Image forming apparatus

An image forming apparatus comprising:

• an output section that forms an electrostatic latent image onto an image carrier by using light emitted by a light source and outputs an image onto a recording medium by developing the formed electrostatic latent image;
• a first correction unit that creates, on a basis of density variation data input to the first correction unit, a correction table storing correction amounts for correcting periodic density variations due to a rotating body and density variations not due to a rotating body;
• a second correction unit that creates, on a basis of density variation data input to the second correction unit, a sinusoidal set value representing a correction amount for correcting periodic density variations due to a rotating body and a correction table storing a correction amount for correcting density variations not due to a rotating body;
• a memory;
• and
• a processor configured to:
• display a screen that prompts a user as to whether the user selects a first density correction method that gives priority to reducing density unevenness in halftones or a second density correction method that gives priority to reducing density unevenness near the highest density;
• input density variation data created by detecting a halftone test image to the first correction unit and store a created correction table into the memory when the first density correction method is selected;
• retrieve a correction amount corresponding to a rotation phase of a rotating body included in the output section and a correction amount corresponding to a position in a subscanning direction from the correction table and perform correction of a density of an image, which is formed onto a recording medium, when an image is formed in the output section;
• input density variation data created by detecting a test image having a density near the highest density to the first correction unit, store a created correction table into the memory, input density variation data created by detecting a halftone test image to the second correction unit, and store a created correction table and a created sinusoidal set value into the memory when the second density correction method is selected;
• retrieve a correction amount corresponding to a rotation phase of a rotating body included in the output section and a correction amount corresponding to a position in the subscanning direction from the correction table and perform correction of a density of an image, which is formed onto a recording medium, if a pixel value of a pixel to be formed is near the highest density when an image is formed in the output section;
• and
• calculate a correction amount corresponding to a rotation phase of a rotating body included in the output section on a basis of the sinusoidal set value, retrieve a correction amount corresponding to a position in the subscanning direction from the correction table, and perform correction of a density of an image, which is formed onto a recording medium, if a pixel value of a pixel to be formed is in halftones.

An image forming apparatus comprising:

• means for forming an electrostatic latent image onto an image carrier by using light emitted by a light source and outputting an image onto a recording medium by developing the formed electrostatic latent image;
• means for storing a sinusoidal set value representing a correction amount for correcting periodic density variations that occur in an image, which is to be formed, in a subscanning direction and that are caused by a rotating body and a correction table in which correction amounts for correcting density variations that occur in an image, which is to be formed, in the subscanning direction and that are not caused by a rotating body are each stored in association with a corresponding position in the subscanning direction;
• means for calculating a first correction amount corresponding to a rotation phase of a rotating body included in the means for forming the electrostatic latent image on a basis of the sinusoidal set value and retrieving a second correction amount corresponding to a position in the subscanning direction from the correction table when an image is formed in the means for forming the electrostatic latent image;
• and
• means for performing, by using the calculated first correction amount and the retrieved second correction amount, correction of a density of an image that is formed onto a recording medium.