JPS5829494Y2 - Vehicle LCD panel device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a liquid crystal display panel device for a vehicle, which is used as a display section of instruments such as a speedometer, a tachometer, and a clock in a vehicle.

In recent years, liquid crystal display panels have been increasingly used to display instruments such as speedometers, tachometers, and clocks in vehicles.These liquid crystal display panels display information such as vehicle speed, engine rotational speed, and time. It is supposed to be done.

However, when the temperature of the liquid crystal display panel becomes low, for example, -20'C to -30°C, the response display time of the liquid crystal becomes longer, and the response time of the liquid crystal display becomes longer, and the speed of the vehicle, the number of revolutions of the engine, and the time. It has the disadvantage that it is no longer able to quickly and accurately follow fluctuations.

This invention eliminates the drawbacks of the conventional ones as mentioned above,
By heating the liquid crystal display panel, it is possible to prevent the temperature of the liquid crystal display panel from decreasing, thereby quickly and accurately following and displaying changes in vehicle speed, engine rotation speed, etc. Another object of the present invention is to provide a liquid crystal panel device for a vehicle that can significantly reduce the power required for heating.

The present invention will be explained in detail below based on embodiments shown in the drawings.

1 is a liquid crystal display device such as a speedometer for a vehicle, and 2
is its liquid crystal display panel.

Segment electrodes 3 are arranged on the liquid crystal display panel 2, and a heater 4 is embedded in the vicinity of the segment electrodes 3.

This heating heater 4 may be heated all the time to improve the responsiveness of the liquid crystal, but if it is constantly heated, the power source of the vehicle, that is, the battery will be discharged, so the present invention is designed to heat the heater 4 at all times to improve the responsiveness of the liquid crystal. It is equipped with a circuit that turns on electricity to heat the vehicle when the temperature drops below the Shindo level during operation.

Next, to describe the circuit, in Fig. 2, 5 is a thermistor, 6 is a switch circuit that closes when the temperature of the liquid crystal display panel 2 or the temperature inside the vehicle becomes, for example, below -200C, and 7 is a switch circuit that closes when the engine operates. A switch circuit 8 is closed, an AND circuit 8 is closed when signals are received from both switch circuits 6 and 7, and 9 is a transistor that is closed by an output from the AND circuit 8.

Therefore, according to this circuit, when the engine is turned on and the temperature in the liquid crystal display panel 2 or the vehicle interior drops below 120 degrees Celsius, the AND circuit 8 and the transistor 9 are closed, so that the heater 4 is not turned on. A current flows, and the heater 4 heats the liquid crystal display panel 2 .

In the above implementation, engine operation was detected via a force sensor that detects the force of engine lubricating oil, but instead of this, it is possible to detect the operation of a tachometer, or to detect the voltage of a generator or regulator. The operation of the engine may be detected through a relay or the like.

Furthermore, when an analog signal is output as a signal for detecting engine operation, it may be passed through the switch circuit 7, and when a digital signal is output, it may be input directly to the AND circuit 8.

Further, when a humidity switch is used instead of the thermistor 5, the switch circuit can be omitted.

As described above, the present invention provides the liquid crystal display panel 2 with a heater 4 that heats the liquid crystal display panel 2, and detects that the temperature of the surrounding liquid crystal display panel or the temperature inside the vehicle has fallen below a predetermined value and sends a signal. and an operation detection switch 7 that detects the operation of the vehicle engine and issues a signal indicating that the engine is in operation.
Since this is a vehicle liquid crystal display panel device in which the heater 4 heats the liquid crystal display panel 2 in response to a signal from When heated, the liquid crystal becomes more responsive and displays clearer images.

Furthermore, since the heater of the liquid crystal display panel 2 is not energized unless the engine is running, it has the advantage of effectively preventing over-discharging of the battery.

[Brief explanation of drawings]

Each of the drawings shows an embodiment of the present invention, and FIG. 1 is a front view of a liquid crystal display device, and FIG. 2 is a heater energization circuit diagram. 1...Liquid crystal display device, 2...Liquid crystal display panel. ,3・
... Segment electrode, 4... Heater, 5... Thermistor, 6, 7... Switch circuit, 8... AND circuit, 9... Transistor.

Claims (1)

[Scope of utility model registration request] The liquid crystal display panel 2 is equipped with a heater 4 for heating the liquid crystal display panel 2, and a temperature detection switch 6 for detecting that the temperature of the surrounding liquid crystal display panel or the temperature inside the vehicle has fallen below a predetermined value and outputting a signal. and an operation detection switch 7 that detects the operation of the engine of the vehicle and issues a signal indicating that the engine is in operation, and the heater 4 heats the liquid crystal display panel 2 in response to the signals from both the detection switches 6.1. Vehicle liquid crystal display panel device.