| 摘要 |
PROBLEM TO BE SOLVED: To provide a control method of an image scanner provided with a cold cathode tube lamp as a light source capable of properly reducing a rising time of the cold cathode tube lamp and surely improving an image read in an actual image reading operation in response to ambient temperature around the light source. SOLUTION: An initial voltage higher than the rated voltage is applied to the cold cathode tube lamp to raise the cold cathode tube lamp, a photosensor for image reading sequentially senses the luminous quantity in a rising state of the cold cathode tube lamp by each reference time, after a rate of a luminous quantity change by each reference time reaches a reference value or below on the basis of a result of the sensing, the gain and the white color reference are adjusted to apply analog / digital conversion to an image signal, and thereafter the initial voltage is switched into the rated voltage so that the image reading apparatus is brought into a state wherein the image reading apparatus can carry out image reading, and the reference time is set shorter as the ambient temperature around the light source is higher. COPYRIGHT: (C)2005,JPO&NCIPI
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