Characteristics and applications of machine vision CCD

Machine vision CCD can be called CCD image sensor, also known as image controller. A CCD is a semiconductor device that converts optical images into electrical signals. The tiny light-sensitive substance implanted in the CCD is called a pixel. The more pixels a CCD contains, the higher the resolution it provides. CCD acts like film, but it converts light signals into electrical charge signals. There are many neatly arranged photodiodes on the CCD, which can sense light and convert the optical signal into an electrical signal, which is converted into a digital image signal through an external sampling amplification and analog-to-digital conversion circuit. Its features and applications are as follows:

1. High Resolution: The size of the image point is m-level, which can sense and identify fine objects and improve image quality, from the early 1 inch, 1/2 inch, 2/3 inch, 1/4 inch to the current 1/9 inch, the number of pixels has increased from more than 100,000 pixels in the early stage to tens of millions of pixels, and there is an urgent need to increase in the future.

2. Low Noise and high sensitivity: CCD has very low readout noise and dark current noise, so it has a relatively high signal-to-noise ratio (SNR), and at the same time, it has a high sensitivity of 0.0003, 0.00056LUX and even 0LUX The incident light with low luminosity can also be detected, and its signal will not be masked by noise, so the application of CCD is basically not limited by climate.

3. High Dynamic Range: The dynamic range of the CCD signal processed by digital processing can reach 400%, and the professional grade can reach 600%, which can be applied to both strong light and weak light, improve the use range of the system environment, and do not cause signal contrast due to large brightness differences.

4. Good linear characteristic curve (Linearity): The intensity of the incident light source is proportional to the size of the output signal, which can well reflect the level of detail of the captured image and reduce the cost of signal compensation processing.

5. High Quantum Efficiency: Very weak incident light irradiation can be recorded, and if it is combined with the impact enhancement tube and projector, it can be photographed even in the distant scene at night.

6. Large Field of View: The use of semiconductor technology has been able to manufacture large-area D wafers, and the 35mm wafers with the same size as traditional films have begun to be used in digital cameras and become the key components to replace professional optical cameras.

7. Wide spectral response: from 0.4~1.1μm, it can detect a wide range of light, increase the flexibility of the system, and expand the application field of the system; Depending on the application, a color filter or a composite filter is required;

8. Low image distortion: the use of CCD sensor, the image processing will not be distorted, so that the surface information of the original object can be faithfully reflected;

9. Small size and light weight: CCD has the characteristics of small size and light weight, and is widely used;

10. Low energy consumption, not affected by strong electromagnetic field;

11. Good charge transfer efficiency: the efficiency coefficient affects the signal-to-noise ratio and resolution rate, if the charge transfer efficiency is not good, the image will become blurry;

12. It can be produced in large quantities, with stable quality, sturdy, not easy to age, easy to use and easy to maintain. Some burned-out CCD pixels can recover themselves after a period of live operation.

Application of CCD in the field of industrial visual inspection

1. It can be used for the measurement of geometric quantities of objects. Geometric parameters such as length, width, level, area, etc. can be measured with CCD sensor technology. In addition, CCD technology can also be used in many other occasions, such as multi-dimensional inspection and checking the accuracy of the size, shape, and position and orientation of the packaging label.

2. Online pattern recognition. For example, identify the distributed discrete objects or products transmitted along the automated production line, detect the presence or absence of parts, equip the robot as a vision system, and whether the equipment installation meets the requirements and whether the location is accurate.

3. Automatic detection of the surface of the object. In industrial production, the surface condition is an important factor in the quality of the object, and the use of CCD technology to detect the surface condition of the object with high precision can not only omit the moving parts in the previous optical mechanism scanning method, but also detect high chromaticity, small system structure, and can automatically display or record the surface state of the detected object. Therefore, it can be used in industrial production to detect surface defects of metal plates, plastics, glass, textiles and other items.

4. Processing process detection. Because CCD has high-speed readout ability, it can also be used for detection in the process of processing industry, such as position determination in machine tool processing is an indispensable part of closed-loop control, and the application of CCD technology can realize high-precision real-time control of the position of processing equipment.

Since its establishment, Chengdu Xinxiwang Automation Technology Co., Ltd. has been fully committed to the application and development of machine vision systems, and has provided machine vision inspection equipment, CCD visual inspection systems, CCD visual measurement systems, CCD visual positioning systems, CCD visual inspection connector pin flatness, CCD visual inspection connector pin spacing, CCD visual inspection FFC line mouth size spacing, side width, total width, CCD visual inspection products Lack of materials, missing parts, less parts, CCD visual inspection products, CCD visual inspection to judge the positive and negative of the product, CCD visual inspection of the presence or absence of coding characters, CCD visual inspection of poor coding, CCD visual inspection of laser marking, CCD visual inspection production date, CCD visual character extraction reading recognition, CCD visual screening product mixing model mixing, mobile phone packaging box CCD visual positioning and lamination system, CCD visual appearance inspection system, multiple two-dimensional code reading CCD vision system, CCD visual inspection of scratches, CCD visual product foreign body stain detection, product inner hole CCD visual inspection, CCD visual inner wall defect detection system, CCD visual detection of liquid level height, CCD visual color recognition, CCD visual inspection system CCD appearance defect detection Machine vision system CCD visual online detection, through the machine vision automatic recognition function, so that the dangerous working environment that is not suitable for manual operation or the occasion where artificial vision is difficult to meet the requirements can replace manual work. The highly repetitive inspection work on the assembly line is no longer completed by people, the detection speed and accuracy are improved, the flexibility of production is realized, and the efficiency and automation of production are improved. The company has been adhering to the concept of "professional value creation", with its own successful experience in visual inspection and automation for many years, and strive to provide customers with higher value-added, tailor-made solutions, with the company's professional quality to cooperate with customers, create value together, and achieve a win-win situation. Machine vision system integrator.