Minolta Company, Ltd.

Minolta Camera Kabushiki Kaisha

Hidetoshi Miyamoto

Toshimitsu Fujiwara

Shuji Iino

Keyaki Yogome

Takaji Kurita

Masahiko Matsuura

Hiroshi Mizuno

Seishi Ojima

Masaharu Kanazawa

Masami Yamada

Junji Machida

Tetsumaru Fujita

Shuichi Nakagawa

Makoto Shimazoe

Yoshiko Yaoi

An image forming apparatus including first and second image forming portions, and a device for detecting a type of an image display medium, image formation by the first image forming portion being allowed when the medium type is a normal image display medium (PP), and image formation by the second image forming portion being allowed when the medium type is a reversible image display medium (TP). Another image forming apparatus including first and second image forming portions, and an image formation element setting switching device, image forming elements being set in a standard mode to a standard state for forming an image on a medium for the standard mode, and being switched in a non-standard mode to a non-standard state for forming an image on a medium for the non-standard mode.

Image forming apparatus capable of forming images on rewritable and reversible display media

A method of displaying information about an image forming apparatus comprising a first image forming portion for forming an image on a normal image display medium and a second image forming portion for forming an image on a reversible image display medium and capable of forming an image on the normal image display medium through the first image forming portion and of forming an image on the reversible image display medium through the second image forming portion, wherein the information about the image forming apparatus (information about the state of a predetermined item in the image forming apparatus) and (or) information about a setting state for image formation in the image forming apparatus) is displayed on a display device in the image forming apparatus and (or) a display device in an image information input apparatus transmitting image data to the image forming apparatus depending on the information, and an image forming apparatus capable of executing the method.

Image forming apparatus and method of displaying information about image forming apparatus

Image forming apparatus

A developing device includes a toner bearing member holding a toner on its surface for conveyance of the toner to a development region where the toner bearing member opposes an image bearing member via a predetermined gap therebetween; a regulating member pressed against the surface of the toner bearing member for regulation of the amount of toner conveyed to the development region; and a developing bias source for applying an alternating electric field between the toner bearing member and the image bearing member. The developing device features the use of the toner bearing member including a conductive substrate formed with an elastic layer, an intermediate layer and a surface layer on the surface thereof, respective volume resistances &rgr; and of which layers satisfy a condition &rgr; , the toner bearing member having an arithmetic average surface roughness in the range of 0.8 to 2.5 &mgr;m, and the use of the toner having a volume-average particle size of 3 to 8 &mgr;m.

Developing device

Reversible image display medium

A toner is formed on an image receiving sheet S. The image receiving sheet S has an irregular surface s &prime; provided with continuous groove-like concavities R for accommodating toner. The toner T is removably adhered to the concavities R of the image receiving sheet irregular surface s &prime; for forming the toner image. Ridges P extending along the continuous groove-like concavities R protect the toner T adhered to the concavities R. The toner image formation surface may be covered with a peelable protective sheet CF (CF&prime;). When the image receiving sheet S carrying the toner image is to be reused, the toner is separated and removed from the image receiving sheet, and the image receiving sheet and/or the toner after removal of the toner are reused.

Image forming method, image forming apparatus, toner removing device and image receiving sheet

An image forming apparatus including a first image forming portion for forming an image on a normal image display medium; a second image forming portion for forming an image on a reversible image display medium; and a medium type detecting device for detecting the type of the image display medium to be subjected to the image formation, wherein the image forming portion corresponding to the image display medium of the type detected by the medium type detecting device is allowed to perform the image formation when the medium type detecting device detects the image display medium of the same type as that selected by an operator, and inhibition of the image formation on the medium of the detected type, image formation on the image display medium of another type or discharge of the medium of the detected type without image formation is performed when the detected type is different from the selected type.

A reversible image display medium including two sheets; one or more developer accommodating cells formed between the two sheets, and each having a periphery surrounded by a partition wall; and dry developer contained in each of the cell(s), wherein the dry developer contains at least two kinds of frictionally chargeable dry developer particles having different chargeable polarities and different optical reflection densities. The image is displayed by forming a predetermined electrostatic field for each pixel in accordance with the image to be displayed and thereby moving the developer particles in a frictionally charged state. The image formed on the reversible image display medium can be erased, e.g., by an image erasing device.

Reversible image display medium and image display method

Image display method, image forming apparatus and reversible image display medium

(1) Electrophotographic liquid developer comprising electrically insulating medium liquid and toner dispersed in the medium liquid, wherein the toner has a melt viscosity (.eta.) in a range from 2.times.10.sup.2 poises to 1.times.10.sup.5 poises at 100.degree. C. in a dry state, and has a glass transition temperature of 20.degree. C. or more. (2) Electrophotographic liquid developer comprising electrically insulating medium liquid and toner dispersed in the medium liquid, wherein the toner contains binder resin exhibiting at least one peak in each of ranges of a molecular weight lower than 5000 and of a molecular weight of 5000 or more when detected by a gel permeation chromatography (GPC). (3) An image forming apparatus comprising an electrostatic latent image carrier for forming an electrostatic latent image; a liquid developing device developing the electrostatic latent image formed on the electrostatic latent image carrier into a visible toner image with liquid developer; an intermediate transfer member carrying the toner image transferred thereto from the electrostatic latent image carrier for further transferring the transferred toner image to a record member; and a heating device for heating the intermediate transfer member, wherein the liquid developing device develops the electrostatic latent image with the liquid developer of the above (1) or (2).

Electrophotographic liquid developer and image forming apparatus

A liquid developer set formed of a liquid developer used for developing an electrostatic latent image and containing a carrier liquid, a charge director and toner, a first liquid, which is obtained by removing a solid component from the liquid developer, having a charge director concentration C1 and a conductivity E1; a concentrated liquid developer containing the carrier liquid, the charge director and the toner in a higher concentration than the toner concentration of the liquid developer, a second liquid, which is obtained by removing a solid component from the concentrated liquid developer, having a charge director concentration C2 and a conductivity E2 substantially equal to the concentration C1 and the conductivity E1, respectively; and a diluent containing the carrier liquid and the charge director, and having a charge director concentration C3 and a conductivity E3 substantially equal to the concentration C1 and the conductivity E1, respectively. The concentrated liquid developer, the diluent and a method of manufacturing the diluent.

Liquid developer set, concentrated liquid developer, diluent and method

Toner includes binder resin having an acid value in a range from 10 mgKOH/g to 100 mgKOH/g; and at least one kind of compound selected from among Color Index Pigment Yellow 180 and derivatives thereof. A liquid developer includes the toner and carrier liquid. Toner includes binder resin having a weight average molecular weight (Mw) in a range from 3000 to 10000; and at least one kind of compound selected from among Color Index Pigment Yellow 180 and derivatives thereof. A liquid developer includes the toner and carrier liquid.

Toner and liquid developer

The invention provides the following liquid developers (1)-(5). (1) A liquid developer including a carrier liquid having an aniline point of 80.degree. C. to 100.degree. C.; and at least one compound selected from among Color Index Pigment Yellow 180, Color Index Solvent Yellow 162 and derivatives of these. (2) A liquid developer including a carrier liquid having an aniline point of 80.degree. C. to 100.degree. C.; toner; and at least one compound selected from among salicylic acid metal salt and derivatives thereof. (3) A liquid developer including a carrier liquid having an aniline point of 80.degree. C. to 100.degree. C.; toner; and at least one compound selected from among borate-containing compound and derivatives thereof. (4) A liquid developer including a carrier liquid; at least one compound selected from among an oil-soluble ionic surfactant having alkyl group(s) of at least 20 carbon atoms, and a copolymer of a monomer having a nitrogen-containing group and a long-chain (meth)acrylate; and toner containing at least one compound selected from among Color Index Pigment Yellow 180, Color Index Solvent Yellow 162 and derivatives of these. (5) A liquid developer including a carrier liquid; and toner containing Color Index Pigment Yellow 180 and having volume average particle size of 0.5 .mu.m to 5 .mu.m.

Liquid developer

A liquid developer having a superior sedimentation characteristic and floating characteristic and an image forming apparatus using said liquid developer, wherein said liquid developer comprising toner dispersed in liquid medium and the difference in specific gravity between said toner and said liquid medium is at or lower than a prescribed level.

Liquid developer and image forming apparatus

A liquid developer for electrophotography using a polyester resin as a toner binder resin which is suitable for high-speed systems and has excellent stability over time is disclosed. The invention is a novel liquid developer for electrophotography having colored particles dispersed in an electrically insulated fluid medium. The liquid developer includes an oil-soluble ionic surface active agent as a charge controller. According to one embodiment, the colored particles include a binder resin having an acid value of 40 mgKOH/g or higher but less than or equal to 100 mgKOH/g. According to another embodiment, the colored particles include a binder resin having a glass transition temperature Tg of 35.degree. C. or higher but less than or equal to 65.degree. C.

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Takatsuki, Japan

Hidetoshi Miyamoto