US 7,321,205 B2
Method and a controller to control power supply to a CCFL
Kuan-Hong Hsieh, Tu-Cheng (Taiwan)
Assigned to Hon Hai Precision Industry Co., Ltd., Tu-Cheng, Taipei Hsien (Taiwan)
Filed on Apr. 28, 2005, as Appl. No. 11/117,278.
Claims priority of application No. 2004 1 0027978 (CN), filed on Feb. 07, 2004.
Prior Publication US 2005/0200316 A1, Sep. 15, 2005
Int. Cl. G05F 1/00 (2006.01)
U.S. Cl. 315—291  [315/307; 315/247; 315/274; 315/224] 9 Claims
OG exemplary drawing
 
1. A method to control power supply to a cold-cathode fluorescent lamp (CCFL), comprising:
converting input power of said CCFL to said power supply applicable to said CCFL;
sensing electrical currents caused by said power supply in said CCFL so as to provide a corresponding feedback signal based on said sensed electrical current value;
providing two periodic wave signals having a non-zero amplitude of vibration respectively;
modifying one of said two periodic wave signals by means of said control signal;
outputting a waveform signal based on another comparative result of said two periodic wave signals including said modified one of said two periodic wave signals; and
controlling said power converting step according to said output waveform signal.