| 摘要 |
<p>PURPOSE:To input information by instructing a specified point on a screen without contact to the screen of a CRT. CONSTITUTION:An input beam 2 is emitted from a CRT screen 1, passed through a lens part 31 and converted to an electric signal by a photoelectric conversion part 32. A signal processing part 33 extracts the part of the CRT screen 1 brighter than the surrounding from the relevant electric signal, calculates an instructed coordinate on the CRT screen 1 according to how much the part of the screen 1 is vertically and horizontally deviated to the center of the detecting area of the photoelectric conversion part 32, and outputs the coordinate as a coordinate signal 4.</p> |
