Top Emission OLED Contrast via Direct Color Filter Patterning

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Solution Overview

Problem

Organic light emitting display apparatuses face challenges in improving contrast due to external light reflection, which is exacerbated by the complexity of forming a black matrix and color filter layers.

Innovation Solution

A top or bottom emission type organic light emitting display apparatus design that eliminates the need for a black matrix by directly patterning a color filter on a polarizing film, using a photolithography or laser-induced thermal imaging process, thereby simplifying the manufacturing process and reducing light reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a black matrix is formed on the non-pixel region to absorb light and reduce reflection, then contrast is improved, but the manufacturing process becomes complicated

Engineering Contradiction:

ImprovecontrastVSAvoidmanufacturing process complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the black matrix component entirely from the display structure. Instead of forming a black matrix on the non-pixel region, the patent uses a polarizing film in combination with a color filter that directly patterns the light transmission characteristics, removing the need for the black matrix layer and its associated manufacturing steps

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The color filter layer is designed to perform multiple functions: it generates the color image by filtering light wavelengths and simultaneously defines the pixel regions through direct patterning. This multi-functionality replaces the separate roles of the black matrix (defining pixel boundaries) and the color filter (generating colors), simplifying the overall structure

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Illumination intensity

If a color filter is formed to alternate with a black matrix on an encapsulation substrate to produce color images, then color display is achieved, but the manufacturing process becomes complicated

Engineering Contradiction:

Improvecolor image reproductionVSAvoidcolor filter and black matrix formation process

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The invention merges the color filter formation process with the pixel region definition process. The color filter is directly patterned on the polarizing film to form the pixel regions, combining what were previously separate functions (color filtering and pixel boundary definition) into a single integrated structure and manufacturing step

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Instead of forming the color filter on the encapsulation substrate as in conventional designs, the patent inverts the sequence by forming the color filter directly on the polarizing film. This reversal of the conventional layer formation sequence simplifies the manufacturing process by eliminating the need for subsequent black matrix formation

Inventive Principle:

Principle #13The other way round (Inversion)

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 design enhances contrast without the complexity of black matrix formation and simplifies the color filter manufacturing, effectively addressing the issues of external light reflection and manufacturing complexity.

Implementation Method 1

a polarizing film arranged on the encapsulating member

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 2

The color filter can include a red light transmitting region through which light in a red wavelength band passes, a blue light transmitting region through which light in a blue wavelength band passes and a green light transmitting region through which light in a green wavelength band passes

Methodology Applied

Scientific EffectOptical filtering by wavelength: Filter (optical)

Implementation Method 3

The color filter can be produced directly on the polarizing film by a photolithography process

Methodology Applied

Scientific EffectPhotolithography: Photography

Implementation Method 4

The color filter can be produced directly on the polarizing film by a laser induced thermal imaging (LITI) process

Methodology Applied

Scientific EffectLaser-induced thermal imaging: Laser

Data Source

PatentUS8174179B2Organic light emitting display apparatus

Publication Date: 2012.05.08 SAMSUNG DISPLAY CO LTD

AI summary

A top emission type organic light emitting display apparatus that can improve contrast without using a black matrix and can simply the manufacture of a color filter. The top emission type organic light emitting display apparatus includes a substrate, an organic light emitting device arranged on the substrate and including a first electrode layer and a second electrode layer arranged opposite to each other and an organic light emitting layer arranged between the first electrode layer and the second electrode layer, an encapsulating member arranged to encapsulate the organic light emitting device, a polarizing film arranged on the encapsulating member and a color filter arranged between the encapsulating member and the polarizing film, the color filter being arranged directly on the polarizing film.