Stacked Light Detector Filtering Visible Light in Peripheral Regions

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Solution Overview

Problem

Current solid-state imaging apparatuses face challenges in effectively distinguishing between visible light and infrared light, leading to unwanted light interference and reduced image quality due to the lack of efficient wavelength filtering in peripheral regions.

Innovation Solution

A light detection apparatus with a stacked structure including a first photoelectric conversion unit for visible light, a second photoelectric conversion unit for infrared light, and optical filters that allow easier transmission of infrared light, while preventing visible light from entering the peripheral regions, thereby reducing unwanted light interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If only a first optical filter is provided between photoelectric conversion units in the effective region, then the device complexity is reduced, but unwanted light from the peripheral region enters the second photoelectric conversion unit causing interference

Engineering Contradiction:

Improveoptical filter configurationVSAvoidunwanted light interference

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing a second optical filter specifically in the peripheral region adjacent to the effective region, while the effective region only has the first optical filter. This localized addition of the second optical filter blocks unwanted light from the peripheral region before it reaches the second photoelectric conversion unit, thereby reducing interference without unnecessarily increasing device complexity across the entire device.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the second photoelectric conversion unit detects light in a second wavelength range, then the functionality and versatility of the imaging apparatus is improved, but unwanted light in the first wavelength range causes interference

Engineering Contradiction:

Improvemulti-wavelength detection capabilityVSAvoidcross-wavelength light interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses the second optical filter as an intermediary element in the peripheral region that selectively blocks unwanted light in the first wavelength range before it reaches the second photoelectric conversion unit. This intermediary filter allows the second photoelectric conversion unit to maintain its ability to detect light in the second wavelength range while preventing cross-wavelength interference from the peripheral region.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances the signal-to-noise ratio, resolution, and ranging accuracy by preventing unwanted light from entering the photoelectric conversion units, resulting in improved imaging performance and high integration of visible and infrared light images.

Implementation Method 1

an effective region provided with a photoelectric converter that detects irradiation light and performs photoelectric conversion

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 2

The optical filter is provided between the first photoelectric conversion unit and the second photoelectric conversion unit and through which the light in the second wavelength range transmits more easily than the light in the first wavelength range

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentUS20240031703A1Light detection apparatus, light detection system, electronic equipment, and mobile body

Publication Date: 2024.01.25 SONY SEMICON SOLUTIONS CORP

AI summary

Provided is a light detection apparatus with high functionality. The light detection apparatus includes an effective region provided with a photoelectric converter that detects irradiation light and performs photoelectric conversion, and a peripheral region provided adjacent to the effective region. The photoelectric converter has a stacked structure including a first photoelectric conversion unit, a second photoelectric conversion unit, and a first optical filter. The first photoelectric conversion unit detects light in a first wavelength range of the irradiation light and performs photoelectric conversion. The second photoelectric conversion unit is provided so as to overlap with the first photoelectric conversion unit, detects light in a second wavelength range of the irradiation light, and performs photoelectric conversion. The first optical filter is provided between the first photoelectric conversion unit and the second photoelectric conversion unit and through which the light in the second wavelength range transmits more easily than the light in the first wavelength range. The peripheral region is provided with a second optical filter through which the light in the second wavelength range transmits more easily than the light in the first wavelength range.