Driving circuit and method for increasing effective bits of source drivers
AssigneeHannstar Display Corp.
InventorsChin-Hung Hsu, Ming-Lin Lee, Chun-Chieh Chen, Nan-Ku Lu
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Abstract
An LCD driving circuit and method for increasing effective bit(s) of the source driver is disclosed. A reference voltage generator generates a group of compensated reference voltage levels that are interlaced with original reference voltage level of original reference voltage generator. One of the multiple groups of reference voltage levels is selected by one or more least significant bits (LSBs), and is then inputted to digital-to-Analog converter of the source driver under control of the one or more least significant bits (LSBs), thereby effectively and economically enhancing the gray levels of the display on the LCD panel.
Claims22
A reference voltage controlling method for increasing effective bit of an n-bit digital-to-analog converter (DAC) of a source driver, comprising:
- generating original multiple reference voltage levels and compensated multiple reference voltage levels;
- providing one or more least significant bit(s) (LSB) for selecting one of the original multiple reference voltage levels and compensated multiple reference voltage levels in sequence;
- inputting the selected one of multiple reference voltage levels at a time into the DAC of the source driver;
- and
- wherein the original multiple reference voltage levels are not overlapping compensated multiple reference voltage levels.
An LCD source driver, comprising:
- a data register sequentially sampling input digital video signals;
- a latch for latching the sampled digital video signals;
- a digital-to-analog converter for converting the digital video signals to analog video signals, the analog video signals then being outputted to an LCD panel;
- and
- a selector which selects one of multiple groups of reference voltages, and sequentially and alternatively provides the selected group of reference voltages to the digital-to-analog converter.
Dependencies are inferred from the claim text.