GRADATION CONTROL CLOCK SIGNAL GENERATING CIRCUIT FOR COLOR DISPLAY DEVICE

• Main Author: KONDO KENICHI
• Format: Patent
• Language: English
• Published: 16.10.1992
• Subjects: ADVERTISING; ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICESUSING STATIC MEANS TO PRESENT VARIABLE INFORMATION; CRYPTOGRAPHY; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; DISPLAY; EDUCATION; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; SEALS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

PURPOSE:To eliminate a color irregularity and to obtain a beautiful full-color display by providing gradation control signals by colors and adjusting the periods of the clock signals for the respective colors by clock signal generating circuits which can be set externally. CONSTITUTION:The gradation control clock signal generating circuits 1-3 for red, green, and blue are provided independently of one another so that red, green, and blue have linear gradations by pulse width modulation corresponding to electrooptic characteristics that red, green, and blue have respectively. The clock signal GCK has a period obtained by dividing the time width of one scanning period by 64. After a frequency dividing circuit 4 is reset with a latch signal CL1 first, the clock signal GCK is inputted to the frequency dividing circuit 4, whose frequency division output is supplied to a decoder circuit 5. Outputs N1-N64 of the decoder circuit 5 are inputted to the gradation control clock signal generating circuit 1 for red and the gradation control clock signal is outputted according to the settings of SW1-SW15 of an external input means. The signals are similarly set for green and blue.