Image Processing for Reflection-Type Displays with Segmented Sub-Pixel Layers

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Solution Overview

Problem

Existing reflection-type image display mediums struggle to accurately display white colors and maintain high image contrast, especially when using a juxtaposed-color structure with RGB sub-pixels, as they often require white balance adjustments and have limited design freedom for colors.

Innovation Solution

An image processing device and method that judges each pixel for chromatic or non-chromatic content, selects a black-and-white sub-pixel set based on gray levels for non-chromatic pixels, converts color data to black and colored sub-pixels for chromatic pixels, and replaces specific sub-pixel sets with a black-and-white set to enhance white reproduction and contrast.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a reflection-type juxtaposed-color structure with RGB sub-pixels is used, then color display capability is achieved, but white reproduction is limited to 33% reflectivity and white balance adjustment is required

Engineering Contradiction:

Improvewhite reflectivityVSAvoidwhite balance adjustment complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The invention divides the display system into two independent parts: a background layer with white and black particles for displaying white and black colors, and a foreground layer with colored particles for displaying chromatic colors. This segmentation allows white to be displayed using only the background layer, achieving 100% reflectivity without requiring white balance adjustment between RGB sub-pixels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The background layer is pre-configured with white and black particles that can independently display white and black without requiring subsequent adjustment. This preliminary setup eliminates the need for white balance adjustment, as the white display is achieved directly by the background layer before any chromatic color display is attempted.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If RGB sub-pixels are used for color display, then color gamut is covered, but design freedom for colors is reduced due to white balance requirements

Engineering Contradiction:

Improvecolor design freedomVSAvoidwhite balance precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

By segmenting the display into background layer (white/black particles) and foreground layer (colored particles), the invention decouples white display from color display. This allows independent optimization of white balance (handled by background layer) and color accuracy (handled by foreground layer), significantly increasing design freedom for colors without white balance constraints.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The background layer acts as an intermediary that handles the white display function, allowing the foreground layer to focus solely on chromatic color display. This intermediary structure eliminates the need for white balance adjustment between color sub-pixels, as the background layer provides the white reference independently.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Illumination intensity

If conventional electrophoretic display elements with dichroic colorants are used, then white and black display is achieved, but chromatic color display requires complex multi-colorant formulations

Engineering Contradiction:

Improvewhite and black display capabilityVSAvoidcolorant formulation complexity

Core Design Contradiction:

Illumination intensityVSDevice complexity

Solution Approach 1:

The invention separates the display functions into two layers: the background layer uses simple white and black particles for achromatic display, while the foreground layer uses colored particles for chromatic display. This segmentation eliminates the need for complex dichroic colorant formulations, as each layer uses simple, single-function particles.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of using complex dichroic colorants that attempt to achieve multiple functions in one material, the invention copies the successful simple particle approach from the background layer to the foreground layer, using colored particles that are structurally similar to the white and black particles but with different optical properties.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS7885457B2Image processing device and image processing method which are capable of displaying white, black and a color other than white and black at each pixel

Publication Date: 2011.02.08 E INK CORP

AI summary

An image processing device is provided for processing image data in order to display an image at an image display medium which is capable of displaying white, black, and colors at individual pixels, which are structured by pluralities of sub-pixels. The judgment component acquires the image data and judges whether there is a chromatic color or a non-chromatic color at each pixel. When a pixel is judged to be non-chromatic, the selection component selects a pre-specified black-and-white sub-pixel set in accordance with a gray level of the non-chromatic color. When a pixel is judged to be chromatic, the conversion component converts color data to a sub-pixel set of black and the color in accordance with a pre-specified condition. Of results of conversion, the replacement component replaces a pre-specified sub-pixel set of colors, in an individual pixel or in a pre-specified sub-pixel group, with a pre-specified black-and-white sub-pixel set.