Column Data Driving Circuit Precharge Unit for Display Panels
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Solution Overview
Problem
Conventional liquid crystal display devices face challenges in reducing signal delay and power consumption due to the need for multiple buffers in column data drivers, which increases chip size and power usage, especially in typical TFT panels.
Innovation Solution
A column data driving circuit that includes a precharge unit to precharge column lines using preset signals and a driving unit to sequentially drive the lines with data signals, reducing the number of buffers required and improving settling time margins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple buffers are used in column data drivers to drive column lines, then signal quality and image display are improved, but chip size and power consumption increase
Solution Approach 1:
The patent applies preliminary action by precharging column lines before actual data signal driving. The precharge unit charges column lines to predetermined voltage levels in advance, so when data signals arrive, the lines are already prepared for rapid switching. This eliminates the need for multiple buffers during data driving, reducing power consumption while maintaining signal quality.
Solution Approach 2:
The patent segments the column data driver functionality into two distinct units: a precharge unit that handles voltage level preparation, and a driving unit that handles data signal transmission. This segmentation allows each unit to be optimized for its specific function, with the precharge unit using fewer resources and the driving unit focusing on signal integrity.
2Speed
If multiple buffers are used in column data drivers, then signal delay is reduced, but chip size increases
Solution Approach 1:
By precharging column lines to predetermined voltage levels before data signals are applied, the patent eliminates signal delay without requiring multiple buffers. The precharge unit prepares the electrical state of column lines in advance, enabling rapid response when data signals arrive, thus reducing signal delay while minimizing chip area.
Solution Approach 2:
The patent introduces dynamic control of column lines through selective precharging. Different column lines can be precharged to different voltage levels based on the required data signals, optimizing signal transition speed for each line individually without requiring permanent multiple buffer structures.
3Use of energy by stationary object
If the number of buffers is reduced using time-sharing method, then chip size and power consumption are reduced, but settling time margin deteriorates
Solution Approach 1:
The patent resolves the settling time issue by performing preliminary precharging of column lines before data signals are applied. This advance preparation ensures that column lines reach their target voltage levels quickly, providing sufficient settling time margin even with reduced buffers. The precharge unit operates in advance, decoupling the buffer reduction from settling time degradation.
4Reliability
If multiple buffers are used to drive column lines simultaneously, then image quality is maintained, but power consumption increases
Solution Approach 1:
The patent maintains image quality by precharging column lines to the correct voltage levels before data signals are applied. This preliminary action ensures that when data signals drive the column lines, the transitions are clean and accurate, preserving image quality without requiring multiple buffers operating simultaneously, thus reducing power consumption.
Solution Approach 2:
The patent employs periodic precharging cycles where column lines are charged to predetermined voltage levels in sequence before data signal application. This periodic preparation ensures each column line is ready for its specific data signal, maintaining image quality through controlled, timed voltage transitions rather than continuous multiple buffer operation.
Data Source
AI summary
Provided are a column data driver configured to apply a voltage or current corresponding to image data to a display panel, a display device having the column data driver, and a driving method of the display device. The column data driving circuit includes a precharge unit configured to precharge at least one of a plurality of column lines in response to a plurality of preset signals corresponding to image data; and a driving unit configured to sequentially drive the plurality of column lines in response to a data signal corresponding to the image data.