Canon Patent For 55-250mm f/4-5.6 IS STM Lens For EOS M System

Egami (translated) spotted a patent for a 55-250mm f/4-5.6 IS STM lens with EF-M mount. Curious because there is already an EF-M 55-200mm f/4.5-6.3 IS STM lens for the EOS M system.

• Patent Publication No. 2014-199421
  • Published 2014.10.23
  • Filing date 2013.3.13
• Example
  • Zoom ratio 4.36
  • Focal length 56.14-134.30-245.00mm
  • Fno. 4.50-5.09-6.45
  • Half angle ω = 13.67-5.81-3.19 °
  • Image height Y = 13.66mm
  • Overall length of the lens 119.39-157.52-184.41mm
  • BF 22.04-27.75-50.36mm
  • Positive and negative positive and negative negative 5-group zoom
  • Inner focus (group 4)