JPH02141347A - Illumination of display lamp lighting circuit regulatable of brightness of dash board for automobile - Google Patents

Abstract

PURPOSE:To enable ensurance of given brightness for illumination through control of a brightness regulating knob by a method wherein the brightness regulating range of the desired illumination or display lamp of a plurality of illumination or display lamps is differed from that of other illumination or display lamp to prevent darkness from being reduced to a value lower than a given value. CONSTITUTION:A current from a DC source 2 is fed to all illumination or display lamps 1a, 1b, 1c..., 1n... through a common wiring 10. Meanwhile, after a current flow ing out from the illumination or display lamps 1a, 1b, 1c... flows directly to a drive element 4 of a brightness regulating means 3, it is returned to the low potential side of the DC source 2. A current flowing out from the desired illumination or display lamp 1n is branched into a current flowing to the drive element 4 through a diode 7 for preventing a reverse flow and a current flowing to a resistor 8 for bypass, and thereafter, the currents are returned to the low potential side of the DC source 2. By regulating an energizing current to the drive element 4 through control of a bright ness regulating knob 6, the intensity of brightness of the illumination or display lamps 1a, 1b, 1c..., 1n... is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a lighting circuit for lighting or indicator lights whose brightness can be adjusted in an instrument panel of an automobile or the like.

(Prior Art) In recent years, in many automobile instrument panels, the illumination or indicator lights of scales, pointers, etc., and the illuminations or indicator lights of operation switches, regulators, etc., are becoming increasingly adjustable in brightness. .

In order to be able to adjust brightness and darkness in this way, conventionally, as shown in FIG. 5, for example, a plurality of lights or indicator lights 1a are connected in parallel.

A brightness adjusting means 3 is interposed between Ib, lc, . . . , In, . . . and the DC power supply 2. The brightness/darkness adjustment means 3 can be of the so-called electronic type, in which a variable resistor is used directly or the operation of a drive element 4 such as a transistor is adjusted by a variable resistor 5; There are those that continuously adjust the current and those that adjust the switching duty ratio of the drive element 4.

(Problems to be Solved by the Invention) As mentioned above, conventionally, a plurality of illuminations or indicator lights 1a, lb, corresponding to scales, pointers, operation switches, regulators, etc.
lc, . . . , In, . It cannot be made different from the brightness adjustment range of lighting or indicator lights. Therefore, when the brightness adjustment knob 6 is operated to set the illumination or display to the darkest state, the illumination or indicator light 1n of the brightness adjustment knob 6n will also become the darkest, and the next time the brightness adjustment knob 6 is operated, the brightness adjustment knob 6 will be visible. This causes the inconvenience that it becomes difficult.

The present invention aims to solve the above problems, namely:
The brightness adjustment range of the lighting or indicator light corresponding to a desired component such as the brightness adjustment knob 6 on the instrument panel of an automobile is made different from the brightness adjustment range of other lighting or indicator lights, and Although the corresponding illumination or indicator light can be adjusted up to a predetermined darkness, it is designed to ensure a predetermined brightness by preventing the darkness from becoming darker than that.

(Means for Solving the Problems) The configuration of the present invention will be explained with reference to drawings corresponding to embodiments. First, a lighting circuit according to claim 1 includes a plurality of lighting or indicator lights 1a, lb. .

In a lighting circuit in which a brightness adjustment means 3 is interposed between lc, ..., 1n, ... and a DC power source 2, a desired illumination or indicator light In has one side connected to a backflow prevention diode. 7 to one side of the DC power supply 2 via the brightness adjustment means 3, and a bypass resistor 8 is connected between one side of the DC power supply 2 and one side of the desired illumination or indicator light ln. It is connected.

Next, in the lighting circuit described in item 2, as shown in FIGS. This is configured on the low potential side of the DC power supply 2.

Next, in the lighting circuit described in item 3, as shown in FIGS. 2 and 3, in the lighting circuit described in item 1, the brightness adjustment means 3, the backflow prevention diode 7, and the bypass resistor 8 are This is configured on the high potential side of the DC power supply 2.

Next, in the lighting circuit described in item 4, as shown in FIGS. 9 itself.

Next, in the lighting circuits described in Items 5 and 6, respectively, as schematically shown in FIGS. This is a current variable device that can continuously adjust the energizing current, and a switching device that can adjust the switching duty ratio of the drive element 4 using the variable resistor 5.

(Actions and Examples) Next, the operation of the present invention will be explained based on the illustrated embodiment.

First, in the configuration shown in FIG. 1, the current flowing out from the high potential side of the DC power supply 2 passes through the common wiring 10 to all the lighting or indicator lights 1a, 1b, as shown by the arrows in the figure.
1 c, -., 1 n, ... and flows through each of them. and illumination or indicator lights 1a, lb.

The current flowing out from lc, . . . directly goes to the brightness adjustment means 3.
The current flows into the drive element 4 of the drive element 4 and flows back to the low potential side of the DC power supply 2, and at the same time flows out of the illumination or indicator light 1n, flows through the drive element 4 through the backflow prevention diode 7.
One flow into the bypass resistor 8 and the other flows into the bypass resistor 8, and the flow flows through each of them and returns to the low potential side of the DC power supply 2.

Then, by operating the brightness adjustment knob 6, the brightness adjustment means 3
All illumination or indicator lights 1a, lb.

It is possible to adjust the current flowing through lc, . . . , ln, .

In such a case, the illumination or indicator lights 1a, lb.

Since the current flowing through lc, . . . is adjusted only by the driving element 4, the darkest state can be achieved by minimizing the current flowing through the driving element 4.

On the other hand, the current flowing through the illumination or indicator lamp 1n is also adjusted by the drive element 4, but at the same time, a predetermined amount of current is constantly flowing through the bypass resistor 8. Even if the flowing current is zero, the predetermined amount of current is flowing through the illumination or indicator light 1n, and therefore other illuminations or indicator lights 1a+1b+I
Even if C, . It should be noted that the current flowing out from the illumination or indicator lamps 1a, lb, lc, . Or indicator light 1a, lb.

The current flowing through 1c is regulated only by the drive element 4, as described above, and does not cause any inconvenience. As described above, it will not be difficult to visually recognize the brightness adjustment knob 6 during the next operation. As can be seen from the above explanation, the resistance value of the bypass resistor 8 is such that when the current flowing through the drive element 4 is minimized, a current that can ensure a predetermined brightness is supplied to the illumination or indicator lamp In. All you have to do is set it up so that you can do it.

In the embodiment shown in FIG. 1 described above, the brightness adjustment means 3, the backflow prevention diode 7, and the bypass resistor 8 are arranged on the low potential side of the current power source 2, as in the embodiment shown in FIG. As shown in FIGS. 2 and 3, even if these are configured on the high potential side, the same operation will occur, only that the direction of current flow will be reversed. In the embodiments shown in FIGS. 1 and 2, the bright/dark adjusting means 3 is a current variable device or a variable resistor 5 that can continuously adjust the current flowing through the drive element 4 using a variable resistor 5.
This schematically represents a switching device that can adjust the switching duty ratio of the drive element 4. In addition, as shown in FIGS. The operation is similar to that described above. Furthermore, the lighting circuit of the present invention is shown in FIGS.
Of course, as shown in the figure, the low potential side of the DC power supply 2 may be grounded, or the high potential side thereof may be grounded. Furthermore, as described above, the illumination or indicator light that is the object of ensuring a predetermined brightness is the brightness adjustment knob 6.
In addition to the illumination or indicator light in corresponding to the above, other desired illumination or indicator light 1n' may be used.

(Effects of the Invention) As described above, the present invention makes it possible to adjust the brightness of all illuminations or indicator lights in the illumination or display on an automobile instrument panel, etc., and to adjust the desired configuration of the brightness adjustment knob itself, etc. The brightness adjustment range of the lighting or indicator light corresponding to the element is different from the brightness adjustment range of other lighting or indicator lights, and the lighting or indicator light corresponding to the desired component is adjustable up to a predetermined darkness. Since it is possible to ensure a predetermined brightness by preventing the darkness from becoming darker than that, there is an effect that there is no inconvenience in which it becomes difficult to visually recognize the brightness adjustment knob the next time it is operated. . In addition, the present invention realizes the overcasting effect using a backflow prevention diode and a bypass resistor, so the structure is very simple and low cost compared to the case where it is realized by two independent brightness adjustment means. There is an effect.

[Brief explanation of the drawing]

1 to 4 are schematic circuit diagrams corresponding to embodiments of the present invention, and FIG. 5 is a schematic circuit diagram of a conventional example. Code 1a, lb, lc,...+In+...
Illumination or indicator light, 2... DC power supply, 3... Brightness adjustment means, 4... Drive element, 5, 9... Variable resistor,
6...Bright/dark adjustment knob, 7...Diode for backflow prevention, 8...Resistor for bypass, 10...Common wiring. Figure Figure

Claims (6)

[Claims] (1) In a lighting circuit in which a brightness adjustment means is interposed between a plurality of illuminations or indicator lights and a DC power source, a desired illumination or indicator lamp is connected to the An instrument panel for an automobile, characterized in that it is connected to one side of a DC power source via a brightness/dark adjustment means, and a bypass resistor is connected between one side of the DC power source and one side of the desired illumination or indicator light. Lighting circuit with adjustable brightness or display in etc. (2) In the lighting circuit described in paragraph 1, a brightness adjustment means;
A lighting or indicator lighting circuit with adjustable brightness in an automobile instrument panel, etc., characterized in that a backflow prevention diode and a bypass resistor are configured on the low potential side of a DC power supply. (3) In the lighting circuit described in paragraph 1, a brightness adjustment means,
A lighting or indicator lighting circuit with adjustable brightness in an automobile instrument panel, etc., characterized in that a backflow prevention diode and a bypass resistor are arranged on the high potential side of a DC power supply. (4) In the lighting circuit described in item 1, item 2, or item 3, the brightness adjustment means is a variable resistor itself. or indicator light lighting circuit (5) In the lighting circuit described in item 1, item 2, or item 3, the brightness adjustment means is a current variable device capable of continuously adjusting the current flowing through the drive element using a variable resistor. Lighting circuit for adjustable brightness or display in automobile instrument panels, etc. (6) In the lighting circuit described in item 1, item 2, or item 3, the brightness/dark adjustment means is a switching device capable of adjusting the switching duty ratio of the drive element using a variable resistor. Lighting or indicator lighting circuit with adjustable brightness in automobile instrument panels, etc.