Title:
BACK LIGHT DEVICE
Document Type and Number:
Japanese Patent JP3624577
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To actualize a back light which has high luminance and small luminance variation and luminance unevenness without being affected by the external shape, and to excellently reduce the size and assemble the device by forming a nearly channel-cross groove on the reverse surface of a photoconductor almost in parallel to the external edge part of a light emission area to the entire circumference except a light-source side external edge part.
SOLUTION: The back light 4 has the light emission area indicating a necessary light emission range and in this light emission area 13, the position of an LED 29, the shape of the light incidence part of the back light 4, etc., are determined. On the reverse surface of the back light 4, the nearly channel-cross section groove part 6 is provided almost in parallel to the outer peripheral edge of the light emission area 13, and the internal wall surface of this groove part 6 is formed into a mirror surface for totally reflecting projection light 14 emitted by a chip LED 29 with efficiency. Consequently, the luminance of the light emission area 13 is increased without being affected by occurring irregular reflection, luminance variance and luminance unevenness are improved, and uniform luminance can be obtained.
Inventors:
Toshiyasu Kitamura
Kunihiro Konishi
Kunihiro Konishi
Application Number:
JP25610596A
Publication Date:
March 02, 2005
Filing Date:
September 27, 1996
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G02B6/00; F21V8/00; G02F1/1335; G02F1/13357; (IPC1-7): G02F1/13357; F21V8/00; G02B6/00
Domestic Patent References:
| JP8029625A | ||||
| JP7191319A | ||||
| JP6289231A | ||||
| JP9281341A | ||||
| JP9198908A | ||||
| JP9203898A |
Attorney, Agent or Firm:
Fumio Iwahashi
Tomoyasu Sakaguchi
Hiroki Naito
Tomoyasu Sakaguchi
Hiroki Naito