Reflective Display Panel Color Filter for Yellow Tint Correction

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Solution Overview

Problem

Reflective display panels with a film thickness between 1200Å and 1700Å exhibit a yellowish background color due to the interaction of the transparent electrode layer, affecting display quality.

Innovation Solution

A reflective display panel design with a color filter layer comprising three filter patterns, each with specific absorbance ranges in different wavelength bands, to control and minimize yellowish background color by optimizing light transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transparent electrode layer film thickness is controlled between 1200Å and 1700Å to achieve high conductivity, then the electrical conductivity is improved, but the background color becomes yellowish which deteriorates display quality

Engineering Contradiction:
Improveelectrical conductivityVSAvoidyellowish background color
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A color filter layer is introduced as an intermediary component between the transparent electrode layer and the liquid crystal layer. This color filter layer specifically absorbs yellow light wavelengths while allowing other visible light to pass through, thereby compensating for the yellowish tint caused by the transparent electrode layer and restoring a neutral white background color without affecting the electrical conductivity of the electrode layer

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies color filtering technology by designing a color filter layer with specific absorbance characteristics. The filter layer is engineered to selectively absorb yellow light (wavelengths around 560-580nm) while transmitting other wavelengths, thereby changing the overall color perception of the background from yellowish to white, without modifying the transparent electrode layer itself

Inventive Principle:
Principle #32Color changes

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 design significantly improves the background color to a closer white appearance by managing light absorbance across various wavelengths, enhancing display quality.

Implementation Method 1

Absorbance of the first filter pattern in a wavelength range between 630 nm and 780 nm is less than 0.05, and absorbance in a wavelength range between 530 nm and 580 nm is greater than or equal to 0.25 and less than or equal to 0.9

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP4675345A1Reflective display panel
Publication Date: 2026.01.07 HANNSTAR DISPLAY CORP
  • EP4675345A1 patent drawingFigure 1
  • EP4675345A1 patent drawingFigure 2
  • EP4675345A1 patent drawingFigure 3

AI summary

A reflective display panel (10) including a first substrate (SUB1), a second substrate (SUB2), a liquid crystal layer (LCL), a pixel driving layer (PDL), a color filter layer (CFL), and a polarizer (POL). The pixel driving layer (PDL) is provided with a reflective layer (RFL) overlapping the color filter layer (CFL). Absorbance of a first filter pattern (FP1) of the color filter layer (CFL) is greater than or equal to 0.25 and less than or equal to 0.9 in a wavelength range between 530 nm and 580 nm. Absorbance of a second filter pattern (FP2) is greater than or equal to 0.8 and less than or equal to 1.25 in a wavelength range between 630 nm and 680 nm. Absorbance of a third filter pattern (FP3) is greater than or equal to 0.95 and less than or equal to 1.3 in a wavelength range between 580 nm and 630 nm.