JPS54161839A - Picture generating device - Google Patents

Abstract

PURPOSE:To realize display for the overlapped patterns without increasing the number of data by gating the lower-priority pattern via the upper-priority pattern in case the priority is given to the patterns and more than two patterns are overlapped each other. CONSTITUTION:With formation of each parameter of basic patterns (a)-(d) by means of the computer, these parameters are memorized sequentially into memory 3 with those the upper bottoms of which are set upward memorized first. And the horizontal scan lines are counted up to that preceding by one piece the upper bottom of pattern (a), and thus the parameter of (a) is written into register device 6. Then the operation is given every horizontal period to write parameters of patterns (b)-(d). The contents of device 6 are written alternately into memory unit 10 and 11 with every horizontal period and then read out in the adverse timing. Thus, each flip-flop of reading circuit 12 is inverted, and this output is supplied to the logic circuit. And the logic output thus obtained gives gating to the chrominance signals to form the pictures.