Advantages of Multi-Magnification Line Scan Lens in Vision Applications

What is the Essence of a Line Scan Lens?

Are you confused about the difference between a line scan lens and a standard industrial lens? The fundamental distinction is that a line scan lens has a larger image circle compared to a typical FA lens. For example, a 2/3-inch FA lens has an image circle of 11mm, and a 1/2-inch lens has an image circle of 8mm. In contrast, an 8K line scan lens typically has an image circle of around 60mm, with some models reaching up to 80mm, which is significantly larger than FA lenses.

Essentially, a line scan lens is a fixed-focus lens with a large image circle. Apart from the difference in image circle size, other differences are primarily related to application.

Why is a Line Scan Lens More Expensive than an FA Lens?

The three main parameters of a lens, often referred to as the lens trinity, are focal length, aperture, and image circle. These parameters are closely linked to the complexity of lens design, manufacturing difficulty, and overall cost.

It is widely known that line scan lens is more expensive than FA lenses primarily due to significantly larger image circle. 

While FA lenses can be optimized for all magnifications, achieving similar optimization across different magnifications for line scan lens would incur a considerably higher cost.

Why is Magnification a Key Factor for Line Scan Lens?

Magnification, specifically the optical magnification (β), is crucial for the application of line scan lens.

When selecting a line scan lens, it is common practice to first ask the customer for the sensor size and the desired field of view. These parameters are used to calculate the magnification.

Unlike standard industrial lenses, where focal length is often the primary consideration, line scan lens selection prioritizes magnification. This is because the large image circle of a line scan lens makes it challenging to maintain high image quality across different magnifications.

Trends in the Development of Line Scan Lens

In the future, line scan lens will continue to be specialized for different industries. For instance, the printing industry demands high color reproduction accuracy, while the lithium battery industry does not have stringent color accuracy requirements. As customers seek lower costs and higher performance, line scan lens will be further segmented and standardized to meet industry-specific needs. A single lens specification cannot address all application scenarios. Currently, 4K and 8K line scan lens is available in four optimized magnifications, ensuring reliable image quality across various fields of view and working distances.

Furthermore, when selecting a line scan lens, providing just the focal length is insufficient. Additional parameters, including field of view, working distance, and lens mount type, are essential to ensure the chosen lens delivers optimal performance without unnecessary excess capabilities.