Patent ID: 6043852
Filing Date: 2000-03-28
Classification: H04N

Abstract:
A wipe pattern generating apparatus, comprising:a buffer memory for temporarily storing polar coordinate data of an entire contour of a desired wipe pattern,polar coordinate data forming means for forming polar coordinate data indicating a position of a pixel on a display screen of display means, anda comparator for comparing distance data of the entire contour of the wipe pattern read out from said buffer memory on the basis of angle data outputted from said polar coordinate data forming means and distance data outputted from said polar coordinate data forming means, for forming switching data,wherein the improvement resides in that the wipe pattern generating apparatus further comprisesa graphic memory for storing the polar coordinate data of a portion of the contour of the desired wipe pattern, andan address former for forming readout addresses for said graphic memory and write addresses for said buffer memory on the basis of instruction data generated therein adapted to form the desired wipe pattern comprising multiple copies of said portion of the contour of the desired wine pattern,said buffer memory being adapted for storing the polar coordinate data of the entire contour of the desired wipe pattern formed on the basis of the polar coordinate data of the portion of the contour of the wipe pattern stored in said graphic memory.