OLED Scan Driver Merging for Bezel Reduction
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Solution Overview
Problem
Organic light-emitting display devices face challenges with increased manufacturing costs and bezel area due to the need for multiple scan drivers to drive switching and sensing transistors, which also lead to variations in sub-pixel characteristics affecting luminance.
Innovation Solution
The solution involves simultaneously driving first and second transistors in neighboring sub-pixels using a single scan driver, where the gate node of one sub-pixel is connected to the gate node of an adjacent sub-pixel, allowing shared scan signals to reduce the size of the scan driver and bezel area, while internal compensation for characteristic variations is achieved using a single scan driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple scan drivers are used to drive switching and sensing transistors in each sub pixel, then the sub pixel characteristics can be controlled, but the manufacturing cost increases and the bezel area increases
Solution Approach 1:
The patent merges the functions of multiple scan drivers into a single scan driver by connecting gate nodes of transistors in neighboring sub pixels. Specifically, the gate node of the switching transistor in one sub pixel is connected to the gate node of the sensing transistor in an adjacent sub pixel, allowing one scan driver to simultaneously control both transistors through shared gate signals, thereby reducing the number of scan drivers and associated costs
2Reliability
If multiple scan drivers are used to drive switching and sensing transistors in each sub pixel, then the sub pixel characteristics can be controlled, but the bezel area increases
Solution Approach 1:
The patent reduces bezel area by merging scan driver functions through shared gate node connections. By connecting the gate node of the switching transistor in one sub pixel to the gate node of the sensing transistor in a neighboring sub pixel, the system eliminates the need for separate scan drivers, thereby reducing the physical space required for driver circuits in the bezel region
3Area of stationary object
If one scan driver is used to simultaneously drive transistors in neighboring sub pixels, then the scan driver size and bezel area decrease, but the driving complexity increases
Solution Approach 1:
The scan driver is designed with multi-functionality to handle both switching transistor driving and sensing transistor driving through shared gate node connections. The same scan driver output signal serves dual purposes: controlling the switching transistor in one sub pixel and the sensing transistor in an adjacent sub pixel, thereby reducing driver size while managing complexity through universal signal usage
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 decreases the size of the scan driver and bezel area, enabling efficient internal compensation for sub-pixel characteristic variations, thereby reducing manufacturing costs and improving display performance.
Implementation Method 1
employ organic light-emitting diodes (OLED) that emit light by themselves
Data Source
AI summary
An organic light-emitting display device includes a display panel, a source driver, a scan driver, and a timing controller. A gate node of a second transistor of an (N−1)-th sub pixel and a gate node of a first transistor of an N-th sub pixel are connected in common such that the second transistor of the (N−1)-th sub pixel and the first transistor of the N-th sub pixel are simultaneously turned on by a scan signal supplied to the second transistor of the (N−1)-th sub pixel. Accordingly, it is possible to decrease a size of the scan driver and a bezel area.