Canon Patent: Quad Pixel Dual Cross Autofocus

Drawing From The Patent Literature
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For once a Canon patent application that is not for an RF mount lens. It’s for what could be a future generation of autofocus.

Canon patent application 2022-2383 (Japan) discusses methods and technology for a Quad Pixel Dual Cross autofocus system which one day might well be featured on a Canon mirrorless camera.

PROBLEM TO BE SOLVED: To increase the division direction of a pupil region while suppressing variation in sensitivity of an image signal.

As one of the focus detection methods of an image pickup device, a so-called image pickup surface phase difference method, in which a pupil division signal is acquired by using a focus detection pixel formed in an image pickup device and focus detection is performed by a phase difference method, is used. Are known. As a focus detection pixel, a configuration in which one microlens and a plurality of sensitivity regions are formed in each pixel is known, and each of the plurality of sensitivity regions is light that has passed through different pupil regions of the photographing optical system. The pupil division signal can be acquired by receiving light.

The patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Automatic Adjustment Of Touchpad AF Sensitivity

Canon Patent Application
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Interesting Canon patent application spotted by asobinet.com. The sensitivity of the touchpad used for autofocus tracking is automatically adjusted with regard to shutter speed and the subject.

Canon patent application 2021-128242 discusses technology and methods to automatically set the touchpad sensitivity when tracking a subject with autofocus.

If we got this patent right, the sensitivity of the touchpad is based on subject recognition technology and values computed from the shutter speed and the movement speed of the subject. In other words: if the algorithm detects a fast moving subject and a fast shutter is set, then the sensitivity of the touchpad is increased in the sense that the AF frame will move faster when the touchpad is used to track a subject. Here is the machine translated patent abstract:

Problem: To improve the operability of an AF frame.

Means for solving: A touch detection means capable of detecting touch operation on a touch panel, and a display control means for displaying an item showing an in-focus position on a display part ; A shutter speed acquiring means for acquiring a shutter speed being set and a control means for moving the item on the display part in accordance with the amount of movement of the touch position detected by the touch detecting means, and the control means is used when the touch position detected by the touch detecting means is a 1 movement amount. It has a control means controlled so that a direction when the aforementioned shutter speed is larger than the above-mentioned first value moves the aforementioned item largely rather than the case where the aforementioned shutter speed is smaller than a first value.

And, in particular:

[…] In the method [described in the patent, editor’s note] when the user is chasing a fast-moving subject, if the AF frame is set small, the touch move must be performed many times in order to move the AF frame [and hence the subject tracking might fail, editor’s note] Therefore, the AF frame cannot be moved according to the speed of movement of the user, which may reduce the operability of the user.

Do you think I got the patent right? Feel free to speak out in the comments section.

More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Patent: Improved Image Plane Phase Difference AF Using IBIS Data

Canon Patent
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Another Canon patent application spotted by asobinet.com: how to improve the detection of image plane phase difference autofocus by using data derived from IBIS (In Body Image Stabilisation).

Canon patent application 2021-128303 discusses technology and methods to improve phase difference AF on a subject represented by a horizontal line.

[Problem]

To provide an imaging device capable of detecting focus even if a subject is a horizontal line pattern.


[Means for solving]

An imaging element for picking up an image for detecting a phase difference in a predetermined direction on an image plane to detect a focus state of an image formed by an imaging lens, and an imaging element driving means for driving the imaging element in a translational direction and a rotational direction in a plane perpendicular to an optical axis of the imaging lens ; What it has for a focus detection means which is made to rotate the aforementioned image sensor by the aforementioned image sensor driving means according to the imaging result by the aforementioned image sensor, and carries out focus detection was considered as the composition by which it is characterized.

More from the patent literature:

Conventionally, as AF of the phase difference detection method, secondary imaging phase difference AF using a secondary imaging optical system and an AF sensor, or image plane phase difference AF using an image sensor is known. .. In the secondary imaging phase difference AF, the AF sensor is composed of a vertical eye sensor that forms a vertically separated subject image and a horizontal eye sensor that forms a horizontally separated subject image. Focus detection of vertical line patterns is possible.


However, in the image plane phase difference AF, when each pixel of the image sensor is composed of a pixel group divided in only one direction, the focus of the horizontal line pattern or vertical line pattern is detected depending on the division direction of the pixels. May not be possible . In a general image pickup device capable of image plane phase difference AF, since the pixels are divided into two in the left-right direction, it is difficult to detect the focus on the horizontal line at the normal position of the image pickup device.


The conventional technique disclosed in Patent Document 1 described above solves the problem that the image plane phase difference AF of the image pickup device in which each pixel is divided in only one direction cannot detect the focus of a subject having a horizontal line pattern.

Basically, the discussed technology makes it easier to detect lines that are difficult to detect with image plane phase detection AF.

More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these:

Canon Got Autofocus Right Already 40 Years Ago (with the FD 35-70mm ƒ/4 AF)

FD 35-70mm
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Nowadays for most photographers it is not imaginable to have a lens without autofocus. Hasn’t always been that way. See how Canon managed to make an awesome AF lens not less than 40 years ago: the FD 35-70mm ƒ/4 AF.

The Canon FD 35-70mm ƒ/4 AF was released in May 1981. Here are the specifications:

Lens Construction (group)8
Lens Construction (element)8
No. of Diaphragm Blades6
Minimum Aperture22
Closest Focusing Distance (m)0.5
Maximum Magnification (x)0.15
Filter Diameter (mm)52
Maximum Diameter x Length (mm)85 x 99.5
Weight (g)604
FD 35-70mm

That’s how Canon described the lens in 1981:

This is the world’s first autofocus zoom lens with an autofocus function using Canon’s own SST (Solid State Triangulation) method. The incorporation of this function into the best-selling FD35-70mm f/4 (June 1979) interchangeable lens brought about automation of focusing for SLR cameras.

The SST method is a system in which information on the photographed object that enters the sensor through two fixed mirrors is converted into an electric signal and distance is measured by a microcomputer, with focusing performed by moving a distance ring with a motor. The latest fixed imaging device CCD (charge-coupled device) technology is adopted to provide high resolution and a broad dynamic range able to detect low to high luminance, making it less susceptible to the contrast and pattern size of the photographed object and enabling highly precise autofocusing. Also, as the SST method does not have a movable section in the distance measuring mechanism, no vibration or electric noise is caused, which provides high reliability fitting of a high-end SLR camera.

Kai W has a look at and introduces the Canon FD 35-70mm ƒ/4 AF lens in the video below.

More information about the Canon FD 35-70mm ƒ/4 AF may be found here.

Image courtesy photo.net

[via DPReview]

Canon Patent For Eye-Controlled Focus For Mirrorless Cameras

Eye-controlled Focus
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A technology already seen on Canon film cameras might come to last generation mirrorless camera technology, sooner or later.

Canon patent application US20210051265 (USA) discusses how to implement eye-controlled focus on a mirrorless camera.

An image capture apparatus detects a subject in a captured image. The image capture apparatus further recognizes its user based on an eyeball image of the user. The image capture apparatus then selects a main subject area from among the detected subject areas, based on information regarding subjects captured in the past and stored being associated with the recognized user.

There is a significant difference if compared with the eye-controlled focus technology used inn the old days for film cameras. The patent discusses some sort of intelligent algorithm that not only recognizes the user but also remembers where the user looked and how frequently.

We think the technology discussed in the patent might get into production within the next years. More Canon patents are listed here. Some particularly interesting patent applications we think might get into production are these:

Source: Canon Rumors

Canon Patent: Quad Pixel Autofocus Imaging Sensor

Quad Pixel
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Dual Pixel AF was true innovation when first launched by Canon on the EOS 70D. It’s just common sense to assume Canon will develop it further. Welcome Quad Pixel AF.

Here is a Canon patent for a Quad Pixel AF imaging sensor, and it is not the first we spotted. Canon patent application 2020-171060 (Japan) discusses the technology. It’s hard to say when we will see the first commercial Quad Pixel AF sensor. But we know it is coming.

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these: