Optical element, and lighting device, display device and electronic device that use the optical element

• US 8,269,919 B2
• Filed: 09/23/2011
• Issued: 09/18/2012
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NLT Technologies, Ltd.
• Inventors: Mimura, Koji, Sumiyoshi, Ken
• Primary Examiner(s): Allen, Stephone
• Assistant Examiner(s): Kakalec, Kimberly N
• Application Number:
  US13/242,251
• Publication Number:
  US 20120013560A1
• Time in Patent Office: 361 Days
• Field of Search: 359462-477, 359/613, 349 55-166, 428 11- 162
• US Class Current: 349/66
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides

Abstract

A micro-louver (1) includes: a transparent substrate (2); a concavoconvex shape portion (5) formed on at least one surface of the transparent substrate (2) and in a prescribed pattern for diffracting incident light to form an image; and a light controlling layer (7) including at least one transparent layer (3) and at least light-absorption layer (4) arranged alternately on said at least one surface of the transparent substrate (2), each of said at least one transparent layer (3) and said at least one transparent layer (4) extending in a direction that intersects said at least one surface of the transparent substrate (2).

Claims

1. A display device comprising:

(a) an optical element comprising;

a transparent substrate,

a concavoconvex shape portion formed on at least one surface of the transparent substrate and in a prescribed pattern for diffracting incident light to form an image, wherein said concavoconvex shape portion is a transmissive-type diffraction grating that generates a diffraction image, and

a light controlling layer including at least one transparent portion and at least one light-absorption portion arranged alternately on said at least one surface of the transparent substrate, each of said at least one transparent portion and said at least one light-absorption portion extending in a direction that intersects said at least one surface; and

(b) an optical control element for forming a display image,

wherein the optical element is arranged on a display surface side of the optical control element such that a surface of the optical element, which is on a side opposite to a side of the transparent substrate on which the concavoconvex shape portion is formed, faces the optical control element,

wherein said at least one transparent portion and said at least one light-absorption portion are constituted to display the display image in a first angle region located in a front direction with regard to a display surface of the optical element, wherein the display image has a higher amount of light than an image formed by the concavoconvex shape portion, and

wherein the concavoconvex shape portion is constituted to display the image in a second angle region located in an oblique direction with regard to the display surface of the optical element, wherein the image has a higher amount of light than the display image.

2. The display device according to claim 1, wherein the concavoconvex shape portion and said at least one transparent portion are formed on a same surface of the transparent substrate and are formed by members having different indices of refraction.

3. The display device according to claim 1, wherein the concavoconvex shape portion is formed by a member that differs from the transparent substrate and that is bonded onto the transparent substrate.

4. The display device according to claim 1, further comprising a touch panel, wherein the touch panel is arranged on the display surface side of the optical control element.

5. An electronic device comprising:

the display device according to claim 1

wherein the at least one light-absorption portion limits the emission of light in a direction that is oblique with respect to the transparent substrate, and

wherein the image is a fixed diffraction image that corresponds to the prescribed pattern.

6. A cellular phone comprising:

the display device according to claim 1

wherein the at least one light-absorption portion limits the emission of light in a direction that is oblique with respect to the transparent substrate, and

wherein the image is a fixed diffraction image that corresponds to the prescribed pattern.

7. A portable computer comprising:

a display device according to claim 1;

wherein the at least one light-absorption portion limits the emission of light in a direction that is oblique with respect to the transparent substrate, and

wherein the image is a fixed diffraction image that corresponds to the prescribed pattern.

8. An automated teller machine comprising:

a display device according to claim 1;

wherein the at least one light-absorption portion limits the emission of light in a direction that is oblique with respect to the transparent substrate, and

wherein the image is a fixed diffraction image that corresponds to the prescribed pattern.

9. The automated teller machine according to claim 8, further comprising a touch panel, wherein the touch panel is arranged on the display surface side of the optical control element.