LIGHT SCANNING UNIT AND IMAGE FORMING APPARATUS EMPLOYING THE SAME

• US 20150109398A1
• Filed: 06/18/2014
• Published: 04/23/2015
• Est. Priority Date: 10/17/2013
• Status: Active Grant

• Current Assignee: HP Printing Korea Co., Ltd. (HP Inc.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PARK, Chul-hyun, Lee, Han-sung
• Granted Patent: US 9,296,221 B2
• Time in Patent Office: Days
• US Class Current: 347/137
• CPC Class Codes: B41J 2/447 using arrays of radiation sources B41J2/475 takes precedence
• CPC Class Codes: B41J 2/471 using dot sequential main scanning by means of a light deflector, e.g. a rotating polygonal mirror
• CPC Class Codes: B41J 2/473 using multiple light beams, wavelengths or colours
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/123 Multibeam scanners, e.g. using multiple light sources or beam splitters
• CPC Class Codes: G02B 26/124 Details of the optical system between the light source and the polygonal mirror G02B26/123, G02B26/127 take precedence
• CPC Class Codes: G03G 15/043 with means for controlling illumination or exposure G03G15/041 takes precedence

Abstract

A light scanning unit includes a light source unit emitting a light beam according to an image signal, a light deflector scanning the light beam that is deflectively emitted by the light source unit, a housing having a side portion where the light source unit is provided and a base surface on which the light deflector is provided, and a deformation prevention member connecting opposite sides of the housing across an upper side of the base surface. The light scanning unit is employed by an image forming apparatus.

Claims

1. A light scanning unit comprising:

a light source to emit a light beam according to an image signal;

a light deflector to deflectively scan the light beam that is emitted by the light source;

a housing having a first side wall where the light source is provided and a base surface on which the light deflector is provided; and

a deformation prevention member to connect opposite sides of the housing across an upper side of the base surface.

2. The light scanning unit of claim 1, wherein the deformation prevention member is formed of a material having a thermal expansion coefficient that is lower than that of a material of the housing.

3. The light scanning unit of claim 2, wherein the housing is formed of plastic resin and the deformation prevention member is formed of metal or plastic resin.

4. The light scanning unit of claim 1, wherein the housing has a second side wall arranged facing the first side wall with the light deflector interposed between the first and second side walls, and the deformation prevention member connects the first and second side walls.

5. The light scanning unit of claim 4, wherein a portion of the deformation prevention member that is connected to the first side wall is an area where the light source is provided or an area adjacent to the area where the light source is provided.

6. The light scanning unit of claim 1, wherein the deformation prevention member has a form of a long bar or a plate.

7. The light scanning unit of claim 1, wherein one or a plurality of the deformation prevention members are provided

8. The light scanning unit of claim 1, wherein the deformation prevention member is disposed to be higher than an installation height of a light source of the light source.

9. The light scanning unit of claim 1, wherein the deformation prevention member has a strength reinforcement structure.

10. The light scanning unit of claim 9, wherein the strength reinforcement structure comprises at least one of a bent portion on a cross-sectional surface of the deformation prevention member, an embossment formed on a surface of the deformation prevention member, and a rib provided on a surface of the deformation prevention member.

11. The light scanning unit of claim 1, wherein the housing further comprises a cover disposed above the deformation prevention member and the cover comprises a heat dissipation hole provided adjacent to a position where the deformation prevention member is disposed.

12. The light scanning unit of claim 1, wherein the light source comprises a plurality of light sources and the plurality of light sources are arranged at one side wall of the housing.

13. The light scanning unit of claim 12, wherein the light source further comprises an integrated light source holder that fixes the plurality of light sources to the housing.

14. The light scanning unit of claim 13, wherein the light source holder is integrally formed with the housing.

15. The light scanning unit of claim 13, wherein the light source further comprises a circuit board where the plurality of light sources are mounted.

16. The light scanning unit of claim 12, wherein light beams emitted by the plurality of light sources are obliquely incident on the light deflector with respect to a sub-scanning direction.

17. The light scanning unit of claim 1, wherein the light source comprises first to fourth light sources that emit first to fourth light beams, and the light deflector deflectively scans the first and second light beams on one deflection surface and the third and fourth light beams on a deflection surface that is different from the one deflection surface.

18. The light scanning unit of claim 1, further comprising an incident optical system that is arranged between the light source and the light deflector.

19. The light scanning unit of claim 18, wherein the incident optical system comprises at least one of a collimator lens that shapes a light beam emitted by the light source unit into a parallel luminous flux and a cylindrical lens that focuses the light beam, which is emitted by the light source, on a deflection surface of the light deflector in a sub-scanning direction.

20. The light scanning unit of claim 1, further comprising an imaging optical system for forming on a surface to be scanned an image of a light beam that is deflectively scanned by the light deflector.

21. The light scanning unit of claim 20, wherein the imaging optical system comprises one or more scanning lenses for forming an image of luminous flux at a constant velocity.

22. An electrophotographic image forming apparatus comprising:

an image receptor;

a light scanner to form an electrostatic latent image by scanning a light beam onto a surface to be scanned of the image receptor; and

a developer to develop the electrostatic latent image formed on the image receptor by supplying toner to the electrostatic latent image,

wherein the light scanner comprises;

a light source to emit a light beam according to an image signal;

a light deflector to deflectively scan the light beam that is emitted by the light source;

a housing having a side portion where the light source is provided and a base surface on which the light deflector is provided; and

a deformation prevention member to connect opposite sides of the housing across an upper side of the base surface.

23. A laser scanner comprising:

a housing having a first sidewall, which is configured to receive a light source, and a second sidewall arranged to face the first sidewall; and

a deformation prevention member to connect the first side wall to the second sidewall,

wherein the deformation prevention member is formed of a material having a thermal expansion coefficient that is lower than that of a material of the housing.