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CCD color camera the main technical indicators

    

1. CCD size, that is, camera target surface. More than the original 1 / 2 inches, 1 / 3 inches has been the popularity of the 1 / 4 inches and 1 / 5 inches has commercialization.
2. CCD pixels, the CCD is the main performance indicator, it decided to show the clarity of the image, the higher the resolution, the better the performance of image detail. By the CCD array of sensitive elements, each element known as pixels, the more pixels, the images more clear. Most of the market now to 250,000 and 380,000 pixels for the demarcation, more than 380,000 pixels for high-definition video camera.
3. Horizontal resolution. The typical resolution color video camera in the 320 to 500 TV lines between the main line 330, 380 lines, 420 lines, 460 lines, 500 lines, and different grades. Resolution is the electricity line of sight (of TV LINES) to express the color camera in the resolution of between 330 to 500 lines. And the resolution of the CCD and the lens, with the camera circuit channel bandwidth is directly related to the law is usually 1 MHz bandwidth equivalent to 80 lines for clarity. The broader the bandwidth, the more clear image, the greater the relative value line.
4. Minimum illumination, also known as sensitivity. CCD light on the environment is the degree of sensitivity, or a CCD imaging by the normal needs of the most dark light. Illumination units are Döllekes (LUX), the smaller the value, expressed the need for the less light, camera and the more sensitive. Moonlight and Stars-class high-level sensitization of the camera can work in a very dark conditions,
1 ~ 3lux general illumination
Moonlight type: normal work intensity around 0.1 LUX
Star type: normal illumination required for the following 0.01 LUX
Infrared-used infrared lighting, in the absence of light can also be the case imaging (black)
5. Scan format. NTSC and PAL system with a points system. China used interlaced scanning (PAL) standard (black for the CCIR), the standard for the 625 line, 50, the only medical or other professional fields to use some non-standard format. In addition, Japan is NTSC format, the 525 line, 60 field (black for the EIA).
6. Camera power. Exchange of 220 V, 110V, 24V, DC for 12 V or 9 V.
7. SNR. The typical value of 46 db, if for 50 db, while a small amount of image noise, but the image quality is good if it is 60 db, image quality is excellent, there is no noise.
8. Video output. For more than 1 Vp-p, 75 ¦¸, BNC connectors are used.
9. Lens installed. C and a CS, two different, because different photographic distance.
10. CCD camera color of adjustable features
(1) synchronous mode of choice
A, the single camera, the main way synchronization with the following three:
In sync - the use of cameras within a crystal oscillator circuit synchronization signal to finish.
In sync - the use of a synchronous signal generator, the synchronization signal to the camera, synchronization input to achieve synchronization.
Power Sync - also known as linear lock or lock line is the use of cameras to complete the exchange of power to promote vertical sync, camera and power lines, simultaneously.
B, the multi-camera system, hoping that all the video input signal is vertical synchronization, such transformation in the camera output, will not cause the screen distortion, but due to many camera systems in the camera for Taiwan CLP may be taken from the three-phase power in different phase, or even the whole system is not synchronous with the AC power, the measures could be taken at this time are:
Are used simultaneously with a signal generator outside the synchronized signal into the camera, the Taiwan sync input to adjust simultaneously.
Adjust the camera Taiwan's "adjustment phase" potential, because of cameras at the factory, its vertical sync with the rising edge of the AC is a 0.1-phase, it will enable the use of each phase delay circuit camera Have different phase shift to obtain the appropriate vertical synchronization, phase adjustment range from 0 to 360 degrees.
(2) AGC
All cameras will have a signal from the CCD can be used to enlarge the standard of the video amplifier, which put a lot of gain, equivalent to a higher degree of sensitivity, so that it can in the dim light of the sensitive, but in the bright light Amplifiers environment will be overloaded, so that the video signal distortion. To this end, the camera need to take advantage of the automatic gain control (AGC) circuit to detect video signal level, timely switch AGC, so that cameras can be light in the larger scope of work, that is, dynamic range, that is, Minimum illumination at the camera automatically increases the sensitivity, thereby enhancing the image signal strength to get a clear image.
(3) Background light compensation
Usually, the camera work is AGC through the entire field of view for the contents to determine the average, but if the field of view includes a very bright background of a very dark area and the prospect of goals, work at this time determine the AGC Point has the potential for future goal is not appropriate, background light compensation may improve the prospects of the situation shows that goal.
When the background light compensation for the Open, the only camera the entire field of view of a sub-regional average for AGC to determine its work, at this time if the target prospects in the sub-region, the prospects of the target is expected to improve visibility .
(4) electronic shutter
In CCD camera, is electronically controlled using optical imaging of the surface charge accumulation time to manipulate the shutter. E-CCD camera shutter control the cumulative time, when the electronic shutter closed, the NTSC video camera, the CCD cumulative time of 1 / 60 seconds for PAL video camera, and 1 / 50 seconds. When the electronic camera shutter opens, the NTSC video camera, electronic shutter step coverage from 261 to 1 / 60 second to 1 / 10000 seconds of the scope of the PAL-camera, while its electronic shutter 311 Step Coverage from 1 / 50 second to 1 / 10000 second range. When the electronic shutter speed increases, in each video field within the time allowed, in focusing on the CCD-reduction, the result will be to reduce the sensitivity of the camera, however, the higher the shutter speed to observe the motion picture will have a "standstill Action "effect, this will greatly increase the dynamic camera resolution.
(5) White Balance
White Balance used only for color video camera, video camera to achieve its purpose is to accurately reflect the image features situation, a manual white balance and automatic white balance in two ways.
A, Auto White Balance
Continuous mode - this time with features white balance settings will change the color temperature of continuous adjustment in the range of 2800 ~ 6000 K. This way the color temperature of the scene during the filming of the changing occasion is the most appropriate so that the natural color performance, but the scene in little or no white, for the duration of color can not produce the best results.
Button way - first at the camera, such as Bai Qiang, White and other white target, and then automatically switch to manually transferred from the set position, remain in the position to a few seconds or white image showed up in white Balance is executed, it will automatically switch back to be manually locked position to the white balance settings, white balance settings at this time will remain in the memory of the camera, again until the implementation date be changed, the range of 2300 ~ 10000 K During this period, even if the camera has not lost the power settings. White Balance mode button to set the most accurate and reliable, applicable to most applications.
B, manual white balance
A manual white balance will turn off the automatic white balance, then change the image of a red or blue state of as many as 107 grades for the regulation, such as the increase or decrease in the red of a class, increase or decrease the blue one level. In addition to the outside, some still camera white balance will be fixed in 3200 K (incandescent level) and 5500 K (daylight level), and other grades of order.
(6) color adjustments
For most applications, the camera is no need to make color adjustments, adjustments would need careful adjustment so as not to affect other colors, adjustable color ways:
Red - yellow color to increase, then the red to magenta mobile step.
Red - to reduce the yellow color, red to yellow at this time will move step.
Blue - yellow color to increase, this will be blue to blue green movement step.
Blue - yellow color reduction, at this time will be blue to magenta mobile step.
3, digital-control method of adjustment
New video camera on the aforementioned optional parameters of the adjustment based on digital adjustment control, then having to manually adjust potentiometer but by supporting control codes, and the adjustment of parameters to be stored in digital memory unit, an increase of stability And reliability.
DSP camera DSP term in the CCTV industry is increasingly widely used. DSP in the analog format on the basis of the introduction of the digital processing technology, called digital signal processing (DSP, DIGITAL SIGNAL PROCESSO
(Digital Signal Processing) is the acronym for digital signal processing. DSP chips raise the camera and video processing performance. DSP technology is not only so that the camera was on the edge in performance, but also to save the parts manufacturers and assembly time, thereby reducing costs. DSP cameras can be divided into two categories: 1, intelligent camera DSP
Such cameras at the same time improve the image of a smart performance characteristics. A typical smart camera has the following characteristics.
a. programmable background light compensation
b. video dynamic testing
c. through the serial data interfaces for remote control
d. built-in character generator
e. 2-screen menu, general-DSP camera
Such a low level of the DSP and DSP cameras do not have any intelligence-related characteristics, is only for lower cost considerations. The kind of camera has the following advantages:
1, the use of digital computing and digital detection technology with intelligent background light compensation. Conventional cameras perturbation features request to be placed in the central screen and to occupy a larger area can have a better background light compensation, or a bright background light may reduce the transparency of image center. DSP cameras and a screen is divided into 48 small to effectively address regional testing goals, even if this is a very small, thin or not to screen the central region of scenery can clearly presented.
2, the DSP technology to automatically tracking white balance, that is, in any condition to detect and track the "white" and digital processing function to reproduce the original colors. The traditional camera because of all the colors on the screen for handling an average, so if the color objects on the screen occupy large area, then color will return imbalance, which is not reproduce the original colors. DSP camera is a screen divided into 48 small to deal with regional, and this can effectively detect and white, even if only a very small screen on a piece of white, the camera can track it and to show the original colors. In the grid-like object shooting, the camera can be caused by noise color image-aliasing reduced to a minimum.
Minimum illumination of a correct understanding that the camera illumination » Illumination (LUX) to the number of numerical for Minimum illumination » How much value to adapt to the surrounding environment intake images »
     Illumination brightness for a unit, as its name suggests, refers to the uptake video cameras, lighting brightness of the surrounding environment of demand, 1 LUX approximately equivalent to a candlelight vigil in the 1-meter distance illumination, we camera parameters in the specifications of the most common Minimum illumination (MINIMUM. ILLUMINATION), said that the camera simply marked by the LUX value, that is, to obtain a clear video screen, the smaller the better value, the higher the sensitivity of the CCD note. Under the same conditions, black-and-white video camera for illumination need to be dealt with than the color of the color camera to the low 10 times.
     General: Summer sun to 100,000 LUX; cloudy day outdoors for 10000 LUX; indoor fluorescent lamps for 100 LUX; from 60 W lamp 60 CM desktop for 300 LUX; television studio for the 1000 LUX; indoor evening for the 10 LUX; night lights for 0.1 LUX; candlelight (20CM distant) 10 ~ 15 LUX.
     Advertised on the market today is whether the Minimum illumination camera manufacturers or importers, the definition of Minimum illumination divergent conflicting, color video camera from 0.0004 LUX ~ 1LUX, black and white video camera from 0.0003 ~ 0.1 LUX have, (if with infra-red, are Up 0 LUX), this is the domestic market in the CCTV industry the technical specifications there was no uniform standards, and have all said that if all the circumstances.
Ultra-dynamic (super dynamic) is the actual dynamic wide. Panasonic and other companies in cp450/cp650/bp550 third-generation cameras are used in the technology, can effectively expand ccd photographic imaging, dynamic range, improve the camera than 40 times, in a sense, super-dynamic Compensation is backlit technology upgrades.
    Ultra-dynamic use of technology is the core of a new two-speed ccd image sensors, to the scene at the same time for different lengths of time exposure, that is to read out the standard shutter speed and signal transmission standards, and faster shutter speed to read And to transmit high-brightness signal. Then the length of time exposed the signal for the image processing integrated circuits (mn67352) in a signal separation and time period of transformation and appropriate, and then raised by the appropriate correction, conversion of touch, output expanded 40 times the dynamic range of images .
    Then the further improvement of 460 ultra-dynamic technology, this is the second-generation ultra-dynamic (super dynamic2) technology, that is, we commonly known as the ultra-dynamic, his dynamic range than the average 80 times higher than
    Second-generation super-dynamic still use the two-speed ccd image sensor and a digital signal processing technology, Time (1 / 50 s) will enable the backlight on the screen in the main image clearly visible, short-term exposure (1 / 2000 -1/4000s) Will enable on-screen glare of the structured home without excessive exposure, and then through enhanced digital processing technology will be two screen images of better quality to be part of that can be fully clear the screen .
     Second-generation super-dynamic has also adopted an independent agc inflection point circuits and digital circuits (knee circuit). Used two second-generation super-dynamic agc circuit, independent of the long time exposure signals and signals a short period of time were exposed to the best of treatment and to avoid s / n lower than the problem. As the two groups have different agc circuit from the control point, the camera output in the curve of the two appeared on the inflection point.
     Second-generation super-dynamic may also increase the literacy level of the gray level, namely: the black level reference to the use of class-correction circuit, and to allow the low-level motor can be adjusted gain value, use the correct black level reference images can More stable, that is, images of the black part of the show will be black.
     Second-generation super-dynamic also adopted an advanced digital noise reduction (dnr) circuit, gain adjustment and digital circuit 2 r filter, the sensitivity can be ccd upgrade 12 db (of which 7 db provided by the dnr circuit), so that the Minimum illumination to improve to 08 lux. Compared to the general camera 3-100 lux and dynamic generation of ultra-3-3000 lux of illumination of the second generation reached 0.8-10000 lux
CCD camera of Reference
     Most cameras on the market is used in Japan SONY, SHARP, Panasonic, LG and other companies producing the chips, now South Korea also have the capacity to produce, but the quality will low a little bit. Because chips produced by the different levels of production, the factory was way different reasons, the CCD acquisition also very different results. At the time of purchase, you can take the following method of detection: Access to power, video cables to connect monitors to close the lens aperture, the black image to see whether there are bright spots, a little snow on the screen, the CCD chip testing is the most simple and direct Methods, and does not require other special equipment. You can then open the aperture to see a still life, if a color camera, the best intake of a colorful object to view the images on the monitor whether the color cast, distorted, or gray color is smooth. Good CCD can restore the good features of the color, make it clear natural objects; Canci for the image there will be color cast phenomenon, even in the face of a White, the image will also be displayed blue or red. Individual production workshop of the CCD due to dust, CCD will be the target surface impurities, in normal circumstances, the impurities will not affect the image, but in poor light or microscope camera, a tiny dust may cause adverse consequences, if used Such work must be carefully selected.
                        Lens choice and the main parameters
Video surveillance camera lens system is the most critical equipment, and its quality (indicators) directly affect the quality of the camera indicators, therefore, the choice of camera lens whether it is appropriate not only related to the quality of systems, and related to construction cost.
The lens of the human eye lens, lens If not, people saw no object, if there is no lens, the camera output by Bai Mangmang image is the one, no clear image output, which is our home video camera and the camera Principle is the same. When the muscles of the human eye lens can not stretch to normal position, it is often said of myopia, the immediate landscape has become blurred; camera lens and the co-ordination and a similar phenomenon, when the image is not clear , The camera can adjust the focus after the change CCD chip and the distance between the lens base level (equivalent to adjust the location of the human eye lens), can become blurred image clarity. Thus, in the closed-circuit camera monitoring system in the role is very important. Engineering design and construction personnel often have to deal with the lens: according to the designers of distance, image size calculated focal length of the lens, the construction of regular on-site commissioning, part of which is to adjust the lens to the best condition.
1, Lens classification
Appearance at the function by the aperture size of the sub-type by the zoom focal length of the Long Range
Spherical Lens 1 "25mm automatic diaphragm electrical long focal length zoom lens
Aspheric lens 1 / 2 "3mm manual aperture standard zoom lens manually
Pinhole Lens 1 / 3 "8.5mm fixed-aperture fixed wide-angle lens focal length
Fish glasses the first 2 / 3 "17mm
(1) to install the camera Category: All the camera lens is threaded the mouth, CCD camera lens installed in two industry-standard, that is installed at C Block and the installation of CS. Thread part of the two is the same as from the camera to the distance between different photosensitive surface. Block C installation: from the camera installed base-level focus to the distance of 17.526 mm. CS installed at: C special installation, at the front of the cameras should be removed to install the camera washers. Its installed base-level lens to focus the distance is 12.5 mm. If you want to install a C-Block to install a camera on the Block, CS installed, you need to use the lens converters.
(2) camera lens specifications Category: camera lens specifications of the CCD camera should be depending on size may be, the two should be relative. CCD camera that is the target size of 1 / 2 inches, should be elected Lens 1 / 2 inches. The CCD camera the size of the target for 1 / 3 inches, should be elected Lens 1 / 3 inches. The CCD camera the size of the target of 1 / 4 inches, should be elected Lens 1 / 4 inches. If the CCD camera lens size and the size of the target of inconsistency, the observation point of view would be inconsistent with the design requirements, or a screen outside the focus of such issues.
(3) lens aperture Category: a manual lens aperture (manual iris) and automatic aperture (auto iris) of the points, with the use of cameras, manual aperture lens suitable for the brightness of the same applications, automatic lens aperture for Brightness changes its aperture also be automatically adjusted, the brightness changes to the occasion. Auto aperture lenses are of two kinds: one which will be a video signal and power transmission from the camera lens to control the lens aperture, known as video input type, the other which use the camera to direct control of DC voltage Aperture, known as the DC input type. Auto aperture lens on the ALC (automatic-control) adjusted for the set metering system, the average brightness of the screen, can also screen some of the brightest (peak) to set the benchmark signal strength, the supply of automatic use of aperture adjustments. In general, ALC has been set at the factory after, may be adjusted, but the shooting scene contains a very high brightness of the target, the target of the bright image may be caused by "white-level clipping" phenomenon and Makes all the screen into a white, ALC at this time can be adjusted to transform the screen. In addition, the lens aperture equipped with automatic aperture ring, rotating aperture ring, through the lens of flux will change and flux that is aperture, the general said with F, its value for the focal length of the lens and lens-of-calibre than that: F = f (focal length) / D (Lens practical and effective diameter), F value of the smaller, the greater the aperture. Automatic use of the lens aperture, for the following application is the ideal choice, they are: such as direct sunlight, and so very bright circumstances, with automatic lens aperture can have a wide dynamic range. In the entire field of vision demands a good focus, with automatic lens aperture is greater than the fixed-aperture lens depth of field. In light on the requirements for optical signal caused by the fuzzy hours, the use of automatic aperture lens.
(4) to the field of view lens size Category: standard lens: 30-degree angle about 1 / 2 inch CCD camera, standard focal length of the lens set at 12 mm, in 1 / 3 inch CCD camera, standard lens As a focal length of 8 mm. Wide-angle: 90 degrees above perspective, the focus can be less than a few millimetres, may provide a more broad visual. Telephoto lens: less than 20 degree angle, the focal length of up to a few meters or even tens of meters, the long-distance lens in the circumstances of the shooting will affect Larger objects, but the observation of the minor. Variable power lens (zoom lens): Also known as telescopic lens, a variable power hand lens and lens two types of electric variable power. Variable focus lens (vari-focus lens): It ranged from standard lens and between the wide-angle lens, the focal length of continuous variable, remote objects can be enlarged, at the same time provide a broad vision, so that surveillance of the increase. Zoom lens can be set up automatic focus on the minimum and maximum focal length of the focal length of two locations, but from the smallest to the largest focal length between the focal length of the focus, manual focus is required to achieve. Pinhole camera: the lens a few millimetres in diameter, can be concealed installation.
(5) from the camera focus on the short focal length lens: a result of a wide angle, can provide a more broad perspective. In focal length lens: standard lens, the focal length depending on the length and size of the CCD. Long focal length lens: a result of a narrow angle, it can only provide a narrow view of, applicable to long-range surveillance. zoom lens: usually electric, for wide-angle, standard or Yuanwang, such as the use of the camera.
  1) will focus: fixed focal length, aperture and there can be divided into two non-aperture.
     • have aperture: lens aperture size can be adjusted. According to the environmental light changes, the corresponding adjustment of the aperture size. Aperture size can be adjusted automatically or manually. Man-made manual adjustments aperture, known as the manual aperture; micro-motor carrying the camera automatically adjusts the aperture, known as automatic diaphragm.
     • No aperture: that is, the aperture, the amount of light-is fixed. Main source or a constant camera comes with electronic shutter situation.
     2) Zoom: the focal length can be adjusted as needed, so that was the object image perturbation zoom in or out.
     Zoom commonly used for six times, 10 times zoom.
     Three variable lens: adjustable focal length, for focusing, for aperture.
     The variable lens: adjustable focal length, for focusing, automatic diaphragm.
        Notes:
     Zoom lens - the location of a fixed focal plane, and Coke Road continuous adjustment of the optical system. Zoom lens is mobile within the lens, change the relative position between them and to realize. This can be changed within a certain scope and length of the lens focal length perspective.
     Focal length - Lens centre or second plane to the main image gathering point distance. Units generally mm or inches.
     Aperture - in some of the camera lens, you can adjust the optical mechanical Lang also can be used to control the light through the lens of how many.
     Auto aperture - the divide-camera device, according to television video signals transmitted from the camera to adjust itself to adapt to changes in light intensity. Aperture divide through open or close the aperture to control the transmission of light through the lens. Typical of the scope of compensation is 10000-1 to 300000-1.
2, select the technical basis for the camera
(1) Lens size of the imaging CCD camera should be in line with the target surface size, as mentioned earlier, a 1-inch, 2 / 3 inches, 1 / 2 inches, 1 / 3 inches, 1 / 4 inches, 1 / 5 inches, and other specifications.
(2) description of the camera lens resolution imaging of intrinsic quality indicators is the optical lens distortion and transfer function, but the support, need to know is only the lens of spatial resolution, on a per-mm black and white stripes to tell a few For the units of measurement, calculated as follows:-resolution N = 180 / Picture format height. As CCD camera the size of the target has been standardized, such as 1 / 2 inch camera, the target of 6.4 mm * for high-4.8 mm, 1 / 3 inch camera-4.8 mm * high 3.6 mm. So the 1 / 2 inch format CCD target surface, the minimum resolution of the camera for 38 pairs of lines / mm, to 1 / 3-inch format camera, the lens of the resolution should be more than 50 pairs of lines, the camera The smaller the target surface, the higher the resolution of the camera.
(3) focal length of the lens and angle of vision to be the first under camera surveillance of the target distance, choose the focal length lens, lens focal length f determined by the camera determines the target of vision.
(4)-aperture or the amount of light the lens of the amount of light-to-lens focal length and aperture ratio to measure, marked with F, each lens are those with the largest of its F value, the amount of light and F-value of the square into Inverse relationship, F value of the smaller, the greater the aperture. Therefore, should be monitored in accordance with changes in light of the extent to choose to use automatic or manual aperture lens aperture.
3, zoom (zoom lens) zoom lens with manual and automatic retractable telescopic lens two categories. As a telescopic lens, lens focal length of the lens to make a certain scope change, so can be monitored so that the goal of zoom in or out, so it is often a variable power lens. Typical optical zoom specifications are six times (6.0 ~ 36 mm, F1.2), 8-fold (4.5 ~ 36 mm, F1.6), 10 times (8.0 ~ 80 mm, F1.2), 12 times (6.0 ~ 72 mm, F1 0.2), 20 times (10 ~ 200 mm, F1.2), and other grades, and with electric telescopic lens of the most common. To increase magnification, with the exception of optical amplification, could also impose electronic digital zoom. In the electric telescopic lens, aperture adjustments to three, namely: automatic diaphragm, DC-driven auto-aperture, the electric adjustment aperture. Its focus and variable power adjustment, only two electric adjustments and preferences, electric adjustment of the lens by the motor-driven, and the preferences is through the lens of the potential of pre-set adjustment stop bit, which would remove imaging Successive adjustment process must be fast and accurate positioning. Cover integration in the spherical camera system, most of the use of preferences with telescopic lens. Another users interested in focusing function is fast, it measured by the Coke system and the electric zoom a feedback control system.
4, CCD camera lens and the relationship between the size of 1 / 2 "lens can be used 1 / 2" video camera, can also be used for 1 / 3 "camera, but the perspective will be reduced by 25 percent. 1 / 3" lenses can not be used for 1 / 2 "video camera, only for 1 / 3" cameras.
5, different types of lenses on the application of
* Manual, automatic lens aperture on the application of manual aperture lens is the most simple lens for the light conditions of relative stability under the conditions, manual aperture from a few thin metal films. Flux through the lens diameter of a regulation ring. This circle will rotate at small aperture in or out. Lighting conditions change in the environment or is not used to monitor a fixed target, the lens aperture should be used automatically, for example, in outdoor or artificial lighting often switch places, automatic aperture lens aperture of the action by the motor-driven, motor control Cameras in the video signal. Manual and automatic lens aperture has set focal length lens aperture (Aperture) Lens Auto aperture of the lens and electrical zoom lens points.
* There will be a focal length (aperture) lens, the camera shutter in general and electronic support, apply to the interior of a fixed target of the surveillance role of places. The lens focal length divided into general and long focal length lens, lens focal length and short focal length lens. In focal length lens focal length and size similar to the imaging camera; imaging focal length is less than the size of the lens known as the short-range, short focal length lens also known as the wide-angle lens, the lens focal length is usually below 28 mm lens, the short focal length lens is used for lighting environment Poor, requiring wide area surveillance of the occasion, the focal length is greater than the size of imaging known as the long focal length lens, has a long focal length lens also known as the first telescopes, such lens focal length of 150 mm and above in general, mainly used for surveillance over a distance of the scene.
* Manual lens aperture, shutter cameras and electronic support, under various light can be used.
* Auto aperture lens, (EF) CCD camera with any supporting, in a variety of light can be used, especially for being watched surface brightness changes, the scope of the larger establishments. In order to avoid Halo phenomenon and burn target surface, usually with automatic lens aperture.
* Electric zoom lens, and any supporting CCD camera, can be used under various lighting, zoom lens through a remote control device for light focusing, aperture opening to change the size of the focal length.
6, the lens of the main performance indicator in the following:
(1) focal length: the size of the focal length determines the field of view of size, the focal length numerical small field of view, the scope of observation, but the distance does not clearly distinguish between objects; focal length value, small field of view , Observation of the small, as long as the appropriate choice of focal length, even from very far away objects can be seen clearly. As the focal length and field of view is one-to-one, a fixed focal length means a fixed field of view, in the choice of focal length of the lens, we should fully consider the details of important observations, there is still a large scope of the important observation, If depends on the details on the choice of long focal length lens, if we recognize the great scenes, the focus on the choice of small wide-angle lens.
(2) aperture factor: the luminous flux, with F, with the lens focal length f and the D-aperture ratio to measure. Each lens are those with the largest F values, such as 6 mm/F1.4 represents the maximum pore size of 4.29 mm. Flux and F value is inversely proportional to the square of relations, F value is, the greater the luminous flux. Lens aperture on the index value for the standard sequence of 1.4,2,2.8,4,5.6,8,11,16,22, its former law is a standard value of the exposure happened to be after a standard value of the corresponding exposure 2 Times. This means that the lens-aperture are 1/1.4, 1 / 2, 1/2.8, 1 / 4, 1/5.6, 1 / 8, 1 / 11, 1 / 16, 1 / 22, the former is a numerical After a value of 2 times the root, so the smaller the aperture index, the larger-aperture, the imaging surface of the target the greater illumination. In addition there are manual lens aperture (MANUAL IRIS) and automatic aperture (AUTO IRIS) of the points. With the use of video cameras, manual aperture for little change brightness of the occasion, the amount of light into it through the lens aperture ring conditioning, a one-time adjustment of the appropriate date. Auto aperture lens with the light of the changes will be automatically adjusted for outdoor, importers and other large and frequent changes in the light of the occasion.
(3) Auto aperture lens: Auto aperture lens currently divided into two groups: those known as video (VIDEO)-driven, the camera itself contains amplifier circuit, which will be transmitted from camera video signal conversion rate of the motor paired aperture Control. Another called the DC (DC)-driven, using camera to the head of the DC voltage direct control over aperture. Such lenses include only the current or diaphragm motor for a camera, amplifier circuit. For all types of automatic lens aperture, usually there are two adjustable knob, First ALC adjustment (meter-conditioning), to peak metering and in accordance with the objective conditions of the average LED metering two options, general admission average metering file; Another adjustment is LEVEL (sensitivity), the output can become bright or bleak image.
(4) variable power lens: variable power into the camera manually (MANUAL ZOOM LENS) and electric (AUTO ZOOM LENS) are manually variable power-general for research projects rather than in-house surveillance system. The great scenes in monitoring, the camera usually with the use of electric-and PTZ. Electrical zoom lens has the advantage of the scope, we can see a wide range of circumstances, can also be a focus details, together with the PTZ can turn around from top to bottom, the visual scope is very big. Electric-six times, 10 times, 15 times, 20 times, and other rate, the benchmark to know if the focus on the focal length of the lens to determine the scope of the variable. For example, a six times the electrical lens, the benchmark for the 8.5 mm focal length, its zoom range is 8.5 to 51 mm continuous-tuning, field of view for 31.3 to 5.5 degrees. - Voltage electrical control is generally DC 8 V ~ 16V, the most current of 30 mA. Therefore, the election controller, it is necessary to give full consideration to the length of transmission cable, if the distance, the line voltage drop would lead to the lens can not control, to be on the input control voltage or replacement of video decoder with host matrix control.

  Matching Lens principles:
     In order to obtain the desired effect of cameras in matching the lens, they should focus on six basic elements:
     A) the size of objects being perturbation
     B) the details of the size of objects perturbation
     C) of distance
     D) focal length
     E) CCD camera the size of target
     F) lens and camera system resolution
The focal length of terms: formula law: the focal length of the field of view and field of view means the calculation of intake was the size of objects, field of view lens is the size of objects from the intake to be, coke-head and the requirements of the imaging determine the size. 1, lens focal length, depending on market size and the lens into the intake of objects from the calculation as follows; f = wL / W 2, f = hL / h
f; focal length of the lens
w: the width of images (perturbation was the target objects in ccd imaging surface width)
W: the width of objects perturbation
L: perturbation objects to be the distance between the lens

h: Image height (perturbation was the target objects in ccd imaging surface height) field of view (intake scenes) high
H: the object was a high degree of perturbation
   ccd target surface Dimensions: flat mm specifications
Specifications 1 / 3 "1 / 2" 2 / 3 "1"
W 4.8 6.4 8.8 12.7
H 3.6 4.8 6.6 9.6 intercept after the adjustment of the lens
Coke intercept after the adjustment of the lens
The use of automatic electronic camera shutter function, the camera will be transferred to maximum aperture, the camera focused on Central features the actual distance adjustment, and then adjust the camera until after the intercept of the clearest image. Zoom after the adjustment of an intercept. Automatically open the electronic camera shutter function.
2. Controller with the lens aperture transferred to the largest.
3. Camera will be at 30 meters away from the object, focusing transferred to infinite distance (most of the lens of the camera is focused conditioning Central clockwise rotation end).
4. Controller adjustment with zoom lens features will be pushed to the farthest, after the adjustment of the lens to intercept the features clearly.
5. Controller with zoom lens will be adjusted to pull the last scene, the camera focused fine-tuning the features most clearly.
6. Repeat steps 4 to 5 times, until the scene in the process of zoom lenses always clear.
                   Image transmission mode of control
  In the monitoring system to monitor the image of the entire transmission system is a vital aspect of the choice of media and image transmission equipment and other control signals will be directly related to the monitoring system for quality and reliability. At present, the monitoring system used to transmit images in the media signals a major coaxial cable, fiber optic and twisted pair, the corresponding transmission equipment are coaxial video amplifier, twisted pair video transmission equipment and video optical transmitter and receiver . To the formation of a high-quality monitoring network, we must find out the three main modes of transmission characteristics and the use of the environment, so that works against the actual need for appropriate transmission medium and equipment.
1 coaxial cable and coaxial video amplifier
    Mentioned image transmission, people first of all think of the Federation of coaxial cable, as is the earlier use of coaxial cable, but also the use of the longest transfer method. At the same time, coaxial cable with cheaper prices, the laying of the advantages of more convenient, so, usually in small-scale monitoring system, since the proximity of transmission, the use of coaxial cable sent directly monitor the quality of images on the image little damage , To meet the practical requirements.
    However, according to the characteristics of its own analysis of coaxial cable, coaxial cable, when the signal transmission by the decay and its transmission distance and the frequency of the signal itself. Generally speaking, the higher the frequency, the greater attenuation. The great bandwidth video signals to 6 MHz, and, the color images were part of frequency modulation in the high-end, so that video signals in the coaxial cable transmission signal not only by the overall rate of decay, and decay of the frequency components are very , In particular the color of the largest decay.
Therefore, the coaxial cable transmission only suitable for close-up image signal, when the transmission distance of 200 meters, the image quality will be significantly decreased, especially the color has become dim, a sense of distortion.
    In engineering practice, in order to extend the transmission distance, to use coaxial amplifier. Coaxial video signal amplifier to a certain degree of amplification, and also through a balanced adjustment to a different frequency components were different sizes of compensation, so that the receiving end of the video output signal distortion as possible. However, coaxial amplifier cascade can not be unlimited, usually in a point-to-point system can be up to coax amplifier cascade 2-3, it can not guarantee the quality of video transmission, and it is very difficult to adjust. Therefore, the monitoring system using coaxial cable, in order to ensure a better image quality, the general will limit transmission distance in four or five hundred meters around.
    In addition, the monitoring system of coaxial cable transmission image signal there are still some shortcomings:
1), coaxial cable itself affected by climate change, image quality will be affected;
2), coaxial cable coarse, in the intensive monitoring applications, cabling is not easy;
3), coaxial cable-general can only video signals, if the system needs at the same time in the transmission control data, audio and other signals, you need wiring;
4), the limited capacity of coaxial cable interference, can not be applied to strong interference environment;
5), coaxial amplifier there is still a difficult adjustment of the shortcomings.
2 twisted pair and twisted pair video transmission equipment
    As the traditional coaxial cable monitoring system there are some shortcomings, especially the transmission distance limited, so seek an economic, high-quality transmission, transmission distance from the solution is very necessary. Early in the transmission distance over 5, 600 meters of the monitoring system in the general use of multi-mode and multi-mode optical fiber video optical transmitter and receiver , although this solved the problem of long-distance transmission, but increasing system costs a lot, and that the construction of complex fiber , Professionals and need special equipment. Therefore, this is not too far away from the monitoring system, the use of optical fiber and still is not enough economic video optical transmitter and receiver .
    Recently, there has been a twisted pair video transmission equipment, through the use of such equipment, twisted pair can be applied to monitor image transmission, a good solution to the above problems in the future monitoring system will be Large-scale use.
    In fact, the twisted pair of long-standing use of telephone transmission is the use of twisted pair, in many industrial control systems and interference in larger places, as well as long-distance transmission have used twisted pair, today we use the LAN The use of twisted pair is also right. The reason why such extensive use of twisted pair, because of its strong anti-interference capability, transmission distance, cabling easy, inexpensive, and many other advantages. Because of the twisted pair also exist in the larger signal attenuation, transmission distance, the frequency signal can not be too high, and high-speed signals such as Ethernet is only limited to 100 m within. For video signals, the bandwidth to 6 MHz, if directly in the twisted pair of transmission, will decay great, transmission distance of about 150 m when the video signal attenuation curve as shown below.
    Therefore, video signal on the twisted pair to achieve long-distance transmission, and compensation must be enlarged, twisted pair video transmission equipment is completed this function. With a twisted pair transceivers video equipment, you can transfer images to 1-2 km, if the use of metadata, can also multiplied transmission distance, and transfer the image quality comparable with video optical transmitter and receiver . Twisted-pair and twisted pair video transmission equipment prices are very cheap, not only did not increase system costs, but from the increased cost of its coaxial cable and down a lot. Therefore, the monitoring system using a twisted pair transmission has obvious advantages:
1) transmission distance, high-quality transmission. As the twisted pair transceivers used in the treatment of advanced technology, excellent compensation of the twisted pair of video signals and the rate of decay between the different frequency attenuation poor, to maintain the original image brightness and color as well as real-time, In the transmission distance to 1 km or longer, the basic image signal without distortion. If the relay, transmission distance will be farther away.
2) to facilitate wiring, cables high utilization rate. One pair of ordinary telephone lines can be used to transmit video signals. In addition, the extensive laying of the building housing the five types of non-admission of the unshielded twisted pair in a way you can send video signals, without wiring, even the re-wiring, Category 5 cable than coaxial cable easy. In addition, a Category 5 cable has four pairs of twisted pair, if you use a video signal transmission lines, and several of the line can also be used to transmit audio signals, control signals, power supply or other signals, improving the line Cable utilization, while avoiding a variety of separate signal routing the trouble to reduce the construction cost.
3) anti-jamming ability. Twisted pair can effectively curb the common mode interference, even in strong interference environment, twisted pair also transmits an excellent image signals. Moreover, the use of a rope in a few of the twisted pair were sent different signals, there will be no interference with each other.
4) high reliability, ease of use. Twisted pair transmission of video signals, in front of exclusive access to the transmitter, the control center to access special receiver. This twisted pair transmission equipment are cheap, very simple to use, no expertise, nor too much of the operation, once installed, long-term stability.
5) are cheap, easy subjects. As the use of the current widespread use of the five general categories of non-shielded cable or ordinary telephone lines, easy to buy, but prices are cheap, to the works of great convenience.
3 fiber and video optical transmitter and receiver
    video optical transmitter and receiver  used in fiber and monitor the field is to solve two problems: First, transmission distance, the first environmental interference. Twisted-pair and coaxial cable can only solve short-range, small within the scope of monitoring image transmission, if necessary transmission several kilometers even hundreds of kilometers from the image signals the need for a fiber optic transmission. In addition, the interference of some super places, in order to not interfere with environmental impact, we should also use optical transmission methods. Fiber bandwidth because of wide, large capacity, free from electromagnetic interference from outside environmental impact of small, and many other advantages of an optical fiber can send monitoring system needs all the signals, transmission distance can reach 100 km. video optical transmitter and receiver  can provide all the way and multi-channel image interface, can also provide two-way audio interface, and all the way various types of multi-channel two-way data interface (including RS232, RS485, Ethernet, etc.), they will be integrated into an optical fiber On the transmission. video optical transmitter and receiver  monitoring system to provide a flexible transmission , signal quality, high stability. In recent years, due to fiber the rapid development of communication technology, fiber optic and optical devices to lower prices quickly, making the cost of fiber optic monitoring system substantially reduced, fiber and video optical transmitter and receiver  in the monitoring system of growing popularity.
    Fiber is divided into multi-mode fiber and two single-mode optical fiber. Multimode fiber dispersion and attenuation due to larger, the largest of its transmission distance generally can not exceed 5 Km, therefore, in addition to previously has paved the multimode fiber place, in new projects is no longer in general use of multi-mode optical fiber, and the main The use of single-mode optical fiber.
    Fiber transmission signals to monitor the use of video optical transmitter and receiver , its main role is to achieve power - light and light - power conversion. video optical transmitter and receiver  video optical transmitter and receiver is divided into analog and digital video optical transmitter and receiver :
1) simulation video optical transmitter and receiver 
    Simulation video optical transmitter and receiver  PFM modulation technique used real-time image transmission signal, is the use of a more. The transmitter will be carried out analog video signal modulation PFM, to conduct electricity - light conversion, the optical signal reached the receiver, a light - power conversion and then proceed to PFM demodulator, to restore the video signal. As a result of the PFM modulation technology, transmission distance can be easily reached about 30 Km, some products of the transmission distance can reach 60 Km, or even hundreds of kilometers. And, after the image transmission signal distortion is very small, with very high signal to noise ratio and small nonlinear distortion. By using WDM technology, but also in the realization of a fiber image and data signals in the two-way transmission, monitoring projects to meet the actual demand. However, this simulation video optical transmitter and receiver , there are some drawbacks:
a) more difficult to debug production;
b) a single optical fiber to achieve multiple image transfer more difficult, performance will drop, the current analog video optical transmitter and receiver  can only be a single optical fiber transmission on the four-way image;
c) As used in analog modem technology, its stability is not high enough, with the increase in the use of time or special environment
Of the changes, video optical transmitter and receiver 's performance will change, to cause some inconvenience to the use of works.
2) Digital video optical transmitter and receiver 
    As digital technology with traditional analog technology in many ways compared to a clear advantage, so as digital technology in many areas to replace analog technology, digital video optical transmitter and receiver  is also an inevitable trend. At present, digital image technology video optical transmitter and receiver  There are two main ways: One is the digital image compression MPEG II video optical transmitter and receiver , a non-compressed digital image video optical transmitter and receiver .
Digital image compression by MPEG II video optical transmitter and receiver  general image compression technology, it can image compression activities into the N ¡Á 2Mbps data flow through the communication interface standard telecommunications transmission, or directly through optical fiber transmission. As a result of the image compression technology, it can greatly reduce signal transmission bandwidth in order to facilitate occupation of fewer resources to send image signals. At the same time, the use of the N ¡Á 2Mbps standard interfaces, we can use the existing telecommunications transmission equipment monitoring the affluent image transmission channel for the application has brought convenience. However, digital image compression video optical transmitter and receiver  also has its inherent weaknesses. Its fatal weakness is no guarantee that the real-time transmission of images. Because image compression and decompression need a certain amount of time, generally by the transmission of images to produce 1 ~ 2 S delay. Therefore, this equipment is only suitable for use in real-time do not need higher on the premises, the project subject to some restrictions on use. In addition, the compressed image will produce a certain distortion, and the price of such video optical transmitter and receiver  High.
    Uncompressed digital image video optical transmitter and receiver  principle is the analog video signal A / D and transform voice, video, data and other signals multiplexer, and then through the optical fiber transmission. With its high data rate video signals to ensure that the transmission quality and real-time, the very large bandwidth of fiber, so this is also high data rate transmission channel has not put excessive demands. video optical transmitter and receiver  uncompressed digital images can provide good quality image transmission (such as minimally invasive Wuhan Photoelectric Technology Co., Ltd. video optical transmitter and receiver  non-compressed digital signal to noise ratio greater than 60 dB, differential phase distortion of less than 2 ¡ã, DG Distortion of less than 2 per cent), to broadcast the transmission quality and image transmission is the real-time. As a result of digital technology, the device can use the already very mature communication technologies such as the multiplexer, video optical transmitter and receiver technology, improve the reliability of the equipment, but also reduce costs. Uncompressed digital image video optical transmitter and receiver  reflected in the advantages:
a) the use of digital technology has greatly improved the quality of image transmission;
b) digital technology and the use of large-scale integrated circuits to ensure that the equipment work of the stability and reliability, have overcome the shortcomings of analog video optical transmitter and receiver ;
c) will not have a transmission delay to ensure the monitoring of real-time images;
d) can easily be multiple images and audio, data and other signals through an integrated fiber optic transmission, at present, this non-compressed digital image video optical transmitter and receiver  can be done in one-way transmission dozens Road, Even hundreds Road images (such as minimally invasive Optoelectronic Technology Co., Ltd., Wuhan non-compressed digital video optical transmitter and receiver  in the single fiber, 64-way image transmission).
    video optical transmitter and receiver  digital image of high technology content, in its monitoring of the use of time is not long, mostly used in multi-image transmission, mainly due to the currently able to provide such video optical transmitter and receiver  of the manufacturers is not more , The relative price in terms of simulation video optical transmitter and receiver  also slightly higher. However, the digital image video optical transmitter and receiver  especially non-compressed digital images video optical transmitter and receiver  obvious advantages, coupled with the large-scale use will reduce costs, simulation video optical transmitter and receiver  will soon be replaced by digital images video optical transmitter and receiver .
4 Conclusion
    In addition to monitoring signals transmitted images over on the three main modes, but also some works in the use of a point-to-point wireless transmission and cable used on multiple sub-carrier radio transmission reuse. Wireless transmission by too much impact on the environment and climate, job insecurity, equipment installation and adjustment difficulties; multiple sub-carrier radio transmission multiplexing equipment in need of more stability, not high, the image of poor quality, equipment installation is also adjusted Difficulties. Therefore, these two devices use very little, not recommended users. The coaxial cable, fiber optic and twisted pair of three transmission mode, the user can choose according to project the actual situation. Generally speaking, in the distance, 300 meters, and the environment without interference, routing a large space of the place, consider using cable when the transmission distance in less than two kilometers, or environmental interference, cabling is demanding a tight place, Recommend the use of twisted pair; distance to several kilometers or farther away, the fiber is a natural choice. Of course, the actual works, many users regardless of distance, in the same projectͳͳthe use of optical fiber, the distance or close to the project of the use of twisted pair, which works entirely by the actual needs identified.
Recommended for beginners - Optical term in bilingual
   
Aperture (Iris): located within the camera lens, you can adjust the optical-mechanical Lang, can be used to control the light through the lens of how many.
Variable aperture (Iris diaphragm): click on the camera used to control the internal hole the size of mechanical devices. Or means used to open or close the lens Lang hole, thus adjusting the lens of the f-stop devices.
Isolation amplifier (Isolation amplifier): input and output circuits have been specially designed to avoid each other of the two amplifiers.
Jitter (phenomenon) (Jitter): because of mechanical interference or power supply, and other components of the changes caused by signals of instability, may signal instability on the amplitude or the phase, may also be both.
Lag (Lag): Like the TV away, the removal of excitation, two or more frames in charge of the image brief stay.
Laser (Laser): Light amplification by stimulated emission of radiation acronym. Laser is an optical resonator, at both ends with plane mirror or mirror ball, equipped with optical amplification intermediate materials. It uses optical or electrical methods which stimulate the material to make atomic material to produce a bouquet of excitation light, light through the end of the mirror fired up.
The output beam is highly monochromatic (solid color) and non-proliferation in nature.
Front (Leading edge): increased pulse of the main part of its general position in the amplitude of the 10-90 per cent.
Lens (Lens): from one or more tablets Globoidal (usually spherical) composed of optical glass transparent optical components. It can be used to gather or distributed by a perturbation of the light, thereby generating the perturbation of the real or imaginary, as like.
Lens, Fresnel ~ (Lens, fresnel): Zaida ring was cut into narrow-lens. Lens on a Loop concentric circles or the narrow stairs, they can be (in all directions to the radio) light Huiju Cheng image.
Lens speed (Lens speed / f-number): the transmission capacity of the camera. F value is the focal length (FL) and the ratio of the lens diameter. The faster the value of the lens may be f / 1.4, and f / 8 lens, its speed is quite low. f value is, the slower the speed of the camera.
Lens System (Lens system): refers to two or more lens of the organic combination.
- (Light): eyes can see that the electromagnetic rays, the wavelength of 400 nm (blue) to 750 nm (red) range.
Limited resolution (Limiting resolution): Resolution of measurement methods, usually by television images of each test pattern can be resolved on the television to a few lines of that.
Line amplifiers (Line amplifier): used to drive transmission line of audio or video signal amplifier. Installed in the middle of the main cables, to reduce wear and tear of the amplifier (usually broadband-type).
Linear (Linearity): output signal with the input signal changes, either directly or in proportion to changes in the phenomenon.
On the line (Line pairs): the definition television definition used by the terminology. A TV lines of a black line and a white line component. 525-line NTSC screen a total of 485 line right.
Load (load): bear by the equipment the output energy components.
Loss (loss): signal level or intensity of the reduction in decibels that are usually used. Also did not refer to actual use of the power dissipation.
  Low-frequency distortion (Low-frequency disortion): low frequency of distortion. Television system in general refers to the following frequency of 15.75 kHz.
Minimum illumination cameras, television Minimum illumination (Low light level / LLL camera and television): extremely weak in the light of the work of the CCTV cameras. In the normal visual response to light the circumstances of the CCTV system.
Lumens (Lumen / Im): luminous flux units. A candlelight vigil at the point of radiation sources through a uniform three-dimensional angle (sphere) of flux, the equivalent of a candlelight vigil at the uniformity of all the sources equidistant on the surface of the luminous flux.
Illumination (Luminance): from the same direction, in a given direction on any surface area per unit projection on the light intensity (brightness). Flat feet Lambert. Brightness signal (Luminance signal): NTSC color television signals involved in the scene illumination or brightness that part of signal.
Flux (Luminous flux): Light at the rate of adoption.
Döllekes (Lux): the International System of Units in the lighting unit, which relates to the length of units meters. 1 Döllekes equivalent to 1 lumens per square metre.
Magnetic Highlights (Magnetic focusing): magnetic field to make use of electron beam Convergence approach.
Electrostatic Highlights (Electrostatic focusing): through the lens of the electronic system of one or more elements impose electrostatic potential, cathode-ray beam is focused onto a small way.
Magnification (Magnification): that the perturbation of the size and image differences between the figures. Usually for 1-inch focal length lens and the target surface to 1-inch size of the sensor as the base (magnification = M = 1). 2-inch focal length lens magnification for the M = 2.
DG (Differential gain): When the 3.58-Mhz contains a color image of the carrier signal from blanking level, usually a white, the color of the circuit carrier amplitude changes. DG is usually used to measure the percentage or dB.
Differential phase (Differential phase): When the 3.58-Mhz contains a color image of the carrier signal from blanking level, usually a white, the color of the circuit carrier phase changes. Differential phase usually for the unit of measurement.
Diopter (Diopter): description of optical lens power terminology. Its value is the focal length of the meter as a unit value of the countdown. For example, the focal length of 25 cm (0.25cm) of the optical lens power for four diopter.
Electric distortion (Distortion electrical): a signal when compared with the original signal, the wave does not want the change.
Optical distortion (Distortion, optical): Image is not used to describe the exact reproduction of objects in general terms. Distortion of a number of different types.
Point Strip signal generator (Dot bar generator): a special point of the signal equipment. Generally used to measure television cameras and video monitors scanning linear and geometric distortion.
Pulse drive (Drive pulses): that synchronization pulse and blanking pulse.
Dynamic range (Dynamic range): TV systems, cameras practical means of illumination. In this case, the perturbation in the field of view at the same time zones exist glare and shadows, and all the details are clear. Number of general illumination to allow the maximum and minimum levels of illumination level of power or voltage difference poor to measure.
Echo (Echo): the process of signal transmission from one or more points back reflection of the signal. Compared with the original signal, with clear time and the extent of the differences. Echo can advance than the original signal or tardy, causing reflected wave or "ghost" phenomenon.
EIA interface standard (EIA interface): from the Electronic Industries Association (EIA) provides a series of standard signal characteristics, including duration, waveform, such as voltage and current.
EIA sync signal (EIA sync signal): Electronics Industry Association in the RS-170 (monochrome image) standard, RS-170A (color image) standard, RS-312, RS330, RS-420 and continued after the stipulated in the document, Used to scan synchronization signal. Electromagnetic aggregation (Electromagnetic focusing): the use of electronic lens system of one or the number of deflection coil, electromagnetic field through the role of cathode-ray beam Convergence will be a point of the process.
   
Plane Image (Image plane): the imaging point, and the optical axis vertical plane.
Impedance (Impedance): electronic circuit or device input / output characteristics. To achieve the best results signal transmission, used to connect the two cable circuit or device with the characteristic impedance of the circuit or device impedance of the same characteristics. Ohm impedance for the unit. Video distribution systems using the standard two coaxial cable.
Laser line (Incident light): direct exposure to light on the object.
Infrared radiation (Infrared radiation): more than 750 nanometer wavelength (visible spectrum red side), less than microwave wavelength not visible.
Enhance the charge-coupled device (Intensified CCD / ICCD): through the tube and fiber-or micro-channel plate image intensifier connected to the CCD camera.
Enhanced silicon target (Intensified silicon intensified target / ISIT): through the enhancement of fiber and additional devices connected to enhance the sensitivity of the SIT. Two-level increase even use, the availability of the sensitivity of the camera as the standard of 2000 times.
Enhanced cameras (Intensified vidicon / IV): through optical fiber and enhanced device connected to enhance the sensitivity of direct reading of the standard camera.
Interference (Interference): tend to disturb the signal to obtain external spurious signals.
Interlaced scanning, 2:1 ~ (Interlace, 2 to 1): closed-circuit television system used in a scanning technology. Among them, two from each frame image composed of two field to the rate of 2 to 1 precisely synchronized scanning, connected in the field adjacent scanning between the lines of time or phase relationship is fixed.
Random staggered (Interlace, random): closed-circuit television system used in a scanning technology. The composition of the two frames are not synchronized, the associated field adjacent to the time or phase is not fixed. .
Of aperture / F value (f-number): the transmission capacity of the camera. F value is the lens focal length (FL) and the perimeter of the incident pupil (D) ratio, that is, F = FL / D. F value and is directly proportional to the focal length, and the lens is inversely proportional to the perimeter. F value is, the better the performance of lens transparency.
Focal length (FL): Lens centre or second plane to image the main focus of the distance. FL units generally mm or inches.
Focal length, after ~ (Focal length, back): Lens after the peak to the distance between lens focal plane.
FPA (Focal plane): with the lens or mirror at right angles to the main focal point and through the plane, the plane generated images the best.
IP equipment dust rate is an indicator of water. The indicators in Europe and the United Kingdom in the frequent use of products, by two digits. The former is a solid indicator of defense, after a liquid on the defensive targets. And shields on the IP rate: IP55: dust, but will enter a small amount of dust limited. From all directions to prevent the low-pressure water, but will be limited access to small amounts of water.
IP65: dust, the dust will not enter. From all directions to prevent the low-pressure water, but will be limited access to small amounts of water.
IP66: dust, the dust will not enter. From all directions to prevent the high-pressure water, but will enter a small number of limited water.
The basic knowledge on video
According to trichromatic principle, in the field of video R (red), G (Green), B (blue) of three different colors to the mixed performance of a variety of the real world. First of all, through the photosensitive devices like cameras CCD (charge-coupled device), light signals into three-way RGB signals Secondly, the television or monitor the use of RGB signals within the control of three separate gun bombardment screen to produce images So that in the original signal because of the camera and television sets, monitors are in the final signal RGB signal, the direct use of RGB signals as a video signal transmission and recording methods will be very high signal quality. However, this would greatly widen video equipment to increase bandwidth costs, and this is also not compatible with the existing black-and-white TV, so in practical applications do not do so, but the brightness equation Y = 0.39R +0.5 G +0.11 B (PAL system) RGB signals into light signals Y and the two color signals U (BY), V (RY), a component YUV signals. Such signals of the human eye on the details of brightness and high-resolution color details on the characteristics of the low resolution of the U, V bandwidth signal compression. U, V may be further signal of a color signal C, thus forming Y / C recording. Since records to take down the C-frequency signal processing, also known as down-color mode. Y and C can be further form a composite video (Composite), that is, full-color television signals, in this way facilitate the transmission of television signals and fired. RGB signal will be converted into YUV signal, Y / C signal until the process is known as the composite signal coding, reverse the process of decoding. This can be seen, because the number of conversion steps, the quality of video output from the port to YUV Y / C port to port Composite were lower. Therefore, the video capture or output choose a suitable input and output ports can enhance video quality. In addition, the signal should also be provided simultaneously send images to ensure stable reproduction.
Video clips are known as the frame by a series of still images of a single component. General frame-rate in the 24-30 frames / s, the video movement is very smooth, but lower than 15 / sec there will be stalled when the flu. In the PAL system, provides 25 / sec, each frame of 625 scanning lines (the odd-numbered lines, even lines, that is surprising even two, the use of interlaced scan mode). In each frame, the electron beam from the upper left corner of interlaced scan to the bottom right corner after SKIP to the upper left corner of a reverse way, scanning the entire time about 8 percent, effective line of 625 to 576 lines only, that is, vertical Resolution 576 points. Under the current 4:3 TV standard, the standard resolution of 768 points, and this is a common resolution 768 * 576. In addition, there is a follow CCIR601 standard PAL system and its resolution is 720 * 576. The NTSC system, provides 30 / s, 525 line / frame, interlaced scanning, the odd, even two, the image size of 720 * 486. NTSC and PAL system because of different treatment methods, incompatible with each other. Each video frame determine the location and time duration of video clips, using a special standard time encoding format SMPTE time code, said the "H: M: S: F", namely ": min: sec: frame."
    PAL-NTSC system and are generally analog signals, to be completed video capture card of its A / D converter. video capture card first to enter the video signal sampling to 4:2:2 format, and then quantify, the general YUV (that is, the RGB) of 8 bit to quantify and therefore have a true color 24. As a digital image after the considerable volume of data, in order to save storage space, but also their compression. Compression can be divided into lossy compression and lossless compression, while the former at the expense of image detail for the price. Compression can be soft and hardware, which can achieve real-time compression, while the former are often in resolution, color depth, such as frame rate and make some sacrifices. Choice of compression ratio, the higher the compression ratio, the worse the image quality. Through this process, that is, analog video into digital video, and the process can reverse the process of the realization of digital video compression and playback. In addition, the use of certain video capture card  input and output settings, easy to achieve NTSC and PAL system conversion system.
  The digital video compression solution, the card can be sent to the computer and displayed on the monitor. In the computer's display showed that precision digital video, video display mode must be made with the type of digital video to match. Because there is a kinescope display brightness signals in the non-linear, so the image signal must be sent in advance of compensation, which is ^ correction, only to have an impact on the middle tones. The general computer monitor ^ 1.8, and the image of the PAL system ^ ¦Ã value is about 1.8, little influence on the image of the NTSC system ^ ¦Ã value of 2.2, if we do not show images will be adjusted white.


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