Canon Patent: Converter Lens For EF-S 24mm F2.8 STM (increases focal length)

Canon Patent

I am not 100% sure I got this Canon patent application right. It seems to be about a magnifying optical system that increases the focal length.

The converter discussed in the patent literature appears to refer to the EF-S 24mm F2.8 STM lens (the master lens). From the patent literature:

BACKGROUND ART

A rear converter lens (hereinafter referred to as a converter lens) capable of enlarging the focal length of the entire system (increasing the focal length) by being placed between an interchangeable lens and an imaging device. It has been known.

In general, a converter lens has a negative refractive power, and the negative refractive power tends to increase as the magnification of the focal length increases. It is also known that if the curvature of the negative lens in the converter lens is increased in order to increase the negative refractive power, various aberrations such as coma due to the off-axis light flux are likely to occur.

In view of such problems, an object of the present invention is to provide a converter lens capable of obtaining high optical characteristics in the entire system when arranged on the image side of the master lens.

Master lens

  • Focal length: 24.50
  • F-value: 2.88
  • Half angle of view: 29.14
  • Image height: 13.66
  • Overall length: 64.83
  • Back focus: 35.68

Example 1

  • Focal Length: 39.54
  • F-value: 4.65
  • Half angle of view: 28.68
  • Image height: 21.64
  • Overall length: 89.59
  • Back focus: 13.96

Example 2

  • Focal length: 49.27
  • F-value: 5.79
  • Half angle of view: 23.71
  • Image height: 21.64
  • Overall length: 97.18
  • Back focus: 11.00

More Canon patent applications are listed here.

Canon Patent: Extension Grip With Easy To Change Batteries

Canon Patent

A potentially rather useful Canon patent was spotted: an extension grip that allows for uncomplicated change of the batteries.

Canon patent 2022125113 (Japan) discusses methods and technology for an extension grip where batteries can be changed easily. According to the patent drawings, it seems for a compact mirrorless camera, more or less in EOS RP style.

From the patent literature:

A camera accessory is provided in which a battery can be easily inserted into and removed from the camera while being attached to the bottom surface of the camera.

Description of the Related Art

Along with the miniaturization of cameras, an auxiliary grip attached to a camera has been provided as an imaging accessory for improving the holdability of the camera for users with large hands. Patent Document 1 discloses an auxiliary grip detachably attached to a grip portion of a camera. In addition, an auxiliary grip ( hereinafter referred to as an extended grip) is also provided.

However, if the extended grip is attached to the camera when attempting to insert or remove the battery from the bottom side of the camera, first the extended grip is removed from the camera, and then the cover member on the bottom of the camera is removed. It has to be opened, which is annoying for the user.

The present invention provides a camera accessory that allows the battery to be easily inserted and removed from the camera while attached to the bottom surface of the camera.

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

[via asobinet]

Canon Patent: Foldable Screen For A Compact Mirrorless Camera

Canon Patent

Well, that’s an interesting Canon patent: a foldable screen on the back of your future mirrorless camera.

Canon patent application 20220269152 and 20220272266 (both USA) discuss technology and methods to bring a foldable screen on the back of a mirrorless camera. The abstracts:

Pretty cool, I think. we have foldable screens on smartphones, and we will have them on other devices too, cameras included. The camera in the patent drawings looks like a very compact mirrorless camera.

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

[via Northlight Images]

Canon Patent: 20mm f/1.8, 28mm f/1.8 And 24mm f/1.8 With Backlight Control

Canon Patent

A new Canon patent for RF mount lenses: 20mm f/1.8, 28mm f/1.8 and 24mm f/1.8.

Canon patent application 2022122047 (Japan) discusses optical formulas for three RF mount lenses with backlight control. From the patent literature:

An object of the present invention is to provide an optical system that is less affected by unnecessary light and has high optical performance.

Description of the Related Art

There is a demand for further improvement in performance and miniaturization of photographing optical systems. [0005]When trying to improve the performance of an optical system, the number of lenses constituting the optical system increases. On the other hand, if an attempt is made to reduce the size of the optical system by shortening its overall length, the distance between the lenses constituting the optical system and the distance between the optical system and the imaging surface will be shortened. As a result, unnecessary light (ghost) caused by reflection of light on each lens surface easily reaches the imaging surface.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an optical system that is less affected by unnecessary light and has high optical performance.

Example 1

  • Focal length: 28.60
  • F-value: 1.85
  • Half angle of view: 37,1
  • Image height: 20.15
  • Total length: 81.00
  • Back focus: 13.20

Example 2

  • Focal length: 20.60
  • F-value: 1.85
  • Half angle of view: 46.4
  • Image height: 18.71
  • Overall length: 84.87
  • Back focus: 11.00

Example 3

  • Focal length: 24,72
  • F-value: 1.85
  • Half angle of view: 41.2
  • Image height: 19.34
  • Total length: 81.00
  • Back focus: 11.00

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

[via asobinet]

Canon Patent: Internal Liquid Cooling Device For Mirrorless Cameras

Canon Patent

Remember the Canon EOS R5 overheating soap opera? Maybe this Canon patent application comes from this hysteria.

Canon patent application 20220264767 (USA) discusses technology and methods for an active cooling system with magnetic fluid. The patent abstract:

This is pretty cool, me thinks: magnetic cooling fluid pumped by use of a magnetic field. The magnetic fluid is pumped through the camera body using magnets. Will we see it soon on a new Canon mirrorless camera?

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

[via NL]

Canon Patent: 30-90mm f/1.5, 18-45mm f/1.5, 70-210mm f/2.5 Cinema Lenses

Canon Patent

A new Canon patent and for once it doesn’t refer to RF mount lenses but for Cinema optics: 30-90mm f/1.5, 18-45mm f/1.5, 70-210mm f/2.5.

Canon patent application 2022119007 (Japan) discusses optical formulas for three lenses we think are Cinema or broadcasting lenses:

  • 30-90mm f/1.5
  • 18-45mm f/1.5
  • 70-210mm f/2.5

From the patent literature:

To provide a zoom lens that is advantageous in terms of, for example, a large aperture, small size and light weight, and high optical performance over the entire zoom range.

The lens diameter of the lens group closest to the object side in the first lens group is determined by the off-axis ray at the wide-angle end, and the lens diameter of the lens group closest to the image side in the first lens group is determined by the on-axis ray at the telephoto end. Therefore, if the first lens group is thickened, the size of the lens will increase if the aperture is to be further increased. In the zoom lens of Patent Literature 1, since the first lens group is thick, the zoom lens may become large if it is intended to accommodate a large-format sensor such as a Super 35 format or a full-frame format while maintaining the F-number.

Example 1

  • Focal length: 31.20-89.85
  • F-value: 1.51
  • Half angle of view: 25.38-9.35
  • Total length: 284.23
  • Back focus: 39.00

Example 2

  • Focal length: 21.00-80.57
  • F-value: 1.51
  • Half angle of view: 35.17-10.41
  • Total length: 288.03
  • Back focus: 39.00

Example 3

  • Focal length: 18.01-45.01
  • F-value: 1.51
  • Half angle of view: 39.422-18.20
  • Total length: 308.88
  • Back focus: 39.00

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

[via asobinet]