Advantages of line scan cameras, how to choose line scan cameras and lenses

The linear CCD image acquisition scheme has its own unique advantages in the following aspects:

1. The cost of linear array CCD plus scanning mechanism and position feedback link is still much lower than that of area array CCD with the same area and resolution;

2. The coordinates of the scanning line are provided by the grating, and the indication accuracy of the high-precision grating ruler can be higher than the manufacturing accuracy of the area array CCD pixel spacing, in this sense, the accuracy of the image obtained by the linear array CCD in the scanning direction can be higher than that of the area array CCD image;

3. The latest linear array CCD sub-pixel splicing technology can dislocate 1 2 pixels in the direction of the length of the pixel ** array of two CCD chips by optical methods, which is equivalent to inserting all the pixels of the second CCD into the pixel gap of the first CCD in turn, indirectly "reducing" the size of the linear array CCD pixels, improving the resolution of the CCD, and alleviating the problem that it is difficult to reduce the size of the CCD pixels due to the influence of technology and materials. Theoretically, higher resolution and accuracy can be obtained than area array CCD.

Line scan industrial cameras, as the name suggests, are in the shape of a "line" imaging sensor. Although it is also a two-dimensional image, it is extremely wide, a width of several thousand pixels, and the height is only a few pixels. This camera is generally used in two situations:

1.The field of view to be measured is a slender ribbon, which is mostly used for detection problems on the drum.

2.Requires a great field of view or extreme precision.

Features of line scan cameras:

1.Line scan cameras typically use line scan sensors with only one line of sensors (a few color line scans use two or three lines of sensors).

2.The line scan camera captures only one line of images at a time.

3.The line scan camera outputs only one line of images at a time.

4.In contrast to traditional area scan cameras, area scan captures several lines of images at a time and outputs them in frames.

Why use line scan cameras in machine vision inspection?

1.Line scan cameras have higher resolutions. Line scan cameras generally have pixels per line, and 16384 is also common; However, the general area scan camera is only , and area scans larger than 4096 are rare.

2.Line scan cameras have faster acquisition speeds. The acquisition speed of different models of line scan cameras ranges from 8,000 to 180,000 lines per second, and users can choose to form a frame of image every few lines or every dozen lines for processing, so that high frame rates can be achieved.

3.Line scan cameras enable uninterrupted and unrepeated, continuous acquisition and processing. Line scan cameras can continuously capture objects moving in a straight line (linear guides, paper, fabrics, prints, objects on conveyor belts, etc.).

4.Line scan cameras have a simpler and more rational structure. In contrast to area scan cameras, line scan cameras do not waste resolution to acquire useless data.

Welcome to the machine vision product information query platform.

Calculate the resolution: Divide the width by the minimum detection accuracy to get the number of pixels required for each row of the selected camera: Divide the width by the number of pixels to get the actual detection accuracy.

The length of the movement speed per second divided by the accuracy gives the number of rows scanned per second.

Select a camera based on the above values.

Lens: sensor length (pixel width, number of pixels) ?Object distance? Width such as width 1600 mm, accuracy 1 mm, movement speed 22000mm s camera: 1600 1 1600 pixels.

Minimum 2000 pixels, selected as a 2K camera.

1600 2048 Actual accuracy.

22000mm/

Should the camera be selected as 2048 pixels? 28kHz camera.

In the field of machine vision, line scan industrial cameras are a special type of vision machines.

In contrast to area scan industrial cameras, its sensor has only one line of light-sensitive elements, thus enabling high scanning frequencies and high resolution. A typical area of application for linear industrial cameras is the detection of continuous materials such as metals, plastics, paper, and fibers. The object to be inspected usually moves at a uniform speed, and one or more industrial cameras are used to continuously scan it line by line to achieve uniform detection of its entire surface, and the image can be processed line by line, or the area array image composed of multiple lines can be processed.

In addition, line scan industrial cameras are ideally suited for measurement applications thanks to the high resolution of the sensors.

For area scan cameras, there are a wide range of applications, such as area, shape, size, position, and even temperature measurement. The advantage of area scan cameras is that they can acquire two-dimensional image information and measure images intuitively. The disadvantage is that the total number of pixels is large, and the number of pixels per line is generally less than that of the line array, and the frame speed is limited, while the advantage of the line scan camera is that the number of one-dimensional pixels can be done a lot, and the total number of pixels is less than that of the area array industrial camera, and the pixel size is more flexible, and the number of image frames is high, which is especially suitable for the measurement of one-dimensional dynamic targets.

Welcome to the machine vision product information query platform.

First, the reference is different.

1. Line scan camera: in the shape of a "line". Although it is also a two-dimensional large image, it is extremely long. It's a few kilometres in length, but it's only a few pixels in width.

2. Area scan camera: the pixel matrix shooting is realized.

Second, the characteristics are different.

1. Line scan camera: the measured field of view is a slender ribbon, which is mostly used for detection on the drum. Requires a great field of view or extreme precision.

2. Area scan camera: The performance of image details is not determined by the number of pixels, but by the resolution. The resolution is determined by the focal length of the selected lens, and the resolution of the same camera is different when the lens with different focal length is selected.

Third, the application is different.

1. Line scan camera: mainly used in image processing in the fields of industry, medical treatment, scientific research and security. Typical areas of application are the inspection of continuous materials such as metal grips, plastics, paper, and fibers.

2. Area scan camera: It has a wide range of applications, such as the measurement of area, shape, size, position, and even temperature.

Line scan cameras and area scan cameras are two commonly used industrial cameras, and they have some differences in working principle, applicable scenarios and application characteristics.

1.How it works:

Line scan camera: Acquires image data from objects line by line with a one-dimensional line scan sensor. Since it can only be collected one acre at a time, it is necessary for the object to move linearly within the camera's field of view to obtain an image of the entire object.

Area scan camera: The entire image data is collected simultaneously by means of a 2D area scan sensor. Objects that are still or in motion can be captured directly.

2.Applicable Scenarios:

Area scan camera: It is suitable for image acquisition of stationary or slow-moving objects, such as product inspection, robot vision, security monitoring, etc.

3.Resolution:

Line Scan Camera: Since it can only be collected on a line-by-line basis, its resolution is determined by the number of pixels on the sensor and the number of lines collected per second. Usually has a high resolution and a high pixel density.

Area scan camera: The entire image can be captured directly, and the resolution is determined by the number of pixels on the sensor. It can be available with different resolutions and pixel densities to suit different application needs.

4.Dynamic Range:

Line Scan Cameras: High dynamic range is available due to progressive acquisition, making it suitable for applications where lighting conditions are critical.

Area scan cameras: Due to the simultaneous acquisition of the entire image, the dynamic range is narrow, and the requirements for lighting conditions are low.

It should be noted that the area scan camera can simulate the function of the line scan camera by software means, that is, the image processing algorithm is used to stitch multiple area array images, so as to realize the image acquisition of moving objects. Instead, this approach often requires higher computing resources.

Consider the following scenario, where the target is a length of cloth that is constantly in length (which can be thought of as infinity) and has a long width, and it is not possible to shoot with an area scan camera.

There are three solutions at this point.

Defect detection of golf balls.

Let's start with the lenses of area scan cameras.

Now expand the camera to 4 times wide, as shown below.

Because the line scan camera only shoots one line at a time, the light source is generally formedLong strips, no need to make a noise to be too big, the banquet can save costs.

High power, high brightness, high uniformity

High brightness: liquid Xiang wide.

Area scan camera 60fps, **time 1 60s per frame.

Line scan camera 61440 lines per second, **time 1 61440, per frame, about 1000 times worse.

The line scan camera** is two or three times that of the general area scan camera, and the light source of the line scan camera sometimes costs about 6,000 yuan. The following is a screenshot of the light source information of a certain brand of line scan camera.

Industrial area scan cameras and line scan cameras are two common types of machine vision cameras, and they have some differences in their working principles and applications.

1.How it works: An industrial area scan camera consists of a two-dimensional pixel array that can simultaneously acquire height and width information of an image.

Each pixel independently captures the light signal and converts it into a digital image. Line scan cameras, on the other hand, consist of only one line of pixels, and the image information is acquired line by line along the direction of the scan.

2.Applications: Industrial area scan cameras are suitable for applications that need to capture images of entire objects or fields, such as product inspection, quality control, machine vision, etc.

They can acquire high-resolution images of Tongmin in real time, which is suitable for static or fast-moving scenes. Line scan cameras are suitable for applications that need to capture high-speed motion or continuous flow of objects, such as high-speed shooting, barcode scanning, text recognition, and more. Line scan cameras capture images by continuously scanning at high speeds, which can achieve higher frame rates.

3.Resolution and speed: Industrial area scan cameras typically have a high resolution and are capable of delivering detailed images. Line scan cameras have a relatively low resolution but are capable of capturing images at very high speeds.

4.Cost: Industrial area scan cameras are typically more expensive than line scan cameras because they require more pixels and processing power to acquire panoramic images. Line scan cameras are relatively inexpensive and are suitable for high-speed applications where resolution is not a high priority.

In summary, industrial area scan cameras are suitable for applications that require high-resolution, panoramic images, and line scan cameras are suitable for high-speed motion or continuous flow applications. The choice depends on application needs and budget constraints.

In machine vision inspection, line scan industrial cameras offer several advantages that make them suitable for this application:

1.High-speed capture capability: The line scan industrial camera captures images in a series of continuous** ways, and can collect images at a non-terrestrial high speed, which is suitable for scenarios that need to be detected on high-speed moving objects.

2.High resolution: The pixel arrangement of line scan industrial cameras is line by row, and due to the special nature of the camera sensor arrangement, it can provide very high line resolution, which makes line scan cameras have advantages in image detail display and fine measurement.

3.Anti-shake early grip ability: Since the line scan camera captures a continuous line of images during the capture process, it can reduce the image blur caused by the handheld camera or object movement and ensure the image quality.

4.Suitable for long object detection: Due to the special way of collecting images by line scan cameras, line scan cameras are more suitable for the detection and measurement of long objects than area scan cameras, and can capture continuous images of the entire long object.

In summary, line scan industrial cameras can provide advantages such as high speed, high resolution, and anti-jitter in machine vision inspection, and are suitable for applications that require high-speed capture and fine measurement.

In machine vision inspection, line scan industrial cameras are suitable for machine vision inspection due to the following advantages:

High-speed acquisition: The linear scan industrial camera adopts the method of progressive scanning, which can achieve high-speed image acquisition, which is suitable for rapid detection of moving objects.

High resolution: The line scan industrial camera can achieve high-resolution image acquisition, which can capture more detailed image information and improve the accuracy of detection.

High sensitivity: The pixel arrangement of line scan industrial cameras can improve the sensitivity of the camera, and for scenes with low brightness, it is still possible to obtain clear and clear images in the morning.

Long-term stability: The line scan industrial camera has good qualitative and durability, can work stably for a long time, and is suitable for industrial application environments.

Easy integration: Line scan industrial cameras can be quickly integrated with other devices through standard interfaces (such as Gige Vision, Camera Link, etc.), which is convenient for system construction and application development.

In summary, line scan industrial cameras have many advantages in machine vision inspection, which can improve the speed, accuracy and stability of inspection, so they are suitable for machine vision inspection.

Typical areas of application for line scan cameras are the detection of continuous materials such as metals, plastics, paper, and fibers. The object to be inspected is usually moving at a constant speed, and one or more cameras are continuously scanned line by line to achieve a uniform inspection of its entire surface. The image can be processed line by line, or by area array image consisting of multiple lines.

In addition, the line scan camera is ideal for measurement occasions, thanks to the high resolution of the sensor, which can accurately measure down to the micron.

1. Line scan camera, as the name suggests, is in the shape of a "line". Although it is also a two-dimensional image, it is extremely long, a few kilometres in length, and only a few pixels in width. In general, this camera is used in only two situations:

1. The field of view to be measured is a slender ribbon, which is mostly used for detection on the drum. Second, it requires a great field of view or extremely high precision.

2. In the second case (which requires a large field of view or extremely high precision), it is necessary to excite the camera many times with an excitation device, take multiple pictures, and then merge the multiple "strip" images taken into one huge picture. Therefore, with a line array camera, it is necessary to use a frame grabber that can support line array cameras. The image of the general camera is 400k 1m, and the combined image is several m so large, and the speed is naturally slow.