JP2001051639A - Dark current interrupting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a dark current interrupting device for vehicle to surely interrupt dark currents of a display circuit and also to make the device to be an inexpensive device. SOLUTION: This device is provided with light emitting diodes LED11, LED12, light emitting LED21, LED22, light emitting LED31, LED32, light emitting LED41 LED42 and first switching circuits GS1 to GS4 for green color, first switching circuits RS1 to RS4 for red color, first switching circuits BS1 to BS4 for blue color which are connected in serise with these light emitting diodes, a second switching circuit GS0 for green color, a second switching circuit RS0 for red color, a second switching circuit BS0 for blue color which are connected in series with light emitting diodes of the same color and when ON signals are not generated with respect to the second switching circuits, a power source to be supplied to these first switching circuits and the second switching circuits is interrupted with a single gate circuit AG.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dark current cutoff device for a vehicle, which cuts off a dark current of a display circuit such as a meter for a vehicle.

[0002]

2. Description of the Related Art Conventionally, a display circuit of a vehicle meter or the like has
It has many light emitting diode rows, and there are also a plurality of switching circuits connected in series to the light emitting diode rows. Therefore, the sum of the dark currents in the switching circuit is a current value that cannot be ignored.

[0003]

However, in order to reduce the dark current of each switching circuit, there is a problem that the number of elements used increases and the cost increases.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an inexpensive dark current interrupting device for a vehicle which can surely shut off dark current of a display circuit. Is what you do.

[0005]

According to a first aspect of the present invention, there is provided a dark current interrupting device for a vehicle, which emits light of the same color as a light emitting diode used in a display circuit and a first switching circuit connected in series to the light emitting diode. A second switching circuit that collectively controls the switching of the first switching circuits connected in series to a diode;
When an ON signal is not generated for the switching circuit, power supplied to the first switching circuit and the second switching circuit is cut off by a single gate circuit. Since the first switching circuit and the second switching circuit can be cut off collectively, the device is inexpensive.

[0006] The determination when no ON signal is generated for the second switching circuit according to the present invention may be determined when the small light is not lit. Even at this time, the dark current with a large integral value can be eliminated,
The effect is almost the same as the former.

[0007]

Embodiments of the present invention will be described below.

FIG. 1 is a circuit diagram of a power supply side circuit of a dark current interrupting device for a vehicle according to a first embodiment of the present invention, and FIG. 2 is a display circuit side of the dark current interrupting device for a vehicle according to the first embodiment of the present invention. FIG. 3 is a circuit configuration diagram of FIG.

In FIG. 1, a control circuit ECU comprises a microcomputer or the like, and is operated by a clock pulse obtained from an oscillation circuit X1.

The light-emitting diodes LED11 and LED12, the light-emitting diode LED21 and the light-emitting diode LED22, the light-emitting diode LED31 and the light-emitting diode LED32, the light-emitting diode LED41 and the light-emitting diode LED42 are connected to connectors C1 to C4, respectively. It is a light emitting diode lamp or chip composed of three primary colors of blue, and an arbitrary color can be output to a vehicle meter by mixing these colors. Also, the light emitting diodes LED11 and LED12, the light emitting diode LED2
1, LED22, light-emitting diodes LED31 and LED32, and light-emitting diodes LED41 and LED42 have their common lines connected to the power supply + B.

Although two light emitting diodes are connected in series in this embodiment, the number of connected light emitting diodes in the case of implementing the present invention may be one or more.

Green first switch circuits GS1 to GS4
Are light emitting diodes LED11, LED12, light emitting diodes LED21, LED22, light emitting diode LED31, LE
D32 is a circuit including a switching transistor for controlling switching of the light emitting diode emitting light for green (G) among the light emitting diodes LED41 and LED42. The first switch circuits RS1 to RS4 for red light-emitting diodes LED11, LED12, light-emitting diode LED
This circuit is composed of a switching transistor that controls the switching of the light emitting diode that emits light for red (R) among the LEDs 21, LED 22, light emitting diodes LED 31, LED 32, and light emitting diodes LED 41, LED 42. The first switch circuits BS1 to BS4 for blue light emitting diodes LED11, LED12, LED21, L
It is a circuit including a switching transistor that controls switching of the light emitting diode that emits light for blue (B) among the ED22, the light emitting diodes LED31 and LED32, and the light emitting diodes LED41 and LED42.

The second switch circuit GS0 for green mainly includes a transistor TR1 and a transistor TR2.
By connecting the emitter sides of the first green switch circuits GS1 to GS4 to the ground potential in response to a signal from the control circuit ECU, the first green switch circuits GS1 to GS4 are connected.
GS4 is turned on and released by releasing it.
The second switch circuit for red RS0 mainly comprises a transistor TR3 and a transistor TR4, and the emitters of the first switch circuits for red RS1 to RS4 are collectively connected to the ground potential by a signal of the control circuit ECU. As a result, the first switch circuits RS1 to RS for red
4 is turned on and released by releasing it. The second switch circuit BS0 for blue mainly comprises a transistor TR5 and a transistor TR6, and the emitters of the first switch circuits BS1 to BS4 for blue are collectively connected to the ground potential by the signal of the control circuit ECU. As a result, the blue first switch circuits BS1 to BS4
Is turned on and released by releasing it.

A gate circuit AG composed of transistors is
First switch circuits GS1 to GS4 for green, first switch circuits for red
Switch circuits RS1 to RS4, blue first switch circuits BS1 to BS4, and green second switch circuit GS
0, the second switch circuit for red RS0 and the second switch circuit for blue BS0 are supplied with power for performing a switching operation. The switch circuit SW1 is connected to the gate circuit AG
The gate circuit AG is turned off when the output from is not required. That is, the base of the transistor of the gate circuit AG is set to the ground potential by the "H" signal of the control circuit ECU, and the transistor is turned off when the signal is "H".

The constant voltage circuit ICV includes a control circuit ECU and first switch circuits GS1 to GS4 for green and a first switch circuit for red.
Switch circuits RS1 to RS4, blue first switch circuits BS1 to BS4, and green second switch circuit GS
0, the voltage supplied to the second switch circuit for red RS0 and the second switch circuit for blue BS0 is a constant voltage.
The resistor R1 is a protection resistor for preventing overcurrent, and the diode D1 is for preventing reverse connection. When an overload such as a short circuit occurs on the gate circuit AG side of the resistor R1 for preventing overcurrent, the constant voltage circuit ICV tries to increase its input in order to increase the voltage on the load side. However, the resistance R1
Appears as a voltage drop proportional to the input current,
The voltage on the load side of the constant voltage circuit ICV cannot be increased,
An excessive current does not flow to the load side of the constant voltage circuit ICV.

The signal circuit Tail obtained from the smoke light switch is input to the base of the transistor TR7. When the output of the smoke light signal Tail is an "H" signal, the output of the transistor TR7 is set to "L".
The signal is inverted. The output of the transistor TR7 is input to the base of the transistor TR8,
When the output of R7 is an "L" signal, the transistor TR8 is turned on, and the control circuit ECU is in the operating state. vice versa,
When the output of the smoke light signal Tail is an "L" signal, the transistor TR8 is turned off and the control circuit ECU
Operation is stopped.

The up-side switch S1 and the down-side switch S2 of the color change switch send a pulse signal to an up-down counter built in the control circuit ECU. The up-side switch S1 of the color change switch is a control circuit. The count value of the up / down counter incorporated in the ECU is increased to shift in the purple direction, and the down switch S2 of the color change switch decreases the count value of the up / down counter to shift in the red direction.

Specifically, the coefficient value for changing the up / down counter incorporated in the control circuit ECU by the color change switch has ten levels, and the light emitting diodes LED11, LED12,
Light emitting diodes LED21, LED22, light emitting diode L
ED31, LED32, light emitting diode LED41, LED42
Of the on-time of the duty ratio that determines each color of red, blue, and green is added or subtracted, and as a result, the duty ratio is changed. The control circuit ECU has a built-in up-down counter that is changed in ten steps, and sends a pulse signal to the up-down counter built in the control circuit ECU. The up-side switch S1 of the color change switch is connected to the control circuit ECU. The count value of the up / down counter incorporated in the ECU is increased to shift in the purple direction, and the down switch S2 of the color change switch decreases the count value of the up / down counter to shift in the red direction.

The jumper wires J1 to J8 connected to the pull-up resistor R2 are such that the jumper wires J1 to J4 are "H".
Or “L”. In the case of "H", the corresponding portions of the jumper wires J1 to J4 are connected, and the corresponding portions of the jumper wires J5 to J8 are released. “L”
In this case, the corresponding portions of the jumper lines J1 to J4 are released, and the corresponding portions of the jumper lines J5 to J8 are connected. The "H" and "L" signals of the jumper lines J1 to J4 are connected to the input ports 4 to 7 of the control circuit ECU, and are determined by the signals of the input ports 4 to 7.

Light emitting diodes LED11, LED12, light emitting diodes LED21, LED22, light emitting diode LED
The characteristics of the LED 31, LED 32, and the light emitting diodes LED 41 and LED 42, for example, brightness is divided into six ranks and wavelength is divided into ten ranks, and the characteristics are compensated by map control. For example, when the brightness is 5 ranks, the jumper line J
1. Connect the jumper wire J3 and open the jumper wires J5 and J7. Then, the jumper wires J2 and J4 are also opened, and the jumper wires J6 and J8 are connected. By doing so, the light emitting diodes LED11, LED output as standard
12, LED21, LED22, LED31, LED32, LED41, LE
The on-time of the duty ratio of the PWM signal for setting each color, brightness, and brightness of D42 for red, blue, and green for each of red, blue, and green is determined, and becomes a standard. That is, the light emitting diodes LED11 and LED12, the light emitting diodes LED21 and LED22, and the light emitting diode LE which emit light in the standard state
The characteristics of D31, LED32, and the light emitting diodes LED41, LED42 are made to match the rank determined by the brightness and the wavelength with the standard characteristics of other identical products.

The thus configured dark current cutoff device for vehicle according to the first embodiment of the present invention operates as follows.

When the output of the signal circuit Tail obtained from the switch of the smoke light is an "L" signal, the output of the transistor TR7 becomes an "H" signal, the output of the transistor TR8 becomes an "L" signal, and the control circuit ECU stops. State.

On the other hand, on the side of the constant voltage circuit ICV, the power supply voltage + B is input via the diode D1 and the resistor R1, and the constant voltage output is output to the collector side of the transistor of the gate circuit AG. The gate circuit AG is in the cut-off state because the output of the control circuit ECU to the switch circuit SW1 is in the "L" signal state and is in the on state, whereby the base of the transistor of the gate circuit AG is at a low potential. Therefore, the first switch circuit G for green
S1 to GS4, red first switch circuits RS1 to RS
4. No power is supplied to the first switch circuits BS1 to BS4 for blue, the second switch circuit GS0 for green, the second switch circuit RS0 for red, and the second switch circuit BS0 for blue.

When the output of the signal circuit Tail obtained from the switch of the smoke light is an "H" signal, that is, when the smoke light is on, the output of the transistor TR7 is an "H" signal, and the output of the transistor TR8 is “L”
The signal becomes a signal, and the control circuit ECU enters an operating state.

On the constant voltage circuit ICV side, a diode D1
, A power supply voltage + B is input through a resistor R1, and a constant voltage output is output to the collector side of the transistor of the gate circuit AG. The gate circuit AG is a switch circuit SW1
, The output of the control circuit ECU becomes "H", and the transistor is turned off. As a result, the base of the transistor of the gate circuit AG has a high potential, so that the transistor is turned on. Therefore, the green first switch circuits GS1 to GS4,
First switch circuits RS1 to RS4 for red, first switch circuits for blue
Power is supplied to the switch circuits BS1 to BS4, the second switch circuit for green GS0, the second switch circuit for red RS0, and the second switch circuit for blue BS0.

Here, the second switch circuit GS0 for green color
When the output of the control circuit ECU connected to the base of the transistor TR1 attains an "L" signal state at a predetermined duty ratio, the transistors TR1 and TR2
Is turned on, that is, the green second switch circuit GS0 is turned on. When the green second switch circuit GS0 is turned on, the green first switch circuits GS1 to GS1 to G
S4 denotes light emitting diodes LED11, LED12, light emitting diodes LED21, LED22, light emitting diode LED31,
Of LED32, light emitting diode LED41 and LED42,
A light emitting diode that emits light for green light is turned on.

When the output of the control circuit ECU connected to the base of the transistor TR3 of the second switch circuit for red RS0 becomes "L" at a predetermined duty ratio, the transistors TR3 and TR4 are turned off.
Is turned on, that is, the second switch circuit for red RS0 is turned on. When the second switch circuit for red RS0 is turned on, the first switch circuits for red RS1 to R1 are turned on.
S4 denotes light emitting diodes LED11, LED12, light emitting diodes LED21, LED22, light emitting diode LED31,
Of LED32, light emitting diode LED41 and LED42,
The light emitting diode that emits light for red is turned on.

Then, the second switch circuit BS0 for blue color
When the output of the control circuit ECU connected to the base of the transistor TR3 becomes "L" at a predetermined duty ratio, the transistors TR3 and TR4
Is turned on, that is, the blue second switch circuit BS0 is turned on. When the second switch circuit BS0 for blue is turned on, the first switch circuits BS1 to B for blue are turned on.
S4 denotes light emitting diodes LED11, LED12, light emitting diodes LED21, LED22, light emitting diode LED31,
Of LED32, light emitting diode LED41 and LED42,
A light emitting diode that emits light for blue light is turned on.

The green second switch circuit GS0,
When the output of the control circuit ECU to the second switch circuit for red RS0 and the second switch circuit for blue BS0 becomes an "H" signal state at a predetermined duty ratio, the second switch circuit for green GS0 and the second switch circuit for red Switch circuit RS0,
The second switch circuit BS0 for blue is turned off, and the first switch circuits GS1 to GS4 for green, the first switch circuits RS1 to RS4 for red, and the first switch circuits BS1 to BS4 for blue turn on the light emitting diode LED11. , LED
12, LED21, LED22, LED31, LED32, LED41, LE
Turn off D42.

As described above, in this embodiment, when the output of the signal circuit Tail obtained from the switch of the smoke light is an "L" signal, that is, when the smoke light is not turned on, the control circuit ECU is stopped. State and the output of the control circuit ECU to the switch circuit SW1 is "L".
Since the switch circuit SW1 is turned on, the gate circuit AG is turned off.
Therefore, the first green switch circuits GS1 to GS4
, Red first switch circuits RS1 to RS4, blue first switch circuits BS1 to BS4, green second switch circuit GS0, red second switch circuit RS0,
The supply of power to the blue second switch circuit BS0 is stopped.

Therefore, the light emitting diodes LED11, LED1
2. Light emitting diodes LED21, LED22, light emitting diodes LED31, LED32, light emitting diode LED41, LE
When D42 is turned off, the first switch circuits GS1 to GS4 for green which are the first switch circuits, the first switch circuits RS1 to RS4 for red, the first switch circuits BS1 to BS4 for blue and the second switch circuit are used. Since no power is supplied to the second switch circuit GS0 for green, the second switch circuit RS0 for red, and the second switch circuit BS0 for blue, the dark current can be reduced.

In this embodiment, when the smoke light is not turned on, the light emitting diodes LED11, LED1
2. Light emitting diodes LED21, LED22, light emitting diodes LED31, LED32, light emitting diode LED41, LE
The first switch circuits GS1 to GS4 for green, the first switch circuits RS1 to RS4 for red, and the first switch circuit BS for blue, which are the first switch circuits for controlling lighting of D42.
1 to BS4, a second switch circuit GS0 for green, which is a second switch circuit, and a second switch circuit RS0 for red.
, For interrupting the supply of power to the second switch circuit BS0 for blue. However, the light emitting diode LE
D11, LED12, light emitting diodes LED21, LED22,
Light emitting diodes LED31, LED32, light emitting diode L
When none of the light emitting diodes of the ED 41 and the LED 42 is turned on, the control circuit ECU determines this, and if the output of the control circuit ECU to the switch circuit SW1 at that time is set to the "L" signal state, furthermore, Dark current can be reduced. Next, the embodiment will be described with reference to FIG.

FIG. 3 is a flowchart of the dark current interrupting device for a vehicle according to the second embodiment of the present invention.

This routine is called during execution of the main program of the control circuit ECU. First, step S1
The output ports 8, 9, and 11 determine whether the second switch circuit including the second switch circuit for green GS0, the second switch circuit for red RS0, and the second switch circuit for blue BS0 is completely off. . When outputting the "H" signal to all of the output ports 8, 9, and 11, the output port 12 is set to the "H" signal in step S2. Switch circuit SW1
Is turned off, whereby the gate circuit AG is turned off. Therefore, the first switch circuits GS1 to GS4 for green and the first switch circuits RS1 to RS1 for red are used.
The supply of power to RS4, the first switch circuits BS1 to BS4 for blue, the second switch circuit GS0 for green, the second switch circuit RS0 for red, and the second switch circuit BS0 for blue is stopped.

When outputting the "L" signal to any of the output ports 8, 9, and 11, the output port 12 is set to the "L" signal in step S3. As a result, the switch circuit SW1 is turned on, and the gate circuit AG is turned on. Accordingly, the first switch circuits GS1 to GS4 for green and the first switch circuits RS1 to R for red are used.
S4, power is supplied to the first switch circuits BS1 to BS4 for blue, the second switch circuit GS0 for green, the second switch circuit RS0 for red, and the second switch circuit BS0 for blue. The on / off control of the second switch circuit GS0 for green, the second switch circuit RS0 for red, and the second switch circuit BS0 for blue becomes possible.

As described above, the dark current cutoff device for a vehicle according to the first embodiment includes the light emitting diodes LED11 and LED11.
12, LED21, LED22, LED31, LED32, LED41, LE
D42 and the first switch circuits GS1 to GS1 for green connected in series to the light emitting diodes.
GS4, a first switch circuit RS1 to RS4 for red, a first switch circuit BS1 to BS4 for blue, and a first switch circuit GS1 for green connected in series to light emitting diodes of the same color. To GS4, a first switch circuit for red, RS1 to RS4, and a first switch circuit for blue, BS1 to BS4. Switch circuit RS0,
A second switching circuit comprising a blue second switching circuit BS0, and when no ON signal is generated for the second switching circuit, the first gate circuit AG supplies the first switching signal to the first switching circuit. The power supply to the switching circuit and the second switching circuit is cut off.

Accordingly, the second switch circuit GS0 for green, the second switch circuit RS0 for red, and the second switch circuit for blue for controlling the first switching circuits collectively.
When no ON signal is generated for the second switching circuit composed of the switching circuit BS0, the power supplied to the first switching circuit and the second switching circuit is cut off by a single gate circuit AG. Light emitting diodes LED11, LED12, light emitting diodes LED21, LED22, light emitting diodes LED31, L
Power consumption when the ED 32 and the light emitting diodes LED 41 and LED 42 are not turned on can be minimized.

Here, in the second embodiment, the light emitting diodes LED11, LED12, the light emitting diode LED21, LE
D22, the light emitting diodes LED31, LED32, and the light emitting diodes LED41, LED42 are used to minimize power consumption when they are not turned on. However, as in the first embodiment,
When no ON signal is generated for the second switching circuit including the green second switching circuit GS0, the red second switching circuit RS0, and the blue second switching circuit BS0, the light emitting diodes LED11, LED12, light emitting diode LED21, LED22, light emitting diode LE
The lighting of the light emitting diode consisting of D31, LED32 and the light emitting diodes LED41, LED42 is unnecessary, and it can be the time when the smoke light is not turned on.

In the embodiment of the present invention, the first switch circuits GS1 to GS4 for green, the first switch circuits RS1 to RS4 for red, and the first switch circuit BS for blue.
1 to BS4, green first switch circuits GS1 to GS4 connected in series to light emitting diodes of the same color, and red first switch circuit RS.
1 to RS4, blue first switch circuits BS1 to BS4
GS0, second switch circuit RS0 for red, and second switch circuit B for blue, which collectively perform switching control of a first switching circuit composed of
Although the description has been made on the assumption that the second switching circuit composed of S0 is provided, the present invention can also be used for a circuit in which one of the switching circuits is omitted.

[0040]

As described above, according to the first aspect of the present invention, the light emitting diode used in the display circuit and the first switching circuit connected in series to the light emitting diode have the same color. And a second switching circuit that performs switching control of the first switching circuits connected in series to the light emitting diode, wherein when the ON signal is not generated for the second switching circuit, a single switching circuit is provided. A gate circuit cuts off power supplied to the first switching circuit and the second switching circuit.

Therefore, the first switching circuit and the second switching circuit can be cut off collectively by a single gate circuit, so that the device is inexpensive. In addition, a single gate circuit can shut off power supplied to the first switching circuit and the second switching circuit, and can eliminate dark current on the display circuit side. Particularly, in a display circuit for a vehicle, Since the power source is a limited power source such as a battery, even when a car radio or the like is driven, the dark current of the display circuit can be eliminated, which is effective.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a power supply side circuit of a dark current interrupting device for a vehicle according to a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of a display circuit side of the dark current interrupting device for a vehicle according to the first embodiment of the present invention.

FIG. 3 is a flowchart of a dark current interrupting device for a vehicle according to a second embodiment of the present invention.

[Explanation of symbols]

LED11, LED12, LED21, LED22, LED31,
LED32, LED41, LED42 Light emitting diode GS1 to GS4 First switch circuit for green RS1 to RS4 First switch circuit for red BS1 to BS4 First switch circuit for blue GS0 Second switch circuit for green RS0 Second for red Switch circuit for BS0 Second switch circuit for blue AG gate circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F074 AA01 AA10 BB06 GG07 5C080 AA07 DD26 DD27 DD30 EE25 EE30 FF11 HH14 JJ02 JJ03 KK20 5J055 AX06 AX52 AX66 BX16 CX00 DX03 DX49 DX55 EX06 EX22 FX14 GFX17

Claims (1)

[Claims] 1. A light emitting diode used for a display circuit, a first switching circuit connected in series to the light emitting diode, and the first switching circuit connected in series to a light emitting diode of the same color. And a single gate for shutting off power supplied to the first switching circuit and the second switching circuit when an ON signal is not generated for the second switching circuit. A dark current interrupting device for a vehicle, comprising: a circuit;