Canon Patent: 10-20mm F2-2.8 And 10-30mm F2-2.8 Lenses

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A new Canon patent application was spotted. Two wide angle zoom lenses.

Canon patent application 2023120768 (Japan, published 8/30/2023) discusses optical formulas for two relatively fast wide angle zoom lenses:

  • 10-20mm f2-2.8
  • 10-30mm f2-2.8

From the patent literature:

A zoom lens that is advantageous in terms of wide angle of view, small size, high optical performance, and the like is provided.

Description of the Related Art

Zoom lenses used in imaging devices such as surveillance cameras, digital still cameras, video cameras, and broadcasting cameras are desired to have a wider angle of view and a smaller size. Patent Documents 1 and 2 disclose a negative lead type zoom lens as a compact zoom lens with a wide angle of view.

The above zoom lens is also required to have high optical performance corresponding to high image quality such as 8K image quality.

An object of the present invention is, for example, to provide a zoom lens that is advantageous in terms of wide angle of view, small size, and high optical performance.

Example 1

  • Focal length: 10.41-20.81
  • F-value: 2.05-2.84
  • Half angle of view: 59.1-29.7

Example 2

  • Focal length: 10.79-28.04
  • F-value: 2.00-3.17
  • Half angle of view: 58.9-22.3

More Canon patents are listed here.

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Canon Patent: RF 100-300mm F2.8 Telephoto Zoom Lens

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Here is a new Canon patent application, yet for another RF mount lens. A rather interesting one, although it refers to ab already released lens: the Canon RF 100-300mm f/2.8L IS USM.

Canon patent application 2023117937 (Japan, published 8/24/2023) discusses optical formulas for a fast telephoto zoom lens, a telephoto zoom that keeps f/2.8 over the zoom range.

Excerpt from the patent literature:

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 all object distances.

Description of the Related Art

In recent years, zoom lenses used in image pickup apparatuses are required to have high optical performance at all object distances from infinity to the shortest distance, and to be quiet during focusing. In order to meet these demands, a zoom lens has been proposed that performs focusing by moving two lens groups along different trajectories (see Patent Documents 1 and 2).

In a large-aperture telephoto zoom lens with a long focal length and a small F-number, if the focus group is arranged near the diaphragm or closer to the object side than the diaphragm, the lens diameter of the focus group increases, making it difficult to reduce the weight . As a result, the load on the actuator for driving the focus group increases, making it difficult to perform quiet and high-speed focusing. In order to reduce the weight of the focus group, it is important to appropriately set the arrangement of the focus group and the refractive power of the front and rear lens groups.

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 object distance.

Example 1

  • Focal length: 103.00-292.00
  • F-value: 2.89-2.91
  • Half angle of view: 11.86-4.24
  • Image height: 21.64
  • Overall length: 334.46
  • Back focus: 32.73

Example 2

  • Focal length: 120.00-294.00
  • F-value: 2.91
  • Half angle of view: 10.22-4.21
  • Image height: 21.64
  • Total length: 350.00
  • Back focus: 37.47

As I said at the beginning, the Canon patent application refers to an already released lens. More Canon patent applications are listed here.

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Canon Patent: Smaller Form Factor For Built-in Teleconverter

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Here is a new Canon patent application. I rather interesting one.

Canon patent application 2023118490 (Japan, published 8.25.2023) discusses methods and technology for a built-in teleconverter with a smaller form factor, i.e. the miniaturization of the teleconverter.

From the patent literature:

A large space is required for inserting or retracting a conversion lens inside an optical device, making it difficult to miniaturize the optical device.

Description of the Related Art

In optical equipment such as digital cameras, video cameras, and interchangeable lenses, it is known that the focal length range can be changed by inserting a conversion lens into the optical path.

Patent Document 1 discloses a technique for moving a conversion lens built into a camera body between an insertion position inserted into an optical path and a retracted position retracted out of the optical path. The built-in conversion lens described here is retracted in the space between the prism that guides the subject image to the finder and the strobe that is stored above the lens barrel.

However, the built-in conversion lens described in Patent Document 1 is moved to the retracted position using a dedicated actuator. Therefore, a space for arranging the actuator inside the lens is required, and it is difficult to suppress the enlargement of the lens.

Accordingly, the present invention provides an optical apparatus that has a built-in conversion lens so that a space for inserting or withdrawing the built-in conversion lens can be secured while suppressing an increase in the size of the lens. for the purpose.

More Canon patents are listed here.

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Canon Patent: 800mm f/5.6 IS, 1000mm f/8 IS And 1200mm f/8 IS Lenses

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A new Canon patent application. Canon patent application 2023107573 (Japan, published 8/3/2023) discusses optical formulas for three telephoto lenses:

  • 800mm f/5.6 IS
  • 1000mm f/8 IS
  • 1200mm f/8 IS

From the patent literature:

An object of the present invention is to provide an optical system in which various aberrations are satisfactorily corrected while being compact and lightweight, and an imaging apparatus having the optical system.

Description of the Related Art

A telescopic optical system used in an imaging apparatus is required to have a long focal length and a small F-number (large aperture). Patent Documents 1 and 2 disclose a first lens group with positive refractive power, a second lens group with positive or negative refractive power, and a third lens group with positive or negative refractive power, which are arranged in order from the object side to the image side. An optical system is disclosed, consisting of lens groups, with a second lens group moving during focusing.

Here, it is also desired that the telescopic optical system be compact and lightweight, and that various aberrations such as chromatic aberration and spherical aberration are well corrected. However, when trying to increase the aperture of a telescopic optical system, the effective diameter of the lens arranged on the object side becomes particularly large, making it difficult to reduce the size and weight of the entire system. Therefore, in order to realize the above-mentioned demands, it is important to appropriately set the optical arrangement of each lens group that constitutes the optical system, and the refractive power and arrangement of each lens that constitutes each lens group.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an optical system in which
various aberrations are satisfactorily corrected while being compact and lightweight, and an imaging apparatus having the optical system.

Example 1

  • Focal length: 820.00
  • F-value: 5.90
  • Half angle of view: 1.51
  • Image height: 21.64
  • Total length: 437.08
  • Back focus: 88.12

Example 2

  • Focal length: 1180.10
  • F-value: 8.00
  • Half angle of view: 1.05
  • Image height: 21.64
  • Total length: 550.00
  • Back focus: 140.36

Example 3

  • Focal length: 1000.0
  • F-value: 8.00
  • Half angle of view: 1.24
  • Image height: 21.64
  • Total length: 477.48
  • Back focus: 115.01

More Canon patents are listed here.

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Canon Patent: RF 24-300mm f/2.8-5.6 IS, RF 24-240mm f/2-5.6 IS And RF 40-350mm f/2.8-5.6 IS

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And another Canon patent for lenses for the RF mount.

Canon patent application 2023104137 (Japan, published 7/28/2023) discusses optical formulas for three zoom lenses for the RF mount:

  • RF 24-300mm f/2.8-5.6 IS
  • RF 24-240mm f/2-5.6 IS
  • RF 40-350mm f/2.8-5.6 IS

From the patent literature:

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

To provide a zoom lens that is compact as a whole, has a high zoom ratio, and has high optical performance over the entire zoom range.

BACKGROUND ART

In recent years, there has been a demand for a zoom lens used in an imaging apparatus having an imaging device to have a compact overall system, a high zoom ratio, and high resolution (high optical performance). . In particular, zoom lenses are required to have high optical performance with substantially uniform resolving power from the center of the screen to the periphery of the screen.

However, in the zoom lenses disclosed in Patent Documents 1 and 2, since the relationship between the refractive powers of the lens groups is not appropriate, the lens size increases when the zoom ratio is increased, and astigmatism at the wide-angle end and coma at the telephoto end gets worse.

The present invention provides a zoom lens that is compact overall, has a high zoom ratio, and has high optical performance over the entire zoom range.

More Canon patents are listed here.

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Canon Patent: RF 300mm f/2.8 IS And RF 400mm f/2.8 IS

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And yet another Canon patent application: two telephoto fast primes for the RF mount.

Canon patent application 2023104022 (Japan, published 7/28/2023) discusses optical formulas for two fast telephoto prime lenses for the RF mount: RF 300mm f/2.8 IS and RF 400mm f/2.8 IS.

From the patent literature:

Optical System and Imaging Device Having the Same

Description of the Related Art

An optical system used in an imaging apparatus is required to be compact and lightweight as a whole, and to have high optical performance capable of satisfactorily correcting various aberrations including chromatic aberration. As a compact optical system, a so-called telephoto type optical system is known in which a lens group with positive refractive power is arranged on the object side and a lens group with negative refractive power is arranged on the image side. However, in the telephoto type optical system, the longer the focal length, the larger the entire system, and the use of a lens with a large diameter or a heavy lens tends to increase the weight of the entire optical system.

Example 1

  • Focal length: 294.99
  • F-value: 2.90
  • Half angle of view: 4.19
  • Image height: 21.64
  • Overall length: 280.25
  • Back focus: 37.47

Example 2

  • Focal length: 390.00
  • F-value: 2.90
  • Half angle of view: 3.18
  • Image height: 21.64
  • Overall length: 370.50
  • Back focus: 37.00

More Canon patents are listed here.

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