Toshiba Tec Kabushiki Kaisha

Yuichiro Takeda

Hisanobu Ajima

Nobuo Tohata

A toner is comprised of toner particles and external additive adhering to the surface of the toner particles. The toner particles are formed from a binder resin, an ester wax, and a colorant. The external additive comprises a titanium oxide and silica. A first adhesive strength between the external additive and the toner base particles is in a range of 90 to 100% when measured as a ratio of X-ray spectroscopic intensity of titanium for toner particles before and after a washing process, and a second adhesive strength between the external additive and the toner base particles is in a range of 50 to 80% when measured as a ratio of X-ray spectroscopic intensity of silicon measured for toner before and after another washing process.

Toner, toner cartridge, image forming apparatus

A toner according to an embodiment includes toner base particles and an external additive. The external additive contains silica particles having a Dof 70 to 120 nm. The joining degree of the silica particles is 80% or more. The toner base particles contain a crystalline polyester resin and an ester wax. The ester wax is a condensation polymer of three or more types of carboxylic acids and two or more types of alcohols. The proportion of a carboxylic acid, the content of which is highest, is between 70 and 95 mass %. The proportion of a carboxylic acid with a carbon number of 18 or less is 5 mass % or less. The proportion of an alcohol, the content of which is highest, is between 70 and 90 mass %. The proportion of an alcohol with a carbon number of 18 or less is 20 mass % or less.

Toner, toner cartridge, and image forming apparatus

According to one embodiment, an image forming apparatus includes: an image forming unit configured to form a toner image using a first toner supplied to the image forming unit with a first process bias VR; a density sensor configured to detect a density of toner in the image forming unit; a toner cartridge containing a second toner and including a memory that stores data representing a process bias VA appropriate for the second toner; a mounting unit on which the toner cartridge is mounted; and a toner replenishing unit configured to replenish the image forming unit with the second toner from the toner cartridge mounted on the mounting unit based on the density, in which a density detected by the density sensor when the toner cartridge is mounted on the mounting unit is converted into an estimated amount, and the image forming unit is set to a process bias V until the image forming unit is replenished with the second toner by the estimated amount after the toner cartridge is mounted on the mounting unit, the process bias V being obtained from the following formula V=VA&#x2212;((VA&#x2212;VR)/the estimated amount)&#xd7;(an amount of the second toner with which the image forming unit is replenished after the toner cartridge is mounted on the mounting unit).

Image forming apparatus with process bias setting

According to one embodiment, an image forming apparatus includes a developing device, a sensor, a control information obtaining unit, and a control unit. The developing device forms an image on an image carrier using a developer. The sensor generates a signal indicating a measurement value related to the developer. The control information obtaining unit obtains, as control information of the developing device, one or more pieces of the control information pre-associated with the measurement value, from a recording medium associated with the developer. The control unit selects the control information associated with the measurement value indicated by the signal, from the one or more pieces of control information obtained from the recording medium. The control unit controls an operation of the developing device based on the selected control information.

Growing community of inventors

Fuji Shizuoka, Japan

Yuichiro Takeda