US Patent No. 10,893,591

CONTROLLERS, SYSTEMS, AND METHODS FOR DRIVING A LIGHT SOURCE


Patent No. 10,893,591
Issue Date January 12, 2021
Title Controllers, Systems, And Methods For Driving A Light Source
Inventorship Sheng-tai Lee, Taipei (TW)
Kaiping Ran, Fremont, CA (US)
Assignee O2Micro, Inc., Santa Clara, CA (US)

Claim of US Patent No. 10,893,591

1. A controller, operable for controlling a first output voltage that supplies electric power to a light source and also for controlling a second output voltage that supplies electric power to components except for said light source, wherein said first output voltage and said second output voltage are generated by a power converter, said controller comprising:a voltage detection terminal, operable for sensing said second output voltage;
a current detection terminal coupled to said light source, operable for sensing a current of said light source, wherein said second output voltage is sensed prior to said current of said light source; and
a voltage sensing terminal, coupled to said power converter through a voltage sensing circuit, operable for receiving a voltage sensing signal indicative of said first output voltage, wherein said voltage sensing signal is generated by said voltage sensing circuit; wherein said controller adjusts said voltage sensing signal based on said second output voltage, to generate an adjusted voltage sensing signal, and generates a first control current based on said adjusted voltage sensing signal, to enable said power converter to control said second output voltage in a preset voltage range based on said first control current;
wherein when said second output voltage is in said preset voltage range, said controller adjusts said adjusted voltage sensing signal based on a difference between said current of said light source and a target current value, to generate a twice-adjusted voltage sensing signal, and generates a second control current based on said twice-adjusted voltage sensing signal, to enable said power converter to control said current of said light source to maintain said target current value based on said second control current.