| 摘要 |
PROBLEM TO BE SOLVED: To provide a mechanism that arranges pixels at a desired interval by using a scanning lens not having fθ characteristics, and prevents a partial change in magnification due to a change over time and an error in assembly of an optical scanner.SOLUTION: An image forming apparatus according to the present embodiment comprises an imaging lens 406 that irradiates a photoreceptor drum 4 with a laser beam deflected by a deflector 400, the imaging lens 406 not having a constant scanning speed in the main scanning direction of the laser beam at different image heights on the surface of the photoreceptor drum 4, namely, not having fθ characteristics. The image forming apparatus detects the amount of change in scanning speed at an image height different from a reference image height compared with the scanning speed at the reference image height on the surface of the photoreceptor drum 4, and corrects an image signal to be input to a light source according to the detected amount of change in order to control the scanning speed in the main scanning direction of the laser beam to be constant at the different image height.SELECTED DRAWING: Figure 4 |
