Optical Lens Assembly for Iris Recognition Using Infrared Filtering

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Solution Overview

Problem

Front-facing cameras in electronic devices face challenges in capturing clear iris images due to the wide viewing angle, which reduces iris pattern size and makes iris recognition more difficult, especially when natural light interferes with the image.

Innovation Solution

An optical lens assembly comprising a first lens with positive refractive power, a second lens with positive or negative refractive power, and a third lens with negative refractive power, sequentially arranged from the object side to the image side, incorporating a visible light cut-off filter to block visible light and enhance infrared light transmission, thereby improving iris image capture and recognition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a wide viewing angle is used to capture the entire user face, then the coverage area is improved, but the iris pattern size is reduced making recognition difficult

Engineering Contradiction:

Improvecoverage areaVSAvoidiris pattern size

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent changes the wavelength parameter of light from visible to infrared. By using infrared light instead of visible light, the system can capture iris patterns with sufficient size and clarity for recognition while maintaining the wide viewing angle needed to capture the entire user face. This parameter change resolves the contradiction between coverage area and measurement precision.

Inventive Principle:

Principle #35Parameter changes

2Illumination intensity

If natural light is allowed to enter the camera, then the brightness is improved, but the visible light interferes with infrared light transmission and degrades image quality

Engineering Contradiction:

ImprovebrightnessVSAvoidvisible light interference

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes visible light from the optical path using a visible light cut-off filter. This filter selectively blocks visible light wavelengths while allowing infrared light to pass through to the image sensor. By taking out the harmful visible light component, the system eliminates interference with infrared light transmission while maintaining the beneficial infrared illumination for iris capture.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The visible light cut-off filter acts as an intermediary element between the incoming light and the image sensor. This intermediary selectively transmits infrared light while blocking visible light, thereby mediating the interaction between light sources and the sensor to achieve clear infrared iris images without visible light interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Volume of moving object

If the camera system is miniaturized for mobile devices, then the device size is reduced, but the optical performance for iris recognition is degraded

Engineering Contradiction:

Improvecamera system sizeVSAvoidoptical performance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent changes the operating wavelength from visible to infrared, which enables effective iris recognition with a miniaturized optical system. Infrared light provides better penetration and contrast for iris patterns, allowing reliable recognition performance even in the compact form factor required for mobile devices. This parameter change resolves the contradiction between small size and optical 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 optical lens assembly effectively miniaturizes the camera system while ensuring high-quality iris image capture and accurate iris recognition by blocking visible light and utilizing infrared light, thus overcoming the limitations of wide viewing angles and natural light interference.

Implementation Method 1

an optical lens assembly includes a first lens L1 having a positive refractive power, a second lens L2 having a positive or negative refractive power, and a third lens L3 having a negative refractive power

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

incorporating a visible light cut-off filter to block visible light and enhance infrared light transmission

Methodology Applied

Scientific EffectOptical filtering: Filter (optical)

Data Source

PatentUS10520703B2Optical lens assembly and electronic device including the same

Publication Date: 2019.12.31 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided are an optical lens assembly and an electronic device. The optical lens assembly includes a first lens having a positive refractive power, a second lens having a positive or negative refractive power, and a third lens having a negative refractive power. The first lens, the second lens, and the third lens are sequentially arranged from an object side to an image side of an optical axis, the object side facing an object for image capture and the image side facing an image plane of an image sensor. The optical lens assembly and the electronic device may be configured to perform, for example, iris recognition for user authentication.