| 摘要 |
PURPOSE:To display the presence of one picture element through scanning of one frame period and detect the position of a light pen with high accuracy by changing over the luminance of the area corresponding to the visual field of the light pen to a specific color of high luminance in a cathode-ray tube display device. CONSTITUTION:In an initial state, an address counter 5 successively counts clock pulses CP, successively counts the signal Xq increaseing at every one horizontal scanning period and horizontal synchronizing signals HD and outputs the signal Z (Xq,Tq) indicating the coordinate position of each picture element with these and the signals Yq increasing successively at every one vertical scanning period as one set. At this time, if a light pen 1 is applied in the arbitrary picture element position of a cathode-ray tube 2, a light pen output analog signal WPA is obtained at the timing when the sacnning beam passes the inside of the visual field of the light pen and a window signal generator 6 is driven by way of a comparator 3, whereby a window signal W is generated, and the scanning signal of high luminance is emitted to provide the signal WPA of high accuracy and high level. At the timing thereof, a pulse TP is obtained, and this latches the output of the counter 5, whereby the light pen position detection signal is obtained. |
