Canon Patent: RF 28-70mm f/2.8L That Does Not Extend, Inner Focusing

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Here is a very interesting Canon patent application, once more for an RF mount lens. An RF 28-70mm f/2.8L with inner focusing and that does not extend might be in the works.

The Canon patent application spotted by asobinet.com (they did not disclose the patent number), discusses optical formulas for a RF 28-70mm f/2.8L lens. The interesting part, if I got it right from the machine translated Japanese text, is that the lens not only does all the focusing but also employs a design that is usually found on wide-angle lenses.

It sounds like a patent for a small and lightweight standard zoom. The characteristic of this optical system is that the total length is the longest at the wide-angle end and the total length becomes shorter toward the telephoto end. This is a common optical system for wide-angle lenses, but I don’t see this type of lens with standard zoom lenses, especially with large-aperture zoom lenses. If it is really put into practical use, it will be a very portable lens.

Did I get it right? The lens is indeed described to be shorter at the telephoto end (emphasis mine) in both embodiment:

  • Wide-angle intermediate telephoto
  • Focal length 28.84 36.81 67.90
  • F number 2.91 2.91 2.91
  • Half angle of view (°) 32.68 29.23 17.67
  • Image height 18.50 20.60 21.64
  • Lens total length 117.09 109.31 101.58
  • BF 9.99 13.47 21.59
  • Focal length 28.84 37.17 67.90
  • F number 2.91 2.91 2.91
  • Half angle of view (°) 32.65 28.90 17.67
  • Image height 21.64 21.64 21.64
  • Lens total length 132.62 122.81 111.18
  • BF 21.92 26.79 39.84

Moreover, the lens uses a floating focus structure to achieve autofocus. That means it might have very fast and and highly responsive AF. The patent literature is very clear in what should be achieved:

PROBLEM TO BE SOLVED: To provide a zoom lens having a short overall lens length, being compact and lightweight, and having high optical performance.

All comments welcome.

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

Canon Patent: RF 180mm f/3.5 Macro And RF 200mm f/4 Macro

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And here is a new Canon patent application and as most of them are, this one too is for RF-mount lenses.

asobinet.com spotted Canon patent application 2021-152568 (Japan). The patent application discusses optical formulas for both RF 180mm f/3.5 Macro and RF 200mm f/4 Macro lenses. The former lens might replace the EF 180mm F3.5L Macro USM, a lens that has already been discontinued.

PROBLEM TO BE SOLVED: To provide an optical system which is suitable for a macro lens and can suppress aberration fluctuation.

The optical system of each embodiment has an aperture aperture SP2 as a main focus aperture that determines (limits) the light beam of the open F number (Fno), and a positive refractive power arranged on the object side of the aperture aperture SP2. It has a front focus group LPF, a rear focus group LPR having a positive refractive power arranged on the image side of the aperture aperture SP2, and a negative refractive power arranged on the image side of the rear focus group LPR. It has a posterior group LN. The “group” as used herein means each group of lenses whose spacing changes during focusing.

Embodiment 1:

  • Focal length 171.00
  • F number 3.50
  • Half angle of view (°) 7.21
  • Image height 21.64
  • Overall length of optical system 194.49
  • BF 47.67
  • Magnification ∞ β = -1

Embodiment 2:

  • Focal length 174.43
  • F number 3.50
  • Half angle of view (°) 7.07
  • Image height 21.64
  • Overall length of optical system 189.49
  • BF 13.73
  • Magnification ∞ β = -1

Embodiment 3:

  • Focal length 140.00
  • F number 3.50
  • Half angle of view (°) 8.78
  • Image height 21.64
  • Overall length of optical system 177.49
  • BF 35.17
  • Magnification ∞ β = -1

Embodiment 4:

  • Focal length 194.00
  • F number 4.00
  • Half angle of view (°) 6.36
  • Image height 21.64
  • Overall length of optical system 202.49
  • BF 39.36
  • Magnification ∞ β = -1

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

Canon Patent: RF 16-30mm f/4-5.6 Lens For The EOR System

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Here is another Canon patent application for an RF-mount lens, as usual spotted by asobinet.com.

Canon patent application 2021-148949 (Japan) discusses optical formulas for what seems to be a RF 16-30mm f/4-5.6 lens for the EOS R full frame mirrorless system. From the patent literature:

PROBLEM TO BE SOLVED: To provide a small and wide angle-of-view zoom lens having high optical performance in the entire zoom range, and an image pickup device and an image pickup system having the same.

[…] In recent years, a zoom lens used in an imaging device is required to have high optical performance in the entire zoom range, to be compact and to have a wide angle of view, as the imaging device becomes more sophisticated. As a zoom lens that is small and relatively easy to widen, a negative lead type zoom lens in which a lens group having a negative refractive power precedes (is located closest to the object side) is known. As a negative lead type zoom lens, Patent Document 1 discloses a zoom lens composed of first to fourth lens groups having negative, positive, negative, and positive refractive powers arranged in order from the object side to the image side. ing. Further, Patent Document 2 discloses a zoom lens composed of first to fifth lens groups having negative, positive, positive, negative, and positive refractive powers arranged in order from the object side to the image side.

If it hits the market, this is going to be an affordable lens for the EOS R system, like the recently released RF 16mm f/2.8 STM pancake lens.

Embodiment 1:

  • Zoom ratio 1.79
  • Wide-angle intermediate telephoto
  • Focal length 16.48 22.05 29.50
  • F number 4.12 4.79 5.61
  • Half angle of view (degrees) 55.80 44.90 35.80
  • Image height 21.64 21.64 21.64
  • Lens total length 100.88 99.27 100.51
  • BF 14.00 16.25 19.80

Embodiment 2:

  • Zoom ratio 1.79
  • Wide-angle intermediate telephoto
  • Focal length 16.48 22.05 29.50
  • F number 4.12 4.12 4.12
  • Half angle of view (degrees) 55.20 45.00 36.20
  • Image height 21.64 21.64 21.64
  • Lens total length 110.07 105.92 108.00
  • BF 12.80 17.50 21.37

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

Canon Might Be Working On A Better Battery Charge Indicator, Patent

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Will this Canon patent come to your next Canon camera? Maybe not, but it might on the one after your next.

Canon patent application 2021-114887 discusses methods and technology to show charges of both the internal and external battery. From the patent literature:

[Problem]

To notify a user of a relation between a full charge capacity of a battery of an electronic device and a remaining amount of a battery of a battery device connected to an electronic device easily.

[Means for solving]

The battery device (100) has a display means for displaying information indicating a result of calculating a residual amount of a battery of the battery device based on a full charge capacity of a battery of an electronic device connected to the battery device.

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

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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 Patent: Automatic Shutter Mode Switch (mechanical/electronic)

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And yet another very interesting Canon patent application spotted by asobinet.com. What about your camera switching automatically the shutter mode?

Canon patent application 2021-129230 discusses technology and methods to automatically switch from mechanical shutter to electronic shutter based on parameters. From the patent literature:

PROBLEM TO BE SOLVED: To provide a lens device, an image pickup device, a camera system, and a program capable of taking an image with an optimum shutter method without a user manually changing a setting.
Conventionally, an imaging device that realizes imaging by using a mechanical shutter and an electronic shutter in combination has been proposed. In Patent Document 1, flicker detection is performed based on a signal output from an image sensor, and based on the result, imaging is selected to select whether to use a mechanical shutter or an electronic shutter in the second and subsequent imaging of continuous imaging. The device is disclosed. When flicker occurs, the image pickup apparatus of Patent Document 1 uses an electronic shutter to improve the efficiency of the image pickup operation, thereby improving the frame speed during continuous shooting.
However, the shooting conditions in which it is preferable to use a mechanical shutter or an electronic shutter depend on requirements other than the frame speed. For example, when imaging is performed at a shutter speed at which the effect of rolling shutter distortion is large, it is desirable to use a mechanical shutter. Further, when imaging is performed at a shutter speed in which the shutter impact is sustained during the imaging period, it is desirable to use an electronic shutter in order to suppress image blurring. On the other hand, there are some users who like the sound and shooting sensation when using the mechanical shutter.
An object of the present invention is to provide a lens device, an image pickup device, a camera system, and a program capable of taking an image with an optimum shutter method without manually changing a setting by a user.

If I got it right the shutter switch is triggered by shutter speed and also by the tracked shooting distance:

The lens device is a lens device which can be mounted on an imaging device which picks up an image of a subject and an imaging device which has a mechanical shutter. A determination unit is provided with a determination unit which determines which of the mechanical shutter and the electronic shutter is to be used for starting imaging of an imaging device using information on an imaging device and information on a current imaging condition, and notifies the imaging device of a determination result.

Interesting fact: there is another Canon patent that discusses how to automatically silence the shutter based on subject and distance.

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