Light pen output controlling system

Abstract

Abstract PURPOSE:To reduce the number of input/output pins, by unifying the transmission route for a switch signal outputted from a light pen and the transmission route for a photodetection signal wherever practicable. CONSTITUTION:A switch signal of output signals of a light pen 1 takes a transmission route reaching a pulse width detecting circuit 15 from the light pen 1 through a voltage comparator 5-1, a waveform shaping circuit 6'-1, an OR gate 14, a driver 7', a common connection cable 12', and a receiver 8'. Meanwhile, a photodetection signal takes a transmission route reaching the pulse width detecting circuit 15 from the light pen 1 through a voltage comparator 5-2, a waveform shaping circuit 6'-2, the OR gate 14, the driver 7', the common connection cable 12', and the receiver 8'. Consequently, since the switch signal and the photodetection signal are transferred to a common output circuit by the OR gate 14 and are processed, the output signal of the driver 7' in the output side of the OR gate 14 has two pulse widths, and the cable is made common.

Inventors

• 👤 Shigeki Sano
• 👤 Eiji Yonemoto
• 👤 Yuji Yoshida
• 👤 Hideo Takada

Bibliographic Details