According to a certain resolution, the points on the image are acquired by interlaced scanning. When scanning to a certain point, the gray level of the image at the point is converted into a voltage value corresponding to the gray level by the image sensing chip. This voltage value is then output through the video signal terminal. When the in-vehicle camera continuously scans one line on the image, the output is a continuous voltage signal, and the fluctuation of the voltage signal reflects the gray level change of the image of the line. When a line is scanned, the video signal terminal outputs a level lower than the lowest video signal voltage (eg, 0.3V) for a period of time. This is equivalent to a voltage "groove" immediately after each line of image signals. This "groove" is called a line sync pulse, which is a mark for scanning a line feed. Then, after skipping one line (because the car camera is interlaced), start scanning a new line, and so on, until the video signal of the field is scanned, and then a field blanking area will appear. There are several composite blanking pulses in this region, one of which is much wider (i.e., longer than) other blanking pulses, called field sync pulses, which is a sign of the scan transition. The field sync pulse marks the arrival of a new one. However, the field blanking area just crosses the end of the previous field and the beginning of the next field. The field blanking area is past, and the next video signal is true. arrival. The car camera scans 25 images per second, each of which is divided into odd and even two fields. The odd field is followed by the field, so 50 images are scanned every second. In the odd field, only the odd lines in the image are scanned, and in the even field, only the even lines are scanned.
Effective pixels and resolution. The resolution is actually the number of sync pulses per field, because the more the number of line sync pulses, the more rows are scanned for each field of image. In fact, the resolution reflects the longitudinal resolution of the on-board camera. The effective pixels are often written in the form of two-digit multiplication, such as "320x240", where the former value represents the fineness of the single-line video signal, that is, the line resolution capability; the latter value is the resolution, and thus the effective pixel = line resolution capability & TImes; resolution .
Car camera classification:The camera is divided into black and white and color. In order to achieve the purpose of hunt, it is only necessary to extract the gray information of the picture without having to extract its color information, so the black and white camera is used in this design. This reduces the burden of microcontroller sampling compared to color car cameras with the same resolution. The camera is mainly composed of a lens, an image sensing chip and peripheral circuits. The image sensor chip is the most important part, but the chip must be equipped with appropriate peripheral circuits to work. The chip and peripheral circuits are fabricated on a single board, called a "single board." If the board is equipped with a lens, a casing, a lead and a connector, it constitutes a commonly seen camera, such as a camera for chatting; if only the lens is attached to the board, this is a "single camera". Single-board cameras are rare in everyday life, and companies that produce veneers usually sell them to other companies, and other companies package the boards at their own discretion.
Car camera purchase method:The first trick: ask the sensor chip, which is the chip solution for the camera.
Photosensitive chips on the general market can be divided into two types: CCD (charge coupled) and CMOS (metal oxide). The former has the advantages of good imaging level, high definition and high color reduction coefficient, and is often used in high-end digital code cameras and digital cameras. The disadvantage is that the price is relatively expensive, the power consumption is large, and the chip volume is large. The latter's shortcomings are exactly the same as the former, the price is relatively low, the power consumption is also small, and the chip size is also small. With the rapid development of CMOS technology, the performance of CMOS images is getting better and better, some have super CCD effects during the day, and even some high-end professional cameras now use CMOS sensors. CCD sensors are slightly better than CMOS sensors in terms of sensitivity, resolution, and noise control, while CMOS sensors are characterized by low cost, low power consumption, and high integration. However, with the advancement of CCD and CMOS sensor technology, the difference between the two is very small. Therefore, when selecting a camera, do not demand whether the camera uses a CCD image sensor. And now some CMOS cameras also add image light source automatic gain enhancement, automatic brightness adjustment, white balance control, saturation contrast automatic adjustment and other image control technology, which can fully match the CCD camera.
360° Protection - Ultra-thick, yet lightweight soft lining and cushioning inside with water resistant material outside offers your device 360° protection from everything from zipper scratch to knocks, bumps.
Compartment - Main side-mounted pocket with silk access to your laptop, and two sealed pockets to easily store and transport your accessories such as Kindle, charger, adapter, mouse, cables, phone, wallet, etc. You can always find what you want when you need it.
Convenient Carrying - Thick pad, fully-adjustable detachable shoulder strap and top PU leather handle provide maximum comfort and perfect fit for everybody.
The productive process :
Make the Products Mould –Cutting the fabric –Do the half products – Finish products – Cleaning –QC- Package – Shippment .
Laptop Bag,Tablet Case Cover,Leather Laptop Bag,Leather Tablet Case Cover
Guangzhou Ysure Electronic Technology Co., Ltd. , https://www.ysurecase.com