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:
Jan. 15, 2019
Filed:
Mar. 12, 2014
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Hiroshi Ohno, Kanagawa-ken, JP;
Yuichiro Yamamoto, Kanagawa-ken, JP;
Mitsuaki Kato, Kanagawa-ken, JP;
Tomonao Takamatsu, Kanagawa-ken, JP;
Masataka Shiratsuchi, Kanagawa-ken, JP;
Hiromichi Hayashihara, Saitama-ken, JP;
Hideo Tamura, Kanagawa-ken, JP;
Masahiko Yamamoto, Kanagawa-ken, JP;
KABUSHIKI KAISHA TOSHIBA, Minato-ku, JP;
Abstract
In one embodiment, an illumination device includes a light-guiding unit having a light output surface which outputs light and a back surface facing the light output surface, wherein the light-guiding unit has a curved surface in a region of the back surface farther than a first position on the back surface that is away by a first distance from an axis passing the light output surface and the back surface, and a rough surface in a region of the light output surface farther than a second position on the light output surface that is away by a second distance from the axis in a same direction as a direction from the axis toward the first position, and where an intersection of the axis and the back surface is an origin point, and a direction of the axis from the back surface to the light output surface is positive, a normal line of the curved surface intersects with the axis at the positive side of the axis, and an angle formed by a normal line vector at the second position in a direction toward the light output surface from the back surface of the light output surface and a vector in a direction from the curved surface to the second position is equal to or more than a critical angle.