US 7,127,196 B2Granted

Electrophotographic photoreceptor, method for manufacturing the electrophotographic photoreceptor and image forming apparatus using the electrophotographic photoreceptor

AssigneeRicoh Company, Ltd.

InventorsHidetoshi Kami, Tatsuya Niimi, Akihiko Matsuyama, Eiji Kurimoto, Nozomu Tamoto

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Abstract

An image forming apparatus and a process cartridge having a photoreceptor including an electroconductive substrate; and a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler, wherein the content of the inorganic filler at a surface side of the photosensitive layer is greater than that at a bottom side of the photosensitive layer near the electroconductive substrate, and wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g·m31 2·24 h−1.

Claims12

Dependent claims

An image forming apparatus comprising:

a photoreceptor comprising,
an electroconductive substrate, and
a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler such that the photosensitive layer is a single mixture photosensitive layer that comprises the charge generation material, the charge transport material and the inorganic filler and the inorganic filler has a gradient-like concentration with a highest concentration at a surface side of the photosensitive layer farthest from said electroconductive substrate and a lowest concentration at a bottom side of the photosensitive layer near the electroconductive substrate,
wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g·m−2·24 h−1,
wherein the photosensitive layer is the outermost layer, and
wherein the single mixture photosensitive layer has a thickness of from 5 μm to 50 μm;
a charger configured to charge the photoreceptor;
an image irradiator configured to irradiate the photoreceptor with imagewise light to form an electrostatic latent image on the photoreceptor;
an image developer configured to develop the electrostatic latent image with a developer including a toner to form a toner image on the photoreceptor;
and
an image transfer device configured to transfer the toner image onto a receiving material.

8 more elements

An image forming apparatus comprising:

a photoreceptor comprising,
an electroconductive substrate, and
a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler such that the photosensitive layer is a functionally-separated photosensitive layer that comprises a charge generation layer including the charge generation material and formed overlying the electroconductive substrate, and a charge transport layer including the charge transport material and the inorganic filler and formed overlying the charge generation layer,
wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g m−2·24 h−1,
wherein the charge transport layer comprises a first charge transport layer not including the inorganic filler and a second charge transport layer including the inorganic filler and located on the first charge transport layer, and wherein the second charge transport layer is the outermost layer, and
wherein at least one of the first charge transport layer, the second charge transport layer and the charge transport layer has a charge mobility not less than 1.2×10−5 cm2/V·sec when measured at an electric field of 4×105V/cm, and wherein the charge mobility has an electric field dependency β not greater than 1.6×10−3, wherein the electric field dependency 13 is defined as follows:
β=log μ/E1/2
wherein log represents common logarithm;
p represents the mobility of the at least one of the first charge transport layer, the second charge transport layer and the charge transport layer in units of cm2/V·sec;
and B represents the electric field in units of V/cm;
a charger configured to charge the photoreceptor;
an image irradiator configured to irradiate the photoreceptor with imagewise light to form an electrostatic latent image on the photoreceptor;
an image developer configured to develop the electrostatic latent image with a developer including a toner to form a toner image on the photoreceptor;
and
an image transfer device configured to transfer the toner image onto a receiving material.

12 more elements

An image forming apparatus comprising:

a photoreceptor comprising,
an electroconductive substrate, and
a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler such that the photosensitive layer is a mixture photosensitive layer,
wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g·m−2·24 h−1,
wherein the mixture photosensitive layer comprises a first mixture photosensitive layer not including the inorganic filler, and a second mixture photosensitive layer including the inorganic filler and located on the first mixture photosensitive layer,
wherein the second mixture photosensitive layer is the outermost layer, and
wherein the first mixture photosensitive layer includes at least two charge generation compounds as the charge generation material and at least two charge transport compounds as the charge transport material, and wherein the second mixture photosensitive layer includes at least two charge generation compounds as the charge generation material and at least two charge transport compounds as the charge transport material, said at least two charge generation compounds and said at least two charge transport compounds included in the second mixture photosensitive layer are the same as or different from said at least two charge generation compounds and said at least two charge transport compounds included in the first mixture photosensitive layer, respectively;
a charger configured to charge the photoreceptor;
an image irradiator configured to irradiate the photoreceptor with imagewise light to form an electrostatic latent image on the photoreceptor;
an image developer configured to develop the electrostatic latent image with a developer including a toner to form a toner image on the photoreceptor;
and
an image transfer device configured to transfer the toner image onto a receiving material.

9 more elements

A process cartridge comprising:

a photoreceptor comprising,
an electroconductive substrate, and
a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler such that the photosensitive layer is a functionally-separated photosensitive layer that comprises a charge generation layer including the charge generation material and formed overlying the electroconductive substrate, and a charge transport layer including the charge transport material and the inorganic filler and formed overlying the charge generation layer,
wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g·m−224 h−1,
wherein the charge transport layer comprises a first charge transport layer not including the inorganic filler and a second charge transport layer including the inorganic filler and located on the first charge transport layer, and wherein the second charge transport layer is the outermost layer, and
wherein at least one of the first charge transport layer, the second charge transport layer and the charge transport layer has a charge mobility not less than 1.2×10−5 cm/V·sec when measured at an electric field of 4×105 V/cm, and wherein the charge mobility has an electric field dependency β not greater than 1.6×10−3, wherein the electric field dependency β is defined as follows:
β=log μ/E1/2
wherein log represents common logarithm;
μ represents the mobility of the at least one of the first charge transport layer, the second charge transport layer and the charge transport layer in units of cm2/V·sec;
and E represents the electric field in units of V/cm;
at least one of a charger configured to charge the photoreceptor;
an image irradiator configured to irradiate the photoreceptor with imagewise light to form an electrostatic latent image on the photoreceptor:
an image developer configured to develop the electrostatic latent image with a developer including a toner to form a toner image on the photoreceptor;
an image transfer device configured to transfer the toner image onto a receiving material;
a cleaner configured to clean a surface of the photoreceptor;
and
a discharger configured to discharge a residual charge of the photoreceptor.

14 more elements

A process cartridge comprising:

a photoreceptor comprising,
an electroconductive substrate, and
a photosensitive layer located overlying the electroconductive substrate and comprising a charge generation material, a charge transport material and an inorganic filler such that the photosensitive layer is a mixture photosensitive layer,
wherein an outermost layer of the photoreceptor has a water vapor permeability not greater than 50 g·m−2·24 h−,
wherein the mixture photosensitive layer comprises a first mixture photosensitive layer not including the inorganic filler, and a second mixture photosensitive layer including the inorganic filler and located on the first mixture photosensitive layer,
wherein the second mixture photosensitive layer is the outermost layer, and
wherein the first mixture photosensitive layer includes at least two charge generation compounds as the charge generation material and at least two charge transport compounds as the charge transport material, and wherein the second mixture photosensitive layer includes at least two charge generation compounds as the charge generation material and at least two charge transport compounds as the charge transport material, said at least two charge generation compounds and said at least two charge transport compounds included in the second mixture photosensitive layer are the same as or different from said at least two charge generation compounds and said at least two charge transport compounds included in the first mixture photosensitive layer, respectively;
at least one of a charger configured to charge the photoreceptor;
an image irradiator configured to irradiate the photoreceptor with imagewise light to form an electrostatic latent image on the photoreceptor:
an image developer configured to develop the electrostatic latent image with a developer including a toner to form a toner image on the photoreceptor;
an image transfer device configured to transfer the toner image onto a receiving material;
a cleaner configured to clean a surface of the photoreceptor;
and
a discharger configured to discharge a residual charge of the photoreceptor.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/017,731Filed 22 Dec 2004 · continuation
Priority: JP 2001-1345511 May 2001
Published: US 2005/0106482 A119 May 2005
Granted: 24 Oct 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G03G 5/14791
Macromolecular material: macromolecular compounds characterised by their structure, e.g. block polymers, reticulated polymers, or by their…
G03G 5/0217
Dielectric layers for electrography: inorganic components
G03G 5/0507
Inert supplements: inorganic compounds
G03G 5/14704
Cover layers: comprising inorganic material

Family

Application10/135,548Parent of this continuation · filed 1 May 2002
US 2005/0106482 A1Pre-grant publication · published 19 May 2005
US 2003/0113642 A1Published application
US 7,060,404 B2Related patent
US 7,127,196 B2This patent

From the US filing history. Foreign family members aren’t listed.