Retroreflective articles having light-transmissive surfaces
First Claim
1. 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 surfacesare 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; and
(c) the separation surfaces have ratios of base edge length to separation surface width, as measured at any point along any groove, which do not exceed 24.7.
1 Assignment
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Accused Products
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.
210 Citations
16 Claims
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1. 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:
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(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, curved cross sections taken across that groove; and (c) the separation surfaces have ratios of base edge length to separation surface width, as measured at any point along any groove, which do not exceed 24.7. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. 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:
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(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; and (c) 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. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification