Display Device Test Pixel Areas for Substrate Inspection
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Solution Overview
Problem
There is a need for a display device that can easily monitor efficiency decreases after the first and second display substrates are attached, as existing technologies face challenges in inspecting the characteristics of light transmission patterns, wavelength conversion patterns, color filters, and light emitting elements when they overlap, making it difficult to determine which components affect the efficiency or deteriorate the display device's performance.
Innovation Solution
The display device includes a first substrate with a display area and a non-display area containing test pixel areas, where test light emitting elements, wavelength conversion patterns, and color filters are strategically positioned to allow for the inspection of these components even when the substrates are attached, using a capping layer and light blocking layer to isolate and inspect the test areas effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If test pixel areas are provided in the non-display area with test light emitting elements, wavelength conversion patterns, and color filters, then inspection of component characteristics becomes possible after substrate attachment, but device complexity increases due to additional test structures and layers
Solution Approach 1:
The display device is segmented into display areas and non-display areas, with the non-display area further divided into test pixel areas. This segmentation allows test structures (test light emitting elements, wavelength conversion patterns, color filters) to be isolated in specific regions without interfering with the main display function, enabling independent inspection of component characteristics after substrate attachment.
Solution Approach 2:
The patent utilizes the spatial dimension by placing test structures in the non-display area rather than integrating them within the display pixel structure. This dimensional separation allows for comprehensive inspection of wavelength conversion patterns, color filters, and light emitting elements without adding complexity to the active display region.
2Measurement precision
If a capping layer is disposed between the wavelength conversion pattern and color filter in test areas, then inspection of wavelength conversion efficiency becomes possible, but manufacturing precision requirements increase due to additional layer positioning constraints
Solution Approach 1:
The capping layer is disposed in advance between the wavelength conversion pattern and color filter in test pixel areas during the manufacturing process. This preliminary action creates a structured inspection path that allows wavelength conversion efficiency to be measured by controlling light emission from test light emitting elements through the capping layer to the wavelength conversion pattern, with the color filter positioned above for reference comparison.
Solution Approach 2:
The capping layer acts as an intermediary element that facilitates the inspection of wavelength conversion efficiency. It is positioned between the wavelength conversion pattern and color filter to create a controlled optical path, allowing the test system to measure how effectively the wavelength conversion pattern converts light while using the capping layer as a reference structure.
3Productivity
If test structures are configured to inspect characteristics after substrate attachment, then quality control efficiency improves, but the difficulty of detecting and measuring specific component defects increases due to overlapping structures
Solution Approach 1:
The patent segments the inspection function into separate test pixel areas within the non-display area, where each test structure (test light emitting element, wavelength conversion pattern, color filter) is spatially separated and configured for specific inspection purposes. This segmentation enables systematic quality control of each component type while maintaining the ability to detect defects in overlapping structures through controlled light emission and observation paths.
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 enables easy monitoring of efficiency reductions in the display device by allowing for the inspection of light transmission and wavelength conversion efficiencies, as well as light emission characteristics, even when the substrates are combined, thereby facilitating the identification of performance-deteriorating components.
Implementation Method 1
Electrons and holes provided from the two electrodes may be recombined in the organic light emitting layer to generate excitons, and the generated excitons may be shifted from an excited state to a ground state to emit light
Implementation Method 2
a first wavelength conversion pattern disposed on the first color filter, the first wavelength conversion pattern overlapping the first color filter and the first light emitting element
Data Source
AI summary
A display device includes a first light emitting element on a first substrate and overlapping a first effective pixel area; test light emitting elements on the first substrate and overlapping the test pixel area; a first color filter on a second substrate and overlapping the first light emitting element; a first wavelength conversion pattern on the first color filter and overlapping the first color filter and the first light emitting element; a first test color filter on the second substrate and overlapping one of the test light emitting elements; and a first test wavelength conversion pattern on the second substrate and overlapping another one of the test light emitting elements. The first test wavelength conversion pattern and the first wavelength conversion pattern include a same first wavelength conversion material, and the first test color filter and the first color filter include a same first color colorant.