Horizontal position control circuit for high-resolution lcd monitors

Abstract

A horizontal position control circuit for use in high-resolution LCD monitors is disclosed. The horizontal position control circuit comprises a key pad for adjusting horizontal position of an image displayed; a key input controller for invoking a horizontal position control signal in response to input key signal; an analog-to-digital converter for dividing analog video signals by 2N (N=integers) and for converting the divided analog video signals into the corresponding digital video data; a frame memory for storing the digital video data output from the analog-to-digital converter; and a controller in response to the horizontal position control signal to adjust sampling point of the analog-to-digital converter so that the horizontal position is adjusted by unit pixel, and to adjust output timing of write enable signals directed to the frame memory so that the horizontal position is adjusted by multiple pixels. In the fine adjustment mode, the horizontal position is adjusted by the unit pixel, and in the coarse adjustment it is adjusted by multiple pixels. The fine adjustment is performed by controlling sampling point of the ADC block, while the coarse adjustment is performed by controlling write cycles of the frame memory block. The invention provides for an effective control of horizontal position of an image displayed in high-resolution LCD monitors above standard SXGA and UXGA modes by using the coarse adjustment function of the horizontal position controller.