Lighting apparatus and liquid crystal display

• US 7,108,417 B2
• Filed: 12/10/2004
• Issued: 09/19/2006
• Est. Priority Date: 08/23/2002
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Maeda, Satoshi, Aritake, Hirokazu
• Primary Examiner(s): TSO, LAURA K
• Application Number:
  US11/010,128
• Publication Number:
  US 20050117324A1
• Time in Patent Office: 648 Days
• Field of Search: 362/31, 362/26, 362/600, 362/611, 362/612, 362/624, 362/623, 362/626
• US Class Current: 362/626
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• 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 plurality of first light reflection parts 20a in the form of a first V-shaped groove, for reflecting light entering from a first light source 12a and a plurality of light reflection parts 20b in the form of a second V-shaped groove, for reflecting light entering from a second light source 12b are formed, an intersection angle θ_P of the planes of the first V-shaped groove and an intersection angle θ_P of the planes of the second V-shaped grooves are substantially equal to each other, the planes of said plurality of first light reflection parts and the planes of said plurality of second light reflection parts are tilted at respective angles at which the light exits in the direction substantially perpendicular to the longitudinal direction of the linear light conductor 14, said plurality of first light reflection parts are formed in at least a region near the end of the linear light conductor, opposite to the end thereof near which the first light source is disposed, and said plurality of second reflection parts are formed in at least a region near the end of the linear light conductor opposite to the end thereof near which the second light source is disposed.

Claims

1. A lighting apparatus comprising a first light source, a second light source spaced from the first light source, and a linear light conductor disposed between the first light source and the second light source, for causing light entering from the first light source and the second light source to exit linearly from an exit side,

on the reflection side of the linear light conductor, which is opposed to the exit side, a plurality of first light reflection parts in the form of first V-shaped grooves, for reflecting light entering from the first light source and a plurality of second light reflection parts in the form of second V-shaped grooves, for reflecting light entering from the second light source being formed, and an intersection angle of the planes of the first V-shaped groove and an intersection angle of the planes of the second V-shaped grooves being substantially equal to each other,

a plurality of the first reflection planes which are respective ones of the planes of the first V-shaped grooves, which are on the side of the first light source, being tilted at respective angles at which the light entering from the first light source exits in the direction substantially perpendicular to the longitudinal direction of the linear light conductor, and an intersection angle of the planes of the first V-shaped grooves being substantially equal to each other,

a plurality of the second reflection planes which are respective ones of planes of the second V-shaped grooves, which are on the side of the second light source, being tilted at respective angles at which the light entering from the second light source exits in the direction substantially perpendicular to the longitudinal direction of the linear light conductor, an intersection angle of the planes of the second V-shaped grooves being substantially equal to each other, and the intersection angle of the planes of the first V-shaped grooves and the intersection angle of the planes of the second V-shaped grooves being substantially equal to each other, and

said plurality of first light reflection parts being formed in at least a region near the end of the linear light conductor, opposite to the end thereof near which the first light source is disposed, and said plurality of second reflection parts being formed in at least a region near the end of the linear light conductor opposite to the end thereof near which the second light source is disposed.

2. A lighting apparatus according to claim 1, wherein

the first light reflection parts and the second light reflection parts are formed substantially alternately.

3. A lighting apparatus according to claim 1, wherein

the planes of said plurality of the first light reflection parts are respectively tilted so that when a pitch of the first light reflection parts adjacent to each other is Δ

X, and a change of the inclination angles is Δ

θ

, an absolute value of Δ

θ

/Δ

X is 2.71 degrees/mm or less.

4. A lighting apparatus according to claim 3, wherein

the planes of said plurality of first light reflection parts are respectively titled so that an absolute value of a change amount of Δ

θ

/Δ

X with respect to a longitudinal distance of the linear light conductor is 0.70 degrees/mm or less.

5. A lighting apparatus according to any one of claims 1 to 4, further comprising

a planar light conductor optically connected to the linear light conductor, for emitting light entering from the linear light conductor in plane.

6. A lighting apparatus according to claim 1, further comprising

a reflection coat film formed on the reflection side of the linear light conductor.

7. A lighting apparatus according to claim 1, wherein

a reflector is disposed on the reflection side of the linear light conductor independent of the linear light conductor.

8. A liquid crystal display comprising a lighting apparatus including a first light source, a second light source spaced from the first light source, a linear light conductor disposed between the first light source and the second light source, for causing light entering from the first light source and the second light source to exit linearly from an exit side, and a planar light conductor optically connected to the linear light conductor, for emitting light entering from the linear light conductor in plane;

and a liquid crystal panel illuminated by the lighting apparatus,

on the reflection side of the linear light conductor, which is opposed to the exit side, a plurality of first light reflection parts in the form of first V-shaped grooves, for reflecting light entering from the first light source and a plurality of light reflection parts in the form of second V-shaped grooves, for reflecting light entering from the second light source being formed, and an intersection angle of the planes of the first V-shaped groove and an intersection angle of the planes of the second V-shaped grooves being substantially equal to each other,

the planes of said plurality of first light reflection parts being tilted at respective angles at which the light entering from the first light source exits in the direction substantially perpendicular to the longitudinal direction of the linear light conductor, and the planes of said plurality of second light reflection parts being tilted at respective angles at which the light entering from the second light source exits in the direction substantially perpendicular to the longitudinal direction of the linear light conductor, and

said plurality of first light reflection parts being formed in at least a region near the end of the linear light conductor, opposite to the end thereof near which the first light source is disposed, and said plurality of second reflection parts being formed in at least a region near the end of the linear light conductor opposite to the end thereof near which the second light source is disposed.