10-Transistor Pixel Circuit for PWM Threshold Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pixel circuits driven in pulse width modulation with internal threshold voltage compensation require 19 or more transistors and 3 or more capacitors, limiting their application to ultra-high resolution display apparatus due to integration challenges.
Innovation Solution
A pixel circuit design with fewer transistors, including 10 transistors and 2 capacitors, utilizing a pulse width modulation method for internal threshold voltage compensation, suitable for ultra-high resolution displays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional pixel circuits with 19 or more transistors and 3 or more capacitors are used for pulse width modulation with internal threshold voltage compensation, then threshold voltage compensation is achieved, but device area increases and integration becomes difficult
Solution Approach 1:
The patent merges the threshold voltage compensation function into the existing pixel circuit structure by utilizing the overlap period between gate signal transitions. The compensation transistor is integrated with the switching transistor, and the compensation capacitor shares the same node structure, thereby achieving threshold voltage compensation without adding separate dedicated compensation circuits.
Solution Approach 2:
The pixel circuit is designed to perform multiple functions using the same components: the switching transistor serves both as the pixel switching element and as part of the threshold voltage compensation mechanism. The overlap period of gate signals is utilized for both pixel activation and threshold compensation, making the circuit multi-functional and reducing overall component count.
2Reliability
If conventional pixel circuits with 19 or more transistors and 3 or more capacitors are used for pulse width modulation with internal threshold voltage compensation, then threshold voltage compensation is achieved, but integration density decreases
Solution Approach 1:
The patent combines multiple functions into shared circuit elements. The compensation transistor is merged with the switching transistor structure, and the compensation capacitor utilizes existing node connections rather than requiring dedicated capacitor structures. This merging approach significantly reduces the total component count and increases integration density.
Solution Approach 2:
The patent utilizes dynamic timing control through overlapping gate signal periods to achieve threshold voltage compensation. By dynamically controlling the timing of gate signals during the overlap period, the circuit performs compensation functions without requiring additional static circuit structures, thereby improving integration density.
3Productivity
If fewer transistors are used in the pixel circuit, then integration density improves, but circuit functionality may be compromised
Solution Approach 1:
The reduced transistor count is compensated by making each transistor multi-functional. The switching transistor performs both pixel switching and threshold voltage compensation roles. The gate signal overlap period is utilized for dual purposes: activating the pixel and performing threshold compensation, thereby maintaining full functionality with fewer components.
Solution Approach 2:
The pixel circuit performs threshold voltage compensation using its own internal components and existing signal timing, without requiring external compensation circuits or additional transistors. The circuit serves itself by utilizing the natural overlap period of gate signals and existing transistor structures to achieve compensation, maintaining functionality while reducing component count.
Data Source
AI summary
A pixel circuit includes a first transistor including a control electrode connected to a first node, a first electrode connected to a second node and a second electrode connected to a third node, a second transistor which applies a data voltage to the first transistor, a third transistor connected to the first node and the third node, a seventh transistor connected to a fourth node, where the seventh transistor applies a driving current to a light emitting element, a ninth transistor which applies a constant-current voltage to the fourth node and the light emitting element which emits a light based on the data voltage and the constant-current voltage. The first transistor is a P-type transistor, the second transistor is an N-type transistor, the third transistor is an N-type transistor, and the seventh transistor is a P-type transistor.