| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique to realize a function as a tablet by detecting a pressure to a liquid crystal display element. <P>SOLUTION: A detection pulse generating circuit 204 activates gate lines G<SB>1</SB>to G<SB>L</SB>by giving them pulses in the order of lines. While the gate line G<SB>j</SB>is activated, a transistor 402 is turned on by a positive pulse of a reset signal RS, and a capacitor C1 and a liquid crystal C2 of a liquid crystal display cell M<SB>ij</SB>are discharged through a drain line D<SB>i</SB>. When the reset signal RS becomes "L", the transistors 401 and 402 are turned on and off, respectively, and the capacitor C1 and the liquid crystal C2 are charged by a power source Vdd. In the case that the liquid crystal display cell M<SB>ij</SB>of a j-th row is depressed, it is charged with more charge quantity than the other liquid crystal display cells as the capacity of the liquid crystal C2 is increased. An output Vo based on a charging current Ir becomes large therefore, and a judgement signal E<SB>i</SB>is activated by setting a reference potential Vr adequately. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
