Canon 45mm f/2.8, 40mm f/2.8, 35mm f/2.8, 28mm f/2.8 Pancake Lens Patents

40mm f2.8 pancake lens
EF 40mm f/2.8 STM Pancake Lens

Here are some new pancake lens patents from Canon. A total of 4 pancake lenses to be announced. They are Canon EF 45mm f/2.8Canon EF 40mm f/2.8Canon EF 35mm f/2.8Canon EF 28mm f/2.8.

canon pancake lens patents

 

Detail: (Translated by Google)

  • Patent Publication No. 2013-137411
    • Publication date 2013.7.11
    • Filing date 2011.12.28
  • Example
    embodiment
    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

via: egami