Liquid Crystal Display Touch Panel Circuit Layout
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Solution Overview
Problem
In liquid crystal display devices with touch panels, the need for a shift register circuit to apply sequential voltage to drive electrodes results in uneven wiring lengths, necessitating thicker wiring and a larger frame region to achieve equivalent resistance, which increases the device's thickness and reduces display quality.
Innovation Solution
The configuration includes scanning signal lines, common electrodes, detection electrodes, display drive circuits, touch panel drive circuits, and switching circuits, where the touch panel drive circuit and display drive circuit are positioned outside the display region, with the touch panel drive circuit operating using two-phase clock signals and applying sequential drive pulses to common electrodes, and the display drive circuit applying scanning signals to either even- or odd-numbered scanning signal lines, reducing the frame region by minimizing wiring density and noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the shift register circuit is disposed in a driver IC and wiring is extended to the far portion of the display region, then the display region can be accessed, but the wiring length increases causing resistance imbalance and requiring thicker wiring which enlarges the frame region
Solution Approach 1:
The invention divides the drive circuits into separate functional blocks: a driver IC for control signals and a shift register circuit for sequential voltage generation. This segmentation allows the shift register to be positioned closer to the display region, reducing wiring length while maintaining electrical performance.
Solution Approach 2:
The shift register circuit is disposed in a direction different from the extending direction of the common electrodes, utilizing the frame region more efficiently. This dimensional repositioning reduces the wiring length to the far portion of the display region without requiring proportionally thicker wiring.
2Reliability
If the wiring width is increased to compensate for resistance in long wiring, then equivalent resistance is achieved, but the frame region must be enlarged to accommodate the thicker wiring
Solution Approach 1:
By segmenting the drive circuit functions and positioning the shift register circuit strategically, the invention reduces overall wiring length, thereby maintaining equivalent resistance with standard wiring dimensions and avoiding frame region enlargement.
Solution Approach 2:
The invention changes the spatial parameters of the circuit layout by disposing the shift register circuit in a direction different from the common electrode extension, optimizing the balance between wiring length, resistance, and frame region size.
3Reliability
If the frame region is enlarged to accommodate thicker wiring, then resistance balance is maintained, but the device thickness increases and display quality deteriorates
Solution Approach 1:
The shift register circuit is repositioned in a different spatial dimension relative to the common electrodes, which reduces wiring length and allows maintenance of resistance balance with standard wiring, thereby preserving display quality and device thickness.
Solution Approach 2:
By changing the layout parameters and circuit positioning, the invention achieves resistance balance without requiring enlarged frame region or thicker wiring, thus maintaining optimal display quality and device form factor.
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 configuration reduces the frame region size, enhances display quality by minimizing noise interference, and allows for thinner liquid crystal display devices while maintaining high durability and image quality.
Implementation Method 1
common electrodes that are a plurality of electrodes extended so as to horizontally cross the display region in the one direction, and that control an alignment of liquid crystal composition by forming an electric field in combination with pixel electrodes connected to the pixel transistors
Implementation Method 2
an electrostatic capacitance coupling type in which a change of capacitance is detected
Data Source
AI summary
A liquid crystal display device with a touch panel includes: display drive circuits that are disposed respectively at the outsides of the sides opposing to a display region, and that apply sequential scanning signal potentials to scanning signal lines; touch panel drive circuits that are disposed respectively further to the outsides of the display drive circuits, and that apply sequential drive pulses to a plurality or drive electrodes among common electrodes; and switching circuits that are disposed respectively at insides of the display drive circuits, and that switch between applying common electric potentials for controlling the alignment of the liquid crystal composition and applying a touch drive pulse that detects the touching to the display surface.