Mitsubishi Electric Corporation

Nami Nakano

Shuichi Kagawa

Rena Nishitani

Kuniko Kojima

Muneharu Kuwata

Tomohiro Sasagawa

Nobutaka Kobayashi

A planar light source deviceincludes a light sourceand a reflection member. The light sourceemits a light beamhaving directivity. The reflection memberhas a box shape including a single bottom-plate part, side-plate partsandconnected to the bottom-plate part, and an opening partfacing the bottom-plate part. The box shape has inner surfaces which are reflection surfaces. The bottom-plate parthas a quadrilateral shape including two facing short sides and two facing long sides. The light beamenters an inside of the box shape of the reflection memberthrough a side of the side-plate partconnected to the short side of the bottom-plate part, travels in a direction of the long side of the bottom-plate partwhile being reflected at the side-plate partsandconnected to the long sides of the bottom-plate part, and is emitted through the opening part. The reflection surfaces of the side-plate partsandconnected to the long sides of the bottom-plate partinclude regions at which the light beamis specularly reflected and regions at which the light beamis diffused and reflected.

Planar light source device and liquid crystal display apparatus

An angular intensity distribution shaping member includes a first surface for receiving a light beam emitted from a light source, the first surface having a length in a width direction that is longer than that in a thickness direction; second surfaces forming a plate-shaped light path on which the light beam incident from the first surface propagates by total reflection, the second surfaces including at least one adjustment surface for spreading a full angle of an angular intensity distribution, in the width direction, of the light beam incident from the first surface so that the full angle becomes wider than that of the angular intensity distribution of the light beam just after emission from the light source; and a third surface through which the light beam exits, the full angle of its angular intensity distribution in the width direction having been widened by the at least one adjustment surface.

Surface light source device and liquid crystal display device

A surface light source device includes a surface light-emitting light-guiding unit; an LED light source disposed at an outside position on a side of a direction of the light incident surface; a plurality of laser light sources disposed at an outside position on a side of a direction of a rear surface of the surface light-emitting light-guiding unit; and a laser-light-ray guiding unit arranged on a side of a rear surface of the surface light-emitting light-guiding unit. The laser-light-ray guiding unit guides the laser light rays emitted from the laser light sources so that the laser light rays enter through a light incident end surface, travel in a direction opposite to a direction in which the LED light source emits the LED light ray, and thereafter are reflected by a light bending part to enter through the light incident surface of the surface light-emitting light-guiding unit.

Surface light source device and liquid crystal display apparatus

There are provided a light source () having a plurality of light emitters, each of the light emitters, whose light-emission period is controlled separately, emitting one color of a plurality of colors; an image signal analyzer for analyzing an input image data, and determining a timing of light emission for each light emitter; a light source controller () for controlling the light-emission period for the light source based on the light-emission timing for each light emitter, such that the light-emission period is not shorter than a light-emission period of a predetermined minimum time length light-emission period; a light detector () for detecting the light emitted in the light-emission period of the minimum time length, and outputting the average light-emission peak values (Ir, Ig, Ib); and a peak value corrector () for generating correction values (d_Ir, d_Ig, d_Ib) for controlling each of the average light-emission peak values (Ir, Ig, Ib) to become equal to corresponding one in the reference peak values (tIr, tIg, tIb) stored in a memory (). Even when the light-emission period is changed according to the input image, the color balance of the image is maintained constant.

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Tokyo, Japan

Nami Nakano