OLED Display Crank-Shaped Touch Lines for Illuminance Sensing
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Solution Overview
Problem
Display devices with organic light emitting diodes (OLEDs) face challenges in maintaining display quality and ensuring sufficient light transmission for illuminance measurement due to the presence of electrodes and metal lines, which can obstruct light paths and lead to misalignment issues.
Innovation Solution
The design incorporates a crank-like shape for the metal lines of the touch panel electrodes, ensuring they do not overlap the light-emitting regions, and provides transmissive areas for illuminance measurement, even with potential misalignments during manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If metal lines are provided in the display area to realize touch panel function, then touch detection capability is improved, but display quality is reduced due to obstruction of light paths
Solution Approach 1:
The metal line is configured to extend in the second direction (vertical direction in the display area) rather than horizontally, utilizing the vertical dimension to minimize interference with horizontal light paths. This dimensional reorientation allows the touch electrode to maintain its functionality while reducing obstruction of light transmission to the OLED display elements.
Solution Approach 2:
The display area is divided into multiple pixel regions with the metal line positioned between them, segmenting the touch electrode structure to follow the pixel boundaries. This segmentation allows the metal line to be distributed across multiple locations rather than forming a continuous horizontal obstruction, thereby maintaining touch functionality while minimizing impact on display quality.
2Adaptability or versatility
If transmissive region is provided for illuminance measurement, then illuminance sensing capability is improved, but manufacturing alignment precision requirements increase due to potential misalignment
Solution Approach 1:
The transmissive region is pre-configured in a fixed position relative to the pixel aperture during the display element fabrication process, before final assembly. This preliminary positioning ensures that the transmissive region is already aligned with the pixel structure, reducing the need for high-precision alignment during subsequent manufacturing steps and accommodating potential variations in assembly tolerances.
Solution Approach 2:
The transmissive region serves multiple functions: it allows light transmission for OLED operation, enables illuminance measurement by the photoelectric conversion element, and provides a reference structure for alignment. This multi-functionality reduces the need for separate dedicated alignment features, thereby relaxing manufacturing precision requirements while maintaining sensing capability.
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 maintains display quality by preventing reductions in the light-emitting area while ensuring sufficient light transmission for illuminance measurement, enhancing the functionality of the display device.
Implementation Method 1
an organic layer which is provided between the lower electrode and the upper electrode and emits light based on a potential difference between the lower electrode and the upper electrode
Implementation Method 2
an illumination sensor which is provided on a back side of the substrate and measures an illuminance of light which enters the display device through a front side of the substrate
Data Source
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AI summary
According to one embodiment, a display device includes a substrate, a plurality of pixels each of which includes a display element consisting of a lower electrode, an upper electrode and an organic layer, a partition, a touch panel electrode which detects an object which contacts or approaches a display area, and an illumination sensor which is provided on a back side of the substrate and measures an illuminance of light which enters the display device through a front side of the substrate. Each of the pixels includes a transmissive region in which the display element is not provided. The touch panel electrode includes a metal line located above the partition, extending along the partition and having a crank-like shape near a transmissive region included in each of the pixels.