Enplas Corporation

Toshihiko Mochida

Hiroshi Takatori

Hiroaki Okuyama

This light emitting device includes a light emitting element and a light flux controlling member. The light flux controlling member includes an incident surface, an emission surface, a back surface, a protruding portion and a scattering portion. In a cross section including a central axis, an angle formed by two beams, which are emitted from the light emitting device and have a maximum luminous intensity, is 150&#xb0; or more. In a cross section including a central axis, predetermined light is made incident at an incident angle of 60&#xb0; and an average angle, which is formed by, among the light reflected by the scattering portion, a light ray having a maximum light amount and a light ray having a light amount of 50% of the maximum light amount, is 5&#xb0; or more.

Light emitting device, surface light source device and display device

A light flux controlling member for controlling a distribution of light emitted from a light-emitting element includes an incidence surface configured to allow the light to enter the light flux controlling member; an emission surface configured to emit light; and a reflection part including an inclined surface configured to reflect light entered from the incidence surface, wherein in a cross-section, a region where light emitted from a light emission center of the light-emitting element that is entered from the incidence surface and sequentially reflected by the emission surface and the inclined surface reaches in the emission surface includes a portion where a derivative value of a gradient of a tangent to a given point in the emission surface is 0, or a portion where a sign of the derivative value reverses.

Light flux controlling member, light-emitting device, surface light source device and display device

A surface light source device includes a substrate, a plurality of light emitting devices and a light diffusion plate. Each light emitting device includes a light emitting element and a light flux controlling member. A cross section, perpendicular to the central axis of the light flux controlling member, of the emission surface is line-symmetric with respect to the X-axis and the Y-axis, and the cross section has the shortest length along the X-axis and the longest length along the Y-axis. For the light flux controlling member of one of the light emitting devices that is disposed closest to a corner of the light diffusion plate in plan view, a part having a largest curvature in the emission surface on the cross section of the emission surface is located closer to the X-axis than an intersection point of a light beam with the emission surface is.

Surface light source device and display device

This light flux control member comprises an incidence surface, an emission surface, and a plurality of protruding strips. The plurality of protruding strips are disposed approximately perpendicularly to a central axis. When the section perpendicular to the central axis of the incidence surface has the shape of an ellipse, at least some of the plurality of protruding strips are disposed outside a recessed part in the minor axis direction of the ellipse and along the minor axis direction. When the section of the emission surface has the shape of an ellipse, at least some of the plurality of protruding strips are disposed outside the recessed part in the major axis direction of the ellipse and along the major axis direction.

Light flux control member, light-emitting device, surface light source device and display device

The present invention provides a lens for a light emitting element (a luminous flux control member) that can ensure sufficient spread of light even with a smaller number of light emitting elements. The luminous flux control member () of the present invention includes: a dome shaped aspherical lens body (). The lens body () includes: a base surface (); and a dome shaped curved surface (). The base surface () has a base concave portion () centered on a central axis, a concave surface of the base concave portion () has a light incident region for incident light emitted from a light emitting element, the dome shaped curved surface () has a light emitting region for emitting incident light from the light incident region to an outside, the light emitting region of the curved surface () has an elliptical shape as viewed from a central axis direction centered on the central axis, in which a length (X) of an X axis orthogonal to the central axis and a length (Y) of a Y axis orthogonal to the central axis and the X axis satisfy X&#x3c;Y, the light emitting region of the curved surface has a pair of first concave portions () on both sides with the central axis interposed therebetween in a cross section including the X axis and the central axis, and the light emitting region of the curved surface has a second concave portion () on the central axis in a cross section including the Y axis and the central axis.

Luminous flux control member, light emitting device, surface light source device, and display device

This luminous flux control member has: a plane of incidence having a first incidence plane and a second incidence plane; an emission plane; and a second concavity. The luminous flux control member satisfies the expression h&#x3c;h+d&#xd7;cot(&#x3b8;), where his the space between the apex of the second concavity and a second imaginary line orthogonal to the center axis and that passes through the aperture edge portion, his the space between the second imaginary line and the incidence position of light on the second incidence plane, d is the distance between the incidence position and the apex in the direction orthogonal to the center axis, &#x3b8;is the angle of refraction of light in the incidence position, and &#x3b8;is the angle of the tangent line at the incidence position in relation to the second imaginary line.

Luminous flux control member, light-emitting device, planar light source device, and display device

The purpose of the present invention is to provide a light flux control member capable of suppressing brightness variation due to light refracted by an inclined surface. The light flux control member comprises: an entry surface which is an inner surface of a recess portion formed on a back side; an emission surface which is formed on a front side; and an annular groove portion which is formed on the back side and outside the entry surface. The annular groove portion includes an outside inclined surface and an inside surface. The inside surface includes a plurality of retroreflective portions.

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Saitama, Japan

Toshihiko Mochida