Image forming apparatus that stores a cumulative image formation amount
An image forming apparatus comprises a rotationally driven photosensitive body, a charging device that charges a surface of the photosensitive body, an exposure light source that forms an electrostatic latent image by exposing the surface of the photosensitive body to light, a developing device that forms a toner image by developing the electrostatic latent image using toner, a transfer member that transfers the toner image to a sheet, a first memory that stores a cumulative image formation amount for each one of N exposure regions, and a control circuit that controls the exposure light source.
1 . An image forming apparatus comprising:
a rotationally driven photosensitive body;
a charging device that charges a surface of the photosensitive body;
an exposure light source that forms an electrostatic latent image by exposing the surface of the photosensitive body to light;
a developing device that forms a toner image by developing the electrostatic latent image using toner;
a transfer member that transfers the toner image to a sheet;
a first memory that stores a cumulative image formation amount for each one of N exposure regions of the surface of the photosensitive body; and
a control circuit that controls the exposure light source so that an exposure condition is determined on a basis of the cumulative image formation amount for each one of the N exposure regions and each one of the N exposure regions is exposed with light according to the exposure condition.
2 . The image forming apparatus according to claim 1 , wherein
the control circuit determines the exposure condition for each one of the N exposure regions so that an exposure amount increases as the cumulative image formation amount increases.
3 . The image forming apparatus according to claim 1 , wherein
the N exposure regions are arranged in a first direction parallel with a rotary shaft of the photosensitive body.
4 . The image forming apparatus according to claim 1 , wherein
the N exposure regions are arranged in a second direction orthogonal to a first direction parallel with a rotary shaft of the photosensitive body.
5 . The image forming apparatus according to claim 1 , wherein
the N exposure regions are arranged in a matrix pattern on the surface of the photosensitive body.
6 . The image forming apparatus according to claim 1 , further comprising
a sensor that detects an environment condition of an environment where the image forming apparatus is installed,
wherein the control circuit determines the exposure condition for each one of the N exposure regions on a basis of the cumulative image formation amount and the environment condition detected by the sensor.
7 . The image forming apparatus according to claim 6 , further comprising
a second memory that stores a plurality of correction formulas associated in a one-to-one relationship with a plurality of different environment conditions,
wherein the control circuit determines the exposure condition for each one of the N exposure regions by selecting, from among the plurality of correction formulas, a correction formula corresponding to the environment condition detected by the sensor and using the selected correction formula.
8 . The image forming apparatus according to claim 6 , wherein
the environment condition includes at least one of temperature and humidity.
9 . The image forming apparatus according to claim 1 , wherein
the control circuit multiplies the cumulative image formation amount for each one of the N exposure regions and a first correction coefficient to obtain a product, adds a second correction coefficient to the product, and determines an exposure amount for the exposure condition.
10 . The image forming apparatus according to claim 9 , wherein
the first correction coefficient and the second correction coefficient are determined according to a type of the toner.
11 . The image forming apparatus according to claim 9 , wherein
the first correction coefficient and the second correction coefficient are determined according to a type of the photosensitive body.
12 . The image forming apparatus according to claim 9 , wherein
the first correction coefficient and the second correction coefficient are determined according to the N corresponding to a number of the exposure regions.
13 . The image forming apparatus according to claim 9 , further comprising
an input device that accepts input of the first correction coefficient and the second correction coefficient.
14 . An image forming apparatus comprising:
a rotationally driven photosensitive body;
a charging device that charges a surface of the photosensitive body;
an exposure light source that forms an electrostatic latent image by exposing the surface of the photosensitive body to light;
a developing device that forms a toner image by developing the electrostatic latent image using toner;
a transfer member that transfers the toner image to a sheet;
a memory that stores a thickness of a photosensitive layer of N exposure regions of the surface of the photosensitive body or thickness information relating to a reduction amount of the thickness; and
a control circuit that controls the exposure light source so that an exposure condition is determined on a basis of the thickness information for each one of the N exposure regions and each one of the N exposure regions is exposed with light according to the exposure condition.
15 . An image forming apparatus comprising:
a rotationally driven photosensitive body;
a charging device that charges a surface of the photosensitive body;
an exposure light source that forms an electrostatic latent image by exposing the surface of the photosensitive body to light;
a developing device that forms a toner image by developing the electrostatic latent image using toner;
a transfer member that transfers the toner image to a sheet;
a memory that stores a cumulative image formation amount for each one of N exposure regions of the surface of the photosensitive body; and
a control circuit that determines content of image correction on a basis of the cumulative image formation amount for each one of the N exposure regions,
wherein the control circuit corrects image data corresponding to the N exposure regions according to the content of the image correction determined for each one of the N exposure regions.
16 . The image forming apparatus according to claim 15 , wherein
the content of the image correction includes dither processing.
17 . An image forming system comprising:
an image forming apparatus that forms a toner image as a user image prepared by a user and an adhesive toner image as an adhesive; and
a booklet manufacturing apparatus that forms a sheet bundle including layers of sheets discharged from the image forming apparatus, heats the adhesive toner image of the sheet bundle to re-melt the adhesive toner image, and presses the sheet bundle to bond together the sheet bundle and manufacture a booklet,
wherein the image forming apparatus comprises:
a rotationally driven photosensitive body;
a charging device that charges a surface of the photosensitive body;
an exposure light source that forms an electrostatic latent image by exposing the surface of the photosensitive body to light;
a developing device that forms a toner image by developing the electrostatic latent image using toner;
a transfer member that transfers the toner image to a sheet;
a memory that stores a cumulative image formation amount for each one of N exposure regions of the surface of the photosensitive body; and
a control circuit that controls the exposure light source so that an exposure condition is determined on a basis of the cumulative image formation amount for each one of the N exposure regions and each one of the N exposure regions is exposed with light according to the exposure condition.