Four-Lens Assembly With Abbe Control for Compact ToF Sensing
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Solution Overview
Problem
Existing optical devices in miniaturized electronic devices face challenges in accurately detecting distance information due to difficulties in miniaturizing structured light methods and environmental interference affecting Time-of-Flight (ToF) methods, leading to performance degradation.
Innovation Solution
A lens assembly comprising lenses with specific refractive powers and Abbe numbers, arranged along the optical axis, and a band-pass filter to enhance distance information detection, allowing for miniaturization and improved accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If structured light method is used for distance detection, then measurement precision is improved, but device complexity increases making miniaturization difficult
Solution Approach 1:
The patent extracts only the essential optical components needed for ToF measurement (lens assembly with specific Abbe number configuration and band-pass filter) while removing unnecessary complex structures, enabling miniaturization while maintaining measurement precision
Solution Approach 2:
The patent changes the optical parameters by specifying particular Abbe number ranges for each lens element and configuring their refractive powers, which optimizes the lens assembly for ToF measurement in a compact form factor
2Device complexity
If Time-of-Flight method is used for distance detection, then device complexity is reduced enabling miniaturization, but measurement precision degrades due to environmental interference
Solution Approach 1:
The band-pass filter acts as an intermediary element that transmits only the specific wavelength of modulated light used for ToF measurement while blocking environmental light interference, thereby improving measurement precision without increasing device complexity
Solution Approach 2:
The patent applies preliminary anti-action by using the band-pass filter to preemptively block harmful environmental light before it reaches the image sensor, preventing measurement errors before they occur
3Stability of the object's composition
If multiple lens elements with high Abbe numbers are used, then chromatic aberration is reduced, but manufacturing cost increases
Solution Approach 1:
The patent specifies particular Abbe number ranges for each lens element (first lens: 20-80, second lens: 20-80, third lens: 20-80, fourth lens: 20-80) that balance chromatic aberration correction with cost-effective material selection, avoiding unnecessarily high Abbe numbers that would increase manufacturing cost
Solution Approach 2:
The patent uses a composite lens assembly with four different lens elements having different Abbe numbers and refractive powers, where the combination of materials achieves effective chromatic aberration correction while maintaining reasonable manufacturing costs through optimized material selection
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 lens assembly provides compact, cost-effective, and accurate distance information detection suitable for miniaturized electronic devices, reducing chromatic aberration and simplifying materials, while maintaining high performance.
Implementation Method 1
a first lens having positive refractive power, a subject side surface of the first lens having a convex shape towards a subject; a second lens having positive refractive power, a subject side surface of the second lens including a center portion intersecting an optical axis having a convex shape towards the subject
Implementation Method 2
A lens assembly comprising lenses with specific refractive powers and Abbe numbers, arranged along the optical axis, and a band-pass filter to enhance distance information detection
Data Source
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AI summary
According to an embodiments, a lens assembly or an electronic device including the same may include: a first lens having positive refractive power; a second lens having positive refractive power; a third lens having positive or negative refractive power; and a fourth lens having positive or negative refractive power. The first lens, the second lens, the third lens, and the fourth lens may be sequentially arranged from a subject to an image sensor along an optical axis, and the sum of Abbe numbers of the first lens, the second lens, the third lens, and the fourth lens may satisfy Conditional Expression 1 as follows. 20 ≤ v1 + v2 + v3 + v4 < 125 where "v1," "v2," "v3," and "v4" represent the Abbe numbers of the first through fourth lenses, respectively.