LIGHT REFLECTION PLATE AND BACKLIGHT UNIT

• Main Authors: KOKUBO YOSUKE, MORITA NAGAYUKI
• Format: Patent
• Language: English
• Published: 01.11.2012
• Subjects: BLASTING; 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-PORTABLE LIGHTING DEVICES; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

PROBLEM TO BE SOLVED: To provide a light reflection plate capable of responding to recent displays which are made to be thinner and made of thermoplastic polyester foam capable of achieving high luminance.SOLUTION: A light reflection plate for a backlight unit is made of polyester foam, and includes fine air bubbles having an average bubble diameter equal to or less than 50 μm therein, and its reflection surface side has arithmetic average surface roughness equal to or less than 1.2 μm. Preferably, the light reflection plate is obtained by cutting a fine air bubble layer of a base material including the fine air bubble layer and skin layers on both sides thereof at a cutting surface perpendicular to the thickness direction. Furthermore, preferably, a luminance difference ΔL (≡Ls-Lo) which is a difference between luminance Ls of a surface of the light reflection plate on the cutting surface side and luminance Lo of a surface of the light reflection plate on the opposite side of the cutting surface is equal to or greater than 10 cd/m.