Sharp Kabushiki Kaisha Corporation

Shuhichi Morikuni

Shoji Tomita

Takahiko Kimura

Tsutomu Nagata

Takashi Hirota

Akiko Tsuji

Toru Yosioka

An image forming apparatus includes a toner replenishing device that supplies toner, based on a detection result from a sensor that detects a toner density in a developing device that develops an electrostatic latent image based on an image signal with toner, so that the toner density takes a given value, a memory portion that counts a time for toner replenishment actually carried out by the toner replenishing device to accumulate count results as an accumulated actual toner replenishment time, a memory portion that calculates an expected required time for toner replenishment based on the image signal to accumulate calculation results as an accumulated expected toner replenishment time, and a determining portion that determines in given timing whether or not to execute the image quality adjusting processing, based on a difference between the accumulated actual toner replenishment time and the accumulated expected toner replenishment time.

Image forming apparatus, and method and program for determining timing to execute image adjusting processing

Provided is an image forming apparatus including a charging device for charging a photoreceptor drum, a developing device for developing an electrostatic latent image formed on the photoreceptor drum, a developing bias applying device for applying a developing bias voltage to the developing device, a toner image density sensor for detecting an image density of a toner image formed on the photoreceptor drum, and a control portion for controlling an output value of the developing bias applying device, in which the control portion adjusts the developing bias voltage based on an average print coverage of document in previous printing jobs.

Image forming apparatus and image forming method and developing bias voltage adjustment therein

An image forming apparatus is provided having a mechanism that toner density of a toner image is automatically adjusted based on a toner patch. In an image forming apparatus including a document conveying section, a document reading section, an image forming section, a sheet discharging section, a sheet feeding section, a patch density detecting section, and a toner density adjusting section for adjusting density of a toner image depending on a result detected by the patch density detecting section, there are further provided a patch forming section for forming a toner patch, an operation detecting section for detecting an operating state of the patch density detecting section, and a patch printing section for printing the toner patch in response to such a result detected by the operation detecting section that the patch density detecting section does not properly operate, thereby adjusting the toner density based on the patch image.

Image forming apparatus and method with process control for stably forming images

A toner supplying device includes: a toner density sensor for detecting a density of toner contained in a developer tank; a toner hopper for supplying toner to the developer tank; a toner cartridge for supplying toner to the toner hopper; and a control section, when a request to supply toner to the developer tank is made in accordance with a signal detected by the toner density sensor, for controlling a hopper driving motor and a cartridge driving motor so that (i) the toner hopper supplies toner to the developer tank and (ii) the toner cartridge supplies toner to the toner hopper. Thus, in a structure having first and second toner supplying sections disposed on top of each other, toner can be stably supplied to a developer tank.

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Nara, Japan

Shuhichi Morikuni