JPS58110333A - Instrument illuminating apparatus of car - Google Patents

Abstract

PURPOSE:To obtain the captioned apparatus which is provided with safety and free from troubles on operation by providing a means with which the voltage is automatically varied from the higher voltage for a bright illumination in the early stage of illumination for instruments to the lower voltage for permitting confirmation of instruments after the lapse of a prescribed time with high voltage. CONSTITUTION:When a switch 10 is closed, the voltage of battery 9' is supplied into an illumination element 8 through a timer circuit 12, voltage adjusting circuit 13, and a voltage selectting circuit 15. In the early stage of illumination, the voltage applied onto the illuminating element 8 is the high voltage Va due to the voltage adjusting circuit 13, so the illuminating element 8 illuminates instruments brightly. After that, the voltage adjusting circuit 13 gradually lowers the voltage through the operation of the timer circuit 12, and when the time t1 lapses, the voltage Vb which is suitable for traveling at night and with which instruments can be confirmed certainly is obtained. Therefore, a driver can be grown accustomed to the brightness during said reduction of voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle instrument lighting device for a vehicle having instruments illuminated by lighting elements such as incandescent lamps.

Two types of conventional devices are shown in FIG. / in the figure is an instrument panel of a vehicle such as a car, on which instruments such as a speedometer 2, a tachometer 3, a torsion pressure gauge t, an oil pressure gauge S, a fuel gauge 6, and a water temperature gauge 7 are arranged. . r is a lighting element consisting of a plurality of incandescent lamps, and this allows the instruments to be reliably seen when the vehicle is running at night or in a tunnel. The location has been determined. 9 is a battery which is a voltage supply means, 10 is a switch, and this switch 10
When the lighting element t is closed, the lighting element t emits light, and at the same time, the headlights, taillights, etc. (not shown) provided around the outside of the vehicle are turned on. // is a variable resistor for arbitrarily changing and setting the brightness of the lighting element.

However, in such a conventional device, if you enter a tunnel during daytime driving and turn on the switch 10 to turn on the light, the lighting element will not be bright enough for night driving. There is a problem in that the driver's eyes cannot immediately follow the sudden change from dark to dark and the illumination of the instruments seems dim. Therefore, it is necessary to vary the variable resistor and/or supply a high voltage to brighten the lighting element, and once you get used to it, dim the light again, but this is done while driving. It wasn't actually done.

The present invention has been made by focusing on the second problem of the conventional technology, and provides a method for supplying a high voltage to the lighting element to provide bright illumination in a vehicle having instruments that are illuminated by a lighting element. and a supply voltage changing means for automatically changing the voltage from the high voltage to a lower voltage that allows reliable visibility of at least the instruments after a predetermined period of time has elapsed after the initial lighting. To provide a vehicle instrument lighting device that is rich in functionality and free from troublesome operation.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a system diagram showing one embodiment of the present invention.
For convenience of explanation, the same parts as those of the conventional device shown in the figure are given the same reference numerals, and the explanation thereof will be omitted.

9' is a battery which is a voltage supply means for brightly illuminating the lighting element g; /2 is a timer circuit; 13
is a voltage adjustment circuit which gradually lowers the voltage from a high voltage over time using the timer circuit l to reach a low voltage that causes the illumination element r to emit light at a brightness that allows the instruments to be reliably seen. The timer circuit/2 and the voltage adjustment circuit 13 constitute a supply voltage changing means/1A. /S is a voltage change setting circuit consisting of a variable resistor for manual voltage change setting.

/, 4 are reset circuits for resetting the timer circuit /U and voltage adjustment circuit /3 when the switch 10 is opened.

Next, the operation in one embodiment of the present invention will be explained with reference to FIGS. 3 and 7.

First, when the switch 10 is closed, the battery
The voltage of the timer circuit/2, the voltage adjustment circuit 13,
The voltage is supplied to the lighting element r via the voltage change setting circuit/S. At this initial stage of lighting, the voltage applied to the illumination element is a high voltage Va by the voltage adjustment circuit, as shown in FIG. Therefore, the lighting elements brightly illuminate the instruments. Thereafter, the voltage adjustment circuit/3 gradually lowers the voltage due to the operation of the timer circuit/2, and at time t1, the voltage VbK is changed to be suitable for night driving where instruments can be clearly seen. . Therefore, the driver becomes accustomed to the brightness during this voltage drop. When stopping the illumination, the switch 10 is opened, and at the same time, the reset circuit /l is activated to reset the timer circuit 12 and voltage adjustment circuit 13 in preparation for the next operation.

Further, when it is desired to arbitrarily change the constant illumination state, the voltage change setting circuit/3 can be operated. For example, if the voltage is set to VC at point 5 as shown in the figure, the voltage will reach VC at time t2 after lighting starts and will remain at this level thereafter.

Incidentally, in the embodiment of the present invention described above, the IC is used to gradually lower the voltage, or the high voltage Va is simply reduced after a certain period of time has elapsed.
It goes without saying that the voltage may be changed instantaneously from Vb (or Vc) to a lower voltage Vb (or Vc).

Furthermore, it goes without saying that the lighting element r may be a semiconductor element or other various lighting elements instead of an incandescent lamp.

- As described above, according to the device of the present invention, when the surroundings of the vehicle are dark and the instruments are illuminated, the illumination is bright until the driver gets used to it, and then the brightness is automatically changed to an appropriate level. be done. Therefore, there are effects such as high safety and no troublesome operation.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a conventional device, Fig. 2 is a system diagram showing an embodiment of the device of the present invention, and Figs. 3 and 7 are operating characteristic diagrams showing the operation of an embodiment of the device of the present invention. be. /...Instrument panel, r...Lighting element, 9'...Battery (voltage supply means), 10...Switch, 12
...Timer circuit, /3...Voltage adjustment circuit, ia.
... Supply voltage changing means, /j... Voltage change setting circuit,
/l...Reset circuit. , F72・゛-:2゛2) Representative Patent Attorney Ishito j7c,...12.

Claims (1)

[Claims] In a vehicle having instruments illuminated by a lighting element, a voltage supply means for supplying a high voltage to the lighting element to provide bright illumination; A vehicle instrument lighting device characterized by comprising: supply voltage changing means for automatically changing the voltage to a voltage lower than the voltage so that at least the instruments can be reliably seen.