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. 30, 1990
Filed:
Mar. 03, 1988
Tomoaki Yoshida, Sendai, JP;
Fumio Inaba, Yagiyama-minami, Sendai-shi, Miyagi-ken, JP;
Hiromasa Ito, Aza-aoba, Aramaki, Sendai-shi, Miyagi-ken, JP;
Tetsuro Saito, Sendai, JP;
Shiro Sato, Ogawara, JP;
Junichi Azumi, Sendai, JP;
Other;
Ricoh Company, Tokyo, JP;
Abstract
A surface emission type semiconductor light-emitting device includes a base having a main surface, a current blocking layer formed on the base, and a semiconductor layer formed on the current blocking layer. A circular recess or hole having a side wall which is substantially perpendicular to the main surface is formed in the semiconductor layer as extending therethrough and partly into the base. An impurity is introduced into the semiconductor layer through the side wall and thus there is defined a cylindrical diffusion region around the recess. A p-n junction is defined at an outer boundary of the diffusion region and the p-n junction effectively defines a light-emitting activation region. An additional diffusion region may be formed in the semiconductor layer for narrowing a current path in the semiconductor layer. A second current blocking layer may be formed on top of the semiconductor layer. The semiconductor layer may have a multi-layer structure which may be constructed to provide a current confinement effect.