Canon Kabushiki Kaisha

Kiyoto Toyoizumi

Masaru Shimura

Hideo Nanataki

Shinsuke Kobayashi

Shinji Katagiri

Hideaki Hasegawa

Yasunari Watanabe

Kenichi Iida

Kouji Yasukawa

Kengo Kawamoto

Masahiro Tambo

Kaoru Sato

Junichi Kimizuka

Yasukazu Maeda

Hitoshi Machino

Hideaki Hirasawa

Jun Igarashi

Masamichi Iida

A controller which causes a light emitting element to continuously perform minute emission for a plurality of dots in a level in which toner is not attached to a non-image section on an image bearing member is provided. The controller controls a first driving current for an image section and controls a second driving current used to perform the minute emission by the light emitting element in the non-image section several times in one job. In the image section, a driving current obtained by adding the first driving current to the second driving current is supplied so that the light emitting element emits light.

Color image forming apparatus

A driving unit causes first and second light emitting units each to emit light in a time following a pulse duty with a light amount at a first light emission level for printing on an image portion in an image formable region of a photosensitive member according to input of print data, and causes the first and the second light emitting units each to emit light with a light amount at a second light emission level of weak light emission on a non-image portion in the image formable region of the photosensitive member, and an adjustment unit adjusts each of first, second, third, and fourth driving currents for a plurality of times in one job.

Image forming apparatus and method for adjustment of light amount during weak light emission

In a color image forming apparatus, the amount of light of an exposure unit for a weak exposure is changed according to a remaining service life of a photosensitive drum when the weak exposure is performed for the background area of a corresponding photosensitive drum by using the exposure unit.

A color image forming apparatus has a light emitting element emitting light, a laser driving unit causing the light emitting element to emit light of a light amount at a first emission level for visualizing a toner image onto a first area where the toner image is to be visualized on a charged photosensitive member and to emit light of a light amount at a second emission level for weak emission onto a second area where the toner is not to be adhered to the charged photosensitive member. In addition, an acquiring unit acquires information of an integrated number of rotations of the photosensitive member, a drive current adjusting unit adjusts the drive current for the second emission level, and changes a magnitude of the drive current for the second emission level in accordance with the information of the integrated number of rotations of the photosensitive member.

Color image forming apparatus having drive current adjustment

The image forming apparatus includes a photosensitive drum and a light emitting device. In the rotational axis direction of the photosensitive drum, the width of the weak light exposure region on the photosensitive drum in which an exposing device emits weak light is larger than the width of a region corresponding to the width of a recording medium on which an image is formed, but smaller than the width of a region on the photosensitive drum charged by a charging roller.

Image forming apparatus

A light irradiating device causes a light source to emit light with normal emitted light quantity sufficient for adhering toner on a photosensitive member, on an image portion of the photosensitive member, and causes the light source to emit light with minute emitted light quantity sufficient for preventing toner from being adhered on the photosensitive member, which is smaller than normal emitted light quantity. The light irradiating device includes a determining unit to determine a reference value input to the light irradiating device. Minute emitted light quantity is set based on the reference value input to the light irradiating device. The determining unit determines the reference value to be input to the light irradiating device based on information of relationship between a predetermined reference value and the light quantity in the position of the photosensitive member when causing the light source to emit light, based on the predetermined reference value.

A color image forming apparatus has a plurality of photosensitive members, a light emitting element emitting light, a laser driving unit causing the light emitting element to emit light of a light amount at a first emission level for visualizing the toner image onto a first area where the toner image is to be visualized on the charged photosensitive member and to emit light of a light amount at a second emission level for weak emission onto a second area where the toner is not to be adhered to the charged photosensitive member. In addition, an acquiring unit acquires information associated with a remaining lifetime of each of the photosensitive members, a first drive current adjusting unit adjusts the first drive current, and a second drive current adjusting unit adjusts the second drive current, with the second drive current adjusting unit changing a magnitude of the second drive current in accordance with the information associated with the remaining lifetime of each of the photosensitive members.

To provide high flexibility in the arrangement of optical paths toward a plurality of photosensitive members and not to cause an increase in size of an image forming apparatus even when a cartridge capacity is increased, provided is an image forming apparatus including: light source units; a deflecting unit for deflecting a plurality of light beams for scanning; a plurality of photosensitive members; an imaging optical system for imaging the light beams deflected for scanning; and a plurality of toner containers, in which the toner containers are different in capacity, and an optical path length from the photosensitive member for the same color as the toner container having a large capacity to the deflecting surface of the deflecting unit is longer than an optical path length from the photosensitive member for the same color as the toner container having a small capacity to the deflecting surface of the deflecting unit.

Optical scanning apparatus and color image forming apparatus using the same

A color image forming apparatus specifies print mode (media), forms a test image based on gradation levels of a plurality of colors according to the specified print mode (media), and detects the test image with a color sensor. The color image forming apparatus performs gray axis correction calculation based on detection result obtained by the color sensor.

Color image forming apparatus and color adjustment method

In an image forming apparatus, a plurality of laser beams are emitted by a plurality of laser sources and are scanned onto a recording medium. The laser beams scanned are detected by two light-receiving elements juxtaposed in a main scanning direction. The output signals from the two light-receiving elements are compared so that a reference timing signal indicating that each of the scanned laser beams has reached a substantially middle position between the two light-receiving elements is outputted. The write operations of the plurality of laser sources in the main scanning direction are controlled to be synchronized on the basis of the respective reference timing signals.

The present invention relates to driving of a heater of a fixing unit in an image process apparatus. In case of driving first and second heaters by using a constant voltage output control circuit, when the first or second heater is switched from an ON state to an OFF state, an operation of the constant voltage output control circuit is stopped, thereby preventing destruction of circuit elements. Also, when the first heater is in the ON state and the second heater is switched from the OFF state to the ON state, the operation of the constant voltage output control circuit is stopped.

Control device with first and second power control elements to control

A digital motor drive control system comprises drive means for performing phase switching by use of the phase timing signal from phase switching timing generating means and driving of the motor in response to a PWM clock signal generated by PWM signal generating means where means is provided for synchronizing the PWM clock signal of the PWM signal generating means with a phase switching timing. The number of PWM clock pulses of each phase of the motor is made equal to each other, so that rotational irregularities of the motor are decreased.

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Susono, Japan

Kiyoto Toyoizumi