| 摘要 |
PURPOSE:To detect temperature with a microcomputer and interrupt power supply after the indication of a temperature abnormality for protecting a liquid crystal panel in a liquid crystal display device using the liquid crystal panel. CONSTITUTION:A comparator circuit 17 constituted of transistors 11 and 12 makes a comparison between the first voltage V1 divided with a thermister 6 and a resistor 7 and the second voltage V2 divided with resistors 8 and 9, on the basis of the temperature characteristic of the thermister 6. An output signal from the circuit 17 is sent to a microcomputer 15. This microcomputer 15 indicates a warning on a liquid crystal display device 2, when temperature becomes equal to or above a certain level, and turns off a semiconductor switch 5. Power supply to the device 2 is thereby interrupted, and the damage of a liquid crystal panel at high temperature is prevented. |
