| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical touch panel device, of which the accuracy for detecting the presence/absence of an object will not deteriorate, even if an infrared-emitting element is degraded with the passage of time. <P>SOLUTION: A processing part 13 reads as appropriate a temperature detection signal outputted from a temperature sensor 25. With an LCD 15 and a back light 17 running, an infrared LED 21 is turned off once. An output signal from a PD 23 is read as the amount of light received of external infrared light. The read data are written into a flash memory 19 and are stored. The infrared LED 21 is turned on, and soon after that, the output signal from the PD 23 is read. From this output signal, the amount of light received of the external infrared light, which is read from the flash memory 19, is subtracted; and a decision is made whether it is appropriate to treat the subtracted value as the amount of light received of the infrared light, which has been reflected with the object and has entered the PD 23. <P>COPYRIGHT: (C)2004,JPO</p> |
