Six-Lens Optical System with Bonded Doublet for Brightness and Aberration Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical systems with six lenses struggle to achieve higher brightness while effectively correcting various types of aberrations.
Innovation Solution
The optical system comprises a first lens with negative refractive power, a stop, a second lens with positive refractive power, a third lens also with positive refractive power bonded as a doublet with the fourth lens having negative power, a fifth lens with positive power made of glass, and a sixth lens with positive power made of plastic having aspherical surfaces. This configuration ensures a telecentric portion on the demagnifying side and satisfies specific conditional expressions to optimize brightness and aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an optical system uses six lenses to achieve higher brightness, then brightness is improved, but aberration correction becomes difficult
Solution Approach 1:
The patent combines the third lens and fourth lens into a single doublet element, reducing the total number of separate lenses from six to five. This merging approach maintains the optical system's ability to achieve high brightness while simplifying the structure for better aberration correction. The doublet integrates the functions of two lenses into one element, optimizing the balance between brightness and optical quality.
Solution Approach 2:
The patent employs a composite lens structure where the doublet consists of a first lens made of plastic material and a second lens made of glass material. This composite material approach allows for optimized optical properties, enabling effective aberration correction while maintaining high brightness performance. The combination of plastic and glass materials provides complementary optical characteristics that enhance overall system performance.
2Manufacturing precision
If the optical system uses a telecentric portion on the demagnifying side, then image quality is improved, but system complexity increases
Solution Approach 1:
The sixth lens in the optical system serves multiple functions: it acts as a demagnifying lens, provides telecentricity on the demagnifying side for improved image quality, and contributes to aberration correction. By making this single element multi-functional, the patent achieves high image quality without proportionally increasing system complexity.
3Manufacturing precision
If the optical system uses plastic material with aspherical surfaces, then aberration correction is improved, but manufacturing difficulty increases
Solution Approach 1:
The patent uses a composite material structure where the first lens is made of plastic with aspherical surfaces for aberration correction, while the second lens is made of glass. This composite approach allows the plastic lens to provide sophisticated aberration correction through its aspherical shape, while the glass lens provides robustness and ease of manufacturing, thereby balancing performance and manufacturability.
Solution Approach 2:
The patent incorporates aspherical surfaces on the plastic lens to correct various types of aberrations. The aspherical curvature provides superior optical performance compared to spherical surfaces, enabling effective correction of aberrations while maintaining a manageable manufacturing process through established aspherical lens fabrication techniques.
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 system achieves a brightness of 1.6 or greater and effectively corrects various types of aberrations, including longitudinal aberration, astigmatism, and distortion, while maintaining a compact design.
Implementation Method 1
an optical system including a first lens having negative refractive power, a stop, a second lens having positive refractive power, a third lens having positive refractive power, a fourth lens having negative refractive power, a fifth lens having positive refractive power, and a sixth lens having positive refractive power
Data Source
AI summary
An optical system includes a first lens having negative refractive power, a stop, a second lens having positive refractive power, an aperture stop, a third lens having positive refractive power, a fourth lens having negative refractive power, a fifth lens having positive refractive power, and a sixth lens having positive refractive power, with the lenses sequentially arranged from the magnifying side toward the demagnifying side. The third and fourth lenses are bonded into a doublet, which has negative refractive power. One of the fifth and sixth lenses is made of plastic and has aspherical surfaces on opposite sides, and the other is made of glass. The portion on the demagnifying side of the sixth lens is a telecentric portion. Conditional Expression (1) below is satisfied,SD12/SD2<0.9 (1)where SD12 represents the effective radius of the stop, and SD2 represents the effective radius of the second lens.