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. 07, 2018
Filed:
Apr. 08, 2016
Citizen Watch Co., Ltd., Nishitokyo-shi, Tokyo, JP;
Citizen Electronics Co., Ltd., Yamanashi, Tokyo, JP;
Takashi Akiyama, Sayama, JP;
CITIZEN WATCH CO., LTD., Tokyo, JP;
CITIZEN ELECTRONICS CO., LTD., Yamanashi, JP;
Abstract
The LED drive circuit has a rectifying circuit that rectifies an alternating-current voltage, an LED string including a plurality of LEDs connected in series, a first switch whose one end is connected to a cathode of an LED in a last stage of the LED string, a capacitor whose one end is connected to the other end of the first switch, a second switch that is connected between one end of the capacitor and the anode of the LED in the first stage of the LED string, and a third switch that is connected between the cathode of the LED in the last stage of the LED string and a second terminal of the rectifying circuit, and which turns on when the full-wave rectified voltage is lower than a charge start voltage and turns off when the full-wave rectified voltage is higher than or equal to the charge start voltage.