A toner density sensor includes: a light emitting element configured to radiate light; a light receiving element configured to receive the light emitted from the light emitting element and reflected from a detection object; a substrate whereon the light emitting element and the light receiving element are surface mounted; a case covering the light emitting element and the light receiving element; an optical path configured parallel to the substrate for light generated from the light emitting element; a groove provided in the substrate from the end part of the substrate in the direction light travels from the light emitting element to between the light emitting element and the light receiving element, the groove recessed from the mounting surface in the thickness direction of the substrate; and an insert provided to the case and configured for insertion into the groove.

A toner detection unit is configured by an LED that irradiates light toward an intermediate transfer belt, first and second light receiving elements that respectively receive specular reflection light and diffused reflection light of light irradiated toward the intermediate transfer belt from the LED, a circuit board, and a housing. The LED and the light receiving elements are mounted in a line on the circuit board. The housing is configured to guide, to the first light receiving element, the specular reflection light from a first region within an irradiation region on which light is irradiated from the LED on the intermediate transfer belt, and to guide, to the second light receiving element, the diffused reflection light from a second region which is different from the first region within the irradiation region.

An image forming apparatus including: a toner image forming unit forming a toner image on an intermediate transfer member; a transfer member transferring the toner image on the intermediate transfer member to a recording material in a transfer portion; a driving source applying driving force to the transfer member independently of an intermediate transfer member driving source; an execution unit correcting image misalignment on the basis of a detection result of a test toner image on the intermediate transfer member when no toner image exists in the transfer portion; a container storing the recording material; and an input unit associating the container with a group related to basic weight and surface properties of the recording material. The apparatus includes a driving unit driving the driving source at a speed corresponding to the group if the recording material stored in the container associated with the group is used for image formation.

An image forming apparatus includes a photoconductor, an optical scanner, a development device, a movable density sensor, a density sensor driver, and a processor. The optical scanner includes a light source to emit light, and irradiates a surface of the photoconductor in a main scanning direction with the light to form a latent image on the surface of the photoconductor. The development device develops the latent image into a toner image. The density sensor detects unevenness in density of the toner image in the main scanning direction. The density sensor driver moves the density sensor in the main scanning direction. The processor corrects a driving signal for the light source according to image data to reduce the unevenness in density in the main scanning direction, according to positional data of the density sensor in the main scanning direction and an output value of the density sensor.

An image formation system includes an image forming section that includes a belt and a roller. The image forming section forms, in a predetermined region of a sheet, either: a first patch image for performing tone correction of a toner image formed on the sheet, or a second patch image for monitoring color variation of the toner image formed on the sheet. The image forming system further includes a controller that controls the image forming section to form only one of the first patch image and the second patch image on any one sheet.

An image forming apparatus includes: an image forming unit including a rotating member; a rotation position detecting unit that detects a rotation position of the rotating member; an image density detecting unit that detects density of an image; an image information analysis unit that analyzes image information; a density profile management unit that manages a density profile; a correction data generation unit that generates correction data; a density correction unit that performs density correction; and a density correction control unit that sets a density correction level, wherein when the density correction level is set at reference accuracy, the density correction unit corrects density, and when the density correction level is set at accuracy higher than the reference accuracy, the density profile management unit forms a corrective patch image and generates a new density profile, the correction data generation unit updates the correction data, and the density correction unit corrects density.

An image forming apparatus includes: a correction unit correcting image data based on a correction condition; an image forming unit forming an image based on the corrected image data; a transfer unit transferring the image onto a sheet; a measuring unit measuring a measuring image on an image bearing member; a converting unit converting a measurement result of the measuring image, based on a conversion condition; a first generating unit generating the correction condition based on the converted measurement result; an acquiring unit acquiring a measurement result of a test image formed on the image bearing member; a controller forming a test image on the sheet; a receiving unit receiving instruction from a user comparison of a sample image and the test image transferred on the sheet; and a second generating unit generating the conversion condition, based on the instruction and the acquired measurement result of the test image.

An image forming apparatus includes an image bearing member, a transfer roller, a power feeding rotary member, and a controller. The controller is configured to execute the cleaning mode such that a period in which the cleaning mode is executed comprises a first application period during which a reverse polarity bias having a polarity reverse to that of the transfer bias is continuously applied to the power feeding rotary member, and a second application period during which a same polarity bias having a same polarity with that of the transfer bias is continuously applied to the power feeding rotary member.

An image forming apparatus includes an image bearer, an intermediate transferor, a secondary transferor, a plurality of rotators including a secondary driving rotator, and a detector. The image bearer bears a detection image. The detection image is transferred from the image bearer to the intermediate transferor at a primary transfer position. The secondary transferor is looped around the plurality of rotators and disposed in contact with the intermediate transferor at a secondary transfer position where the detection image is transferred from the intermediate transferor to the secondary transferor. The secondary driving rotator drives the secondary transferor. The detector detects the detection image on the secondary transferor at a detection position. With this configuration, a distance from the secondary transfer position to the detection position on the secondary transferor is an integral multiple of a circumference of the secondary driving rotator.

To prevent the detection accuracy from deteriorating due to stray light, an optical apparatus includes the following configuration. The optical apparatus includes a light-emitting member, a light-receiving member, and a substrate on which the light-emitting member and the light-receiving member are mounted. The substrate includes a plate-like substrate layer and a plate-like conductive layer. The optical apparatus further includes a light-shielding member disposed between the light-receiving member and the light-emitting member and inserted in a through-hole of the substrate provided between the light-receiving member and the light-emitting member. The light-receiving member receives reflected light from a portion to be irradiated with the light emitted from the light-emitting member. The conductive layer is excellent in light-shielding property compared to the substrate layer. The conductive layer is exposed to an inner cylindrical surface of the through-hole.