Surface luminous source panel with areas having different reflector speck densities

• US 5,283,673 A
• Filed: 09/04/1991
• Issued: 02/01/1994
• Est. Priority Date: 09/30/1989
• 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): Sikes, William L.
• Assistant Examiner(s): TRICE, RONALD
• Application Number:
  US07/756,260
• Time in Patent Office: 881 Days
• Field of Search: 362/31, 362/32, 362/23, 362/26, 40/546, 40/547, 359/70, 359/69, 359/49
• US Class Current: 349/65
• 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: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G09F 2013/1813 provided with a coating showing a pattern of dots of variable density

Abstract

There is provided a surface luminous source panel comprising an irregular reflection layer carrying on it a large number of irregular reflector specks and arranged on the surface of a transparent substrate. The reflection layer has a parallel pattern section having an area of irregular reflector specks per unit length of the layer which smoothly increases with the distance from a light source along the panel; and a regulating pattern section located close to the light source and partially surrounded by the parallel pattern section. The regulating pattern section has a hill-shaped contour starting from the edge close to the light source and an area of irregular reflector specks per unit length of the layer also smoothly increasing with the distance from the light source but at a rate smaller than that of the parallel pattern section. Such a surface luminous source panel can provide a luminous source with very evenly distributed brightness and therefore find useful applications in, for example, word processors and display stands.

Claims

1. A surface luminous source panel for use in a surface luminous source apparatus having a first light source and a second light source, said surface luminous source panel comprising:

a transparent substrate having opposing faces and a plurality of peripheral edges, a first of said peripheral edges being disposed at a first end of said transparent substrate and being positioned adjacent said first light source, and a second of said peripheral edges being disposed at a second end of said transparent substrate opposite said first end thereof and being positioned adjacent said second light source; and

an irregular reflection layer comprising irregular reflector specks arranged on one of said opposing faces of said transparent substrate, said irregular reflection layer including a parallel pattern section in which said irregular reflector specks occupy an area per unit length of said irregular reflection layer which smoothly increases at a first rate with a distance from said first peripheral edge in an area between said second peripheral edge and a center location midway between said first and second peripheral edges and with a distance from said second peripheral edge in an area between said second peripheral edge and said center location, and first and second regulating pattern sections in which said irregular reflector specks occupy an area per unit length of said irregular reflection layer which smoothly increases at a second rate with a distance from said first and second peripheral edges, respectively, said first rate being greater than said second rate; and

wherein said one of said opposing faces of said transparent substrate includes first and second narrow margin portions extending adjacent and parallel to said first and second peripheral edges, respectively, said first and second narrow margin portions being free of said irregular reflector specks.

2. A surface luminous source panel as recited in claim 1, wherein

said first and second regulating pattern sections are disposed adjacent said first and second narrow margin portions, respectively.

3. A surface luminous source panel as recited in claim 2, wherein

said first regulating pattern section is shaped such that it has two parallel borders, both of which are parallel with said first peripheral edge;

and

said second regulating pattern section is shaped such that it has two parallel borders, both of which are parallel with said second peripheral edge.

4. A surface luminous source panel for use in a surface luminous source apparatus having a first light source and a second light source, said surface luminous source panel comprising:

a transparent substrate having opposing faces and plurality of peripheral edges, a first of said peripheral edge being disposed at a first end of said transparent substrate and being positioned adjacent said first light source, and a second of said peripheral edges being disposed at a second end of said transparent substrate opposite said first end thereof and being positioned adjacent said second light source; and

an irregular reflection layer comprising irregular reflector specks arranged on one of said opposing faces of said transparent substrate, said irregular reflection layer including a parallel pattern section in which said irregular reflection specks occupy in area per unit length of said irregular reflection layer which smoothly increases at a first rate with a distance from said first peripheral edge in area between said second peripheral edge and a center location midway between said first and second peripheral edges and with a distance from said second peripheral edge in area between said second peripheral edge said center location, and first and second regulating pattern sections in which said irregular reflector specks occupy an area per unit length of said irregular reflection layer which smoothly increases at a second rate with a distance from said first and second peripheral edges, respectively, said first rate being greater than said second rate; and

wherein said one of said opposing faces of said transparent substrate includes a plurality of narrow margin portions extending adjacent and parallel to said plurality of peripheral edges, respectively, said narrow margin portions being free of said irregular reflection specks.