Skip to content

Canon Patent: 12-30mm f4-6.3 IS APS-C And 20-40mm f/4 IS With Inner Zoom

Canon Patent

A new Canon patent for two lenses for mirrorless cameras, one for APS-C and the other for full-frame. Both have inner zoom mechanism.

Canon patent application 2024076793 (Japan, published 6/6/2024) discusses optical formulas for two lenses with inner zoom:

  • 12-30mm f4-6.3 IS (APS-C)
  • 20-40mm f/4 IS (full-frame)

From the patent literature:

  • An object of the present invention is to provide a negative lead type wide-angle zoom lens that is small and lightweight and has high optical performance over the entire zoom range.
  • BACKGROUND ART In recent years, it has been desired that an imaging optical system used in an imaging device be a small zoom lens that has a wide angle of view and has high optical performance over the entire zoom range.
  • Patent Document 1 discloses a negative lead type wide-angle zoom lens in which a first lens group with a negative refractive power is disposed closest to the object side as a zoom lens whose entire system is small and whose angle of view can be easily widened. Proposed.
  • The negative lead type wide-angle zoom lens proposed in Patent Document 1 widens the angle of view by moving the first lens group with negative refractive power when zooming from the wide-angle end to the telephoto end. It achieves high optical performance.
  • However, the configuration in which the first lens group, which is large and has a large mass, is moved, as in the wide-angle zoom lens described in Patent Document 1, complicates the movement mechanism and is disadvantageous from the viewpoint of miniaturization and weight reduction.
  • The present invention provides a negative lead type wide-angle zoom lens that is compact and lightweight, yet has high optical performance over the entire zoom range.

Example 1

  • Focal length: 12.42-29.07
  • F value: 4.10-6.40
  • Half angle of view: 47.72-25.17
  • Image height: 11.37-13.66
  • Total length: 82.97
  • Back focus: 12.29

Example 2

  • Focal length: 14.40-29.10
  • F value: 4.10-6.29
  • Half angle of view: 43.40-25.14
  • Image height: 11.46-13.17
  • Total length: 75.06
  • Back focus: 11.78

Example 3

  • Focal length: 20.60-39.00
  • F value: 4.10
  • Half angle of view: 46.40-29.01
  • Image height: 17.94-20.74
  • Total length: 97.01
  • Back focus: 12.68

Example 4

  • Focal length: 20.60-48.50
  • F value: 4.10-5.88
  • Half angle of view: 46.40-24.04
  • Image height: 18.22-21.64
  • Total length: 106.52
  • Back focus: 19.41

More Canon patents are listed here.

[via asobinet]

Back To Top

Notice

This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy. If you want to know more or withdraw your consent to all or some of the cookies, please refer to the cookie policy.
By closing this banner you agree to the use of cookies.