Organic Light-Emitting Panel Bank Wall Inclination for Film Thickness Control
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Solution Overview
Problem
Existing organic light-emitting panel technologies face challenges in maintaining uniform film thickness across the entire panel due to difficulties in precisely forming minute convexities on bank surfaces, leading to uneven luminance.
Innovation Solution
The organic light-emitting panel incorporates a unique structure with specific inclination angles of bank walls to control the pinning location of ink, including a non-light-emitting cell between pixels, which helps in maintaining uniform film thickness by adjusting the inclination angles of bank walls to prevent uneven film thickness and electrical issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a convexity is provided on the surface of the bank to control the pinning location of ink, then uniform film thickness can be guaranteed to a certain degree, but it is difficult to form minute convexities to high precision across the entire panel
Solution Approach 1:
The invention changes the geometric parameters of the bank structure by providing an inclined surface with a specific inclination angle (α) ranging from 5 to 45 degrees. This parameter modification allows the ink to pin at a controlled location on the inclined surface, achieving uniform film thickness without requiring high-precision minute convexities. The inclination angle serves as a controllable parameter that directly influences ink pinning behavior.
Solution Approach 2:
The invention applies different inclination angles to different regions of the bank structure. Specifically, the bank has an inclined surface facing the light-emitting cell with a first inclination angle, while the opposite side has a second inclination angle that may differ. This local differentiation allows precise control of ink pinning location in the critical light-emitting region while maintaining manufacturing feasibility.
2Manufacturing precision
If the inclination angle of bank walls is adjusted to control ink pinning location, then uniform film thickness is achieved, but the device structure becomes more complex
Solution Approach 1:
The invention modifies the bank structure by introducing an inclined surface with a controllable inclination angle, transforming a traditionally vertical or flat bank surface into an angled structure. This single parameter change (inclination angle) provides effective control over ink pinning location and film thickness uniformity without requiring multiple additional components or complex mechanisms.
Solution Approach 2:
The bank structure employs asymmetric geometry with different inclination angles on opposite sides. The inclined surface facing the light-emitting cell has a first inclination angle optimized for ink pinning control, while the opposite side has a second inclination angle that may be different, creating an asymmetric structure that serves specific functional purposes while maintaining overall simplicity.
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 effectively prevents uneven film thickness and ensures excellent light-emitting characteristics by optimizing the pinning location of ink and vapor concentration distribution, resulting in uniform luminance across the panel.
Implementation Method 1
Each pixel of such a display device is composed of an anode and a cathode with an organic light-emitting layer therebetween. For driving the display device, holes are injected through the anode and electrons are injected through the cathode. Then, holes and electrons recombine in the organic light-emitting layer, and light is emitted.
Implementation Method 2
The organic light-emitting layer is formed by dripping ink that includes organic light-emitting material into each region partitioned by the banks and drying the ink.
Data Source
AI summary
A non-light-emitting cell 100c is provided between pixels 100a and 100b. Ink for forming an organic light-emitting layer is dripped substantially simultaneously into sub-pixels 100a1, 100a2, and 100a3 in the pixel 100a and a sub-pixel 100b1 in the pixel 100b. On the other hand, such ink is not dripped into the non-light-emitting cell 100c since the organic light-emitting layer is not formed in the non-light-emitting cell 100c. In a bank 105d, an inclination angle θd3 of a wall 105d3 facing the sub-pixel 100a3 is larger than an inclination angle θdc of a wall 105dc facing the non-light-emitting cell 100c. Similarly, in a bank 105e, an inclination angle θe1 of a wall 105e1 facing the sub-pixel 100b1 is larger than an inclination angle θec of a wall 105ec facing the non-light-emitting cell 100c.