OLED Light Blocking Member Segmentation for Contrast
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Solution Overview
Problem
Organic light emitting devices (OLEDs) face a reduction in contrast ratio due to reflective metal electrodes acting as mirrors when exposed to external light, which affects their performance and viewing experience.
Innovation Solution
A display device design incorporating a light blocking member with separated portions and a light blocking filter covering specific regions to reduce parasitic capacitance and external light reflection, using polysilicon semiconductor layers and color filters to enhance contrast ratio, and a common reflective metal electrode for improved brightness control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a reflective metal electrode (Al or Ag) is used in OLED, then the device can be manufactured with simple structure and low cost, but the contrast ratio is reduced due to light reflection
Solution Approach 1:
The light blocking member is divided into multiple separated portions corresponding to different pixel regions (red, green, blue pixels). Each portion is positioned to block light reflection from specific electrode areas, allowing selective suppression of reflection while maintaining electrode functionality in emitting regions
Solution Approach 2:
A light blocking member comprising light blocking portions is introduced as an intermediary element between the reflective electrode and external light sources. This member selectively blocks reflected light from reaching the viewer while allowing emitted light from the OLED to pass through, thereby improving contrast ratio without removing the reflective electrode
2Manufacturing precision
If continuous light blocking member is used to block external light reflection, then contrast ratio is improved, but parasitic capacitance increases between adjacent pixels
Solution Approach 1:
The light blocking member is segmented into discrete portions with separation regions between them. These separation regions electrically isolate adjacent light blocking portions, preventing parasitic capacitance formation while each portion continues to block light reflection from its corresponding pixel region
Solution Approach 2:
The light blocking portions are strategically positioned to cover only the non-emitting regions where electrode reflection occurs, while leaving the emitting pixel regions uncovered. This localized approach blocks reflection where needed without interfering with light emission from active pixels
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 solution effectively reduces external light reflection and parasitic capacitance, enhancing the contrast ratio and viewing angle of OLEDs, while maintaining low power consumption and high response speed.
Implementation Method 1
a light blocking filter covering a portion of a separation region separating the light blocking portions
Implementation Method 2
a plurality of color filters disposed on the gate line, the data line, and the thin film transistor
Implementation Method 3
The injected electrons and holes are combined to form excitons, and the excitons emit light as discharge energy
Data Source
AI summary
A display device is provided. The display device includes a substrate, a light blocking member formed on the substrate as a plurality of light blocking portions separated from each other, a thin film transistor including a gate line, a data line, and a semiconductor layer formed on the light blocking member, a plurality of color filters formed on the gate line, the data line, and the thin film transistor, a pixel electrode formed on the color filters and connected to the thin film transistor, and a light blocking filter covering a portion of a separation region separating the light blocking portions.