| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a touch panel device capable of exciting a surface acoustic wave at an optimum frequency from an excitation means for reception with a high gain. <P>SOLUTION: In starting the device or at a predetermined time interval during operation of the device, a frequency f<SB>2</SB>giving a reception signal at a maximum level in a reception element 33 is decided by exciting an IDT 36 of an excitation element 32 while a frequency is varied within a range fromΔf below an approximation f<SB>1</SB>of a current driving frequency f toΔf above the approximation f<SB>1</SB>, and afterward, the decided frequency f2 is used as a driving frequency. Since a burst wave is applied at an optimally controlled frequency, the reception can be carried out with a high gain. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
