OPTICAL WAVEGUIDE FOR PREVENTING POOR EMITTING LIGHT FROM BEING GENERATED, AND AREA LIGHT SOURCE APPARATUS AND LCD HAVING THE SAME

• Main Authors: NIIDA, EIKI, KONOMA, TAKAAKI, TOEDA, MINORU, ISOGAI, FUMIKAZU, YAMAMOTO, NAOYUKI
• Format: Patent
• Language: English; Korean
• Published: 06.01.2005
• Edition: 7
• 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; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21Sand F21V, RELATING TO THEFORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THELIGHT EMITTED; LIGHTING; MECHANICAL ENGINEERING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; WEAPONS

PURPOSE: An optical waveguide is provided to receive light and effectively emit the received light to the front using a curved prism, thereby preventing poor light from being emitted. An area light source apparatus and an LCD, each having such an optical waveguide, are provided. CONSTITUTION: An optical waveguide(14) includes a first surface and a second surface(18). The first surface is positioned to oppose the second surface. A third surface(14a) connects the first surface with the second surface. The optical waveguide receives light through the third surface and emits the received light to the outside through the second surface. The first surface is provided with a plurality of grooves. Of the grooves, the first grooves(19) are defined by the sections of the first surface. The sections of the first surface respectively includes reflecting surfaces(19a,19b). The reflecting sections reflect incident light of the optical waveguide through the third surface upon the second surface. The extension direction of the reflecting surface is parallel with the third surface. The second surface is provided with a plurality of protrusions(curved prisms, 20) extended to cross the extension direction of the reflecting surface. Each protrusion has a peak line. The second grooves(21) are provided between the peak lines of the protrusions and are defined by the sections of the second surface between the peak lines. Each section of the second surface includes a bottom(21a) more adjacent to the first surface than a middle point of the second grooves in a depth direction.