| 摘要 |
PROBLEM TO BE SOLVED: To attain high speed scanning and miniaturization by providing a lighting circuit to supply a tube current higher than a rated current to each fluorescent light and a control circuit controlling the lighting time of each fluorescent light and reading of a CCD to the color image reader. SOLUTION: This reader is provided with a glass 12 with an original 11 placed thereon to an upper side of a cabinet, and an optical unit 18 consisting of a CCD 183 converts a light reflected in an original 11 receiving a light from a light source 17 consisting of three fluorescent lights 171-173 each emitting lights of R, G, B wavelength into an electric signal. The lighting of the light source 17 is controlled by a lighting circuit 15. Through this constitution, a tube current in excess of the rated current is adopted to quicken a scanning time for color image reading. Then a period of TOFF is provided to the entire period to set an average tube current lower than the rated current so as to warrant the service life of each fluorescent light. |
