JP2536157B2 - Liquid crystal display - Google Patents

Description

The present invention relates to a liquid crystal display device, and more particularly to a temperature compensating heater for a liquid crystal display device.

[Conventional technology]

The liquid crystal display device has a characteristic that its operating speed rapidly decreases at low temperatures, and the operating temperature range becomes narrow. Therefore, as shown in FIG. 5, a heater electrode 12 is formed on the entire display area of the rear surface of the liquid crystal display panel 11 for compensation at a low temperature, and the heater electrode 12 is heated to heat the liquid crystal and display the liquid crystal. The operating temperature range of the device was widened.

[Problems to be Solved by the Invention]

The temperature compensating heater of the conventional liquid crystal display device described above is
Since it is located outside the liquid crystal display panel, in order to heat the liquid crystal, first, the glass of the liquid crystal display panel was heated, and the liquid crystal was heated by its heat capacity. Therefore, it takes time to heat the glass itself due to the thermal resistance of the glass, and the amount of heat becomes very large. In addition, since the heater electrode is in the entire display area, it is necessary to heat the entire display area, which requires a large amount of heat.

[Means for solving the problem]

The present invention is a thin film transistor, a gate electrode line of the thin film transistor, a display electrode substrate composed of a drain electrode line of the thin film transistor and a display electrode connected to a source electrode of the thin film transistor, a counter electrode substrate composed of a common electrode, In a liquid crystal display device having a liquid crystal sandwiched between a display electrode substrate and the counter electrode substrate,
It is characterized in that a heater electrode is formed on the display electrode substrate. Further, the heater electrode is located below the display electrode. In addition, one terminal of the heater electrode is connected to the gate electrode line, and the other terminal is commonly connected.

〔Example〕

Next, the present invention will be described with reference to the drawings. FIG. 1 is an equivalent circuit diagram of an embodiment of the present invention. The gate and drain of the thin film transistor 1 are the gate electrode line 2 and
The heater electrode 4 is connected to the drain electrode line 3, one terminal of the heater electrode 4 is connected to the gate electrode line 2, and the other terminal thereof is connected to the common terminal 5. The heater electrode 4 is formed corresponding to each gate electrode line 2.

FIG. 2 is a schematic view of an embodiment of the present invention. On the glass substrate (not shown), the gate electrode lines 2 are arranged in the horizontal direction and the drain electrode lines 3 are arranged in the vertical direction. At the intersecting points, there are the thin film transistor 1 and the display electrode 6, and the heater electrode 4 is
It is formed below the display electrodes in parallel with the gate electrode lines 2. An insulating film such as SiO ₂ is provided between the heater electrode 4, the display electrode 6 and the thin film transistor 1 to electrically isolate them.

Next, the operation will be described.
Driven by the voltage waveform as shown in the figure, the thin film transistor is turned on at the high level voltage, and the potential of the drain electrode line is written in the liquid crystal. When a low level potential is applied to the common terminal of the heater electrode, a current flows through the heater electrode only while the gate electrode line is at the high level, the heater electrode generates heat and the liquid crystal is heated to operate at high speed. While the gate electrode line is at the low level, the thin film transistor is in the off state and the electric charge applied to the liquid crystal is retained as it is. On the other hand, both ends of the heater electrode have the same potential and no current flows, so that heat is not generated. As described above, since the thin film transistor and the heater electrode are activated only while the gate electrode line is at a high level, efficient driving is possible.

Further, as shown in FIG. 4, by driving two gate electrode lines at the same time and scanning them sequentially, the amount of heat generated by the heater electrodes can be varied. In this way, it is possible to change the amount of heat generation at an extremely low temperature or a light low temperature to perform optimum driving.

〔The invention's effect〕

As described above, according to the present invention, since the heater electrode is formed on the display electrode substrate and connected to the gate electrode line, the amount of heat applied to the liquid crystal is small, the heating time is short, and the operation speed at low temperature is high. .. Further, since the amount of heat is small, the capacity of the drive circuit and the like can be small, and the power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram of one embodiment of the present invention, FIG. 2 is a schematic diagram of one embodiment of the present invention, and FIGS. 3 and 4 are examples of applied voltage waveforms of gate electrode lines of the present invention. FIG. 5 is a schematic view of a conventional liquid crystal display device. 1 ... Thin film transistor, 2 ... Gate electrode line, 3 ...
Drain electrode wire, 4 ... Heater electrode, 5 ... Common terminal,
6 ... Display electrode, 7 ... Common electrode, 8 ... Liquid crystal, 11 ...
LCD panel, 12 ... Conventional heater electrode.

Claims (1)

(57) [Claims] 1. A display electrode substrate including a thin film transistor, a gate electrode line of the thin film transistor, a drain electrode line of the thin film transistor and a display electrode connected to a source electrode of the thin film transistor, and a counter electrode substrate including a common electrode. In a liquid crystal display device having a liquid crystal sandwiched between the display electrode substrate and the counter electrode substrate, heater electrodes are formed on the display electrode substrate corresponding to each gate electrode line, A liquid crystal display device, wherein one terminal of the heater electrode is connected to a gate electrode line and the other terminal is connected to a common electrode.