Clock generation circuit

Abstract

Abstract PURPOSE: To minimize even the horizontal shift of the liquid crystal TV screen and thus to enhance the picture quality by producing the sampling clock signals from the horizontal synchronous signals and then securing the synchronization for the sampling timing in each horizontal scanning. CONSTITUTION: Both the frequency and phase control are given to oscillation circuit 34 with the output of phase comparator 31 plus the output of subsequent LPF32. At the same time, the output of circuit 34 or the signal obtained by multiplying and dividing the output of 34 is drawn out in the form of sampling clock 38 of the video signal and horizontal synchronous oscillation output 37. With use of these signals, the synchronization is secured for the video signal sampling timing on each horizontal line, and also the timing has assured synchronization to the same picture element with each frame. As a result, the contour blur is reduced on the TV screen, at the same time enhancing the resolution greatly. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Satoru Yazawa
• 👤 Minoru Hosokawa
• 👤 Katsuyuki Ikeda

Bibliographic Details