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:
Oct. 14, 2014
Filed:
Jun. 28, 2011
Masahiro Ide, Osaka, JP;
Motoyuki Oniki, Osaka, JP;
Tomoyuki Ichiza, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
Provided are an LED control device and a liquid crystal display apparatus, wherein energy loss or noise (humming sound) to be generated upon switching the control of power supplying from a power supply device to a plurality of LED groups, between constant current control and constant voltage control, can be alleviated. In a configuration wherein power to be supplied from one power supply device, to which a plurality of LED groups are connected in parallel, is controlled with constant current control wherein the voltage at the end section at the cathode side of the LED group to be turned on is to be maintained at a predetermined first voltage value, when at least one of the LED groups is to be turned on, and controlled with constant voltage control wherein the voltage at the end sections at the anode side of the LED groups is to be maintained at a predetermined second voltage value, when all the LED groups are to be turned off, a phase difference of 2π/n (n is the number of LED groups) is made to be generated between PWM signals corresponding to each of the LED groups.