Control circuit for display device

Abstract

Abstract PURPOSE:To connect the liquid crystal display device by an interface similar to a multi-mode CRT monitor by incorporating an automatic detecting function for screen modes in a control circuit for liquid crystal display. CONSTITUTION:This control circuit is provided with a logic decision circuit 1 for a vertical synchronizing signal which consists of a 1st frequency dividing circuit 6 receiving a horizontal synchronizing signal HS as a count input and a vertical synchronizing signal VS as a start signal and a 1st latch circuit 7 receiving the vertical synchronizing signal VS as a data input and the output of the 1st frequency dividing circuit 6 as a latch input. Further, the screen mode decision circuit composed of a logic decision circuit 2 for the horizontal synchronizing signal which consists of a 2nd frequency dividing circuit 8 receiv ing a dot clock signal CK as a count input and the horizontal synchronizing signal HS as a start signal and a 2nd latch circuit 9 receiving the horizontal synchronizing signal HS as a data input and the output of the 2nd frequency dividing circuit 8 as a latch input is incorporated. Consequently, the liquid crystal matrix display device which provides the same feeling of use with the multi-mode CRT monitor can be constituted without placing any load on exter nal circuits nor the user.

Inventors

• 👤 Satoshi Arai
• 👤 聡 荒井

Bibliographic Details