Electro-Optical Device Dual-End Drive Circuit Timing
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Solution Overview
Problem
Existing organic EL display devices face challenges in precisely managing the timing of mobility compensation operations due to parasitic capacitance and resistance in drive circuits, leading to variations in light-emission luminance across multiple transistors, which complicates image quality improvement.
Innovation Solution
The implementation of a scanning line drive circuit that supplies control signals to both ends of the light emitting control line, ensuring precise timing for the light emitting control transistor's conductive state, and the use of separate drive circuits for writing and light emitting control signals to maintain the switching element in a conductive state, thereby simplifying mobility compensation and reducing signal distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single drive circuit supplies control signals to multiple unit circuits, then device complexity is reduced, but signal distortion occurs due to parasitic capacitance and resistance, causing timing variations in mobility compensation operations
Solution Approach 1:
The scanning line drive circuit is divided into multiple independent drive circuits, each responsible for supplying control signals to a specific group of unit circuits. This segmentation eliminates the parasitic capacitance and resistance issues that occur in long signal lines, ensuring precise timing for mobility compensation operations while maintaining manageable device complexity through modular architecture.
Solution Approach 2:
The patent introduces separate drive circuits as intermediary components between the control system and unit circuits. These intermediary drive circuits receive control signals and distribute them to multiple unit circuits with minimized signal degradation, acting as buffer zones that prevent timing variations caused by direct long-distance signal transmission.
2Reliability
If the light emitting control transistor is turned on for mobility compensation, then mobility variation is compensated, but the timing must be precisely managed to avoid excessive or insufficient current damping
Solution Approach 1:
The drive circuit incorporates feedback mechanisms that monitor the state of unit circuits and automatically adjust the timing of mobility compensation operations. By detecting whether unit circuits are in writing or light emitting mode, the feedback system ensures the light emitting control transistor is turned on at the correct time, eliminating the need for complex manual timing management while maintaining high reliability.
Solution Approach 2:
The system performs mobility compensation automatically based on the operational state of unit circuits. The drive circuit self-regulates the timing of mobility compensation operations by monitoring its own output signals and the responsive states of unit circuits, turning on the light emitting control transistor precisely when needed without external intervention, thus simplifying operation while ensuring reliability.
3Adaptability or versatility
If multiple drive transistors are used in parallel, then light-emission luminance can be adjusted for each element, but variations in transistor characteristics cause luminance inconsistency across the display
Solution Approach 1:
The patent applies local quality by providing each unit circuit with its own light emitting control transistor that can be independently controlled. This allows mobility compensation to be performed locally for each transistor based on its specific characteristics, ensuring that luminance variations are compensated individually rather than applying a uniform control approach, thus achieving both adaptability and luminance uniformity.
Solution Approach 2:
The system dynamically changes the operational parameters of each drive transistor by selectively turning on the light emitting control transistor during mobility compensation. This parameter change approach allows each transistor's mobility to be adjusted individually through controlled current flow, compensating for manufacturing variations and achieving consistent luminance across all display elements.
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 configuration allows for precise management of mobility compensation operations across all unit circuits, reducing signal distortion and ensuring consistent light-emission luminance, thereby enhancing image display quality.
Implementation Method 1
a light emitting element 8 which emits light with an intensity in accordance with a magnitude of a drive current
Data Source
AI summary
An electro-optical device is provided that includes a plurality of unit circuits and a scanning line drive circuit. Each of the plurality of unit circuits includes a light emitting element, a drive transistor, a light emitting control transistor, and a switching element. Each of the plurality of scanning lines includes a light emitting control line. The scanning line drive circuit includes a first light emitting control line drive circuit connected to one end of the light emitting control line; and a second light emitting control line drive circuit connected to the other end of the light emitting control line. The first and second light emitting control line drive circuits supply the light emitting control signal to the light emitting control line from both ends thereof at a predetermined timing.