Absorptive Lens for Infrared Camera Visible Light Interference

Solution Overview

Problem

Camera modules using infrared light face challenges in obtaining clear images due to interference from visible light of different wavelengths, which is exacerbated by the need for reflective coatings that vary with incident angle, leading to reduced blocking efficiency and aesthetic issues with reflected light.

Innovation Solution

Incorporating a lens assembly with a first lens that absorbs visible light and one or more second lenses to refract light at a specified angle, combined with a filter that passes only the specified wavelength band of infrared light, ensuring clear image capture regardless of incident angle and improving device aesthetics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a reflective coating filter is used to block visible light, then the blocking rate for unwanted wavelengths is improved, but the blocking efficiency varies with incident angle causing image quality degradation

Engineering Contradiction:

Improveblocking rate for visible lightVSAvoidconsistent blocking efficiency

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the material parameter of the lens from conventional transparent materials to a material with visible light absorption properties. This fundamental parameter change allows the lens to inherently absorb visible light across different incident angles, eliminating the angle-dependent blocking efficiency problem of reflective coatings while maintaining high blocking performance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful effect of visible light into a beneficial filtering mechanism by using the lens material's natural absorption properties. Instead of relying on reflective coatings that create aesthetic issues and angle-dependent performance, the visible light is absorbed by the lens material itself, turning potential interference into an effective filtering mechanism that improves both image quality and device aesthetics.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If a reflective coating filter is used to block visible light, then the blocking rate for unwanted wavelengths is improved, but reflected light degrades device aesthetics

Engineering Contradiction:

Improveblocking rate for visible lightVSAvoiddevice aesthetics

Core Design Contradiction:

Object-affected harmful factorsVSShape

Solution Approach 1:

The patent converts the harmful effect of visible light into a beneficial filtering mechanism by using the lens material's natural absorption properties. Instead of relying on reflective coatings that create aesthetic issues and angle-dependent performance, the visible light is absorbed by the lens material itself, turning potential interference into an effective filtering mechanism that improves both image quality and device aesthetics.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the material parameter of the lens from conventional transparent materials to a material with visible light absorption properties. This fundamental parameter change allows the lens to inherently absorb visible light across different incident angles, eliminating the angle-dependent blocking efficiency problem of reflective coatings while maintaining high blocking performance.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If the bandwidth of the filter is set wider to accommodate angle variations, then adaptability to different incident angles is improved, but the blocking rate for unwanted wavelengths is reduced

Engineering Contradiction:

Improveadaptability to incident angleVSAvoidblocking rate for visible light

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter of the lens from conventional transparent materials to a material with visible light absorption properties. This fundamental parameter change allows the lens to inherently absorb visible light across different incident angles, eliminating the angle-dependent blocking efficiency problem of reflective coatings while maintaining high blocking performance.

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

The solution effectively filters out unwanted wavelengths, ensuring clear infrared images are obtained while minimizing external reflection, thus enhancing image quality and user experience.

Implementation Method 1

a first lens having a property to at least partially absorb visible light

Methodology Applied

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

Implementation Method 2

one or more second lenses to refract light output through the first lens at a specified angle

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 3

a filter to pass through light, which has the specified wavelength band, of the light output through the lens assembly

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentUS11368636B2Method for acquiring image corresponding to infrared rays by using camera module comprising lens capable of absorbing light in visible light band and electronic device implementing same

Publication Date: 2022.06.21 SAMSUNG ELECTRONICS CO LTD

AI summary

According to an embodiment of the disclosure, an electronic device includes a light source unit to emit infrared light having a specified wavelength band, a camera module, a memory, and a processor, the camera module includes a lens assembly including a first lens having a property to at least partially absorb visible light and one or more second lenses to refract light, which is output through the first lens, at a specified angle, a filter to pass through light, which has the specified wavelength band, of the light output through the lens assembly, and an image sensor to sense light, which is output through the lens assembly and the filter, to obtain an image, and the processor is configured to receive an input of a user to photograph an external object, emit the infrared light using the light source unit based on the input of the user, and obtain, using the camera module, an image corresponding to light, which is reflected from the external object, of the emitted infrared light.