Display Device Back Gate Line Voltage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display devices using p-channel transistors, the fluctuation of back gate voltage due to light emission affects the leakage of charge in the capacitance unit, leading to reduced display quality and non-uniformity of images.
Innovation Solution
A display device with a separate back gate line for the write transistor, independent of the power supply line, ensures a constant or stable voltage is supplied to the back gate, preventing voltage fluctuations from affecting the back gate voltage and reducing charge leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the power source voltage VCC is supplied as the back gate voltage over the power supply line PS1, then the number of interconnects is reduced, but the back gate voltage fluctuates in accordance with the emission of light by the display element
Solution Approach 1:
The patent segments the voltage supply system by introducing a separate back gate voltage supply line independent from the power supply line PS1. This allows the back gate voltage to be supplied through a dedicated path, preventing the voltage fluctuations caused by light emission current from affecting the back gate voltage, thus resolving the contradiction between reducing interconnect complexity and maintaining voltage stability.
2Loss of energy
If the back gate voltage fluctuates in accordance with the emission of light, then the charge leakage in the capacitance unit increases, but the display quality is reduced
Solution Approach 1:
The patent introduces an intermediary independent voltage supply line that mediates between the power source and the back gate of the write transistor. This intermediary path isolates the back gate voltage from the fluctuations caused by light emission current, preventing charge leakage in the capacitance unit and maintaining display quality without requiring changes to the existing power supply structure.
Data Source
AI summary
A display device includes a pixel array unit in which display elements constituting pixels are arranged in a two-dimensional matrix in a row direction and a column direction. Each of the display elements includes a current-driven light-emitting unit and a drive circuit for driving the light-emitting unit. The drive circuit includes at least a write transistor for writing a video signal and a drive transistor for applying current to the light-emitting unit. A voltage is supplied to a back gate of at least the write transistor via a back gate line provided separate from a power supply line that supplies a voltage to the drive transistor.