The so-called gun camera is only for the appearance of distinction, this is the camera's initial form, in fact, the camera board + housing, without the lens, can freely match various models of the lens. Mounting methods can be used for hoisting or wall mounting. Outdoor installations are generally equipped with protective hoods. Currently, these cameras are mainly used in special areas and high-end areas. The middle and low-end areas are basically replaced by one-piece machines and hemispheres. The gun type is mainly suitable for areas where lighting is not sufficient and where lighting equipment cannot be installed at night. A gun camera may be used when monitoring the position or movement of the scene. Gun-type cameras have a wider range of applications. According to the choice of lenses, remote monitoring or wide-angle monitoring can be realized. The application occasions are wider than the hemisphere. The zoom range of the guns depends on the lens used, and can be several times Dozens of times, and the replacement of the lens easier, in addition to the need for a bolt if you need to configure the protective cover.
Basic function analysis 1. The number of pixels refers to the maximum number of pixels of the gun camera CCD sensor, and some of them give the number of horizontal and vertical pixels, such as 500H × 582V, and some of them give the value of the wait for the first two products, such as 300,000 pixels . For a CCD chip of a certain size, the larger the number of pixels, the smaller the area per pixel unit, and the higher the resolution of a gun camera composed of the chip.
2. The resolution resolution is an important parameter to measure the advantages and disadvantages of the black-and-white gun cameras. It refers to the fact that when the gun camera captures black and white stripes arranged at equal intervals, it can be seen on the monitor (which should be higher than the resolution of the camera). The maximum number of lines, when it exceeds this number of lines, the screen can only see a gray piece and can no longer distinguish the black and white lines.
The resolution test usually uses a gun camera to capture a resolution test card and read the data through a waveform monitor. The specific method is as follows:
(1) Arrange the test environment. Place the resolution test card on the standard test light box, about 3m away from the camera. The video output of the gun camera is connected to a waveform monitor and the output of the waveform monitor is connected to a high resolution black and white monitor.
(2) The illuminance of scenery is set to 2000lx, and the color temperature of the light source is set to 3200K.
(3) Adjust the lens focal length (or select the appropriate fixed-focus lens and move the camera forward or backward slightly) to fill the monitor screen with the image of the resolution card and sharpen the image with precise focus.
(4) Observe the resolution card with the selected oscilloscope to get the waveform.
(5) Adjust the lens aperture so that the signal white level reaches 100% (70mV). At this time, the number of TV lines whose modulation is deeper than 5% is the limit resolution.
3. Minimum Illumination Minimum Illumination is also an important parameter to measure the merits of gun cameras, sometimes omitting the word “lowest†and directly referred to as “illuminanceâ€. The minimum illuminance is a luminosity value of the scene when the illuminance of the subject is low to a certain extent and the level of the video signal output by the gun camera is as low as a predetermined value. When measuring this parameter, the maximum relative aperture of the lens should also be specified. For example, with an F1.2 lens, when the brightness of the subject is as low as 0.04LX, the amplitude of the video signal output by the camera is 50% of the maximum amplitude, ie, 350mV (the maximum amplitude of the standard video signal is 700mV. ), the minimum illumination of this gun camera is called 0.04LUX/F1.2. The brightness value of the subject was low, and the amplitude of the video signal output by the gun camera was less than 350mV. Reflected on the screen of the monitor, it would be a gray image with a hardly distinguishable level.
At present, due to the fact that the market's specifications are not yet uniform, the low illumination characteristics of some gun cameras with low illumination indices may not be as good as the low illumination characteristics of gun cameras with slightly higher illumination indexes. The reason for this is that the standards used for measuring the low-lightness index are different. Still taking the aforementioned example as an example, if the video signal amplitude output by the camera is reduced to 30% of the maximum amplitude (that is, 210 mV) as a reference, the brightness value of the imaged object can be further lowered, such as 0.03LX. If the optical lens is further replaced with an F1.0 lens, the luminous brightness of the subject can be further reduced due to the increase of the luminous flux, such as 0.02LX.
It can be seen from the above analysis that it is impossible to accurately determine which camera has low illuminance characteristics by putting aside the measurement standard and simply comparing the illuminance nominal value of a certain brand of gun camera with the illuminance nominal value of another brand of gun camera. Good conclusions, because the relative aperture of the lens they use and the specified value of the output video signal may not be the same. Therefore, the minimum illumination index can only be used for reference when designing and purchasing equipment.
4. The SNR is also one of the main parameters of the gun camera. When a gun camera captures bright scenes, the screen displayed by the monitor is usually brighter, and observers cannot easily see the interference noise in the screen. When the camera captures a dark scene, the screen displayed by the monitor is darker. At this time, it is easy to see snow-like noise in the picture. The strength of the interference noise (that is, the degree of influence of the interference noise on the picture) is directly related to the quality of the gun-type camera signal-to-noise ratio. That is, the higher the signal-to-noise ratio of the gun camera, the greater the influence of the interference noise on the picture. small.
The so-called "signal-to-noise ratio" refers to the ratio of the signal voltage to the noise voltage, which is usually represented by the symbol S/N. Since in general the signal voltage is much higher than the noise voltage, the ratio is very large. Therefore, the actual calculation of the camera signal-to-noise ratio is usually based on the ratio of the mean squared signal voltage to the mean square noise voltage. The number is multiplied by a factor of 20, that is, the unit of equation (2-3) is expressed in dB.
The signal-to-noise ratio given by the general gun camera is the value when the AGC (automatic gain control) is turned off, because when the AGC is turned on, the small signal is boosted, so that the noise level is also increased accordingly. The typical value of CCD gun camera signal to noise ratio is generally 45dB ~ 55dB. When measuring the SNR parameter, a video clutter measuring instrument should be used to connect directly to the video output terminal of the gun camera.
Gun-type camera features Gun-type camera powerful, widely used, cost-effective, with the following characteristics:
In recent years, with the extensive application of security surveillance cameras, high-definition gun camera imaging technology, high-definition fog function, infrared detection lock, day and night conversion infrared camera functions have been widely used in television monitoring projects. The day and night conversion infrared camera function of the gun-type camera enables the camera to perform filter switching between day and night, detect infrared light, and solve the frequent day and night conversion problem of ordinary day and night cameras. It can effectively reduce image noise in nighttime low illumination environments and improve picture quality. The zoom range of the gun camera depends on the lens you choose, from several times to ten times, and the lens replacement is very convenient. According to the choice of different lenses, to achieve long-distance or wide-angle monitoring, there are many applications. In the use of road monitoring, even if the range of vehicle speed changes is large, the bolt camera can also provide a clear picture. Through the built-in light suppression function, manual electronic shutter settings, to achieve the license plate capture. It can truly reproduce nighttime dynamic scenes, and is suitable for places such as highways, toll stations, and safe cities that are monitored 24 hours a day.
Installation Tips 1. Familiar with product performance The project owner and user should be familiar with the product's technical parameters, such as how much the input voltage is, how big the power is, and what functions it has.
2. Check the hemisphere camera for detection and adjustment before installation so that the camera is in normal working condition.
3. Installation Method Before construction, installation methods such as wall mounting or hoisting may be adopted according to the environment, safety, and aesthetics.
4. Installation Angle The installation angle of the gun camera directly affects the scope of the monitoring image, so the installation needs to be more in accordance with the needs of the field. If installed at the entrance of the cell is less than 6 meters, the camera's angle is recommended to be 30 ° -60 °; if installed in the cash register, the camera's angle should be considered in the ± 15 ° -20 ° and so on. In short, the camera avoids the appearance of backlighting as much as possible, so that it can reach the customer's requirements as much as possible.
5, do a good job of video interface processing camera video signal output port, power input port, control signal port is more important, the installation should be as good as possible waterproof, and anti-oxidation treatment. In order to avoid instability, uncontrolled, or even display images in the future.
Maintenance Tips 1. Maintaining the basic conditions The old saying is good, “A woman is a no-nothing woman,†and the same is true for the maintenance of a gun camera system. The basic maintenance conditions for a normal maintenance of a gun camera system are required. That is to achieve "four Qi", that is, spare parts Qi, accessories Qi, tools Qi, instruments Qi.
1) Spare Parts In general, the maintenance of each system must establish a corresponding spare parts library, mainly to store some equipment that is more important and not easy to repair immediately after damage, such as gun cameras, lenses, and monitors. Once these devices fail, they may cause the system to fail to operate properly and must be replaced in time. Therefore, a certain number of spare parts must be available, and the inventory of the spare parts library must be constantly updated according to the characteristics of the equipment's ability to maintain and operate the equipment.
2) Fittings Fittings are mainly the additional configuration of various discrete components and modules in the equipment, which can be used for equipment maintenance. The commonly used accessories include various integrated circuit chips and various circuit discrete components required for the circuit. Other larger devices must be equipped with certain functional modules for emergency use. In this way, after maintenance, small investments can be made to produce good benefits, saving a lot of money for updating equipment.
3) Tools and Inspection Instruments For the Qi Gun Camera to be used for repairing equipment, it is necessary to configure commonly used maintenance tools and maintenance equipment, such as various pliers, screwdrivers, pencils, soldering irons, tapes, multimeters, oscilloscopes, etc. Should also be added at any time, if necessary, they should also make their own simulation load as a test tool.
2, as follows:
1). Dust removal, cleaning and sweeping of dust from the gun-type camera equipment are performed once a quarter. The gun-type camera, protective cover and other components must be removed and thoroughly dusted. After that, each lens is wiped clean with anhydrous alcohol to adjust the resolution. To prevent the dust from inhaling into the monitoring equipment body due to the operation of the machine, static electricity and other factors, to ensure the normal operation of the machine. At the same time check the monitoring room ventilation, cooling, clean dust, power supply and other facilities. Outdoor temperature should be -20 °C ~ +60 °C, relative humidity should be 10% to 100%; indoor temperature should be controlled at +5 °C ~ +35 °C, relative humidity should be controlled at 10% to 80%, leaving a good monitoring room equipment Operating environment.
2). According to the instructions for the use of each part of the gun camera system, it will check its technical parameters and the quality of the transmission line of the monitoring system every month, handle potential faults, and assist supervisors in setting various data such as usage levels to ensure that each part of the equipment The item is well-functioning and can operate normally.
3). The gun-type camera equipment components that are prone to aging should be thoroughly checked once a month. Once they are found to be aging, they should be promptly replaced and repaired, such as a video head.
4). The vacuuming part is regularly cleaned once a quarter. If the monitor is exposed to the air, due to the electrostatic effect of the screen, many dust will be adsorbed on the surface of the monitor, affecting the clarity of the screen, and the monitor should be wiped regularly. The color and brightness of the monitor.
5). The monitoring equipment that works for a long time is regularly maintained once a month. For example, if the hard disk recorder works for a long time, it will generate more heat. Once the fan has a fault, it will affect the heat discharge, so as to prevent the hard disk recorder from working abnormally.
6). Monitor the operation status of the gun camera system and equipment, analyze the operation status, and find and eliminate faults in time. Such as: network equipment, server systems, monitoring terminals and various terminal peripherals. Check the running of the desktop system and virus defense of the network and desktop systems.
7). Monthly optimization of the gun camera system and equipment is carried out on a regular basis: a reasonable arrangement of monitoring network requirements for the gun camera center, such as bandwidth, IP address and other restrictions. Provide monthly monitoring of network performance of the surveillance system, including network connectivity, stability, and utilization of bandwidth; real-time detection of all external network attacks that may affect monitoring network devices, real-time monitoring of server operating status, traffic, and intrusion monitoring Wait. Check the abnormal situation and perform relevant processing. According to the needs of the user, the planning and optimization of the monitoring network will be carried out; the failure of the server hardware and software and the disassembly and assembly of the relevant hardware and software will be assisted.
8). Monthly periodical information service is provided: on the first working day of the month, the emergency repair, maintenance, maintenance, and maintenance records of the previous month are submitted to the supervisory center of the monitoring center in the form of electronic documents.
Basic function analysis 1. The number of pixels refers to the maximum number of pixels of the gun camera CCD sensor, and some of them give the number of horizontal and vertical pixels, such as 500H × 582V, and some of them give the value of the wait for the first two products, such as 300,000 pixels . For a CCD chip of a certain size, the larger the number of pixels, the smaller the area per pixel unit, and the higher the resolution of a gun camera composed of the chip.
2. The resolution resolution is an important parameter to measure the advantages and disadvantages of the black-and-white gun cameras. It refers to the fact that when the gun camera captures black and white stripes arranged at equal intervals, it can be seen on the monitor (which should be higher than the resolution of the camera). The maximum number of lines, when it exceeds this number of lines, the screen can only see a gray piece and can no longer distinguish the black and white lines.
The resolution test usually uses a gun camera to capture a resolution test card and read the data through a waveform monitor. The specific method is as follows:
(1) Arrange the test environment. Place the resolution test card on the standard test light box, about 3m away from the camera. The video output of the gun camera is connected to a waveform monitor and the output of the waveform monitor is connected to a high resolution black and white monitor.
(2) The illuminance of scenery is set to 2000lx, and the color temperature of the light source is set to 3200K.
(3) Adjust the lens focal length (or select the appropriate fixed-focus lens and move the camera forward or backward slightly) to fill the monitor screen with the image of the resolution card and sharpen the image with precise focus.
(4) Observe the resolution card with the selected oscilloscope to get the waveform.
(5) Adjust the lens aperture so that the signal white level reaches 100% (70mV). At this time, the number of TV lines whose modulation is deeper than 5% is the limit resolution.
3. Minimum Illumination Minimum Illumination is also an important parameter to measure the merits of gun cameras, sometimes omitting the word “lowest†and directly referred to as “illuminanceâ€. The minimum illuminance is a luminosity value of the scene when the illuminance of the subject is low to a certain extent and the level of the video signal output by the gun camera is as low as a predetermined value. When measuring this parameter, the maximum relative aperture of the lens should also be specified. For example, with an F1.2 lens, when the brightness of the subject is as low as 0.04LX, the amplitude of the video signal output by the camera is 50% of the maximum amplitude, ie, 350mV (the maximum amplitude of the standard video signal is 700mV. ), the minimum illumination of this gun camera is called 0.04LUX/F1.2. The brightness value of the subject was low, and the amplitude of the video signal output by the gun camera was less than 350mV. Reflected on the screen of the monitor, it would be a gray image with a hardly distinguishable level.
At present, due to the fact that the market's specifications are not yet uniform, the low illumination characteristics of some gun cameras with low illumination indices may not be as good as the low illumination characteristics of gun cameras with slightly higher illumination indexes. The reason for this is that the standards used for measuring the low-lightness index are different. Still taking the aforementioned example as an example, if the video signal amplitude output by the camera is reduced to 30% of the maximum amplitude (that is, 210 mV) as a reference, the brightness value of the imaged object can be further lowered, such as 0.03LX. If the optical lens is further replaced with an F1.0 lens, the luminous brightness of the subject can be further reduced due to the increase of the luminous flux, such as 0.02LX.
It can be seen from the above analysis that it is impossible to accurately determine which camera has low illuminance characteristics by putting aside the measurement standard and simply comparing the illuminance nominal value of a certain brand of gun camera with the illuminance nominal value of another brand of gun camera. Good conclusions, because the relative aperture of the lens they use and the specified value of the output video signal may not be the same. Therefore, the minimum illumination index can only be used for reference when designing and purchasing equipment.
4. The SNR is also one of the main parameters of the gun camera. When a gun camera captures bright scenes, the screen displayed by the monitor is usually brighter, and observers cannot easily see the interference noise in the screen. When the camera captures a dark scene, the screen displayed by the monitor is darker. At this time, it is easy to see snow-like noise in the picture. The strength of the interference noise (that is, the degree of influence of the interference noise on the picture) is directly related to the quality of the gun-type camera signal-to-noise ratio. That is, the higher the signal-to-noise ratio of the gun camera, the greater the influence of the interference noise on the picture. small.
The so-called "signal-to-noise ratio" refers to the ratio of the signal voltage to the noise voltage, which is usually represented by the symbol S/N. Since in general the signal voltage is much higher than the noise voltage, the ratio is very large. Therefore, the actual calculation of the camera signal-to-noise ratio is usually based on the ratio of the mean squared signal voltage to the mean square noise voltage. The number is multiplied by a factor of 20, that is, the unit of equation (2-3) is expressed in dB.
The signal-to-noise ratio given by the general gun camera is the value when the AGC (automatic gain control) is turned off, because when the AGC is turned on, the small signal is boosted, so that the noise level is also increased accordingly. The typical value of CCD gun camera signal to noise ratio is generally 45dB ~ 55dB. When measuring the SNR parameter, a video clutter measuring instrument should be used to connect directly to the video output terminal of the gun camera.
Gun-type camera features Gun-type camera powerful, widely used, cost-effective, with the following characteristics:
In recent years, with the extensive application of security surveillance cameras, high-definition gun camera imaging technology, high-definition fog function, infrared detection lock, day and night conversion infrared camera functions have been widely used in television monitoring projects. The day and night conversion infrared camera function of the gun-type camera enables the camera to perform filter switching between day and night, detect infrared light, and solve the frequent day and night conversion problem of ordinary day and night cameras. It can effectively reduce image noise in nighttime low illumination environments and improve picture quality. The zoom range of the gun camera depends on the lens you choose, from several times to ten times, and the lens replacement is very convenient. According to the choice of different lenses, to achieve long-distance or wide-angle monitoring, there are many applications. In the use of road monitoring, even if the range of vehicle speed changes is large, the bolt camera can also provide a clear picture. Through the built-in light suppression function, manual electronic shutter settings, to achieve the license plate capture. It can truly reproduce nighttime dynamic scenes, and is suitable for places such as highways, toll stations, and safe cities that are monitored 24 hours a day.
Installation Tips 1. Familiar with product performance The project owner and user should be familiar with the product's technical parameters, such as how much the input voltage is, how big the power is, and what functions it has.
2. Check the hemisphere camera for detection and adjustment before installation so that the camera is in normal working condition.
3. Installation Method Before construction, installation methods such as wall mounting or hoisting may be adopted according to the environment, safety, and aesthetics.
4. Installation Angle The installation angle of the gun camera directly affects the scope of the monitoring image, so the installation needs to be more in accordance with the needs of the field. If installed at the entrance of the cell is less than 6 meters, the camera's angle is recommended to be 30 ° -60 °; if installed in the cash register, the camera's angle should be considered in the ± 15 ° -20 ° and so on. In short, the camera avoids the appearance of backlighting as much as possible, so that it can reach the customer's requirements as much as possible.
5, do a good job of video interface processing camera video signal output port, power input port, control signal port is more important, the installation should be as good as possible waterproof, and anti-oxidation treatment. In order to avoid instability, uncontrolled, or even display images in the future.
Maintenance Tips 1. Maintaining the basic conditions The old saying is good, “A woman is a no-nothing woman,†and the same is true for the maintenance of a gun camera system. The basic maintenance conditions for a normal maintenance of a gun camera system are required. That is to achieve "four Qi", that is, spare parts Qi, accessories Qi, tools Qi, instruments Qi.
1) Spare Parts In general, the maintenance of each system must establish a corresponding spare parts library, mainly to store some equipment that is more important and not easy to repair immediately after damage, such as gun cameras, lenses, and monitors. Once these devices fail, they may cause the system to fail to operate properly and must be replaced in time. Therefore, a certain number of spare parts must be available, and the inventory of the spare parts library must be constantly updated according to the characteristics of the equipment's ability to maintain and operate the equipment.
2) Fittings Fittings are mainly the additional configuration of various discrete components and modules in the equipment, which can be used for equipment maintenance. The commonly used accessories include various integrated circuit chips and various circuit discrete components required for the circuit. Other larger devices must be equipped with certain functional modules for emergency use. In this way, after maintenance, small investments can be made to produce good benefits, saving a lot of money for updating equipment.
3) Tools and Inspection Instruments For the Qi Gun Camera to be used for repairing equipment, it is necessary to configure commonly used maintenance tools and maintenance equipment, such as various pliers, screwdrivers, pencils, soldering irons, tapes, multimeters, oscilloscopes, etc. Should also be added at any time, if necessary, they should also make their own simulation load as a test tool.
2, as follows:
1). Dust removal, cleaning and sweeping of dust from the gun-type camera equipment are performed once a quarter. The gun-type camera, protective cover and other components must be removed and thoroughly dusted. After that, each lens is wiped clean with anhydrous alcohol to adjust the resolution. To prevent the dust from inhaling into the monitoring equipment body due to the operation of the machine, static electricity and other factors, to ensure the normal operation of the machine. At the same time check the monitoring room ventilation, cooling, clean dust, power supply and other facilities. Outdoor temperature should be -20 °C ~ +60 °C, relative humidity should be 10% to 100%; indoor temperature should be controlled at +5 °C ~ +35 °C, relative humidity should be controlled at 10% to 80%, leaving a good monitoring room equipment Operating environment.
2). According to the instructions for the use of each part of the gun camera system, it will check its technical parameters and the quality of the transmission line of the monitoring system every month, handle potential faults, and assist supervisors in setting various data such as usage levels to ensure that each part of the equipment The item is well-functioning and can operate normally.
3). The gun-type camera equipment components that are prone to aging should be thoroughly checked once a month. Once they are found to be aging, they should be promptly replaced and repaired, such as a video head.
4). The vacuuming part is regularly cleaned once a quarter. If the monitor is exposed to the air, due to the electrostatic effect of the screen, many dust will be adsorbed on the surface of the monitor, affecting the clarity of the screen, and the monitor should be wiped regularly. The color and brightness of the monitor.
5). The monitoring equipment that works for a long time is regularly maintained once a month. For example, if the hard disk recorder works for a long time, it will generate more heat. Once the fan has a fault, it will affect the heat discharge, so as to prevent the hard disk recorder from working abnormally.
6). Monitor the operation status of the gun camera system and equipment, analyze the operation status, and find and eliminate faults in time. Such as: network equipment, server systems, monitoring terminals and various terminal peripherals. Check the running of the desktop system and virus defense of the network and desktop systems.
7). Monthly optimization of the gun camera system and equipment is carried out on a regular basis: a reasonable arrangement of monitoring network requirements for the gun camera center, such as bandwidth, IP address and other restrictions. Provide monthly monitoring of network performance of the surveillance system, including network connectivity, stability, and utilization of bandwidth; real-time detection of all external network attacks that may affect monitoring network devices, real-time monitoring of server operating status, traffic, and intrusion monitoring Wait. Check the abnormal situation and perform relevant processing. According to the needs of the user, the planning and optimization of the monitoring network will be carried out; the failure of the server hardware and software and the disassembly and assembly of the relevant hardware and software will be assisted.
8). Monthly periodical information service is provided: on the first working day of the month, the emergency repair, maintenance, maintenance, and maintenance records of the previous month are submitted to the supervisory center of the monitoring center in the form of electronic documents.