| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To keep a proper power saving control operation without requiring setting operation of an operator adjusting a luminance reference value. <P>SOLUTION: In power saving control operation, transition/recovery are performed by detecting the presence/absence of external light. Therefor, an illuminance sensor 23 receiving the external light through a small window 24 of an outer cover 29 is mounted. The illuminance sensor 23 is also used as means for detecting reference light of a prescribed light volume emitted from a light emitter 25. As a detection value when receiving the reference light indicates the degree of deterioration of the sensor, the illumination sensor adjusts a threshold value (a reference value of illuminance determining a transition/recovery condition) set for determining establishment of a prescribed transition/recovery condition based on the reference light detection value and compensates the deterioration of the illuminance sensor. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
