| 摘要 |
PURPOSE: To keep, more particularly, a lamp and a lighting profile in a predetermined optimal state in improving the operability of a document lighting device. CONSTITUTION: A lighting output from a fluorescent lamp 25 used in an RIS scanner is kept in optimal by monitoring the on/off state of the lamp 25 and turning on the lamp 25 for a certain time after a specified accumulative off time. The lamp 25 is turned on for two minutes after an off time for one hour. After this on time for two minutes, a diagnosis test judging whether or not the fluctuation of lamp output brings an out-of-specification state such as requiring recalibration to a light sensor array 24 is automatically performed. This calibration controls the gain of the light sensor array 24 until the response of the light sensor 24 reaches a nominal percentage range. |
