Kabushiki Kaisha Toshiba

Toshiba Tec Kabushiki Kaisha

Other

Mitsuhisa Kato

Takahito Kabai

Satoshi Itaya

Norikazu Ochiai

An image forming apparatus according to an embodiment includes a decolorable image forming unit that forms a decolorable image with a decolorable material. A mask control unit controls the decolorable image forming unit to form, with the decolorable material on a sheet, a mask that hides at least one portion of an image formed on the sheet with non-decolorable material.

Image forming apparatus and mask forming method

A developing roller according to the invention includes a columnar magnet roller, and a cylindrical sleeve that houses the magnet roller. A plurality of fragmented micro recesses is formed on the surface of the sleeve. The micro recesses are arranged dispersively both in an axial direction and in a circumferential direction of the sleeve.

Developing roller, developing apparatus, and image forming apparatus

An image-forming apparatus includes a rotary developing device including a casing having absolute value of the surface potential of not larger than 300 V.

Image forming apparatus and method for forming image

Image forming apparatus having a rotary developing device with plural developing units

In an image forming apparatus according to the invention, the potential of an optical semiconductor is increased in a predetermined time period, in which a recording medium does not exist in a transfer region between the optical semiconductor and a transfer unit, so as to set a difference between a developing bias voltage and the potential of the optical semiconductor larger than a difference therebetween assumed when toner is being transferred onto the recording medium.

Method and apparatus for use in image forming apparatus

An image forming device is provided including a plurality of developing devices changeable between at least a developing position and a standby position. The image forming device estimates a toner coverage rate for a first developing device at the developing position. If the estimated toner coverage rate is higher than a predetermined value, the first developing device is replenished with toner when a first print is printed before being changed to the standby position. If the estimated toner coverage rate is equal to or less than the predetermined value, the first developing device is replenished with toner before being changed to the developing position for a second print from the standby position.

Image forming apparatus and toner supply device and method used in image forming apparatus

A fixing device in an image forming apparatus can set its fixing temperature to 200.degree. C. in the copy mode, and 180.degree. C. to 160.degree. C. in the printer mode. When print data is externally input, a print mode is set, and the copy mode can be set on the image forming apparatus side. Since a fixing temperature is selected in accordance with the mode, a deterioration in image quality due to a fixing operation can be prevented, and both a high fixing ratio and high image quality can be realized.

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Yokohama, Japan

Mitsuhisa Kato