Four-Lens Optical System Compact Design Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image pickup optical systems face challenges in achieving a compact size with improved image forming performance, wide angle, and low cost, while effectively correcting chromatic aberration and maintaining image quality, especially in thin camera modules for mobile devices and personal computers.
Innovation Solution
An image pickup optical system comprising four lenses with specific refractive powers and shapes, including a biconvex, biconcave, meniscus, and biconcave lenses, along with a diaphragm positioned nearest to the object side, which satisfies specific conditional expressions to optimize focal length, curvature, and Abbe's number for improved performance and aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the number of lenses is reduced to two or three lenses with single focal length, then the overall length of the optical system is shortened, but the image forming performance and chromatic aberration correction deteriorate
Solution Approach 1:
The optical system is divided into four distinct lenses with different focal lengths and specific shapes (biconvex, biconcave, meniscus, and biconcave), allowing each lens to contribute to specific aberration corrections while maintaining a compact overall structure
Solution Approach 2:
Each lens is assigned specific local optical properties including different refractive powers, shapes, and positions to correct specific types of aberrations locally, with the fourth lens specifically designed to correct chromatic aberration and distortion at the image periphery
2Manufacturing precision
If four lenses are used to improve image forming performance and correct chromatic aberration, then the resolution for large number of pixels is improved, but the overall length of the optical system increases
Solution Approach 1:
The patent optimizes specific parameters including the focal length ratios (f1/f, f2/f, f3/f, f4/f), curvature radii ratios (r8-r9)/(r8+r9), and Abbe's number relationships to achieve compact dimensions while maintaining effective chromatic aberration correction through the fourth lens
3Adaptability or versatility
If the optical system is designed for wide angle and small size, then the adaptability for mobile devices is improved, but the peripheral light degradation and image quality worsen
Solution Approach 1:
The fourth lens is specifically designed with biconcave shape and negative refractive power to locally correct peripheral light degradation and distortion at the image periphery, while the overall four-lens configuration maintains wide angle capability
Solution Approach 2:
The patent optimizes the curvature radii ratio (r8-r9)/(r8+r9) and Abbe's number relationships to control peripheral light behavior and reduce degradation while maintaining wide angle performance
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 system achieves a compact overall length, effective aberration correction, and a wide angle of field, ensuring high image quality and reduced peripheral light degradation, suitable for use in portable devices like digital cameras and personal computers.
Implementation Method 1
a first lens having a biconvex shape, and a positive refractive power
Implementation Method 2
a second lens having a biconcave shape, and a negative refractive power
Implementation Method 3
a third lens having a meniscus shape with a concave surface thereof directed toward the object side, and a positive refractive power
Implementation Method 4
a fourth lens having a biconcave shape, and a negative refractive power
Data Source
AI summary
An image pickup optical system having four lenses includes in order from an object side, a first lens having a biconvex shape, and a positive refractive power, a second lens having a biconcave shape, and a negative refractive power, a third lens having a meniscus shape with a concave surface thereof directed toward the object side, and a positive refractive power, and a fourth lens having a biconcave shape, and a negative refractive power, and a diaphragm is disposed nearest to the object side, and the surface on the object side of the fourth lens does not have a point of inflection as well as the optical system satisfying the recited numerical conditions.