Abstract: A liquid crystal display apparatus including a level conversion circuit in which a high speed operation can be attained and also a small transistor capacity can be obtained. In the liquid crystal display apparatus, a signal circuit for driving pixel elements of a display unit and a scanning circuit are provided. The level conversion circuit is constituted of first and second transistors 111 and 112, the respective gate electrodes of which are connected to a first bias voltage power supply, and third and fourth transistors 121 and 122, the respective gate electrodes of which are connected to a second bias voltage power supply and the respective source electrodes of which are connected to a power supply. The drain electrodes of the first and the second transistors 111 and 112 are connected to the respective drain electrodes of the third and the fourth transistors 121 and 122.

Abstract: To prevent an n-channel thin-film transistor from being deteriorated by hot holes generated in a gate-negative pulse mode, a thin polysilicon film 10 is provided with a p-type semiconductor region 13 in contact with a channel region 14. The p-type semiconductor region 13 is electrically connected to nowhere except the channel region 14. Holes induced on the surface due to a gate-negative pulse are further supplied from the p-type semiconductor region 13. An electric field established by the gate-negative pulse is relaxed by the holes, fewer hot holes are injected into the gate oxide film, and the TFT characteristics are less deteriorated.

Abstract: An improved liquid crystal display apparatus for low power consumption is provided, within each of the regions surrounded by a plurality of scanning electrodes and a plurality of signal electrodes, with a display data holding circuit connected to the corresponding scanning electrodes and signal electrodes, for fetching and storing a display data from the signal electrode in response to a scanning signal; a switching device connected to the display data holding circuit, its switching operation being controlled by the holding circuit; and a display electrode connected to the switching device.