1 . Provide reliable evidence for the analysis and judgment of traffic accidents .
2 . Convenient for drivers and passengers to check the condition inside the car .
3 . Provide a basis for handling disputes lost and found items theft prevention and other issues among passengers in the vehicle .
4 . Provide monitoring of the inside and outside environment of the carriage to ensure the safety of vehicle operation .
What kind of car camera is good ? The performance of car mounted cameras can be evaluated from the following aspects :
1 、 Chips
CCD and CMOS chips are important components of the reverse camera which can be divided into CCD and CMOS according to their different components CMOS is mainly used in products with lower image qualit Its advantages are lower manufacturing cost and power consumption compared to CCD but its disadvantage is that CMOS cameras have higher requirements for light sources CCD is a high - end technology component used in photography and videography which also comes with a video capture card CCD and CMOS have a significant difference in technology and performance Generally speaking CCD has better performance but it is also more expensive It is recommended to choose a CCD camera without considering the cost
2 、 Clarity
Clarity is one of the important indicators for measuring cameras Generally speaking products with high clarity will have better image quality Products with a clarity of 420 lines have become the mainstream product for reverse cameras while products with a clarity of 380 lines can also be chosen if well tuned There are better chips such as 480 wire 600 wire 700 wire etc However depending on the chip level of each camera the level of photosensitive components including the level of debugging technicians products of the same chip and grade may present different quality effects It also depends on what kind of lens is used and lenses made of good materials will have much better image presentation effects On the contrary products with high clarity will have some discounts on night vision effects
3 、 Night vision
The night vision effect is related to the clarity of the product The higher the clarity the worse the night vision effect of the product This is because of the chip itself However high - quality products have night vision function and do not produce image effects on objects Although the color may be slightly different clarity is not a problem If there is infrared night vision fill or LED white light fill night vision will be clearer and more visible
4 、 Waterproofing
Most reverse camera products have waterproof function
To sum up , when choosing a reverse camera , we should consider the above aspects , and the most important thing is to see and compare the actual effect of the image .
5 、 Dedicated reversing camera for special vehicles
Many cars have already produced specialized reverse cameras that can be used with over 500 models . When choosing , be sure to first choose your own model specific reverse camera . If not , then choose a universal reverse camera .
6 、 Universal camera .
General purpose cameras include 18.5mm perforated cameras small butterfly external cameras license plate frame cameras 28mm perforated cameras bus cameras and other external cameras such as LED night vision color external cameras for car navigators
The lens of the car mounted camera is the core component , and the four key parameters are as follows :
focal length
The size of the focal length determines the size of the field of view angle . When the focal length value is small , the field of view angle is large , and the observed range is also large , but the resolution of distant objects is not very clear ; The focal length value is large , the field of view angle is small , and the observation range is small . As long as the focal length is selected appropriately , even distant objects can be seen clearly . Due to the one - to - one correspondence between focal length and field of view angle , a determined focal length means a determined field of view angle . Therefore , when selecting a lens focal length , it is important to fully consider whether the observation details are important or whether a large observation range is important . If you want to see details , choose a long focal length lens ; If you are watching close - up scenes , choose a wide - angle lens with a small focal length .
Aperture coefficient
The light flux , represented by F , is measured by the ratio of the lens focal length f to the aperture D. Each lens is labeled with a maximum F value , for example , 6mm / F1.4 represents a maximum aperture of 4.29 millimeters . The luminous flux is inversely proportional to the square of the F - value , and the smaller the F - value , the greater the luminous flux . The scale values of the aperture index sequence on the lens are 1.4 , 2 , 2.8 , 4 , 5.6 , 8 , 11 , 16 , 22 , etc . The pattern is that the exposure amount at the previous scale value is exactly twice that of the corresponding exposure amount at the latter scale value . That is to say , the aperture of the lens is 1 / 1.4 , 1 / 2 , 1 / 2.8 , 1 / 4 , 1 / 5.6 , 1 / 8 , 1 / 11 , 1 / 16 , 1 / 22 , respectively . The former value is twice the root of the latter value . Therefore , the smaller the aperture index , the larger the aperture , and the greater the illumination on the imaging target surface . In addition , the aperture of the lens can be divided into manual IRIS and automatic IRIS . When used in conjunction with a camera , manual aperture is suitable for situations where there is not much change in brightness . Its light intake is adjusted through the aperture ring on the lens until it is suitable in one go . The automatic aperture lens will automatically adjust according to the changes in light , and is used in outdoor , entrance and other places with large and frequent light changes .
Auto iris lens
Automatic aperture lenses are divided into two categories : one is called video (VIDEO) drive type and the lens itself contains an amplifier circuit to convert the video amplitude signal transmitted by the camera into control of the aperture motor . Another type is called DC drive type which uses the DC voltage on the camera to directly control the aperture . This type of lens only includes an ammeter type aperture motor and requires an amplifier circuit inside the camera . For various types of automatic aperture lenses , there are usually two adjustable knobs . One is the ALC adjustment (metering adjustment) , which has two options : peak metering and average metering based on target lighting conditions . Generally , the average metering level is taken ; Another is LEVEL adjustment (sensitivity) , which can make the output image bright or dim .
Zoom lens
There are two types of zoom lenses : manual zoom lenses and electric zoom lenses . Manual zoom lenses are generally used for scientific research projects rather than in closed - loop monitoring systems . When monitoring large scenes , the camera usually needs to be used in conjunction with an electric lens and pan tilt . The advantage of an electric lens is that it has a large zoom range , which allows for viewing a wide range of situations and focusing on certain details . In addition , the pan tilt can rotate up , down , left , and right , resulting in a very large viewing range . Electric lenses have multiple magnifications such as 6x , 10x , 15x , 20x , etc . If you know the reference focal length , you can determine the variable range of the lens focal length . For example , a 6x electric lens with a reference focal length of 8.5 millimeters would have a continuously adjustable zoom range of 8.5 to 51 millimeters and a field of view angle of 31.3 to 5.5 degrees . The control voltage of electric lenses is generally 8V ~ 16V DC , with a maximum current of 30mA . So when selecting a controller , it is important to fully consider the length of the transmission cable . If the distance is too far , the voltage drop generated by the line will cause the lens to be uncontrollable . Therefore , it is necessary to increase the input control voltage or replace the video matrix host with a decoder for control .
The camera power is connected to the reverse taillights . When reverse gear is engaged , the camera synchronizes power supply and enters the working state . The collected video information is sent to the wireless receiver located at the front of the car through the wireless transmitter . The receiver transmits the video information to the GPS navigator through the AV IN interface . This way , when the receiver receives the signal , regardless of whether the Gps navigator is in any operating interface , the LCD screen will be given priority for reverse image video .
The difference between the use of car mounted cameras , car mounted displays , and car mounted DVD navigation systems , as well as portable GPS navigation systems , is that when using car mounted displays , the car mounted displays do not need to be turned on . As long as reverse gear is engaged , the car mounted displays will automatically display the image of the car mounted camera ; The car DVD navigation can only display the car camera image under normal startup conditions ; When using a portable GPS navigation system , it is necessary to turn on the navigation system before displaying the car camera image
In today's rapidly developing automotive electronics and security technology , in car cameras have become indispensable hardware for traffic safety .
Next , we will introduce the installation techniques and troubleshooting of car products .
1 . The working temperature of car mounted cameras on the market is between 0 - 50 degrees Celsius . The reason is that they are located inside the car , and the temperature requirements are higher than those of ordinary monitoring hosts . The main function of car mounted cameras is to monitor the working status of drivers and crew members , as well as to monitor unexpected times , providing good evidence for traffic accidents and serving as a black box for cars .
2 . There are generally two types of storage devices for cameras on the market , a regular computer hard drive and an SD card . The SD card is characterized by good seismic resistance but small storage space of only about 8 hours , and high maintenance costs . A regular hard drive can support 300g and can record videos for a month .
In fact , in addition to monitoring functions , the onboard camera also has multimedia playback , vehicle speed , license plate number , speed overlay , driver information overlay , as well as GPS / GPRS and wireless transmission functions .
4 . Due to its special installation , there are certain requirements for the installation of the car mounted camera . It needs to be small in size , lightweight , and not affect the passenger's riding environment . It also needs to be easy to fix , which can affect the monitoring effect . It has some seismic resistance , and most importantly , it must have infrared lights to facilitate monitoring in poor lighting conditions . I suggest using small hemispheres with built - in infrared lights and conch shaped cameras .
5 . Because the industry of in car cameras has just started , customers initially did not have high requirements for this color , and the price of color was also relatively expensive . However , with the development of technology , color cameras will also become more and more widespread .
The installation cost of a bus mainly includes the following aspects : host cost , camera cost , hard drive , wiring , installation cost . The price of different host equipment varies , and the price of different camera quantities also varies . The host price in the market itself varies greatly .
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