Minolta Company, Ltd.

Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Konica-Minolta Holdings, Inc.

Keiko Momotani

Eiji Tabata

Akihito Ikegawa

Isao Doi

Naoki Yoshie

Masahiro Anno

Toshiya Natsuhara

Shigeo Uetake

Chiaki Yamada

Makiko Watanabe

Nofumi Mizumoto

Kenji Hayashi

Masahiko Matsuura

Kazuko Fukumoto

Miyuki Hotta

Yuya Kubo

Atsuto Hirai

Yuji Kamoda

Yukiko Uno

Yasuo Shirodai

Masaaki Oka

A transfer belt includes: an elastic layer, wherein the transfer belt is used to transfer a toner image onto a recording medium, the toner image being carried on a first main surface which is one of a pair of main exposed surfaces including the first main surface and a second main surface, when, using a lower block and an upper block, the transfer belt is placed on an upper surface of the lower block, a part of the transfer belt is interposed between a curved convex surface and a curved concave surface, and a pressed region reaches a pressing force of 200 [kPa] and is constantly pressed by the pressing force, if 'a' represents a maximum value of displacement of a measurement region, and 'b' represents displacement of the measurement region after convergence, E [&#x2212;] calculated by (a&#x2212;b)/b satisfies a condition of 0.2&#x2264;E&#x2264;3.

Transfer belt and image forming device

A transfer belt transfers a toner image carried on a first main surface to a recording medium. When the transfer belt is pressed by using a lower block provided with a hole and an upper block with pressurization force increased at a prescribed rate and thereafter kept constant, E [-] and t0 are curve-fitted to a function E=&#x3b1;&#xd7;exp(&#x2212;t0/&#x3c4;) defined by a time constant &#x3c4; [s] with respect to an amount of displacement of the transfer belt and a constant &#x3b1; [-], where E [-] is calculated as (a&#x2212;b)/b, a [&#x3bc;m] represents a maximum value of an amount of displacement of a measurement region, b [&#x3bc;m] represents an amount of displacement of the measurement region after converged, and t0 [s] represents a time period from start of pressurization until the maximum pressurization force, and time constant &#x3c4; satisfies a condition of 0.015&#x2264;&#x3c4;&#x2264;0.1.

Transfer belt and image formation apparatus

A transfer belt is configured to transfer a toner image carried on a first main surface of the transfer belt to a recording medium. When the transfer belt is pressed with pressure application three increased at a predetermined pressure application rate and is then pressed with certain pressure application force by using a lower block provided with a hole and an upper block, k[&#x3bc;m/s] satisfies 6&#x2264;k&#x2264;30, k[&#x3bc;m/s] being determined by (a&#x2212;b)/{2&#xd7;(t&#x2212;t)}, where a [&#x3bc;m/s] represents a maximum value of a displacement amount of a measurement region that is a portion of the first main surface corresponding to the hole, b [&#x3bc;m] represents a convergence value thereof, t[s] represents a time when the maximum value is observed, and t[s] represents a time when the displacement amount reaches (a+b)/2 again after the maximum value is observed.

Transfer belt and image forming apparatus

A liquid developer set of the present invention includes a first liquid developer including an insulating liquid and first toner particles and a second liquid developer including an insulating liquid and second toner particles, the first toner particles include carbon black and a first resin, the second toner particles include a coloring agent other than carbon black and a second resin, without including carbon black, the first resin and the second resin each include a hydrocarbon long chain which is a hydrocarbon group having a carbon number of 8 to 30, and a mass ratio of the hydrocarbon long chain to the first toner particles is higher than a mass ratio of the hydrocarbon long chain to the second toner particles.

Liquid developer set

A liquid developer contains an insulating liquid and toner particles dispersed in the insulating liquid. The toner particles have a resin and a coloring agent. The resin contains at least 10 mass % and at most 40 mass % of an aliphatic polyester resin and at least 60 mass % and at most 90 mass % of an aromatic polyester resin. The resin has an acid value not less than 20 mgKOH/g and not more than 100 mgKOH/g. A difference in acid value between the aliphatic polyester resin and the aromatic polyester resin is not less than 0 mgKOH/g and not more than 10 mgKOH/g.

Liquid developer

A liquid developer used for wet-type image forming apparatuses includes toner particles and an insulating liquid, the toner particles include a resin, a pigment, and a pigment dispersant, the pigment includes a pigment having an acid group, and the pigment dispersant is a basic polymer dispersant including units derived from &#x3b5;-caprolactone.

An image forming device includes a development member carrying a developer for forming a toner image at an image carrier, a cleaning member abutting against the development member for removing the developer remaining on the development member, a transportation member provided in contact with the development member for transporting the developer supplied to the development member, and a driving unit controlling driving of at least one of the transportation member and the development member. The driving unit executes preliminary driving of the development member and transportation member for a given time under a state where supply of the developer to the transportation member is stopped, prior to main driving in image formation. Consumption and/or degradation of the developer in preliminary driving is suppressed while strain at the development member or transportation member formed of a resilient member is removed.

Image forming device for suppressing developer consumption

This invention provides a developer concentration adjustment apparatus, a method for concentration adjustment, and an image forming apparatus, in which concentration adjustment is performed by use of a stirring load as a substitute characteristic of viscosity which represents a developer concentration, wherein a trouble of abnormality generation in toner concentration detection due to drying-adhesion of a residual developer on the stirrer is reduced. At the time of finishing the concentration adjustment, a concentration adjustment tank is made to be empty and the stirrer is cleaned by carrier liquid or a liquid developer having a concentration lower than a predetermined concentration. Alternatively, the stirrer is cleaned by empty-stirring operation not being put in a cleaning developer.

Developer concentration adjustment apparatus, method for adjusting developer concentration, and image forming apparatus using the same

Provided is a liquid development apparatus having a constitution in which liquid developer containing carrier liquid with toner dispersed therein is supplied from a liquid developer/cleaning liquid supply member on a pool forming member arranged facing to a supply roller so as to form a pool of the liquid developer, from which pool the liquid developer is supplied to the supply roller, wherein a liquid developer/cleaning liquid supply member supplies cleaning liquid on a pool forming member to form a suitable pooling portion of the cleaning liquid and the liquid developer remaining on the surface of the supply roller is removed and cleaned.

Liquid development apparatus and cleaning method that control either a gap between a pool forming member and a supply roller or a supply rate of a cleaning liquid

A liquid developer includes at least toner particles and an insulating liquid. The toner particles include a resin and a color material dispersed in the resin. 90 mass % or more of the insulating liquid is aliphatic saturated hydrocarbon having a carbon number of 11 to 16, and 20 to 60 mass % of the insulating liquid is aliphatic saturated hydrocarbon having a carbon number of 11 to 12.

An image forming apparatus includes a section for obtaining a property of a recording material; an adjusting section for adjusting a toner amount of a toner image formed by development depending on the property of the recording material; a charging section for charging the toner image before transfer; and a controlling section for adjusting a charging quantity by the charging section depending on the toner amount, where an appropriate quantity of charge depending on the toner amount is provided to the toner image before transfer to the recording material. Depending on the property of the recording material, an appropriate toner amount is transferred at a high transfer efficiency, and uniformity of a solid concentration is ensured.

Image forming apparatus

An image forming apparatus including a toner charge amount control portion for controlling the toner charge amount based on the property of a recording material; a recording material charging section for charging the surface of the recording material based on the toner charge amount controlled by the aforementioned toner charge amount control portion; and a recording media charge amount control portion for controlling the amount of charge on the surface of a recording material applied by the recording material charging section.

Image forming apparatus having toner charge amount control

A brush charger for static-charging a photosensitive drum by a contact method has a charging brush roller. The charging brush roller has a brush of a large number of conductive fibers, and the brush is wound around a conductive support spirally. The conductive fibers are 1.5 to 4 deniers in thickness D, are 2 mm in length L and are planted at a density not less than 150,000 filaments/inch, and the thickness D and the length L of the conductive fibers meet the condition, D&#x2267;0.71L&#x2212;1.61.

Brush charger for static-charging a photosensitive member and image forming apparatus

An image forming apparatus includes a first conductive member, a photoelectric transfer layer mounted on the first conductive member, a surface electrode mounted adjacent to the photoelectric transfer layer but away from the first conductive layer, a dielectric layer opposed to the surface electrode, a second conductive member mounted on one surface of the dielectric layer away from the photoelectric transfer layer. A first power supply is provided for applying a voltage V.sub.c between first and second conductive members and a second power supply is provided for applying a voltage V.sub.b between the surface electrode and the second conductive member. The image forming apparatus satisfies following relationship:

A contact charging device, in which a contact member for charging has a surface including a contact portion to be in contact with a charge receiving member as well as a charge contributing portion having a surface resistivity (.rho.s) of 1.times.10.sup.5 .OMEGA./.quadrature. or less. A maximum distance between the contributing portion and the charge receiving member is in a range from 5 .mu.m to 60 .mu.m. Alternatively, an electric power formed of a DC component is applied to the contact member to produce a potential difference in a range from 550 v to 750 v between the applied power and a potential at the surface of the charge receiving member before being charged by the electric power.

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Ibaraki, Japan

Keiko Momotani