US 2011/0299270 A1 · OPTICAL SHEET, SURFACE LIGHT SOURCE DEVICE, TRANSMISSION TYPE DISPLAY DEVICE, LIGHT EMITTING DEVICE, MOLD AND MOLD PRODUCTION METHOD

Abstract

An optical sheet (30) includes a sheet-like body portion (32), and unit prisms (35) arranged on one surface (32a) of the body portion. Each unit prism (35) extends linearly in a direction intersecting the arrangement direction. Each unit prism, when viewed in a direction parallel to the arrangement direction of the unit prisms, has an uneven polygonal-line-shaped contour and, with reference to raised portions (37) defined by the polygonal-line-shaped contour of each unit prism, the distance between a top (37a) of each raised portion, a farthest point from the body portion in the raised portion, and the body portion in the normal direction of the body portion is not constant. The optical sheet can prevent significant problems when it is superimposed on another member.

Claims18

Dependent claims

An optical sheet comprising:

a sheet-like body portion;
and
unit prisms arranged on one surface of the body portion in an arrangement direction and each extending linearly in a direction intersecting the arrangement direction,
wherein each unit prism, when viewed in a direction parallel to the arrangement direction of the unit prisms, has an uneven polygonal-line-shaped contour, and wherein with reference to raised portions defined by the polygonal-line-shaped contour of each unit prism, a distance between a top of each raised portion, a farthest point from the body portion in the raised portion, and the body portion in a normal direction of the body portion is not constant.

1 more element

A mold for molding of an optical sheet having unit prisms, comprising a roll shaped mold having a circular cylindrical mold surface,

wherein at least one groove, corresponding to the unit prisms and extending spirally around a central axis of the mold surface, is formed in the mold surface,
wherein the depth of the groove changes in a polygonal-line manner along a longitudinal direction of the groove, with the bottom of the groove being uneven along the longitudinal direction of the groove, and
wherein a depth of the groove at the deepest point in each of recessed portions formed by the bottom of the groove is not constant.

Dependencies are inferred from the claim text.

Optical sheet, surface light source device, transmission type display device, light emitting device, mold and mold production method

Life of this patent

Optical sheet, surface light source device, transmission type display device, light emitting device, mold and mold production method

Life of this patent

Abstract

Claims18