| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce detection errors caused by sounds emitted from a loudspeaker and the like when human detection is performed with an ultrasonic sensor so as to automatically execute an image persistence reducing function of a display device. <P>SOLUTION: Normal image display is performed by turning off an image persistence reducing flag 206 and resetting a Koff counter which adds up human detection time. Then, when a detection error flag 203 is in an off state and, by comparing the detection value 205 of the ultrasonic sensor 125 with a preset threshold value, if the detection value 205 is kept equal to or higher than the threshold value of the state where a person does not exist for the set time (10 minutes) or longer, the image persistence reducing flag 206 is turned on and the image persistence reducing display is automatically carried out. The display returns from the image persistence reducing display to the normal display when the detection error flag 203 is in the off state, and the detection value 205 is kept lower than the threshold value for the set time (10 seconds) or longer. <P>COPYRIGHT: (C)2009,JPO&INPIT |
