Illuminating device and display

摘要

An illuminating device includes a light source which outputs light, a light guide member having an incident surface on which the light from the light source is incident, an output surface through which the light is output from the light guide member, and a light deflection surface on which light deflection elements are formed such that the light is guided toward the output surface, and an isotropic light diffusion member positioned over the output surface of the light guide member. The light guide member has the incident surface extended in an X direction and includes a unit lens formed on the output surface and extended in a Y direction orthogonal to the X direction. A light-deflection element density D representing a number of the light deflection elements per unit area increases as the light deflection elements are positioned farther away from the incident surface.

主权项

1. An illuminating device, comprising:
a light source configured to output light; a light guide member having an incident surface on which the light from the light source is incident, an output surface through which the light is output from the light guide member, and a light deflection surface on which a plurality of light deflection elements are formed such that the light is guided toward the output surface; and an isotropic light diffusion member positioned over the output surface of the light guide member, wherein the light guide member has the incident surface extended in an X direction and includes a unit lens formed on the output surface and extended in a Y direction orthogonal to the X direction, the light deflection elements are positioned such that a light-deflection element density D representing a number of the light deflection elements per unit area increases as the light deflection elements are positioned farther away from the incident surface, the light deflection elements are formed in a pattern which is divided into a plurality of regions in the Y direction and are positioned in one of the regions such that a pitch Lx in the X direction is substantially constant, and that adjacent light deflection elements in the Y direction are shifted from each other in the X direction by a half of the pitch Lx and have a pitch Ly in the Y direction which becomes shorter as the light deflection elements are positioned farther away from the incident surface, Gx, Gy, β, γ, and θ are defined by following formulae (1), and Lx and Ly satisfy following formulae (2) in one of the regions which is adjacent to the incident surface:Gx=HL⁢tan⁡(θ-β)+ax2Gy=HL⁢tan⁢⁢γ+ay2β=sin-1⁡(sin⁡(θ-α)NL)γ=sin-1⁡(sin⁢⁢αNL)θ=tan-1⁡[10P⁢∫01/10⁢P⁢ⅆf⁡(t)ⅆt⁢ⅆt]}(1)2⁢ax≤Lx≤4⁢Gx2⁢ay≤Ly≤4⁢Gy2⁢SdLx⁢Ly≥0.01}(2)where HL represents a thickness of the light guide member,
NL represents a refractive index of the light guide member, Sd represents an area of one of the light deflection elements when viewed from a side of the light deflection surface, t represents a measured displacement in the X direction when an end of the unit lens is set to 0, f(t) represents a distance between an edge of the unit lens and the output surface of the light guide member when the unit lens is taken along a plane orthogonal to the output surface and parallel to the X direction, P represents a pitch of the unit lens, α represents an angle at which an intensity of an output light generated by a collimate light incident orthogonally to the isotropic light diffusion member becomes one tenth of a maximum intensity thereof in an angular distribution of the output light, ax represents a width of each of the light deflection elements in the X direction, and ay represents a width of each of the light deflection elements in the Y direction.