Optical device

Patent metadata

Field	Value
Publication number	US-10114226-B2
Application number	US-201715455590-A
Country	US
Kind code	B2
Filing date	Mar 10, 2017
Priority date	Oct 6, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

An optical device includes a light guiding plate which guides lights within the surface parallel to an emission surface, and light converging sections onto which the lights guided by the light guiding plate are incident, each of the light converging sections having an optical surface which allows an emitted light to be emitted from the emission surface in a direction where the emitted light is to be substantially converged on one convergence point or convergence line in space or to be substantially diverged from one convergence point or convergence line in space. The light converging sections are formed respectively along a predetermined line within the surface parallel to the emission surface, and the convergence points or the convergence lines are different from each other among the light converging sections, and an image is formed in space by an aggregation of the convergence points or the convergence lines.

First claim

What is claimed is:

1. An optical device, comprising:
a light guiding plate which guides lights within a surface parallel to an emission surface; and
a plurality of light converging sections onto which the lights guided by the light guiding plate are incident, each of the plurality of light converging sections having an optical surface which allows the lights guided by the light guiding plate to be emitted from the emission surface in a direction where the emitted light is to be substantially converged on one convergence point or convergence line in space viewed from a distance by a viewer, or to be substantially diverged from one convergence point or convergence line in space viewed from a distance by a viewer, wherein
the plurality of light converging sections are formed respectively along a predetermined line within the surface parallel to the emission surface,
the convergence points or the convergence lines are different from each other among the plurality of light converging sections and an image is formed in space distant from the viewer by an aggregation of a plurality of the convergence points or the convergence lines, and
each of the plurality of light converging sections comprise a plurality of reflection surfaces on a main surface angled to be non-parallel with an opposing emission surface so as to cause lights reflected off the plurality of reflection surfaces to converge on a common point or line.

2. An optical device, comprising:
a light guiding plate which guides lights within a surface parallel to an emission surface; and
a plurality of light converging sections onto which the lights guided by the light guiding plate are respectively incident, the plurality of light converging sections formed respectively with a length in a direction orthogonal to a light guiding direction of the light guiding plate within the surface parallel to the emission surface, wherein
each of the plurality of light converging sections has an optical surface where a direction of a normal line continuously or intermittently changes along a lengthwise direction of each of the light converging sections when the normal line is projected onto the surface parallel to the emission surface, and allows the lights guided by the light guiding plate to be emitted from the emission surface in a direction where the lights guided by the light guiding plate are, by being reflected by the optical surface, substantially converged on one convergence point or convergence line in space viewed from a distance by a viewer, or substantially diverged from one convergence point or convergence line in space viewed from a distance by a viewer,
the convergence points or the convergence lines are different from each other among the plurality of light converging sections, and an image is formed in space distant from the viewer by an aggregation of a plurality of the convergence points or the convergence lines, and
each of the plurality of light converging sections comprise a plurality of reflection surfaces on a main surface angled to be non-parallel with an opposing emission surface so as to cause lights reflected off the plurality of reflection surfaces to converge on a common point or line.

3. The optical device according to claim 1 or 2 , wherein
a spread angle of the lights guided by the light guiding plate at each point within the light guiding plate is 5° or less within the surface parallel to the emission surface.

4. The optical device according to claim 1 or 2 , satisfying 1.5θ<Φ Δp /5,
where θ is a spread angle of the lights guided by the light guiding plate at each point within the light guiding plate, and Φ Δp is an angle formed by lines connecting two end points of the image with each of the plurality of light converging sections in a direction along a forming direction of the plurality of light converging sections.

5. The optical device according to claim 1 or 2 , satisfying 1.5θ<2Φ Δi ,
where θ is a spread angle of the lights guided by the light guiding plate at each point within the light guiding plate, and Φ Δi is an angle formed by lines connecting two feature points included in the image with each of the plurality of light converging sections when the lines are projected onto a surface orthogonal to a light guiding direction of the light guiding plate and the emission surface.

6. The optical device according to claim 1 or 2 , satisfying 1.5θ<2Φ Δr ,
where θ is a spread angle of the lights guided by the light guiding plate at each point within the light guiding plate, and Φ Δr is an angle formed by lines connecting two of the convergence points adjacent to each other in a direction along a forming direction of the plurality of light converging sections with each of the plurality of light converging sections when the lines are projected onto a surface orthogonal to a light guiding direction of the light guiding plate and the emission surface.

7. The optical device according to claim 1 or 2 , satisfying W≤L/10,
where L is a distance between an incident light end surface of the light guiding plate and a center of the emission surface, and W is a spread width of lights incident from the incident light end surface.

8. The optical device according to claim 1 or 2 , further comprising:
a light source; and
a light shielding section which is provided between an incident light end surface of the light guiding plate and the light source and has an aperture that limits lights incident from the light source onto the incident light end surface.

9. The optical device according to claim 1 or 2 , further comprising:
a light source; and
a collimating section which collimates lights from the light source to make the lights incident onto an incident light end surface of the light guiding plate.

10. The optical device according to claim 1 or 2 , wherein
at least one light converging section of the plurality of light converging sections has a plurality of reflection surfaces continuously arranged along a forming direction of the light converging section.

11. The optical device according to claim 1 or 2 , wherein
a length of each of the plurality of light converging sections in a direction orthogonal to a forming direction of each of the light converging sections is not above ½ of a distance between the light converging sections adjacent to each other in a direction orthogonal to the forming direction of each of the light converging sections.

12. The optical device according to claim 1 or 2 , wherein
at least one light converging section of the plurality of light converging sections includes a plurality of optical surfaces forming a diffraction grating.

13. The optical device according to claim 1 or 2 , wherein
at least one light converging section of the plurality of light converging sections includes, on a main emission surface of the light guiding plate, at least one cylindrical lens.

14. The optical device according to claim 1 or 2 , wherein
the plurality of light converging sections are formed along a straight line, a concave curve or a convex curve.

15. The optical device according to claim 1 or 2 , wherein
one of a light converging section having the convergence point or the convergence line on the emission surface side of the light guiding plate among the plurality of light converging sections and a light converging section having the convergence point or the convergence line on an opposite side to the emission surface of the light guiding plate among the plurality of light converging sections is formed along a convex curve, and the other is formed along a concave curve.

16

Assignees

• Omron Tateisi Electronics Co

Inventors

• Shinohara Masayuki
• Kitamura Norikazu
• Tanoue Yasuhiro
• Okuda Mitsuru
• Okada Kazuyuki

Classifications

• G09F13/18 Primary

  Edge-illuminated signs · CPC title

• G02B30/35

  using reflective optical elements in the optical path between the images and the observer · CPC title

• G02B30/27 Primary

  involving lenticular arrays · CPC title

• G02B6/0038

  Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide · CPC title

• G02B6/003

  Lens or lenticular sheet or layer · CPC title