Canon Kabushiki Kaisha

Shoji Naruge

Ryohei Terada

Masahiro Ootsuka

Ichiro Katsuie

Shinya Suzuki

Takanori Iida

Osamu Ariizumi

Tatsuya Inoue

A developing device includes a rotatable developer carrying member enclosing a magnetic field generating portion including a plurality of magnetic poles and configured to carry a developer; and a resinous regulating portion provided at a position opposing the developer carrying member and configured to regulate an amount of the developer carried by the developer carrying member. The regulating portion is formed of a resin material containing magnetic powder, and at least a free end portion, opposed to the developer carrying member, of the regulating portion has relative permeability of 10 or more and 60 or less.

Developing device

An image forming apparatus including a toner container, a toner amount detection unit, a driving unit, a toner accommodating unit, a remaining toner amount detection unit, and a control unit is provided. The toner container supplies the toner to the toner accommodating unit by being rotated in a first direction. The toner amount detection unit detects a value related to an amount of the toner in the toner container. The control unit controls the driving unit so as to rotate the toner container in a second direction in a case where the remaining-toner amount detection unit has detected that the amount of the toner accommodated by the toner accommodating unit is smaller than a first set amount and the amount of the toner contained in the toner container detected by the toner amount detection unit reaches a second set amount.

Image forming apparatus

A development device wherein a magnetic force distribution of a developer bearing member in a longitudinal direction at positions at which a magnetic flux density of a low magnetic field area is minimal in the peripheral direction of the developer bearing member is set such that a difference between a maximum magnetic flux density in a range from a maximum position at which an attenuation rate of the magnetic flux density is maximal to a 30 mm distant position toward the center of the developer bearing member and a magnetic flux density on a further center side of the developer bearing member than the range is 3 mT or less, and an absolute value of the magnetic flux density of a further outer side in the longitudinal direction of the developer bearing member than the maximum position is set to 3 mT or less.

Development apparatus and image forming apparatus

A development device configured to develop an electrostatic image formed on an image bearing member by applying a developing bias in a development operation includes a developer bearing member configured to bear a developer, a bias applying unit configured to apply an input waveform bias including an alternating component to the developer bearing member, a bias detection unit configured to detect information concerning an output waveform bias generated on the developer bearing member when the bias applying unit applies the input waveform bias to the developer bearing member, and a controller configured to execute a mode for controlling the developing bias to be applied to the developer bearing member based on the input waveform bias and the output waveform bias.

Image forming apparatus using a controller configured to control a developing bias to be applied to developer bearing member based on a input waveform bias and an output waveform bias

When dynamic torques are Ts, Ti, and T, respectively, and rotation angle speeds are Rs, R, and R, respectively, at the time of rotations of the developing sleeveand the screwsand, the mass of the developer housed in the second agitating chamberis M, the mass of the developer which is present in the space of the side of the developing sleeve when a space formed by the developing chamberand the first agitating chamberis divided is Ms, the mass of the developer which is present in the space of the side of the screwis M, gravitational acceleration is G, each load on the developer by rotations of the developing sleeve and the screws is defined as Wds (mW/g)=Rs&#xd7;Ts&#xd7;G/Ms, Wd(mW/g)=RTG/M, and Wd(mW/g)=R&#xd7;T&#xd7;G/M, respectively, relationships of 0.5&#x3c;Wds/(Wd+Wd)&#x2266;7.0, 12.5&#x2266;Wds&#x2266;57.5, and Wd&#x3c;Wdare satisfied.

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Kashiwa, Japan

Shoji Naruge