# US 2024/0201482 A1 · Optical scanning device and image forming apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2024/0201482 A1
- Document ID: US20240201482A1
- Status: Published application
- Kind: A1
- Application number: 18/382,645
- Filed: 2023-10-23
- Published: 2024-06-20
- Earliest claimed: 2022-12-16
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Sharp Kabushiki Kaisha
- Inventors: KENZO OHKUBO; TAKAYUKI OHNO
- Web page: https://patentgrep.com/patent/US20240201482A1

## CPC

- G02B 26/123: {Multibeam scanners, e.g. using multiple light sources or beam splitters}
- G02B 26/105: {with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence)}
- G02B 26/124: {Details of the optical system between the light source and the polygonal mirror (G02B26/123, G02B26/127 take precedence)}
- G03G 15/0435: {by introducing an optical element in the optical path, e.g. a filter}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY

## Abstract

A rotational direction of a multi-beam light source around a rotational axis is made different to a side where a sub-scanning width in a sub-scanning direction of a plurality of light beams is made smaller between a case of one-side incidence in which the plurality of light beams are made incident to the rotary polygon mirror from either one of sides in the rotary axis direction of a rotary polygon mirror and a case of the other-side incidence in which the plurality of light beams are made incident to the rotary polygon mirror from the other side.

## Claims

### Claim 1

An optical scanning device comprising a multi-beam light source having a plurality of light emitting elements aligned in parallel in a predetermined linear direction, a rotary polygon mirror, and a reflection mirror along a rotary axis direction of the rotary polygon mirror, a plurality of light beams emitted from each of the plurality of light emitting elements being reflected by the reflection mirror, the plurality of light beams reflected by the reflection mirror being made incident to the rotary polygon mirror, and the plurality of light beams reflected by the rotary polygon mirror being emitted toward an object to be scanned, wherein the multi-beam light source is capable of rotational adjustment around a rotational axis along an emission direction of the plurality of light beams, and a rotational direction of the multi-beam light source around the rotational axis is made different to a side where a sub-scanning width in a sub-scanning direction of the plurality of light beams is made smaller between a case of one-side incidence in which the plurality of light beams are made incident to the rotary polygon mirror from either one of sides in the rotary axis direction of the rotary polygon mirror and a case of the other-side incidence in which the plurality of light beams are made incident to the rotary polygon mirror from the other side.

### Claim 2 (depends on 1)

The optical scanning device according to claim 1, further comprising a collimator lens provided between the multi-beam light source and the reflection mirror, wherein, assuming that the rotary axis direction of the rotary polygon mirror as an up-down direction, when the plurality of light beams are made incident from lower right and are reflected from a mirror surface of the reflection mirror toward upper left, when viewed from a mirror surface side of the reflection mirror, in the multi-beam light source, when viewed from a side opposite to the emission direction, the plurality of light emitting elements aligned in parallel in the linear direction are rotationally adjusted to positions rotated by less than 90 degrees in a clockwise direction around the rotational axis from a predetermined reference adjustment position along the up-down direction.

### Claim 3 (depends on 1)

The optical scanning device according to claim 1, further comprising a collimator lens provided between the multi-beam light source and the reflection mirror, wherein, assuming that the rotary axis direction of the rotary polygon mirror as an up-down direction, when the plurality of light beams are made incident from upper right and are reflected from a mirror surface of the reflection mirror toward lower left, when viewed from a mirror surface side of the reflection mirror, in the multi-beam light source, when viewed from a side opposite to the emission direction, the plurality of light emitting elements aligned in parallel in the linear direction are rotationally adjusted to positions rotated by less than 90 degrees in a counterclockwise direction around the rotational axis from a predetermined reference adjustment position along the up-down direction.

### Claim 4 (depends on 1)

The optical scanning device according to claim 1, wherein an optical path pattern formed by combining an optical path of each of the light beams incident to a reflection surface of the rotary polygon mirror is asymmetric with respect to a reference virtual line passing through the reflection surface and orthogonal to the rotary axis of the rotary polygon mirror when viewed from a normal direction of the reflection surface of the rotary polygon mirror.

### Claim 5 (depends on 1)

The optical scanning device according to claim 1, further comprising a cylindrical lens that refracts the plurality of light beams and forms an image on a reflection surface of the rotary polygon mirror, and an aperture that is disposed between the cylindrical lens and the rotary polygon mirror and closer to the rotary polygon mirror than the cylindrical lens and narrows the light beams incident to the reflection surface of the rotary polygon mirror.

### Claim 6 (depends on 1)

An image forming apparatus comprising the optical scanning device according to claim 1.