| I. Introduction of industrial camera type
The CCD was invented by Bell Laboratories in the late 60. Started as a new kind of PC storage circuit, soon CCD has many other potential applications, including signal and image (silicon photosensitivity) processing.
CCD is a thin silicon wafer processing a series of different functions, on each silicon wafer on the distribution of several identical IC, such as the production of functional components, the selected IC from the silicon wafer cut off packaging in the carrier used in the system. In summary, the CCD mainly has the following types:
1, Surface array CCD industrial camera:
Allows the photographer to shoot moving objects at any shutter speed under one exposure.
2, line array CCD industrial camera:
Scan images with a row of pixels, do three exposures--Yu Hong, green, and blue filters, as the name indicates, linear sensors capture one-dimensional images. Initially used in the advertising community to capture static images, linear arrays, when processing high-resolution images, subject to the non-moving continuous illumination of the object.
3, three-wire sensor CCD industrial camera:
In a three-wire sensor, three rows of parallel pixels cover the RGB filter, and when the color picture is captured, the full color picture is composed of multiple rows of pixels. Three-wire CCD sensors are used in high-end digital cameras to produce high resolution and spectral levels.
4. Interlaced Transmission CCD industrial camera:
This sensor uses a separate array to ingest images and power conversions, allowing the current image to be read when the next image is taken. Interlaced transmission CCD is typically used for low-end digital cameras, camcorders, and video-capturing machines for shooting animations.
5, full-format CCD industrial camera:
The CCD has more power handling capability, better dynamic range, low noise and transmission optical resolution, and full-format CCD allows instant capture of full-color images. The full-format CCD consists of a parallel floating-point register, a serial floating-point register, and a signal output amplifier. Full-format CCD exposure is controlled by a mechanical shutter or gate to preserve the image, and parallel registers are used for metering and reading metering values. The image is projected onto a parallel array as a projection screen. The component receives the image information and divides it into discrete elements that are quantified by the number. These streams are streamed from parallel registers to serial registers. This process is performed repeatedly until all the information is transferred. Then, the system carries out the accurate image reorganization.
Ii. introduction of industrial camera parameters
Industrial camera is a key component in machine vision system, its most essential function is to transform the light signal into an orderly electrical signals. Choosing the right camera is also an important part in the design of machine vision system, the camera not only directly determines the image resolution and image quality, but also is directly related to the operation mode of the whole system.
Main Parameters
1. Resolution (Resolution): Every time the camera captures the image pixel points (Pixels), for the digital industrial camera machine is generally directly related to the number of photoelectric sensors, for the analog camera machine is based on the video format, PAL system for the 768*576,NTSC system for the 640* 480.
2. Pixel depth (Pixel Depth): That is, the number of bits per pixel data, commonly used is 8Bit, for the digital industrial camera machine will generally have 10Bit, 12Bit and so on.
3. Maximum frame rate/row frequency (line rates): The rate at which the camera machine captures the transmitted image, the number of frames per second (frames/sec.) for the plane array camera, and the number of lines (HZ) that the line array camera is collecting per second.
4. Exposure mode (Exposure) and shutter speed (Shutter): For line array camera is a progressive exposure mode, you can choose the fixed line frequency and external trigger synchronization of the acquisition mode, the exposure time can be consistent with the line period, you can also set a fixed time; industrial cameras have frame exposure, field exposure and rolling line exposure, and other common methods, digital industrial camera machine generally provide external trigger mining diagram function. Shutter speeds are typically up to 10 microseconds, and high-speed industrial cameras can be faster.
5. Cell size (Pixel size): The cell size and number of cells (resolution) together determine the size of the camera's target surface. At present, digital industrial camera cell size is generally 3μm-10μm, the smaller the general cell size, the greater the difficulty of manufacturing, the image quality is not easy to improve.
6. Spectral response characteristics (spectral range): refers to the cell sensor sensitivity to different light waves, the general response range is 350nm-1000nm, some camera machine in front of the target with a filter, filter out the infrared light, if the system needs to be sensitive to the infrared can be removed from the filter. |
