OLED Pixel-Driving Circuit With Shared-Line Drift Compensation
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Solution Overview
Problem
OLED displays face issues of non-uniform light emission due to variations in driving transistor characteristics, necessitating compensation methods that require separate sense and data lines, which reduce pixel aperture rate and increase manufacturing costs.
Innovation Solution
A pixel-driving circuit with integrated sensing and driving sub-circuits that utilize a shared data line for sensing electrical parameters of both the driving transistor and OLED, eliminating the need for separate sense lines and enhancing pixel aperture rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate sense lines and data lines are laid in the display panel, then compensation for transistor drift can be achieved, but pixel aperture rate is reduced and manufacturing cost increases
Solution Approach 1:
The patent merges the sense line and data line into a single shared line structure. The same physical line is used for both sensing transistor characteristics and transmitting data signals, eliminating the need for separate sense lines and thereby increasing the pixel aperture rate while maintaining compensation functionality
Solution Approach 2:
The shared line serves multiple functions: it acts as a sense line for detecting transistor characteristics during the sensing period and as a data line for transmitting compensated data signals during the display period. This multi-functionality reduces the number of conductor lines required in the display panel
2Reliability
If separate sense lines and data lines are laid in the display panel, then compensation for transistor drift can be achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges the sense line and data line into a single shared line structure. The same physical line is used for both sensing transistor characteristics and transmitting data signals, eliminating the need for separate sense lines and thereby increasing the pixel aperture rate while maintaining compensation functionality
Solution Approach 2:
The shared line serves multiple functions: it acts as a sense line for detecting transistor characteristics during the sensing period and as a data line for transmitting compensated data signals during the display period. This multi-functionality reduces the number of conductor lines required in the display panel
3Area of stationary object
If a shared data line is used for sensing, then pixel aperture rate is enhanced, but circuit timing complexity increases
Solution Approach 1:
The patent employs periodic action by dividing the operation into distinct time periods: a sensing period where the shared line functions as a sense line for detecting transistor characteristics, and a display period where the same line functions as a data line for transmitting compensated signals. This time-division multiplexing resolves timing complexity through structured periodic operation
Solution Approach 2:
The patent makes the circuit configuration dynamic by using control signals to switch the function of the shared line between sensing and data transmission modes. The circuit adapts its configuration based on the operational phase, allowing the same physical structure to serve different purposes at different times
Data Source
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AI summary
A pixel-driving circuit in a display panel. The pixel-driving circuit includes a first transistor (T1) being provided with a fixed voltage, a driving transistor (DTFT) having a gate (B) configured to receive the fixed voltage controlled by the first transistor (T1) and a drain coupled to a first power supply (Vdd), a capacitor (C) coupled between the gate (B) and a source (A) of the driving transistor (DTFT), a light-emitting device (OLED) coupled to the source (A) and a second power supply (Vss), a second transistor (T2) having a drain coupled to the source (A) of the driving transistor (DTFT) and a source coupled to a data line, a sensing sub-circuit coupled to the data line in a first period, and a driving sub-circuit coupled to the data line in a second period. The sensing sub-circuit and the driving sub-circuit are configured to connect to the data line in a time-divisional manner respectively for sensing and compensating the pixel-driving circuit.