit 11B.

[0026] Fig.14 This is a timing chart for explaining the operation of the lighting circuit 11 according to the second embodiment.

[0027] Description of Reference Numerals

[0028] 1: Vehicle; 3: Moving part; 4: Fixed part; 10: Lighting unit; 10A: Turn signal lamp; 11, 11A, 11B, 11C: Lighting circuit; 12A, 12B: Cable; 13: Moving unit; 14: Fixed unit; 20: Light source; 21-26: Light emitting part; 30: Light source; 41A, 41B, 41C: PMOSFET; 42A, 42B, 42C: Linear regulator; 43A, 43B, 43C: Detection circuit; 44, 45: I / F circuit; 46: Control circuit; 47: Capacitor; 48: Schottky barrier diode; 49: NMOSFET; 51: Constant current circuit; 52: Disconnection detection circuit; 53: Voltage adjustment circuit; 54: Comparator; 55, 61: PNP transistor; 56, 60, 67: Capacitor; 57, 62: NPN transistor body tube; 63, 64, 65, 66: resistors; 71A, 71B: PMOSFET; 72A, 72B: linear regulator; 73, 77: NMOSFET; 74, 75: I / F circuit; 76: voltage detection circuit; 81: Zener diode; 82, 83: resistors; 91: constant current circuit; 92: disconnection detection circuit; 93: voltage adjustment circuit; 94: comparator; 100: ECU; 110: battery; 120: switch; 461: timer circuit; 462: latch circuit; L1: power line; L2: ground line; A, B, C1~C4, D, E: terminals; D1~D30: light-emitting elements; R1~R15, R41, R42, R43, R50, R51, R52: resistors; Vbat: power supply voltage; VT: steering voltage; S1~S4: signal. DETAILED DESCRIPTION

[0029] At least the following matters are clarified from the description of this specification and the drawings.

[0030] =====First Embodiment======

[0031] <<Configuration of Turn Signal Lamp 10A>>

[0032] Figure 1 1 is a diagram showing an example of a lighting unit 10 mounted on a vehicle 1. Figure 2 1 is a schematic block diagram showing an example of the system configuration of the turn signal lamp 10A.

[0033] exist Figure 1 The vehicle 1 shown in the figure has a fixed portion 4 as a part of the vehicle body and a movable portion 3 (a trunk door in this embodiment) that can be opened and closed relative to the fixed portion 4, which is provided at the rear of the vehicle body. It should be noted that, here, the movable portion 3 is taken as an example of a trunk door, but the present invention is not limited to this. For example, in the case of a hatchback vehicle, the hatchback door corresponds to the movable portion 3.

[0034] The lighting unit 10 is a vehicle lamp installed at the rear of the vehicle 1, and is configured to include a movable unit 13 (tail light (TL) unit) installed at the movable portion 3 and a fixed unit 14 (rear combination lamp (RCL) unit) installed at the fixed portion 4. Figure 1 As shown, the lighting unit 10 is configured symmetrically with respect to the center in the width direction (left-right direction) of the vehicle 1. In the following description, the right side portion (the portion shown in enlarged form) is mainly described, but the left side has the same configuration.

[0035] The lighting unit 10 includes a turn signal lamp 10A. The turn signal lamp 10A is Figure 1 The vehicle turn signal lamp indicated by the oblique lines in the enlarged view of is configured to span the fixed portion 4 and the movable portion 3 of the vehicle 1. It should be noted that the lighting unit 10 includes a tail light, a brake light, etc. in addition to the turn signal lamp 10A. In addition, a wire break detection device (not shown) is provided in the vehicle 1, and the wire break detection device detects whether the light emitting element of the turn signal lamp 10A is broken based on the current input from the battery 110 (described later) to the turn signal lamp 10A.

[0036] like Figure 2 As shown, the turn signal lamp 10A includes a lighting circuit 11 , a light source 20 , a light source 30 , and resistors R1 to R15 .

[0037] The light source 20 is a light source including a light emitting element and is provided on the movable part 3. In the present embodiment, the light source 20 corresponds to the first light source. The light source 20 is divided into six light emitting parts (light emitting part 21 to light emitting part 26). Figure 1 As shown, the six light emitting portions are arranged in parallel in a substantially horizontal direction (the width direction of the vehicle 1 ).

[0038] Light emitting units 21 to 26 are connected in parallel, and light emitting elements connected in series are arranged in parallel in each light emitting unit. For example, in the case of light emitting unit 21, light emitting elements D1 and D2 connected in series are connected in parallel with light emitting elements D3 and D4 connected in series.

[0039] In addition, in each of the light emitting sections 22 to 26, four light emitting elements are provided, similarly to the light emitting section 21. Therefore, the light source 20 is provided with 24 light emitting elements (D1 to D24).

[0040] It should be noted that the configuration of the light-emitting sections 21 to 26 is not limited to the above configuration, as long as each includes at least one light-emitting element. For example, a plurality of light-emitting elements may not be connected in series. In addition, three or more columns of light-emitting elements may be connected in parallel in one light-emitting section. In addition, the number of light-emitting elements, the connection method, etc. may be different in each light-emitting section. In the present embodiment, the light-emitting sections 21 and 22 are equivalent to the first light-emitting section, the light-emitting sections 23 and 24 are equivalent to the second light-emitting section, and the light-emitting sections 25 and 26 are equivalent to the third light-emitting section.

[0041] The light source 30 is a light source that is lit after the light source 20 is lit, and the light source 30 is arranged in the fixed part 4. In the present embodiment, the light source 30 is equivalent to the second light source. The light source 30 is configured with six light-emitting elements (D25 to D30) in series and in parallel. Specifically, the light-emitting element D25, the light-emitting element D26 connected in series, the light-emitting element D27, the light-emitting element D28 connected in series, and the light-emitting element D29, the light-emitting element D30 connected in series are connected in parallel. In addition, the light source 30 is arranged in parallel with the light source 20 of the movable part 3. It should be noted that the structure of the light source 30 is not limited to the above structure, as long as it includes at least one light-emitting element.

[0042] The lighting circuit 11 is applied to the turn signal lamp 10A and lights the light emitting elements of the light sources by supplying drive current to the light sources 20 and 30. The lighting circuit 11 of this embodiment includes a lighting circuit 11A, a lighting circuit 11B, and cables 12A and 12B.

[0043] The lighting circuit 11A is a circuit for lighting each light emitting element of the light source 20, and the lighting circuit 11A is provided in the movable portion 3. The lighting circuit 11B is a circuit for lighting each light emitting element of the light source 30, and the lighting circuit 11B is provided in the fixed portion 4. It should be noted that the configurations of the lighting circuits 11A and 11B will be described later.

[0044] The cable 12A is a cable that transmits a signal (a signal S1 described later) from the movable part 3 to the fixed part 4, and is equivalent to a first cable. The cable 12B is a cable that transmits a signal (a signal S2 described later) from the fixed part 4 to the movable part 3, and is equivalent to a second cable. It should be noted that since the movable part 3 can be opened and closed relative to the fixed part 4, the cables 12A and 12B are wired via the axis portion of the opening and closing of the movable part 3. Therefore, the cables 12A and 12B use longer cables with a length of, for example, 5 to 10 meters.

[0045] Resistors R1 to R15 are resistors for distributing the power consumption of the ICs (specifically, the linear regulators described later) in each lighting circuit. Resistors R1 to R12 are provided in the movable portion 3, and are respectively connected in series between the two light-emitting elements connected in series of the light source 20 and the lighting circuit 11A. In addition, resistors R13 to R15 are provided in the fixed portion 4, and are respectively connected in series between the two light-emitting elements connected in series of the light source 30 and the lighting circuit 11B. It should be noted that, in the present embodiment, a resistor for current control (not shown) is also provided in the IC of the lighting circuit 11, and by setting the resistance value of the resistor for current control, the current value (in other words, the brightness) can be changed for each light-emitting portion (or column of light-emitting elements).

[0046] In addition, Figure 2 In the embodiment, the ECU (electronic control unit) 100 is a control circuit based on a microcomputer or the like provided on the vehicle body side. The lighting circuit 11 (the lighting circuit 11A and the lighting circuit 11B) of the present embodiment lights up the light source 20 and the light source 30 constituting the turn signal lamp in a gradual manner according to the instruction from the ECU 100.

[0047] In addition, Figure 2In the figure, the switch 120 is a component for adding a power source for operating the lighting circuit 11 to the power line L1 of the turn signal lamp 10A. The switch 120 is, for example, a mechanical contact relay, a contactless relay using a semiconductor element, or the like. A power source voltage Vbat of the battery 110 for the vehicle is added to one end of the switch 120, and the other end of the switch 120 is connected to the power source line L1. Therefore, if the switch 120 is turned on based on an instruction from the ECU 100, a power source voltage Vbat is added to the power source line L1. It should be noted that the power source line L1 is a wiring for supplying power to the internal circuit of the lighting circuit 11 (the lighting circuit 11A and the lighting circuit 11B).

[0048] For example, when the driver of the vehicle 1 operates the direction indicator (not shown) to light the turn signal lamp 10A of the lighting unit 10 , the ECU 100 turns the switch 120 on and off at a predetermined cycle Tx. Thus, a voltage having a cycle Tx is applied to the power line L1 of the lighting circuit 11 .

[0049] In addition, the ground line L2 is a wiring for applying a ground level voltage to the internal circuit of the lighting circuit 11 (the lighting circuit 11A and the lighting circuit 11B). The power line L1 and the ground line L2 are respectively branched and connected to the lighting circuit 11A and the lighting circuit 11B. It should be noted that, although the illustration of the ground line L2 is omitted in the following description, it means that in the lighting circuit 11A and the lighting circuit 11B, the grounded part is connected to the ground line L2. In addition, hereinafter, the voltage from the switch 120 applied to the power line L1 is set to the steering voltage VT. Therefore, the steering voltage VT varies between 0V and the power supply voltage Vbat.

[0050] <<Configuration of Lighting Circuit 11A>>

[0051] Figure 3 1 is a schematic block diagram showing an example of the configuration of the lighting circuit 11A. Figure 3 The portion of the movable unit 13 shown except the light source 20 (light emitting units 21 to 26) and the resistors R1 to R12 corresponds to the lighting circuit 11A. The components constituting the lighting circuit 11A are mounted on a substrate (not shown).

[0052] The lighting circuit 11A includes a diode 40, a PMOSFET 41A, a PMOSFET 41B, a PMOSFET 41C, a linear regulator 42A, a linear regulator 42B, a linear regulator 42C, a detection circuit 43A, a detection circuit 43B, a detection circuit 43C, an interface circuit (hereinafter referred to as an I / F circuit) 44, an interface circuit 45, a control circuit 46, a capacitor 47, a Schottky barrier diode 48, an NMOSFET 49, a resistor R41, a resistor R42, and a resistor R43.

[0053] The diode 40 is a device for protecting the circuit from being affected and preventing failure when the battery 110 is connected with wrong polarity (in the case of reverse connection). A steering voltage VT is applied to the anode of the diode 40, and the cathode of the diode 40 is connected to the PMOSFET 41A.

[0054] PMOSFET41A, PMOSFET41B, and PMOSFET41C are elements for supplying power from the power line L1 to the light source 20, and are arranged to be connected in series between the power line L1 (more specifically, the cathode of the diode 40) and the light source 20. The voltage between the PMOSFET41A and the cathode of the diode 40 (node ​​N1) is a value that is a voltage drop amount of the forward voltage of the diode 40 reduced relative to the power supply voltage Vbat, and is set to Vp1 here. PMOSFET41A, PMOSFET41B, and PMOSFET41C control conduction / non-conduction (on-off control) through linear regulators 42A, 42B, and 42C, respectively. In addition, when the power supply voltage Vbat becomes higher than a predetermined value (for example, 11V), PMOSFET41A is adjusted so that the on-resistance becomes larger (described later). It should be noted that PMOSFET41A is equivalent to the first transistor, PMOSFET41B is equivalent to the second transistor, and PMOSFET41C is equivalent to the third transistor.

[0055] The capacitor 47 and the Schottky barrier diode 48 are circuits for surge protection, and are connected in parallel between the PMOSFET 41C and the light source 20 .

[0056] The linear regulators 42A, 42B, and 42C are circuits for generating drive currents based on power from the power line L1 and sequentially supplying the drive currents to the light emitting elements of the light emitting sections of the light source 20 , and are each constituted by an integrated circuit (IC).

[0057] The linear regulator 42A is connected to the light emitting section 21 and the light emitting section 22 of the light source 20, and supplies a driving current to the light emitting elements D1 to D8. The linear regulator 42B is connected to the light emitting section 23 and the light emitting section 24 of the light source 20, and supplies a driving current to the light emitting elements D9 to D16. The linear regulator 42C is connected to the light emitting section 25 and the light emitting section 26 of the light source 20, and supplies a driving current to the light emitting elements D17 to D24. It should be noted that the circuit for supplying a driving current to the light source 20 is not limited to a linear regulator, and other circuits (such as a switching regulator, etc.) may also be used.

[0058] In the present embodiment, the linear regulator 42A is equivalent to the first regulator, the linear regulator 42B is equivalent to the second regulator, and the linear regulator 42C is equivalent to the third regulator. In addition, the linear regulator 42A, the linear regulator 42B, and the linear regulator 42C are equivalent to the first drive circuit. In addition, the drive current supplied to the light-emitting element of the light source 20 by the linear regulator 42A, the linear regulator 42B, and the linear regulator 42C is equivalent to the first drive current. In the present embodiment, three regulators are used to sequentially light up the light-emitting parts of the light source 20, but it is not limited to this. It can also be configured so that all the light-emitting parts included in the light source 20 are sequentially lit by one regulator (drive circuit). The configuration examples of the linear regulator 42A, the linear regulator 42B, and the linear regulator 42C will be described later.

[0059] The detection circuit 43A is a circuit for detecting whether all the light-emitting elements connected to the linear regulator 42A have been lit, and is equivalent to the first detection circuit. The detection circuit 43B is a circuit for detecting whether all the light-emitting elements connected to the linear regulator 42B have been lit, and is equivalent to the second detection circuit. The detection circuit 43C is a circuit for detecting whether all the light-emitting elements connected to the linear regulator 42C have been lit. It should be noted that the detection circuit 43C is equivalent to a detection circuit for detecting whether all the light-emitting elements connected to the first drive circuit (here, the linear regulator 42A, the linear regulator 42B, and the linear regulator 42C) have been lit.

[0060] Based on the detection results of the above detection circuits, the operation of the next linear regulator (in the case of the detection circuit 43C, the linear regulator 72A and the linear regulator 72B on the fixed unit 14 side described later) starts. It should be noted that the configuration examples of the detection circuits 43A, 43B, and 43C will be described later.

[0061] The I / F circuit 44 is a circuit that sends a signal S1 based on the detection result of the detection circuit 43C to the I / F circuit 74 of the fixed unit 14 via the cable 12A. It should be noted that the I / F circuit 44 has an inverter not shown in the figure, and outputs a signal S1 after the logic level of the detection result of the detection circuit 43C is inverted. In the present embodiment, since the output of the detection circuit 43C is a low level (hereinafter referred to as the "L" level), the signal S1 becomes a high level (hereinafter referred to as the "H" level). In the present embodiment, the I / F circuit 44 is equivalent to the first transmission circuit, and the signal S1 at the "H" level is equivalent to the first signal.

[0062] In addition, the I / F circuit 44 applies the signal S1 to the gate of the NMOSFET 49 , and also sends the signal S1 to the control circuit 46 .

[0063] The I / F circuit 45 is a circuit that receives the signal S2 from the I / F circuit 75 on the fixed unit 14 side and sends it to the control circuit 46, and is equivalent to a second receiving circuit. It should be noted that the signal S2 is a signal indicating whether the voltage applied to the light source 30 is higher than a predetermined value (whether preparations for lighting the light emitting element of the light source 30 are completed), and is equivalent to a second signal.

[0064] The control circuit 46 is a circuit that controls the operation of the linear regulator 42A. For example, when the power is turned on, if the I / F circuit 45 receives a signal S2 indicating that the preparation for lighting the light-emitting element of the light source 30 is completed (the voltage applied to the light source 30 is higher than a predetermined value), the linear regulator 42A generates a drive current. In addition, if the control circuit 46 does not receive the above-mentioned signal S2 from the fixed unit 14 within a predetermined period from the I / F circuit 44 sending the signal S1 indicating that the light-emitting parts of the light source 20 have all been lit, the linear regulator 42A is kept in a state of stopping the operation. By stopping the operation of the linear regulator 42A, the PMOSFET 41A is turned off, so the light source 20 on the movable unit 13 side is also extinguished. It should be noted that the configuration example of the control circuit 46 will be described later.

[0065] The resistor R41 is a resistor for adjusting the current value supplied from the battery 110 to the lighting circuit 11A (in other words, adjusting the power consumption), and is connected in parallel to the light source 20 (each light emitting unit).

[0066] NMOSFET49 is connected in series with resistor R41, and signal S1 is applied to the gate. Therefore, NMOSFET49 is turned on and off based on signal S1, and when NMOSFET49 is turned on, current flows through resistor R41. It should be noted that resistor R41 is equivalent to the first resistor, and NMOSFET49 is equivalent to the first switch.

[0067] The resistors R42 and R43 are resistors for dividing the voltage Vp2 of the node N2 between the PMOSFET 41C and the light source 20, and are connected in series between the node N2 and the ground (ground line L2). The voltage Vdiv at the connection point between the resistors R42 and R43 is applied to the comparator 54 (described later) in the linear regulator 42A via the terminal E of the linear regulator 42A.

[0068] <Linear regulator 42A>

[0069] As described above, the lighting circuit 11A is provided with three linear regulators 42A, 42B, and 42C. Hereinafter, the linear regulator 42A will be mainly described as an example, but the linear regulators 42B and 42C also have the same configuration.

[0070] Figure 4 1 is a diagram showing an example of the linear regulator 42A.

[0071] The linear regulator 42A includes a constant current circuit 51, a disconnection detection circuit 52, a voltage adjustment circuit 53, a comparator 54, and a plurality of terminals (terminal A, terminal B, terminal C1 to terminal C4, terminal D, terminal E). In addition, the linear regulator 42A is activated by supplying power (applied voltage Vp1) from a node N1 between the diode 40 of the power supply line L1 and the PMOSFET 41A to the terminals not shown. Therefore, the linear regulator 42A can operate when the steering voltage VT becomes the power supply voltage Vbat regardless of the on / off state of the PMOSFET 41A to the PMOSFET 41C.

[0072] Terminal A is an enable terminal. When a signal of “L” level is applied to terminal A, the linear regulator 42A starts supplying a drive current.

[0073] The terminal B is a terminal for connecting the voltage adjustment circuit 53 to the gate of the PMOSFET 41A. The voltage adjustment circuit 53 adjusts the gate voltage of the PMOSFET 41A via the terminal B.

[0074] Terminals C1 to C4 are terminals for connecting the constant current circuit 51 to each light emitting element of the light emitting section 21 and the light emitting section 22, and are terminals for passing a driving current through each light emitting element. It should be noted that in the linear regulator 42A of the present embodiment, four terminals C1 to C4 are provided as terminals for connecting light emitting elements, but the present invention is not limited thereto, and the number may be three or less, or five or more.

[0075] Terminal D is a terminal for outputting a signal indicating that the gradual change operation in the linear regulator (here, linear regulator 42A) has been completed. In this embodiment, a detection circuit 43A described later detects that a drive current flows through the light emitting element D7 and the light emitting element D8 connected to the terminal C4, and forcibly sets the terminal D to the "L" level. As a result, the terminal A of the next linear regulator (here, linear regulator 42B) becomes the "L" level, and the operation of supplying the drive current starts.

[0076] The terminal E is a terminal for introducing a divided voltage (voltage Vdiv) generated by the resistor R42 and the resistor R43 connected in series to the node N2 of the power supply line L1 into the linear regulator 42A.

[0077] The constant current circuit 51 is a circuit that generates a predetermined drive current based on the power of the power line L1. When generating the drive current, the higher the power supply voltage Vbat, the greater the power consumption (the greater the heat generation). The generated drive current is supplied to the light-emitting unit 21 and the light-emitting element of the light-emitting unit 22 via terminals C1 to C4. It should be noted that in the present embodiment, the linear regulator 42A, the linear regulator 42B, and the linear regulator 42C have the same structure, but the size of the generated drive current is different, for example, depending on the setting of the size of the internal resistance (not shown). Specifically, the drive current generated by the linear regulator 42A is 40mA, the drive current generated by the linear regulator 42B is 60mA, and the drive current generated by the linear regulator 42C is 80mA.

[0078] In addition, a timer (not shown) is provided in the constant current circuit 51, which can stagger the timing of the driving current flowing through the terminals C1 to C4. In this embodiment, after the driving current flows through the terminals C1 and C2 (in other words, the light-emitting elements of the light-emitting unit 21) at the same time, the driving current flows through the terminals C3 and C4 (in other words, the light-emitting elements of the light-emitting unit 22) at a slightly delayed timing (see Fig.10 ). However, the present invention is not limited to this, and for example, the timing may be staggered for each terminal.

[0079] The disconnection detection circuit 52 is a circuit that detects disconnection by connecting the connection lines between the terminals C1 to C4 and the constant current circuit 51. The method for detecting disconnection is not particularly limited, and there are methods such as detecting a voltage rise and detecting a current not flowing.

[0080] The voltage regulating circuit 53 is a circuit that controls the gate voltage of the PMOSFET (here, the PMOSFET 41A). When the linear regulator 42A is activated, the voltage regulating circuit 53 regulates the gate voltage of the PMOSFET 41A via the terminal B to turn on the PMOSFET 41A. Similarly, the voltage regulating circuit 53 of the linear regulator 42B turns on the PMOSFET 41B, and the voltage regulating circuit 53 of the linear regulator 42C turns on the PMOSFET 41C. Moreover, by turning on all of the PMOSFET 41A, the PMOSFET 41B, and the PMOSFET 41C, the light emitting units (the light emitting units 21 to 26) of the light source 20 are in a state where they can be lit.

[0081] It should be noted that when a certain light-emitting element of the light-emitting section 21 and the light-emitting section 22 is turned on, if the light-emitting element is not turned on (when detected by the disconnection detection circuit 52), the linear regulator 42A turns off the PMOSFET 41A through the voltage adjustment circuit 53. Similarly, when a certain light-emitting element of the light-emitting section 23 and the light-emitting section 24 is turned on, if the light-emitting element is not turned on, the linear regulator 42B turns off the PMOSFET 41B. In addition, when a certain light-emitting element of the light-emitting section 25 and the light-emitting section 26 is turned on, if the light-emitting element is not turned on, the linear regulator 42C turns off the PMOSFET 41C. Here, the light-emitting elements of the light-emitting section 21 and the light-emitting section 22 described above correspond to the first light-emitting element, the light-emitting elements of the light-emitting section 23 and the light-emitting section 24 correspond to the second light-emitting element, and the light-emitting elements of the light-emitting section 25 and the light-emitting section 26 correspond to the third light-emitting element.

[0082] Since the PMOSFETs 41A to 41C are connected in series, when any one of them is turned off, current no longer flows through the light source 20 (all the light sources 20 are turned off).

[0083] Furthermore, the voltage adjustment circuit 53 adjusts the gate voltage of the PMOSFET 41A based on the output of the comparator 54 described later (described later).

[0084] The voltage of the E terminal (the voltage Vdiv obtained by dividing the voltage Vp2 by the resistors R42 and R43) is applied to the inverting input terminal (-terminal) of the comparator 54, and the voltage Vref is applied to the non-inverting input terminal (+terminal). Then, the comparator 54 compares the voltage Vdiv with the voltage Vref. In the present embodiment, the level of the voltage Vref and the resistance values ​​of the resistors R42 and R43 are determined so that when the steering voltage VT (power supply voltage Vbat) becomes higher than a predetermined voltage (e.g., 11V), the voltage Vdiv is greater than the voltage Vref.

[0085] When the voltage Vdiv is higher than the voltage Vref, the comparator 54 outputs a signal at an "L" level, and when the voltage Vdiv is lower than the voltage Vref, the comparator 54 outputs a signal at an "H" level. Then, when the output of the comparator 54 is at an "L" level, the voltage adjustment circuit 53 adjusts the gate voltage so that the on-resistance of the PMOSFET 41A becomes larger. As a result, the heat generated in the PMOSFET 41A becomes larger, and the power consumption can be dispersed to the PMOSFET 41A.

[0086] In addition, in the present embodiment, resistors (resistors R1 to R15) are provided between each linear regulator and the light emitting element of each light emitting portion, and further, a resistor R41 is provided in parallel with the light source 20, so that power consumption can be further dispersed. Therefore, when the voltage of the power supply voltage Vbat is large (specifically, when it is 11V or more), the heating of the linear regulator can be suppressed.

[0087] <Detection Circuit 43A>

[0088] Figure 5 FIG. 4 is a diagram showing an example of the configuration of the detection circuit 43A. Figure 5 In FIG. 1 , for the sake of convenience of explanation, the position of terminal D is offset and shown next to terminal C4.

[0089] The detection circuit 43A detects whether current flows through the light-emitting element (here, the light-emitting element D7 and the light-emitting element D8 connected in series) to which the driving current is supplied last among the multiple light-emitting elements D1 to D8 connected to the linear regulator 42A. Specifically, the detection circuit 43A detects whether the light-emitting elements D1 to D8 of the light-emitting units 21 and 22 are all lit based on the voltage Vp2 of the line LA on the anode side (anode side of the light-emitting element D7) and the voltage Vp3 of the line LB on the cathode side (cathode side of the light-emitting element D8) of the light-emitting elements D7 and D8 connected in series. It should be noted that the line LA is equivalent to the first line, and the line LB is equivalent to the second line. Figure 5 As shown, the detection circuit 43A includes a PNP transistor 55, a capacitor 56, an NPN transistor 57, and resistors R44 and R45.

[0090] The emitter of the PNP transistor 55 is connected to the line LA and is connected to the base of the PNP transistor 55 via the capacitor 56. The base of the PNP transistor 55 is connected to the line LB via the resistor R44. The collector of the PNP transistor 55 is connected to the base of the NPN transistor 57 via the resistor R45.

[0091] The collector of the NPN transistor 57 is connected to a connection line between the terminal D of the linear regulator 42A and the terminal A of the linear regulator 42B. It should be noted that a voltage Vp2 is applied to the connection line. The emitter of the NPN transistor 57 is grounded.

[0092] With the above configuration, when no drive current flows through light emitting elements D7 and D8, PNP transistor 55 is turned off, thereby also turning off NPN transistor 57. Therefore, terminal D of linear regulator 42A and terminal A of linear regulator 42B are applied with voltage Vp2 and become "H" level.

[0093] When the drive current flows through the light emitting element D7 and the light emitting element D8, the PNP transistor 55 is turned on. As a result, the current is supplied to the base of the NPN transistor 57, and the NPN transistor 57 is turned on. Therefore, the terminal D of the linear regulator 42A and the terminal A of the linear regulator 42B are forced to become the "L" level, and the linear regulator 42B starts the operation of supplying the drive current.

[0094] Thus, the detection circuit 43A detects that the column (here, the light emitting element D7 and the light emitting element D8) that is lit last among the columns of light emitting elements connected to the linear regulator 42A has been lit, and starts the operation of the linear regulator 42B. Thus, when a plurality of light emitting units are lit using a plurality of linear regulators, the continuity of the lighting of the plurality of light emitting units can be improved.

[0095] The detection circuit 43B and the detection circuit 43C are also configured in the same manner as the detection circuit 43A, and thus their description is omitted. It should be noted that the detection circuit 43B detects whether all the light-emitting elements D9 to D16 of the light-emitting section 23 and the light-emitting section 24 are lit based on the voltage Vp2 of the line on the anode side (anode side of the light-emitting element D15) and the voltage Vp4 of the line on the cathode side (cathode side of the light-emitting element D6) of the light-emitting element (herein, the light-emitting elements D15 and D16 connected in series) to which the driving current is supplied last among the plurality of light-emitting elements D9 to D16 connected to the linear regulator 42B.

[0096] In addition, the detection circuit 43C detects whether the light-emitting elements D17 to D24 of the light-emitting section 25 and the light-emitting section 26 are all lit based on the voltage Vp2 of the line on the anode side (anode side of the light-emitting element D23) and the voltage Vp5 of the line on the cathode side (cathode side of the light-emitting element D24) of the light-emitting element that is last supplied with the driving current among the multiple light-emitting elements D17 to D24 connected to the linear regulator 42C (here, the light-emitting elements D23 and D24 connected in series).

[0097] <Control Circuit 46>

[0098] Figure 6 2 is a diagram showing an example of the configuration of the control circuit 46 .

[0099] The control circuit 46 is configured to include a timer circuit 461 and a latch circuit 462 .

[0100] The timer circuit 461 receives a signal S1 from the I / F circuit 44, and receives a signal S2 from the I / F circuit 45. The timer circuit 461 does not operate when the power is turned on, but starts counting (becomes in an operating state) when the signal S1 becomes "H" level (the terminal D of the linear regulator 42C becomes "L" level).

[0101] Then, when the signal S2 becomes "L" level within a predetermined period from the start of counting, the timer circuit 461 sets the signal S3 to the node N5 of the latch circuit 462 to "L" level to operate the latch circuit 462. It should be noted that the signal S2 at "L" level is a signal indicating that the preparation for lighting the light emitting element of the light source 30 has not been completed (the voltage applied to the light source 30 is lower than the predetermined value), and its details will be described later.

[0102] On the other hand, if the signal S2 does not become the "L" level within a predetermined period after the timer circuit 461 starts counting, the timer circuit 461 stops operating (is reset).

[0103] The latch circuit 462 includes a capacitor 60, a capacitor 67, a PNP transistor 61, an NPN transistor 62, and resistors 63, 64, 65, and 66. The resistors 63 and 64, and the resistors 65 and 66 are connected in series.

[0104] A voltage Vp1 is applied to one electrode of the capacitor 60, and the other electrode of the capacitor 60 is connected to the base of the PNP transistor 61. As described above, the voltage Vp1 is smaller than the power supply voltage Vbat by the forward voltage of the diode 40. In addition, the resistor 63 is provided in parallel with the capacitor 60.

[0105] The base of the PNP transistor 61 is connected to the collector of the NPN transistor 62 via the resistor 64 , the emitter of the PNP transistor 61 is connected to an electrode at one end of the capacitor 60 , and the collector of the PNP transistor 61 is connected to the base of the NPN transistor 62 via the resistor 65 .

[0106] The emitter of the NPN transistor 62 is grounded, and a signal S3 is input from the timer circuit 461 to a connection node N5 between the collector of the NPN transistor 62 and the resistor 64 .

[0107] An electrode at one end of the capacitor 67 is connected to the base of the NPN transistor 62 , and an electrode at the other end is grounded.

[0108] Furthermore, a connection node N6 between the collector of the PNP transistor 61 and the resistor 65 is connected to the terminal A of the linear regulator 42A. Then, a signal S4 is output from the node N6 to the linear regulator 42A.

[0109] Next, the operation of the control circuit 46 will be described.

[0110] When the power is turned on, that is, when the steering voltage VT is the power supply voltage Vbat, the timer circuit 461 and the latch circuit 462 do not operate, and the PNP transistor 61 and the NPN transistor 62 are turned off regardless of the voltage Vp1. Therefore, when the power is turned on, the signal S4 output from the node N6 is at the "L" level, and the linear regulator 42A starts to operate.

[0111] When all the light emitting parts (light emitting elements) of the light source 20 are lit, the signal S1 becomes "H" level, and the timer circuit 461 operates. Thereafter, if the signal S2 does not become "L" level within a predetermined period, the timer circuit 461 stops operating (is reset). On the other hand, when the signal S2 becomes "L" level within a predetermined period (when the light source 30 is not lit), the output signal of the timer circuit 461 becomes "L" level.

[0112] When the signal S3 (node ​​N5) from the timer circuit 461 becomes the "L" level, the PNP transistor 61 of the latch circuit 462 becomes the on state. As a result, the current flows from the collector of the PNP transistor 61 to the base of the NPN transistor 62 via the resistor 65, and the NPN transistor 62 also becomes the on state. The collector of the NPN transistor 62 is connected to the base of the PNP transistor 61, so the on state of the PNP transistor 61 is maintained. That is, the signal S4 from the node N6 is maintained at the "H" level, and the operation of the linear regulator 42A stops. As a result, the PMOSFET41A is turned off, so all the light-emitting parts of the light source 20 are extinguished. It should be noted that when the direction indicator (not shown) used to flash the turn signal lamp 10A is operated, the latch circuit 462 maintains the signal S4 of the above-mentioned logic level.

[0113] <<Configuration of Lighting Circuit 11B>>

[0114] Figure 7 1 is a schematic block diagram showing an example of the configuration of the lighting circuit 11B. Figure 7The portion of the fixing unit 14 shown except for the light source 30 (light emitting elements D25 to D30) and the resistors R13 to R15 corresponds to the lighting circuit 11B. The components constituting the lighting circuit 11B are mounted on a substrate (not shown).

[0115] The lighting circuit 11B includes a diode 70 , PMOSFET 71A, PMOSFET 71B, a linear regulator 72A, a linear regulator 72B, an NMOSFET 73 , an I / F circuit 74 , an I / F circuit 75 , a voltage detection circuit 76 , and resistors R50 , R51 , and R52 .

[0116] The diode 70 is similar to the diode 40 of the lighting circuit 11A, and is a component for protecting the circuit from being affected and preventing failure when the polarity of the battery 110 is connected incorrectly (in the case of reverse connection). A steering voltage VT (0V to power supply voltage Vbat) is applied to the anode of the diode 70, and the cathode is connected to the PMOSFET 71A.

[0117] PMOSFET71A and PMOSFET71B are elements that function as switches when supplying power to the power line L1 to the light source 30, and are connected in series between the diode 70 and the light source 30. The voltage between the PMOSFET71A and the diode 70 (node ​​N7) is formed into a value (here, voltage Vp6) that is reduced by the voltage drop amount of the forward voltage of the diode 70 relative to the power supply voltage Vbat. PMOSFET71A and PMOSFET71B control conduction / non-conduction (on-off control) through linear regulators 72A and 72B, respectively. In addition, when the power supply voltage Vbat becomes higher than a predetermined value (for example, 11V), the PMOSFET71A is adjusted by the linear regulator 72A so that the on-resistance becomes larger.

[0118] The linear regulator 72A and the linear regulator 72B are circuits for generating a drive current based on the power from the power supply line L1 and supplying the drive current to each light emitting element of the light source 30 , and are constituted by an integrated circuit (IC).

[0119] Figure 8 72A. The linear regulator 72A includes a constant current circuit 91, a disconnection detection circuit 92, a voltage adjustment circuit 93, and a comparator 94. It should be noted that the constant current circuit 91, the disconnection detection circuit 92, the voltage adjustment circuit 93, and the comparator 94 are respectively connected to the linear regulator 42A ( Figure 4 )'s constant current circuit 51, disconnection detection circuit 52, voltage adjustment circuit 53, and comparator 54 are the same, so their description is omitted.

[0120] The linear regulator 72A supplies a driving current of 105 mA to the light emitting element D29 and the light emitting element D30 connected in series with the terminal C1, and the linear regulator 72B supplies a driving current of 105 mA to the light emitting element D25 and the light emitting element D26 connected in series with the terminal C1 and the light emitting element D27 and the light emitting element D28 connected in series with the terminal C2. The linear regulator 72A and the linear regulator 72B are equivalent to the second driving circuit. In addition, the driving current supplied by the linear regulator 72A and the linear regulator 72B to the light emitting element of the light source 30 is equivalent to the second driving current. In the present embodiment, two regulators are used to light up the light source 30 (the light emitting element D25 to the light emitting element D30), but it is not limited to this. For example, it is also possible to configure the light source 30 to be lit by one regulator.

[0121] The I / F circuit 74 is a circuit that receives the signal S1 via the cable 12A. It should be noted that the I / F circuit 74 has an inverter (not shown) that inverts the logic value of the signal S1 and outputs the signal to the A terminal of the linear regulator 72A and the linear regulator 72B. For example, when the signal S1 is at the "H" level, the signal at the "L" level is output. As a result, the linear regulator 72A and the linear regulator 72B start supplying the driving current at the same time. It should be noted that the I / F circuit 74 is equivalent to the first receiving circuit.

[0122] The I / F circuit 75 detects whether the voltage applied to the light source 30 (the voltage Vp7 of the node N8) is higher than a predetermined voltage, and sends a signal S2 indicating this state. The signal S2 is received by the I / F circuit 45 of the movable unit 13 via the cable 12B. It should be noted that the I / F circuit 75 is equivalent to a second sending circuit. Here, if there is a disconnection in the light source 30, the PMOSFET71A and PMOSFET71B are controlled to be disconnected by the linear regulator 72A and the linear regulator 72B. Moreover, by disconnecting the PMOSFET71A and PMOSFET71B, the voltage Vp7 is reduced to 0V. Therefore, in this case, the I / F circuit 75 sends a signal S2 indicating that the PMOSFET71A and PMOSFET71B are disconnected.

[0123] The resistor R50 and the NMOSFET 73 are connected in series between the power supply line L1 (here, the node N8) and the ground (the ground line L2). The NMOSFET 73 functions as a switch that allows current to flow through the resistor R50, and its on and off are controlled by the voltage detection circuit 76. In addition, the resistor R50 is a resistor for current adjustment to prevent the vehicle side from erroneously detecting that the light emitting element is disconnected when the power supply voltage Vbat is low.

[0124] The voltage detection circuit 76 is a circuit that controls the on and off of the NMOSFET 73 based on the voltage Vp6 of the node N7 (the cathode side of the diode 70). Since the voltage detection circuit 76 is connected to the cathode side of the diode 70, it is not affected even when the battery 110 is connected in reverse. In the present embodiment, when the power supply voltage Vbat is lower than 9.6V, the voltage detection circuit 76 turns on (on) the NMOSFET 73 based on the voltage Vp6 at that time, and when the power supply voltage Vbat is higher than 9.6V, the NMOSFET 73 is non-conductive (off) based on the voltage Vp6 at that time. It should be noted that an example of the configuration of the voltage detection circuit 76 will be described later. In addition, the voltage Vp6 when the power supply voltage Vbat is 9.6V is, for example, 8.9V (9.6-0.7V (forward voltage)).

[0125] The resistor R51 and the resistor R52 are connected in series between the node N8 to which the source of the PMOSFET 71B and the resistor R50 are connected and the ground (ground line L2). In addition, the connection point of the resistor R51 and the resistor R52 is connected to the terminal E of the linear regulator 72A. Thus, similarly to the linear regulator 42A on the movable unit 13 side, when the steering voltage VT (power supply voltage Vbat) becomes higher than a predetermined voltage (for example, 11V), the voltage adjustment circuit 93 of the linear regulator 72A adjusts the gate voltage so that the on-resistance of the PMOSFET 71A becomes larger.

[0126] As a result, the heat generated in PMOSFET71A increases, and the power consumption can be dispersed to linear regulator 72A, linear regulator 72B, and PMOSFET71A. Furthermore, as described above, in the present embodiment, the movable part 3 side is also provided with PMOSFET41A disposed between power line L1 and light source 20, resistor R41 disposed between PMOSFET41A and ground (ground line L2), and linear regulator 42A that increases the on-resistance of PMOSFET when power supply voltage Vbat is greater than a predetermined value. As a result, the power consumption can be dispersed to PMOSFET41A and resistor R41 on the light source 20 (movable part 3) side. Therefore, the power consumption can be further dispersed.

[0127] <Voltage Detection Circuit 76>

[0128] Fig. 9 2 is a diagram showing an example of the configuration of the voltage detection circuit 76 . Fig. 9 The voltage detection circuit 76 includes a Zener diode 81 , a resistor 82 , a resistor 83 , a resistor 86 , and an NPN transistor 85 .

[0129] The Zener diode 81 and the resistors 82 and 83 are connected in series between the node N7 of the power line L1 and the ground (ground line L2). The Zener diode 81 adjusts the relationship between the voltage between the resistors R82 and R83 connected in series and the threshold voltage of the NPN transistor 85. The resistors R82 and R83 divide the voltage Vp6 after the voltage is reduced by the Zener diode 81. It should be noted that the Zener voltage of the Zener diode 81 and the resistance values ​​of the resistors R82 and R83 are determined so that when the power supply voltage Vbat is higher than a predetermined value (9.6V in this embodiment), the NPN transistor 85 is turned on, and when the power supply voltage Vbat is lower than a predetermined value, the NPN transistor 85 is turned off.

[0130] The base of the NPN transistor 85 is connected between the resistors R82 and R83 connected in series. The emitter of the NPN transistor 85 is grounded, the voltage Vp6 is applied to the collector via the resistor R86, and the collector is connected to the gate of the NMOSFET73.

[0131] With the above configuration, when the power supply voltage Vbat is higher than the predetermined value (9.6 V), the NPN transistor 85 is turned on and the NMOSFET 73 is turned off. Therefore, no current flows through the resistor R50.

[0132] On the other hand, when the power supply voltage Vbat becomes lower than the predetermined value (9.6V), the NPN transistor 85 is turned off. As a result, the NMOSFET 73 is turned on, and a current flows through the resistor R50. As a result, even when the power supply voltage Vbat is lower than the predetermined value (9.6V), the power consumption of the lighting circuit 11B can be increased. As a result, it is possible to prevent the vehicle from erroneously detecting that the light emitting element is disconnected.

[0133] It should be noted that the configuration of the voltage detection circuit 76 is not limited to Fig. 9 The configuration shown may be any configuration as long as it has the same function. For example, a comparator may be used to turn the NMOSFET 73 on and off according to the power supply voltage Vbat.

[0134] <<Operation of Lighting Circuit 11>>

[0135] Fig.10 1 is a timing chart for explaining the operation of the lighting circuit 11. Fig.11 2 is an explanatory diagram showing the lighting state of the light source 20 and the light source 30. Fig.12 is an explanatory diagram of the current flowing through the resistor R41 and the resistor R50. Fig.11 In the figure, the luminous state (brightness) of the luminous part is represented by oblique lines. The more oblique lines there are (the narrower the intervals between the oblique lines), the brighter it is.

[0136] For example, when the direction indicator (not shown) for flashing the turn signal lamp is operated, the ECU 100 of the present embodiment repeatedly turns the switch 120 on and off at a predetermined period Tx (for example, 700 ms). It should be noted that the periods during which the switch 120 is turned on and off in the period Tx are respectively half the period of the period Tx (350 ms). Thus, during the period of half the period Tx, the steering voltage VT is applied to the power line L1. In addition, during the period when the steering voltage VT becomes the H level (the period during which it becomes the power supply voltage Vbat), the period during which the light-emitting parts of the light source 20 are sequentially lit ( Fig.10 During the time period t0 to t7), the input current is small, so there is a risk that the disconnection detection circuit (not shown) provided on the vehicle side will mistakenly detect that the light source 20 or the light source 30 is disconnected. Therefore, during the above period, the disconnection detection circuit on the vehicle side is shielded to not perform detection.

[0137] First, at time t0, the steering voltage VT becomes "H" level, and the power supply voltage Vbat of the battery 110 is applied to the power supply line L1. As a result, the linear regulators of the lighting circuit 11A and the lighting circuit 11B are activated, and a driving current is supplied to the light source 20 and the light source 30. Then, Figure 3 The linear regulator 42A (specifically, the voltage adjustment circuit 53) turns on the PMOSFET 41A. Similarly, the linear regulator 42B turns on the PMOSFET 41B, and the linear regulator 42C turns on the PMOSFET 41C. Thus, the power supply line L1 and the light source 20 are in a conductive state.

[0138] exist Figure 7 Similarly, in the lighting circuit 11B, the linear regulator 72A turns on the PMOSFET 71A, and the linear regulator 72B turns on the PMOSFET 71B. As a result, the power line L1 and the light source 30 are in a conductive state. In addition, the I / F circuit 75 sends an "H" level signal S2 indicating that the voltage applied to the light source 30 is higher than the predetermined voltage (the lighting preparation is completed), and the signal S2 is received by the I / F circuit 45 of the movable unit 13 via the cable 12B and input to the control circuit 46. Based on the "H" level signal S2 indicating that the voltage applied to the light source 30 is higher than the predetermined voltage (the lighting preparation is completed), the control circuit 46 outputs the "L" level signal S4 to the A terminal of the linear regulator 42A. The linear regulator 42A starts the operation of supplying the driving current by inputting the "L" level signal S4 to the A terminal.

[0139] First, at time t1, the linear regulator 42A supplies a driving current of 40 mA (80 mA in total) to each of the two columns of light emitting elements (light emitting element D1, light emitting element D2, light emitting element D3, light emitting element D4) of the light emitting unit 21 via the terminals C1 and C2. As a result, the light emitting unit 21 lights up.

[0140] Next, at time t2, the linear regulator 42A supplies a driving current of 40 mA (80 mA in total) to the two columns of light-emitting elements (light-emitting element D5, light-emitting element D6, light-emitting element D7, and light-emitting element D8) of the light-emitting unit 22 via the terminal C3 and the terminal C4. As a result, the light-emitting unit 22 is lit. It should be noted that when the disconnection detection circuit 52 detects that the light-emitting unit 21 and a certain light-emitting element of the light-emitting unit 22 are not lit, the linear regulator 42A (specifically, the voltage adjustment circuit 53) turns off the PMOSFET 41A. As a result, each light-emitting element of the light source 20 is extinguished.

[0141] In addition, the detection circuit 43A detects that all the light emitting elements of the light emitting section 21 and the light emitting section 22 have been turned on based on the voltage Vp2 and the voltage Vp3 of the light emitting elements (here, the light emitting element D7 and the light emitting element D8) that have been turned on last in the light emitting section 21 and the light emitting section 22, and sets the A terminal of the linear regulator 42B to the "L" level. As a result, the linear regulator 42B starts the operation of supplying the drive current.

[0142] At time t3, the linear regulator 42B supplies a driving current of 60 mA (a total of 120 mA) to each of the two columns of light emitting elements (light emitting element D9, light emitting element D10, light emitting element D11, light emitting element D12) of the light emitting unit 23 via the terminal C1 and the terminal C2. As a result, the light emitting unit 23 lights up brighter than the light emitting units 21 and 22.

[0143] Next, at time t4, the linear regulator 42B supplies a driving current of 60 mA (a total of 120 mA) to each of the two columns of light-emitting elements (light-emitting element D13, light-emitting element D14, light-emitting element D15, and light-emitting element D16) of the light-emitting section 24 via the terminal C3 and the terminal C4. As a result, the light-emitting section 24 is lit with the same brightness as the light-emitting section 23. It should be noted that when any of the light-emitting elements of the light-emitting section 23 and the light-emitting section 24 is not lit, the linear regulator 42B turns off the PMOSFET 41B. As a result, each light-emitting element of the light source 20 is extinguished.

[0144] In addition, the detection circuit 43B detects that all the light emitting elements of the light emitting section 23 and the light emitting section 24 have been turned on based on the voltage Vp2 and the voltage Vp4 in the lines at both ends of the light emitting elements D15 and D16 that were turned on last in the light emitting section 23 and the light emitting section 24, and sets the A terminal of the linear regulator 42C to the "L" level. As a result, the linear regulator 42C starts the operation of supplying the drive current.

[0145] At time t5, the linear regulator 42C supplies a driving current of 80 mA (a total of 160 mA) to each of the two columns of light emitting elements (light emitting element D17, light emitting element D18, light emitting element D19, and light emitting element D20) of the light emitting unit 25 via the terminals C1 and C2. As a result, the light emitting unit 25 lights up brighter than the light emitting units 23 and 24.

[0146] Next, at time t6, the linear regulator 42C supplies a driving current of 80 mA (a total of 160 mA) to each of the two columns of light-emitting elements (light-emitting element D21, light-emitting element D22, light-emitting element D23, and light-emitting element D24) of the light-emitting unit 26 via the terminal C3 and the terminal C4. As a result, the light-emitting unit 26 is lit with the same brightness as the light-emitting unit 25. It should be noted that when any of the light-emitting elements of the light-emitting unit 25 and the light-emitting unit 26 is not lit, the linear regulator 42C turns off the PMOSFET 41C. As a result, each light-emitting element of the light source 20 is extinguished.

[0147] In addition, the detection circuit 43C detects that all the light emitting elements of the light emitting section 25 and the light emitting section 26 (in other words, all the light emitting elements of the light emitting section 20) have been turned on, based on the voltage Vp2 and the voltage Vp5 in the lines at both ends of the light emitting element D23 and the light emitting element D24 that were last turned on in the light emitting section 25 and the light emitting section 26 (in other words, in the light source 20). Then, the detection circuit 43C sends a signal (here, a signal of the "L" level) indicating the detection result to the I / F circuit 44.

[0148] At time t7, the I / F circuit 44 inverts the logic level of the "L" level signal and transmits a "H" level signal S1. The signal S1 is transmitted from the movable portion 3 to the fixed portion 4 via the cable 12A and is received by the I / F circuit 74 of the lighting circuit 11B.

[0149] At time t7, a signal S1 of "H" level is applied to the gate of NMOSFET 49, turning on NMOSFET 49 and causing current to flow through resistor R41. Furthermore, signal S1 is input to control circuit 46, and timer circuit 461 of control circuit 46 starts counting.

[0150] The I / F circuit 74 receives the signal S1 of "H" level, and causes the linear regulator 72A and the linear regulator 72B to start supplying the driving current to the light source 30. The linear regulator 72B supplies a driving current of 105 mA to each of the two columns of light-emitting elements (light-emitting element D25, light-emitting element D26 and light-emitting element D27, light-emitting element D28) of the light source 30. In addition, the linear regulator 72A supplies a driving current of 105 mA to the light-emitting element D29 and the light-emitting element D30 connected in series. Therefore, a total driving current of 315 mA is supplied to the light source 30, and the light source 30 is lit brighter than the light-emitting parts of the light source 20. It should be noted that in the present embodiment, the brightness of the light-emitting parts of the light source 20 and the light source 30 is changed, but it is not limited to this. For example, it can also be lit with the same brightness. In the present embodiment, the light-emitting parts of the light source 20 are connected in parallel with the light source 30, so the brightness can be easily changed.

[0151] Then, when the steering voltage VT changes to the "L" level at time t8, the light sources 20 and 30 are turned off. Thereafter, the same processing is performed according to the cycle Tx of the steering voltage VT.

[0152] It should be noted that, when any of the light emitting elements D25 to D28 of the light source 30 is not lit due to a disconnection, etc., the linear regulator 72B turns off the PMOSFET 71B. Similarly, when the light emitting elements D29 and D30 of the light source 30 are not lit, the linear regulator 72A turns off the PMOSFET 71A. As a result, all the light sources 30 are extinguished. In addition, a signal S2 of, for example, an "L" level indicating that the voltage supplied to the light source 30 is lower than a predetermined value is transmitted from the I / F circuit 75 to the control circuit 46 via the cable 12B and the I / F circuit 45 of the movable part 3.

[0153] If the control circuit 46 receives the signal S2 at the "L" level within a predetermined period after receiving the signal S1 at the "H" level, the signal S4 to the linear regulator 42A is maintained at the "H" level. As a result, the linear regulator 42A stops the operation of supplying the drive current and turns off the PMOSFET 41A. Therefore, the light source 20 is also turned off. Therefore, in the present embodiment, when the light emitting element of the light source 30 is disconnected, when the light source 30 side is not in a state where it can be lit, both the light sources 20 and 30 are turned off.

[0154] Thus, in the lighting circuit 11 of the present embodiment, the detection result (signal S1 at "H" level) indicating that all the light-emitting elements of the light source 20 on the movable part 3 side have been lit is transmitted to the fixed part 4 via the cable 12A, and the drive current starts to be supplied to the light source 30. Thus, even if the light source 20 is connected in parallel with the light source 30, it is possible to avoid overlapping or delaying the timing of lighting. Therefore, it is possible to improve the continuity of lighting. In addition, in the movable part 3, based on the detection result of the detection circuit indicating that all the light-emitting parts connected to each linear regulator have been lit, the supply of the drive current based on the next linear regulator is started. Therefore, it is possible to improve the continuity of lighting.

[0155] In addition, the lighting circuit 11 of the present embodiment is supplied with power (power supply voltage Vbat) from the battery 110, but the power supply voltage Vbat is not always constant, but decreases according to use. Therefore, there is a hidden danger of causing adverse conditions depending on the magnitude of the power supply voltage Vbat. For example, when the power supply voltage Vbat is low (for example, lower than 9.6V), the input current to the lighting circuit 11 becomes smaller, thereby causing the vehicle-side disconnection detection circuit (not shown) to mistakenly detect that a disconnection has occurred in the lighting circuit 11.

[0156] Therefore, in this embodiment, a resistor R50 and an NMOSFET73 are connected in series between the power line L1 of the power supply voltage Vbat applied to the lighting circuit 11B and the ground (ground line L2), and a voltage detection circuit 76 is provided to turn the NMOSFET73 on and off according to the size of the power supply voltage Vbat.

[0157] As described above, the voltage detection circuit 76 turns on the NMOSFET 73 when the power supply voltage Vbat is lower than 9.6V, and turns off the NMOSFET 73 when the power supply voltage Vbat is higher than 9.6V. Fig.10 as well as Fig.12 As shown in FIG. 1 , when the power supply voltage Vbat is lower than 9.6 V, current flows through the resistor R50, and the power consumption increases. Fig.10 As shown, during the period when the disconnection detection circuit on the vehicle side is not shielded (the period from time t7 to t8 when the light source 30 is turned on), the NMOSFET 49 is turned on according to the signal S1, and a current also flows through the resistor R41, thereby preventing false detection. It should be noted that when the light source 30 is not turned on due to a disconnection, the PMOSFET 71A is turned off, and no current flows through the resistor R50. Therefore, power consumption can be reduced.

[0158] On the other hand, when the power supply voltage Vbat is high (for example, higher than 11V), the power consumption of each linear regulator of the lighting circuit 11 when generating the drive current increases (the heat generation increases), which may cause a malfunction. In this embodiment, in the lighting circuit 11B, when the power supply voltage Vbat is higher than 11V, the linear regulator 72A adjusts the gate voltage so that the on-resistance of the PMOSFET 71A increases. Thus, the power consumption can be dispersed to the PMOSFET 71.

[0159] It should be noted that, in the lighting circuit 11A, when the power supply voltage Vbat is higher than 11V, the linear regulator 42A adjusts the gate voltage so that the on-resistance of the PMOSFET 41A becomes larger. Thus, the power consumption can be dispersed to the PMOSFET 41A. Fig.10 as well as Fig.12 As shown in FIG. 1 , current also flows through the resistor R41 connected in parallel with the light source 20, so that the power can also be dispersed to the resistor R41. Fig.12 As shown, when the power supply voltage Vbat becomes higher than 11V, the on-resistance of the PMOSFET 41A becomes larger, so the change in the current flowing through the R41 (the slope with respect to the voltage) becomes smaller.

[0160] =======Second Embodiment======

[0161] Fig.13 1 is a schematic block diagram showing an example of the configuration of a lighting circuit 11C as a second embodiment of the lighting circuit 11B. It should be noted that the configuration of the lighting circuit 11A is the same as that of the first embodiment. Fig.13 In the embodiment, the lighting circuit 11B ( Figure 7 ) The parts with the same structure are marked with the same figure marks and the description is omitted.

[0162] The lighting circuit 11C of the second embodiment is different from the lighting circuit 11B of the first embodiment in that it includes a resistor R53 and an NMOSFET 77 .

[0163] The resistor R53 is a resistor for adjusting the value of the current supplied from the battery 110 to the lighting circuit 11C, and is connected in parallel with the light source 30 .

[0164] NMOSFET77 is connected in series with resistor R53, and a signal S1 is applied to the gate from I / F circuit 74. Therefore, NMOSFET77 is turned on and off based on signal S1. In this embodiment, when I / F circuit 74 receives signal S1 at "H" level, NMOSFET77 is turned on and current flows through resistor R53. It should be noted that resistor R53 is equivalent to the second resistor, and NMOSFET77 is equivalent to the second switch.

[0165] Fig.14 This is a timing chart for explaining the operation of the lighting circuit 11 of the second embodiment. Since the signal S1 is applied to the gate of the NMOSFET 77, the NMOSFET 77 is turned on and off at the same timing as the NMOSFET 49 of the movable part 3. In other words, the current flows through the resistor R53 at the same timing as the resistor R41 of the movable part 3.

[0166] Specifically, at time t1 to t7 when the light emitting elements of the light source 20 are sequentially lit, the signal S1 is at the "L" level, so the NMOSFET 77 is turned off, and no current flows through the resistor R53. At time t7, the signal S1 becomes the "H" level, the NMOSFET 77 is turned on, and the current flows through the resistor R53. In addition, at time t8, the signal S1 becomes the "L" level, the NMOSFET 77 is turned off, and no current flows through the resistor R53.

[0167] Thus, in the second embodiment, a resistor R53 connected in parallel with the light source 30 is provided in the lighting circuit 11C on the side of the fixed portion 4. During the period when the light source 30 is lit, a current flows through the resistor R53. Thus, the fixed portion 4 can also adjust the input current in a manner of increasing the input current, which can further suppress the vehicle side's disconnection detection circuit (not shown) from erroneously detecting a disconnection. In addition, when the power supply voltage Vbat is higher than 11V, the linear regulator 72A is adjusted so that the on-resistance of the PMOSFET 71A becomes larger. Therefore, the current characteristic of the resistor R53 with respect to the input voltage is similar to that of the fixed portion 4. Fig.12 By providing the resistor R53 in the fixed portion 4 in this way, when the power supply voltage Vbat is high, the power consumption can be further dispersed.

[0168] =====Summary=====

[0169] The lighting circuit 11 of the present embodiment has been described above. The lighting circuit 11 is provided in the fixed portion 4 and the movable portion 3 of the vehicle 1. The linear regulator 42A, the linear regulator 42B, and the linear regulator 42C provided in the movable portion 3 supply a driving current to the light source 20 including the light emitting elements D1 to the light emitting elements D24, and the detection circuit 43C detects whether all the light emitting elements of the light source 20 have been lit. In addition, the I / F circuit 44 sends the signal S1 of the "H" level based on the detection result. When the I / F circuit 74 provided in the fixed portion 4 receives the signal S1 via the cable 12A that transmits the signal S1 from the movable portion 3 to the fixed portion 4, the linear regulator 72A and the linear regulator 72B supply a driving current to the light source 30 provided in parallel with the light source 20. As a result, the light emitting elements of the light source 30 are lit after all the light emitting elements of the light source 20 are lit, so that the continuity of lighting in the movable portion 3 and the fixed portion 4 can be improved.

[0170] In addition, the I / F circuit 75 provided in the fixed part 4 transmits a signal S2 of "H" level when the voltage applied to the light source 30 is higher than the predetermined voltage. When the I / F circuit 45 of the movable part 3 receives the signal S2 via the cable 12B that transmits the signal S2 from the fixed part 4 to the movable part 3, the control circuit 46 causes the linear regulator (here, the linear regulator 42A) to generate a drive current. Thus, after detecting that the steering voltage VT (power supply voltage Vbat) is applied to the power supply line L1 of the light source 30 facing the fixed part 4 (detecting that the preparation for lighting the light source 30 is completed), the drive current can be supplied to the light source 20.

[0171] Furthermore, when the I / F circuit 45 does not receive the signal S2 at the "H" level (when the signal S2 at the "L" level is received) within a predetermined period after receiving the signal S1 at the "H" level, the control circuit 46 causes the linear regulator (here, the linear regulator 42A) to stop supplying the driving current to the light source 20. Thus, when the light source 30 is not lit, the light source 20 on the movable portion 3 side can also be turned off.

[0172] In addition, the control circuit 46 includes a timer circuit 461 and a latch circuit 462. The timer circuit 461 determines whether the I / F circuit 45 receives the signal S2 at the "H" level within a predetermined period from the reception of the signal S1 at the "H" level, and the latch circuit 462 holds the determination result of the timer circuit 461. Thus, the light source 20 can be turned off by the timer circuit 461 and the latch circuit 462 when the light source 30 is not turned on.

[0173] The movable portion 3 is provided with a resistor R41 connected in parallel with the light source 20 and an NMOSFET 49 connected in series with the resistor R41 and turned on by the signal S1. Thus, when the light source 20 is turned on, current can flow through the resistor R41, and the current amount can be adjusted.

[0174] The fixing part 4 of the second embodiment is provided with a resistor R53 connected in parallel with the light source 30 and an NMOSFET 77 connected in series with the resistor R53 and turned on when the I / F circuit 74 receives the signal S1. Thus, the amount of current can also be adjusted on the fixing part 4 side.

[0175] In addition, the light source 20 includes a plurality of light emitting elements connected in parallel, and the detection circuit 43C detects whether all the light emitting elements of the light source 20 have been lit based on the voltage Vp2 of the line on the anode side and the voltage Vp5 of the cathode side of the light emitting element (light emitting element D23, light emitting element D24) to which the driving current is supplied last, through the linear regulator 42C. In this way, it is possible to detect that all the light emitting elements of the light source 20 have been lit.

[0176] In addition, the lighting circuit 11A includes: a linear regulator 42A, which supplies a driving current to the light-emitting section 21 and the light-emitting section 22; a detection circuit 43A, which detects whether the light-emitting elements of the light-emitting section 21 and the light-emitting section 22 are all lit; a linear regulator 42B, which supplies a driving current to the light-emitting section 23 and the light-emitting section 24 arranged in parallel with the light-emitting section 21 and the light-emitting section 22 based on the detection result indicating that the light-emitting elements of the light-emitting section 21 and the light-emitting section 22 are all lit; the detection circuit 43B detects whether the light-emitting elements of the light-emitting section 23 and the light-emitting section 24 are all lit; and a linear regulator 42C, which supplies a driving current to the light-emitting section 25 and the light-emitting section 26 arranged in parallel with the light-emitting section 21 to the light-emitting section 24 based on the detection result indicating that the light-emitting elements of the light-emitting section 23 and the light-emitting section 24 are all lit. Thus, by using a plurality of linear regulators (linear regulator 42A, linear regulator 42B, linear regulator 42C), it is possible to improve the continuity of lighting of each light emitting unit connected in parallel.

[0177] The lighting circuit 11A includes PMOSFET 41A, PMOSFET 41B, and PMOSFET 41C connected in series to a power supply line L1 for supplying power to the light source 20 (light emitting section 21 to light emitting section 26). Furthermore, the linear regulator 42A turns off the PMOSFET 41A when any of the light emitting elements of the light emitting section 21 and the light emitting section 22 is not lit, the linear regulator 42B turns off the PMOSFET 41B when any of the light emitting elements of the light emitting section 23 and the light emitting section 24 is not lit, and the linear regulator 42C turns off the PMOSFET 41C when any of the light emitting elements of the light emitting section 25 and the light emitting section 26 is not lit. Thus, even when one of the light emitting elements of the light emitting section 20 is not lit, all of the light sources 20 (light emitting section 21 to light emitting section 26) can be turned off.

[0178] The above-mentioned embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. In addition, the present invention can be changed and improved without departing from the gist thereof, and the present invention naturally includes equivalents thereof.

Claims

1. A lighting circuit, which is provided at a fixed portion of a vehicle and a movable portion which can be opened and closed relative to the fixed portion and is applied to a direction indicator light for a vehicle, wherein: The lighting circuit comprises: A first driving circuit that supplies a first driving current to a first light source including at least one light-emitting element; a detection circuit for detecting whether all the light emitting elements of the first light source have been lit; a first transmitting circuit that transmits a first signal based on a detection result indicating that all the light emitting elements of the first light source have been lit; a first cable that transmits the first signal from the movable portion provided with the first drive circuit, the detection circuit, and the first transmission circuit to the fixed portion; A first receiving circuit, which is disposed in the fixed portion and receives the first signal via the first cable; as well as The second driving circuit is arranged in the fixed part. When the first receiving circuit receives the first signal, the second driving circuit supplies a second driving current to a second light source. The second light source includes at least one light-emitting element and is arranged in parallel with the first light source.

2. The lighting circuit according to claim 1, wherein: The lighting circuit comprises: a second transmitting circuit, which is disposed in the fixing portion and transmits a second signal when a voltage applied to the second light source is higher than a predetermined voltage; a second cable that transmits the second signal from the fixed portion to the movable portion; a second receiving circuit, which is disposed on the movable part and receives the second signal via the second cable; as well as The control circuit is provided in the movable portion, and causes the first drive circuit to generate the first drive current when the second receiving circuit receives the second signal.

3. The lighting circuit according to claim 2, wherein: When the second receiving circuit does not receive the second signal within a predetermined period after detecting that all the light emitting elements of the first light source have been turned on, the control circuit causes the first driving circuit to stop generating the first driving current.

4. The lighting circuit according to claim 3, wherein: The control circuit comprises: a timer circuit for determining whether the second receiving circuit receives the second signal within the predetermined period after detecting that the first light source has been turned on; as well as A latch circuit holds the determination result of the timer circuit.

5. The lighting circuit according to any one of claims 1 to 4, wherein: The movable part is provided with: A first resistor connected in parallel with the first light source; and A first switch is connected in series with the first resistor and is turned on based on the first signal.

6. The lighting circuit according to any one of claims 1 to 4, wherein: The fixing portion is provided with: a second resistor connected in parallel with the second light source; and The second switch is connected in series with the second resistor and is turned on when the first receiving circuit receives the first signal.

7. The lighting circuit according to any one of claims 1 to 4, wherein: The first light source comprises a plurality of light emitting elements connected in parallel, The first driving circuit sequentially supplies the first driving current to the plurality of light emitting elements respectively. The detection circuit detects whether all the light emitting elements of the first light source are lit based on a voltage between a first line on an anode side and a second line on a cathode side of a light emitting element to which the first drive current is supplied last among the plurality of light emitting elements.

8. A lighting circuit, which is a lighting circuit applied to a direction indicator light for a vehicle, wherein: The lighting circuit comprises: a first regulator that supplies a driving current to a first light-emitting portion including at least one light-emitting element; a first detection circuit for detecting whether all the light emitting elements of the first light emitting portion have been lit; a second regulator that supplies a driving current to a second light emitting unit including at least one light emitting element and arranged in parallel with the first light emitting unit based on a detection result indicating that all the light emitting elements of the first light emitting unit have been lit; a second detection circuit for detecting whether all the light emitting elements of the second light emitting portion have been lit; as well as A third regulator supplies a driving current to a third light-emitting unit including at least one light-emitting element and arranged in parallel with the first light-emitting unit and the second light-emitting unit based on a detection result indicating that all the light-emitting elements of the second light-emitting unit are lit.

9. The lighting circuit according to claim 8, wherein: The lighting circuit includes a first transistor, a second transistor, and a third transistor connected in series to a power line that supplies power to the first light emitting unit, the second light emitting unit, and the third light emitting unit. When the first light emitting element of the first light emitting unit is turned on, the first regulator turns off the first transistor if the first light emitting element is not turned on. When the second light emitting element of the second light emitting unit is turned on, the second regulator turns off the second transistor if the second light emitting element is not turned on. When the third light emitting element of the third light emitting unit is lit, the third regulator turns off the third transistor if the third light emitting element is not lit.

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