Tamron 90mm f/2.8 and Sigma 180mm f/2.8 Macro Lens Patents

Egami spotted two new patents filed in Japan. The new patents include Tamron 90mm f/2.8 and the Sigma 180mm f/2.8 macro lenses.

It is not clear if both macro lens patents for the former  Tamron SP 90mm F/2.8 Di MACRO 1:1 VC USD and Sigma APO MACRO 180mm F2.8 EX DG OS HSM lens. Both macro lenses employs a glass material.

Another filed patent shows that Tamron is also working on a 45mm f/2.8 Macro VC lens for Four Thirds cameras.

Sigma-180mm-f2.8-Macro-lens-patent

Tamron-90mm-f2.8-Macro-lens-patent

Tamron 90mm f/2.8 Macro Lens Details

Description and self-interpretation of the patent literature

  • Patent Publication No. 2013-122559
    • Publication date 2013.6.20
    • Filing date 2011.12.12
    • Related 2013-122558 The version without anti-vibration
  • Example 1
    • Magnification INF – X0.5 – X1.0
    • Focal length f = 92.74 – 81.62 – 64.66mm
    • Fno 2.89 -. 4.06 – 5.75
    • Angle of view 2ω = 13.12 – 7.72 – 4.03 °
    • Overall optical length 158.72mm
    • 14 pieces in 11 groups Lens Construction
    • Two XLD glass
  • Tamron patents
    • 6-group configuration of positive and negative positive negative positive
    • (To the image side, and the fourth group and the third group is the object side is the second group) inner focus
    • Shake correction (Group 5)

Sigma 180mm f/2.8 Macro Lens Details

Description and self-interpretation of the patent literature

  • Patent Publication No. 2013-104994
    • Publication date 2013.5.30
    • Filing date 2011.11.14
  • Example 1
    • Magnification INF – 1:2 – 1:1
    • Focal length f = 174.60 – 133.36 – 101.19mm
    • Fno 2.91 -. 4.72 – 5.32
    • Angle of view 2ω 14.07 – 5.23 – 1.98 °
    • 19 pieces of 14-group lens configuration
    • Three FLD glass
  • Sigma patents
    • 6-group configuration of positive and negative positive negative positive
    • (Second set to the image side, the third lens group moves toward the object side) inner focus
    • Shake correction (Group 5)
    • Prevent enlarged by placing a group of smaller axial light beam, the anti-vibration unit

via EG