LCD Driving Circuit Black Matrix Segmentation for Parasitic Capacitance
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Solution Overview
Problem
The existing liquid crystal display (LCD) technologies suffer from parasitic capacitance between the black matrix and clock lines in the LOG area, leading to distortion of the clock signal and scanning pulse, resulting in prolonged rising and falling times.
Innovation Solution
The solution involves removing the black matrix from the LOG area where clock lines are present, and forming it only in the non-display area, thereby preventing parasitic capacitance and minimizing signal distortion. This is achieved by patterning a metal or black resin layer on a glass substrate and using LOG-type signal lines to supply necessary signals to the driving circuit without overlapping with the clock lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the black matrix is formed in the non-display area to block light, then light blocking performance is improved, but parasitic capacitance increases between the black matrix and clock lines
Solution Approach 1:
The black matrix formation is segmented into two distinct regions: the non-display area where the black matrix is formed to block light, and the LOG area where the black matrix is intentionally omitted to prevent parasitic capacitance. This spatial segmentation allows simultaneous achievement of light blocking performance and electrical signal integrity.
Solution Approach 2:
The black matrix is selectively applied only in specific regions (non-display area) while being absent in other regions (LOG area). This local quality approach ensures that the black matrix provides light blocking where needed without introducing parasitic capacitance in areas where clock lines are present.
2Reliability
If the black matrix is removed from the LOG area to reduce parasitic capacitance, then signal quality is improved, but light blocking coverage is reduced
Solution Approach 1:
The display panel area is segmented into display area, non-display area, and LOG area. The black matrix is selectively formed only in the non-display area, while being omitted from the LOG area. This segmentation ensures that light blocking coverage is maintained in the non-display area without compromising signal quality in the LOG area.
3Stability of the object's composition
If the black matrix is present in the non-display area, then structural integrity is improved, but signal distortion increases due to parasitic capacitance
Solution Approach 1:
The non-display area is further segmented into regions with and without the black matrix. The black matrix is formed in portions of the non-display area to maintain structural integrity, while being omitted in the LOG area to prevent signal distortion caused by parasitic capacitance between the black matrix and clock lines.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces parasitic capacitance and minimizes signal distortion, leading to faster rising and falling times of the scanning pulse, enhancing the overall performance of the LCD driving circuit.
Implementation Method 1
The liquid crystal cell Clc rotates liquid crystal molecules having a dielectric anisotropy by a potential difference between a data voltage supplied to the pixel electrode and a common voltage supplied to the common electrode to thereby control light transmittance
Implementation Method 2
parasitic capacitance between the black matrix and clock lines in the LOG area, leading to distortion of the clock signal and scanning pulse
Data Source
AI summary
A liquid crystal display panel having a built in driving circuit according to the present invention includes liquid crystal cells arranged in a matrix form in a display area of the panel and a driving circuit disposed outside the display area in a non-display area to drive the liquid crystal cells. The liquid crystal display panel also includes a plurality of LOG-type signal lines disposed at a LOG area within the non-display area to supply a plurality of signals to the driving circuit. In addition, the liquid crystal display panel includes a black matrix disposed in the non-display area excluding the LOG area so that the black matrix is absent in the LOG area.