IP Library Granted Patent US 12693605
Granted Patent B2
US 12693605 · App. 19/048,964 · Granted Jul 28, 2026

Electrophotographic photoreceptor, process cartridge, and image forming apparatus

Inventors: Yuki Yonetoku (Kanagawa, JP); Hideya Katsuhara (Kanagawa, JP); Masaki Hirakata (Kanagawa, JP); Satoshi Mizoguchi (Kanagawa, JP); Takeshi Kawai (Kanagawa, JP); Yukie Hibi (Kanagawa, JP); Jiro Korenaga (Kanagawa, JP)
Assignee: FUJIFILM Business Innovation Corp.
G03G5/0696G03G5/0528G03G5/144G03G2215/00957G03G2215/00962G03G2221/183
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Quick Facts
Patent No.
US 12693605
App. No.
19/048,964
Granted
Jul 28, 2026
Kind
B2
Abstract

An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer that is provided on the conductive substrate and contains zinc oxide particles and a binder resin, a charge generation layer that is provided on the undercoat layer and contains titanium-containing organic pigment and a binder resin, and a charge transport layer that is provided on the charge generation layer, in which a film thickness of the undercoat layer is 15.0 μm or more and 30.0 μm or less, in a case where the film thickness of the undercoat layer is 22.0 μm or more and 30.0 μm or less, each of a proportion of a Ti concentration and a proportion of a Zn concentration with respect to a total of the Ti concentration and the Zn concentration in a region within +500 nm in a film thickness direction from an interface between the undercoat layer and the charge generation layer is 30% or more and 70% or less, and in a case where the film thickness of the undercoat layer is 15.0 μm or more and less than 22.0 μm, each of a proportion of a Ti concentration and a proportion of a Zn concentration with respect to a total of the Ti concentration and the Zn concentration in a region within +500 nm in a film thickness direction from an interface between the undercoat layer and the charge generation layer is 20% or more and 80% or less.

Claims (40)

1 . An electrophotographic photoreceptor comprising:

a conductive substrate;

an undercoat layer that is provided on the conductive substrate and contains zinc oxide particles and a binder resin;

a charge generation layer that is provided on the undercoat layer and contains titanium-containing organic pigment and a binder resin; and

a charge transport layer that is provided on the charge generation layer,

wherein a film thickness of the undercoat layer is 15.0 μm or more and 30.0 μm or less,

in a case where the film thickness of the undercoat layer is 22.0 μm or more and 30.0 μm or less, each of a proportion of a Ti concentration and a proportion of a Zn concentration with respect to a total of the Ti concentration and the Zn concentration in a region within ±500 nm in a film thickness direction from an interface between the undercoat layer and the charge generation layer is 30% or more and 70% or less, and

in a case where the film thickness of the undercoat layer is 15.0 μm or more and less than 22.0 μm, each of a proportion of a Ti concentration and a proportion of a Zn concentration with respect to a total of the Ti concentration and the Zn concentration in a region within ±500 nm in a film thickness direction from an interface between the undercoat layer and the charge generation layer is 20% or more and 80% or less.

2 . The electrophotographic photoreceptor according to claim 1 ,

wherein the titanium-containing organic pigment is titanyl phthalocyanine.

3 . A process cartridge comprising:

the electrophotographic photoreceptor according to claim 2 ,

wherein the process cartridge is attachable to and detachable from an image forming apparatus.

4 . An image forming apparatus comprising:

the electrophotographic photoreceptor according to claim 2 ;

a charging device that charges a surface of the electrophotographic photoreceptor;

an electrostatic charge image forming device that forms an electrostatic charge image on the charged surface of the electrophotographic photoreceptor;

a developing device that develops the electrostatic charge image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image; and

a transfer device that transfers the toner image to a surface of a recording medium.

5 . The electrophotographic photoreceptor according to claim 1 ,

wherein the film thickness of the undercoat layer is 15.0 μm or more and 25.0 μm or less, and

each of the proportion of the Ti concentration and the proportion of the Zn concentration with respect to the total of the Ti concentration and the Zn concentration in the region within ±500 nm in the film thickness direction from the interface between the undercoat layer and the charge generation layer is 40% or more and 60% or less.

6 . A process cartridge comprising:

the electrophotographic photoreceptor according to claim 5 ,

wherein the process cartridge is attachable to and detachable from an image forming apparatus.

7 . An image forming apparatus comprising:

the electrophotographic photoreceptor according to claim 5 ;

a charging device that charges a surface of the electrophotographic photoreceptor;

an electrostatic charge image forming device that forms an electrostatic charge image on the charged surface of the electrophotographic photoreceptor;

a developing device that develops the electrostatic charge image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image; and

a transfer device that transfers the toner image to a surface of a recording medium.

8 . A process cartridge comprising:

the electrophotographic photoreceptor according to claim 1 ,

wherein the process cartridge is attachable to and detachable from an image forming apparatus.

9 . An image forming apparatus comprising:

the electrophotographic photoreceptor according to claim 1 ;

a charging device that charges a surface of the electrophotographic photoreceptor;

an electrostatic charge image forming device that forms an electrostatic charge image on the charged surface of the electrophotographic photoreceptor;

a developing device that develops the electrostatic charge image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image; and

a transfer device that transfers the toner image to a surface of a recording medium.