Optical scanning system

• US 5,546,216 A
• Filed: 08/26/1994
• Issued: 08/13/1996
• Est. Priority Date: 08/26/1993
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Suzuki, Seizo
• Primary Examiner(s): Phan, James
• Application Number:
  US08/296,433
• Time in Patent Office: 718 Days
• Field of Search: 359/216-219, 359/707, 359/434, 358/296, 358/474, 347/259-261, 347/258, 250/234-236
• US Class Current: 359/216.1
• CPC Class Codes: G02B 26/12 using multifaceted mirrors
• 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

Abstract

An optical scanning system which converges light flux on a photoconductive member by an optical scanning lens after the light flux from a light source is coupled by a coupling lens (a condensing lens) and reflected by a polygonal mirror. The optical scanning system includes an area light emission source, the area light emission source and the photoconductive member being provided with geometrically-optically conjugate relations.

Claims

1. An optical scanning system comprising:

a point light source;

a coupling lens which couples light flux from said point light source;

an optical scanning lens which converges the light flux on a photoconductive member via a polygonal mirror after said coupling lens couples said light flux;

a diffusion board; and

an aperture which is provided near said diffusion board, the diffusion board being formed between the aperture and the coupling lens, wherein after said coupling lens couples light flux from said point light source, the light flux is directed through said diffusion board, and wherein said aperture and said photoconductive member are provided to have substantially geometrically-optically conjugate relations, thereby a shape of the light flux converged on the photoconductive member is in a shape of the aperture.

2. An optical scanning system according to claim 1, further comprising:

a relay lens being provided between said diffusion board and said optical scanning lens to reduce a loss of quantity of light.

3. An optical scanning system according to claim 1, further comprising:

a beam spot having a rectangular intensity distribution on the photoconductive member created by the optical scanning lens.

4. An optical scanning system comprising:

a point light source;

a coupling lens which couples light flux from said point light source;

an optical scanning lens which converges the light flux on a photoconductive member via a polygonal mirror after said coupling lens couples said light flux;

a diffusion board; and

an aperture which is provided near said diffusion board, the diffusion board being formed between the aperture and the coupling lens, wherein after said coupling lens couples light flux from said point light source, the light flux is directed through said diffusion board, and wherein said aperture and said photoconductive member are provided to have substantially geometrically-optically conjugate relations;

a relay lens being provided between said diffusion board and said optical scanning lens to reduce a loss of quantity of light;

wherein said relay lens further comprises;

a retro-focus system including a concave lens group and a convex lens group.

5. An optical scanning system according to claim 4, further comprising:

a beam spot having a rectangular intensity distribution on the photoconductive member created by the optical scanning lens.