Canon Patent: More Pancake By Canon (45mm, 40mm, 35mm, 28mm, all f/2.8)

Canon Patent
45mm f/2.8
Canon Patent
35mm f/2.8
Canon Patent
40mm f/2.8
Canon Patent
28mm f/2.8

Japanese site Egami (translated) spotted new patents filed by Canon. All are for f/2.8 pancake lenses: 45mm, 40mm, 35mm, 28mm. Canon has two pancake lenses in their line-up: the EF 40mm f/2.8 STM and the EF-M 22mm f/2 STM

  • Patent Publication No. 2013-137411
    • Publication date 2013.7.11
    • Filing date 2011.12.28
  • Example
    Focal length Fno. Half angle Configuration length Total length BF
    One 45.00 2.80 25.68 20.00 57.99 37.99
    Two 39.00 2.80 29.02 23.50 62.50 39.00
    Three 35.00 2.80 31.72 25.00 63.01 38.01
    Four 28.00 2.80 37.69 27.00 65.00 38.00

    Image height = 21.64mm

  • Canon patent
    • The longer the focus back a Gaussian type, field curvature occurs
    • 2-group configuration positive positive, Gauss type


Canon Patent
Canon Patent

Canon Patent: 85mm f/1.2, 85mm f/1.8, 135mm f/2, 50mm f/1.4

Canon Patent
50mm f/1.4
Canon Patent
135mm f/2
Canon Patent
85mm f/1.8
Canon Patent
85mm f/1.2

Egami (translated) spotted new patents for lenses filed by Canon: 85mm f/1.2, 85mm f/1.8, 135mm f/2 and 50mm f/1.4.

  • Patent Publication No. 2013-114133
    • Publication date 2013.6.10
    • Filing date 2011.11.30
  • Example
    Focal length Fno. The overall length of the lens BF Lens constitution
    One 85.00 1.24 122.56 38.35 10 pieces of six groups
    Two 83.30 1.80 116.11 39.11 10 sheets in 7 groups
    Three 132.30 2.06 162.67 43.23 10 sheets in 7 groups
    Four 51.70 1.41 87.84 38.94 7 group nine

    Image height Y = 21.64mm

  • Factors that chromatic aberration of magnification chromatic aberration or axial chromatic aberration occurs
    • Reducing the total length
    • Focal length for a long time
  • Glass material Abbe number 70-90, of 1.4-1.5 refractive index
    • Possible correction of axial chromatic aberration
    • Must increase a curvature, spherical aberration and curvature of field is generated
  • Canon patent
    • I use a glass material having an anomalous partial dispersion of the predetermined
    • Consisting of organic and inorganic compound
[via Egami]

Canon Patent: 70-200mm f/4 Lens (Canon EF 70-200mm f/4L II On The Way?)

Canon Patent

Egami (translated) spotted a patent filed by Canon that most probably refers to the next iteration of the Canon EF 70-200mm f/4L USM, released in 2006. Canon has another 70-200 in their lineup, the image stabilized EF 70-200mm f/4L IS.

canon patent
  • Patent Publication No. 2013-105131
    • Publication date 2013.5.30
    • Filing date 2011.11.16
  • Example 1
    • Zoom ratio 2.68
    • Focal length f = 72.11-131.37-193.4mm
    • Fno. 4
    • Half angle ω = 16.7-9.35-6.38 °
    • Image height 21.64mm
    • The overall length of the lens 234.52mm
    • BF 50.12mm
  • Example 2
    • Zoom ratio 2.68
    • Focal length f = 72.14-130.58-193.38mm
    • Fno. 4
    • Half angle ω = 16.69-9.41-6.38 °
    • Image height 21.64mm
    • The overall length of the lens 213.85mm
    • BF 39.96mm
  • Example 3
    • Zoom ratio 2.68
    • Focal length f = 72.11-132.09-193.4mm
    • Fno. 4
    • Half angle ω = 16.7-9.3-6.38 °
    • Image height 21.64mm
    • The overall length of the lens 233.51mm
    • BF 49.05mm
  • Existing techniques
    • If you have a single focus group is easy aberration There is a change in the RF and IF
  • Canon patent
    • Inner zoom
    • Inner focus
    • Floating
    • MOD 300mm
    • β (Tele) = -0.5

Canon Patent For Liquid Optical Elements (liquid lens)

liquid lens
Liquid optical element
liquid lens liquid lens

Figure above: When electricity is applied the optical element gets a shape.

Another Canon patent spotted by Egami (translated).

Liquid lenses have a series of advantages over traditional lenses. Beside not having moving parts (and thus less mechanical parts), they respond quicker to electrical signals, they do not have a motor (you thought that USM was the big thing? Think again) and they are naturally much more silent. The lack of a motor also means such a lens needs less electrical power, hence the battery lasts longer. Liquid lenses are most likely going to be employed in compact cameras and/or smartphones. If you want a more scientific description about what liquid lenses are and do, I recommend this article.

It is not the first time Canon files a patent for a liquid lens (and yes, I shamelessly recycled some of the text of my previous post :-) ).

Patent description (machine translated):

  • Patent Publication No. 2013-101227
    • Publication date 2013.5.23
    • Filing date 2011.11.9
  • Canon patent
    • I drive a plurality of pumps
    • Drive pump liquid optical element to hold the end of the interface
    • When applied to the electrodes, electrowetting phenomenon in which the liquid moves to the interface from the drive pump occurs
    • Optical properties are changed by the movement of the liquid
    • By discretely and independently controlled and a voltage, enabling high-speed drive
[via Egami]