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

Canon filed new pancake lens patens. The new patent details include 45mm f/2.8, 40mm f/2.8, 35mm f/2.8, 28mm f/2.8 pancake lenses.

Currently Canon has two pancake lenses in their line-up, they are the EF 40mm f/2.8 STM and the EF-M 22mm f/2 STM. Egami discovered the new patent filed by Canon and all are for f/2.8 pancake lenses with a focal length of 45mm, 40mm, 35mm, 28mm.

Below are the patent details of the 45mm f/2.8, 40mm f/2.8, 35mm f/2.8, 28mm f/2.8 pancake lenses.

Canon 45mm f/2.8, 40mm f/2.8, 35mm f/2.8, 28mm f/2.8 Pancake Lenses

canon-pancake-lens-patents

  • 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 Eg