Optical lens technology is based on an important part of computer science. It is designed in a wide range of fields, including computer, image processing, artificial intelligence, signal processing, pattern recognition and other technical content. Since its birth, it has been more than 30 years old. With the progress of industrial automation, machine identification technology has gradually improved from function and has been successfully applied to industry. Among them, CCD industrial cameras, smart cameras, ARMFPGA, image processing and other technologies have developed rapidly, which has greatly promoted the development of spherical/aspherical/cylindrical/paraboloid optical lens.
Simply put, the essence of optical lens technology is to use the machine instead of the human eye to perform various operations and judgments. Greatly saved labor, improved work efficiency, relatively standardized work, and significantly reduced error rate.
What is an industrial machine vision system?
It is the operating system designed by using optical lens technology. The system generally includes a light source, a lens, a CCD camera, an image acquisition card, and image processing software.
Vision light source: Basically, it is an important factor affecting the input of the procurement high efficiency thin-film multilayer optical filter system. It directly affects the quality and application effect of the input data. For each specific application instance, choose the appropriate lighting device to achieve the desired result. Its light source can be divided into visible light and invisible light. Several commonly used sources of visible light are white, fluorescent, mercury, and sodium. On the other hand, ambient light may affect the quality of the image, so the PC-based solution can be used mainly for electronic production test equipment, which has the advantages of high performance, high flexibility and high cost performance, which is very suitable for high difficulty, high resolution and High speed optical lens application. Therefore, a protective screen can be added to reduce the influence of ambient light. The illumination system can be divided into: backlight, forward illumination, structured light and stroboscopic illumination according to its illumination method. Among them, the back illumination is placed between the light source and the camera, and has the advantage of obtaining a high contrast image. The forward illumination is that the light source and the camera are located on the same side of the object to be tested, which is convenient for installation. The structured light illumination projects a grating or a line source or the like onto the object to be measured, and demodulates the three-dimensional information of the object to be measured according to the distortion generated by them. The stroboscopic illumination is to illuminate a high-frequency light pulse onto an object, and the camera capture requires synchronization with the light source.
Optical lens: lens selection should pay attention to focal length, target height, image height, magnification, distance from image to target, center point / node and distortion. Common classification: divided by color according to imaging color, can be divided into color camera and black and white camera; divided by resolution, the number of pixels below 380,000 is ordinary type, the number of pixels is higher than 380,000; Dimensional division can be divided into 1/4, 1/3, 1/2, 1 inch cameras; divided by scanning method, can be divided into line scanning camera (line array camera) and surface scanning camera (area camera) (Surface scanning camera can be divided into interlaced scanning camera and progressive scanning camera); divided by synchronous mode, can be divided into ordinary camera (internal synchronization) and camera with external synchronization function.
Optical lens: According to different standards, it can be divided into standard resolution digital camera and analog camera. Different cameras and high-resolution cameras should be selected according to different practical applications: line scan CCD and area array CCD; monochrome camera and color camera.
Image capture card: The image capture card is just one component of a complete customizable large size optical prism system, but it plays a very important role. The image acquisition card directly determines the interface of the camera: black and white, color, analog, digital, and so on. Typical is a PCI or AGP-compatible capture card that can transfer images to computer memory for processing. Some capture cards have built-in multiplexers. For example, you can connect 8 different cameras and then tell the capture card to capture the information captured by that camera. Some capture cards have built-in digital inputs to trigger the capture card to capture, and the digital output activates the gate when the capture card captures the image.
The output of the optical lens is not an image video signal, but a directly obtained detection result (such as data such as size) after arithmetic processing. In general, the optical lens test uses a machine instead of an artificial naked eye to make measurements and judgments. The captured target is first converted into an image signal by a CCD camera, transmitted to a dedicated image processing system, and converted into a digitized signal based on pixel distribution, brightness, color, and the like. The image system performs various operations on these signals to extract features of the target, such as area, length, number, position, and so on. Then, according to the preset tolerance and other conditions, the output results, such as: size, angle, offset, number, pass/fail, presence/absence, etc.