# US 2017/0255113 A1 · Image forming apparatus and image forming method

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- Number: US 2017/0255113 A1
- Document ID: US20170255113A1
- Status: Published application
- Kind: A1
- Application number: 15/230,609
- Filed: 2016-08-08
- Published: 2017-09-07
- Earliest claimed: 2016-03-02
- Assignees: Fuji Xerox Co., Ltd.
- Applicants: Fuji Xerox Co., Ltd.
- Inventors: Masahiko MIYAMOTO; Shigeto HASHIBA
- Web page: https://patentgrep.com/patent/US20170255113A1

## CPC

- G03G 15/75: {Details relating to xerographic drum, band or plate, e.g. replacing, testing (electrographic recording members per se G03G5/00)}
- G03G 5/0517: {comprising one or more cyclic groups consisting of carbon-atoms only}
- G03G 5/061443: {benzidine}
- G03G 5/061473: {plural alkenyl groups linked directly to the same aryl group}
- G03G 5/0672: {containing two or more methine or polymethine groups}
- G03G 5/0696: {Phthalocyanines}
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming apparatus includes an electrophotographic photoreceptor that includes a photosensitive layer that contains a charge generation material, a charge transport material, and a binder resin; a charging unit; an electrostatic latent image forming unit; a developing unit; and a transfer unit. A charge amount ΔQ(μC/m2), which is accumulated in the photosensitive layer by exposure conducted by using the electrostatic latent image forming unit, per unit area of a surface of the electrophotographic photoreceptor, a charge potential VH(V) after the surface of the electrophotographic photoreceptor is charged by using the charging unit, and an exposure potential VL(V) of a portion of the surface of the electrophotographic photoreceptor exposed by using the electrostatic latent image forming unit satisfy the following formula: 20(V·m2/μC)≦[VH−VL](V)/ΔQ(μC/m2)≦60(V·m2/μC)

## Claims

### Claim 1

An image forming apparatus comprising:
an electrophotographic photoreceptor that includes a photosensitive layer that contains a charge generation material, a charge transport material, and a binder resin;
a charging unit that charges a surface of the electrophotographic photoreceptor;
an electrostatic latent image forming unit that forms an electrostatic latent image by exposing the charged surface of the electrophotographic photoreceptor;
a developing unit that develops the electrostatic latent image on the surface of the electrophotographic photoreceptor with a developer that contains a toner so as to form a toner image; and
a transfer unit that transfers the toner image onto a surface of a recording medium,
wherein a charge amount ΔQ(μC/m2), which is accumulated in the photosensitive layer by exposure conducted by using the electrostatic latent image forming unit, per unit area of the surface of the electrophotographic photoreceptor, a charge potential VH(V) after the surface of the electrophotographic photoreceptor is charged by using the charging unit, and an exposure potential VL(V) of a portion of the surface of the electrophotographic photoreceptor exposed by using the electrostatic latent image forming unit satisfy Formula (1):
20(V·m2/μC)≦[VH−VL](V)/ΔQ(μC/m2)≦60(V·m2/μC) Formula (1)

### Claim 2 (depends on 1)

The image forming apparatus according to claim 1, wherein [VH−VL](V)/ΔQ(μC/m2) is 25(V·m2/μC) or more and 55(V·m2/μC) or less.

### Claim 3 (depends on 1)

The image forming apparatus according to claim 1, wherein [VH−VL](V)/ΔQ(μC/m2) is 35(V·m2/μC) or more and 50(V·m2/μC) or less.

### Claim 4 (depends on 1)

The image forming apparatus according to claim 1, wherein the charge transport material contained in the photosensitive layer includes a compound represented by Formula (CT1) below and a compound represented by Formula (CT2) below:
(In Formula (CT1), RC11, RC12, RC13, RC14, RC15, and RC16 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, or an aryl group having from 6 to 30 carbon atoms; adjacent two substituents may bond to each other to form a hydrocarbon ring structure; and n and m each independently represent 0, 1, or 2.);
(In Formula (CT2), RC21, RC22, and RC23 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atoms, or an aryl group having from 6 to 10 carbon atoms.)

### Claim 5 (depends on 1)

The image forming apparatus according to claim 1, wherein the charge generation material contained in the photosensitive layer includes hydroxygallium phthalocyanine.

### Claim 6 (depends on 1)

The image forming apparatus according to claim 1, wherein the photosensitive layer includes a charge generation layer that contains hydroxygallium phthalocyanine as the charge generation material and a charge transport layer that contains a compound represented by Formula (CT1) below and a compound represented by Formula (CT2) below as the charge transport material:
(In Formula (CT1), RC11, RC12, RC13, RC14, RC15, and RC16 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, or an aryl group having from 6 to 30 carbon atoms; adjacent two substituents may bond to each other to form a hydrocarbon ring structure; and n and m each independently represent 0, 1, or 2.);
(In Formula (CT2), RC21, RC22, and RC23 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atoms, or an aryl group having from 6 to 10 carbon atoms.)

### Claim 7 (depends on 1)

The image forming apparatus according to claim 1, wherein the photosensitive layer contains a hindered phenol antioxidant.

### Claim 8

An image forming method comprising:
charging a surface of an electrophotographic photoreceptor that includes a photosensitive layer that contains a charge generation material, a charge transport material, and a binder resin;
forming an electrostatic latent image by exposing the charged surface of the electrophotographic photoreceptor;
developing the electrostatic latent image on the surface of the electrophotographic photoreceptor with a developer that contains a toner so as to form a toner image; and
transferring the toner image onto a surface of a recording medium,
wherein a charge amount ΔQ(μC/m2), which is accumulated in the photosensitive layer by exposure conducted in the forming of the electrostatic latent image, per unit area of the surface of the electrophotographic photoreceptor, a charge potential VH(V) after the surface of the electrophotographic photoreceptor is charged in the charging of the surface of the electrophotographic photoreceptor, and an exposure potential VL(V) of a portion of the surface of the electrophotographic photoreceptor exposed in the forming of the electrostatic latent image satisfy Formula (1):
20(V·m2/μC)≦[VH−VL](V)/ΔQ(μC/m2)≦60(V·m2/μC) Formula (1)

### Claim 9 (depends on 8)

The image forming method according to claim 8, wherein [VH−VL](V)/ΔQ(μC/m2) is 25(V·m2/μC) or more and 55(V·m2/μC) or less.

### Claim 10 (depends on 8)

The image forming method according to claim 8, wherein [VH−VL](V)/ΔQ(μC/m2) is 35(V·m2/μC) or more and 50(V·m2/μC) or less.

### Claim 11 (depends on 8)

The image forming method according to claim 8, wherein the charge transport material contained in the photosensitive layer includes a compound represented by Formula (CT1) below and a compound represented by Formula (CT2) below:
(In Formula (CT1), RC11, RC12, RC13, RC14, RC15, and RC16 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, or an aryl group having from 6 to 30 carbon atoms; adjacent two substituents may bond to each other to form a hydrocarbon ring structure; and n and m each independently represent 0, 1, or 2.);
(In Formula (CT2), RC21, RC22, and RC23 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atoms, or an aryl group having from 6 to 10 carbon atoms.)

### Claim 12 (depends on 8)

The image forming method according to claim 8, wherein the charge generation material contained in the photosensitive layer includes hydroxygallium phthalocyanine.

### Claim 13 (depends on 8)

The image forming method according to claim 8, wherein the photosensitive layer includes a charge generation layer that contains hydroxygallium phthalocyanine as the charge generation material and a charge transport layer that contains a compound represented by Formula (CT1) below and a compound represented by Formula (CT2) below as the charge transport material:
(In Formula (CT1), RC11, RC12, RC13, RC14, RC15, and RC16 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, or an aryl group having from 6 to 30 carbon atoms; adjacent two substituents may bond to each other to form a hydrocarbon ring structure; and n and m each independently represent 0, 1, or 2.);
(In Formula (CT2), RC21, RC22, and RC23 each independently represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 10 carbon atoms, an alkoxy group having from 1 to 10 carbon atoms, or an aryl group having from 6 to 10 carbon atoms.)

### Claim 14 (depends on 8)

The image forming method according to claim 8, wherein the photosensitive layer contains a hindered phenol antioxidant.