Hollow surface illuminator

• US 6,809,892 B2
• Filed: 06/06/2003
• Issued: 10/26/2004
• Est. Priority Date: 07/26/2000
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Toyooka, Kazuhiko
• Primary Examiner(s): Cherry, Euncha P.
• Application Number:
  US10/333,391
• Publication Number:
  US 20040012943A1
• Time in Patent Office: 508 Days
• Field of Search: 359/831, 359/833, 359/834, 359/528, 349/67, 362/31, 385/133
• US Class Current: 359/833
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide

Abstract

A light-conducting unit which can effectively balance the light-leaking effect and the light-propagation effect of the prismatic films forming the light-conducting space, and satisfy the requirements to reduce the weight of the unit is disclosed. A light-conducting unit comprising the first prismatic film and the second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which is a flat surface, said prismatic surface carrying prisms arranged substantially parallel to each other, wherein said two prismatic films are arranged so that the first edges of said prismatic films are positioned to form an opening, a light-conducting space is formed between said prismatic films, and the height of said light-conducting space does not substantially increase from said opening to the remote edges of the prismatic films opposing said opening, and the major surface of said first prismatic film which faces outside said light-conducting space is a light-emitting surface, and the arrangement of the both prismatic films and the directions of the prisms of the both prismatic films in relation to the incident direction of light are defined under the specific conditions.

Claims

1. A light-conducting unit comprising a first prismatic film and a second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which carries no prism, said prismatic surface carrying a plurality of prisms which are arranged substantially parallel to each other along the lengthwise direction of the prisms,

wherein said two prismatic films are arranged so that the first edges of said prismatic films are positioned substantially parallel to each other leaving a gap between them to form an opening, a light-conducting space which is in continuous from said opening formed between said prismatic films, and the height of said light-conducting space does not substantially increase from said opening to the remote edges of said prismatic films opposing said opening, and

the major surface of said first prismatic film, which faces outside said light-conducting space, is a light-emitting surface to emit light which is propagated from said opening into said light-conducting space, and said prismatic surface of said first prismatic film is placed facing outside of said light-conducting space, and the direction of said prisms of said first prismatic film is not parallel to the direction of said light.

2. A light-conducting unit comprising a first prismatic film and a second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which carries no prism, said prismatic surface carrying a plurality of prisms which are arranged substantially parallel to each other along the lengthwise direction of the prisms,

wherein said two prismatic films are arranged so that the first edges of said prismatic films are positioned substantially parallel to each other leaving a gap between them to form an opening, a light-conducting space which is in continuous from said opening formed between said prismatic films, and the height of said light-conducting space does not substantially increase from said opening to the remote edges of said prismatic opposing said opening, and

the major surface of said first prismatic film which faces outside said light-conducting space is a light-emitting surface to emit light which is propagated from said opening into said light-conducting space and said prismatic surface of said first prismatic film is placed facing outside of said light-conducting space and the direction of said prisms of said first prismatic film is parallel to the direction of said light, and

that the direction of said prism of said second prismatic film is not parallel to the direction of said light.

3. A light-conducting unit comprising a first prismatic film and a second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which carries no prism, said prismatic surface carrying a plurality of prisms which are arranged substantially parallel to each other along the lengthwise direction of the prisms,

wherein said two prismatic films are arranged so that the first edges of said prismatic films are arranged substantially parallel to each other leaving a gap between them to form an opening and a light-conducting space which is in continuous from said opening formed between said prismatic films, and

the major surface of said first prismatic film, which faces outside said light-conducting space, is a light-emitting surface to emit light which is propagated from said opening into said light-conducting space, and in that said prismatic surface of said first prismatic film is placed facing outside of said light-conducting space, the direction of said prisms of said first prismatic film is parallel to the direction of said light, said prismatic surface of said second prismatic film is placed facing outside of said light-conducting space, and the direction of said prisms of said second prismatic film is parallel to the direction of said light, and

that said two prismatic films are arranged so that the height of said light-conducting space decreases from said opening to the remote edges of said prismatic films opposing said opening.

4. A light-conducting unit comprising a first prismatic film and a second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which carries no prism, said prismatic surface carrying a plurality of prisms which are arranged substantially parallel to each other along the lengthwise direction of the prisms,

wherein said two prismatic films are arranged so that the first edges of said prismatic films are positioned parallel to each other leaving a gap between them to form an opening, a light-conducting space which is in continuous from said opening formed between said prismatic films, and the height of said light-conducting space does not substantially increase from said opening to the remote edges of said prismatic films opposing said opening, and

the major surface of said first prismatic film which faces outside said light-conducting space is a light-emitting surface to emit light which is propagated from said opening into said light-conducting space, and said prismatic surface of said first prismatic film is placed facing inside of said light-conducting space, while said prismatic surface of said second prismatic film is placed facing outside of said light-conducting space.

5. A light-conducting unit comprising a first prismatic film and a second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which carries no prism, said prismatic surface carrying a plurality of prisms which are arranged substantially parallel to each other along the lengthwise direction of the prisms,

wherein said two prismatic films are arranged so that the first edges of said prismatic films are positioned substantially parallel to each other leaving a gap between them to form an opening, a light-conducting space which is in continuous from said opening formed between said prismatic films, and the height of said light-conducting space does not substantially increase from said opening to the remote edges of said prismatic films opposing said opening, and

the major surface of said first prismatic film, which faces outside said light-conducting space, is a light-emitting surface to emit light which is propagated from said opening into said light-conducting space, and said prismatic surface of said first prismatic film is placed facing inside of said light-conducting space, and also said prismatic surface of said second prismatic film is placed facing inside of said light-conducting space, and

that the arranging direction of said prism of said first prismatic film is not perpendicular to the incident direction of said light.

6. A light-conducting unit comprising the first prismatic film and the second prismatic film, each having two major surfaces, one of which is a prismatic surface, and the other of which is a flat surface carrying no prism, said prismatic surface carrying a plurality of prisms which are arranged substantially in parallel with each other along the lengthwise direction of the prisms,

wherein said two prismatic films are arranged so that the one edges of said prismatic films are positioned substantially in parallel with each other with leaving a gap between them to form an opening, a light-conducting space, which is in continuous from said opening, is formed between said prismatic films, and the height (the size in the thickness direction) of said light-conducting space does not substantially increase from said opening to the remote edges opposing said opening, and

the major surface of said first prismatic film, which faces outside said light-conducting space, is a light-emitting surface to emit light which is propagated from said opening into said light-conducting space,

characterized in that said prismatic surface of said first prismatic film is placed with facing inside of said light-conducting space, also said prismatic surface of said second prismatic film is placed with facing inside of said light-conducting space, and the arranging direction of said prisms of said first prismatic film is perpendicular to said incident direction of said light, and

that the apex angle of said prism of said first prismatic film is smaller than that of said prism of said second prismatic film.