JPS6348438Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device for a vehicle, and particularly to a display device for a vehicle that displays various vehicle information in a driver's seat using a lighting device including a self-luminous element that is lit at night.

2. Description of the Related Art Vehicles are equipped with various display devices in order to accurately display various vehicle information such as speed, mileage, engine speed, and navigator information to a driver while driving the vehicle. When the surroundings of the vehicle are bright, such display devices can display vehicle information on the display inside the driver's seat by reflecting the outside light incident on its surface, but it is not possible to obtain sufficient outside light. At night, it is necessary to illuminate the display section using a self-luminous element.

Conventionally, a device shown in FIG. 1 has been used as a vehicle display device that performs nighttime display using such self-luminous elements.

In the figure, the power source from the battery 10 is connected to the fusible link 12 and the ignition switch 14.
The light is supplied to a lighting circuit 16 via a fusible link 18 and a light switch 20 to a night lamp 22 such as a headlamp. A relay coil 24 is connected in parallel with the night lamp 22 in order to operate the illumination circuit 16 and illuminate the display section (not shown) at night when there is insufficient outside light. A relay contact 26 is connected in series with the ignition switch 14. Then, when the light switch 20 is turned on with the ignition switch 14 turned on and the night lamp 22 is turned on, the relay coil 24 is energized and the relay contact 26 is closed, causing current to flow into the lighting circuit 16. is supplied.

The illumination circuit 16 includes a pattern light emitting lamp 28 that illuminates a pattern forming area from the back side of a display board with a display pattern formed on its surface, and an electroluminescent lamp (hereinafter referred to as "EL lamp") that backlights the display board. ) 30, a DC voltage from a battery 10 is applied to the pattern light emitting lamp 28, and a DC voltage from the battery 10 is applied to the EL lamp 30 as an AC voltage via a DC/AC inverter 32. . Further, the illumination circuit 16 is provided with a brightness setting circuit 34 for setting the pattern light emitting lamp 28 and the EL lamp 30 to optimal brightness, and the brightness setting circuit 34 is a variable resistor connected in series to the pattern light emitting lamp 28. 36 and DC/DC converter 3
It has a variable resistor 40 connected in series to the output of 8. The variable resistor 36 sets the brightness of the pattern light emitting lamp 28 by adjusting the current flowing through the pattern light emitting lamp 28.
The variable resistor 40 sets the brightness by adjusting the control voltage to the DC/AC inverter 32, that is, the voltage and frequency applied to the EL lamp 30. Normally, when the brightness of the pattern light emitting lamp 28 and the EL lamp 30 is high, the display section becomes dazzling, while when the brightness is low, the vehicle information displayed on the display section becomes unclear, both of which affect driving operation. Become. Therefore, the variable resistors 36 and 40 are adjusted and fixed so that optimum brightness can be obtained when the vehicle is running at night. Note that instead of setting the brightness using the variable resistors 36 and 40 described above, the brightness can also be set by performing duty control and changing the duty ratio.

However, when the vehicle is stopped, there are more opportunities to view vehicle information on the display than when the vehicle is moving.
Moreover, since there is no problem in driving operation due to the glare of the display as when the vehicle is running, it is necessary to brighten the illumination of the display compared to when the vehicle is running to clearly understand the vehicle information.

However, in the conventional device, as mentioned above, the brightness of each lamp 28, 30 is adjusted and fixed in order to obtain optimal illumination when the vehicle is running at night, so it is difficult to clearly grasp vehicle information when the vehicle is stopped. The disadvantage was that sufficient lighting could not be obtained.

The present invention has been devised in view of the above-mentioned conventional problems, and its purpose is to provide a vehicle display device that allows vehicle information on the display section to be clearly grasped when the vehicle is stopped.

In order to achieve the above object, the present invention provides a vehicle display device that displays various vehicle information in the driver's seat using a lighting device that includes a self-luminous element that is lit at night. The present invention is characterized in that it has a dimming circuit that dims the lighting device based on a vehicle speed signal from a sensor, and increases the illuminance of the lighting device when the vehicle speed decreases below a predetermined value.

Preferred embodiments of the present invention will be described below based on the drawings.

FIG. 2 shows a preferred embodiment of the vehicle display device according to the present invention, and the same parts as those in the conventional example described above are given the same reference numerals and the explanation thereof will be omitted.

The feature of this invention is that it has a vehicle speed sensor that detects the vehicle speed and a dimming circuit that dims the display device based on the vehicle speed signal from the vehicle speed sensor. This is to brighten the illumination of the display device.

That is, the vehicle is provided with a vehicle speed sensor 42 to detect the vehicle speed, and a vehicle speed signal 100 from the vehicle speed sensor 42 is converted into an analog quantity by a D/A conversion circuit 44 and then supplied to a comparator 46 . Then, if the vehicle speed is the reference voltage setting resistor 4
8, 50, the comparator 46 sends a dimming command signal 1 to the dimming circuit 52.
02 is output, and each lamp 28, 30 is dimmed as described below.

The dimming circuit 52 has a current limiting resistor 54 and a voltage limiting resistor 56 connected in series to the variable resistors 36 and 40, respectively.
The brightness of each lamp 28, 30 is adjusted so that optimum illumination can be obtained when the vehicle is running at night when the lamps 4, 56 are connected in series. Relay contacts 58 and 60 are connected in parallel to the current limiting resistor 54 and voltage limiting resistor 56, respectively, in order to increase the brightness of each lamp 28 and 30 so that sufficient illumination of the display section can be obtained when the vehicle is stopped. ing. Therefore, by closing each relay contact 58, 60 and shorting each resistor 54, 56, the current flowing to the pattern light emitting lamp 28 and the EL lamp 30 is reduced.
The voltage and frequency supplied to each lamp 2 increases.
The brightness of 8 and 30 becomes higher, and the illumination of the display unit becomes brighter to the extent that vehicle information can be sufficiently grasped.

Further, the dimming circuit 52 includes a transistor 62 that is turned on by the dimming command signal 102 output from the comparator 46. When the transistor 62 is turned on, the relay coil 66 is excited, and the relay contacts 58 and 60 are closed. Ru. Therefore, when the vehicle decreases below a predetermined speed, each relay contact 58, 60 is closed as described above, and each lamp 2 is closed.
It is understood that 8.30 dimmings are performed.

In addition to the above-described embodiments, similar effects can be obtained even when a needle-type mechanical meter is used as the display section.

As explained above, the present invention includes a vehicle speed sensor that detects the vehicle speed and a dimming circuit that dims the display device based on the vehicle speed signal from the vehicle speed sensor. By brightening the illumination of the display device when the vehicle is stopped, it is possible to clearly understand the vehicle information on the display when the vehicle is stopped.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an example of a conventional vehicle display device, and FIG. 2 is a circuit diagram showing a preferred embodiment of the vehicle display device according to the present invention. 16: lighting circuit, 28: pattern light emitting lamp, 30: EL lamp, 42: vehicle speed sensor,
52...dimmer circuit, 100...vehicle speed signal.

Claims (1)

[Scope of utility model registration request] In a vehicle display device that displays various vehicle information in the driver's seat using a lighting device that includes a self-luminous element that is lit at night, the lighting device is dimmed using a vehicle speed sensor that detects the vehicle speed and a vehicle speed signal from the vehicle speed sensor. What is claimed is: 1. A display device for a vehicle, comprising: a dimming circuit for increasing the illuminance of the lighting device when the vehicle speed decreases below a predetermined value.