Microscope Objective with Cemented Lens Groups

Solution Overview

Problem

Microscope objectives with high numerical aperture greater than 1.2 and using immersion oil have higher production costs due to complex and expensive manufacturing processes, particularly for two-part cemented elements.

Innovation Solution

Design of three microscope objective variants of the 'planachromat' class with an optical magnification of −100 and a visual field factor of 20, comprising 9 lenses with 3 cemented elements, optimized to reduce production costs through repetitive components and improved image contrast by correcting spherical aberration, coma, astigmatism, and chromatic aberration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a two-part cemented element is used in the front part of the objective, then the numerical aperture can be greater than 1.2, but the production costs increase due to complex manufacturing

Engineering Contradiction:

Improvenumerical apertureVSAvoidproduction costs

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The objective is divided into modular groups of lenses, where the front part consists of a hemisphere lens that can be manufactured separately and then cemented to the remaining lens groups. This segmentation allows the complex high-NA objective to be produced in manageable sections, reducing overall manufacturing complexity and cost.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple lens groups are combined with the hemisphere lens to achieve the required optical performance. The hemisphere lens is cemented to subsequent lens groups to form a complete objective system that achieves NA > 1.2 while maintaining cost-effectiveness through standardized manufacturing processes.

Inventive Principle:

Principle #5Merging (Combining)

2Measurement precision

If a two-part cemented element is used in the front part of the objective, then the numerical aperture can be greater than 1.2, but the manufacturing process becomes complex and expensive

Engineering Contradiction:

Improvenumerical apertureVSAvoidmanufacturing process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The objective is divided into modular groups of lenses, where the front part consists of a hemisphere lens that can be manufactured separately and then cemented to the remaining lens groups. This segmentation allows the complex high-NA objective to be produced in manageable sections, reducing overall manufacturing complexity and cost.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hemisphere lens is manufactured and prepared in advance as a separate component with precise specifications. This preliminary preparation allows for standardized production of the front element, which can then be efficiently assembled with the remaining lens groups, reducing overall manufacturing complexity.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If a single hemisphere lens is used in the front part of the objective, then the production costs are reduced, but the image contrast may be compromised

Engineering Contradiction:

Improveproduction costsVSAvoidimage contrast

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

Multiple lens groups are combined with the hemisphere lens to achieve the required optical performance. The hemisphere lens is cemented to subsequent lens groups to form a complete objective system that achieves NA > 1.2 while maintaining cost-effectiveness through standardized manufacturing processes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The optical parameters of the lens groups are carefully designed and optimized to correct aberrations and maintain image contrast. By adjusting curvature radii, thicknesses, and material properties of the individual lens groups, the system achieves high image quality despite using a cost-effective single-element front lens.

Inventive Principle:

Principle #35Parameter changes

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 solution achieves a significant reduction in production costs while maintaining high image quality, with image field flattening and aberration correction, allowing for flexible and cost-effective production of microscope objectives with a numerical aperture of 1.25.

Implementation Method 1

The microscope objective consists of 9 lenses comprising 3 cemented elements

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

the coincidence in focal position of the spectral lines C' and F'

Methodology Applied

Scientific EffectFocusing: Focusing

Data Source

PatentUS7907348B2Microscope objective

Publication Date: 2011.03.15 CARL ZEISS MICROSCOPY GMBH

AI summary

The invention relates to a microscope objective with preferably anti-symmetric lenses or lens groups with an optical magnification of −100 and a visual field factor of 20.According to the invention the microscope objective consists of 9 lenses with 3 cemented elements, starting from the object side (left), a lens which is almost a hemisphere L1 with positive refractive power, a meniscus lens L2 with positive refractive power, a two-part cemented element G1 with positive refractive power, another two-art cemented element G2 with positive refractive power, a two-part cemented element G3 with negative refractive power, and finally a meniscus lens L9 with negative refractive power.By using cemented elements and lens pairings of the same construction, production costs can be reduced compared with methods of the prior art while image contrast is improved.