Multifocal lens array and three-dimensional stereoscopic image display apparatus

• US 7,791,805 B2
• Filed: 02/09/2007
• Issued: 09/07/2010
• Est. Priority Date: 02/09/2006
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Device Technology Company Limited (Fuji Electric Systems Company Limited)
• Inventors: Yokosawa, Teruhisa
• Primary Examiner(s): Sugarman; Scott J
• Assistant Examiner(s): PINKNEY, DAWAYNE
• Application Number:
  US11/673,176
• Publication Number:
  US 20070188862A1
• Time in Patent Office: 1,306 Days
• Field of Search: 359454-457, 359/463, 359618-626
• US Class Current: 359/626
• CPC Class Codes: G02B 3/0043 Inhomogeneous or irregular arrays, e.g. varying shape, size, height
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 30/54 the 3D volume being generated by moving a 2D surface, e.g. by vibrating or rotating the 2D surface
• CPC Class Codes: H04N 13/395 with depth sampling, i.e. the volume being constructed from a stack or sequence of 2D image planes

Abstract

A multifocal lens array and a three-dimensional stereoscopic image display apparatus, which has a low cost, simple structure. A two-dimensional image is displayed on a display apparatus and is incident on a multifocal lens array. The array includes a plurality of lenses arranged on a planar surface, respective focal distances of the lenses being selected so that a focal point-containing surface is formed at a surface inclined relative to the planar surface. A stereoscopic diffusing panel including six transparent panels is disposed at the focal point-containing surface, and is moved periodically in a depth direction, so that sectional images of a three-dimensional stereoscopic image are rendered on the stereoscopic diffusing panel through image light from the apparatus, and hence a person viewing light reflected from the stereoscopic diffusing panel can see the three-dimensional stereoscopic image due to an after-image effect.

Claims

1. A multifocal lens array, comprising:

a planar surface;

a plurality of lenses arranged on said planar surface and having respective focal distances; and

a stereoscopic diffusing surface inclined relative to said planar surface,

wherein said respective focal distances of said plurality of lenses are selected so that a focal point-containing surface is formed at said surface inclined relative to said planar surface wherein said focal point-containing surface is a curved surface, wherein said curved surface has a shape including part of a curved surface represented by X=r_x cos θ

, Y=r_x sin θ

, Z=a_xθ

in terms of polar coordinates, where X, Y and Z are three-dimensional rectangular coordinate system coordinate axes, r is a radius, θ

is an angle, and a is a constant.

2. The multifocal lens array according to claim 1, wherein each lens of said plurality of lenses has a thickness of not more than 2 mm.

3. The multifocal lens array according to claim 1, wherein the stereoscopic diffusing surface is provided by a stereoscopic diffusing panel that comprises a plurality of films each comprising a planar surface arranged parallel to one another at equal intervals so that each of the films is positioned obliquely relative to the planar surface, and that is movably supported directly above the planar surface in an optical path from the planar surface.

4. The multifocal lens array according to claim 1, wherein the plurality of lenses is a plurality of discrete lenses arranged on said planar surface in an array and each having a lens shape.

5. A three-dimensional stereoscopic image display apparatus, comprising:

a display apparatus which displays a two-dimensional image;

a multifocal lens array which comprises;

a planar surface;

a plurality of lenses arranged on said planar surface and having respective focal distances; and

a stereoscopic diffusing surface inclined relative to said planar surface,

wherein said respective focal distances of said plurality of lenses are selected so that a focal point-containing surface is formed at said surface inclined relative to said planar surface,

and which is disposed in a position at which light is incident from a display screen of said display apparatus;

a transparent or semi-transparent reflecting object having a surface which is positioned at said focal point-containing surface and which reflects light from the display screen of said display apparatus which has been formed into an image via said multifocal lens array;

driving means for driving said reflecting object and said multifocal lens array such that said reflecting object and said multifocal lens array move periodically while maintaining a spacing between the display screen of said display apparatus and said multifocal lens array; and

image data producing means for producing data for two-dimensional images displayed by said display apparatus such that a sectional image of a three-dimensional stereoscopic image is rendered on said surface of said reflecting object by light from the two-dimensional image displayed on the display screen of said display apparatus, and in synchronization with the movement of said reflecting object and said multifocal lens array, sectional images of said three-dimensional stereoscopic image at positions corresponding to the movement are rendered on said surface of said reflecting object.

6. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein said reflecting object has a plurality of reflecting surfaces.

7. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein the periodic movement has a frequency of not less than 5 Hz.

8. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein said driving means carries out the driving such that said reflecting object and said multifocal lens array undergo periodic parallel movement in an optical path of the light from the display screen of said display apparatus.

9. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein said display apparatus is a flat display apparatus.

10. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein said display apparatus employs image projection and is a projection-type display apparatus.

11. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein said image data producing means produces the two-dimensional image data in synchronization with a signal relating to the driving of said reflecting object from said driving means.

12. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein said display apparatus displays a monochromatic two-dimensional image, said reflecting object has a plurality of reflecting surfaces, and materials that convert and reflect different colors are used respectively on said reflecting surfaces of said reflecting object, whereby a color stereoscopic image is composed.

13. A three-dimensional stereoscopic image display apparatus, comprising:

a plurality of three-dimensional stereoscopic image display apparatuses according to claim 5 arranged side-by-side,

whereby the plurality of three-dimensional stereoscopic image display apparatuses display a three-dimensional stereoscopic image which is divided over the plurality of said reflecting objects.

14. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein the stereoscopic diffusing surface is provided by a stereoscopic diffusing panel that comprises a plurality of films each comprising a planar surface arranged parallel to one another at equal intervals so that each of the films is positioned obliquely relative to the planar surface, and that is movably supported directly above the planar surface in an optical path from the planar surface.

15. The three-dimensional stereoscopic image display apparatus according to claim 5, wherein the plurality of lenses is a plurality of discrete lenses arranged on said planar surface in an array and having a lens shape.

16. A three-dimensional stereoscopic image display apparatus, comprising:

a display apparatus which displays a two-dimensional image;

a multifocal lens array, which comprises

a planar surface,

a plurality of lenses arranged on said planar surface and having respective focal distances, and

a surface inclined relative to said planar surface,

wherein said respective focal distances of said plurality of lenses are selected so that a focal point-containing surface is formed at said surface inclined relative to said planar surface,

and which is disposed in a position at which light is incident from a display screen of said display apparatus;

a transparent or semi-transparent reflecting object having a surface which is positioned at said focal point-containing surface and which reflects light from the display screen of said display apparatus which has been formed into an image via said multifocal lens array;

driving means for driving said reflecting object and said multifocal lens array such that said reflecting object and said multifocal lens array move periodically while maintaining a spacing between the display screen of said display apparatus and said multifocal lens array, wherein said driving means carries out the driving such that said reflecting object and said multifocal lens array rotate periodically in an optical path of the light from the display screen of said display apparatus; and

image data producing means for producing data for two-dimensional images displayed by said display apparatus such that a sectional image of a three-dimensional stereoscopic image is rendered on said surface of said reflecting object by light from the two-dimensional image displayed on the display screen of said display apparatus, and in synchronization with the movement of said reflecting object and said multifocal lens array, sectional images of said three-dimensional stereoscopic image at positions corresponding to the movement are rendered on said surface of said reflecting object.

17. A three-dimensional stereoscopic image display apparatus, comprising:

a display apparatus which displays a two-dimensional image;

a multifocal lens array which comprises

a planar surface,

a plurality of lenses arranged on said planar surface and having respective focal distances, and

a surface inclined relative to said planar surface,

wherein said respective focal distances of said plurality of lenses are selected so that a focal point-containing surface is formed at said surface inclined relative to said planar surface,

and which is disposed in a position at which light is incident from a display screen of said display apparatus;

a transparent or semi-transparent reflecting object having a surface which is positioned at said focal point-containing surface and which reflects light from the display screen of said display apparatus which has been formed into an image via said multifocal lens array, wherein said reflecting object has (a) glass beads or (b) fluorescent paint attached to said surface;

driving means for driving said reflecting object and said multifocal lens array such that said reflecting object and said multifocal lens array move periodically while maintaining a spacing between the display screen of said display apparatus and said multifocal lens array; and

image data producing means for producing data for two-dimensional images displayed by said display apparatus such that a sectional image of a three-dimensional stereoscopic image is rendered on said surface of said reflecting object by light from the two-dimensional image displayed on the display screen of said display apparatus and in synchronization with the movement of said reflecting object and said multifocal lens array sectional images of said three-dimensional stereoscopic image at positions corresponding to the movement are rendered on said surface of said reflecting object.