Kabushiki Kaisha Toshiba

Toshiba Tec Kabushiki Kaisha

Other

Taizo Nozawa

Noboru Furuyama

Hiroshi Katakura

Setsuo Takada

Satoshi Itaya

Yukio Futamata

An embodiment provides an image forming apparatus including: a job acquiring unit that acquires an image forming job that gives instructions for performing forming of an image; an image forming process control unit that controls performance of the image forming job that the job acquiring unit acquires; a temperature information acquiring unit that acquires information showing temperature of the heating rotary body; a determining unit that determines whether the temperature of the heating rotary body which is acquired by the temperature information acquiring unit is equal to or higher than a predetermined stand-by temperature set as a temperature in a stand-by state that stands by to perform the image forming process, when the image forming process is completed, based on the image forming job by the image forming process control unit; and a fixing device control unit.

Image forming apparatus, control method, and recording medium

Each picture element of an image is divided into a plurality of picture elements, a latent image corresponding to the divided picture elements is formed on a photosensitive member, and the latent image is then developed with a developing agent to print it on a paper-sheet. Then, there is counted the number G of the divided picture elements which become targets of the development among the divided picture elements.

Image forming apparatus and method for controlling the apparatus

Method and image forming apparatus having a picture element counter

The image density control method in the image forming apparatus including the charging unit for charging the photoconductor, the exposure unit for exposing the photoconductor and forming an electrostatic latent image, and the developing unit for visualizing the electrostatic latent image with toner comprises a step of forming a predetermined reference image by the developing unit, a step of detecting the toner density of the reference image, a step of setting a target density value or the reference image formed on the photoconductor according to the number of images to be formed, and a step of controlling so as to change at least one of the charging potential to be given to the photoconductor from the charging unit, the exposure amount at the time of exposure from the exposure unit to the photoconductor, and the development bias voltage given to the developing unit on the basis of the comparison result of the value detected at the detection step with the target density value set at the setting step.

Image forming apparatus having toner density detection and image density control method therefore

A developing device includes a charger configured to charge a surface of an image carrier uniformly during its movement, an exposure unit configured to expose an optical image to form an electrostatic latent image on the charged image carrier, a developing unit provided facing the image carrier to supply developing agent to the image carrier to develop the electrostatic latent image. The developing unit includes a first developing roller and a second developing roller arranged at the down stream side of the first developing roller in the moving direction of the image carrier. Further, the developing device includes a bias voltage transformer configured to apply a bias voltage to the first and second developing rollers, a controller configured to control the bias voltage transformer to apply a regular bias voltage of the same polarity as the charged image carrier to the first developing roller when the leading edge of the charged area on the image carrier passes the position facing the first developing roller after the charging to the image carrier has started, and a driver to configured to start to drive the developing unit before the leading edge of the electrostatic latent image formed on the image carrier passes the position facing the first developing roller after the controller controls the bias voltage transformer to apply the regular bias voltage.

Developing device for developing a latent image

A developing device using developer and an image carrier has of a developing roller to carry developer, to feed developer to image carriers and to form a developer image. The developing device also has an upper mixer screw, which conveys, developer to the developing roller while stirring it, and a lower mixer screw provided under the upper mixer screw, which circulates and conveys developer jointly with the upper mixer also, the developing device has a drawing up roller with first and second magnetic poles formed to draw up developer when the lower mixer screw feeds developer to the upper mixer screw. The drawing up roller has magnetic matter provided in contact with the drawing up roller so as to form an angle 90.degree. or below to the horizontal line passing through the center of axis of the developing roller between the first and second magnetic poles so that developer which is drawn up by the drawing up roller, separates so that it is re-circulated by the upper mixer screw.

Developing device

An image forming apparatus of the present invention includes a latent image forming unit to form an electrostatic latent image on a charged image carrier, a developing device to form a developer image by developing the electrostatic latent image formed on the image carrier by a developer and a charge removing unit to discharge the image carrier before transferring the developer image and reduce the electrostatic adsorbing power of the developer image to the image carrier. The charge removing unit includes a charge removing light source to apply the charge removing light to the image carrier and the developer image and the charge removing charger to remove the charge by discharging the image carrier and able to control the discharge output. The charge removing unit is controlled to be adjusted a charge removing capacity.

Image forming apparatus having pre-transfer charge removing means

A magnetic brush type developing device of the type used for electrophotography includes a developing roller and a carrier recovery roller, each of which includes a non-magnetic sleeve and a permanent magnet disposed within the non-magnetic sleeve. The developing roller is positioned adjacent to a photostatic body bearing an electrostatic latent image. During use the developing roller is rotated to transfer a two-component developing agent, comprised of a carrier and a toner, onto the photosensitive body. The carrier roller faces the photosensitive body and includes a permanent magnet having an orientation and a magnetic force that will cause the carrier component of the two-component developing agent to transfer from the photostatic body to the carrier roller during rotation of the carrier roller.

Growing community of inventors

Kanagawa-ken, Japan

Taizo Nozawa