Canon Patent: Eye Control Autofocus For Mirrorless Cameras

Canon Patent

A new Canon patent application about eye controlled autofocus. Two patent applications, to be precise.

Cannon patent application 20220247904 (US) refers to a bigger sized mirrorless camera (like the EOS R3) and Canon patent application 20220247933 (US) to a smaller one. Here is the abstract for the former patent application:

And the abstract for the latter patent application:

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

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Canon Patent: RF 16-28mm Lens That Might Be f/2.8 or f/2.8-4 or f/4

Canon Patent

Here is a Canon patent application for a lens that might hit the shelves, sooner or later: RF 16-28mm.

Canon patent application 2022112179 (Japan) discusses optical formulas for an RF 16-28mm lens. Three optical formulas are discussed in the patent literature:

  • RF 16-28mm f/2.8
  • RF 16-28mm f/2.8-4
  • RF 16-28mm f/4

From the patent literature:

A zoom lens that is compact and has a wide angle of view while achieving high optical performance with little variation in aberration during zooming, and an imaging device and an imaging system having the zoom lens.

A photographing lens with a half angle of view exceeding 35 degrees is called a wide-angle lens, and is suitable for photographing a vast landscape by taking advantage of the wide angle of view. A wide-angle lens needs to satisfactorily correct distortion and curvature of field, which worsen as the half angle of view increases.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a zoom lens which is compact and has a wide angle of view, and which can obtain high optical performance with little aberration fluctuation during zooming, and an image pickup apparatus having the zoom lens.

Example 1

  • Focal length: 16.45-27.50
  • F-value: 2.88
  • Half angle of view: 52.70-39.08
  • Image height: 19.00-21.64
  • Total length: 138.01-127.30
  • Back focus: 14.00

Example 2

  • Focal length: 16.45-27.50
  • F-value: 2.88-4.00
  • Half angle of view: 52.740-38.91
  • Image height: 19.00-21.64
  • Overall length: 121.56-117.50
  • Back focus: 14.21

Example 3

  • Focal length: 16.45-27.50
  • F-value: 4.10
  • Half angle of view: 52.69-39.09
  • Image height: 19.00-21.64
  • Overall length: 124.60-121.49
  • Back focus: 14.08

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

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Canon Patent: RF 150-600mm f/8-11 Zoom Lens For EOS R System

Canon Patent

A new Canon patent, for a RF 150-600mm f/8-11 zoom lens.

Canon patent application 2022106401 (Japan) discusses optical formulas for a 150-600mm f/8-11 zoom lens for the RF mount.

PROBLEM TO BE SOLVED: To provide a compact and lightweight zoom lens having high optical performance in the entire zoom range.

Example 1

  • Focal length: 103.00-387.89
  • F value: 5.82-8.24
  • Half angle of view: 11.86-3.19
  • Image height: 21.64
  • Overall length: 183.21-258.38
  • Back focus: 39.88-81.93

Example 2

  • Focal length: 153.00-581.90
  • F value: 8.00-11.31
  • Half angle of view: 8.05-2.13
  • Image height: 21.64
  • Overall length: 274.81-354.89
  • Back focus: 68.40-126.51

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

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Canon Patent To Improve AF In Lenses With Reflective Optics

Canon Patent

A new Canon patent was spotted. Autofocus improvement for mirror lenses, i.e. lenses with a reflective optical system.

Canon patent application 2022103610 (Japan) discusses methods and technologies to improve autofocus on mirror lenses.

PROBLEM TO BE SOLVED: To provide a lens device capable of detecting an accurate defocus amount when a reflective optical system is used.

However, in the configurations disclosed in Patent Documents 1 and 2, when the central portion of the light flux is shielded by the reflective telephoto lens (catadioptric system), the image signal corresponds to the change in the vignetting direction of the AF light flux. The correction and the calculation of the conversion coefficient are not performed, and a focus detection error occurs.

Therefore, it is an object of the present invention to provide a lens device, an image pickup device, a control method of the lens device, and a program capable of detecting an accurate defocus amount when a reflective optical system is used.

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

[via asobinet]

Canon Patent: Super Small 28-70mm f/2.8 & 28-60mm f/2.8 Lenses For RF Mount

Canon Patent

A new and rather interesting Canon patent application. Very compact zoom lenses with large aperture.

Canon patent application 2022091621 (Japan) discusses optical formulas for two small and compact zoom lenses with large aperture:

  • 28-70mm f/2.8
  • 28-60mm f/2.8

From the patent literature:

PROBLEM TO BE SOLVED: To provide a zoom lens having a short total length and a small size but having high optical performance, and an image pickup apparatus having the same.

In recent years, with the increasing functionality of image pickup devices, there is a demand for a compact and lightweight zoom lens having a large aperture ratio. As a zoom lens that satisfies this requirement, a negative lead type zoom lens in which a lens group having a negative refractive power is arranged on the object side is known (see Patent Document 1 and Patent Document 2).

In the zoom lens of Patent Document 1, the refractive power of the first lens group is strengthened, and the movement locus of the first lens group during zooming becomes a substantially reciprocating locus, so that the total length of the zoom lens at the telephoto end can be increased. become longer. In addition, the back focus is long, and it is difficult to shorten the total length of the zoom lens. Further, the thickness of the first lens group becomes large due to the aberration correction in the first lens group, which is not preferable from the viewpoint of miniaturization and weight reduction.

In the zoom lens of Patent Document 2, the refractive power of the first lens group is strong in order to obtain a zoom magnification, and the configuration of the subsequent group is a four-group configuration up to the fourth lens group. If a larger aperture ratio is aimed at, it will not be possible to suppress various aberrations and zoom fluctuations of aberrations in the telephoto region, and it will be difficult to satisfy good optical performance over the entire zoom range.

An object of the present invention is to provide a zoom lens having a short overall length, a small size, and high optical performance, and an image pickup apparatus having the same.

In the zoom lens of each embodiment, in order to ensure good optical performance even at a close object distance, two or more lens groups among the lens groups arranged on the image side of the first lens group L1 are focused. It is preferable to have a so-called floating configuration in which the lens moves at the time.

Example 1

  • Focal length: 28.84-67.90
  • F value: 2.91
  • Half angle of view: 32.68-17.67
  • Image height: 18.50-21.64
  • Overall length: 138.40-105.42
  • Back focus: 10.97-21.12

Example 2

  • Focal length: 28.84-60
  • F value: 2.91
  • Half angle of view: 32.68-19.83
  • Image height: 18.50-21.64
  • Overall length: 132.38-106.85
  • Back focus: 13.47-23.82

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

[via asobinet]

Canon Patent: 135mm f/2, 400mm f/4 and 50mm f/2.5 With Defocus Smoothing

Defocus Smoothing

Very interesting Canon patent application: a set of RF mount lenses with electronically controlled Defocus Smoothing (DS).

Defocus Smoothing is a technology Canon first introduced with the RF 85mm f/1.2L DS lens (see here for our coverage). The featured Canon patent might suggest more DS lenses are on their way.

Canon patent application 2020-199390 (Japan) discusses optical formulas and methods for three prime lenses with DS:

  • 135mm f/2
  • 400mm f/4
  • 50mm f/2.5

From the patent literature:

PROBLEM TO BE SOLVED: To provide an optical device capable of sufficiently adjusting the clarity of the outline of a blur even if the aperture diameter of a diaphragm is greatly changed.

BACKGROUND ART: Conventionally, an image formed by an optical device may be required to include a blur with a smooth outline, or may include a blur with a clear outline. May be required.

Patent Document 1 discloses an optical device capable of smoothing or clarifying the outline of blur by providing an optical element capable of reversibly switching the distribution of transmittance. The clarity of the outline of the blur is required to be sufficiently adjustable even when the aperture diameter of the diaphragm is greatly changed.

However, the optical device disclosed in Patent Document 1 is insufficient to meet the above-mentioned requirements because the clarity of the outline of the blur can be sufficiently adjusted only in the vicinity of the opening of the aperture.
Therefore, an object of the present invention is to provide an optical device capable of sufficiently adjusting the clarity of the outline of a blur even if the aperture diameter of the diaphragm is greatly changed. In various optical systems such as photographic and video lenses, not only the characteristics of the image plane but also the image quality of the out-of-focus portion, that is, the quality of blur may be emphasized.

In general, there are cases where a smooth blur that melts without a clear outline is desired, and there are cases where a blur with a clear outline is desired. As a method of changing the contour of the blur, for example, a method of inserting an apodization filter whose transmittance decreases as the distance from the optical axis increases is known.

As a result, the transmittance distribution of the apodization filter is superimposed on the blurred image, and smooth blurring such that the contour melts can be realized. However, when the apodization filter is inserted, the outline of the blur is always smooth in the vicinity of the opening of the aperture, so that it becomes difficult to clarify the outline of the blur according to the request.

Further, when the apodization filter is inserted, the amount of transmitted light in the optical system is reduced, so that the demerit of inserting the apodization filter becomes greater in the shooting scene where almost no blurring occurs in the screen.
Therefore, there is also known a method of switching the apodization effect on and off by using an optical element capable of reversibly controlling the distribution of the transmittance, that is, adjusting the clarity of the outline of the blur according to a request.

Example 1

  • Focal length: 133.05
  • F value: 2.06
  • Half angle of view: 9.24
  • Image height: 21.64
  • Overall length: 170.39
  • Back focus: 45.96

Example 2

  • Focal length: 399.84
  • F value: 4.00
  • Half angle of view: 3.10
  • Image height: 21.64
  • Overall length: 298.46
  • Back focus: 145.16

Example 3

  • Focal length: 49.00
  • F value: 2.50
  • Half angle of view: 23.82
  • Image height: 21.64
  • Overall length: 68.15
  • Back focus: 11.00

The following, short video tells what Defocus Smoothing is:

[via asobinet]