Patent ID: 7576764

Claim:
An optical writing device, comprising: an exposure device configured to irradiate a light beam and scan the light beam in a main scanning direction to form an image in an image forming area, the exposure device comprising: a first detector provided outside of the image forming area and configured to output a first synchronization detection signal when the light beam enters the first detector; and a writing controller configured to output an image forming start signal for instructing the exposure device to start image formation in the image forming area by modulating the light beam, the writing controller comprising: a counter configured to count a time period in the main scanning direction in synchronization with a reference clock signal to generate a counter value, initialize the counter value when the first synchronization detection signal is detected by the writing controller, and cause the writing controller to output the image forming start signal when the counter value becomes equal to or greater than a reference counter value; and a storage device configured to store a plurality of reference counter values in a corresponding manner with a plurality of operation modes of the optical writing device, wherein the reference counter value is selected from the plurality of reference counter values, wherein the timing for the image forming start signal is based on a difference in an image forming start position between a default operation mode and a second operation mode.