# Patent: Another stacked CMOS sensor patent



## Canon Rumors Guy (Sep 7, 2020)

> Canon News uncovered another in-depth patent for a stacked CMOS sensor. This is an area that Canon has been spending considerable R&D resources on over the last few years, but we have yet to see a product for the masses come from this investment.
> According to Canon News, this patent looks at ways to reduce the costs associated with stacked sensors. In this case, they’re attempting to lower the costs of adding bypass capacitors into the sensor.
> 
> Recently, a solid-state imaging device has been proposed that by stacking a plurality of semiconductor components. The solid-state imaging device described in Patent Document 1 includes a plurality of stacked components, the first component is provided with a pixel portion, and the second component is provided with a read-out portion for reading out a signal from the pixel portion. .. In addition to the first component and the second component...



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## navastronia (Sep 8, 2020)

Let's see a stacked CMOS make it into the R1


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## jolyonralph (Sep 8, 2020)

I think a stacked CMOS for the R1 is pretty much essential if the R1 wants to match/beat the Sony A9 II (and possibly III by that point) in electronic shutter performance.


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## Joules (Sep 8, 2020)

jolyonralph said:


> I think a stacked CMOS for the R1 is pretty much essential if the R1 wants to match/beat the Sony A9 II (and possibly III by that point) in electronic shutter performance.


Have you seen any comparisons between the A9 II and R5 with regard to stills electronic shutter read out speed? I could not find a proper test yet. 

As far as I know, the R5 is a huge step forward in this regard. So I am not sure if the difference in read out speed is all that significant between the A9 II and R5 when considering the resolution difference.


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## jolyonralph (Sep 8, 2020)

Joules said:


> Have you seen any comparisons between the A9 II and R5 with regard to stills electronic shutter read out speed? I could not find a proper test yet.
> 
> As far as I know, the R5 is a huge step forward in this regard. So I am not sure if the difference in read out speed is all that significant between the A9 II and R5 when considering the resolution difference.



The R5 still has the same limitations for rolling shutter that the 1DXIII has (which of course is the same as the R6 sensor) - see this to show the big difference between rolling shutter on the A9 and the 1DX III

See this: Go to about 1min into the video for the most dramatic difference:






So yes, the A9/A9 II sensor still works better than this.


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## Joules (Sep 8, 2020)

jolyonralph said:


> The R5 still has the same limitations for rolling shutter that the 1DXIII has (which of course is the same as the R6 sensor) - see this to show the big difference between rolling shutter on the A9 and the 1DX III
> 
> See this: Go to about 1min into the video for the most dramatic difference:
> 
> ...


Well that's the question. Is the R5 slower than the 1DX III in terms of readout? I got the impression that is not the case. But I can't find any direct comparison between R6/1DX III or A9 I/II and the R5 right now.


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## Mark3794 (Sep 8, 2020)

Joules said:


> Well that's the question. Is the R5 slower than the 1DX III in terms of readout? I got the impression that is not the case. But I can't find any direct comparison between R6/1DX III or A9 I/II and the R5 right now.


The R5 is actually a bit faster than the R6 despite the higher mp count


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## caffetin (Sep 8, 2020)

I don't get it. Can someone explain pros, cons of such sensor?


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## bbb34 (Sep 8, 2020)

caffetin said:


> I don't get it. Can someone explain pros, cons of such sensor?



Chip stacking is a way to increase the ratio of photosensitive area of the pixels to the overall area of the sensor. This is also known as "fill factor". A higher fill factor contributes to the sensitivity of the sensor, because more light can be collected, and less light is lost in-between the pixels.

Current camera sensors are mainly CMOS ICs with active pixels. Active means, there are switches and amplifiers that are needed to operate and readout the photo diodes. All this active circuit is made of transistors, and all transistors occupy chip area that is not available for photo diodes. The higher the pixel density, the worse is the impact of this circuitry on the fill factor.

Now with this quick and rough introduction, stacking means that the manufacturer fabricates a sandwich of two chips. The upper one contains mostly the photo diodes, and the lower one contains mostly other circuitry. This maximizes the fill factor on the upper photosensitive chip. It improves light sensitivity and the (in)famous DR (dynamic range).

Disadvantages: lack of maturity, development cost, fabrication cost, impact on fabrication yield (which adds onto cost).


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## caffetin (Sep 8, 2020)

bbb34 said:


> Chip stacking is a way to increase the ratio of photosensitive area of the pixels to the overall area of the sensor. This is also known as "fill factor". A higher fill factor contributes to the sensitivity of the sensor, because more light can be collected, and less light is lost in-between the pixels.
> 
> Current camera sensors are mainly CMOS ICs with active pixels. Active means, there are switches and amplifiers that are needed to operate and readout the photo diodes. All this is made of transistors, and all transistors occupy chip area that is not available for photo diodes. The higher the pixel density, the worse is the impact of this circuitry on the fill factor.
> 
> ...


Ty.


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## [email protected] (Sep 8, 2020)

On the R5 vs 1d3 question, I can say the R5 is better. I had both with me last week. I think it was a discussion on this board, although it might have been on a different one: I couldn't make it do much in the way of rolling shutter in my efforts. 

A site I contribute to has an R5 review like everyone else, and they did rolling shutter tests. A boy on a bike and a running dog looked fine, but the real test was a flying helicopter's rotors, and it looked great on the R5. You can see the picture of it if you go here... https://camnostic.com/r5-3/
... and scroll down to the "Major Capabilities..." section and click on the "Jello" tab. You'll see the rotors are pretty straight.

Until a month ago, I owned and shot the Sony A9II, and after a few thousand frames with the R5, I think they're about the same; which is to say, you don't think/worry about it while shooting them.


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