Canon Patent: RF 100-300mm f/2.8L IS USM Lens

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A new Canon patent application was spotted.

Canon patent application 2023099388 (Japan, published 7/13/2023) discusses optical formulas for what appears to be an RF 100-300mm f/2.8L IS USM lens for the EOS R camera system. From the patent literature:

Title of Invention

A zoom lens, an imaging device having the same, and an imaging system.

An object of the present invention is to provide a lightweight zoom lens that has high optical performance over the entire zoom range, and an imaging device and an imaging system having the zoom lens.

Description of the Related Art

In recent years, zoom lenses used in imaging apparatuses are required to have high optical performance over the entire zoom range and to be lightweight. In order to meet these requirements, the zoom lens has a first lens group with positive refractive power, a second lens group with negative refractive power, and a subsequent group including a plurality of lens groups, arranged in order from the object side to the image side. Lenses have been proposed (see Patent Documents 1 and 2).

A large-aperture telephoto zoom lens having a long focal length and a small F-number tends to have a large lens diameter, which tends to cause an increase in weight. In order to reduce the weight of the zoom lens, it is effective to increase the positive refractive power of the first lens group and reduce the lens diameters of the lens groups included in the subsequent group. However, if the refractive power of the first lens group is made too strong, it becomes difficult to correct spherical aberration, axial chromatic aberration, and lateral chromatic aberration, especially at the telephoto end.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a lightweight zoom lens that has high optical performance over the entire zoom range, and an imaging apparatus and imaging system having the zoom lens. Focusing is performed by moving the fifth lens unit L5 and the sixth lens unit L6 along different trajectories . Specifically, the fifth lens unit L5 and the sixth lens unit L6 move toward the image side when focusing from an infinite object to a close object.

Example 1

  • Focal length: 103.00-292.00
  • F-value: 2.90
  • Half angle of view: 11.86-4.24
  • Image height: 21.64
  • Total length: 333.61
  • Back focus: 31.93

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 9-18mm f/4 And RF 10-18mm f/4 Lenses

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Another Canon patent application that was published yesterday.

Canon patent application 2023099389 (Japan, published 7/13/2023) discusses optical formulas and methods for two ultra wide zoom lenses.

From the patent literature:

A compact and lightweight zoom lens that has a wide angle of view and high optical performance over the entire zoom range is provided.

Description of the Related Art

In recent years, zoom lenses used in imaging apparatuses are required to have a wide angle of view and high optical performance as imaging apparatuses have become more sophisticated. Further, as a zoom lens having a wide angle of view at the wide-angle end, a negative lead type zoom lens in which a lens group having a negative refractive power precedes the zoom lens is known.
However, in the zoom lens disclosed in Patent Document 1, the focal length of the first lens group is set to be small in order to widen the angle of view. . In addition, the back focus and the refractive power of the first lens group are not appropriate, and it is difficult to further reduce the diameter of the front lens and shorten the total length. The zoom lens disclosed in Patent Document 2 has a short back focus and a refractive power arrangement suitable for shortening the total length. However, the lens groups succeeding the first lens group all have positive refractive power, and it is difficult to narrow the position of the front principal point toward the first lens group when viewed as the entire succeeding group. is difficult.
In order to obtain a compact and lightweight zoom lens that has high optical performance over the entire zoom range while achieving a wide angle, the refractive power and lens configuration of the first lens group, and the lens groups following the first lens group It is important to set the refracting power and placement position of the lens appropriately.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compact and lightweight zoom lens that has a wide angle of view and high optical performance over the entire zoom range, and an imaging apparatus having the zoom lens.

Example 1

  • Focal length: 9.27-17.46
  • F-value: 4.12
  • Half angle of view: 63.98-51.10
  • Image height: 19.00-21.64
  • Overall length: 108.47-100.80
  • Back focus: 15.71-23.00

Example 2

  • Focal length: 10.01-17.46
  • F-value: 4.12
  • Half angle of view: 62.21-51.10
  • Image height: 19.00-21.64
  • Overall length: 106.74-99.55
  • Back focus: 12.36

More Canon patents are listed here.

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Canon Patent: RF 200mm f/2 IS Lens For EOS R System

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And here we have another Canon patent published today.

Canon patent application 2023099385 (Japan, published 7/13/2023) discusses optical formulas for a RF 200mm f/2 IS lens.

From the patent literature:

To provide an optical system having a plurality of focusing groups and anti-vibration groups that can be made compact and lightweight in addition to excellent optical performance.

Description of the Related Art

In a telephoto lens equipped with a plurality of focusing groups that move during focusing from infinity to the closest object and a vibration reduction group for correcting image blur, in addition to good optical performance, There is a demand for miniaturization and weight reduction of the entire lens system.
The present invention provides an optical system having a plurality of focusing groups and anti-vibration groups, which can be reduced in size and weight in addition to excellent optical performance.

Example 1

  • Focal length: 195.00
  • F-value: 2.05
  • Half angle of view: 6.33
  • Image height: 21.64
  • Overall length: 184.49
  • Back focus: 22.35

More Canon patents are listed here.

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Canon Patent: RF 20-60mm f/4.5-6.3 Lens For EOS R System

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And here we have another Canon patent application published today.

Canon patent application 2023099391 (Japan, published 7/13/2023) discusses optical formulas and methods for an RF 20-60mm f/4.5-6.3 lens for the EOS R system. Is this a possible new kit lens?

From the patent literature:

A zoom lens and an imaging device having the same

A compact, lightweight zoom lens with high optical performance and an imaging device and an imaging system having the zoom lens are provided.

Description of the Related Art

A zoom lens used in an imaging apparatus is required to have a wide angle of view, a small size, and a light weight. As a wide-angle zoom lens, a so-called negative lead type zoom lens is known, in which a lens group having a negative refractive power is arranged closest to the object side.
However, in the zoom lens disclosed in Patent Document 1, although the size and weight of the zoom lens have been reduced, various aberrations have not been satisfactorily corrected, resulting in insufficient optical performance. [0007]The present invention provides a zoom lens that is compact and lightweight and has high optical performance, and an imaging apparatus and an imaging system having the zoom lens.

Example 1

  • Focal Length: 24.71-48.53
  • F-value: 4.63-6.48
  • Half angle of view: 36.23-2308
  • Image height: 18.10-20.68
  • Overall length: 105.60-99.03
  • Back focus: 16.94-37.19

Example 2

  • Focal Length: 20.91-48.50
  • F-value: 4.63-6.49
  • Half angle of view: 41.17-23.03
  • Image height: 18.02-20.61
  • Total length: 120.00-100.66
  • Back focus: 10.49-31.34

Example 3

  • Focal Length: 20.61-58.50
  • F-value: 4.64-6.49
  • Half angle of view: 41.17-19.41
  • Image height: 18.02-20.61
  • Overall length: 135.00-125.50
  • Back focus: 10.49-11.70

More Canon patents are listed here.

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Canon Patent: RF 100mm f/1.4, RF 85mm f/1.4 And More Prime Lenses

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Here is a new Canon patent, the first of four that have been published today.

Canon patent application 2023099386 (Japan, published 7/13/2023) discusses optical formulas for a bunch of fast prime lenses.

From the patent literature:

To provide an optical system capable of satisfactorily correcting aberrations over a wide range of object distances while achieving miniaturization of a focus lens group.

Description of the Related Art

In recent years, an optical system used in an imaging apparatus has achieved a reduction in the size of the entire lens diameter of a focus lens group. It is required to be able to satisfactorily correct surface curvature and the like. As an optical system that satisfies these requirements, Patent Document 1 discloses a positive refractive power first lens group, a negative refractive power focus lens group, and a positive refractive power lens group, which are arranged in order from the object side to the image side. is disclosed having a focus lens group of .
However, in the optical system described in Patent Document 1, when the aperture of the optical system is increased, the focal length of the focus lens group having a positive refractive power and the second optical system arranged on the image side of the focus lens group The focal length of the 4 lens group is not properly set. For this reason, in the optical system described in Patent Document 1, it is difficult to suppress aberration fluctuations during focusing when the optical system has a large aperture.

SUMMARY OF THE INVENTION

The present invention provides an optical system capable of satisfactorily correcting aberrations over a wide range of object distances while achieving a compact focus lens group.

Example 1

  • Focal length: 82.50
  • F-value: 1.46
  • Half angle of view: 14.69
  • Image height: 21.64
  • Overall length: 112.50
  • Back focus: 13.00

Example 2

  • Focal length: 72.10
  • F-value: 1.46
  • Half angle of view: 16.70
  • Image height: 21.64
  • Overall length: 108.50
  • Back focus: 12.99

Example 3

  • Focal length: 97.50
  • F-value: 1.46
  • Half angle of view: 12.51
  • Image height: 21.64
  • Overall length: 125.50
  • Back focus: 13.00

Example 4

  • Focal length: 82.50
  • F-value: 1.24
  • Half angle of view: 14.69
  • Image height: 21.64
  • Overall length: 135.50
  • Back focus: 15.03

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: AF-Motor With Reduced Size And Lower Power Consumption

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A new Canon Patent application.

Canon patent application 2023096628 (Japan, published 7/7/2023) discusses technology and methods for a autofocus-driving motor with reduced size and lower power consumption.

The motor described in the the patent literature is a “linear motor”. Canon interchangeable lenses have a “ring-type USM”-motor for single-lens reflex cameras and a “NanoUSM”-motor for mirrorless cameras. Both are driven by ultrasonic waves, so this would be a new kind of motor driving Canon lenses.

From the patent literature:

A linear motor, a lens barrel, and a driving device that can improve power efficiency while suppressing an increase in external size are provided. BACKGROUND ART A linear motor is a motor that mainly generates force in one direction

It is used in a wide range of industrial fields. Linear motors are often used exclusively in linear drive applications and are often used in combination with linear guide mechanisms. Linear motors are classified into electromagnetic, pressure, friction, and tension/extrusion types according to the principle of thrust generation, and into finite tracks, endless tracks, etc. according to the drive range. be. In addition, devices that use mechanisms such as so-called rack and pinions and tires to convert the thrust of a normal rotary motor into linear thrust are also broadly classified as linear motors (linear actuators).

An example of the use of a linear motor is a focusing mechanism in a lens barrel. In the lens barrel, the focus operation is performed by moving the focus lens group inside the lens barrel back and forth on the optical axis perpendicular to the camera’s image sensor in order to focus on the subject at the desired position when shooting. is done. A linear motor is used to adjust the movement of the focus lens group.

Necessary conditions for the linear motor used in the focus mechanism in the lens barrel are that it has a size that fits inside the lens barrel, and that the maximum output and resolution of the thrust force sufficient to move and adjust the focus lens group are required. Being prepared, being quiet, etc. To meet these conditions, among the above categories, electromagnetic linear motors with finite trajectories are used, especially voice coil motors (VCMs), which generate the Lorentz force through a combination of permanent magnets and coils. may occur.

Since the VCM does not generate thrust when it is not energized, when using the VCM as a focus mechanism in the lens barrel, it is necessary to always energize the VCM to hold the focus lens group during use. For this reason, depending on the shooting scene, it may consume a large amount of power and the battery of the camera will be consumed faster than when using other friction type ultrasonic motors for the focusing mechanism in the lens barrel. be. Therefore, when a VCM is used as a focusing mechanism in the lens barrel, it is required to improve the power efficiency of the VCM.

In order to improve the power efficiency of a VCM with a finite orbit without increasing the external size, the efficiency of a magnetic circuit composed of a permanent magnet and a yoke (hereinafter simply referred to as magnetic efficiency), that is, the coil area of ​​the VCM The key is how to increase the density of the magnetic flux that contributes to the generation of thrust. The magnetic circuit here is an expression that compares the flow of magnetic flux in space to the flow of current in a circuit, and indicates the direction and magnitude of the magnetic flux density at each point. itself is also shown. In addition, in general finite orbit VCM, it is known that the magnetic efficiency is relatively lower at both ends of the drive stroke than at the center, and it is important in practice to suppress this. (See, for example, Patent Document 1).

However, in the VCM of Patent Document 1, since the magnetic efficiency in the central portion of the driving stroke is reduced in order to equalize the magnetic efficiency in the driving stroke, there is a problem that the power efficiency as a whole deteriorates. In addition, since the configuration of Patent Document 2 requires a separate fixing means for fixing the magnet, there is a problem that the external size of the linear motor tends to increase.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a linear motor, a lens barrel, and a driving device that can improve power efficiency while suppressing an increase in external size.

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

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