Kabushiki Kaisha Toshiba

Toshiba Tec Kabushiki Kaisha

Chie Tonohiro

Takafumi Hara

Atsushi Kubota

Ryozo Akiyama

Maiko Yoshida

Hiromichi Mitamura

According to one embodiment, the image forming apparatus includes an image carrier the surface of which is charged at a predetermined potential, an exposure device which forms a latent image by exposing the surface of the image carrier, a developing unit which develops a toner image generated using color erasable toner on the latent image formed on the surface of the image carrier, a transfer unit which transfers the toner image to a recording medium, and a controller which controls an operation for transferring a toner image of the color erasable toner to a printed surface of the recording medium to cover a printed portion of the recording medium to which the color erasable toner has been fixed.

Image forming apparatus and image forming method for forming an image covering another image by a color erasable recoding material

According to one embodiment, an aqueous inkjet ink includes a dispersion medium that contains water and a water-soluble polyhydric alcohol having a weight average molecular weight of 400 or more, and a pigment. The pigment accounts for less than 5 mass % of the total amount of the aqueous inkjet ink. The aqueous inkjet ink has viscosities (mPa&#xb7;s) measured using a cone-plate type viscometer at 20 rpm and satisfying the following relationships:&#x2267;1.5&#x2267;10 mPa&#xb7;s3 mPa&#xb7;s&#x2266;&#x2266;15 mPa&#xb7;s,where Vis the viscosity at 30&#xb0; C., and Vthe viscosity at 45&#xb0; C.

Aqueous inkjet ink

A developing unit that includes a stirring roller stirring a developer and a developing roller and develops an electrostatic latent image formed on an image carrier to form a toner image; a drive source that rotationally drives the developing roller and the stirring roller; and a control unit that switches a rotational speed of the developing roller in modes of an image formation mode and an adjustment mode, and rotationally controls the stirring roller at a first speed in the modes are provided.

Growing community of inventors

Shizuoka-ken, Japan

Chie Tonohiro