Optical writing device, image forming apparatus, optical writing method, and computer-readable recording medium

An optical writing method performed in an optical writing device that includes a pattern storage unit configured to store therein pieces of dithering information indicating a plurality of dithering patterns whose densities are different, each dithering pattern being made up of a given number of pixels, each piece of dithering information including pieces of identification information associated with the pixels of the corresponding dithering pattern, respectively, and a pixel setting information storage unit configured to store therein pieces of pixel setting information in which pieces of colored/colorless information indicating each of the pixels is colored or colorless are associated with the pieces of identification information, respectively, the pieces of colored/colorless information being set based on a resolution of a light source for forming an electrostatic latent image on a photosensitive element, the optical writing method comprising:

• arranging the same dithering patterns in a way that the dithering patterns form a pattern with a given size, for each of the different dithering patterns stored;
• causing the light source to emit light based on pixel information generated by setting the pixels of each of the same dithering patterns to be colored or colorless in accordance with the pixel setting information, to form electrostatic latent images of a plurality of patterns each in the given size and in a different density;
• acquiring a reading signal corresponding to the density for each of the patterns in the given size and different densities;
• and
• selecting and outputting one of the pieces of dithering information corresponding to a reading signal that indicates a density closest to a predetermined reference density among the reading signals acquired from the patterns in the given size and the different densities.

A non-transitory computer-readable recording medium with an executable program stored thereon for controlling an optical writing device that includes a pattern storage unit configured to store therein pieces of dithering information indicating a plurality of dithering patterns whose densities are different, each dithering pattern being made up of a given number of pixels, each piece of dithering information including pieces of identification information associated with the pixels of the corresponding dithering pattern, respectively, and a pixel setting information storage unit configured to store therein pieces of pixel setting information in which pieces of colored/colorless information indicating each of the pixels is colored or colorless are associated with the pieces of identification information, respectively, the pieces of colored/colorless information being set based on a resolution of a light source for forming an electrostatic latent image on a photosensitive element, wherein the program instructs a processor of the optical writing device to perform:

• arranging the same dithering patterns in a way that the dithering patterns form a pattern with a given size, for each of the different dithering patterns stored;
• causing the light source to emit light based on pixel information generated by setting the pixels of each of the same dithering patterns to be colored or colorless in accordance with the pixel setting information, to form electrostatic latent images of a plurality of patterns each in the given size and in a different density;
• acquiring a reading signal corresponding to the density for each of the patterns in the given size and different densities;
• and
• selecting and outputting one of the pieces of dithering information corresponding to a reading signal that indicates a density closest to a predetermined reference density among the reading signals acquired from the patterns in the given size and the different densities.