Canon patent for EF 600mm f/4 DO IS USM lens


Canon filed a patent for an EF 600mm f/4 DO IS lens, i.e. a lens with diffractive optical elements.

  • Patent Publication No. 2015-11171
    • Published 2015.1.19
    • Filing date 2013.6.28
  • Example 2
    • Focal length 588.30mm
    • Fno. 4.12
    • Angle of view 2.11 °
    • Image height 21.64mm
    • The total lens length 397.80mm
    • BF 2.02mm
    • Positive ShiboTadashi
    • Inner focus
    • Vibration control
[via Egami]

Canon patent for lubricating body cap


The Canon patent describes a body cap that keeps the lens mount of a DSLR lubricated. To be honest I can’t grab the utility of this, except that it could concern the electric contacts (keeping them clean) . Since we get this patent literature translated by a machine, I am never sure the translated words are any helpful.

  • Patent Publication No. 2015-121747
    • Published 2015.7.2
    • Filing date 2013.12.25
  • Canon patents
    • Mount Cap
    • The mount and abutting surface, and oil-impregnated possible member, such as a porous plastic
[via Egami]

Canon Hexa Pixel Auto-Focus patent (for light-field photography?)


A pretty interesting patent. It appears Canon is working on the next generation of the technology introduced with the EOS 70D, i.e. Dual Pixel Auto-Focus. With a difference: this is Hexa Pixel Auto-Focus, and AF is obtained by plane phase difference of 16 sub-pixels. Not bad, eh? Might be the next game changing technology by Canon.

Moreover, and if I got the machine translated patent description right, this patent may be related to another Canon patent for a video camera featuring light-field technology. The patent also mentions AF microadjustment, but I am not sure I got it right: according to the patent literature, it seems to be a technology for automatic auto-focus microadjustment. As usual, given the hard to understand patent literature, any interpretative help is welcome.

  • Patent Publication No. 2015-121778
    • Published 2015.7.2
    • Filing date 2013.11.21
  • Canon patents
    • Image plane phase difference AF using 16 sub-pixels
    • Light field contrast AF that uses a
    • It does focus adjustment (Microadjustment) from the difference between the image plane phase difference AF and contrast AF
[via Egami]

Canon patent for videocamera with compound eye-like lens and light-field technology


Canon filed a patent for what appears to be a Lytro-like technology. The patent refers to a “compound eye” lens, i.e. an optic element with several lenses, each having a different focal distance. Such a device is capable of refocusing images after being taken.

This is called Light-field photography, and Wikipedia has a definition for it:

A light field camera (also known as plenoptic camera) captures information about the intensity of light in a scene, and also captures information about the direction that the light rays are traveling in space. One type of light field camera uses an array of micro-lenses placed in front of an otherwise conventional image sensor; to sense intensity, color, and directional information.

Light-field photography is part of computational photography, and again we have a good definition:

Computational photography or computational imaging refers to digital image capture and processing techniques that use digital computation instead of optical processes. Computational photography can improve the capabilities of a camera, or introduce features that were not possible at all with film based photography, or reduce the cost or reduce the size of camera elements. […] Light field cameras use novel optical elements to capture three dimensional scene information which can then be used to produce 3D images, enhanced of depth-of-field, and selective de-focusing (or “post focus”). Enhanced depth-of-field reduces the need for mechanical focusing systems

However, the patent refers to a video camera. This makes everything more interesting. I couldn’t find any reference to a sensor technology in the patent description. I wonder if this is going to feature a new sensor technology. I am not an expert in this domain, so any help is welcome.

  • Patent Publication No. 2015-122677
    • Published 2015.7.2
    • Filing date 2013.12.25
  • Canon patents
    • a plurality of lenses that focus processing is different
    • Sequentially performs the subject detection to the focal length is long order

The patent was spotted by Egami (translation).

"Lytro ILLUM 2014 front" by Cathy Bremer, - Cathy Bremer, Licensed under CC BY-SA 4.0 via Wikimedia Commons -

The Lytro ILLUM light field camera from 2014 (Photo: “Lytro ILLUM 2014 front” by Cathy Bremer, – Cathy Bremer, Licensed under CC BY-SA 4.0 via Wikimedia Commons)

Canon patent for EF 15-105mm f/2.8-5.6 lens


Canon filed a patent for an EF 15-105mm f/2.8-5.6 lens.

  • Patent Publication No. 2015-118141
    • Published 2015.6.25
    • Filing date 2013.12.17
  • Example
    Example Zoom ratio Focal length Fno. Half angle Image height Overall length of the lens BF
    1 4.12 24.75 52.09 101.92 3.60 4.81 5.83 41.16 22.56 11.98 21.64 146.25 166.83 195.25 38.99 58.34 73.70
    2 6.81 15.40 22.95 104.92 2.88 3.39 5.60 41.57 30.76 7.42 13.66 149.46 154.42 222.88 38.13 46.49 77.97
  • Canon patents
    • Positive and negative positive and negative positive and negative positive 7-group zoom
    • Inner focus (fourth group)
[via Egami]

Canon Patent for EF/EF-S adapter for full-frame mirrorless camera


This is a very interesting patent, a patent that hopefully points to something that will hit the market.

The patent refers to an adapter for a full-frame mirrorless camera. The adapter has a switch to change between EF and EF-S lenses.

  • Patent Publication No. 2015-118208
    • Published 2015.6.25
    • Filing date 2013.12.18
  • Canon patents
    • Flange back is shorter body
    • Flange back is long, a lens having the same image circle as the image pickup device body
    • Flange back is long, a lens with a smaller image circle than the image pickup device body
    • Mount adapter to change the diameter of the flare cut stop, depending on the image circle of mounting the lens

May a full-frame mirrorless camera by Canon finally be on its way?

[via Egami]