Industrial camera is a key component in the machine vision system, and its most essential function is to convert optical signals into ordered electrical signals. Choosing the right camera is also an important part of machine vision system design. The choice of camera not only directly determines the captured image resolution, image quality, etc., but also is directly related to the operation mode of the whole system.
Industrial cameras are mainly composed of the following parts:
1. Image sensor: the core component of the industrial camera, usually using CMOS or CCD sensors.
2. Camera circuit board: including image sensor control chip, A/D conversion, USB or GigE interface and so on.
3. Lens: responsible for focusing the light reflected from the object onto the sensor.
4. Filter: used to filter out unwanted light.
5. Light source: Provides proper lighting conditions to ensure high quality images are captured.
6. Housing: Usually made of metal to protect the internal electronic components from damage.
7. Other auxiliary components: such as fans, heat sinks, power supplies, etc. to ensure the normal operation of industrial cameras.
Industrial camera selection
Suitable industrial camera selection and selection in the machine vision system is very important, industrial camera suitable or not directly determines the results of the entire machine vision system operation. Since the choice and selection of industrial camera is so important, how to choose the right industrial camera? In order to help the demand for industrial cameras, the following degree Shen Technology will talk about industrial camera selection methods, from which dimensions to start so that the demand for the selection of suitable for their own industrial cameras.
1. Application scenarios
There are many industrial application scenarios, such as surface defect detection, object positioning detection, rapid scanning detection, etc. These different application scenarios on the industrial camera pixels, frame rate, spacing, light and other parameters have different requirements.
For example, surface defect detection requires high light and pixel clarity, item positioning detection requires precision identification and algorithms, and fast scanning detection requires high frame rate and speed in addition to clarity. Even for the same object surface defect detection, metal surface detection and cloth, paper surface detection on the industrial camera requirements are also very different.
Metal surface will reflect, so the metal surface inspection of the light source requirements are higher, and industrial cameras should be able to recognize the light and dark surface. Cloth, paper surface inspection of the color, material, clarity requirements are higher. So the application scenario determines what kind of industrial camera should be used.
2. Selection of resolution
Resolution, usually refers to the number of pixels contained in the image sensor, expressed in length * width. We all know that 1 megapixel, 5 megapixel, 10 megapixel, and even more than 100 million pixels are calculated from the resolution.
Choosing the resolution is a matter of considering two things:
Determine the precision of the target. If the target accuracy cannot be determined, the choice of resolution is empty words. Industrial camera pixel accuracy = unidirectional field of view size / camera unidirectional resolution. In addition industrial camera pixel accuracy must be higher than the target's required accuracy, so as to have practical measurement meaning.
The output of the industrial camera, VGA or USB output, has a high requirement for the resolution of the monitor. If the resolution of the industrial camera is higher than the resolution of the monitor, the advantage of high resolution of the industrial camera will not be shown. All-in-one observation machine (including software analysis and identification), there is no worry in this regard, the natural resolution is the higher the better.
3. Frame rate selection
Frame rate, the full name is frame rate, refers to the number of frames per second of the collected image, in layman's terms is the camera per second kind of how many photos can be taken. The choice of frame rate is to look at the speed of movement of the object to be measured, the speed of the choice of high frame rate of industrial cameras. If the speed is high, choose an industrial camera with a high frame rate, and if the speed is high, choose a camera with a low frame rate.
If in the actual application scenario, both high resolution requirements, but also want a high frame rate, the need to find a larger bandwidth bus, that is, the output interface of the industrial camera.
4. Chip selection
Industrial camera from the chip, there are two kinds of CCD and CMOS, CMOS chip in the same imaging quality, because of lower costs and lower power consumption in the market has replaced the CCD chip, only in some higher collection speed, higher quality images and resolution of the application of the scene, the use of the CCD will be better.
5. Shutter and exposure options
Camera in the shutter is used to control the light irradiation photoreceptor exposure time of the device, to protect the camera's internal chip is not affected by incident light, only in the exposure will be open. Exposure is controlled through the shutter, and global shutter and shutter roll are the two most common shutter methods used in industrial cameras. If it is used for dynamic shooting (fly shooting), you need to use the global shutter; static shooting is only suitable for rolling shutter.
6. Transmission interface selection
Transmission interface is a good picture taken by the industrial camera transmission to the computer side of the transmission protocol, different interfaces to capture the transmission speed is not the same, the common GigE (commonly known as Gigabit network camera), USB3.0 (commonly known as USB3.0 camera), CameraLink.
7. Color options
Industrial cameras are available in color and black and white. Generally industrial cameras choose black and white is good, to meet the needs of most application scenarios, industrial cameras choose color only when there is a need to identify the color of the situation. And choose a black and white industrial camera, to avoid the conversion from color to black and white images and then computing this step to simplify the process, can to a certain extent to improve the image quality.
8. Brand selection
Good brand represents excellent product quality, excellent after-sales service, complete technical support, this point in the industrial camera industry is no exception. Although the industrial camera is the main thing is to look at the collected image results, but a good brand for enterprises and factories to save effort, reduce the use of unnecessary trouble.
Industrial camera selection methods, from the above eight dimensions for you to analyze. From their own application scenarios, external factors and internal conditions combined with each other, for their own selection of the most economical, worry-free, labor-saving, effective industrial camera.