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.

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