Patent ID: 8134586

Claim:
A beam light scanning apparatus comprising: light emitting means for emitting a beam light for scan of an image forming apparatus; distributing means for distributing data based on image information per pixel of a target image in each line in a direction of main scan into two-channel data trains made up of an odd-numbered pixel data train and an even-numbered pixel data train; a first memory provided corresponding to the odd-numbered pixel data train, the first memory allowing reading and writing of the odd-numbered pixel data train; a second memory provided corresponding to the even-numbered pixel data train, the second memory allowing reading and writing of the even-numbered pixel data train; data writing means for writing the odd-numbered pixel data train and the even-numbered pixel data train distributed by the distributing means into the first memory and the second memory, respectively, in parallel in response to a line sync signal; data reading means for reading the odd-numbered pixel data train and the even-numbered pixel data train out of the first memory and the second memory, respectively, in parallel during the same processing cycle corresponding to the line sync signal; combining means for combining the odd-numbered pixel data train and the even-numbered pixel data train read out of the first memory and the second memory, respectively, by the data reading means into a data train in the original order of pixels in each line; and a single Pulse Width Modulator for generating a driving signal with pulse width modulation based on the data train combined by the combining means.