Image Display Optical System, Image Display Unit, Illuminating Optical System, And Liquid Crystal Display Unit

• US 20080094586A1
• Filed: 08/29/2005
• Published: 04/24/2008
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Hirayama, Yoshikazu
• Granted Patent: US 7,778,508 B2
• Time in Patent Office: Days
• US Class Current: 353/98
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

Image display optical systems are disclosed that extend the angle of view longitudinally and transversely while saving space. The image display optical system includes a prism-shaped substrate transparent to an image-carrying light flux to be projected to a viewing eye, an introduction unit that guides the image-carrying light flux to a propagation path through which the image-carrying light flux propagates in a direction in which the image-carrying light flux from the outside enables internal reflection at least at three surfaces including at least one side of the substrate, and an output unit that guides the image-carrying light flux propagating through the substrate from the substrate to the viewing eye. By internally reflecting the image-carrying light flux at all the sides, i.e., three or more sides of the prism-shaped substrate, the propagation path is folded to be smaller and extends the opening angle of the light ray included in the image-carrying light flux longitudinally and transversely without increasing the substrate'"'"'s size.

Claims

1. An image display optical system, comprising:

a prism-shaped substrate transparent to an image-carrying light flux to be projected to a viewing eye;

an introduction unit that guides said image-carrying light flux in a direction in which said image-carrying light flux from the outside becomes capable of internal reflection at least at three surfaces including at least one side of said substrate; and

an output unit that guides said image-carrying light flux that propagates through said substrate from said substrate to said viewing eye.

2. The image display optical system according to claim 1, wherein said introduction unit includes a reflecting surface nonparallel to all the sides at which said image-carrying light flux is reflected.

3. The image display optical system according to claim 1, wherein said output unit includes a plurality of partially reflecting surfaces parallel to one another provided inside said substrate.

4. The image display optical system according to claim 1, wherein said output unit includes:

an optical film provided on at least a portion of the surface of said substrate said image-carrying light flux reaches and which emits part of said image-carrying light flux to the outside; and

a plurality of reflecting surfaces parallel to one another provided on the opposite side of the substrate of said optical film.

5. The image display optical system according to claim 34, wherein any one of said plurality of reflecting surfaces includes a holographic optical film.

6. The image display optical system according to claim 4, wherein any one of said plurality of reflecting surfaces includes a holographic optical film.

7. The image display optical system according to claim 1, wherein said output unit includes a holographic optical film provided on any one of the sides of said substrate.

8. An image display unit, comprising:

an image display device that emits an image-carrying light flux to be projected to a viewing eye; and

the image display optical system according to any one of claim 1 to claim 7, which guides said image-carrying light flux to said viewing eye.

9. The image display unit of claim 8, further comprising a mounting unit that mounts said image display unit on the head of a viewer.

10. An illuminating optical system, comprising:

a prism-shaped substrate transparent to an illumination light flux to illuminate a region to be illuminated;

an introduction unit that guides said illumination light flux in a direction in which said illumination light flux from the outside becomes capable of internal reflection at least at three surfaces including at least one side of said substrate; and

an output unit that guides said illumination light flux that propagates through said substrate from said substrate to said region to be illuminated.

11. The illuminating optical system according to claim 10, wherein said introduction unit includes a reflecting surface nonparallel to all the sides at which said illumination light flux is reflected.

12. The illuminating optical system according to claim 10, wherein said output unit includes a plurality of partially reflecting surfaces parallel to one another provided inside said substrate.

13. The illuminating optical system according to claim 10, wherein said output unit includes:

an optical film provided on at least a portion of the surface of said substrate said illumination light flux reaches and which emits part of said illumination light flux to the outside; and

a plurality of reflecting surfaces parallel to one another provided on the opposite side of the substrate of said optical film.

14. The illuminating optical system according to claim 12, wherein any one of said plurality of reflecting surfaces includes a holographic optical film.

15. The illuminating optical system according to claim 13, wherein any one of said plurality of reflecting surfaces includes a holographic optical film.

16. The illuminating optical system according to claim 10, wherein said output unit includes a holographic optical film provided on any one of the sides of said substrate.

17. A liquid crystal display unit, comprising:

a light source that emits an illumination light flux to illuminate a liquid crystal panel; and

the illuminating optical system according to any one of claim 10 to claim 16, which guides said illumination light flux to said liquid crystal panel.