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:
Jun. 29, 2010
Filed:
Sep. 26, 2007
Toshihiko Baba, Yokohama, JP;
Takuya Kazama, Tokyo, JP;
Junichi Sonoda, Tokyo, JP;
Stanley Electric Co., Ltd., Tokyo, JP;
Abstract
A light emitting device with an increased light extraction efficiency includes a two-dimensional periodic structure in a surface thereof and has two layers that together form an asymmetric refractive index distribution with respect to the active layer, which is in between the two layers. The light emitting device includes a substrate layer, a first layer, an active layer and a second layer that are stacked sequentially. The first layer includes at least one layer, including a semiconductor cladding layer of a first conductivity type. At least one layer of the first layer has a refractive index that is lower than a refractive index of the active layer and lower than a refractive index of a layer of the second layer that is adjacent to the active layer. Each constituent layer of the second layer has a refractive index that is lower than the refractive index of the active layer.