Sharp Kabushiki Kaisha Corporation

Hideji Saikoh

Kazuma Hinoue

Motoyuki Itoyama

Masayasu Narimatsu

Kiyofumi Morimoto

Takeshi Ohkawa

Junichi Saito

Mitsuru Tokuyama

Eiichi Kido

Takayuki Yamanaka

Yasuhiro Nishimura

Kohichi Takenouchi

Tomoki Minamikawa

An image forming apparatus that includes a charger for charging a surface of a photoreceptor and that forms an image by using an electrophotographic system, the charger being configured to be cleanable, includes a guidance notification unit that causes a guidance notification prompting cleaning of the charger to be displayed and a guidance notification determination unit that, in accordance with a threshold set in accordance with usage condition of the image forming apparatus, determines whether or not to cause the guidance notification to be displayed.

Image forming apparatus including displayed notification to prompt cleaning of charger and storage medium

The image forming apparatus carries out a monitoring operation in which (i) sensor outputs of the magnetic permeability sensor are periodically sampled, (ii) a time period, corresponding to one (1) circulation period which is required for the developer to be circulated once in the circulation carrying path, is evenly divided into a plurality of blocks, and (iii) an average of the sensor outputs in one (1) block time period corresponding to one (1) block is calculated for each of the plurality of blocks; and determines that toner has run short, in a case where the number of times that the averages of the sensor outputs consecutively exceed a threshold, set to be higher than a reference value of the sensor outputs, becomes not less than the number of the plurality of blocks which correspond to the time period corresponding to one (1) circulation period.

Method for judging toner shortage and image forming apparatus

Provided are an image forming apparatus that, when a difference between a developing bias in correcting an image density and a reference developing bias has a value not less than a prescribed value that is set preliminarily, replenishes or consumes a toner forcibly, executes correction of the image density again, and controls the developing bias in such a manner that a toner density is controlled to fall within an appropriate range, and an image forming method using the same. When a difference between a developing bias value after correction of the image density and the reference developing bias becomes larger than the prescribed value to the plus side or the minus side, a toner density control portion performs control to consume or replenish a toner forcibly.

Image forming apparatus, and image forming method

An image forming apparatus prevents printed images from being degraded in image quality due to failure of the toner concentration to fall within a proper range, by correcting the deviations of the amount of toner consumption and the amount of toner supply depending on the individuality of each image forming apparatus and that enables exact identification of the cause of a fault associated with toner concentration, and providing an image forming method using the apparatus. A toner supply device supplies toner to a developing vessel through an opening in accordance with an instruction from a controller. The presence or absence of toner falling is detected based on the variation of the output from a magnetic permeability sensor when toner is supplied. The controller monitors the output voltage level of the magnetic permeability sensor and adjusts the input gain in accordance with the output voltage level to thereby control toner concentration.

Image forming apparatus and image forming method using the same

An image forming apparatus includes a developing device having a toner supply sensor, a toner supply device supplying toner to the developing device, a toner supply controller controlling toner supply from the toner supply device to the developing device based on predetermined conditions, a toner empty determiner determining whether toner is present inside the toner supply device. In the image forming apparatus, the toner supply device includes a storage for recording multiple measured values of toner supply detected by the toner supply sensor, and the toner supply controller corrects the amount of toner supply, based on the moving average of multiple measured values of the amount of toner supply.

Image forming apparatus and toner supply method

An image forming apparatus includes: a latent image bearing member on which an electrostatic latent image is to be formed; a developing unit which contains the developer and performs a development process to develop the electrostatic latent image formed on the latent image bearing member; and a movement mechanism which moves the developing unit toward the latent image bearing member when the development process is performed, and moves the developing unit away from the latent image bearing member and changes the attitude of the developing unit with, respect to the latent image bearing member when the development process is not performed.

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Osaka, Japan

Hideji Saikoh