Image display apparatus and high voltage driver circuit

Abstract

A driver circuit of an image display apparatus comprises driver circuit with a class A / B push-pull stage (T 3 , T 5 ). The driver circuit contains an n-type pull transistor (T 3 ), an n-type control transistor (T 2 ) with a main current channel terminal coupled to a control electrode of the pull transistor (T 2 ) and a voltage source (V) applying a predetermined voltage over a series connection of the control electrode-main current channel terminals of the control transistor (T 2 ) and the pull transistor (T 3 ). The current from the control transistor (T 2 ) flows to a p-type push transistor (T 5 ) via a current mirror (T 4 , T 5 ). An input transistor (T 1 ) draws all of the current from the control transistor (T 2 ) via a node ( 142 ) between the control transistor (T 2 ) and the pull transistor (T 3 ) to control the ratio between the currents through these transistors (T 2 , T 3 ). The input of the driver circuit has a direct control over the current through the input transistor (T 1 ) that does not include a feedback through the control transistor (T 2 ).

Description

technical field [0001] The present invention relates to an image display device, a high voltage driver circuit for driving a display screen in such a device, and more generally to a high voltage driver circuit. Background technique [0002] A high voltage swinging at a high frequency is required to drive an image display screen device such as a CRT. The swing of the output can be greater than 100 volts, which makes minimizing the amount of current that causes power dissipation in the driver circuit in the display screen device a task of first importance. Well known techniques for minimizing power dissipation in the driver circuit are , using a class A / B push-pull output stage. A class A / B push-pull output stage is an output stage that sinks some quiescent current but can source more output current than the quiescent current. [0003] The class A / B output stage includes a pull-up transistor connected between the output and the first power supply, and a pull-up transistor co...

AI Technical Summary

Problems solved by technology

However, unless large input currents of both positive and negative polarities are available, the amplifier must rely on current mirror amplification to amplify

Therefore an amplified P-type current mirror must be used in the push-pull stage, which limits the speed of the push-pull stage

This also makes such circuits less favorable for driving display screen devices, as high frequency operation is necessary for such devices

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