| 摘要 |
<p>PURPOSE:To simplify the structure of a passive digital tablet by forming the tablet of an array of patterns on an M plane including coordinate. information, partially reading out a pattern at a position specified with a stylus pen, and finding the two-dimensional coordinates of the position commanded on the basis of the read pattern image. CONSTITUTION:A pattern drawn on the top surface 18a of the tablet 18 utilizes a two-dimensional series called the M plane. When the top surface of the tablet 18 is specified with the stylus pen 1 and a side switch 11 is turned ON, an oscillator 8 oscillates and the output of the oscillator is modulated on the basis of an image pattern represented with part of a pattern corresponding to the specified position projected on the photodetection surface 17 of a photodetecting element 9. AN electromagnetic wave radiated by a transmitting coil 3 through the oscillation is received by a receiving coil 25 and inputted to a demodulator 26. The demodulator 26 extracts the image pattern and a coordinate information extracting means 27 extracts coordinate information from a signal representing the image pattern.</p> |
