Canon Patent: 24-70mm f/4, 28-200mm f/2.8-5.6, 20-60mm f/2.8-4 And 50mm f/1.4 (composite opticals)

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A new Canon patent application for RF-mount lenses with composite optical elements.

Canon patent 2024039231 (Japan, published 3/22/2024) discusses optical formulas and methods for four lenses with composite optical elements:

  • 24-70mm f/4
  • 28-200mm f/2.8-5.6
  • 20-60mm f/2.8-4
  • 50mm f/1.4

Guess the most interesting of the bunch is the 50mm f/1.4 lens. From the patent literature:

  • An object of the present invention is to provide a composite optical element that is small and lightweight and has high optical performance.
  • BACKGROUND ART: In recent years, there has been an increasing demand for shorter overall length and lighter weight of photographic optical systems. In order to reduce the overall length and weight of the photographic optical system, there is a method of increasing the refractive power of each lens and introducing an aspherical lens to correct various aberrations that occur as a result.
  • As an aspherical lens for a photographic optical system, there is a composite element formed by molding a resin layer onto a glass lens.
  • Composite elements have a high degree of freedom in selecting the glass material for the glass lens, and are easy to mold, so they are characterized by being easy to introduce into photographic optical systems.
  • Patent Document 1 discloses an optical system in which chromatic aberration is corrected by using a material with a low partial dispersion ratio for the glass of a composite lens and combining it with a resin having a high partial dispersion ratio. If resin is used as an aspherical lens, chromatic spherical aberration and chromatic curvature of field will increase, which is undesirable.
  • Accordingly, an object of the present invention is to provide a composite optical element that is small and lightweight and has high optical performance.

Example 1

  • Focal length: 24-67.90
  • F value: 4.12
  • Half angle of view: 41.33-17.67
  • Image height: 19.39-21.64
  • Total length: 108.50-142.13
  • Back focus: 20.95-50.49

Example 2

  • Focal length: 15.30-45.00
  • F value: 4.12
  • Half angle of view: 41.68-16.51
  • Image height: 11.60-13.65
  • Total length: 83.50
  • Back focus: 17.67

Example 3

  • Focal length: 50.03
  • F value: 1.44
  • Half angle of view: 23.39
  • Image height: 21.64
  • Total length: 113.51
  • Back focus: 13.51

Example 4

  • Focal length: 28.40-197.00
  • F value: 2.90-5.70
  • Half angle of view: 37.30-6.27
  • Image height: 18.97-21.64
  • Total length: 151.14-220.00
  • Back focus: 13.50-47.04

Example 5

  • Focal length: 21.00-60.00
  • F value: 2.90-4.10
  • Half angle of view: 45.79-19.29
  • Image height: 18.37-21.62
  • Total length: 135.70-126.50
  • Back focus: 22.43

Example 6

  • Focal length: 390.03-275.02
  • F value: 2.91-3.08
  • Half angle of view: 3.21-4.52
  • Image height: 21.84-21.72
  • Total length: 347.00
  • Back focus: 46.20

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: 18-55mm F4-6.5 & 20-60mm F4-6.5 For Full Frame Mirrorless

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Two Canon patents today, this one and the one featured here.

Canon patent application 2023010106 (Japan, published 1/20/2023) discusses optical formulas for what seem to be two possible kit lenses, both for full frame mirrorless cameras, i.e. the RF mount:

  • 18-55mm f4-6.5
  • 20-50mm f4-5.6

From the patent literature:

A compact zoom lens that achieves high optical performance while widening the angle of view is provided.

In recent years, there has been a strong demand for a lens system used in an imaging apparatus to have high optical performance while the entire lens system is compact. In order to achieve good optical performance while miniaturizing the entire lens system, it is important to appropriately set the refractive power of each lens group, the moving conditions for zooming, and the like of each lens group. In particular, in a camera with a large image pickup element, when a desired magnification is secured while widening the angle, the front lens tends to become large, and it is necessary to appropriately configure each lens group.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compact zoom lens that achieves high optical performance while widening the angle of view.

Example 1

  • Focal length: 18.50-53.01
  • F-value: 4.11-6.48
  • Half angle of view: 49.17-22.02
  • Image height: 18.50-21.64
  • Overall length: 117.88-150.43
  • Back focus: 19.52-24.90

Example 2

  • Focal length: 19.72-53.16
  • F-value: 4.12-6.07
  • Half angle of view: 48.13-22.43
  • Image height: 18.50-21.64
  • Total length: 126.89-162.14
  • Back focus: 21.40-51.52

Example 3

  • Focal Length: 18.50-58.92
  • F-value: 4.12-6.48
  • Half angle of view: 49.09-19.95
  • Image height: 18.50-21.64
  • Total length: 132.01-160.73
  • Back focus: 24.47-37.26

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

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