Patent: Improvements for Dual Pixel AF

Canon Rumors Guy

EOS 1D MK II
Jul 20, 2010
7,534
289
Canada
www.canonrumors.com
HTML:
It looks like the next version of Dual Pixel AF is being developed according to the <a href="http://pdfaiw.uspto.gov/.aiw?PageNum=0&docid=20180047768">latest patent on the subject</a>.</p>
<p><strong><a href="https://www.canonnews.com/canon-patent-application-dual-pixel-sensor-improvements">Canon News</a> notes:</strong></p>
<blockquote><p>This patent goes heavily into the “methods of manufacturing” the improvement, detailing layer by layer how the image sensor is fabricated.  There’s a good chance that this is one in which Canon is attempting to seriously do.</p></blockquote>
<p>It’s obvious Canon will continue to improve Dual Pixel AF in both manufacturing and performance.</p>
<span id="pty_trigger"></span>
 

Mt Spokane Photography

I post too Much on Here!!
Mar 25, 2011
15,307
569
Skimming thru it is difficult. The patent, naturally tries to cover not only the current design, but many alternate designs, including quad pixel and more. Its a window into the alternate designs being considered for the next stage to replace the current dual pixel design, and likely contains some red herrings to confuse competitors. With other manufacturers now producing split pixel designs, staking out Canon's process for producing them is a good idea.

My other thought is that the process of producing a dual pixel sensor is very difficult, that has been mentioned in interviews with Canon. Its more expensive to produce one, so roll out has been slow.
 

Bahrd

Red herrings...
Jun 30, 2013
22
3
Canon Rumors said:
It’s obvious Canon will continue to improve Dual Pixel AF in both manufacturing and performance.</p>
<span id="pty_trigger"></span>[/html]
I wonder what prevents Canon from intertwining vertically and horizontally oriented Dual Pixels.
 

Sharlin

EOS 6D MK II
Dec 26, 2015
820
199
Turku, Finland
Bahrd said:
Canon Rumors said:
It’s obvious Canon will continue to improve Dual Pixel AF in both manufacturing and performance.</p>
<span id="pty_trigger"></span>[/html]
I wonder what prevents Canon from intertwining vertically and horizontally oriented Dual Pixels.
I'm pretty sure it's massively easier to fab a sensor where every photosite is identical than one where every other is differently oriented.
 

Mt Spokane Photography

I post too Much on Here!!
Mar 25, 2011
15,307
569
Sharlin said:
Bahrd said:
Canon Rumors said:
It’s obvious Canon will continue to improve Dual Pixel AF in both manufacturing and performance.</p>
<span id="pty_trigger"></span>[/q][/q][/q]


I wonder what prevents Canon from intertwining vertically and horizontally oriented Dual Pixels.
I'm pretty sure it's massively easier to fab a sensor where every photosite is identical than one where every other is differently oriented.


I think they are at least looking at splitting pixels into a block of 4. This would allow for vertical or horizontal AF, but it also is less efficient because the surface area of the sub pixels is less than one large pixel using the same space would be. Still, we may see 4 way pixels if there is a benefit worth the cost and effort.
 

Cochese

EOS T7i
Oct 22, 2014
95
46
Mt Spokane Photography said:
Sharlin said:
Bahrd said:
Canon Rumors said:
It’s obvious Canon will continue to improve Dual Pixel AF in both manufacturing and performance.</p>
<span id="pty_trigger"></span>[/q][/q][/q]


I wonder what prevents Canon from intertwining vertically and horizontally oriented Dual Pixels.


I'm pretty sure it's massively easier to fab a sensor where every photosite is identical than one where every other is differently oriented.


I think they are at least looking at splitting pixels into a block of 4. This would allow for vertical or horizontal AF, but it also is less efficient because the surface area of the sub pixels is less than one large pixel using the same space would be. Still, we may see 4 way pixels if there is a benefit worth the cost and effort.
Depending on how much control they have over each sub pixel, it's possible they could also use each photosite to record a certain amount of light, similar to the current hack, that allows for a gain in DR. Only this would happen all in body. Two sub pixels could under expose and two over expose while the main image is an average of all four.
 

canonnews

EOS RP
Dec 27, 2017
235
132
Canada
www.canonnews.com
Mt Spokane Photography said:
Skimming thru it is difficult.
Tell me about it. ;)

I toss out 90% of the sensor patents because they are just so hard to take down to normal human language.

Mt Spokane Photography said:
My other thought is that the process of producing a dual pixel sensor is very difficult, that has been mentioned in interviews with Canon. Its more expensive to produce one, so roll out has been slow.
I honestly believe the difficulty that Canon had at the beginning because because of new fab / design rules. Before the DPAF sensors, canon was able to get away with 500nm design rules, with Dual Pixel that was basically an impossibility.

So canon most likely had to upgrade equipment on the fly to do much smaller design rules that DPAF required. Thus the additional cost and the reduced yield at the start.

I would imagine that with Canon now up to full frame DPAF sensors, so basically doing all from 1" to full frame, they have the process under control.
 

canonnews

EOS RP
Dec 27, 2017
235
132
Canada
www.canonnews.com
Sharlin said:
Bahrd said:
Canon Rumors said:
It’s obvious Canon will continue to improve Dual Pixel AF in both manufacturing and performance.</p>
<span id="pty_trigger"></span>[/html]
I wonder what prevents Canon from intertwining vertically and horizontally oriented Dual Pixels.
I'm pretty sure it's massively easier to fab a sensor where every photosite is identical than one where every other is differently oriented.
it's really just different exposure masks. doesn't make much difference really. those things are relatively "cheap", from what I recall in the low thousands for each layer.
 

3dit0r

EOS M50
Dec 4, 2017
46
6
I wonder if Canon's focus is more on this aspect of sensor design, or on organic sensor/global shutter design. Perhaps the two are not mutually exclusive, of course, but I just had in mind Panasonic's announcement last week, and Sony's follow up. Particularly Panasonic's organic global shutter sensor sounded impressive, at least superficially.

DPAF is great, though. Does anyone more technically minded know if this patent would indicate any DPAF improvements which would mean Eye-AF (à la Sony) would be possible? That would be a killer combo.