Increasing the number of colors output by a passive liquid crystal display
AssigneeATI Technologies, Inc.
InventorsCharles Leung, Keith Lee
Life of this patent
Estimating the term…
Abstract
A technique to increase the number of colors output by a passive color LCD display provides an increased number of grey levels for each pixel component. An M×N matrix pattern of pixel components is generated having a ratio of pixel components that are ON to the total number of pixel components to achieve a particular grey level on the passive color LCD screen, where M and N are greater or equal to two. The M×N matrix pattern is repeated for X frames, and at least one pixel component is ON in each frame. At the end of the Xth frame, the first matrix pattern for frame zero is repeated.
Claims10
A method for increasing the number of colors outputted by an LCD display, the method comprising the steps of:
- providing a plurality of groups of pixel matrix patterns, each group of pixel matrix patterns being associated with a corresponding grey level of a plurality of grey levels, each pixel matrix pattern including a respective number of row and a respective number of columns, at least one of the respective number of rows and the respective number of columns being identical for each pixel matrix pattern within a particular group of pixel matrix patterns, but being different between groups of pixel matrix patterns that are associated with consecutive grey levels of the plurality of grey levels;
- selecting one group of the plurality of groups of pixel matrix patterns to be displayed in at least a portion of the display based on a desired grey level of the plurality of grey levels to produce a selected group of pixel matrix patterns;
- and
- for each frame of a group of frames to be displayed on the LCD display, generating signals to produce a corresponding one of the pixel matrix patterns in the selected group of pixel matrix patterns, wherein each column and each row of the corresponding one of the pixel matrix patterns in the selected group of pixel matrix patterns includes an equal number of pixels that have at least one color component turned ON to achieve a particular output color over the frame.
A grey level generator circuit comprising:
- a plurality of pixel matrix pattern generators, each pixel matrix pattern generator of the plurality of pixel matrix pattern generators producing a respective group of pixel matrix patterns, each group of pixel matrix patterns being associated with a corresponding grey level of a plurality of grey levels, each pixel matrix pattern including a respective number of rows and a respective number of columns, at least one of the respective number of rows and the respective number of columns being identical for each pixel matrix pattern within particular group of pixel matrix patterns, but being different between groups of pixel matrix patterns that are associated with consecutive grey levels of the plurality of grey levels;
- a grey level determiner for determining a desired grey level from the plurality of grey levels;
- and
- a selector for selecting one group of the plurality of groups of pixel matrix patterns to be displayed in at least a portion of an LCD display based on the desired grey level to produce a selected group of pixel matrix patterns and
- for generating, for each frame of a group of frames to be displayed on the LCD display, signals to produce a corresponding one of the pixel matrix patterns in the selected group of pixel matrix patterns, wherein each column and each row of the corresponding one of the pixel matrix patterns in the selected group of pixel matrix patterns includes an equal number of pixels that have at least one color component turned ON.
Dependencies are inferred from the claim text.