One of the important means by which humans observe and recognize this world is vision. With the development of technology and information technology, humans have gradually acquired this skill for robots or other intelligent machines. Now, important product functions in machine vision systems are gradually improved, such as lenses, cameras, light sources, image processing software, and visual sensors .

Compared with computer vision, computer vision is mostly used to identify "people", while machine vision is mostly used to identify "things". Machine vision is more focused on engineering. It can automatically acquire and analyze images. It requires higher accuracy and speed. The resolution of general machine vision is also much higher than that of computer vision. It usually requires real-time processing.

        What is a machine vision system?

The visual system is to use the machine instead of the human eye for measurement and judgment. The vision system converts the image signal into a digital signal; the image processing system performs various operations on these signals to extract the characteristics of the target, such as area, number, width, height, etc., and then obtains the output according to the preset conditions, including the size , Angle, number, whether qualified, yes / no, etc.

The characteristic of the machine vision system is to improve the flexibility and automation of production. In some occasions that are not suitable for dangerous working environments or artificial vision that is difficult to meet the requirements of manual work, machine vision is often used to replace artificial vision; at the same time, in large-scale industrial production processes, manual inspection of product quality is low in efficiency and high error rate Using machine vision system can greatly improve production efficiency. Moreover, machine vision is easy to realize information integration, and it is the basic technology to realize computer integrated manufacturing. Products can be measured, guided, detected, and identified on the fast production line to better complete production tasks.

A complete machine vision system includes the following products:

       1. Camera

       Industrial cameras are a key component in machine vision systems, and different types of cameras and cameras with different resolutions should be selected according to different application scenarios. The choice of camera not only directly determines the resolution and quality of the collected images, but also directly relates to the operating mode of the entire system.

2. Light source

The light source is one of the key parts of machine vision applications. It is divided into visible and invisible light. Its main goal is to project light onto the measured object in a suitable way, highlighting the contrast of the measured feature part, and making the measured area more Clear and accurate form response. Therefore, different light sources should be selected for different practical applications.

       3. Lens

       In the machine vision system, the main function of the lens is to place the imaging target on the photosensitive surface of the image sensor, and the basic function of the lens is to realize beam conversion (modulation).

       Select the appropriate type (telecentric / ordinary) according to the required accuracy (high / low) of the test product; the telecentric lens selects the model according to the field of view required by the test product; the ordinary lens selects the model according to the working distance and product field of view; , You need to choose other types of lenses, such as high magnification lenses.