Patent ID: 9651890
Date: 2017-05-16
CPC Classifications: B41J,G03G,G06K,H04N

Claim:
1. An exposing device comprising: an exposing unit having a plurality of light emitters arranged in a main scanning direction, the exposing unit being configured to form a scanning line by exposing an image surface in the main scanning direction, and to form a plurality of pixels arrayed in the main scanning direction by sequentially forming a particular number of scanning lines shifted in a sub-scanning direction, each of the particular number of scanning lines having a plurality of spots arranged in the main scanning direction, each of the plurality of pixels being formed by the particular number of spots arranged in the sub-scanning direction; a clock generator configured to generate frequency-spread clocks having frequency that is spread with a particular modulation cycle; and a driver configured to drive each of the plurality of light emitters of the exposing unit to emit light during a lighting period based on the frequency-spread clocks to form one spot, the driver being configured to set an interval of exposure start time of the particular number of scanning lines, wherein at least one interval of exposure start time is different from a reference period that is obtained by dividing a period for forming the plurality of pixels arrayed in the main scanning direction by the particular number; and wherein the particular number of scanning lines exists within a range in the sub-scanning direction of one pixel array, the particular number of scanning lines having a relationship such that modulated waveforms of the particular number of scanning lines compensate each other, the modulated waveforms being formed with the particular modulation cycle.