Image forming apparatus and vehicle on which the image forming apparatus is mounted

• US 8,876,294 B2
• Filed: 09/11/2012
• Issued: 11/04/2014
• Est. Priority Date: 09/14/2011
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Saisho, Kenichiroh, Satoh, Hiroyuki
• Primary Examiner(s): Dowling, William C
• Application Number:
  US13/609,434
• Publication Number:
  US 20130063754A1
• Time in Patent Office: 784 Days
• Field of Search: 353 11- 14, 353/79, 353/28, 353/98, 353/99, 353/78, 359/630, 359/631, 359/633, 345/7
• US Class Current: 353/11
• CPC Class Codes: B23K 26/064 by means of optical elements, e.g. lenses, mirrors or prisms
• CPC Class Codes: B23K 26/0643 comprising mirrors
• CPC Class Codes: B23K 26/0648 comprising lenses
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0966 Cylindrical lenses cylindrical lenses per se G02B3/06
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 5/0257 creating an anisotropic diffusion characteristic, i.e. distributing output differently in two perpendicular axes
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors

Abstract

An image forming apparatus includes an optical scanning device including a light source element configured to radiate a light beam, an optical deflector configured to deflect the light beam two-dimensionally, and a target scanning surface that is transparent and having a two-dimensional image formed thereon by the light beam deflected from the optical deflector, and a projection optical system including a convex mirror and configured to enlarge and project the two-dimensional image on a target projection surface. The target projection surface includes a reflection surface of a half mirror. The half mirror is positioned outside of the image forming apparatus and configured to transmit a part of a light incident on the half mirror and reflect another part of the light incident on the half mirror.

Claims

1. An image forming apparatus comprising:

an optical scanning device including

a light source element configured to radiate a light beam,

an optical deflector configured to deflect the light beam two-dimensionally,

a concave mirror configured to deflect the light beam deflected by the optical deflector,

and

a target scanning surface that is transparent and having a two-dimensional image formed thereon by the light beam deflected from the optical deflector via the concave mirror; and

a projection optical system including a convex mirror and configured to enlarge and project the two-dimensional image on a target projection surface;

wherein the target projection surface includes a reflection surface of a half mirror,

wherein the half mirror is positioned outside of the image forming apparatus and configured to transmit a part of a light incident on the half mirror and reflect another part of the light incident on the half mirror,

wherein the optical deflector and the concave mirror are arranged, so that a sign of a deflection angle of the optical deflector and a sign of a deflection angle of the concave mirror become opposite to each other.

2. The image forming apparatus as claimed in claim 1, wherein the target scanning surface is a diffuser configured to diffuse an incident light in a traveling direction of the incident light.

3. The image forming apparatus as claimed in claim 2, wherein a cross section of the incident light diffused by the diffuser is an elliptical shape.

4. The image forming apparatus as claimed in claim 3,

wherein the diffuser is configured to form a virtual image by enlarging the two-dimensional image,

wherein the virtual image is formed in a predetermined position toward a side of the half mirror opposite to the reflection surface,

wherein a long axis direction of the elliptical shape matches a longitudinal direction of the virtual image.

5. The image forming apparatus as claimed in claim 1, wherein the convex mirror is positioned immediately in back of the target scanning surface.

6. The image forming apparatus as claimed in claim 1, wherein the target scanning surface is arranged in a position in which a normal line of the target scanning surface does not intersect the half mirror.

7. The image forming apparatus as claimed in claim 1,

further comprising:

a lens configured to guide the light beam from the light source element to the optical deflector,

wherein the lens is a meniscus lens having a concave surface side facing the optical deflector.

8. An image forming apparatus comprising:

an optical scanning device including

a light source element configured to radiate a light beam,

an optical deflector configured to deflect the light beam two-dimensionally,

a concave mirror configured to deflect the light beam deflected by the optical deflector, and

a target scanning surface that is transparent and having a two-dimensional image formed thereon by the light beam deflected from the optical deflector via the concave mirror;

a half mirror including a reflection surface and configured to transmit a part of a light incident on the half mirror and reflect another part of the light incident on the half mirror; and

a projection optical system including a convex mirror and configured to enlarge and project the two-dimensional image on the reflection surface,

wherein the optical deflector and the concave mirror are arranged, so that a sign of a deflection angle of the optical deflector and a sign of a deflection angle of the concave mirror become opposite to each other.

9. The image forming apparatus as claimed in claim 8,

wherein the reflection surface of the half mirror is a concave surface,

wherein a position of a deepest point of the concave surface is located toward the projection optical system more than a position of an optical center of the concave surface.

10. The image forming apparatus as claimed in claim 8,

further comprising:

a lens configured to guide the light beam from the light source element to the optical deflector,

wherein the lens is a meniscus lens having a concave surface side facing the optical deflector.

11. A vehicle comprising:

an image forming apparatus including

an optical scanning device including

a light source element configured to radiate a light beam,

an optical deflector configured to deflect the light beam two-dimensionally,

a concave mirror configured to deflect the light beam deflected by the optical deflector, and

a target scanning surface that is transparent and having a two-dimensional image formed thereon by the light beam deflected from the optical deflector via the concave mirror, the target projection surface including a reflection surface of a half mirror configured to transmit a part of a light incident on the half mirror and reflect another part of the light incident on the half mirror, and

a projection optical system including a convex mirror and configured to enlarge and project the two-dimensional image on a target projection surface; and

a front window that is integrated with the half mirror;

wherein the target scanning surface is configured to form a virtual image by enlarging the two-dimensional image,

wherein the virtual image is formed in a position in front of the reflection surface,

wherein the optical deflector and the concave mirror are arranged, so that a sign of a deflection angle of the optical deflector and a sign of a deflection angle of the concave mirror become opposite to each other.

12. The vehicle as claimed in claim 11,

wherein the image forming apparatus further includes a lens configured to guide the light beam from the light source element to the optical deflector,

wherein the lens is a meniscus lens having a concave surface side facing the optical deflector.