How are industrial cameras classified?
Classified by chip structure: CCD cameras & CMOS cameras
Based on sensor structure: Area scan camera & Line scan camera
Classified by output mode: Analog cameras & Digital cameras
Color camera & black and white camera
What are the differences between industrial cameras and regular digital cameras?
Industrial cameras have extremely short shutter speeds, enabling them to capture fast-moving objects clearly, while ordinary cameras capture fast-moving objects very blurry.
Industrial camera image sensors scan line by line, while ordinary camera image sensors scan interlaced lines, or even every three lines.
Industrial cameras have a much higher shooting speed than ordinary cameras; industrial cameras can capture tens to hundreds of images per second, while ordinary cameras can only capture 2-3 images per second.
Industrial cameras output raw data, which typically has a wide spectral range, making them well-suited for high-quality image processing algorithms and widely used in machine vision systems. In contrast, images captured by ordinary cameras have a spectral range suitable only for human vision and are subject to MPEG compression, resulting in lower image quality.
What are the main parameters of an industrial camera?
resolution
Speed (frame rate/line rate)
noise
Signal-to-noise ratio
Dynamic range
Pixel depth
Spectral response
Optical interface
What interfaces do industrial cameras have?
An interface refers to the connection between a camera and a lens. Common lens interfaces include C-mount, CS-mount, and F-mount.
What are the input and output interfaces of an industrial camera?
In machine vision inspection technology, industrial cameras have several input and output interfaces, including Camera Link, IEEE 1394, USB 2.0, Ethernet, and USB 3.0.
What causes frame dropping issues in industrial cameras?
Some machine vision engineers often believe that industrial cameras with USB interfaces cause frame drops. Generally speaking, frame drops in industrial cameras are unrelated to the transmission interface used, whether it's USB, 1394, GigE, or CameraLink. Poorly designed drivers or industrial camera hardware are the real causes of frame drops: frame drops in poorly designed industrial cameras are actually due to data channel congestion, preventing timely processing. Therefore, when a new image arrives, the previous image may be forced to be discarded, or the new image may be forced to be discarded. To solve this problem, designers need to meticulously design every aspect of data transmission between the driver and the industrial camera hardware.
What are the general steps for selecting an industrial camera?
The first step is to know the system's accuracy requirements and the industrial camera's resolution;
The second step requires knowing the system speed requirements and the industrial camera's imaging speed;
The third step requires considering both the industrial camera and the image acquisition card, as this involves their compatibility.
The fourth step is to compare prices.
Knowing the length, width, and height of the object to be measured, as well as the required measurement accuracy, how do you select a CCD camera and industrial lens? What should be considered when choosing these components?
First, you need to choose a suitable lens. The following principles should be followed when choosing a lens:
1) What is the size of the chip in the compatible camera? 2) What type of interface does the camera use: C-mount, CS-mount, or another type? 3) What is the lens's working distance? 4) What is the lens's field of view? 5) What are the lens's spectral characteristics? 6) What is the lens's distortion rate? 7) What are the lens's mechanical dimensions?
When choosing a CCD camera, the following aspects should be considered:
1) Image sensor type: CCD or CMOS; 2) Video characteristics: including point frequency and line frequency; 3) Signal output interface; 4) Camera operating modes: continuous, trigger, control, asynchronous reset, long-time integration; 5) Video parameter adjustment and control methods: manual, RS232.
Also, when choosing a CCD, you should note that 1 inch = 16mm, not 25.4mm.
How can the required camera resolution (in pixels) be calculated based on the precision requirements of a machine vision system?
Knowing the actual detection accuracy allows us to deduce the appropriate pixel count for an industrial camera using the following formulas: X-direction system accuracy (X-direction pixel value) = Field of view (X-direction) / CCD chip pixel count (X-direction); Y-direction system accuracy (Y-direction pixel value) = Field of view (Y-direction) / CCD chip pixel count (Y-direction). Of course, the theoretical pixel value must be determined by considering both system accuracy and sub-pixel methods.
How can we deduce the appropriate industrial camera speed based on the required actual inspection speed?
The system's single-run speed = system imaging (including transmission) speed + system detection speed. Although the system imaging (including transmission) speed can be theoretically calculated based on the industrial camera's asynchronous triggering function, shutter speed, etc., the best method is still to conduct actual testing through software.
How is the resolution of an industrial camera defined?
Resolution is the most fundamental parameter of a camera, determined by the resolution of the chip used in the camera, and is the number of pixels arranged on the chip's target surface. Typically, the resolution of an area scan camera is expressed using two numbers: horizontal and vertical resolution, such as 1920(H) x 1080(V). The first number indicates the number of pixels per row, i.e., 1920 pixels in total, and the second number indicates the number of rows, i.e., 1080 rows. Nowadays, camera resolution is usually expressed in kilobytes (K), such as 1K (1024), 2K (2048), 3K (4096), etc. When acquiring images, the camera's resolution has a significant impact on image quality. When imaging the same large field of view (scene range), higher resolution results in more clearly displayed details.
What do frame rate and line rate mean in industrial cameras?
A camera's frame rate/line rate indicates the frequency at which the camera acquires images. Area scan cameras typically use frame rate, measured in fps (Frames Per Second), such as 30 fps, meaning the camera can acquire a maximum of 30 frames per second. Line scan cameras usually use line rate, measured in kHz, such as 12 kHz, meaning the camera can acquire a maximum of 12,000 lines of image data per second. Speed is a crucial camera parameter, as it's often necessary to image moving objects in practical applications. The camera's speed must meet certain requirements to achieve clear and accurate imaging. The camera's frame rate and line rate are primarily influenced by the frame rate and line rate of the underlying chip, whose maximum design speed is mainly determined by the highest clock frequency the chip can handle.
What does noise mean in industrial cameras?
Noise in industrial cameras refers to unwanted signals outside the actual image target that are not captured during the imaging process. According to the European camera testing standard EMVA 1288, camera noise can be broadly categorized into two types: The first type is statistical fluctuation noise following a Poisson distribution, also called shot noise, which is the same for all cameras and unavoidable, with a well-defined calculation formula (noise squared = signal mean). The second type is inherent noise of the camera itself, independent of the signal. This noise originates from the image sensor readout circuit, camera signal processing and amplification circuits, etc., and the inherent noise varies from camera to camera. **Additionally,** for digital cameras, quantization noise is generated during the analog-to-analog conversion of video signals; the higher the quantization bit depth, the lower the noise.
What does the signal-to-noise ratio (SNR) mean in industrial cameras?
The signal-to-noise ratio (SNR) of a camera is defined as the ratio of signal to noise in an image (the ratio of the average gray value of the effective signal to the root mean square value of the noise). It represents the quality of the image; the higher the SNR, the better the image quality.
What does dynamic range mean in industrial cameras?
A camera's dynamic range indicates the range of light signals it can detect. Dynamic range can be defined in two ways: optical dynamic range, which is the ratio of the maximum light intensity at saturation to the light intensity equivalent to noise output, determined by the characteristics of the sensor; and electronic dynamic range, which is the ratio between saturation voltage and noise voltage. For a fixed camera, its dynamic range is a constant, unchanging with external conditions. In linear response cameras, the dynamic range is defined as the ratio of saturation exposure to noise-equivalent exposure: Dynamic Range = Full-well capacity of the photosensitive element / Equivalent noise signal. Dynamic range can be expressed in multiples, dB, or bits. A larger dynamic range means the camera has a stronger ability to adapt to different light intensities.
What does pixel depth mean in industrial cameras?
The digital signal output by a digital camera, i.e., the pixel grayscale value, has a specific number of bits, called pixel depth. For monochrome cameras, this value is typically 8-16 bits. Pixel depth defines the number of gray levels from dark to bright. For example, for an 8-bit camera, 0 represents complete darkness and 255 represents complete brightness. Numbers between 0 and 25 represent specific brightness levels. 10-bit data has 1024 gray levels, while 12-bit has 4096 gray levels. For each application, we must carefully consider whether we need extremely fine grayscale levels. Increasing from 8-bit to 10-bit or 12-bit can indeed improve measurement accuracy, but it also reduces system speed and increases the difficulty of system integration (more cabling, larger size), so we must choose carefully.
What are the differences between CCD cameras and CMOS cameras?
1. Imaging process
CCD and CMOS image sensors operate on the same principle of photoelectric conversion; their main difference lies in their signal readout processes. Because CCDs have only one (or a few) output nodes for unified readout, their signal output consistency is excellent. In contrast, in CMOS chips, each pixel has its own signal amplifier, performing charge-to-voltage conversion independently, resulting in poorer signal output consistency. However, to read the entire image signal, CCDs require a wide bandwidth from their output amplifiers, while CMOS chips require lower bandwidth for each pixel's amplifier, significantly reducing power consumption. This is the main reason why CMOS chips consume less power than CCDs. Despite this reduced power consumption, the inconsistency of millions of amplifiers introduces higher fixed noise, which is an inherent disadvantage of CMOS compared to CCDs.
2. Integration
From a manufacturing perspective, CCD circuits and devices are integrated onto a single semiconductor crystal material, making the process complex. Only a few manufacturers worldwide, such as DALSA, SONY, and Panasonic, can produce CCD chips. CCDs can only output analog electrical signals, requiring subsequent address decoders, analog-to-digital converters, and image signal processors. They also need three sets of power supply synchronization clock control circuits with different voltages, resulting in very low integration. In contrast, CMOS is integrated onto a single semiconductor material called metal oxide. This process is the same as that used to produce tens of thousands of computer chips and storage devices, making CMOS much cheaper than CCD. Furthermore, CMOS chips can integrate image signal amplifiers, signal readout circuits, A/D conversion circuits, image signal processors, and controllers onto a single chip. A single chip can achieve all the basic functions of a camera, resulting in high integration. This is the origin of the chip-level camera concept. With the continuous development of CMOS imaging technology, more and more companies can provide high-quality CMOS imaging chips, including Micron, CMOSIS, and Cypress.
3. Speed
CCDs use individual photosensitive output, which can only output according to a predetermined program, resulting in slower speeds. CMOS sensors, on the other hand, have multiple charge-to-voltage converters and row/column switch control, leading to much faster readout speeds. Currently, most high-speed cameras with speeds exceeding 500fps are CMOS cameras. Furthermore, CMOS's address gating switches can perform random sampling, enabling sub-window output, which can achieve even higher speeds when only outputting sub-window images.
4. Noise
**CCD technology, having been developed earlier and is relatively mature, employs PN junctions or silicon dioxide (SiO2) isolation layers to isolate noise, giving it a certain advantage in image quality compared to CMOS photoelectric sensors.** **Due to the high integration of CMOS image sensors, with components and circuits closely spaced, interference is significant, and noise greatly impacts image quality.** In recent years, the continuous development of CMOS circuit noise reduction technology has provided favorable conditions for producing high-density, high-quality CMOS image sensors.
What are the main parameters of CCD chips and CMOS chips?
In machine vision, the two main types of photoelectric sensor chips used are CCD chips and CMOS chips. CCD stands for Charge-Coupled Device, and CMOS stands for Complementary Metal-Oxide-Semiconductor Transistor. Both CCD and CMOS chips convert light signals into electrical signals (voltage/current) through the photoelectric effect, storing these signals to obtain an image. The main parameters of CCD and CMOS chips are as follows:
Pixel size
Pixel size refers to the actual physical size of each pixel in a chip's pixel array. Common sizes include 14µm, 10µm, 9µm, 7µm, 6.45µm, and 3.75µm. Pixel size reflects, to some extent, the chip's light response capability; a larger pixel size allows for the reception of more photons and the generation of more charge under the same lighting conditions and exposure time. For low-light imaging, pixel size is a characterization of chip sensitivity.
Sensitivity
Sensitivity is one of the most important parameters of a chip, and it has two physical meanings. One refers to the photoelectric conversion capability of the optical device, the same as responsivity. That is, the chip's sensitivity refers to the output signal voltage (current) per unit exposure within a certain spectral range, and the unit can be nanoampere per lux (nA/Lux), volt per watt (V/W), volt per lux (V/Lux), or volt per lumen (V/lm). The other refers to the radiant power (or illuminance) to ground that the device can sense, the same as detectivity. The unit can be expressed in watts (W) or lux (Lux).
Number of bad pixels
Due to limitations in manufacturing processes, it is almost impossible for all pixels in a sensor with millions of pixels to be good. The number of bad pixels refers to the number of bad pixels (pixels that cannot form an effective image or pixels with inconsistencies exceeding the parameter allowable range) in a chip. The number of bad pixels is an important parameter for measuring chip quality.
Spectral response
Spectral response refers to a chip's ability to respond to light of different wavelengths, and is usually given by a spectral response curve.
How is a line scan camera defined?
Linear scan industrial cameras, as the name suggests, are in the form of "lines." Although they are also two-dimensional images, they are extremely long, several kilobytes in length, while their width is only a few pixels. Generally, this type of camera is only used in two situations:
1. The field of view being measured is a long, narrow strip, which is often used for testing problems on rollers.
2. Requires a very large field of view or extremely high precision.
How to choose a line scan camera?
1. Calculate resolution: Divide the width by the minimum detection precision to get the number of pixels required for each row.
2. Detection accuracy: The actual detection accuracy is obtained by dividing the width by the number of pixels.
3. Number of scan lines: The number of scan lines per second is obtained by dividing the length of the movement speed per second by the precision.
Based on the above calculation results, the following is an example of selecting a line scan camera:
For a camera with a width of 1600 mm, an accuracy of 1 mm, and a movement speed of 22000 mm/s: 1600/1 = 1600 pixels, minimum 2000 pixels, selected as 2K. 1600/2048 = 0.8. Actual accuracy 22000mm/0.8mm = 27.5kHz. The camera should be selected as 2048 pixels at 28kHz.
What are the characteristics of a line scan camera?
1. Line scan cameras typically use line scan sensors with only one row of photosensitive units (a few color line scan cameras use sensors with three rows of photosensitive units).
2. A line scan camera acquires only one line of images at a time;
3. A line scan camera outputs only one line of image at a time;
4. Compared with traditional area scan cameras, area scan captures several rows of images each time and outputs them in frame format.
Why use line scan cameras in machine vision inspection?
1. Line scan cameras have higher resolution; the number of pixels per row in a line scan camera is generally 1024, 2048, 4096, or 8012; while the number of pixels per row in a typical area scan camera is only 640, 768, or 1280, and area scans with more than 2048 pixels are rare.
2. Line scan cameras have a faster acquisition speed; the acquisition speed of different models of line scan cameras ranges from 5,000 to 60,000 lines per second. Users can choose to process an image by combining a few lines or every dozen lines, thus achieving a very high frame rate.
3. Line scan cameras can continuously acquire and process data without interruption; they can continuously acquire data on objects moving in a straight line (linear guide rails, paper on rollers, fabrics, printed materials, objects on conveyor belts, etc.).
4. Line scan cameras have a simpler and more reasonable structure. Compared with area scan cameras, line scan cameras do not waste resolution by acquiring useless data.
What are the differences between line scan cameras and area scan cameras?
Linear CCD industrial cameras are primarily used for image processing in industrial, medical, scientific research, and security fields. In machine vision, line-scan industrial cameras are a special type of vision machine. Compared to area-scan industrial cameras, their sensors have only one row of photosensitive elements, enabling high scanning frequencies and high resolutions. Typical applications of line-scan industrial cameras include the inspection of continuous materials such as metals, plastics, paper, and fibers. The object being inspected typically moves at a constant speed, and one or more industrial cameras are used to continuously scan it line by line to achieve uniform inspection of its entire surface. The images can be processed line by line or as area-scan images composed of multiple rows. Furthermore, line-scan industrial cameras are ideal for measurement applications due to the high resolution of their sensors, capable of measuring accurately down to the micrometer level.
Area CCDs have a wide range of applications, including the measurement of area, shape, size, position, and even temperature. The advantage of area CCDs is their ability to acquire two-dimensional image information, providing intuitive measurement results. The disadvantage is a larger total number of pixels, with fewer pixels per row compared to linear CCDs, limiting the frame rate. Linear CCDs, on the other hand, can accommodate a large number of one-dimensional pixels while maintaining a lower total pixel count compared to area CCD industrial cameras. They also offer more flexible pixel sizes and higher frame rates, making them particularly suitable for measuring one-dimensional dynamic targets.
What image acquisition cards are required for industrial cameras to function properly?
Industrial cameras need to be properly matched with image acquisition cards to function correctly. Generally, the following cards need to be matched:
a. Video signal matching: For black and white analog signal cameras, there are two formats: CCIR and RS170 (EIA). Typically, capture cards support both of these industrial camera formats.
b. Resolution matching: Each board only supports cameras within a certain resolution range;
c. Matching special functions: If you want to use special functions of the camera, first determine whether the card you are using supports the function. For example, if you want multiple cameras to take pictures at the same time, the capture card must support multi-channel. If the camera is progressive scan, then the capture card must support progressive scan.
d. Interface matching: Determine whether the camera and the board's interface are compatible. Examples include CameraLink and Firewire 1394.
What are the differences between industrial cameras with USB interfaces and those with 1394 interfaces?
The main factors influencing our choice between USB cameras and 1394 cameras in terms of interface are as follows:
a) Protocol Specifications: There are over 50 industry-specification protocols related to 1394 devices, covering everything from cameras and industrial cameras. Most manufacturers' 1394 industrial cameras adhere to the DCAM industry standard. The USB interface for industrial cameras, however, is a commercial standard that has recently emerged from commercial PC applications.
b) Power supply: The operating voltage of 1394 industrial cameras is 8 to 30VDC, while the operating voltage of USB industrial cameras is 5VDC. From the perspective of power supply range, the 1394 interface meets the DC power supply requirements of individual devices in the industrial field, such as 12VDC or 24VDC; while the USB interface uses electronic circuit TTL standard voltage power supply and is generally used for internal power supply of devices.
c) Operating system compatibility: 1394 interface industrial cameras can retain their original addresses after a system restart, while USB interface industrial cameras require the system to reassign addresses every time they start up.
d) Data transmission: The 1394 interface has an inherent advantage in handling data transmission between multiple industrial cameras. From a developmental perspective, the USB interface is a new generation of high-speed data transmission interface that succeeds the RS232 interface, while industrial cameras with the 1394 interface were designed as replacements for SCSI and PCI buses.
What is a smart industrial camera?
A smart industrial camera is not simply a camera, but a highly integrated, miniature machine vision system. It integrates image acquisition, processing, and communication functions into a single camera, providing a multifunctional, modular, highly reliable, and easy-to-implement machine vision solution. A smart industrial camera typically consists of an image acquisition unit, an image processing unit, image processing software, and network communication devices. Due to the application of the latest DSP, FPGA, and high-capacity storage technologies, its intelligence level is continuously improving, meeting the diverse application needs of machine vision.
What are the differences between intelligent industrial cameras and general industrial cameras?
In short, the difference between smart cameras and industrial cameras is that a smart camera is a highly integrated, miniature machine vision system, while an industrial camera is a component of a machine vision system.
What are the main functions of the image acquisition unit in a smart industrial camera?
In a smart camera, the image acquisition unit is equivalent to a CCD/CMOS camera and image acquisition card in the conventional sense. It converts optical images into analog/digital images and outputs them to the image processing unit.
What role does the image processing unit play in a smart industrial camera?
In intelligent industrial cameras, the image processing unit is similar to an image acquisition and processing card. It can store image data from the image acquisition unit in real time and perform image processing with the support of image processing software.
What is the main role of image processing software in intelligent industrial cameras?
Image processing software primarily performs image processing functions with the support of the image processing unit hardware environment. These functions include geometric edge extraction, blob generation, grayscale histogram creation, OCV/OVR, simple localization, and searching. In smart cameras, these algorithms are encapsulated into fixed modules that users can directly apply without programming.
What role does the network communication device play in a smart industrial camera?
Network communication devices are an important component of smart cameras, primarily responsible for communicating control information and image data. Smart cameras generally have built-in Ethernet communication devices and support various standard network and bus protocols, enabling multiple smart cameras to form a larger machine vision system.
From what aspects should we compare the different interfaces of industrial cameras?
The following is a comparison of several interfaces for industrial cameras:
What should be considered when choosing an industrial camera?
1. **The choice between CCD and CMOS depends on the application.** CCD industrial cameras are primarily used for image extraction from moving objects, such as in pick-and-place machines. However, with the development of CMOS technology, many pick-and-place machines are also choosing CMOS industrial cameras. CCD industrial cameras are generally more commonly used in vision-based automated inspection solutions or industries. CMOS industrial cameras are becoming increasingly widely used due to their lower cost and lower power consumption.
2. When choosing resolution, first consider the precision of the object to be observed or measured, and select the resolution accordingly. Secondly, consider the output of the industrial camera. For stereoscopic observation or machine software analysis and recognition, high resolution is helpful; for VGA or USB output, observation on a monitor depends on the monitor's resolution. Even if the industrial camera has a high resolution, it's meaningless if the monitor's resolution is insufficient. When using memory cards or taking photos, a high resolution from the industrial camera is also helpful.
3. For lens compatibility, the sensor chip size needs to be smaller than or equal to the lens size, and the C or CS mounting bracket must also be compatible (or an adapter can be added);
4. Camera frame rate selection: When the object being measured requires motion, a high frame rate industrial camera should be selected. However, generally speaking, higher resolution corresponds to a lower frame rate.
How do I configure the "Automatic Gain Control" function in an industrial camera?
Industrial cameras contain a video amplifier that amplifies the signal from the CCD to a usable level. This amplification, or gain, is equivalent to higher sensitivity. However, in bright light, the amplifier will overload, causing video signal distortion. When the switch is ON, the lens aperture is fully opened in low-light conditions, automatically increasing gain to obtain a clear image. When the switch is OFF, a natural, low-noise image is obtained in low light.
What is an image acquisition card?
An image acquisition card, also known as an image processing card, transmits image and video signals from a camera, frame by frame, to the computer's memory and VGA frame buffer for processing, storage, display, and transmission. In machine vision systems, the images acquired by the image acquisition card are used by the processor to determine whether a workpiece is qualified, the amount of motion deviation of moving objects, and the location of defects.
What are the different types of image acquisition cards?
Based on the input signal, image acquisition cards can be divided into analog image acquisition cards and digital image acquisition cards;
Based on the color of the acquired signal, image acquisition cards can be divided into black-and-white image acquisition cards and color image acquisition cards;
How to choose an image acquisition card?
When selecting and using image acquisition cards, two key factors need to be considered: hardware reliability and software support. All other things being equal, a more complex card with more components will dissipate more heat than a card with fewer components. Good designs utilize more ASICs (Application-Specific Integrated Circuits) and programmable devices to reduce the number of electronic components while achieving higher functionality. Cards with fewer unnecessary functions can also be chosen to reduce unnecessary complications. Overvoltage protection is an important indicator of reliability. Proximity to high voltage can generate strong surges in video cables. Adding overvoltage protection circuits to the video input and I/O ports can protect the acquisition card from high voltage breakdown caused by electromagnetic interference in industrial environments. When selecting an acquisition card, it is also essential to consider the compatibility of the vision system software with the acquisition card, its ease of use, and whether the software requires payment.
What are the advantages of high-speed industrial cameras compared to general industrial cameras?
High-speed, real-time, uncompressed image recording with real-time display and set-speed echo;
The system adopts a recording method that directly writes data to the hard drive, solving the problem of short recording time in traditional memory recording methods, and also solving the problems of traditional acquisition methods;
The system's transmission speed is limited by the PCI bus bandwidth.
It guarantees 100% frame-free operation, solving problems such as easy frame loss and lack of power-off protection in traditional memory recording methods;
The system operates independently, consumes almost no computer resources, and has high reliability.
A single system can support multiple boards and cameras, simultaneously tracking and recording multiple targets;
Supports the superposition and fusion of multiple external signals;
Supports multiple image formats and has various software and hardware external triggering functions;
The software interface is simple, making it easy to perform secondary development and real-time processing.
What are the different types of infrared cameras?
Infrared cameras mainly fall into the following categories: near-infrared cameras, short-wave infrared cameras, high-speed infrared cameras, mid-wave infrared cameras, and DSP-based long-wave infrared cameras.
How can the sensitivity of industrial cameras be improved?
The sensitivity of an industrial camera can be adjusted by setting the following functions:
What is white balance in industrial cameras?
White balance is a technique used in color cameras. It balances the red, green, and blue components of the image to ensure the camera accurately reflects the colors of the scene. Because the output of the RGB components of a photosensitive element is unbalanced under different lighting conditions, it can cause color distortion in the image, resulting in a blue or red tint. Therefore, white balance is needed to restore the image's colors. Cameras typically perform white balance in two ways: automatic and manual. Additionally, white balance can also be achieved through software.
How to improve camera light sensitivity uniformity?
How to improve the signal-to-noise ratio of an image?
Signal-to-noise ratio (SNR) reflects a camera's ability to resist interference, which translates to whether the image is clean and free of noise. The following techniques can improve the SNR of an image, making the captured image clearer and cleaner.
How to improve the dynamic range of industrial cameras?
The purpose of camera dynamic range imaging is to accurately represent the wide range of brightness in the real world, from direct sunlight to the darkest shadows. The following techniques can improve the dynamic range of a camera.
How can image quality be improved by adjusting an industrial camera?
In machine vision systems, cameras need to acquire images, but sometimes the quality of the acquired images is not good. This requires us to improve the image quality by adjusting some functional parameters of the industrial camera. The following techniques can improve image quality.
What are the differences between mechanical and electronic shutters in industrial cameras?
Mechanical shutter: Using springs or electromagnetic means, it controls the opening and closing of several blades, or two curtains like a stage curtain "pulling" across the image field window with a certain width of gap, allowing the window to have a "sight of light" for a specified period of time - this is the common concept of mechanical shutter.
Electronic shutter: This type of shutter controls the exposure by directly manipulating the CCD/CMOS sensor through a circuit. It utilizes the principle that the CCD/CMOS sensor is inactive without power. Even though the window is wide open when the CCD is not powered, no image is produced. However, by using an electronic timing circuit to power the CCD/CMOS sensor for a specified duration when the shutter button is pressed, an effect similar to a shutter opening instantaneously can be achieved.
Generally speaking, the advantage of a mechanical shutter is that it can operate without electricity, but the disadvantage is that it is less accurate when comparing high and low shutter speeds. Electronic shutters are more precise, have higher performance (allowing for shorter minimum exposure times, etc.), are more reliable, and have a longer lifespan than purely mechanical shutters.
What are the differences between digital industrial cameras and analog industrial cameras?
Conceptually, the only difference between these two types of cameras is their output signal: analog industrial cameras output analog signals, while digital industrial cameras output digital signals. In other words, the A/D conversion in analog industrial cameras is performed outside the camera itself, while the A/D conversion in digital industrial cameras is completed within the camera itself.
How to maintain industrial cameras?
1. Avoid pointing the camera directly into sunlight as much as possible to prevent damage to the camera's image sensor;
2. Avoid contact between the camera and substances such as oil, steam, water vapor, moisture, and dust; avoid direct contact with water.
3. Do not use harsh cleaning agents or organic solvents to wipe the camera;
4. Do not pull or twist the connecting wires;
5. Do not disassemble the camera yourself or attempt to touch its internal parts unless absolutely necessary, as this can easily damage the camera, and such damage will not be covered under warranty by the dealer.
6. When storing cameras, they should be placed in a clean and dry place.
What is the relationship between resolution and pixels?
Resolution and pixels are directly proportional; the more pixels, the higher the resolution. The higher the pixel count, the higher the maximum output image resolution.
What is the relationship between CCD/CMOS chip size and image size in industrial cameras?
The following table shows the relationship between CCD/CMOS chip size and image size in industrial cameras:
