Canon Kabushiki Kaisha

Masayuki Hirano

Masaaki Moriya

Koichiro Ino

An image forming apparatus includes an optical sensor configured to measure reflected light from a test image on the image carrier. The optical sensor includes a printed circuit board, with a light-emitting element provided on a first surface of the printed circuit board, and with the light-emitting element being configured to irradiate the test image on the image carrier with light. The optical sensor also includes a light-receiving element provided on the first surface of the printed circuit board, with the light-receiving element being configured to receive the reflected light from the test image on the image carrier. A connector is provided on a second surface of the printed circuit board opposite to the first surface of the printed circuit board, with a cable for controlling the optical sensor being connected to the connector. A support member is configured to support the optical sensor so that the first surface of the printed circuit board faces a surface of the image carrier, and a controller is configured to control the image forming unit based on a result of the reflected light from the test image measured by the optical sensor. A direction in which the cable is inserted into the connector is orthogonal to the second surface of the printed circuit board.

Technique for attaching optical sensor to image forming apparatus

A printed circuit board has a first mounting surface and a second mounting surface. A light-emitting element and a light-receiving element are mounted on the first mounting surface. An electronic component for driving the light-emitting element is mounted on the second mounting surface. A supporting member supports the printed circuit board. The supporting member has a through-hole in which the electronic component is inserted when the printed circuit board is supported by the supporting member.

An image forming apparatus includes a plurality of image forming units configured to form images of different colors on a transfer member, a comparator configured to compare values of color patterns measured by a sensor with a threshold, and a controller configured to determine whether the threshold corresponds to a target threshold for a current color pattern among the color patterns while the color patterns are measured by the sensor, detect color misregistration concerning the color patterns based on a comparison result of the comparator, and control relative positions of images of the different colors to be formed by the plurality of image forming units, based on the color misregistration.

Image forming apparatus

An image forming apparatus has a light scanning apparatus which is capable of aligning a lens with a plurality of light-emitting devices and forming a high-quality image while suppressing generation of moir&#xe9;. In a first image formation mode, light-emitting devices outputting light beams exposing both ends of the photosensitive member in a rotational direction and at least a part of light-emitting devices exposing an area between exposure positions of the light-emitting devices outputting the light beams exposing the both ends are used to form an electrostatic latent image on the photosensitive member. In a second image formation mode, the light-emitting devices outputting the light beams exposing both ends are not used, and at least a part of light-emitting devices exposing an area between exposure positions of the light-emitting devices outputting the light beams exposing both ends are used to form the electrostatic latent image on the photosensitive member.

Image forming apparatus having light scanning apparatus, and including a plurality of image formation modes

Density unevenness is suppressed even in an image that is formed by a multiple exposures method in which the same region on a photoreceptor is exposed multiple times with different laser light sources (light emitting elements), by adjusting the amounts of light of the respective lasers based on a density difference among test images. An image is formed for each group of light emitting elements grouped together for multiple exposures by dividing, in the main scanning direction, the region of a test image formed on a recording medium. The images formed for the respective multiple-exposure light emitting element groups are compared to one another in density, to thereby adjust the amounts of light of the respective laser light sources (light emitting elements) and reduce fluctuations in image density.

Image forming apparatus and test image forming method

A storage stores data of charging electric potentials at two or more points on a surface of an image carrier, and coordinates thereof expressed using a main-scanning position and a sub-scanning position thereof. A determination unit determines a correction value of a light power from the data of charging electric potentials at two or more points and coordinates thereof that have been read out from the storage unit. The correction value is applied to the light source so as to reduce the charging electric potential or the charging electric potential unevenness of coordinates on the surface of the image carrier. A correction unit uses the determined charging electric potential or correction value to correct the light power of the light source so as to mitigate an influence of charging unevenness at each set of coordinates.

Image forming apparatus and control method thereof

A first mark and a second mark are provided on a photosensitive drum and a rotation reference position sensor detects these marks. A counter is reset according to a detection signal corresponding to the first mark, and is incremented its count value according to a detection signal corresponding to the second mark. A CPU controls an exposure intensity based on light amount correction data read from a memory according to the counted value.

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Matsudo, Japan

Masayuki Hirano