METHOD OF SETTING OPERATING POINT OF TRANSISTOR AND ITS CIRCUIT, METHOD OF CHANGING SIGNAL COMPONENT VALUE AND ACTIVE MATRIX TYPE LIQUID CRYSTAL DISPLAY DEVICE

摘要

PROBLEM TO BE SOLVED: To set the operating point of a MOS transistor having a multigate structure to an operating point where dependency on Vds of Ids or the like is greatly reduced. ;SOLUTION: Data signal voltages on a signal line 102 are held in a voltage holding capacitor 106 through an n type MOS transistor 103 that is turned on by a gate scanning voltage and the voltages are supplied to an analog amplifier circuit 104-1. The circuit 104-1 is constituted of MOS transistors having a double gate structure. The operating point of the transistors is set in an operating range where practically no dependency on Vds of Ids exists. Thus, even though Vds is varied by the response of liquid crystals 109, Ids is approximately made constant. Thus, pixel voltages which are approximately proportional to the data signal voltages are applied to the liquid crystals 109.;COPYRIGHT: (C)2003,JPO