What is the car camera
At present, the car camera has become the most important sensor in the car to some extent. Whether it is the pure vision route that Tesla believes in or the multi-sensor fusion scheme that is widely used in the industry, the vehicle camera is an indispensable part of it.
The rapid development of intelligent vehicles has also led to the increase in the number of vehicle camera applications, and its market scale has also increased accordingly. According to relevant data, the global car camera market size will reach 27 billion dollars in 2025, and China’s car camera industry is expected to reach 23 billion yuan.
Depending on the installation location, the car camera can be divided into front view camera, look around camera, rear view camera, side view camera and built-in camera. At present, the camera is mainly used for reversing image (rear view) and 360 degree panorama (look around) in the car.
In order to overcome the blind area and achieve full coverage of blind area vision, the number of cameras for cars will be more than 4; Up to 8 cameras can be equipped for various auxiliary equipment of cars with smart cabin; Used to assist the driver in parking or trigger emergency braking; The number of cameras configured for cars with ADAS system can reach 6; A camera with automatic driving function shall have more than 22 cameras to support the data collection of driving environment.
Car camera function
1. Provide reliable evidence for the analysis and judgment of traffic accidents.
2. It is convenient for drivers and passengers to check the conditions in the car.
3. Provide basis for handling disputes among passengers in the vehicle, finding lost objects, anti-theft and other issues.
4. Provide monitoring of the internal and external environment of the compartment to provide safety guarantee for vehicle driving.
What kind of car camera is good
1. Chip
CCD and CMOS chips are important components of reversing camera, which can be divided into CCD and CMOS according to different components.
CMOS is mainly used in products with low image quality. Its advantages are that its manufacturing cost and power consumption are lower than those of CCD. Its disadvantages are that CMOS cameras have higher requirements for light sources;
CCD is a high-end technical component used in photography and video recording, which is also attached with a video capture card.
There is a big gap between CCD and CMOS in technology and performance. Generally speaking, CCD has a better effect, but the price 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 to measure the camera. Generally speaking, the image quality of products with high definition will be better. The products with 420 lines of definition have become the mainstream products of reversing cameras. The 380 lines can also be selected if they are debugged well. There are also better 480 lines, 600 lines and 700 lines of chips.
However, depending on the chip level of each camera and the different sensitive components, including the level of the debugging technician, the quality effect of products with the same chip and the same level may be different. In addition, it depends on the quality of the lens used. The image presentation effect will be much better if the lens is made of good materials. On the contrary, the night vision effect of products with high definition will be discounted.
3. Night vision
The night vision effect is related to the product’s definition. The higher the definition, the worse the night vision effect. This is due to the chip itself. However, good quality products have night vision functions and do not image objects. Although the color is poor, the clarity is not a problem. If there is infrared night vision fill light or LED white light fill light, night vision will be more clearly visible.
4. Waterproofing
The reversing camera products are basically waterproof
5. Special reversing camera for special vehicles
Many cars have produced special reversing cameras that can be used with more than 500 models. When selecting, you must first select the special reversing camera for your own model, if not, then select the general reversing camera.
6. Universal camera
General cameras include 18.5mm hole punched camera, small butterfly external camera, license plate frame camera, 28mm hole punched camera, bus camera and other external cameras, such as the LED night vision color external camera of the vehicle navigator.
Four key parameters
As the core component, the lens of the car camera has four key parameters as follows:
1. Focus of on-board camera
The size of the focal length determines the size of the field angle. The focal length value is small, the field angle is large, and the observation range is large, but the object at a long distance is not very clear; The focal length is large, the field angle is small, and the observation range is small. As long as the focal length is appropriate, even objects far away can be seen clearly. Since the focal length and the angle of view are one-to-one, a certain focal length means a certain angle of view, so when selecting the focal length of the lens, you should fully consider whether the observation details are important or whether a large observation range is important. If you want to see the details, you should choose a long focal length lens; If you want to watch a big scene at close range, choose a wide-angle lens with a small focal length.
2. Aperture coefficient of on-board camera
That is, light flux, expressed in F, measured by the ratio of lens focal length f and luminous aperture D. Each lens is marked with the maximum F value. For example, 6mm/F1.4 means the maximum aperture is 4.29mm. The luminous flux is inversely proportional to the square of the F value. 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 rule is that the exposure amount of the previous scale is exactly twice the exposure amount corresponding to the next one. That is to say, the luminous aperture of the lens is 1/1.4, 1/2, 1/2.8, 1/4, 1/5.6, 1/8, 1/11, 1/16, and 1/22, respectively. The former value is twice the root of the latter value. Therefore, the smaller the aperture index, the larger the luminous aperture, and the greater the illuminance on the imaging target surface. In addition, the aperture of the lens can be divided into manual IRIS and automatic IRIS. It is used with the camera. The manual aperture is suitable for situations where the brightness changes little. Its light input is adjusted through the aperture ring on the lens until it is appropriate at one time. The automatic aperture lens will automatically adjust with the change of light, and is used for outdoor, entrance and other occasions where the light changes greatly and frequently.
3. Auto iris lens of on-board camera
At present, automatic aperture lenses are divided into two types: one is called VIDEO drive type, and the lens itself contains an amplifier circuit to convert the VIDEO amplitude signal from the camera into the control of the aperture motor. The other type is called DC drive type, which uses the DC voltage on the camera to directly control the aperture. This lens only contains a galvanometer diaphragm motor, which requires an amplifier circuit in the camera. For all kinds of automatic aperture lenses, there are usually two adjustable knobs. One is ALC adjustment (metering adjustment). There are two options: peak metering and average metering according to the target luminous conditions. Generally, average metering is taken; The other is LEVEL adjustment (sensitivity), which can make the output image bright or dim.
4. Zoom lens of on-board camera
The zoom lens is divided into manual zoom lens and automatic zoom lens. The manual zoom lens is generally used in scientific research projects rather than in the closed-circuit monitoring system. When monitoring large scenes, cameras are usually used with electric lenses and PTZ. The advantage of the electric lens is that it has a wide zoom range. You can not only see a wide range of situations, but also focus on a certain detail. In addition, the PTZ can rotate up, down, left and right, so the viewing range is very large. The electric lens has multiple magnification such as 6 times, 10 times, 15 times, and 20 times. If you know the reference focal length again, you can determine the variable range of the lens focal length. For example, if a 6x electric lens has a reference focal length of 8.5 mm, its zoom range is 8.5 to 51 mm continuously adjustable, and the field angle is 31.3 to 5.5 degrees. The control voltage of the electric lens is generally DC 8V~16V, and the maximum current is 30mA. Therefore, the length of transmission cable shall be fully considered when selecting the controller. If the distance is too far, the voltage drop generated by the line will cause the lens to be uncontrollable. The input control voltage must be increased or the video matrix host must be replaced to cooperate with the decoder for control.
In addition to the above four items, of course, there are other details, but mastering these four index coefficients can make the lens suitable for configuration and application.
Working principle of on-board camera
The camera power supply is connected to the reversing tail lamp. When the reverse gear is engaged, the camera synchronized power supply enters the working state. The collected video information is sent to the wireless receiver at the front of the vehicle through the wireless transmitter. The receiver transmits the video information to the GPS navigator through the AV IN interface. In this way, when the receiver receives the signal, whether the Gps navigator is in any kind of operation interface, They will give priority to the LCD screen for reversing video.
Installation requirements for on-board camera
With the rapid development of automotive electronic technology and security technology, the vehicle camera has become an indispensable hardware for traffic safety.
Next, we will introduce the installation skills and troubleshooting of vehicle mounted products.
- The working temperature of the on-board camera on the market is between 0-50 degrees, because it is in the car, and the temperature requirement is higher than that of the ordinary monitoring host. The on-board camera mainly monitors the working status of drivers and attendants, and sudden time monitoring, which provides good evidence for traffic accidents and functions as a black box for cars.
- Cameras on the market generally have two kinds of storage devices, an ordinary computer hard disk and an SD card. The SD card is characterized by good shock resistance but small storage space of only about 8 hours, and high maintenance costs. The ordinary hard disk can support 300 g and can record video for one month.
- In fact, in addition to the monitoring function, the on-board camera also has the functions of multimedia playback, speed, license plate number, speed superposition, driver data superposition and gps/gprs and wireless transmission.
- There are certain requirements for the installation of the on-board camera because of the particularity of its installation. It needs to be small in size and light in installation, which can not affect the passenger’s riding environment, and it needs to be fixed easily. As a result, the monitoring effect is affected. It has a little seismic resistance. The most important thing is that there must be an infrared lamp, which is convenient for monitoring when the light is bad. It is recommended that you use small hemisphere and conch type cameras with built-in infrared lights.
- The installation cost of a bus mainly includes the following: host cost, camera cost, hard disk, wire rod, installation cost. The price of different host equipment is different, and the number and price of different cameras are also different. The host price in the market is quite different.
Founded in 2015, Shenzhen Jinshikang Technology Co., Ltd. specializes in providing various camera module products such as monocular and binocular cameras. After years of development, it has accumulated profound experience in video capture, video intelligent analysis, and vehicle electronic technology. It has independently developed various differentiated camera modules such as object recognition, face recognition, iris recognition, and is widely used in new retail, face recognition, intelligent monitoring, industrial applications, and various image schemes. JSK is a high-tech enterprise integrating R&D, production, sales and service. Its products are sold at home and abroad and become the designated supplier of many listed companies. Relevant module products can be customized and developed according to the actual requirements of customers. Welcome camera module manufacturers and partners to visit our company and discuss cooperation.