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:
Aug. 20, 2013
Filed:
Aug. 31, 2009
Hyun Gu Kang, Ansan-si, KR;
Sang Min Lee, Ansan-si, KR;
Yoon Seok Lee, Ansan-si, KR;
Won IL Kim, Ansan-si, KR;
You Jin Kwon, Ansan-si, KR;
Hyun Gu Kang, Ansan-si, KR;
Sang Min Lee, Ansan-si, KR;
Yoon Seok Lee, Ansan-si, KR;
Won Il Kim, Ansan-si, KR;
You Jin Kwon, Ansan-si, KR;
Seoul Semiconductor Co., Ltd., Seoul, KR;
Abstract
A light emitting device comprises a first light emitting unit and a second light emitting unit connected in series with each other, and a PTF unit connected in parallel with the first light emitting unit and in series with the second light emitting unit. Each of the first light emitting unit and second light emitting unit comprises at least one LED. The PTF unit allows the second light emitting unit to be operated before operation of the first light emitting unit upon application of an AC voltage source. The light emitting device reduces total harmonic distortion and flickering, and improves power factor and optical efficiency. A driving circuit of the light emitting device is also disclosed.