| 摘要 |
PROBLEM TO BE SOLVED: To prevent color slurrings produced in reading of an image in a subscanning direction due to the difference of the afterglow characteristic of each color when the luminous quantity of a white light source for emitting light to an original is controlled by reducing the centroidal movement of read positions of each color in the subscanning direction which is 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 caused depending on the afterglow characteristic of a white light source. The centroidal movement reducing means conducts reduction control based on data of a luminous quantity emitted from the while light source and sets the reduction control in the unit of scanning. In this case, the centroidal movement reducing means conducts control, so that the temporal center of a light control section is 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 area 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).
|
