NIKON AF ZOOM-NIKKOR 28-200mm f/3.5-5.6 G IF-ED

US 6,621,643 B2 — Haruo Sato

12 physical elements / 11 groups (14 material layers modeled)
Production: 28-200mm f/3.5-5.6
Patent design: 29.1-192mm f/3.6-5.9
3 ED elements
3 aspherical components / 4 aspherical surfaces
Published G2 inner focus; modeled close distance 0.430 m

Focus Mechanism

PUBLISHED G2 inner focusing. The second group translates toward the object while D5 decreases and D14 increases with D5 + D14 conserved at each zoom station. Published close-state G2 travel is 1.36966 mm at 29.1 mm, 1.80154 mm at 50 mm, and 8.25666 mm at 192 mm. The patent model focuses to 0.430 m from the image plane at all three zoom stations; the production lens was marketed at 0.44 m.

Optical Elements (12 physical; 14 modeled media)

ElementTypeGlass
L11aNegative Meniscus847238 — dense flint class
L11bPositive MeniscusJ-LAK01 (Hikari; patent code 640601)
L12Positive MeniscusJ-FKH1 (Hikari; patent code 498825)
L21rNegative Meniscus (1× Asph, Hybrid Resin)Unmatched (optical resin, nd=1.553890, νd=38.09)
L21gNegative Meniscus835427 — lanthanum flint class
L22Biconcave Negative773496 — lanthanum flint class
L23Biconvex Positive808228 — very dense flint class
L24Biconcave Negative773496 — lanthanum flint class
L31Biconvex PositiveJ-FKH1 (Hikari; patent code 498825)
L32Positive MeniscusJ-FKH1 (Hikari; patent code 498825)
L33Negative Meniscus847238 — dense flint class
L1Biconvex Positive (2× Asph)517641 — borosilicate crown class
L2rPositive Meniscus (1× Asph, Hybrid Resin)Unmatched (optical resin, nd=1.553890, νd=38.09)
L2gNegative Meniscus804466 — lanthanum flint class