Dry Objective Lens Aberration Correction via Moving Group
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dry objectives with high numerical aperture struggle to provide good aberration performance across a wide field of view and a wide range of wavelengths, particularly in biological microscopes, due to insufficient correction of axial chromatic aberration and off-axis aberrations.
Innovation Solution
A dry objective design incorporating a first lens group with positive refractive power and a second lens group with negative refractive power, featuring a moving lens component that satisfies specific conditional expressions to correct aberrations, including numerical aperture, depth of focus, and wavefront aberrations, thereby enhancing resolution and chromatic aberration correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional dry objective with high numerical aperture is used, then the resolution is improved, but the aberration performance across a wide field of view deteriorates
Solution Approach 1:
The objective lens is divided into multiple lens groups (first lens group with positive refractive power, second lens group with negative refractive power, and moving lens component) that can independently correct different types of aberrations. This segmentation allows each group to specialize in correcting specific aberrations while maintaining high numerical aperture for resolution.
Solution Approach 2:
A moving lens component is introduced that can shift along the optical axis to dynamically correct spherical aberration based on the thickness of the cover glass. This dynamic adjustment mechanism enables the objective to maintain optimal aberration correction across varying observation conditions while preserving high resolution.
2Measurement precision
If a conventional dry objective with high numerical aperture is used, then the resolution is improved, but the chromatic aberration correction deteriorates
Solution Approach 1:
The objective employs multiple lens elements with different refractive indices and dispersion characteristics (including fluorite lenses with high Abbe numbers and ordinary glass lenses with lower Abbe numbers). This composite lens structure enables effective correction of axial chromatic aberration across a wide wavelength range while maintaining high numerical aperture for resolution.
3Measurement precision
If a conventional dry objective with high numerical aperture is used, then the resolution is improved, but the off-axis aberration correction deteriorates
Solution Approach 1:
Different lens groups are designed with specific local functions: the first lens group with positive refractive power corrects off-axis aberrations such as coma and astigmatism, while the second lens group with negative refractive power corrects field curvature. This localized correction approach enables high resolution at the center and periphery of the field of view simultaneously.
4Measurement precision
If the numerical aperture is increased to improve resolution, then the depth of focus decreases, but the working distance is reduced
Solution Approach 1:
The objective design separates the functions of different lens groups along the optical axis to independently optimize numerical aperture for resolution and working distance. The first lens group positioned closer to the object provides the high numerical aperture, while the second lens group positioned closer to the image plane extends the working distance, effectively decoupling these parameters through spatial arrangement.
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 objective achieves improved resolution and aberration correction across a wide field of view and wavelength range, effectively addressing the limitations of conventional designs by optimizing numerical aperture, depth of focus, and chromatic aberration performance.
Implementation Method 1
the first lens group having a positive refractive power that converts a divergent pencil of light from an object point into a convergent pencil of light
Implementation Method 2
a moving lens component that moves along an optical axis and satisfies the following conditional expressions: 0.85≤NAob×|β|≤20 mm, where NAob is a numerical aperture of the dry objective, β is a magnification of the objective
Data Source
AI summary
A dry objective including the first lens group having a positive refractive power that converts a divergent pencil of light from an object point into a convergent pencil of light and the second lens group having a negative refractive power. The objective includes a moving lens component that moves along an optical axis and satisfies the following conditional expressions of:0.85≤NAob<1.0 (1); and9 mm≤Yreso×|β|≤20 mm (3),where NAob is a numerical aperture, Yreso is a maximum object height in a region in which a value obtained by dividing RMS wavefront aberration at the e-line by a wavelength of the e-line is 0.2 or smaller, the region being on a plane that is orthogonal to the optical axis and intersects with an on-axis position at which the RMS wavefront aberration at the e-line is minimized, and β is a magnification of the objective.