Image forming apparatus and non-transitory computer readable medium

1. An image forming apparatus comprising:

an image forming device configured to form an image on a sheet using a rotating body under a predetermined image forming condition;

at least one processor configured to implement:

a corrector configured to correct the image forming condition to adjust image density unevenness corresponding to a rotation cycle of the rotating body; and

a controller configured to control the image forming device to form on at least one sheet (i) a plurality of test images that are different in correction amount for the image forming condition and (ii) pointing images indicating intervals corresponding to the rotation cycle of the rotating body, in a state where the rotating body is continuously rotated,

wherein the controller is configured to determine the intervals corresponding to the rotation cycle of the rotating body using a signal related to a gap between the rotating body and another body.

2. The image forming apparatus according to claim 1 , wherein the controller is configured to obtain the rotation cycle of the rotating body using a signal corresponding to a surface shape of the rotating body.

3. The image forming apparatus according to claim 2 , wherein the another body is an image carrier,

wherein the rotating body is a developing body configured to develop an electrostatic latent image carried by the image carrier, and

wherein the controller is configured to obtain the rotation cycle of the developing body using the signal related to the gap between the developing body and the image carrier.

4. The image forming apparatus according to claim 3 , wherein the corrector is configured to correct a magnitude of a voltage to be applied to the developing body, and

wherein the controller is configured to obtain the rotation cycle of the developing body using an alternating current that flows between the developing body and the image carrier in accordance with the voltage applied to the developing body.

5. The image forming apparatus according to claim 1 , wherein the controller is configured to control the image forming device to form the plurality of test images which are different in correction amount, on a plurality of different sheets.

6. The image forming apparatus according to claim 1 , wherein the controller is configured to control the image forming device to form at least one of the pointing images in each of the test images which are different in correction amount.

7. The image forming apparatus according to claim 6 , wherein the controller is configured to control the image forming device to form the pointing images in the test images so as to overlap.

8. The image forming apparatus according to claim 1 , wherein the rotating body is a developing body, and

wherein the another body is an image carrier.

9. The image forming apparatus according to claim 1 , wherein the signal is related to an alternating current flowing between the rotating body and the another body.

10. A non-transitory computer readable medium storing a program that, if executed, causes a computer to execute image formation processing, the image forming processing comprising:

determining a correction amount for an image forming condition to adjust image density unevenness corresponding to a rotation cycle of a rotating body, an image forming device being configured to form an image using the rotating body under the image forming condition;

controlling the image forming device to form on at least one sheet (i) a plurality of test images that are different in correction amount for the image forming condition and (ii) pointing images indicating intervals corresponding to the rotation cycle of the rotating body, in a state where the rotating body is continuously rotated; and

determining the intervals corresponding to the rotation cycle of the rotating body using a signal related to a gap between the rotating body and another body.

11. An image forming apparatus comprising:

an image forming means for forming an image on a sheet using a rotating body under a predetermined image forming condition;

a correction means for correcting the image forming condition to adjust image density unevenness corresponding to a rotation cycle of the rotating body; and

a control means for controlling the image forming means to form on at least one sheet (i) a plurality of test images that are different in correction amount for the image forming condition and (ii) pointing images indicating intervals corresponding to the rotation cycle of the rotating body, in a state where the rotating body is continuously rotated,

wherein the control means determines the intervals corresponding to the rotation cycle of the rotating body using a signal related to a gap between the rotating body and another body.

12. An image forming apparatus comprising:

at least one processor configured to implement:

a corrector configured to correct image density unevenness corresponding to a rotation cycle of a rotating body of an image forming device; and

a controller configured to control the image forming device to form on at least one sheet (i) a plurality of test images that are different in correction amount and (ii) pointing images indicating intervals corresponding to the rotation cycle of the rotating body when the rotating body is continuously rotated,

wherein the controller is configured to determine the intervals corresponding to the rotation cycle of the rotating body using a signal related to a gap between the rotating body and another body.