Science popularization: the relationship between stack type and back illuminated CMOS | Love computer - 上海419贵族宝贝-上海后花园1314-上海品茶网-阿拉爱上海

Published some time ago Nubia Z5 And OPPO Find 5 In terms of hardware parameters, they are very similar. They also use a 1080P screen, Qualcomm's 8064 quad core processor, and a 13 million pixel camera. However, in terms of media publicity, OPPO said that they use 13 million pixels Stacked The CMOS sensor, while Nubia only said that their lens is the back reflection type, so many people think that the Find 5 lens is better than the Z5 lens. But in fact, the stack type and the back reflection type are two different things, maybe they are the same lens. What is the relationship between stack style and backlight style? Please see the following details.

Backlit sensor

The photodiode of the traditional surface illumination camera sensor is located at the lowest layer of the entire chip, while the A/D converter and amplification circuit are located at the upper layer of the photodiode, so the photodiode is farther away from the lens, and the line connection layer at the upper layer will also cause reflection of light, affect the light intensity reaching the photodiode, resulting in a reduction of the amount of light received by COMS.

The backlight sensor places these line connection layers that block light from entering behind the photodiode, so that the photosensitivity of COMS will be greatly improved, especially in low light environment.

Stacked sensor

In the figure below, we can see that the stack sensor is to place the signal processing circuit in the original ordinary sensor on the original support substrate, so that more pixels can be placed in the space vacated, and more pixels can be gathered on the small sensor. Since the pixel part and the circuit part are independent. Therefore, the pixel part can be optimized for high image quality, and the circuit part can be optimized for high performance.

From the above introduction, we can see that the stack type and the backlight type are two different things. The backlight type can be simply regarded as changing the position of the photodiode, while the stack type is changing the position of the signal circuit. A COMS can be both back lit and stack lit. We can say that stack CMOS originates from back illuminated CMOS and is higher than pure back illuminated CMOS.

Although Nubia does not claim that the Z5 lens is also a stack type sensor, we also know from some internal information that the Z5 is actually a stack type sensor. So simply from the hardware point of view, there is no difference between the two. We don't know why Z5 doesn't promote its camera as a stack. Maybe it wants to learn from Apple, or maybe it's because Find 5 has already taken the lead.

In addition, although the lenses of the two mobile phones may be exactly the same, the quality of the mobile phone's photography is also related to the manufacturer's debugging of the lens in addition to the hardware configuration, so even the effects of the same lens may vary greatly. If you want to know which of these two phones has better photo taking effect, you can follow us Love to play computer games The upcoming evaluation.