| 摘要 |
PURPOSE:To accurately compensate the liquid crystal display device in temperature thereby to make the mass production possible by converting the beat frequency, which is obtained with the use of reference oscillators having different two frequency temperature characteristics, into temperature information thereby to accurately detect the temperature. CONSTITUTION:The output of a reference signal source 1 is subjected to frequency division by a frequency dividing circuit 2 and is fed as a one second signal to a time signal producing circuit 3 so that it is fed through a decoder circuit 4 and a display drive circuit 5 to display the time in a display device 6. Beats are generated at a beat circuit 8 with the signal source 1 and a second reference signal source 7, and a drive pulse control circuit 9 responds to the one second signal of the output of circuit 2 as well as the beat frequency to judge within what range the present temperature resides. The resultant information is fed to a drive pulse generating circuit 10. This circuit 10 generates from that information the drive pulse waveforms suitable for the temperature and feeds them to the display circuit 5 thereby to drive the display device 6. |
