Video adapter and digital image display apparatus

申请公布号：: EP0805430(A1)
申请号：: EP19970302872
申请日期：: 1997.04.25
申请公布日期：: 1997.11.05
申请人：: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
发明人：: SAKAMI, HIROYUKI;MAIGUMA, HIDEKI
分类号：: G09G3/20;G09G3/36;G09G5/00;G09G5/18
主分类号：: G09G3/20
摘要：: A video adapter (VA) converts an analog image signal (Sia) output from a personal computer to a digital signal (Sid). The clock frequency (Sc), phase data (Sp), and display position data (Sdc) for the A/D conversion are set automatically according to the analog image signal (Sia) to adjust for any offset. An A/D converter (1) analog/digital converts the analog image signal (Sia) from a digital image signal source. An image start/termination coordinate detection circuit (3) detects the video signal Sid start (HcS) and end (HcE) coordinates of the digital video signal (Sid) from the A/D-converter (1) using the synchronization signals (Hsync and Vsync) and clock (Sc), and then generates coordinate data (Sdc). A clock generation circuit (2) generates the clock (Sc) input to the A/D converter (1) based on the input from the display control circuit (4). A delay circuit (5) delays the horizontal synchronization signal (Hsync) in the input analog image signal (Sia) based on the phase data (Sp) from the display control circuit (4), and further outputs the result to the clock generation circuit (2). A display control circuit (4) calculates the clock count data (Scd), phase data (Sp), and display position data (Sdc) for the image to be displayed based on the coordinate data (Sdc). <IMAGE>