CMOS sensor beyond CCD this is nothing new, but there are a lot of friends do not know, why CMOS will be so popular, it is said that these two sensors like a fierce rival general, often said one of them, the other inevitably will be taken out. Moreover, SONY stopped making CCD chips in March 2017, which is enough to show that CMOS works well in use.
Here Xuan Zhan technology to SONY auto focus camera FCB-EV7520 as an example, the details of the two chips to do a detailed comparison, to help the majority of users to further understand CMOS:
① It used to be thought that CMOS chips were much less efficient at converting incident light, but this is no longer the case. Today’s CMOS chips can achieve the same or even better sensitivity than CCD chips thanks to improvements in the array of microlenses on the chip.
② Thanks to its architecture, CMOS chips can achieve higher frame rates. Combining the improved sensitivity with the latest global shutter technology from CMOSIS, Sony and ON Semiconductor, such chips can now shoot very fast image sequences. This in turn can improve the performance of your app, such as checking more parts per second or providing clearer images. CMOS chips typically have higher full well capacity (also known as saturation capacity). The full well capacity is the maximum number of electrons per pixel, and the ratio between the full well capacity and the sensitivity threshold determines the dynamic range that the chip can cover. So although the CCD chip provides a better sensitivity threshold, the CMOS chip, through its superior saturation capacity, not only makes up for its disadvantage in dynamic performance, but also surpasses the former. In this way, the dynamic level performance of CMOS and CCD chips is almost equal. The Sony IMX174 chip is a case in point: it offers superior dynamic range compared to all comparable CCD chips.
③ Although it may have been reasonable a few years ago to say that CCD chips had better performance in low light (although CMOS chips were slightly ahead in bright light), the imaging quality of CMOS chips has improved greatly in recent times, and they are now well adapted to low light conditions.
④ Their advantages in bright light conditions also remain. When a CCD pixel is overexposed, extra electrons can “splash” onto neighboring pixels. This creates an effect called “halo” : very bright structures in the image expand into the dark. When the charge on the CCD chip is transmitted after exposure in very bright light situations, the CCD chip sometimes produces bright bars in the image. These white areas are part of an effect called “tailgating”, and are perhaps most obvious when a car is driving at night with its headlights on and facing the camera-neither of which happens on CMOS chips.
⑤ The new generation of cameras with CMOS chips will even have a global shutter function, such as our ace camera models with Sony’s “Pregius” chip series, ON Semiconductor’s “PYTHON” and CMOSIS’s “CMV”. This means that artifacts that occur in rolling shutter cameras will no longer be possible.
SONY auto focus camera FCB-EV7520, using SONY’s new Exmor R CMOS sensor, effective pixel 2.13 million, equipped with 30 times optical zoom lens, with high-definition shooting mode, the new defog function and wide dynamic greatly improve the clarity of the picture, while with high highlight suppression function, Solve the problem of car lights too bright at night, and can reach the star level of low illumination function, even in very weak low light can clearly present the object.
FCB-EV7520 with USB3.0 interface board