Sub-Wavelength Pixel Spectroscopy for Color Mixing Reduction

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Solution Overview

Problem

Existing imaging devices face inefficiencies in collecting incident light, leading to reduced sensitivity and potential color mixing due to the inability to effectively separate and direct different wavelength bands to their respective photoelectric conversion sections.

Innovation Solution

Incorporating a spectroscopic section with pillar-shaped structures having a size less than or equal to the wavelength of incident light, positioned between pixels, to separate and direct first and second wavelength lights to their corresponding photoelectric conversion sections, enhancing light collection efficiency and reducing unnecessary light leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a spectroscopic element with pillar-shaped structures is introduced to separate wavelength bands, then light separation precision is improved, but device complexity increases

Engineering Contradiction:

Improvewavelength separation precisionVSAvoidstructure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The spectroscopic element is divided into multiple pillar-shaped structures arranged in an array, where each pillar acts as an independent light separation unit. This segmentation allows efficient wavelength band separation while maintaining a relatively simple overall structure that can be integrated into the imaging device substrate.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional mechanical wavelength separation systems (such as prisms or diffraction gratings requiring complex optical paths) with a planar array of pillar-shaped structures that achieve wavelength separation through geometric configuration and light diffraction principles, simplifying the device architecture.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If the spectroscopic section is placed on the boundary between pixels, then light collection efficiency is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvelight collection efficiencyVSAvoidpositioning precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The pillar-shaped structures are positioned specifically at the boundaries between adjacent pixels, where they locally perform wavelength separation functions. This localized placement optimizes light collection for each pixel pair while maintaining overall system efficiency, and the boundary positioning naturally accommodates manufacturing tolerances.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If pillar-shaped structures with size less than or equal to wavelength are used, then light separation effectiveness is improved, but manufacturing difficulty increases

Engineering Contradiction:

Improvelight separation effectivenessVSAvoidmanufacturing ease

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent specifies that the pillar dimensions (width and height) be less than or equal to the wavelength of incident light, a critical parameter change that enables effective wavelength-based light separation. This dimensional constraint transforms the structures into sub-wavelength optical elements that can be manufactured using standard semiconductor fabrication techniques.

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

This configuration improves light collection efficiency and sensitivity by effectively separating and guiding different wavelength bands to their respective photoelectric conversion sections, minimizing color mixing and enhancing image quality.

Implementation Method 1

a spectroscopic section including a structure having a size less than or equal to a wavelength of incident light... separates the first wavelength light and the second wavelength light from the incident light

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 2

a first photoelectric conversion section that selectively receives first wavelength light included in a first wavelength band and performs photoelectric conversion of the first wavelength light

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS20240347557A1Imaging device

Publication Date: 2024.10.17 SONY SEMICON SOLUTIONS CORP

AI summary

An imaging device according to an embodiment of the present disclosure includes: a first pixel, a second pixel, and a spectroscopic section. The first pixel includes a first photoelectric conversion section that selectively receives first wavelength light included in a first wavelength band and performs photoelectric conversion of the first wavelength light. The second pixel includes a second photoelectric conversion section that selectively receives second wavelength light included in a second wavelength band and performs photoelectric conversion of the second wavelength band. The second pixel is adjacent to the first pixel. The spectroscopic section includes a structure having a size less than or equal to a wavelength of incident light, and is provided on a boundary between the first pixel and the second pixel. The spectroscopic section separates the first wavelength light and the second wavelength light from the incident light.