Patent ID: 8848238

Claim:
An optical writing control device that forms electrostatic latent images on image carriers by controlling light sources exposing the image carriers, the optical writing control device comprising: a pixel information obtaining unit which obtains pixel information about pixels constituting an image which is to be formed and output, from a control unit of an image forming apparatus main body, and stores the pixel information in a storage medium; a light emission control unit which controls light emission of each of the multiple light sources which are provided for respective different colors, on the basis of the obtained information about the pixels, and exposes the multiple image carriers which are provided for the respective different colors; a detection signal obtaining unit which obtains a detection signal of a sensor that detects an image in a conveying path on which the image obtained by developing the electrostatic latent images formed on the image carriers is transferred and conveyed; a detection timing obtaining unit which obtains, on the basis of the obtained detection signal, detection timing of a positional deviation correction pattern used to correct a positional deviation in a sub-scanning direction between the different colors of the image that is formed by developing the electrostatic latent images formed using the multiple image carriers; a positional deviation amount obtaining unit which obtains a positional deviation amount in the sub-scanning direction for each of the different colors, on the basis of a difference between a reference value determined in advance and the detection timing of the positional deviation correction pattern obtained for a corresponding color; and a correction amount calculating unit which calculates a central value of a distribution range of the positional deviation amounts in the sub-scanning direction obtained for the different colors, and calculates a correction amount for each of the different colors on the basis of a difference between the calculated central value and the positional deviation amount in the sub-scanning direction obtained for a corresponding color, wherein the light emission control unit controls light emission of each of the multiple light sources on the basis of the calculated correction amount of each of the different colors, when a correction amount indicates that light emitting timing of a light source is to be delayed, the light emission control unit delays the light emitting timing of the light source by delaying reading timing of the pixel information stored in the storage medium; and when a correction amount indicates that light emitting timing of a light source for a color is to be advanced, the light emission control unit delays timing at which the pixel information about colors other than the color starts to be obtained from the control unit of the image forming apparatus main body, thus relatively advancing the light emitting timing of the light source for the color.