Mita Industrial Co., Ltd.

Akira Nakakuma

Yasuyuki Fukunaga

Hideki Kita

Tetsuya Matsushita

Kikunosuke Tsuji

Masahiko Kubo

Kazuo Fuji

Noriaki Tsubota

Kazuhisa Edahiro

Hidehiro Fukui

Kiyoshi Morimoto

Hiroshi Kobayashi

Akihiro Watanabe

Masuo Kawamoto

Naruo Yabe

Hiroyuki Deguchi

Arihiro Tsunoda

Yoshihisa Kuramae

Hideaki Tsudaka

Yoshinobu Takemura

Toshimitsu Takeuchi

Toru Taniguchi

Toshio Nishio

A housing accommodating a fur brush and a cleaning blade is pivoted to a position close to a photoconductive drum and at another position far from the photoconductive drum by positioning a positioning shaft. When the positioning shaft is slid for moving the positioning shaft away from a photoconductive drum, an operating member attached to the positioning shaft is put into contract with a pivoting lever to raise the pivoting lever away from the photoconductive drum. Since the pivoting lever is attached to a blade shaft, a cleaning blade attached to the blade shaft is pivoted away from the photoconductive drum.

Positioning mechanism for a cleaning device provided in an image forming

A movable frame is mounted on a stationary frame so as to be reciprocatingly moved in a predetermined direction by a moving means. The movable frame is equipped with a plurality of developing mechanisms which may be selectively located at a developing position by the motion of the movable frame to carry out multi-color developing. The developing mechanisms are urged toward a rotary drum. In order to prevent the developing agent from scattering, side sealing pieces are provided near the non-developing operation region on both sides of a sleeve member in a magnetic brush mechanism of each developing mechanism. A toner container unit including toner containers and toner feeding means is rotatably supported by the stationary frame. The toner feeding means includes a extensible and contractible means which is detachably coupled to the developing mechanism. The toner container unit is selectively brought to a predetermined fixed position relative to the developing mechanism and to a predetermined retracted position turned in a direction to separate away from the developing mechanism.

Developing device

A movable frame is mounted on a stationary frame so as to be reciprocatingly moved in a predetermined direction by a moving means. The movable frame is equipped with a plurality of developing mechanisms which may be selectively located at a developing position by the motion of the movable frame to carry cut multi-color developing. The developing mechanisms are urged toward a rotary drum. In order to prevent the developing agent from scattering, side sealing pieces are provided near the non-developing operation region on both sides of a sleeve member in a magnetic brush mechanism of each developing mechanism. A toner container unit including toner containers and toner feeding means is rotatably supported by the stationary frame. The toner feeding means includes a extensible and contractible means which is detachably coupled to the developing mechanism. The toner container unit is selectively brought to a predetermined fixed position relative to the developing mechanism and to a predetermined retracted position turned in a direction to separate away from the developing mechanism.

The present invention provides a magnetic brush developing method using a two-component developer, characterized in that the development is carried out under such conditions that at the position where the sliding contact of the magnetic brush with the surface of the photosensitive material drum terminates, the following requirement is satisfied:

Magnetic brush development process

Disclosed is a developing process using a two-component type magnetic developer, where the main pole of developing magnetic poles in the developing sleeve is arranged upstream of the position, where a photosensitive drum becomes closest to the developing sleeve, in the rotation direction of the developing sleeve, this closest position between the drum and the developing sleeve is included in a region where the flux density in the magnetic force distribution of the main pole decreases toward the downstream side in the rotation direction of the sleeve, an alternating current voltage is applied between the developing sleeve and the drum to form an alternating electric field between the highest voltage and lowest voltage of the electrostatic latent image and in this state the development is carried out. According to this process, the conditions required for the supply of the developer are considerably moderated and an image having a high quality can be advantageously obtained.

Developing process using two-component type magnetic developer

A multicolor developing device having a plurality of developing mechanisms for executing developing with differrent colors. The developing device includes a stationary frame member, a movable frame member mounted on the stationary frame member to reciprocally move in a predetermined direction, and a moving device for reciprocally moving the movable frame member. The plurality of developing mechanisms are mounted on the movable frame member and maintaining a distance in the said predetermined direction. Any one of the plurality of developing mechanisms is selectively positioned at a developing zone depending on the movement of the movable frame member. The moving device includes a screw device having a threaded shaft extending in the predetermined direction and a nut engaged with the threaded shaft, a stepping motor for rotating the threaded shaft, and a nonexcited operation-type electromagnetic brake. A pair of racks are disposed on the stationary frame member and maintain a distance in the lateral direction, and the movable frame member is provided with a rotary shaft extending in the lateral direction and a pair of pinions fitted to the rotary shaft, the pair of pinions being engaged with the pair of racks. Each of the developing mechanisms is provided with a pair of distance-setting rollers which are brought into resilient contact with a rotary drum in order to accomplish the positioning of the developing mechanism relative to the rotary drum.

Multicolor developing device with improved movable frame arrangement

Guided through a sliding member by a guide member set before a photoreceptor, a plurality of developing units approach the photoreceptor in turn and face the photoreceptor, thereby to develop, at an open portion of the guide member with being projected by an enforcing member.

Developing apparatus having developing units with a sliding member

The present invention relates to various improvements in a scanning optical device having a pair of supporting members spaced from each other in a width-wise direction and an optical element assembly mounted reciprocably on the pair of supporting means. According to one aspect of the invention, the optical element assembly includes a supporting frame having optical elements mounted on it and support portions to be supported by the pair of supporting members, and at least one of the support portions is mounted on the supporting frame such that its position can be freely adjusted. According to another aspect of the invention, the optical element assembly is reciprocated by a front and a rear power transmission mechanism, and the front and rear power transmission mechanisms and a common driving source are disposed between a front and a rear upstanding base plate in which the pair of supporting members are provided. According to still another aspect of the invention, the front and rear power transmission mechanisms each include an input wire drum drivingly connected to the common driving source, and a wire for moving the optical element assembly is wrapped around the input wire drum through a plurality of turns. According to a further aspect of the invention, a notch for facilitating provisional wire anchorage is provided, and at the time of wire wrapping, the wire is provisionally anchored at the notch.

Scanning optical device having at least one reciprocating optical

A supporting apparatus for optical unit having an optical unit to expose an original set on a contact glass, a reciprocatingly movable supporting frame body equipped with the optical unit, a sliding member provided on both ends of the supporting frame body, and an eccentric cam mechanism provided on one end of the supporting frame body to vertically adjust one of the sliding member. By operating the eccentric cam mechanism, one end of the supporting frame body can be adjusted to a desired height so as to enable to adjust horizontality of the optical unit mounted on the supporting frame body. Furthermore, because a large gap is provided between a pair of sliding members provided on one end of each supporting frame body and the ends of the two supporting frame bodies where the sliding members are mounted are mutually disposed at reverse side, both supporting frame bodies can be caused to come as close at their home positions as possible.

Support and adjusting apparatus for an optical unit

A document size detecting device with the arm which folds by interlocking with the reciprocating motion of the optical system of the image forming apparatus and extends and contracts by interlocking with the reciprocating motion of the optical system. The optical sensor for detection of the document size is installed at a prescribed position of the arm and the feeder line for the light source is held. Therefore, the special mechanism for holding the feeder line is not necessary and it is possible to achieve simplified construction of the image forming apparatus. Also, because the feeder line is caused to curve along the outside of the arm at the rotating section thereof, it is possible to provide a large radius of the bent portion of the feeder line, there will be no considerably concentrated stress which is locally applied to the feeder line, therefore the life of the feeder line can be extended.

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Takaishi, Japan

Akira Nakakuma