Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Minolta Camera Co., Ltd. Senri Center

Ricoh Company, Ltd.

Masashi Yamamoto

Toshiya Natsuhara

Akihito Ikegawa

Yuji Enoguchi

Keiko Nagayasu

Hiroshi Mizuno

Masaki Asano

Hitoshi Saito

Isao Doi

Masahiko Matsuura

Koji Uno

Takaji Kurita

Izumi Osawa

Junji Machida

Ichiro Demizu

Toshimitsu Fujiwara

Seishi Ojima

Kouichi Etou

Makoto Shimazoe

Akihiro Kawasaki

Fumio Masuda

Kazuko Taniguchi

Yuuji Enoguchi

Toru Miyasaka

Kenji Mori

Akira Sasaki

Masaru Nakano

A non-fixing type image receiving sheet to which toner particles are made adhere in a removable manner and an image forming apparatus. The image receiving sheet has a large number of concave portions accepting toner particles and a large number of convex portions protecting toner particles are formed on a surface of the image receiving sheet. The image forming apparatus has a sheet charging apparatus which charges the surface of the image receiving sheet to a polarity opposite to a charged polarity of toner particles, in advance of a transferring process.

Non-fixing type image receiving sheet, image forming method and image forming apparatus

An image forming apparatus is provided which forms images on both a concavo-convex sheet having a concavo-convex surface on which is formed many concavities capable of receiving toner and from which toner can be removed, and a general-purpose sheet which is not specially processed. The image forming apparatus has a first mode for forming an image on a general-purpose sheet, and a second mode for forming an image on a concavo-convex sheet. In the first mode, a general-purpose sheet receives a transferred toner image in the image forming region, and thereafter is guided to a fixing unit, where the toner is fixed on the sheet. In the second mode, a concavo-convex sheet receives a transferred toner image in the image forming region, and thereafter does not pass through the fixing unit but is guided to a convexity cleaning unit, where toner adhered to the convexities of the concavo-convex sheet during transfer is removed.

Image forming apparatus and method thereof

In order to achieve such effects that memories such as image memory due to untransferred residual toner can be sufficiently prevented, and good images can be obtained by suppressing base fogging and reduction of entire image density for a long term, an oscillating voltage composed of a DC ingredient and an oscillating ingredient is applied to a charging device for charging a photosensitive member, while the charging device is in a position facing an image forming region of the photosensitive member. While the charging device is in a position facing an image non-forming region of the photosensitive member, only a DC voltage is applied to the charging device for at least a predetermined time.

Image forming apparatus having rotatable charging brush with varying

An image forming apparatus having an insulated member disposed adjacent to a photosensitive member, a scanner exposing an image on the photosensitive member in a direction perpendicular to the direction of movement of the insulated member while voltage is applied between the photosensitive member and the insulated member so as to provide a charge on the insulated member surface corresponding to the optical exposure image. The exposure position exposed by the scanner is changed in the direction of movement of the image-bearing member for each scan.

Image forming apparatus

An image forming apparatus includes a charging rotary brush in contact with a photosensitive member, a laser beam irradiator to form an electrostatic latent image, a developing unit for developing the latent image into a visible image and collecting residual developer remaining on the surface of the photosensitive member after the visual image is transferred to a transfer material, and a power source unit for applying to the charging rotary brush an oscillating voltage fulfilling the requirement of:

Image forming apparatus having contact charger

An image forming apparatus having a rotatable photosensitive member a charging device for charging a surface of the photosensitive member prior to forming an electrophotographic latent image and a power source for applying a charge voltage which includes at least AC component to the charging device. The charging device includes a rotatable brush member which is formed by implanting piles formed by brush fibers on a base member and provided in contact with the photosensitive member. The photosensitive member and charging device and power source are provided to satisfy the following condition:

Image forming apparatus having a contact type charging device

An image forming apparatus includes a charging member in contact with a photosensitive member for applying a charging voltage at least containing an a.c. component, a laser beam irradiator having a polygon mirror to form an electrostatic latent image and a developing unit for developing the latent image into a visible image and collecting residual developer remaining on the surface of the photosensitive member after the visual image is transferred to a transfer material. The number of revolutions Fp(rps) of the irradiator polygon mirror, the frequency Fb(Hz) of the a.c. component to be applied to the contact charging unit and the system velocity Vp(cm/sec) have a correlation so determined as to meet the requirement of:

An image forming apparatus that includes a positioning device for selectively positioning a contact-charging member at a charging position where the contact-charging member contacts a photosensitive carrier at a first region or at a cleaning position where the contact-charging member contacts the carrier at a second region. A contact charger apparatus for charging a carrier for carrying an electrostatic latent image, said contact charger apparatus that includes a voltage source coupled to a contact charger for applying a voltage to said carrier; and a contact charger cleaner for changing a contact area between said contact charger and said carrier to effect cleaning of said contact charger.

Contact type charging device and image forming apparatus having the same

A cleaning method for a contact type charger in an cleanerless image forming apparatus. The method includes a step of switching bias voltages applied to the contact type charger and a develop/cleaning device from first level to a second level so as to release developer adhering to the contact type charger onto an image-bearing member as well as to collect a part of the developer moved onto the image-bearing member by the developing/cleaning device, and a step of switching the bias voltage from the second level to the first level so as to collect the rest of the developer released onto the image-bearing member by the develop/cleaning device.

Cleaning method for contact charging means in image forming apparatus

A contact charging device which charges a rotatable photoreceptor. The contact charging device has a support member provided adjacently to the photoreceptor, first and second films each one end portion of which is supported by the support member. Each free end portion of the first and second films is in contact with the surface of the photoreceptor. The second film is positioned on downstream side from the first film with respect to a rotational direction of the photoreceptor. In the above charging device, a resistance value of the first film is higher than a resistance value of the second film.

Contact charger and image forming apparatus provided with same

A contact charging device for charging an outer surface of an electrostatic latent image carrier in contact therewith which has a charging member at least partly in contact with the electrostatic latent image carrier, the portion of the charging member in contact with the electrostatic latent image carrier being formed by a layer containing a copolymer of an olefin-type vinyl monomer and a fluorine-contained monomer, and a power supply for applying a charging voltage to the charging member.

Charging device for charging outer surface of photosensitive member

A contact charger in an electrophotographic image forming apparatus for electrostatically charging a photosensitive, latent image support surface of a rotatably supported photosensitive drum in contact therewith. The contact charger comprises a generally elongated carrier and a charging member carried at a first side edge by the carrier. This charging member has a second side edge opposite to the first side edge which is held in sliding contact with the photosensitive surface over a predetermined contact distance. The charging member has a curved surface of a radius of curvature of 0.02 to 1.0 mm at a side edge portion thereof at which contact of the charging member with the photosensitive surface terminates. A power source for applying a voltage to the charging member is also employed.

Contact charger having a curved surface

The present invention discloses a developing device which includes a rotatably arranged photoreceptor, a rotatably disposed elastic roller confronting the photoreceptor, a cylindrically formed flexible member having a peripheral length longer than that of the elastic roller and loosely mounted thereover, and a positioning member to position the flexible member partly into contact with the photoreceptor, the positioning member including an elastic member to form a slack of the flexible member at a location confronting the photoreceptor for the flexible member to contact with the photoreceptor.

Monocomponent developing device

A monocomponent developing device for use in the electrophotographic image forming apparatus, which comprises a developing roller rotatably supported so as to confront a rotatably supported photoreceptor, a toner supply means for supplying toner onto the developing roller, a regulating member held in contact with a surface of the developing roller and operable to triboelectrically charge the toner, supplied onto the surface of the photoreceptor, while regulating the amount of the toner, and a coating film formed on at least a portion of a surface of the regulating member which is held in contact with the developing roller. The coating film has the same polarity in triboelectric series as that of the toner and is abradable after repetition of developing with a surface of the regulating member consequently exposed.

A developing device adjoins a rotatably arranged a photoreceptor, and is internally provided with a rotatably disposed developing roller confronting the photoreceptor, a cylindrically formed flexible film member having a peripheral length longer than that of the developing roller and loosely mounted thereover, a first member for forming a slack of the film member, for example, a regulating blade or a cleaning blade, a second member for controlling the position of the slack of the film member, for example, a magnet.

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Osaka, Japan

Masashi Yamamoto