Pixel Driving Circuit for Uniform Light Emission in Displays
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Solution Overview
Problem
In display devices, the uneven distribution of driving current to light emitting elements leads to non-uniform light emission due to characteristic deviations among the elements, causing some elements to emit light while others do not.
Innovation Solution
A display device design that includes a first power line, a second power line, a data line, and a scan line, with each pixel connected to these lines and equipped with transistors and capacitors to independently drive light emitting elements, ensuring uniform current distribution and emission across all elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If light emitting elements are connected in parallel between power lines, then the structure is simple and easy to manufacture, but the driving current is unevenly distributed causing non-uniform light emission
Solution Approach 1:
The pixel circuit is divided into multiple independent driving transistor units, with each transistor dedicated to driving a specific light emitting element. This segmentation allows each element to receive independently controlled current, eliminating the uneven current distribution problem that occurs in parallel connections while maintaining manufacturing simplicity through modular circuit design.
Solution Approach 2:
Each light emitting element is equipped with its own dedicated driving transistor and storage capacitor, creating locally optimized current control circuits. This local quality approach ensures that each element receives precisely controlled current according to its specific characteristics, achieving uniform light emission across all elements while keeping the overall structure manageable.
2Manufacturing precision
If a dedicated driving transistor is provided for each light emitting element, then uniform light emission is achieved, but the device complexity increases
Solution Approach 1:
The pixel circuit is divided into multiple independent driving transistor units, with each transistor dedicated to driving a specific light emitting element. This segmentation allows each element to receive independently controlled current, eliminating the uneven current distribution problem that occurs in parallel connections while maintaining manufacturing simplicity through modular circuit design.
Solution Approach 2:
Multiple functional components (driving transistor, storage capacitor, and light emitting element) are merged into integrated pixel units. This merging approach consolidates the control functions within each pixel, managing device complexity through functional integration while maintaining precise current control for uniform light emission.
3Reliability
If storage capacitors are added to maintain driving voltage, then current stability is improved, but the device complexity and area increase
Solution Approach 1:
Multiple functional components (driving transistor, storage capacitor, and light emitting element) are merged into integrated pixel units. This merging approach consolidates the control functions within each pixel, managing device complexity through functional integration while maintaining precise current control for uniform light emission.
Solution Approach 2:
The storage capacitors serve multiple functions: maintaining driving voltage during the display period, stabilizing current flow to light emitting elements, and working in conjunction with driving transistors to enable precise grayscale control. This multi-functionality justifies the added components by providing several critical functions within the pixel circuit.
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 design allows for uniform light emission from all light emitting elements in each pixel, improving the display's performance and image quality by ensuring consistent illumination.
Implementation Method 1
each of the plurality of pixels may include light emitting elements electrically connected between the first power line and the second power line
Implementation Method 2
a technique of configuring a light source of a light emitting device using subminiature light emitting elements
Data Source
AI summary
A display device may include a first power line; a second power line; a data line that transmits a data signal; a scan line that transmits a scan signal; and pixels electrically connected to the first power line, the second power line, the data line, and the scan line. Each of the pixels may include light emitting elements electrically connected between the first power line and the second power line; and a first transistor that provides driving current to the light emitting elements in response to the data signal.