Canon Kabushiki Kaisha

Kana Oshima

Shusuke Miura

Jiro Shirakata

Koichi Taniguchi

Jun Nakazato

An image forming apparatus includes an image forming unit having a photosensitive member on which an image is formed and a developer bearing member, an intermediate transfer member onto which the image is transferred, a transfer member forming a nip portion for transfer of the image on the photosensitive member onto the intermediate transfer member, a transfer unit transferring the image on the intermediate transfer member onto the sheet, a motor rotating the photosensitive member, a motor control unit controlling the motor so the rotation speed of the photosensitive member is a target rotation speed, and a controller that acquires first and second load information of the photosensitive member in a first period where developer bearing member rotates and a second period where developer bearing member is stopped, and controls whether or not to change the target rotation speed based on the first and second load information.

Image forming apparatus

An image forming apparatus includes an image forming unit, a fixing unit having a heating member for generating heat based on power supplied, a detection unit, and a controller. The image forming unit forms an image on a sheet. The fixing unit fixes the image on the sheet by the heat of the heating member. The detection unit detects a temperature of the heating member. The controller controls power to be supplied to the heating member based on a temperature detected by the detection unit. The controller determines a difference value between the temperature detected by the detection unit and a target temperature, determines an accumulated value by performing accumulation processing of the difference value, and controls the power based on the difference value and the accumulated value. The controller controls the accumulation processing based on the difference value and the accumulated value.

A position detection apparatus detects a position of a target object. One end of a swinging member contacts the target object, and the other end contacts a moving member. (M+1) pieces of sensors are arranged to output signals corresponding to a position of the moving member. Measured parts are disposed on the moving member along loci of measuring positions of the sensors. A detection unit detects the position of the target object based on the output signals of M pieces of sensors when the other sensor outputs a predetermined signal. The measured parts corresponding to the other sensor are provided in 2pieces of divided areas that are disposed along a locus corresponding to the other sensor. Each of the measured parts corresponding to the other sensor is disposed in a center portion except both ends in the moving direction in each of the divided areas.

Position detection apparatus that detects position of target object

A position detection apparatus detects a position of a target in a predetermined direction. One end of a swinging member contacts the target, and the other end contacts a moving member. Sensors are arranged to output signals corresponding to a position of the moving member that corresponds to a position of the moving member. A detection unit detects the position of the target based on the output signals of the sensors. Measured parts are disposed on the moving member along loci of measuring positions of the sensors so that the sum total of the output signals becomes an even number. The detection unit determines that any one of the sensors failed in a case where the sum total of the output signals of the sensors is an odd number.

Position detection apparatus that detects position of target

An image forming apparatus includes a latent image forming unit that forms an electrostatic latent image on an image carrier based on an image signal, a development unit that includes a circulation mechanism that circulates developer in the development unit and develops the electrostatic latent image using the developer, and a detector unit that detects a toner density of the developer in the development unit. A determination unit determines a replenishment amount of toner to the development unit based on the toner density detected by the detector unit, and a replenisher unit replenishes the development unit with toner based on the determined replenishment amount. The determination unit reduces a predetermined ripple that occurs in accordance with a period of circulation of the developer by executing filter processing for reducing the predetermined ripple.

Image forming apparatus for executing developer replenishment control

An image forming apparatus includes a photosensitive member, an exposure unit, a developing unit that develops an electrostatic latent image using toner, a detection unit that detects an amount of the toner contained in the developing unit, and a calculation unit that calculates a difference value between the amount of detected toner detected and a target toner amount. In addition, an accumulation unit accumulates the calculated difference value, and a controller controls toner replenishing based on the calculated difference value and the accumulated value. A determination unit determines, based on an amount of the consumed toner and an amount of the contained toner, whether or not an error of an amount of replenished toner is larger than a threshold value, and determines, based on the number of times that the error is determined, whether or not replacement of the container is required.

Image forming apparatus that performs developer replenishment

A replenishment unit replenishes a storage unit with toner. A detection unit detects a toner density of developer in the storage unit. A stoppage unit stops, based on the toner density, an image forming operation. A first calculation unit controls the detection unit to detect the toner density in a duration from when the operation stops to when the image forming unit resumes the operation, and calculates a difference between the toner density and a target. A second calculation unit accumulates the difference to obtain a cumulative value. A determination unit determines a value for determining whether or not replenishment of the toner is required, based on the difference calculated and the cumulative value calculated. A controller controls a timing at which the replenishment unit replenishes the storage unit with the toner in the duration based on the value.

Image forming apparatus for reducing fluctuation of toner density in a developing unit

A latent image forming unit forms an electrostatic latent image on a photosensitive member. A developing unit includes a container. The container stores toner. A circulating unit circulates the toner in the container. The developing unit develops the electrostatic latent image using the toner. A replenishment unit replenishes the developing unit with toner. A detection unit detects a density of the toner in the container. An acquisition unit acquires a circulation period at which the circulating unit causes the toner to circulate. A determining unit determines a correction condition based on the circulation period. A correction unit corrects a detection result of the detection unit based on the correction condition. A controller controls the replenishment unit based on the detection result corrected by the correction unit.

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Kana Oshima