Edge light panel

• US 5,178,447 A
• Filed: 06/26/1991
• Issued: 01/12/1993
• Est. Priority Date: 06/26/1990
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Meitaku Shisutemu
• Original Assignee: Kabushiki Kaisha Meitaku Shisutemu
• Inventors: Murase, Shinzo, Matsui, Hirokazu
• Primary Examiner(s): Ostrager, Allen M.
• Assistant Examiner(s): HEYMAN, LEONARD
• Application Number:
  US07/722,548
• Time in Patent Office: 566 Days
• Field of Search: 362/31, 362/32, 362/26, 362/27, 362/330, 359/49, 359/50
• US Class Current: 362/621
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G09F 2013/1813 provided with a coating showing a pattern of dots of variable density

Abstract

There is provided an edge-illuminating emitter panel or edge light panel in a liquid crystal display device. The edge light panel includes a transparent resin substrate having an irregular reflection surface with a mesh pattern formed thereon. A mesh size of the pattern varies with the distance away from a primary light source which is juxtaposed with a side of the substrate. The side is so finished as to provide a rough surface for permitting light issued from the light source to effectively enter the substrate. The rough surface is continually formed along the side. The thus formed rough surface ensures the light incident on the side a sure entrance as well as a sure difusion thereof, whereby the edge light panel improves the display device in brightness and uniformity of in display clarity. The rough surface may be formed intermittently or formed on at least a part of the side. The rough surface may be so formed as to have its roughness vary stepwise or continuously with the distance away from the light source.

Claims

1. An edge light panel for a surface light source device having at least one primary light source, comprising:

a transparent resin substrate having a plurality of edge surfaces about a periphery thereof, a front surface, and a rear surface;

wherein said rear surface of said transparent resin substrate has a mesh pattern formed thereon to define an irregular reflection surface;

wherein at least one of said plurality of edge surfaces is adapted to be juxtaposed with the at least one primary light source, and comprises means for permitting light from the at least one primary light source incident on said at least one of said plurality of edge surfaces, respectively, to pass through said at least one of said plurality of edge surfaces and into said transparent resin substrate;

wherein said means comprises a roughened portion of said at least one of said plurality of edge surfaces;

wherein said roughened portion of said at least one of said plurality of edge surfaces is formed intermittently along said at least one of said plurality of edge surfaces; and

wherein said mesh pattern has mesh sizes which vary as a function of the distance from said at least one of said plurality of edge surfaces.

17. An edge light panel as recited in claim 1, wherein

said at least one of said plurality of edge surfaces comprises two opposing ones of said plurality of edge surfaces.

18. An edge light panel as recited in claim 1, wherein

said at least one of said plurality of edge surfaces comprises only one of said plurality of edge surfaces.

2. An edge light panel for a surface light source device having at least one primary light source, comprising:

a transparent resin substrate having a plurality of edge surfaces about a periphery thereof, a front surface, and a rear surface;

wherein said rear surface of said transparent resin substrate has a mesh pattern formed thereon to define an irregular reflection surface;

wherein at least one of said plurality of edge surfaces is adapted to be juxtaposed with the at least one primary light source, and comprises means for permitting light from the at least one primary light source incident on said at least one of said plurality of edge surfaces, respectively, to pass through said at least one of said plurality of edge surfaces and into said transparent resin substrate;

wherein said means comprises a roughened portion of said at least one of said plurality of edge surfaces;

wherein said roughened portion of said at least one of said plurality of edge surfaces is formed over only a part of said at least one of said plurality of edge surfaces; and

wherein said mesh pattern has mesh sizes which vary as a function of the distance from said at least one of said plurality of edge surfaces.

15. An edge light panel as recited in claim 2, wherein

said at least one of said plurality of edge surfaces comprises two opposing ones of said plurality of edge surfaces.

16. An edge light panel as recited in claim 2, wherein

said at least one of said plurality of edge surfaces comprises only one of said plurality of edge surfaces.

3. An edge light panel for a surface light source device having at least one primary light source, comprising:

a transparent resin substrate having a plurality of edge surfaces about a periphery thereof, a front surface, and a rear surface;

wherein said rear surface of said transparent resin substrate has a mesh pattern formed thereon to define an irregular reflection surface;

wherein at least one of said plurality of edge surfaces is adapted to be juxtaposed with the at least one primary light source, and comprises means for permitting light from the at least one primary light source incident on said at least one of said plurality of edge surfaces, respectively, to pass through said at least one of said plurality of edge surfaces and into said transparent resin substrate;

wherein said means comprises a roughened portion of said at least one of said plurality of edge surfaces;

wherein said roughened portion of said at least one of said plurality of edge surfaces is formed only near opposing ends of said at least one of said plurality of edge surfaces; and

wherein said mesh pattern has mesh sizes which vary as a function of the distance from said at least one of said plurality of edge surfaces.

13. An edge light panel as recited in claim 3, wherein

said at least one of said plurality of edge surfaces comprises two opposing ones of said plurality of edge surfaces.

14. An edge light panel as recited in claim 3, wherein

said at least one of said plurality of edge surfaces comprises only one of said plurality of edge surfaces.

4. An edge light panel for a surface light source device having at least one primary light source, comprising:

a transparent resin substrate having a plurality of edge surfaces about a periphery thereof, a front surface, and a rear surface;

wherein said rear surface of said transparent resin substrate has a mesh pattern formed thereon to define an irregular reflection surface;

wherein at least one of said plurality of edge surfaces is adapted to be juxtaposed with the at least one primary light source, and comprises means for permitting light from the at least one primary light source incident on said at least one of said plurality of edge surfaces, respectively, to pass through said at least one of said plurality of edge surfaces and into said transparent resin substrate;

wherein said means comprises a roughened portion of said at least one of said plurality of edge surfaces;

wherein said roughened portion of said at least one of said plurality of edge surfaces is formed with a degree of coarseness which varies along said at least one of said plurality of edge surfaces; and

wherein said mesh pattern has mesh sizes which vary as a function of the distance from said at least one of said plurality of edge surfaces.

5. An edge light panel as recited in claim 4, wherein

said degree of coarseness varies in a continuous manner along said at least one of said plurality of edge surfaces.

6. An edge light panel as recited in claim 4, wherein

said degree of coarseness varies in a stepwise manner along said at least one of said plurality of edge surfaces.

7. An edge light panel as recited in claim 4, wherein

said at least one of said plurality of edge surfaces comprises two opposing ones of said plurality of edge surfaces.

8. An edge light panel as recited in claim 7, wherein

said mesh pattern is formed on said rear surface of said transparent resin substrate in such a manner that the mesh sizes are largest in a zone midway between said two opposing ones of said plurality of edge surfaces.

9. An edge light panel as recited in claim 8, wherein

said zone is elongated in parallel with said two opposing ones of said plurality of edge surfaces.

10. An edge light panel as recited in claim 4, wherein

said at least one of said plurality of edge surfaces comprises only one of said plurality of edge surfaces.

11. An edge light panel as recited in claim 10, wherein

said mesh pattern is formed on said rear surface of said transparent resin substrate in such a manner that the mesh sizes are largest in a zone between said only one of said plurality of edge surfaces and another one of said plurality of edge surfaces opposite said only one of said plurality of edge surfaces, and nearer to said another one of said plurality of edge surfaces.

12. An edge light panel as recited in claim 11, wherein

said zone is elongated in parallel with said only one of said plurality of edge surfaces.