Picture forming device

Abstract

Abstract PURPOSE:To obtain a reproduced picture with high quality without deteriorated resolution by applying pulse width modulation to a picture signal with plural modulation means based on plural pattern signals and selecting a modulation signal based on its density gradient and the period of the pattern signal. CONSTITUTION:A clock CLK 117 with a period four times the period of a clock VCLK 120 or over is given from a crystal oscillator 115 to a circuit 111 and an HSYNC signal 119, a VCLK 120 and an SCLK 118 synchronously with the BD signal 116 and the CLK 117 are outputted. The SLK 118 is given to the circuit 112, and pattern clocks CLK 123-125 synchronously with the SLK 118 are given to comparators 104-106. The signals 123-125 are compared with a video signal 121 and a binary-coded signal is given to a select circuit 107, and the result is selected according to a selection signal 122 from an identification circuit 113, and the selected modulation signal (PWM) is given to a laser driver 109 of a recording section 132 and the laser beam is modulated to form a copied picture.

Inventors

• 👤 Kazuhiko Hirooka
• 👤 廣岡　和彦
• 👤 Hitoshi Arai
• 👤 仁 荒井
• 👤 Masaki Sakai
• 👤 坂井　雅紀

Bibliographic Details