| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a display device with built-in input/output functions which is less subject to interference between a frequency of an ultrasonic wave and a frequency of an inverter. <P>SOLUTION: A pen 4 in touching the face of a liquid crystal panel 21 transmits an infrared ray from an infrared transmitting element 41, and an ultrasonic wave from an ultrasonic wave transmitting element 42. An infrared ray receiving element 31 and ultrasonic wave receiving units 32 and 33 of a receiving unit 3 receive them. A lamp 22b is lighted by an inverter 22c, and a backlight 22 irradiates the liquid crystal panel 21 through a light guide plate 22a. The frequency of the ultrasonic wave and that of the inverter are differentiated. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
