# US 12,372,921 B2 · Image forming apparatus

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- Number: US 12,372,921 B2
- Document ID: US12372921B2
- Status: Granted
- Kind: B2
- Application number: 18/540,300
- Filed: 2023-12-14
- Published: 2024-08-29
- Granted: 2025-07-29
- Earliest claimed: 2023-02-24
- Assignees: Oki Electric Industry Co., Ltd.
- Applicants: Oki Electric Industry Co., Ltd.
- Inventors: Kohei Minami
- Web page: https://patentgrep.com/patent/US12372921B2

## CPC

- G03G 21/206: {Conducting air through the machine, e.g. for cooling, filtering, removing gases like ozone}
- G03G 21/1628: {Clamshell type (G03G21/1638 takes precedence)}
- G03G 21/1647: {Mechanical connection means}
- G03G 21/1666: {for the exposure unit}
- G03G 2221/1636: for the exposure unit
- G03G 2221/1645: for conducting air through the machine, e.g. cooling
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

An image forming apparatus comprises an image forming unit including a photosensitive drum (image bearing body) 11, and an exposure unit including an exposure head that emits light to expose the photosensitive drum to form a latent image. The exposure unit has a duct unit extending in the X direction (longitudinal direction) of the image forming unit. The duct unit has an inlet opening through which air flows into the duct unit and an outlet opening through which the air is discharged from the duct unit. The exposure unit is provided pivotably about a pivot axis (virtual straight line) passing through the inlet opening.

## Claims

### Claim 1

An image forming apparatus comprising:
an image forming unit including an image bearing body; and
an exposure unit including an exposure portion that emits light to expose the image bearing body to form a latent image,
wherein the exposure unit has a duct unit extending in a longitudinal direction of the image forming unit,
wherein the duct unit has an inlet opening through which air flows into the duct unit and an outlet opening through which the air is discharged from the duct unit, and
wherein the exposure unit is provided pivotably about a virtual straight line passing through the inlet opening.

### Claim 2 (depends on 1)

The image forming apparatus according to claim 1,
wherein the duct unit has a first rib and a second rib that is farther from the inlet opening than the first rib, and
wherein an acute angle formed by the first rib with respect to the longitudinal direction is larger than an acute angle formed by the second rib with respect to the longitudinal direction.

### Claim 3 (depends on 1)

The image forming apparatus according to claim 1,
wherein the duct unit has a first rib, a second rib that is farther from the inlet opening than the first rib, and a third rib that is farther from the inlet opening than the second rib, and
wherein when a distance from an end of the first rib on the inlet opening side to an end of the second rib on the inlet opening side is defined as A1, and a distance from an end of the second rib on the inlet opening side to an end of the third rib on the inlet opening side is defined as A2, A1<A2 is established.

### Claim 4 (depends on 3)

The image forming apparatus according to claim 3,
wherein the duct unit has a fourth rib that is farther from the inlet opening than the third rib, and
wherein, when a distance from an end of the third rib on the inlet opening side to an end of the fourth rib on the inlet opening side is defined as A3, A2<A3 is satisfied.

### Claim 5 (depends on 1)

The image forming apparatus according to claim 1,
wherein the duct unit has a first rib and a second rib that is farther from the inlet opening than the first rib, and
wherein a distance L2 from the inlet opening to the second rib is longer than a distance L1 from the inlet opening to the first rib.

### Claim 6 (depends on 1)

The image forming apparatus according to claim 1,
wherein the duct unit comprises:
a first duct extending in the longitudinal direction,
a second duct that connects the inlet opening with the first duct, and
wherein the second duct extends from the inlet opening toward the outlet opening while being inclined with respect to the longitudinal direction.

### Claim 7 (depends on 6)

The image forming apparatus according to claim 6,
wherein the inlet opening is disposed on one end side of the duct unit in the longitudinal direction, and
wherein the second duct extends from the inlet opening toward the one end side of the outlet opening.

### Claim 8 (depends on 1)

The image forming apparatus according to claim 1,
wherein the inlet opening is disposed at a center of the duct unit in the longitudinal direction, and
wherein the duct unit has at least one rib that guides air having flowed in through the inlet opening in such a manner that the air spreads in the longitudinal direction.

### Claim 9 (depends on 1)

The image forming apparatus according to claim 1,
wherein the inlet opening is disposed on each of both ends of the duct unit in the longitudinal direction, and
wherein the duct unit has at least one rib that guides the air having flowed in through the inlet opening in such a manner that the air spreads toward a center of the duct unit in the longitudinal direction.

### Claim 10 (depends on 1)

The image forming apparatus according to claim 1, wherein the image forming unit has a heat sink at a position on which the air discharged from the outlet opening of the duct unit is blown.

### Claim 11 (depends on 1)

The image forming apparatus according to claim 1, wherein the exposure unit has a heat sink at a position on which the air discharged from the outlet opening of the duct unit is blown, the heat sink being in contact with the image forming unit.

### Claim 12 (depends on 1)

The image forming apparatus according to claim 1,
wherein the image forming unit comprises:
a developer bearing body bearing a developer to adhere to the image bearing body; and
a layer regulating unit including a layer regulating member that extends in the longitudinal direction and regulates a thickness of a layer of the developer on a surface of the developer bearing body, and
wherein the outlet opening of the duct unit is disposed to face the layer regulating unit.

### Claim 13 (depends on 12)

The image forming apparatus according to claim 12, wherein the layer regulating unit has a surface on which the air discharged from the outlet opening of the duct unit is blown, the surface having convexes or concaves.

### Claim 14 (depends on 1)

The image forming apparatus according to claim 1, further comprising:
a fan that feeds air to the inlet opening of the duct unit.

### Claim 15

An image forming apparatus comprising:
an image forming unit including an image bearing body; and
an exposure unit including an exposure portion that emits light to expose the image bearing body to form a latent image,
wherein the exposure unit has a duct unit extending in a longitudinal direction of the image forming unit,
wherein the duct unit has an inlet opening through which air flows into the duct unit and an outlet opening through which the air is discharged from the duct unit,
wherein the duct unit has a first rib and a second rib that is farther from the inlet opening than the first rib, and
wherein an acute angle formed by the first rib with respect to the longitudinal direction is larger than an acute angle formed by the second rib with respect to the longitudinal direction.