Display Device Parasitic Capacitance Frame Region Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing display devices with pulse width adjustment circuits on the panel face challenges in miniaturization due to increased circuit size, which hinders the reduction of the display panel's frame region and leads to higher costs and reduced yield.
Innovation Solution
Incorporating a common line wired along each pixel row with a switching transistor that connects to the drive transistor's source electrode, increasing the pixel capacitor's capacitance value through a parasitic capacitor, allowing for a shorter correction period without shortening the drive pulse width, thus eliminating the need for a pulse width adjustment circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a pulse width adjustment circuit is formed on the display panel to generate a shortened drive pulse, then the correction period can be shortened, but the circuit size of peripheral circuits increases and the frame region area increases
Solution Approach 1:
The patent extracts the pulse width adjustment function from the display panel's peripheral circuits by moving it to an external signal generation device. This allows the correction period to be shortened without increasing the frame region area, as the pulse width adjustment circuit is no longer formed on the display panel itself
Solution Approach 2:
The patent introduces an external signal generation device as an intermediary between the video signal source and the display panel. This intermediary device performs the pulse width adjustment function externally, enabling shortened drive pulses to be generated without requiring additional circuitry on the display panel
2Loss of time
If the pulse width of drive pulse is shortened to reduce correction period, then correction time is reduced, but circuit size of peripheral circuits increases
Solution Approach 1:
The patent extracts the pulse width adjustment functionality from the display panel's peripheral circuits and relocates it to an external signal generation device. This extraction reduces the circuit size of peripheral circuits on the display panel while still achieving the goal of shortening the correction time through externally generated shortened drive pulses
3Area of stationary object
If the frame region area is reduced for miniaturization, then display panel size is reduced, but it becomes difficult to accommodate pulse width adjustment circuits
Solution Approach 1:
The patent extracts the pulse width adjustment circuit from the display panel's frame region and relocates it to an external signal generation device. This allows the frame region area to be reduced for miniaturization purposes while the pulse width adjustment functionality is maintained externally, eliminating the need to accommodate such circuits within the reduced frame region
Solution Approach 2:
The external signal generation device serves multiple functions: it generates the video signal, adjusts the pulse width of drive pulses, and provides timing control. This multi-functionality allows the system to achieve miniaturization by eliminating on-panel pulse width adjustment circuits while maintaining all necessary signal processing capabilities externally
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 the circuit size of peripheral circuits, enabling a smaller display panel with improved yield and cost-effectiveness by shortening the mobility correction period without requiring a pulse width adjustment circuit, thereby enhancing image uniformity and miniaturization.
Implementation Method 1
a parasitic capacitor having a capacitance value larger than that of the pixel capacitor of each of pixel circuits is present in the common line wired along the pixel row
Data Source
AI summary
A display device includes a pixel array unit in which pixel circuits are disposed in a matrix form, the pixel circuits each including a light emission unit, a write transistor that writes a signal voltage of a video signal, a retention capacitor that retains the signal voltage written by the write transistor, and a drive transistor that drives the light emission unit on the basis of the signal voltage retained by the retention capacitor; and a common line that is wired along a pixel row, for each pixel row. The pixel circuit includes a switching transistor which selectively connects the common line and a source electrode of the drive transistor.