Offset Color Separation Element Arrays for Oblique-Angle Sensing

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Solution Overview

Problem

Color filters in color display devices and image sensors have low light use efficiency due to absorption of unwanted wavelengths, leading to significant light loss and image quality degradation at the edges where incident angles are oblique.

Innovation Solution

A color separation element array with offset first and second elements that adjust their positional relationship based on the incident angle to maintain efficient color separation across the entire image sensor, including the edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a color filter is used to separate colors in an RGB or CYGM color filter method, then color separation is achieved, but light use efficiency deteriorates because only 1/3 of incident light is transmitted while 2/3 is absorbed

Engineering Contradiction:
Improvelight use efficiencyVSAvoidcolor separation capability
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent extracts the color separation function from the color filter by introducing a color separation element that uses diffraction to separate colors. This element is positioned between the lens and the pixel array, allowing incident light to be separated into different colors before reaching the pixel array, thereby avoiding the light absorption problem of color filters while maintaining color separation capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The color separation element acts as an intermediary between the lens and the pixel array. It receives incident light from the lens and separates it into different colors through diffraction, then directs each color to the corresponding pixel. This intermediary approach solves the light efficiency problem by replacing the absorbing color filter with a diffracting element that redirects rather than absorbs light

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If a color separation element is used to improve light use efficiency, then light transmission is improved, but color separation efficiency deteriorates at edge portions where light is obliquely incident

Engineering Contradiction:
Improvelight use efficiencyVSAvoidcolor separation efficiency at edge
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent applies local quality by making the color separation element asymmetric in structure. Specifically, the height of the color separation element varies across different regions: it is taller at the center and shorter at the edges. This asymmetric design compensates for the oblique incidence of light at edge portions, maintaining effective color separation across the entire field of view while preserving the high light use efficiency benefit

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameters of the color separation element to optimize performance. By adjusting the height parameter of the color separation element across different spatial positions (center vs. edge), the design adapts to different light incident angles, ensuring consistent color separation efficiency throughout the image sensor while maintaining overall high light transmission

Inventive Principle:
Principle #35Parameter 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

Enhances light use efficiency and maintains uniform color characteristics across the entire image sensor by optimizing color separation even at oblique angles, reducing light loss and image distortion.

Implementation Method 1

The color separation element may separate colors of the incident light by using the diffraction or refraction characteristics of a light that varies according to a wavelength of the light

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

The color separation element may separate colors of the incident light by using the diffraction or refraction characteristics of a light that varies according to a wavelength of the light

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3805821B1Color separation element array, image sensor including the color separation element array, and image pickup apparatus including the color separation element array
Publication Date: 2025.07.30 SAMSUNG ELECTRONICS CO LTD
  • EP3805821B1 patent drawingFigure 1~2
  • EP3805821B1 patent drawingFigure 3~4
  • EP3805821B1 patent drawingFigure 5A~5B

AI summary

A color separation element array includes a plurality of color separation elements arranged in two dimensions and separating an incident light according to a wavelength such that, of the incident light, a light of a first wavelength is directed to a first direction and a light of a second wavelength that is different from the first wavelength is directed to a second direction that is different from the first direction, in which each of the plurality of color separation elements includes a first element and a second element that are sequentially arranged according to a traveling direction of the incident light, and the first element and the second element of at least one of the plurality of color separation elements are offset with respect to each other.