Canon Kabushiki Kaisha

Kazutaka Yaguchi

Takuya Mukaibara

Hiroshi Kita

Kazushi Ino

Junya Azami

Yusuke Saito

Hidetoshi Hanamoto

Takuya Mukaihara

An apparatus can obtain an amount of color misregistration based on a plurality of test images. Among these test images, the first test image has one line segment of a first color and another line segment of the first color. The second test image has one line segment of the first color and another line segment of a second color or has one line segment of the second color and another line segment of the first color. The third test image has one line segment of the second color and another line segment of the second color. The fourth test image has one line segment of the second color and another line segment of a third color or has one line segment of the third color and another line segment of the second color. The fifth test image has one line segment of the third color and another line segment of the third color.

Image forming apparatus that generates test image group having plurality of test images

A housing includes a first opening and a second opening, and encloses a light-emitting element and a first light receiving unit. The first opening is provided in a first light guide path, and is arranged so that light output from the light-emitting element travels toward a target surface. The second opening is provided in a second light guide path arranged between the target surface and the first light receiving unit. The first opening is an exit opening of a through-hole provided penetrating through the housing, and a shape of the through-hole is a shape in which diffracted light of the +1st order and higher orders and diffracted light of the &#x2212;1st order and higher orders produced at the target surface to be irradiated are not incident on the first light receiving unit.

Structure of optical sensor having light-emitting element and light-receiving element

A housing includes a first opening and a second opening, and encloses a light-emitting element, a first light receiving unit, and a second light receiving unit. The first opening is provided in a first light guide path arranged between the light-emitting element and a first irradiated region of the target surface, and is arranged so that light output from the light-emitting element travels toward the first irradiated region. The second opening is provided in a second light guide path arranged between the first irradiated region and the first light receiving unit, and is arranged so that diffused reflection light from the toner image passes through when the toner image passes the first irradiated region.

Structure of optical sensor having light-emitting element and plurality of light-receiving elements

An image forming apparatus includes a detecting unit configured to detect a test image formed on an image carrier; and an obtaining unit configured to obtain a color misregistration amount using a detection result of the test image by the detecting unit. The test image includes one or more basic patterns; each one of the one or more basic patterns includes a first pattern group and a second pattern group disposed at different positions with respect to a conveyance direction of the image carrier; the first pattern group and the second pattern group each include a plurality of V-shaped patterns; and the V-shaped patterns of the first pattern group and the second pattern group have an axisymmetrical shape about an axis corresponding to a width direction orthogonal to the conveyance direction.

Image forming apparatus that obtains color misregistration amount using detection result of test image

In an image forming apparatus, a control unit performs a control for determining a surface potential A to determine a first voltage to be applied to a charge roller by a charge voltage application circuit so that a surface potential of a photosensitive drum becomes a first potential. The charge voltage application circuit thereafter applies the first voltage to the charge roller to charge the photosensitive drum. In such a state, the control unit performs a second control to determine a light amount of a laser light source, so that the surface potential of the photosensitive drum becomes a second potential. In such a manner, a potential of a photosensitive drum surface is detected with high accuracy. Moreover, a time taken to detect the potential of the photosensitive drum surface is shortened.

Image forming apparatus

The image bearing member includes an image bearing member, a charge unit that charges the image bearing member, an exposure unit that exposes the image bearing member by emitting light thereto, a transfer unit that transfers an image formed on the image bearing member, a detection unit that detects a current flowing between the transfer unit and the image bearing member when a voltage is applied to the transfer unit, and a control unit that causes the charge unit to charge the image bearing member through application of a DC voltage, and calculates a surface potential of the image bearing member based on a detection result of the current when the voltage is applied to the transfer unit, after a light whose light amount is higher than a light amount of a light emitted to the image bearing member from the exposure unit is emitted to the image bearing member.

Image forming apparatus potential surface detector

An object is to accurately determine a factor that drops the quantity of laser light. An image forming apparatus is provided, which has: a laser diode that includes a front side emission point to which drive current is supplied and from which rear light is emitted; a photosensitive drum to which the rear light is emitted; a detection portion that detects a value on a surface potential of the photosensitive drum; and a determination portion that determines an abnormality of the laser diode, and the detection portion detects, a plurality of times, a value on the surface potential of a portion of the photosensitive drum to which the rear light is emitted, and the determination portion determines whether the laser diode is abnormal based on a change amount of the value on the surface potential detected by the detection portion.

Image forming apparatus with malfunction detection

An image forming apparatus includes: a charging member; a transfer member; a setting portion for setting a positive-side discharge start voltage when a positive-side voltage relative to a reference potential is applied to the transfer member after a voltage is applied to the charging member so that a surface of the image bearing member is charged to the reference potential by the charging member and for setting a negative-side discharge start voltage when a negative-side voltage relative to the reference potential is applied to the transfer member after the voltage is applied; a calculating portion for calculating a correction amount for correcting a light portion surface potential, of the image bearing member, calculated by the calculating portion on the basis of the positive-side and negative-side discharge start voltages; and a correcting portion for correcting the light portion surface potential by using the correction amount.

Image forming apparatus including calculating portion configured to calculate surface potential of image bearing member

An image forming apparatus includes an image bearing member, a process member that acts on the image bearing member, a voltage application unit that applies a voltage to the process member, a current detection unit that detects an electric current that flows to the image bearing member, and a control unit that causes the voltage application unit to apply voltages respectively having positive and negative polarities to the process member, to determine a surface potential of the image bearing member based on a detection result acquired by the current detection unit, and to output information about a usage amount of the image bearing member according to the determined result.

Growing community of inventors

Suntou-gun, Japan

Kazutaka Yaguchi