| 摘要 |
<p>PURPOSE: To shorten a coordinate detection time by dividing a frame into a display and Y coordinate detection mode and an X coordinate detection mode, and changing the kind of coordinate detection pulses for the X-coordinate detection mode by X electrodes. CONSTITUTION: Column circuits 102-1 and 102-2 supply voltages to the X electrodes of a liquid crystal panel 101 and a common circuit 103 supplies a voltage to the Y electrodes. Then the common circuit 103 selects the Y electrodes in order in synchronism with a latch clock 122 after a first-line marker(FLM) signal 125 indicating the delimitation of a frame becomes high, and then outputs a scanning voltages to them. A voltage corresponding to display data is applied from the column circuit 102 to the X electrodes on the selected Y electrodes and when the voltages are applied to both the X and Y electrodes, the pixels of the display enters a display state. Here, the pulse width of the waveform of the column circuit 102-2 is made double as long as the pulse width of the column circuit 102-1 to recognize which area a pen 105 is positioned in.</p> |
