SURFACE LIGHT SOURCE DEVICE AND DISPLAY DEVICE

• Main Authors: YAMADA KYOHEI, NONAKA AKIRA
• Format: Patent
• Language: English; Japanese
• Published: 18.04.2019
• Subjects: BLASTING; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; HEATING; LIGHTING; MECHANICAL ENGINEERING; NON-LINEAR OPTICS; NON-PORTABLE LIGHTING DEVICES; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

To provide a surface light source device which has high uniformity even when subjected to a reduction in thickness or an increase in size.SOLUTION: A surface light source device comprises a housing, a base plate, a plurality of light emitting devices and a light diffusion member. Each light emitting device has a light emitting element and a light flux control member. The housing has a bottom face with the base plate arranged thereon and two inclined faces which are respectively connected to sides of the bottom face in a direction perpendicular to an arrangement direction of the light emitting devices and come closer to the light diffusion member with the increase in distances from the bottom face. The light emitting devices have a light distribution characteristic of enabling a light beam having a largest angle with respect to a light axis, among an angle range with available luminosity of 70% of maximum luminosity or higher, to reach the inclined face. In a cross section perpendicular to the arrangement direction of the light emitting devices, a first angle between the light axis of the light emitting device and the light beam, with the maximum luminosity, emitted from the light emitting device is larger than a second angle between the light axis of the light emitting device and a line connecting a light emitting center of the light emitting device and an edge of the housing at the side of an opening section.SELECTED DRAWING: Figure 2 【課題】薄型化または大型化した場合であっても高い均斉度を有する面光源装置を提供すること。【解決手段】面光源装置は、筐体、基板、複数の発光装置および光拡散部材を有する。発光装置は、発光素子と、光束制御部材とを有する。筐体は、基板が配置された底面と、発光装置の配列方向に対して垂直な方向において、底面の両側にそれぞれ接続され、底面から離れるにつれて、光拡散部材に近づく２つの斜面とを有する。発光装置の配光特性において、最大光度の７０％以上の光度が示される角度範囲のうち光軸に対して最も大きな角度の光線は、斜面に到達する。発光装置の配列方向に対して垂直な断面において、発光素子の光軸と、発光装置から出射された最大光度の光線とのなす第１角度は、発光素子の光軸と、発光素子の発光中心と筐体の開口部側の端部とを繋ぐ直線とのなす第２角度より大きい。【選択図】図２