As a combination of software and hardware in industrial and non-industrial fields, machine vision mainly includes imaging and image processing, which is mainly composed of light source and light source controller, camera lens, industrial camera, visual control system, etc. Its main function is to capture and process images, and provide operation guidance for the execution of equipment.
With the rise of global Industry 4.0, the informatization transformation of manufacturing industry has become the general trend. When human eye cannot meet the needs of modern rapid development, machine vision, as the application direction of intelligence and automation, naturally carries the banner of manufacturing modernization.
And machine vision as a replacement for human eye detection, brightness and accuracy are naturally the top priority.
Brightness of image
When machine vision is working, the brightness of the captured image is determined by many factors, such as light source, camera aperture, exposure time, and coaxiality of light and Sensor.
As a lighting device, the output power and lighting mode of the light source will directly affect the brightness and uniformity of the target, and indirectly affect the quality and stability of the image.
Circle of light
The size and design structure of the aperture will have a direct impact on the amount of light entering. The larger the aperture is, the more reasonable the structure design is, the more sufficient the amount of light entering will be guaranteed and the glare/halo phenomenon will be effectively reduced.
Exposure to light
For industrial cameras, the exposure time should be sufficient so that the light can stay on the Sensor for a long enough time.
Light and Sensor coaxicity
The coaxiality of light and Sensor is often the most overlooked item. For example, the brightness and darkness of the middle and edge of the image are different, and it is difficult to identify when the consistency is poor, while it is relatively easy to identify when the consistency of the features in the image is good.
Therefore, for the coaxiality of light and Sensor, in addition to the light source product and placement position, the industrial camera will also be required to have good optical axis consistency.
Accuracy of image
Image accuracy is a more important measure of image quality, generally depends on the camera resolution and camera frequency.
Resolution of resolution
The smallest unit of measurement for a digital image is the pixel, which itself does not represent the actual size of the subject.
The “accuracy” usually required, in fact, refers to a pixel can represent the size of the object, at this time only need to divide the camera pixel size by the magnification of the lens (accuracy = pixel size ÷ optical magnification, or with the field of view ÷ the number of pixels, the result is the same).
So the higher the resolution, the finer the image.
Just as the human eye sees a moving object, when the object moves too fast, the human eye cannot clearly observe the whole movement of the object. And the camera also has this kind of shooting speed limit, called the camera dominant frequency. When the running speed of the subject exceeds the upper limit of the main frequency of the camera, the visual detection equipment naturally cannot obtain a complete and clear image.
Therefore, the higher the main frequency of the camera, the faster the acquisition speed, the higher the image quality.
3, SONY FCB-EW9500H
SONY FCB-EW9500H uses 1/1.8 Starvis™ CMOS 4.17-megapixel image sensor with 7 petals aperture, which can effectively reduce glare/halos and other phenomena, and has excellent optical axis consistency.