The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 09, 2012
Filed:
Jun. 04, 2009
Osamu Yoshimura, Chiyoda-ku, JP;
Tatsuya Ueda, Tainai, JP;
Osamu Yoshimura, Chiyoda-ku, JP;
Tatsuya Ueda, Tainai, JP;
Kuraray Co., Ltd., Kurashiki-shi, JP;
Abstract
An object of the present invention is to provide a decorative illumination signboard capable of effectively downwardly emitting light while suppressing an upward emission of light with a simple configuration and a plastic sheet used in the decorative illumination signboard. The object can be accomplished by a plastic sheet having optical transparency which includes an exit surface and an incident surface on which a plurality of prism lines having a flat and smooth surface are arranged to be aligned. A shape of the prism in a cross-section perpendicular to a longitudinal direction of the prism line is formed by a side A on a lower side at an angle of α degrees to a normal line of the exit surface and a side B on an upper side at an angle of β degrees to the normal line of the exit surface and α<β, and 40 degrees≦β≦80 degrees. An integral value of a downwardly emitted light flux is 55% or more of the total integral value of an upwardly emitted light flux and the downwardly emitting light flux when predetermined diffusion light enters one surface of the plastic sheet in a direction perpendicular to the plastic sheet.