Mita Industrial Co., Ltd.

Hiroyuki Hazama

Masaru Watanabe

Takashi Terada

Hirotsugu Ogawa

Masanobu Maeshima

Masahiro Tsutsumi

Takahiko Murata

Nariaki Tanaka

Hiroyuki Hamakawa

Hidehiro Tabuchi

Kazuhiro Mizude

Hidekazu Sakagami

Nobuhiro Nakajima

Toru Ueno

Eiichi Miyamoto

Yukio Hashimoto

Mamoru Kato

Hideo Nakamori

Yoshiyuki Takeda

Junichi Oura

Takashi Teshima

Yukinori Akiyama

Kouji Maekawa

Hiroaki Shiba

Koji Honda

Masayuki Ishii

Takatomo Fukumoto

Kyouya Taguchi

Kazuhiko Yamamura

Masaru Goto

Kenichi Matsunobu

Masaru Gotoh

Naoka Fujie

Takeshi Higuchi

An electrostatic latent image developing device equipped with a developing housing, a developing roller rotatably disposed between the two side walls of the developing housing, and a feeding roller rotatably disposed between the two side walls of the developing housing neighboring the developing roller. A first bearing member is mounted on one side wall and has two bearings for supporting the ends of the rotary shafts of the developing roller and the feeding roller. A second bearing member is mounted on the other side wall and has a bearing for supporting the opposite end of either the rotary shaft of the developing roller or the feeding roller. A third bearing member is mounted on the other side wall and has a bearing for bearing support of the opposite end of the rotary shaft of the developing roller or the feeding roller not supported in bearing fashion by the second bearing member. The second bearing member and the third bearing member are provided with a positioning device for defining a relative positional relationship between the second and third bearing members.

Electrostatic latent image developer with shaft bearing members

A charging device is provided which is suitable for use in a compact electrophotographic image forming apparatus. The charging device includes: a pair of support members spaced a predetermined distance; and a discharge wire stretched between the pair of support members with one end thereof being fixed to one of the support members and with a middle portion thereof being supported by the other support member. One end of a coil spring is connected to the other end of the discharge wire, and the other end of the coil spring is received by a hooking portion of an electrode. The electrode is fixed in the vicinity of one of the support members.

Charging device having a charger arrangement frame in which a discharge

Developing unit for forming an image

An image-forming machine includes a photosensitive drum rotatably disposed; a charger for electrically charging the peripheral surface of the photosensitive drum to a predetermined polarity; a developer for developing an electrostatic latent image formed on the peripheral surface of the photosensitive drum into a toner image; a transfer device for transferring the toner image formed on the peripheral surface of the photosensitive drum onto a transfer paper; a fixing roller for heat-fixing the toner image transferred onto the transfer paper by the transfer device; and a cooling fan for blowing cooling air to the surrounding area of the fixing roller. A guide plate having a plurality of openings formed along its length, guides the transfer paper onto which the toner image has been transferred by the transfer device, to the fixing roller.

Image-forming device and a process unit therefor having a guide plate

An image forming machine including a single layer dispersion type photoconductor drum, a charging device for charging the surface of the photoconductor drum to a specific polarity, and a developing roller for conveying a developer to the surface of the photoconductor drum having a latent electrostatic image formed thereon. The photoconductor drum and the developing roller are adapted to contact each other at their surfaces and to be rotationally driven in reverse directions. The photoconductor drum has a diameter set at 10 to 20 mm, while the developing roller has a diameter set at 90 to 110% of the diameter of the photoconductor drum.

Image forming machine with a contact type developing device

A transferring device in which a transfer roller having a diameter which is not less than 60% of the diameter of an organic photosensitive drum with a diameter of 10 to 20 mm is arranged with a clearance provided between the transfer roller and the organic photosensitive drum. The transferring device avoids problems such as current leakage and reverse transfer of toner in the case of miniaturization of an image forming apparatus or contamination of the transfer roller, and easily sets a transfer current because an effective transfer current width is large.

Transferring device and image forming apparatus using the same

An image-forming machine including a photosensitive drum which is rotatably disposed and successively passes through a charging zone, a developing zone and a transfer zone; a charger for charging the peripheral surface of the photosensitive drum into a predetermined polarity; a developing device for developing an electrostatic latent image formed on the peripheral surface of the photosensitive drum into a toner image; a transfer means for transferring the toner image formed on the peripheral surface of the photosensitive drum onto a transfer paper; and a foreign matter-recovering means which is disposed between the transfer zone and the charging zone and comes into contact with the peripheral surface of the photosensitive drum, and removes foreign matter adhered onto the peripheral surface of the photosensitive drum, the foreign matter-recovering means having a foreign matter-recovering brush brought into contact with the peripheral surface of the photosensitive drum, an elastic holding member made of an elastic material mounting said foreign matter-recovering brush, and a brush-support member for supporting said elastic holding member, and the foreign matter-recovering brush being press-contacted to the peripheral surface of the photosensitive drum by the compressive elastic force of the elastic holding member.

Image-forming machine

A process unit including a photoconductor unit having a photoconductor drum, a developing unit having a developing roller disposed in a development housing, and a support shaft means for supporting the developing unit pivotably relative to the photoconductor unit. The developing roller is disposed such that its surface is pressed against the surface of the photoconductor drum in a developing zone. The photoconductor drum and the developing roller are rotationally driven such that their respective surfaces move from below to above in the developing zone.

Process unit

According to the present invention, in the image forming apparatus in which so-called 'cleaningless' is realized, no problems such as traces of paper powder, gray or foggy stripes and the like occur in a formed image. The image forming apparatus is provided with a brush for scratching toner remaining on the surface of the photosensitive drum and recovering paper powder adhering on the surface thereof. When the length of the brush extending from the root thereof to the photosensitive drum is taken as a�mm!, the length of the toughening member, toughening the brush materials, projecting from the root of the brush materials is taken as c�mm!, and the length of the portion of the brush, cutting into the photosensitive drum, is taken as b�mm!, the relationship among a�mm!, b�mm! and c�mm! satisfies the conditions that 0.3.ltoreq.(c/(a+b)).ltoreq.0.95, 0.1 �mm!.ltoreq.b.ltoreq.1.5 �mm!, and (a+b)&lt;2 �mm!.

Image forming apparatus having a toner brush equipped with a toughening

An image-forming apparatus for forming image through the electric charging of a photosensitive material drum, exposure to light, developing and transfer, wherein a developing device also works to clean the toner remaining on the photosensitive material; an electric charge for effecting the electric charging has a scorotron charger located within .+-.45.degree. from a perpendicular downwardly drawn from the center of the photosensitive material drum, and has a hole on the side opposite to the opening for charging; and an electric field E.sub.1 between a wire and a grid in the scorotron charger is set to be stronger than an electric field E.sub.2 between the wire and a shield. The invention is further concerned with an image-forming unit used in the image-forming apparatus for forming image wherein said image-forming unit includes a photosensitive material drum having a photosensitive layer of an organic material, a first frame for supporting the photosensitive material drum maintaining the freedom of rotation, a photosensitive material unit having a scorotron charger which is provided on the first frame so as to be positioned within .+-.45.degree. from a perpendicular downwardly drawn from the center of the photosensitive material drum and has a ventilation hole on the side opposite to the opening for charging, a developing device, and a second frame which supports the developing device and also works as a toner container; wherein the first frame and the second frame have a common fulcrum and a resiliently engaging device on the side opposite to the fulcrum, and an electric field E.sub.1 between a wire and a grid in the scorotron charger is set to be stronger than an electric field E.sub.2 between the wire and a shield.

Image-forming apparatus and image-forming unit

An image forming apparatus including a photoreceptor, an electrically charging unit for evenly electrically charging the photoreceptor to a predetermined potential, a light exposure unit for exposing a surface portion of the evenly electrically charged photoreceptor to light so as to form an electrostatic latent image, a developing unit for causing toner to adhere to the photoreceptor surface portion exposed to light so as to develop the electrostatic latent image into a toner image, and a transferring unit to which a predetermined transferring voltage is applied for transferring the toner image to a sheet. Before the tip end of the toner image reaches the position opposite to the transferring unit but after the tip end of the sheet has reached the position opposite to the transferring unit, the application of the predetermined transferring voltage to the transferring unit is started.

Image forming apparatus having a transferring unit improved in

A process unit comprising a photoconductor unit and a developing unit supported pivotably via a support shaft. The photoconductor unit and the developing unit each have a pair of support side walls having support holes formed on the same axis. One pair of the support side walls define a pair of inner support side walls having an outside width smaller than the inside width of the other pair of the support side walls, while the other pair of the support side walls define a pair of outer support side walls. The pair of outer support side walls and the pair of inner support side walls are supported via the support shaft passing through the respective support holes. One end of the support shaft is supported by one of the outer support side walls via a bearing member detachably mounted in the support hole of the one of the outer support side walls.

A process unit of an image forming machine, comprising a photoconductor unit including a photoconductor drum, and a developing unit for developing a latent electrostatic image formed on the photosensitive layer of the photoconductor drum to a toner image, the photoconductor unit and the developing unit being connected by a support shaft so as to be pivotable relative to each other; in which a pre-transfer guide plate for guiding a transfer sheet to be conveyed to a transfer zone is disposed on a photoconductor support means for supporting the photoconductor drum rotatably, and the rear surface of the pre-transfer guide plate is brought into contact with the support shaft or a development housing.

Process unit of image forming machine having pre-transfer guide

An electrographic copying machine has a photoreceptor drum which moves so that a photosensitive layer on its surface is successively charged, exposed, developed and charge-removed. The photosensitive layer is made of an amorphous material. The drum surface is charged by a charger before a latent image is formed thereon through exposure. A voltage generator is provided which supplies the charger with a voltage to charge the drum surface. It takes time for the potential of the charged drum surface at the developing section to reach a predetermined potential from a potential higher than the predetermined potential due to a rise characteristic of the surface potential. A controller is provided which corrects an output voltage value of the voltage generator to a voltage value necessary for the drum surface to be charged at the predetermined potential in a predetermined number of charging operations performed until the surface potential reaches the predetermined potential.

Voltage control apparatus for controlling a charger in an image forming

In a copying processing performed several times from the depression of a copy button of a copying machine until the surface potential of the photoreceptor drum is stabilized, a voltage sufficiently high for correcting the rise characteristic of the photosensitive layer on the drum surface is applied to a charger. A main circuit having a controlling portion to realize this corrects the output voltage of the high-voltage generating circuit which applies a high voltage to the charger to a voltage value necessary for the drum surface to be charged at a stable potential level. The main circuit charges the drum surface at the stable potential level necessary for development from copying of the first sheet.

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Osaka, Japan

Hiroyuki Hazama