Patents Assigned to CeeLight, Inc.
  • Constant brightness control for electro-luminescent lamp
    Patent number: 7719210
    Abstract: A ballast (11) includes a variable output DC converter source (12) and an inverter circuit (14) arranged to provide AC output voltage to an electro-luminescent (EL) lamp (16). A Q factor of EL lamp can characterize the age of the EL lamp. A series resonance-parallel loaded circuit and two voltage detector (18, 20) are constructed to measure the Q factor. A processor (17) controls the output of DC voltage source in accordance with a look-up table containing constant brightness algorithm based on the derived voltage and Q relationship.
    Type: Grant
    Filed: April 28, 2008
    Date of Patent: May 18, 2010
    Assignee: CeeLight, Inc.
    Inventor: Chih-Ping Liang