| 摘要 |
PURPOSE:To dissolve not only the distortion of a read picture but also the variance of density of the read picture by correcting data, which is read by a line sensor, in accordance with the pulse width of read pulses. CONSTITUTION:The timing at which a CCD sensor 4 reads an original 7 is different from a conventional timing and is determined by a read pulse Pr obtained by dividing the frequency of an output pulse Pe of a pulse encoder 11. Since one read pulse Pr is generated each time when a subscanning motor 3 is driven by a certain extent, the line pitch is fixed independently of the variance of feed of a subscanning system, and distortion is not generated in the read picture. Read data D is sent from a CCD driving circuit 5 to a correcting means 15 for every read pulse Pr. A pulse width tp of the read pulse Pr is measured by a timer 17 and is compared with a time signal outputted from a reference timer 16, and the level of read data is corrected to be reduced or raised in accordance with the comparison result by a correcting circuit 18. Thus, the density of the output picture obtained through the correcting circuit 18 is uniform.
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