Main Parameters And Application Areas of Industrial Microscope Lenses

As a core component of industrial microscopes, industrial microscope lenses are also key parts of machine vision inspection systems and precision measuring equipment. They are mainly used for close-range, high-precision observation and inspection of workpieces, and their key parameters directly determine image quality and applicable scenarios.

In this article, we will learn about the relevant knowledge of industrial microscope lenses.

1.Main parameters of industrial microscope lenses

The main function of industrial microscope lenses is to magnify tiny objects, making their details clearly visible for easy observation, analysis, and measurement. When selecting and applying them, the following key parameters should be considered:

(1)Magnification

Magnification refers to the number of times an image is magnified relative to the actual object, directly affecting the lens's field of view and detail resolution. Common magnification ranges from 0.5× to 200×, with 2×, 4×, 5×, 10×, and 20× magnifications frequently used in industrial inspection.

Generally, lower magnification provides a wider field of view, suitable for macroscopic observation; higher magnification can resolve micrometer-level details, but offers an extremely small field of view.

(2)working distance

Working distance (WD) refers to the distance (in mm) from the front of the lens to the object being measured, and it directly affects the spatial adaptability of the inspection equipment. In automated production lines, the appropriate working distance is generally determined based on factors such as the robotic arm's operating space and the size of the inspection table.

Under normal circumstances, the working distance for low-magnification lenses is typically >10mm, while for high-magnification lenses it may be <1mm. Industrial scenarios often require a longer working distance (generally >30mm) to allow for operating space between the lens and the sample, adapting to the automation requirements of the production line.

Working distance of industrial microscope lenses

(3)Numerical aperture

Numerical aperture (NA) directly determines the resolution and image brightness of a lens. Generally, the larger the NA value, the higher the resolution and the shallower the depth of field. Lenses with high NA values have high resolution and are suitable for detecting minute defects; lenses with low NA values are suitable for scenarios requiring a wider field of view.

(4)Resolution

Resolution is the smallest detail that a lens can clearly resolve, and it is a core indicator of image sharpness, primarily determined by numerical aperture (NA). For example, oil immersion lenses with high NA provide excellent image resolution.

In precision inspection scenarios, a lens with an appropriate resolution must be selected based on the characteristic dimensions of the object being inspected.

(5)Field of view

The field of view is the maximum area that a lens can capture. Generally, the higher the magnification, the smaller the field of view.

(6)Depth of field

Depth of field is the vertical distance a sample can move forward or backward while maintaining image sharpness, and it is affected by factors such as aperture, focal length, and working distance. Generally, the longer the lens's working distance, the greater the depth of field; the larger the NA value, the greater the magnification, and the shallower the depth of field.

Key parameters of industrial microscope lenses

(7)Distortion rate

Distortion rate is a measure of the geometric error in the image formed by a lens. Industrial microscope lenses typically have extremely low distortion rates, which is crucial for precision dimensional measurements.

(8)Mount type

The type of lens mount determines the compatibility between the lens and the camera. Common mount types include C-mount, CS-mount, and F-mount; the appropriate mount must be selected based on the available equipment. Standard microscope lenses commonly use the C-mount, which is compatible with small cameras and is most frequently used in machine vision.

(9)Sensor size

Common lens sensor sizes, such as 1/2.5", 1/1.8", 1", 1/2", and 1/3", must match the sensor size of industrial cameras. Under normal circumstances, the maximum compatible sensor size of the lens must be greater than or equal to the camera sensor size; otherwise, the edges of the image will appear dark, affecting image quality.

The selection of sensor size is important for industrial microscope lenses

2.Types of industrial microscope lenses

Depending on the application requirements, industrial microscope lenses are commonly classified in the following ways:

(1)Classified by magnification

①Low-magnification lenses: The magnification is usually between 1x and 10x, and they are suitable for observing larger objects or overall structures.

②Medium magnification lens: Magnification between 10x and 50x, suitable for observing medium-sized details.

③High-magnification lenses: Magnification of 50x-1000x or higher, suitable for observing tiny details or microstructures.

(2)Classified by working distance

①Long working distance lens: The working distance is relatively long, which is suitable for observing spaces with height or requiring operation.

②Short working distance lens: The working distance is relatively short, making it suitable for high-magnification observation.

(3)Classified by optical design

①Achromatic lenses: Correct for chromatic aberration and suitable for general observation.

②Semi-apochromatic lenses: further correct chromatic aberration and spherical aberration, resulting in higher image quality.

③Apochromatic lenses: Highly correct for chromatic aberration, spherical aberration, and astigmatism, providing the best image quality and suitable for high-precision observation.

(4)Classified by special function

①Polarizing lens: used to observe materials with birefringence properties, such as crystals and fibers.

②Fluorescent lens: Used to observe fluorescently labeled samples, commonly used in the biomedical field.

③Infrared lens: Used for observation under infrared light, suitable for the analysis of special materials.

Types of industrial microscope lenses

3.Application areas of industrial microscope lenses

Industrial microscope lenses are widely used in automated machine vision production, primarily for inspecting the appearance quality and minute defects of products moving at high speeds on manufacturing lines—defects that are often difficult to detect with the naked eye. Below is a detailed look at some of the main application areas:

(1)Semiconductors and integrated circuits

Industrial microscope lenses are commonly used in semiconductor manufacturing for detecting particles and scratches on wafer surfaces, monitoring photolithography processes, and analyzing and locating defects and failures within chips.

Defect identification in this field requires lenses with micron- or sub-micron-level precision, and typically necessitates high resolution, low distortion, good planarity, and a stable mechanical interface.

(2)Electronic manufacturing and PCB inspection

In the electronics manufacturing industry, industrial microscope lenses are commonly used to inspect PCB solder joints, open circuits, short circuits, and other defects. Utilizing continuous zoom capabilities, they can quickly complete the entire inspection process, from scanning the entire board to magnifying specific solder joints.

Combined with autofocus, they can achieve precise defect location. Applications in this field typically require lenses with a wide field of view, continuous zoom, and anti-static coating.

(3)Precision manufacturing and quality control

In high-precision manufacturing fields such as aerospace, medical devices, and automobile manufacturing, industrial microscope lenses, combined with two-dimensional measuring equipment or flash measuring instruments, can achieve non-contact, rapid dimensional measurement, controlling measurement errors within an extremely small range (e.g., within 0.01mm), ensuring the processing quality of critical components.

For example, in dimensional measurement, it can perform high-precision measurement of the dimensional tolerances of precision parts, such as gear tooth pitch, thread pitch, and mold cavity dimensions.

Industrial microscope lenses are commonly used in high-precision manufacturing

(4)Materials science fields such as metallic materials

Industrial microscope lenses can be used to analyze the relationship between the microstructure and macroscopic properties of materials. They are commonly used for observing the metallographic structure of metals, alloys, ceramics, and composite materials, as well as for observing coating thickness and analyzing fracture failure.

For example, for metallic materials, they are often used to observe the metallographic structure, such as grain boundaries, inclusion distribution, and phase transformations; for new materials, they can be used to analyze the morphology, structure, and interfacial bonding state of nanomaterials and composite materials.

(5)Machine vision and automation

Industrial microscope lenses are used in machine vision systems to achieve object recognition, positioning and grasping, deviation correction, and conveying control. As the eyes of automated production lines, they are commonly used to perform online inspection tasks.

For example, in the food, pharmaceutical, and packaging industries, they are used for detecting product appearance defects and dimensional sorting.

(6)Biomedical and scientific imaging

In the biomedical field, industrial microscope lenses are commonly used for cell and tissue observation, examining biological samples such as cells, tissues, pathological sections, and microorganisms, and assisting in microbial culture monitoring and drug screening.

In the field of scientific research, industrial microscope lenses are often used for observation and experimental analysis. These applications require lenses with high color fidelity and low-noise imaging capabilities.

Industrial microscope lenses are commonly used for biomedical and scientific imaging

4.Maintenance and care of industrial microscope lenses

To extend the lifespan of industrial microscope lenses, the following maintenance precautions should be taken during routine use:

①Clean the lens: Use a dedicated lens cleaning cloth and cleaning solution to clean it, avoiding scratching the lens.

②Avoid collisions: Handle with care during use to avoid impacts to the lens.

③Dust and moisture protection: When storing, be sure to use a dust cover to prevent the lens from getting damp or dusty.

④Regular inspection: Regularly check the performance and condition of the lens, and repair or replace it in a timely manner.

In conclusion, when selecting an industrial microscope lens, it is necessary to consider the specific needs of different application fields, combine lens parameters and performance, and choose the best-matched lens to maximize its value and provide a solid guarantee for precision manufacturing and scientific research.

Final Thoughts:

By working with professionals at ChuangAn, both design and manufacturing are handled by highly skilled engineers. As part of the purchasing process, a company representative can explain in more detail specific information about the type of lens you wish to purchase. ChuangAn's series of lens products are used in a wide range of applications, from surveillance, scanning, drones, cars to smart homes, etc. ChuangAn has various types of finished lenses, which can also be modified or customized according to your needs. Contact us as soon as possible.