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:
Dec. 26, 2023
Filed:
Jan. 25, 2022
Epistar Corporation, Hsinchu, TW;
Heng-Ying Cho, Hsinchu, TW;
De-Shan Kuo, Hsinchu, TW;
EPISTAR CORPORATION, Hsinchu, TW;
Abstract
A light-emitting device includes a substrate having a first surface and a second surface opposite to the first surface; a light-emitting stack formed on the first surface; and a distributed Bragg reflection structure formed on the second surface, wherein the distributed Bragg reflection structure includes a first film stack and a second film stack; wherein the first film stack includes a plurality of first dielectric-layer pairs consecutively arranged, the second film stack includes a plurality of second dielectric-layer pairs consecutively arranged, each of the first dielectric-layer pairs and each of the second dielectric-layer pairs respectively includes a first dielectric layer having an optical thickness and a second dielectric layer having an optical thickness; wherein the second dielectric layer has a refractive index higher than that of the first dielectric layer; wherein in each of the first dielectric-layer pairs of the first film stack, the optical thickness of the first dielectric layer to the optical thickness of the second dielectric layer have a first ratio, and in each of the second dielectric-layer pairs of the second film stack, the optical thickness of the first dielectric layer to the optical thickness of the second dielectric layer have a second ratio; wherein the first ratio is greater than the second ratio; and wherein the first film stack is farther from the second surface of the substrate than the second film stack.