Optical element like corner cube retroreflector and reflective display device including such an optical element
AssigneeSharp Kabushiki Kaisha
InventorsKiyoshi Minoura, Shun Ueki, Masahiko Tomikawa
Life of this patent
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Abstract
An optical element includes first and second members. The first member has a first surface including a first concave portion. The second member has a second surface including a second concave portion and transmits incoming light therethrough. The first and second members are disposed so that the first and second surfaces are opposed to each other. First and second reflective regions have been formed on the first and second concave portions, respectively. At least part of the incoming light that has been transmitted through the second member is reflected from at least one of the first and second reflective regions.
Claims27
An optical element comprising:
- a first member, which has a first surface including a first concave portion;
- and
- a second member, which has a second surface including a second concave portion and which transmits incoming light therethrough, the first and second members being disposed so that the first and second surfaces are opposed to each other,
- wherein first and second reflective regions have been formed on the first and second concave portions, respectively, and
- wherein at least part of the incoming light that has been transmitted through the second member is reflected from at least one of the first and second reflective regions.
An array of corner cubes, each having three facets that are opposed substantially perpendicularly to each other, wherein each of the three facets of each said corner cube includes:
- a first surface of a concave portion that has been formed in a base member;
- and a second surface of a convex member that has been formed on the base member so as to be adjacent to the concave portion.
A method of making an optical element, comprising the steps of:
- forming a first concave portion in a first member and forming a first reflective region on the first concave portion;
- forming a second concave portion in a second member and forming a second reflective region on the second concave portion;
- and
- disposing the first and second members in such a manner that a surface of the first member in which the first concave portion has been formed is opposed to a surface of the second member in which the second concave portion has been formed.
A method of making a corner cube array, comprising the steps of:
- a) preparing a first member in which at least one first concave portion has been formed in a triangular pyramidal shape, the first concave portion being made up of three triangular facets that are opposed substantially perpendicularly to each other;
- b) preparing a second member in which at least one second concave portion has been formed in the triangular pyramidal shape, the second concave portion being made up of three triangular facets that are opposed substantially perpendicularly to each other;
- and
- c) disposing the first and second members in such a manner that a surface of the first member in which the first concave portion has been formed is opposed to a surface of the second member in which the second concave portion has been formed,
- wherein the corner cube array is made up of a plurality of cubic corner cubes, each of which comprises a first set of triangular planes defined by the first concave portion and a second set of triangular planes defined by the second concave portion.
A method of making a corner cube array, comprising the steps of:
- a) preparing a base member including a plurality of triangular pyramidal concave portions, each of which has three perpendicularly opposed equilateral triangular facets, in a predetermined surface thereof;
- and
- b) forming a plurality of triangular pyramidal convex members, each of which has three perpendicularly opposed equilateral triangular facets, on the predetermined surface of the base member.
A die for use to make a micro corner cube array comprises:
- a base member including a plurality of triangular pyramidal concave portions, each of which has three of perpendicularly opposed equilateral triangular facets, in a predetermined surface thereof;
- and
- a plurality of triangular pyramidal convex members, each of which has three perpendicularly opposed equilateral triangular facets, formed on the predetermined surface of the base member.
Dependencies are inferred from the claim text.