Under-Display Sensor Panel With Multi-Stack OLED for Uniform Luminance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing display panels with optical sensors face issues of increased bezel width and reduced image quality due to the placement of optical sensors, leading to differences in resolution and luminance between the light sensing area and the general area, resulting in a shorter lifespan of light-emissive elements in the light sensing area.
Innovation Solution
A display panel design with a light sensing area overlapping the optical sensor, featuring a multi-stack light-emissive element structure including a main and auxiliary light-emissive layer, which transmits light while maintaining higher luminance and equal lifespan to the general area's single-stack light-emissive elements, reducing the visibility difference and preventing dark spot defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the optical sensor is disposed under the display panel to transmit light through the pixel area, then the bezel width is reduced and the image display function is maintained across the entire display area, but the resolution in the light sensing area becomes lower than in the general area, causing visual differences between the two areas
Solution Approach 1:
The patent applies local quality by creating different pixel structures in different areas of the display panel. The light sensing area uses a mixed arrangement of transmissive pixel areas and reflective pixel areas, while the general area uses only reflective pixel areas. This local differentiation allows the light sensing area to transmit light to the optical sensor while maintaining adequate display resolution, and the reflective pixel areas to provide higher resolution in the general display area, thus resolving the contradiction between display area utilization and resolution uniformity.
2Illumination intensity
If the light-emissive element in the light sensing area operates at higher luminance to reduce the luminance difference between the light sensing area and the general area, then the luminance uniformity is improved, but the lifespan of the light-emissive element in the light sensing area is greatly reduced
Solution Approach 1:
The patent applies parameter changes by modifying the structural parameters of the light-emissive element in the light sensing area. Specifically, it introduces a multi-stack structure with multiple light-emissive layers (first light-emissive layer, second light-emissive layer, and third light-emissive layer) instead of a single light-emissive layer. This structural parameter change allows the element to achieve the required luminance for uniformity while distributing the operational stress across multiple layers, thereby extending the lifespan of the light-emissive element.
3Device complexity
If a single light-emissive layer is used in the light sensing area to simplify the structure, then the device complexity is reduced, but the luminance and lifespan performance is insufficient compared to the general area elements
Solution Approach 1:
The patent applies composite materials by constructing the light-emissive element in the light sensing area with multiple light-emissive layers (first light-emissive layer, second light-emissive layer, and third light-emissive layer) stacked together. Each layer can be made of different organic or inorganic light-emissive materials with complementary properties. This composite structure achieves superior luminance performance and extended lifespan while maintaining reasonable structural complexity, as the layers work synergistically to produce the desired optical and temporal characteristics.
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
The multi-stack structure in the light sensing area ensures higher luminance and extended lifespan, maintaining image quality and preventing dark spots, while the thickness adjustment layer ensures equivalent microcavity effects across the panel, reducing the difference in display qualities between the light sensing and general areas.
Implementation Method 1
a multi light-emissive element corresponding to the sub-pixel area of the light sensing area and including a main light-emissive layer and an auxiliary light-emissive layer disposed between first and second electrodes of the multi light-emissive element
Implementation Method 2
the thickness adjustment layer ensures equivalent microcavity effects across the panel, reducing the difference in display qualities between the light sensing and general areas
Data Source
AI summary
A display panel, a display device and a method for manufacturing a display panel are discussed. The display panel includes a display area, wherein a portion of the display area is a light sensing area that overlaps an optical sensor, and a remaining portion is a general area that does not overlap the optical sensor. The display area includes a plurality of sub-pixel areas disposed in the general area and the light sensing area, and a plurality of transmissive pixel areas disposed in a light sensing area, wherein the panel includes a general light-emissive element corresponding to the sub-pixel area of the general area and including a main light-emissive layer between first and second electrodes, and a multi light-emissive element corresponding to the sub-pixel area of the light sensing area and including a main light-emissive layer and an auxiliary light-emissive layer disposed between the first and second electrodes.