EP0390344A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Retroreflective articles having light-transmissive surfaces
Assignee: 3M Co
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Filing: 1990-03-02
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Granted: —
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Expires: 2010-03-02
Abstract
Abstract Retroreflective elements, such as cube-corner elements or right triangular prisms containing cube-corners, are arranged on articles to define separation surfaces between the elements; in another embodiment, the elements are truncated cube-corners incorporating similar surfaces on the elements themselves. If the surfaces are transparent they will transmit light through the article, rendering it partially transparent and partially retroreflective. The surfaces may be flat or curved. Standard grooving techniques may be employed to construct the elements, using mold cutting tools having flattened or curved tips instead of V-shaped tips; alternatively, electroformed molds may be lapped to include the shape required to produce surfaces. The elements and surfaces may be embodied in sheeting materials or internally illuminated signs.
Inventors
- 👤 Gerald M. Benson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 21:06
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/12; G02B5/122; G02B5/124
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
103 words
A partially transparent retroreflective article formed by three intersecting sets of parallel grooves, comprising a base, prismatic elements having lateral faces intersecting the base at base edges, and separation surfaces on the base, in which: (a) each set of grooves has a groove side angle that is constant for that set; and (b) the separation surfaces are transparent, are bounded by the base edges of the lateral faces of the prismatic elements, lie between the prismatic elements in at least one of the grooves, have, taken at any point along any groove in which they lay, curved cross sections taken across that groove.
Claim 2
Dependent Claim
103 words
A partially transparent retroreflective article formed by three intersecting sets of parallel grooves, comprising a base, prismatic elements having lateral faces intersecting the base at base edges, and separation surfaces on the base, in which: (a) each set of grooves has a groove side angle that is constant for that set; and (b) the separation surfaces are transparent, are bounded by the base edges of the lateral faces of the prismatic elements, lie between the prismatic elements in at least one of the grooves, have, taken at any point along any groove in which they lay, curved cross sections taken across that groove.
Claim 3
Dependent Claim
21 words
The article of claim 1 in which the base edges of the lateral faces of the elements form substantially isosceles triangles.
Claim 4
Dependent Claim
21 words
The article of claim 2 in which the base edges of the lateral faces of the elements form substantially equilateral triangles.
Claim 5
Dependent Claim
31 words
The article of claim 2 in which the base edges of the lateral faces of the elements form triangles having included angles of substantially 65 degrees, 65 degrees, and 50 degrees.
Claim 6
Dependent Claim
60 words
The article of claim 2 in which the prismatic elements are rotated 180° with respect to one another, the lateral faces of each element are mutually perpendicular and defined at their bases by linear base edges that lie in a common plane, and the optical axes of each element of the pair are tilted towards one edge of that element.
Claim 7
Dependent Claim
17 words
The article of claim 1 in which a lateral face of a prismatic element is specularly reflective.
Claim 8
Dependent Claim
23 words
A polymeric sheet material having on one large area side an array of prismatic elements and separation surfaces as defined in claim 1.
Claim 9
Dependent Claim
39 words
An internally illuminated sign comprising an enclosure transmissive to light on at least one side, designated the front side, and the cube corner retroreflective sheeting of claim 7 positioned to reflect light incident on the front of the sign.
Claim 10
Dependent Claim
170 words
A partially transparent retroreflective article formed by three intersecting sets of parallel grooves, comprising a base, prismatic elements having lateral faces intersecting the base at base edges of a base edge length, and separation surfaces on the base, in which: (a) each set of grooves has a groove side angle that is constant for that set; (b) the separation surfaces are transparent, are bounded by the base edges of the lateral faces of the prismatic elements, lie between the prismatic elements in at least one of the grooves, have, taken at any point along any groove in which they lay, flat cross sections taken across that groove; (c) the elements are not rotated 180° with respect to one another with optical axes of each element of the pair tilted towards one edge of that element; and (d) the separation surfaces have ratios of base edge length to separation surface width, as measured at any point along any groove at which the cross section is flat, which do not exceed 24.7.
Claim 11
Dependent Claim
170 words
A partially transparent retroreflective article formed by three intersecting sets of parallel grooves, comprising a base, prismatic elements having lateral faces intersecting the base at base edges of a base edge length, and separation surfaces on the base, in which: (a) each set of grooves has a groove side angle that is constant for that set; (b) the separation surfaces are transparent, are bounded by the base edges of the lateral faces of the prismatic elements, lie between the prismatic elements in at least one of the grooves, have, taken at any point along any groove in which they lay, flat cross sections taken across that groove; (c) the elements are not rotated 180° with respect to one another with optical axes of each element of the pair tilted towards one edge of that element; and (d) the separation surfaces have ratios of base edge length to separation surface width, as measured at any point along any groove at which the cross section is flat, which do not exceed 24.7.
Claim 12
Dependent Claim
30 words
The article of claim 9 in which the separation surfaces are at least 0.0051 mm in width at any point along any groove at which the cross section is flat.
Claim 13
Dependent Claim
21 words
The article of claim 9 in which the base edges of the lateral faces of the elements form substantially isosceles triangles.
Claim 14
Dependent Claim
21 words
The article of claim 11 in which the base edges of the lateral faces of the elements form substantially equilateral triangles.
Claim 15
Dependent Claim
31 words
The article of claim 11 in which the base edges of the lateral faces of the elements form triangles having included angles of substantially 65 degrees, 65 degrees, and 50 degrees.
Claim 16
Dependent Claim
17 words
The article of claim 9 in which a lateral face of a prismatic element is specularly reflective.
Claim 17
Dependent Claim
23 words
A polymeric sheet material having on one large area side an array of prismatic elements and separation surfaces as defined in claim 9.
Claim 18
Dependent Claim
39 words
An internally illuminated sign comprising an enclosure transmissive to light on at least one side, designated the front side, and the cube corner retroreflective sheeting of claim 15 positioned to reflect light incident on the front of the sign.
Claim 19
Dependent Claim
49 words
A partially transparent retroreflective article comprising a base and prismatic elements formed on the base, in which: the elements are truncated cube-corner elements having lateral faces, base edges, elevated edges, and truncated surfaces; and the truncated surfaces are transparent and bounded by the elevated edges of the prismatic elements.
Claim 20
Dependent Claim
49 words
A partially transparent retroreflective article comprising a base and prismatic elements formed on the base, in which: the elements are truncated cube-corner elements having lateral faces, base edges, elevated edges, and truncated surfaces; and the truncated surfaces are transparent and bounded by the elevated edges of the prismatic elements.
Claim 21
Dependent Claim
15 words
The article of claim 17 in which the truncated elements are truncated full cube-corner elements.
Claim 22
Dependent Claim
28 words
The article of claim 17 in which the truncated elements are truncated pyramids having triangular bases formed by the base edges of the lateral faces of the elements.
Claim 23
Dependent Claim
21 words
The article of claim 19 in which the base edges of the lateral faces of the elements form substantially isosceles triangles.
Claim 24
Dependent Claim
21 words
The article of claim 20 in which the base edges of the lateral faces of the elements form substantially equilateral triangles.
Claim 25
Dependent Claim
31 words
The article of claim 20 in which the base edges of the lateral faces of the elements form triangles having included angles of substantially 65 degrees, 65 degrees, and 50 degrees.
Claim 26
Dependent Claim
17 words
The article of claim 17 in which a lateral face of a prismatic element is specularly reflective.
Claim 27
Dependent Claim
23 words
A polymeric sheet material having on one large area side an array of prismatic elements and truncated surfaces as defined in claim 17.
Claim 28
Dependent Claim
39 words
An internally illuminated sign comprising an enclosure transmissive to light on at least one side, designated the front side, and the cube corner retroreflective sheeting of claim 24 positioned to reflect light incident on the front of the sign.
Claim 29
Dependent Claim
60 words
A partially transparent retroreflective article comprising: a base, and prismatic elements formed on the base which are substantially right triangular prisms having mutually approximately parallel right triangular end faces and mutually approximately perpendicular lateral faces approximately perpendicular to the end faces; in which transparent separation surfaces are bounded by the base edges of the lateral faces of the prismatic elements.
Claim 30
Dependent Claim
60 words
A partially transparent retroreflective article comprising: a base, and prismatic elements formed on the base which are substantially right triangular prisms having mutually approximately parallel right triangular end faces and mutually approximately perpendicular lateral faces approximately perpendicular to the end faces; in which transparent separation surfaces are bounded by the base edges of the lateral faces of the prismatic elements.
Claim 31
Dependent Claim
31 words
The article of claim 26 in which the prismatic elements are right triangular prisms having mutually parallel right triangular end faces and mutually perpendicular lateral faces perpendicular to the end faces.
Claim 32
Dependent Claim
24 words
The article of claim 26 in which the prismatic elements are right triangular prisms having right isosceles triangular end faces and rectangular lateral faces.
Claim 33
Dependent Claim
19 words
The article of claim 26 in which a lateral face of at least one prismatic element is specularly reflective.
Claim 34
Dependent Claim
23 words
A polymeric sheet material having on one large area side an array of prismatic elements and separation surfaces as defined in claim 26.
Claim 35
Dependent Claim
39 words
An internally illuminated sign comprising an enclosure transmissive to light on at least one side, designated the front side, and the cube corner retroreflective sheeting of claim 25 positioned to reflect light incident on the front of the sign.
References Cited (Backward Citations)
No citation records indexed.
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