| 摘要 |
<p>PURPOSE:To integrate an input device and an output device in one body, to scale down an integrated device and to input directly coordinates by providing a photodetecting means for detecting the presence or absence and the shape of an object brought into contact with a display screen in the vicinity of the light emitting point on the display screen of a light-emitting type graphic display device. CONSTITUTION:When X and Y coordinates are specified by X and Y coordinate signals to set a display on signal to a logic '1', a light emitting diode 2 specified by said coordinates lights up. Simultaneously a phototransistor 3 corresponding to the X and Y coordinates is selected, and its response is outputted to a detection output signal. In order to discriminate whether said response is caused by exogenous light or by the fact that the rays of light of the diode are reflected by a paper or finger, an exogenous light removing circuit checks whether or not the detection output signal is changed by interlocking with the display on signal. If the interlocking is found, said response is caused by reflected light, and the discrimination is made that the book blank of the graphic or the object such as a finger lies in the place specified by coordinates. These detection signals are transmitted to a host computer and are considered to be shape data on the graphic.</p> |
