EP0225123A2
Expired / Lapsed
EP
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A totally internally reflecting thin, flexible film
Assignee: 3M Co
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Filing: 1986-11-19
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Granted: —
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Expires: 2006-11-19
Abstract
Abstract A thin, flexible film made of a transparent polymeric material including a structured surface and an opposite smooth surface, wherein light striking either surface, within certain angular ranges, is totally internally reflected. The structured surface includes a linear array of miniature substantially right angled isosceles prisms arranged side-by-side to form a plurality of peaks and grooves. In addition, the perpendicular sides of the prisms make an angle of approximately 45° with the smooth surface, and when the film is curled the smooth surface lies in a smooth continuous arcuate curve without materially affecting the performance of the film. Because of the film's flexibility and its ability to totally internally reflect light, it may be utilized in a variety of ways, for example, as a collector of solar energy or as a light conduit. The performance of the film may be manipulated to permit controlled light leakage.
Inventors
- 👤 Sanford Jr. C/O Minnesota Mining And Cobb
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 16:24
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; F; F21; F21V; F21V5/00; F21V5/002; F24; F24S; F24S23/00; F24S23/10; G02B5/00; G02B5/12; F21V2200/00; F21V2200/40; G02B6/24; G02B6/36; G02B6/38; G02B6/3807; Y; Y02; Y02E; Y02E10/00; Y02E10/40
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
103 words
A thin, flexible film formed of a transparent polymeric material, comprising a structured surface on one side and a smooth surface opposite said structured surface on the other side characterized in that said structured surface (12) includes a linear array of miniature substantially right angled isosceles prisms (16) arranged side-by-side to form a plurality of peaks (17) and grooves (18), the perpendicular sides (20) of said prisms (16) make an angle of approximately 45° with said smooth surface (14) opposite said structured surface (12), so that when said film 10) is curled said smooth surface (14) lies in a smooth continuous arcuate curve.
Claim 2
Dependent Claim
103 words
A thin, flexible film formed of a transparent polymeric material, comprising a structured surface on one side and a smooth surface opposite said structured surface on the other side characterized in that said structured surface (12) includes a linear array of miniature substantially right angled isosceles prisms (16) arranged side-by-side to form a plurality of peaks (17) and grooves (18), the perpendicular sides (20) of said prisms (16) make an angle of approximately 45° with said smooth surface (14) opposite said structured surface (12), so that when said film 10) is curled said smooth surface (14) lies in a smooth continuous arcuate curve.
Claim 3
Dependent Claim
24 words
The film defined in claim 1, further characterized in that said isosceles prisms (16) are micro in size, at least 40 per 2.5 cm.
Claim 4
Dependent Claim
21 words
The film defined in claim 1, further characterized in that the film (10) does not have sufficient strength to be self-supporting.
Claim 5
Dependent Claim
16 words
The film defined in claim 1, further characterized in that said transparent polymeric material is polycarbonate.
Claim 6
Dependent Claim
16 words
The film defined in claim 1, further characterized in that said transparent polymeric material is acrylic.
Claim 7
Dependent Claim
25 words
The film defined in claim 1, further characterized in that incident light striking the smooth surface (14) within certain angular ranges is totally internally reflected.
Claim 8
Dependent Claim
25 words
The film defined in claim 1, further characterized in that incident light striking the structured surface (12) within certain angular ranges is totally internally reflected.
Claim 9
Dependent Claim
51 words
The film defined in claim 1, further characterized in that said film (10) has a thickness of approximately 0.38 mm and about 70 prisms (16) per 2.5 cm so that when said film (10) is curled said smooth surface (14) lies in a smooth continuous arcuate curve without any discernable discontinuities.
Claim 10
Dependent Claim
48 words
The film defined in claim 1, further characterized in that said peaks (17 & 17') are rounded to permit controlled light leakage defined in accordance with the ratio r/p, where r is the approximate radius of the round peaks (17 & 17') and p is the groove period.
Claim 11
Dependent Claim
19 words
The film defined in claim 9, further characterized in that said transparent polymeric material further includes light diffusing particles.
Claim 12
Dependent Claim
133 words
A light conduit for transporting light, comprising a thin, flexible film of a transparent polymeric material including a structured surface on one side and a smooth surface opposite said structured surface on the other side characterized in that said structured surface (12) having a linear array of miniature substantially right angled isosceles prisms (16) arranged side-by-side to form a plurality of peaks (17) and grooves (18), the perpendicular sides (20) of said prisms (16) make an angle of approximately 45° with said smooth surface (14) opposite said structured surface (12), and said film (10) is formed into a tubular configuration so that said smooth surface (14) lies in a smooth continuous arcuate curve, whereby light entering the conduit (40), within certain angular ranges, is totally internally reflected as it travels along conduit (40).
Claim 13
Dependent Claim
133 words
A light conduit for transporting light, comprising a thin, flexible film of a transparent polymeric material including a structured surface on one side and a smooth surface opposite said structured surface on the other side characterized in that said structured surface (12) having a linear array of miniature substantially right angled isosceles prisms (16) arranged side-by-side to form a plurality of peaks (17) and grooves (18), the perpendicular sides (20) of said prisms (16) make an angle of approximately 45° with said smooth surface (14) opposite said structured surface (12), and said film (10) is formed into a tubular configuration so that said smooth surface (14) lies in a smooth continuous arcuate curve, whereby light entering the conduit (40), within certain angular ranges, is totally internally reflected as it travels along conduit (40).
Claim 14
Dependent Claim
57 words
The light conduit defined in claim 11, further characterized in that the corners of said prisms (16) of said structured surface (12) are not optically sharp, so that the light conduit (40) acts as an illuminator by allowing some of the light entering said conduit (40) to escape through the film (10) without being totally internally reflected.
Claim 15
Dependent Claim
58 words
The light conduit defined in claim 11, further characterized in that the perpendicular sides (20) of said prisms (16) of said structured surface (12) are not optically smooth, so that the light conduit (40) acts as an illuminator by allowing some of the light entering said conduit to escape through the film (10) without being totally internally reflected.
Claim 16
Dependent Claim
49 words
The light conduit defined in claim 11, further characterized in that said peaks (17 & 17') are rounded to permit controlled light leakage defined in accordance with the ratio r/p, where r is the approximate radius of the round peaks (17 & 17') and p is the groove period.
Claim 17
Dependent Claim
20 words
The light conduit defined in claim 11, further characterized in that said transparent polymeric material further includes light diffusing particles.
References Cited (Backward Citations)
No citation records indexed.
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