EP0290266A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Elevated back-lit display
Assignee: 3M Co
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Filing: 1988-05-06
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Granted: —
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Expires: 2008-05-06
Abstract
Abstract An elevated back-lit display providing easy replacement of light sources and great uniformity of light distribution. A light source in a support column emits light into a light conduit also in the support column. Light is conducted through the light conduit to an optical cavity with an optical window. Light entering the optical cavity from the light conduit is dispersed throughout the optical cavity by a beam spreader. Total internal reflection film in said optical window helps to improve the uniformity of light distribution in the optical cavity.
Inventors
- 👤 John F. Jr. C/O Minnesota Mining And Dreyer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 21:07
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0033; G02B6/0035; G02B6/0038; G09; G09F; G09F13/00; G09F13/04; G09F13/0409
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
127 words
An elevated, back-lit display having a support column and means defining an optical cavity having an optical window on top of said support column, said display characterized in that it further comprises: a light source and a light conduit in said support column, said light source being positioned to emit light into said light conduit; a transparent film having a smooth side and a structured side positioned in said optical window, said structured side facing the exterior of said optical cavity, said structured surface having a plurality of triangular prisms thereon, the axes of said prisms running parallel to the direction of said support column; a translucent layer overlying said transparent film; and a beam spreader for dispersing light entering said optical cavity from said support column.
Claim 2
Dependent Claim
127 words
An elevated, back-lit display having a support column and means defining an optical cavity having an optical window on top of said support column, said display characterized in that it further comprises: a light source and a light conduit in said support column, said light source being positioned to emit light into said light conduit; a transparent film having a smooth side and a structured side positioned in said optical window, said structured side facing the exterior of said optical cavity, said structured surface having a plurality of triangular prisms thereon, the axes of said prisms running parallel to the direction of said support column; a translucent layer overlying said transparent film; and a beam spreader for dispersing light entering said optical cavity from said support column.
Claim 3
Dependent Claim
40 words
The display of Claim 1 wherein beam spreader comprises a transparent film having a smooth side and a structured side, said structured side having a plurality of triangular prisms thereon, said structured side facing the interior of said optical cavity.
Claim 4
Dependent Claim
52 words
The display of Claim 1 wherein said light conduit comprises a film having a smooth surface and a structured surface, said structured surface having a plurality of triangular prisms thereon, said structured surface being on the exterior of said light conduit, the axes of said prisms running parallel to said support column.
Claim 5
Dependent Claim
70 words
The display of Claim 1 further comprising: means defining a second optical cavity having an optical window, said second optical cavity adjacent and in optical communication with said first optical cavity; a transparent film having a smooth surface and a structured surface in said second optical cavity optical window, said structured surface having thereon a plurality of triangular prisms, said structured surface facing the exterior of said second optical cavity.
Claim 6
Dependent Claim
20 words
The display of Claim 4 further comprising light diffusing means between said first optical cavity and said second optical cavity.
Claim 7
Dependent Claim
35 words
The display of Claim 1 wherein a least a portion of the interior of said support column is coated with light absorbing means in the region of said support column closest to said optical cavity.
References Cited (Backward Citations)
No citation records indexed.
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