| 摘要 |
PROBLEM TO BE SOLVED: To prevent color slurrings caused in reading of an image in a subscanning direction due to the difference in the afterglow characteristic of each color when the luminous quantity of a white light source for emitting a light to an original is controlled by reducing the centroidal movement of read positions of each color in the subscanning direction caused, depending on the afterglow characteristic of the white light source. SOLUTION: This image reader is provided with a centroidal movement reducing means that reduces the centroidal movement of read positions of each color in the subscanning direction generated, depending on the afterglow characteristic of a white light source. The centroidal movement reducing means controls the light emission quantity based on data that are sampled for plural number of times. In this case, the centroidal movement reducing means conducts control so that the temporal center of a light control section coincides with the center of Hsync by a control signal. Thus, the afterglow amount is shared to a front side and a rear side in a light emission region and then averaged to make the centroidal movement due to the afterglow characteristic very small. A circuit 18 of the reader delays the output of a circuit 16 for an arbitrary time, based on a setting value from a CPU 17 (so that the light emitting region comes to the center of the Hsync).
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