Five-Lens Imaging System for Compact Smartphones
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Solution Overview
Problem
Existing imaging lenses for digital devices with high pixel counts and large image sensors face challenges in achieving a short total length, small F-number, and high imaging performance across central and peripheral angles of view, as they tend to become excessively long and have large F-numbers, making them unsuitable for modern smartphone and tablet applications.
Innovation Solution
A five-lens imaging lens configuration with specific refractive powers and shapes, including a first lens with positive refractive power and convex surface, a second lens with negative refractive power and concave surface, a third lens with positive refractive power and meniscus shape, a fourth lens with positive refractive power and concave surface, and a fifth lens with negative refractive power and aspherical concave surface, optimized to satisfy conditional formulae for focal lengths and angles of view, along with aspherical surfaces and an aperture stop placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a five lens configuration is used to increase pixel count and improve imaging performance, then imaging performance is improved, but total lens length becomes excessively long
Solution Approach 1:
The patent applies parameter changes by optimizing the refractive powers, focal lengths, and curvature radii of all five lens elements to satisfy specific conditional formulas. This allows the lens system to achieve high imaging performance for 8 megapixel or greater sensors while maintaining a compact total length suitable for modern smartphones and tablets.
Solution Approach 2:
The patent employs aspherical surfaces on specific lens elements (the second lens and the fifth lens) to correct optical aberrations more effectively than spherical surfaces alone. This enables improved imaging performance across the entire image area including peripheral regions, while allowing for a more compact lens design.
2Manufacturing precision
If lens configuration is optimized for high pixel count sensors, then imaging performance is improved, but F number becomes large
Solution Approach 1:
The patent optimizes multiple parameters including the F number by carefully selecting the refractive powers and focal lengths of each lens element. The conditional formulas ensure that the F number is kept small enough to provide sufficient light transmission for high pixel count sensors, while maintaining excellent imaging performance across central and peripheral angles of view.
3Length of moving object
If total lens length is shortened for compact devices, then device compactness is improved, but imaging performance at peripheral angles deteriorates
Solution Approach 1:
The patent uses aspherical surfaces on the second and fifth lens elements to effectively correct optical aberrations that typically worsen in compact lens designs. This allows the maintenance of high imaging performance across the entire image area including peripheral regions, even with a shortened total lens length suitable for modern thin smartphones and tablets.
Solution Approach 2:
The patent applies comprehensive parameter optimization by satisfying specific conditional formulas that coordinate the focal lengths, refractive powers, and curvature radii of all lens elements. This ensures that even with a compact total length, the lens system achieves excellent imaging performance from central to peripheral angles of view.
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 configuration achieves a shortened total lens length compatible with high pixel count image sensors, enables small F-numbers, and maintains high imaging performance from central to peripheral angles of view, enhancing the resolution and compactness of imaging devices.
Implementation Method 1
a fifth lens having a negative refractive power and a concave surface toward the image side, the surface thereof toward the image side being of an aspherical shape
Implementation Method 2
a first lens having a positive refractive power and a convex surface toward the object side
Implementation Method 3
a second lens having a negative refractive power and a concave surface toward the object side
Data Source
AI summary
An imaging lens is substantially constituted by five lenses, including: a positive first lens having a convex surface toward the object side; a negative second lens having a concave surface toward the object side; a positive third lens of a meniscus shape with a convex surface toward the object side; a positive fourth lens of a meniscus shape with a concave surface toward the object side; and a negative fifth lens having a concave surface toward the image side, the surface thereof toward the image side being of an aspherical shape having at least one inflection point within a range from an intersection of a principal light ray at a maximum angle of view with the surface toward the image side inwardly toward the optical axis in the radial direction, provided in this order from the object side. The imaging lens satisfies predetermined conditional formulae.