Patent ID: 6734875
Filing Date: 2004-05-11
Classification: G09G

Abstract:
A full-color LED display system comprising:a screen module for displaying a multicolor image on a screen in which a multitude of first-color LEDs, second-color LEDs and third-color LEDs are orderly arrayed; and a data-sending module which is connected with the screen module via data-sending means, and which gives a control signal as well as image data, the image data being an assembly of gradation data for each colors of each pixels on the screen; on the screen module, there are installed: first-color gradation-control circuits, second-color gradation-control circuits and third-color gradation-control circuits respectively for each pixel on the screen for pulse-lighting the LEDs; data-transferring shift registers for giving the gradation data to the respective first-color gradation-control circuits, second-color gradation-control circuits and third-color gradation-control circuits; and one or a plurality of data-distributing circuits for distributing the gradation data given from the data-sending module to the data-transferring shift registers; the first-color gradation-control circuit, the second-color gradation-control circuit and the third-color gradation-control circuit comprise: an n-bit counter for counting high-speed pulse trains given from the data-sending module; a register for latching the gradation data given from the data-transferring shift register; a digital comparator for comparing magnitude between an n-bit count value from the n-bit counter and the gradation data latched to the register; and a constant-current driver for turning ON and OFF a current-passing to the LED according to a binary output or the digital comparator; the data-sending module comprises: a frame memory for temporarily storing image data to be displayed by the screen module; means for reading out the image data from the frame memory, and successively sending, to the screen module, the image data in a predetermined pixel order; first-color high-speed pulse-train generating means, second-color high-speed pulse-train generating means, and third-color high-speed pulse-train generating means for generating high-speed pulse trains to be given to the respective first-color gradation-control circuit, second-color gradation-control circuit and third-color gradation-control circuit; and means for sending, towards the screen module, the respective high-speed pulse trains for the respective first color, second color and third color; in the screen module, the gradation data for each colors of each pixels successively given from the data-sending module is respectively fed to the register in the gradation-control circuit for the corresponding color in the corresponding pixel via the data-transferring shift register and the data-distributing circuit; and the first-color high-speed pulse trains, the second-color high-speed pulse trains and the third-color high-speed pulse trains, given from the data-sending module, are respectively fed as a count input to the n-bit counter in the gradation-control circuit of the corresponding color; and the high-speed pulse-train generating means for the first color, the second color and the third color in the data-sending module repetitively generate, with a constant period, high-speed pulse trains of 2n pieces or a number closely therebelow, of which pulse intervals vary with time according to a varying characteristic having been set; and comprise: a waveform memory storing digital data in which the pulse trains are expressed as a static binary waveform pattern; and memory-data-reading means for repetitively generating, with a constant period, the high-speed pulse trains by read-accessing the waveform memory at a predetermined speed and in a predetermined order, and outputting, in series, the digital data of the binary waveform pattern.