Image forming apparatus and non-transitory computer readable medium

1. An image forming apparatus comprising:

an image carrier configured to carry a developer image;

an exposure device configured to expose the image carrier;

a developer image forming unit configured to form the developer image by transporting a developer to a latent image formed on the image carrier by exposing the image carrier by the exposure device;

a sensor provided to detect a position change of the developer image forming unit;

a memory; and

a processor configured to

generate correction data for correcting density unevenness in a main scanning direction detected based on an image generated by the developer image formed on the image carrier by the developer image forming unit,

correct the density unevenness in the main scanning direction occurring in the developer image by changing an exposure amount when the image carrier is exposed by the exposure device, using the generated correction data, and

when the position change of the developer image forming unit in the main scanning direction is detected by the sensor, adjust the correction data by a detected position change amount, wherein:

the developer image forming unit comprises a magnetic field generator configured to generate a magnetic field,

the processor is configured to generate the correction data for correcting the density unevenness in the developer image caused by non-uniformity of the magnetic field of the developer image forming unit in the main scanning direction, and

the developer image forming unit is configured by connecting a plurality of magnetic field generators, and the processor generates the correction data for correcting the density unevenness in the developer image caused by the non-uniformity of the magnetic field of the developer image forming unit in the main scanning direction, the non-uniformity of the magnetic field occurring at a connection portion between the plurality of magnetic field generators.

2. The image forming apparatus according to claim 1 , wherein the processor is configured to detect the position change of the developer image forming unit in the main scanning direction at a preset timing.

3. The image forming apparatus according to claim 1 , wherein the processor is configured to detect the position change of the developer image forming unit in the main scanning direction based on an instruction input by a user.

4. The image forming apparatus according to claim 1 , wherein

the processor is configured to

form a developer image corresponding to a shape of the entire developer image forming unit on the image carrier, and

detect the position change of the developer image forming unit in the main scanning direction by detecting a position of an end portion of the developer image formed on the image carrier.

5. The image forming apparatus according to claim 4 , wherein

the processor is configured to

form the developer image corresponding to the shape of the entire developer image forming unit on the image carrier by entirely exposing an area of the image carrier corresponding to an entire area of the developer image forming unit by the exposure device after the image carrier is charged, and

detect the position change of the developer image forming unit in the main scanning direction by detecting the position of the end portion of the developer image formed on the image carrier.

6. The image forming apparatus according to claim 4 , wherein

the processor is configured to

form the developer image corresponding to the shape of the entire developer image forming unit on the image carrier by charging the image carrier such that the image carrier has a voltage after the image carrier is exposed by the exposure device, and

detect the position change of the developer image forming unit in the main scanning direction by detecting the position of the end portion of the developer image formed on the image carrier.

7. A non-transitory computer readable medium storing a program that causes a processor to execute information processing, the information processing comprising:

generating correction data for correcting density unevenness in a main scanning direction detected based on an image generated by a developer image formed on an image carrier by a developer image forming unit by transporting a developer to a latent image formed on the image carrier by exposing the image carrier by a exposure device;

correcting the density unevenness in the main scanning direction occurring in the developer image by changing an exposure amount when the image carrier is exposed by the exposure device, using the generated correction data, and

when a position change of the developer image forming unit in the main scanning direction is detected, adjusting the correction data by a detected position change amount wherein:

the developer image forming unit comprises a magnetic field generator configured to generate a magnetic field,

the information processing further generates the correction data for correcting the density unevenness in the developer image caused by non-uniformity of the magnetic field of the developer image forming unit in the main scanning direction, and

the developer image forming unit is configured by connecting a plurality of magnetic field generators, and the information processing generates the correction data for correcting the density unevenness in the developer image caused by the non-uniformity of the magnetic field of the developer image forming unit in the main scanning direction, the non-uniformity of the magnetic field occurring at a connection portion between the plurality of magnetic field generators.

8. An image forming apparatus comprising:

image carrying means for carrying a developer image;

exposure means for exposing the image carrying means;

developer image forming means for forming the developer image by transporting a developer to a latent image formed on the image carrying means by exposing the image carrying means by the exposure means;

sensor means for detecting a position change of the developer image forming means; and

means for

generating correction data for correcting density unevenness in a main scanning direction detected based on an image generated by the developer image formed on the image carrying means by the developer image forming means,

correcting the density unevenness in the main scanning direction occurring in the developer image by changing an exposure amount when the image carrying means is exposed by the exposure means, using the generated correction data, and

when a position change of the developer image forming means in the main scanning direction is detected by the sensor means, adjusting the correction data by a detected position change amount, wherein:

the developer image forming means comprises a magnetic field generator configured to generate a magnetic field,

the apparatus further comprises a means for generating the correction data for correcting the density unevenness in the developer image caused by non-uniformity of the magnetic field of the developer image forming unit in the main scanning direction, and

the developer image forming means is configured by connecting a plurality of magnetic field generators, and the apparatus further comprises a means for generating the correction data for correcting the density unevenness in the developer image caused by the non-uniformity of the magnetic field of the developer image forming unit in the main scanning direction, the non-uniformity of the magnetic field occurring at a connection portion between the plurality of magnetic field generators.