Title:
LED制御装置,液晶表示装置
Document Type and Number:
Japanese Patent JP4922439
Kind Code:
B2
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 2n/n (n is the number of LED groups) is made to be generated between PWM signals corresponding to each of the LED groups.
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Inventors:
Masahiro Ide
Motoyuki Oniki
Tomoyuki Ichiza
Motoyuki Oniki
Tomoyuki Ichiza
Application Number:
JP2010151163A
Publication Date:
April 25, 2012
Filing Date:
July 01, 2010
Export Citation:
Assignee:
Sharp Corporation
International Classes:
H01L33/00; G02F1/13357; H05B37/02; H05B44/00
Domestic Patent References:
| JP2009032497A |
Attorney, Agent or Firm:
Hiroyuki Okada
Kazuyuki Tanemura
Kazuyuki Tanemura