| 摘要 |
PURPOSE:To reduce the voltage level of a column electrode drive circuit consisting of an analog switch which can apply selectively the voltage after applying the bias voltage from the scan side in a write mode of optical information and at the same time to read out the display information by said drive circuit in a read mode of display information. CONSTITUTION:Row electrodes 1 and column electrodes 4 are distributed in a matrix form between upper and lower glass substrates, and a liquid crystal material having a thermal/electric-optical effect and a smetic phase is put between both substrates. A row electrode drive circuit 33 consists of a group of plural switches 3. These elements 3 usually consists of PNP transistors, for example, to withstand high voltage and a large current in terms of the heating conditions of a liquid crystal layer provided on the electrodes 4. The bias voltage VSC is applied from the side of the electrode 1 in a writing mode of the optical information. Thus it is possible to use a conventional CMOS analog switch of low breakdown strength to a column electrode drive circuit 31. This contributes to the miniaturization of a peripheral drive circuit. The breakdown strength of a switch element for conduction can be reduced since a switch for application of bias voltage is set at the side of said switch element.
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