Microscope Image Forming Lens Chromatic Aberration Correction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image forming lenses for microscopes fail to adequately correct chromatic aberration across a wide wavelength range and do not prioritize high transmittance, especially when observing fluorescent markers with varying wavelengths, which limits resolution and contrast in biological research.

Innovation Solution

An image forming lens design comprising a first lens group with positive refractive power and a second lens group with negative refractive power, using specific glass materials and configurations to satisfy conditional expressions for refractive indices, partial dispersion ratios, and transmittance requirements, ensuring effective chromatic aberration correction and high transmittance across a wide wavelength range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional image forming lens designs are used, then the lens structure is simple, but chromatic aberration is not sufficiently corrected across wide wavelength ranges

Engineering Contradiction:

Improvechromatic aberration correctionVSAvoidlens group configuration

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The lens is divided into two distinct lens groups: a first lens group with positive refractive power and a second lens group with negative refractive power. This segmentation allows each group to be optimized for specific wavelength ranges, with the first group handling shorter wavelengths and the second group handling longer wavelengths, thereby achieving comprehensive chromatic aberration correction across the visible spectrum

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different glass materials with specific refractive indices and dispersion characteristics are assigned to different lens groups. The first lens group uses glass materials optimized for correcting chromatic aberration in shorter wavelengths, while the second lens group uses glass materials optimized for longer wavelengths. This local optimization of material properties enables effective correction across the entire wavelength range

Inventive Principle:

Principle #3Local quality

2Reliability

If conventional lens materials are used, then manufacturing is easier, but transmittance in ultraviolet and infrared regions is insufficient

Engineering Contradiction:

ImprovetransmittanceVSAvoidglass material selection

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs composite lens construction using multiple glass materials with complementary transmittance characteristics. By combining glass materials that exhibit high transmittance in different spectral regions, the lens achieves broad-spectrum transmittance from ultraviolet through visible to infrared wavelengths, overcoming the limitations of single-material lenses

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If fluorescent markers with close wavelengths are used, then fewer markers are needed, but wavelength discrimination becomes impossible

Engineering Contradiction:

Improvefluorescent marker compatibilityVSAvoidwavelength discrimination

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The lens design provides dynamic focus adjustment capability across different wavelength ranges, allowing the optical system to adaptively optimize focus for each fluorescent marker's emission wavelength. This dynamic focusing capability enables precise discrimination between markers with close wavelengths by adjusting the focal plane for each specific wavelength

Inventive Principle:

Principle #15Dynamics

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 lens design effectively corrects chromatic aberration and maintains high transmittance, enabling high-resolution and high-contrast imaging of biological samples across a wide wavelength range, particularly suitable for fluorescent observations.

Implementation Method 1

a first lens group having positive refractive power; and a second lens group having negative refractive power

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS7864438B2Image forming lens and microscope apparatus using the same

Publication Date: 2011.01.04 NIKON CORP

AI summary

An image forming lens has a configuration that an image forming lens IL for receiving parallel beams of light emitted from an observation target object and emerging from an infinity-designed objective lens of a microscope and forming an image of the observation target object in a predetermined position, is constructed of, in order from an object side, a first lens group G1 having positive refractive power and a second lens group G2 having negative refractive power, and the first lens group is constructed of a positive lens (e.g., a biconvex lens L1) and a negative lens (e.g., a negative meniscus lens L2). Glass materials of the positive lens and the negative lens configuring the first lens group G1 satisfy conditions of predetermined νdht and partial dispersion ratio Pht, then a transmittance, with respect to the light having a wavelength of 340 nm, of each of the glass materials of all the lenses is equal to or larger than 50% per glass thickness of 10 mm, and the transmittance with respect to the light having the wavelength of 360 nm is equal to or larger than 80% per glass thickness of 10 mm.