In the field of machine vision and industrial inspection, the lens is a key component for obtaining image information, and its performance directly affects the inspection accuracy and efficiency. Varifocal Lens and Varifocal Lens as a common two types of lenses, imaging principle and application performance are different, Varifocal Lens through the internal lens to move to change the focal length, to achieve continuous scaling of the shooting screen, stable imaging quality; Varifocal Lens through the change of the magnification of a specific lens group to achieve the stage of doubling, the optical structure of the big changes.

Differences in imaging principles

1. Varifocal Lens

Varifocal Lens changes the focal length of the lens through the coordinated movement of multiple groups of lenses inside the lens. Take the common optical Varifocal Lens as an example, when the lens is adjusted from the wide-angle end to the telephoto end, the lens group inside the lens moves along the direction of the optical axis, and the optical structure of the lens changes, and the point of convergence of the light also changes, thus changing the imaging angle of view and magnification to realize the continuous zoom of the shooting screen. In this process, the lens always maintains the focusing adjustment of light to ensure that images at different focal lengths can be clearly imaged on the image sensor to maintain stable imaging quality.

2、Zoom lens

A zoom lens achieves magnification primarily by changing the magnification of a specific lens group inside the lens. It is usually based on the switching of a few fixed optical components to achieve different magnification changes, such as from 2x to 4x to 8x. Each time the zoom is changed, the optical components inside the lens are reassembled, the optical structure is greatly changed, and the light propagation path and focusing method are adjusted accordingly to adapt to the imaging needs under different magnifications. Unlike Varifocal Lens, which changes continuously, the doubling of a zoom lens is staged.

Differences in application areas

Varifocal Lens

1. Large workpiece size measurement: In the machinery manufacturing, automotive parts production and other industries, the size measurement of large workpieces is a key link. Varifocal Lens by virtue of its continuously variable focal length characteristics, can be flexibly adjusted to the shooting range and angle of view, from a distance to the overall view of the large workpiece, quickly obtain the overall picture of the workpiece, and then through the zoom closer to the key parts of the details of the shooting and measurement, without the need for frequent replacement of the lens or adjust the position of the equipment, to improve the efficiency and accuracy of the measurement. For example, in the inspection of automobile engine block, Varifocal Lens can be utilized to measure the size of each part of the cylinder block from different angles and at different focal lengths to ensure that the product meets the design requirements.

2. Dynamic inspection scenarios: In automated production lines, products move at high speeds, requiring real-time detection of defects in product appearance, assembly quality, etc.. The fast Varifocal Lens enables it to quickly capture the details of different parts of the dynamic product, without affecting the speed of the production line under the premise of a full range of product inspection. For example, in the assembly line of electronic products, Varifocal Lens can quickly track and detect the moving circuit board, timely detection of missing components, bad solder joints and other issues.

Zoom Lens

1. Precision Electronic Component Inspection: In the field of electronic chip manufacturing, tiny parts processing, etc., the requirements for inspection accuracy are extremely high. Variable-magnification lens can provide multiple high magnification observation, from low magnification of the chip or parts of the overall layout of the view, and quickly switch to high-magnification state of the chip line, welded joints, parts and components of the surface of the microscopic defects such as detailed detection, clearly presenting the tiny details, to meet the needs of precision inspection. For example, in the chip package inspection, the zoom lens can help inspectors accurately identify the chip pin soldering, short circuit and other issues.

2. Complex structure internal inspection: For some industrial products with complex internal structure, such as the internal components of aviation engines, pipelines, etc., the variable-magnification lens with endoscope and other equipment can go deep into the product, from low macro-observation of the internal structure, switching to high-magnification of the key parts of the defects detected, providing detailed and accurate image information for product quality assessment.