| 摘要 |
<p>PURPOSE:To reduce the number of bits for coding, without deteriorating the quality of manuscript signals, by obtaining a polar coordinate from the difference of signals of X and Y coordinates and predicted values, through a signal displaying the state of a pen on a tablet. CONSTITUTION:The state of a pen on a tablet is detected at a coordination detecting circuit, and signals X1 and Y1 representing X and Y coordinates and a signal Z1 representing if a stylus is contacted on the tablet are applied to an encoder 40. A control signal is applied to differential circuits 42 and 43 inputting signals X1 and X2 from a control circuit 41 inputting the signal Z1 and the X and Y coordinates are outputted according to the control signal with the difference from the respective predicted value. The information of the coordinates X and Y from a coordinate conversion circuit 44 is converted into an angle and a distance through the outputs of the circuits 42 and 43, and the difference value to the angle and distance is obtained from difference circuits 45 and 46 and the signals X1 and Y1 are applied to an inputted multiplexer 47. Thus, the polar coordinate is obtained from the difference signal at the multiplexer 47 to make encoding easy.</p> |
