Protection for external electrode fluorescent lamp system
AssigneeO2Micro International Limited
InventorsYung-Lin Lin, Da Liu
Life of this patent
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Abstract
The present invention provides a driving circuit with protection function for driving a set of external electrode fluorescent lamps (EEFL) . The drive circuit includes, a transformer connected to the set of EEFLs, a switching network connected to the transformer which delivers power to the transformer, a sensing circuit connected to the set of EEFLs which detects disconnection if one light source is disconnected, and a controller connected to the switching network which controls the switching network to reduce the total current supplied to the EEFLs which remain connected, if the sensing circuit detects that one EEFL is disconnected. Appropriate protection can therefore be implemented when the EEFL is disconnected on one end or both ends.
Claims13
A liquid crystal display system comprising:
- a thin film transistor screen;
- a column driver coupled to said thin film transistor screen for controlling columns on said thin film transistor screen;
- a row driver coupled to said thin film transistor screen for controlling rows on said thin film transistor screen;
- a timing controller coupled to said column driver and said row driver for controlling timing for said column driver and said row driver;
- a video signal processor coupled to said timing controller for processing video signals;
- a plurality of cold cathode fluorescent lamps for illuminating said thin film transistor screen;
- a sensing circuit coupled to said plurality of cold cathode fluorescent lamps which detects disconnection if one cold cathode fluorescent lamp is disconnected;
- and
- a controller coupled to said plurality of cold cathode fluorescent lamps which reduces the total current supplied to the cold cathode fluorescent lamps which remain connected if said sensing circuit detects that said one cold cathode fluorescent lamp is disconnected.
Dependencies are inferred from the claim text.