Method for setting transistor operating point and circuit therefor, method for changing signal component value and active-matrix liquid crystal display device

摘要

A data signal voltage on a signal line is held in a voltage holding capacitor through an n-type MOS transistor switched on by a gate scan voltage, and supplied to an analog amplifier circuit. The analog amplifier circuit is formed of an MOS transistor having a double gate structure, and the operating point thereof is set at an operating range in which dependence of Ids on Vds is substantially nullified. Even when Vds is varied due to a response of liquid crystal, Ids is substantially fixed. Accordingly, the pixel voltage which is substantially proportional to the data signal voltage can be applied to the liquid crystal.

主权项

1. A method for setting the operating point of a unipolar first transistor, wherein the unipolar first transistor having a multi-gate structure is equivalently achieved by commonly connecting respective gates of plural unipolar second transistors each having a single gate structure and connecting the plural unipolar second transistors to one another in series, an operating point of each single unipolar second transistor having the single gate structure is set at an operating point that the dependence of source-drain current on source-drain voltage is within a permissible range.