Reflection plate, display device, and method of producing reflection plate
A reflection plate includes a substrate, an insulation film disposed on the substrate and including projection portions and recesses on an uneven surface, and a reflection film disposed on the uneven surface and having a surface that conforms to the uneven surface and reflecting light. The projection portions are arranged at intervals and are inclined with respect to a normal direction of a surface of the substrate. The recesses are between the projection portions that are adjacent to each other. The projection portions include a first projection portion, a second projection portion, and a third projection portion that are inclined in different directions.
1 . A reflection plate comprising:
a substrate;
an insulation film disposed on the substrate and having an uneven surface; and
a reflection film disposed in an upper layer above the insulation film and having a surface that conforms to the uneven surface, the reflection film reflecting light, wherein:
the insulation film includes projection portions and recesses on the uneven surface,
the recesses are between the projection portions that are adjacent to each other,
the projection portions are arranged at intervals,
the projection portions include a first projection portion, a second projection portion that is adjacent to and spaced apart from the first projection portion, and a third projection portion that is adjacent to and spaced apart from the first projection portion,
the first projection portion has a first center of gravity of a plan view outline of the first projection portion and a first top,
the first center of gravity and the first top do not correspond to each other in a plan view,
the second projection portion has a second center of gravity of a plan view outline of the second projection portion and a second top,
the second center of gravity and the second top do not correspond to each other in the plan view,
the third projection portion has a third center of gravity of a plan view outline of the third projection portion and a third top,
the third center of gravity and the third top do not correspond to each other in the plan view,
in the first projection portion, a line connecting the first center of gravity and the first top extends in a first direction,
in the second projection portion, a line connecting the second center of gravity and the second top extends in a second direction,
in the third projection portion, a line connecting the third center of gravity and the third top extends in a third direction,
the first direction, the second direction, and the third direction cross each other,
the recesses include first recessed portions and a second recessed portion,
the first recessed portions are adjacent to the plan view outlines of the first projection portion, the second projection portion, and the third projection portion, respectively,
the first recessed portions are deeper than the second recessed portion, and
the first recessed portions are, respectively, closer to the first top, the second top, and the third top than the first center of gravity, the second center of gravity, and the third center of gravity are.
2 . The reflection plate according to claim 1 , wherein the first direction, the second direction, and the third direction include an upward vector component with respect to a vertical direction.
3 . The reflection plate according to claim 2 , wherein:
the substrate has a rectangular plan view shape and includes a first side that extends along the vertical direction and a second side that extends along a horizontal direction,
a length of the first side is defined as A,
a length of the second side is defined as B,
an angle between the first direction and an upward direction, with respect to the vertical direction, is defined as θ 1 ,
an angle between the second direction and the upward direction, with respect to the vertical direction, is defined as θ 2 ,
an angle between the third direction and the upward direction, with respect to the vertical direction, is defined as θ 3 , and
the first projection portion, the second projection portion, and the third projection portion are configured, such that the angles θ 1 , θ 2 , and θ 3 satisfy the following formula:
−arctan( B/A )≤θ1,θ2,θ3≤arctan( B/A ).
4 . The reflection plate according to claim 3 , wherein at least one of the angles θ 1 , θ 2 , or θ 3 is equal to a value obtained from −arctan (B/A) or arctan (B/A).
5 . A display device comprising:
the reflection plate according to claim 1 ; and
an opposed substrate that is disposed opposite the reflection plate.
6 . The display device according to claim 5 , further comprising:
a liquid crystal layer that is held between the reflection plate and the opposed substrate.
7 . The reflection plate according to claim 6 , further comprising:
a backplane circuit disposed on the substrate;
an insulation layer; and
a transparent electrode disposed on the insulation layer, wherein:
the insulation film having the uneven surface covers the backplane circuit, and
the insulation layer covers the reflection film.
8 . The reflection plate according to claim 1 , wherein a first one of the first recessed portions is adjacent to a portion of a basal portion of the first projection portion, and the basal portion has the plan view outline of the first projection portion.
9 . The reflection plate according to claim 8 , wherein:
the plan view outline of the first projection is circular, and
the first one of the first recessed portions extends along the portion of the plan view outline of the first projection portion and has an arched plan view shape having a predefined width.
10 . The reflection plate according to claim 9 , wherein:
the plan view outline of the second projection and the plan view outline of the third projection are circular,
a second one of the first recessed portions is adjacent to a portion of the plan view outline of the second projection portion, extends along the portion of the plan view outline of the second projection portion, and has an arched plan view shape having a predefined width, and
a third one of the first recessed portions is adjacent to a portion of the plan view outline of the third projection portion, extends along the portion of the plan view outline of the third projection portion, and has an arched plan view shape having a predefined width.
11 . The reflection plate according to claim 8 , wherein:
a shape of the plan view outline of the first projection portion includes a first arched portion and a first straight portion that extends between two ends of the first arched portion, and
the first one of the first recessed portions is adjacent to the first straight portion and has a linear plan view shape having a predefined width.
12 . The reflection plate according to claim 11 , wherein:
a shape of the plan view outline of the second projection portion includes a second arched portion and a second straight portion that extends between two ends of the second arched portion,
a second one of the first recessed portions is adjacent to the second straight portion and has a linear plan view shape having a predefined width,
a shape of the plan view outline of the third projection portion includes a third arched portion and a third straight portion that extends between two ends of the third arched portion, and
a third one of the first recessed portions is adjacent to the third straight portion and has a linear plan view shape having a predefined width.
13 . The reflection plate according to claim 8 , wherein:
a shape of the plan view outline of the first projection portion includes two arched portions that have different curvature radiuses, and
the first one of the first recessed portions is adjacent to one of the two arched portions and has an arched plan view shape having a predetermined width.
14 . The reflection plate according to claim 13 , wherein:
a shape of the plan view outline of the second projection portion includes two arched portions that have different curvature radiuses,
a second one of the first recessed portions is adjacent to one of the two arched portions of the second projection portion and has an arched plan view shape having a predetermined width,
a shape of the plan view outline of the third projection portion includes two arched portions that have different curvature radiuses, and
a third one of the first recessed portions is adjacent to one of the two arched portions of the third projection portion and has an arched plan view shape having a predetermined width.