DRIVING CIRCUIT FOR COLOR DISPLAY

• Main Author: SEKO KAZUYUKI
• Format: Patent
• Language: English
• Published: 19.11.1990
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CRYPTOGRAPHY; DISPLAY; EDUCATION; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; SEALS

PURPOSE:To allow the free switching of the blue on a CRT display to blue or light blue by selectively operating one-directional conducting elements. CONSTITUTION:Respective circuits of R, B, G operate independently when switches SW1, SW2 are off. Transistors Q1, Q3 turn on and diodes D1, D4 prevent the backflow of a B signal to clamp circuits 1, 3 when only the B signal is inputted while the SW1, SW>=2 are on. Video amplifiers 4 to 6 operate through an emitter follower consisting of Q1 to Q3 and R6 to R8. the outputs thereof are made into the output signals of R, B, G via cut off adjusting circuits 7 to 9. As a result, the red and green phosphors emit light slightly in addition to the blue phosphor on the CRT, thus forming a light blue. The D2, D3 turn off and the operations similar to the case in which the SW1, SW2 are off take place when the B signal and the signals exclusive of the B signal are inputted. The white of the same color tone as the color tone of the white when the SW1, SW2 are off is then displayed on the CRT.