EP0355064A2
Expired / Lapsed
EP
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Back lighting device for a liquid crystal panel
Assignee: Tosoh Quartz Corp
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Filing: 1989-08-17
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Granted: —
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Expires: 2009-08-17
Abstract
Abstract A back lighting device for a liquid crystal display (1) has a light scattering coating (4) in the form of dots covering the light emitting surface of a light guiding (2). The coating covers 3-50% of the surface nearest an end thereof adjacent a linear light source and covers 80-100% of the surface farthest from the light source. The variation of the coating rate across the surface produces uniform distribution of emitted light from the back lighting device.
Inventors
- 👤 Eiichi Yanagi
- 👤 Takumi Fukunishi
- 👤 Osamu Shoji
- 👤 Naoki Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 16:03
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0065; G02B6/0033; G02B6/0035; G02B6/004; G02B6/0043; G02B6/0058; G02B6/0061; G02B6/0066; G02B6/007; G02B6/0071
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
92 words
A back light device for a liquid crystal panel comprising: a photoconductive sheet member made of a transmissive material; a light source means to provide light to at least one edge of the sheet member; a first face of the photoconductive sheet member being provided with reflecting means for reflecting light emitted from the said first face back into the sheet member; and the other or second face of the photoconductive sheet member being provided with light scattering means, the said second face being the light emitting face of the photoconductive member.
Claim 2
Dependent Claim
92 words
A back light device for a liquid crystal panel comprising: a photoconductive sheet member made of a transmissive material; a light source means to provide light to at least one edge of the sheet member; a first face of the photoconductive sheet member being provided with reflecting means for reflecting light emitted from the said first face back into the sheet member; and the other or second face of the photoconductive sheet member being provided with light scattering means, the said second face being the light emitting face of the photoconductive member.
Claim 3
Dependent Claim
22 words
A back light device as claimed in Claim 1 in which the reflecting means are disposed discontinuously over the said first face.
Claim 4
Dependent Claim
34 words
A back light device as claimed in Claim 1 or Claim 2 in which the reflecting means are disposed so that the reflecting power varies from place to place over the said first surface.
Claim 5
Dependent Claim
29 words
A back light device as claimed in Claim 3 in which the reflecting power is least nearest the light source means and greatest furthest from the light source means.
Claim 6
Dependent Claim
44 words
A back light device as claimed in Claim 1, 2, 3 or 4 in which the reflecting means is a discontinuous array of light scattering materials having a refractive index higher than that of the said transmissive material of the said photoconductive sheet member.
Claim 7
Dependent Claim
110 words
A back light device for a liquid crystal panel comprising: a photo-conductive plate made of a transmissive material; a linear light source provided close to at least one side end portion of the said photo-conductive plate; a first surface of the said photo-conductive plate being partially coated with light scattering material having a refractive index higher than the said transmissive material of the said photo-conductive plate; a light reflecting plate covering said first surface of the said photo-conductive plate partially coated with the said light scattering material; and a light scattering plate provided on the other or second surface that is the light emitting surface of the said photo-conductive plate.
Claim 8
Dependent Claim
110 words
A back light device for a liquid crystal panel comprising: a photo-conductive plate made of a transmissive material; a linear light source provided close to at least one side end portion of the said photo-conductive plate; a first surface of the said photo-conductive plate being partially coated with light scattering material having a refractive index higher than the said transmissive material of the said photo-conductive plate; a light reflecting plate covering said first surface of the said photo-conductive plate partially coated with the said light scattering material; and a light scattering plate provided on the other or second surface that is the light emitting surface of the said photo-conductive plate.
Claim 9
Dependent Claim
51 words
A back light device according to any one of Claims 1 to 6, in which the said photo-conductive plate or member is coated with a dot-like array of the said light scattering material so that the coating rate thereof becomes larger as the distance from the said light source is larger.
Claim 10
Dependent Claim
62 words
A back light device according to any one of Claims 1 to 7, in which the said photo-conductive plate or member is partially coated with the said light scattering material so that the coating rate thereof is increased in proportion to x n , where x is the distance from the light source, and n is a number from 1.7 to 3.
Claim 11
Dependent Claim
47 words
A back light device according to Claims 7 or Claim 8 in which the coating rate adjacent the light source is 3 to 50% and the coating rate at the region of the plate or member most remote from the light source is from 80 to 100%.
References Cited (Backward Citations)
No citation records indexed.
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