Display Drive Circuit Layout for Stable Ramp Signal Line Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When a large number of signal lines are connected to ramp wiring connected to an output node of one amplifier, voltage fluctuations occur due to parasitic capacitance and wiring resistance, leading to inconsistent signal line voltages, especially in high-resolution and high-frame-rate displays.
Innovation Solution
A display drive circuit with a ramp wave voltage generation circuit and a signal line voltage generation circuit that includes an amplifier, load circuit, and current generation circuit to control current flow based on voltage comparisons, using switches and feedback paths to stabilize signal line voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a large number of signal lines are connected to ramp wiring from one amplifier, then the device complexity is reduced, but voltage fluctuation increases due to parasitic capacitance and wiring resistance
Solution Approach 1:
The patent divides the single amplifier into multiple amplifiers (first amplifier and second amplifier) to drive different groups of signal lines. This segmentation reduces the number of signal lines connected to each amplifier, thereby reducing parasitic capacitance and wiring resistance effects on each amplifier, while maintaining overall system functionality.
Solution Approach 2:
The patent applies different drive strategies to different signal line groups based on their specific requirements. The first amplifier drives odd-numbered signal lines with a first ramp wave voltage, while the second amplifier drives even-numbered signal lines with a second ramp wave voltage, allowing optimized local performance for each group.
2Productivity
If the frequency of ramp wave voltage is increased to support high frame rate, then the productivity is improved, but power consumption increases
Solution Approach 1:
By dividing signal lines into multiple groups driven by different amplifiers, the patent allows each amplifier to operate at a lower frequency while the overall system achieves high frame rate. This segmentation reduces the power consumption of individual amplifiers while maintaining high productivity.
3Area of stationary object
If the wiring length of ramp wiring is increased to cover large display area, then the area is improved, but voltage fluctuation increases due to wiring resistance
Solution Approach 1:
The patent divides the display area into multiple regions, each served by a separate amplifier. This segmentation reduces the wiring length from each amplifier to its connected signal lines, thereby reducing voltage fluctuation due to wiring resistance while covering a large overall display area.
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
The solution effectively curbs voltage fluctuations, improving display quality by maintaining consistent signal line voltages across the display area, even with varying capacitance and resistance conditions.
Implementation Method 1
an amplifier that outputs the ramp wave voltage
Implementation Method 2
the write voltage of the signal line may fluctuate due to parasitic capacitance between adjacent signal lines
Implementation Method 3
a current generation circuit that controls a current flowing through the load circuit according to the ramp wave voltage and a reference voltage
Implementation Method 4
a comparator that compares the ramp wave voltage with the reference voltage
Data Source
AI summary
Provided are a display drive circuit and a display device capable of curbing fluctuation of a signal line voltage. A display drive circuit includes a ramp wave voltage generation circuit that generates a ramp wave voltage whose voltage level changes with time, and a signal line voltage generation circuit that holds the voltage level of the ramp wave voltage at a timing corresponding to a signal level of a pixel signal and generates a signal line voltage. The ramp wave voltage generation circuit includes an amplifier that outputs the ramp wave voltage, a load circuit arranged on a feedback path of the amplifier, and a current generation circuit that controls a current flowing through the load circuit such that the ramp wave voltage matches a reference voltage.