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

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.

• 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