Patent: Canon sensor tilt to offset image plane changes

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Here’s a patent that has been misinterpreted on a few websites out there, but Canon News has translated the patent correctly for us. This patent is being interpreted as IBIS (in body image stabilization) when it is in fact related to tilting the sensor to offset changes in the image plane.
Canon News breaks down Japan Patent Application  2018-194766:
This patent application describes cases when zooming a lens, the image plane “tilts” and shifts.  This patent is so that when you are zooming the lens, the sensor will automatically tilt in two axis, depending on instructions from the lens itself.
We have yet to see a detailed IBIS patent from Canon, though we reported yesterday that IBIS will be coming to a future Canon EOS R series camera.

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why would image plane *tilt* when a [decent] zoom lens is zoomed? All lens elements and groups are moving strictly axially along optical axis, no?

I interpret the patent as a possible way to get (some degree of) "tilt" (and maybe also shift) effects without T/S lenses, by moving sensor.
Obviously the image plane tilts when you tilt the camera, which is something that happens during handheld photography. Sensor tilting on two axes would be required for 5-axis image stabilization.
BTW -- two translational and one rotational stabilization elements could be done digitally with a little crop, but two rotational and one translational elements must be done with sensor movement.
 
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This sounds like another application for a RF lens with its ability to exchange more information with a camera.

The patent is certainly not IBIS, and I have to congratulate Canon News for making sense out of it.


"[Detailed Description of the Invention]
[Field of the Invention]
[0001]
The present invention relates to the lens device which communicates between camera bodies."


Although its certainly not IBIS, it might be possible to use a IBIS motor to make it work. That might be yet a different patent.

"[Means for solving problem]
[0013]
In order to achieve the above-mentioned object, the optical instrument concerning the present invention, and its system, A camera device provided with the control means which carries out the tilt of the image sensor to an optic axis, It consists of a lens device provided with the detection means which detects the parameter to which the image formation performance of a lens is changed, The image sensor according to a parameter falls from the aforementioned lens device, information is transmitted to the aforementioned camera device, and it is characterized by comprising the optical instrument which consists of the camera device in which the thing [ falling and carrying out the tilt of the image sensor to an optic axis based on information ] is possible, and its system."

The lens will have a ROM Memory which contains correction information based on zoom and focus position and even position of a IS image group, a potentially huge amount of data which must be reduced to something manageable.

"[0025]
ROM7 is rewritable nonvolatile memory (memory means). The data memorized by nonvolatile ROM7 is the information which mainly shows the optical characteristic peculiar to the interchangeable lens 1, and a camera obtains this information from the interchangeable lens 1, and is correcting by photographing elements falling further based on this information. In the present invention, the information memorized by nonvolatile ROM7 is described as optical correction information. Two or more kinds of information is consisted of by this optical correction information, and there are mainly piece blur quantity of an interchangeable lens, direction (azimuth) information, etc. the piece of the lens from which the data memorized by nonvolatile ROM7 changes with the parameters to which the image formation performance of a lens is changed -- a blur -- they are direction (azimuth) and a size. Specifically, it is the information by the lens position of a focusing unit. As for these, it is preferable to memorize data also including the information by zoom arrangement as two-dimensional information on zoom arrangement and a focusing unit position.
[0026]
Since two dimensional data is needed according to the parameter which image formation performance changes as optical correction information was mentioned above, the data volume will become very immense. Therefore, optical correction information is a range which can obtain desired optical performance, and was thinned out and held to necessary minimum, and the method of carrying out interpolation formation from the approaching data is taken in the photographing parameter in the meantime.
[0027]
When there is furthermore a vibration control lens unit, it is preferable to memorize data as three-dimensional information also including the information on an eccentric state of a vibration control lens unit."

As far as what is in the camera body, its pretty vague, the main thrust of the patent is how a lens will detect and transmit data to a camera body.

"[0045]
Here, specific photographing elements fall and it describes about a Method of amendment. an image sensor can be attached to the unit which can be driven to biaxial [ of alpha rotation and beta rotation ] as shown in Fig.3 -- the piece blur quantity of the interchangeable lens of the interchangeable lens 1 (lens device) -- it responded for being suitable (azimuth) -- it falls and can correct. The drive unit of these image sensors is not limited to an embodiment, but various deformation and change within the scope of the summary are possible for it."



Then, at the very end, I see this??

"0052]
The present invention is applicable to video equipment, such as a camera with interchangeable lenses and video.."

I envision this to be something used with a 8K broadcast lens with a extreme zoom range as used for sporting events. However, such lenses are typically used with Sony Video cameras, so unless they have the matching image sensor drivers, it would be of little use. I think its one of those ideas looking for additional development.
 
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Back swings and tilts are usually done to maintain parrallel lines and prevent geometric distortion and convergence. I suppose there might be enough variation when a zoom lens goes from wide to telephoto to justify tilting the back plane but you've got me on this one.

edit: I was writing this while MSP was posting so I didn't get to read his post first. A superzooming broadcast camera pointed downward to capture an event might benefit from a sensor that could correct geometric distortion on the fly. Theoretically video shot with a tilted backplane might appear to be shot from a level position rather than from overhead although the players might look a little odd. Interesting.
 
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Back swings and tilts are usually done to maintain parrallel lines and prevent geometric distortion and convergence. I suppose there might be enough variation when a zoom lens goes from wide to telephoto to justify tilting the back plane but you've got me on this one.
From what I read in the patent, the need for the sensor adjustment to correct for lens distortions is mote apparent with the high MP sensors where even a tiny error is apparent.
 
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RunAndGun

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Makes sense. I think you may be right. Sounds like high end 8K broadcast gear. Error correction rather than visual effect. I wonder if Canon intends to market broadcast cameras? I'd imagine it's very profitable.

Not as much as you'd think(a lot of it is prestige and marketing. And back-in-the-day tech would trickle down to the consumer level whereas today we see a lot of ideas/tech at the consumer level first, then it's adapted to the pro market). Even though most broadcast gear is expensive(at least at the scope/scale of a normal/sane person), it's a lot more expensive to manufacture vs. consumer gear and things like R&D costs are harder to recoupe, because you're only selling a few handfuls of copies in comparison to a piece of consumer gear.
 
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