NIKON AI ZOOM-NIKKOR 80-200mm f/4

US 4,452,513 — Yoshinari Hamanishi

13 ELEMENTS / 9 GROUPS
80-200mm f/4 (MARKETED)
80.0-195.2mm f/4 (DESIGN)
1.2m CLOSE FOCUS
ALL-SPHERICAL

Focus Mechanism

CONSTRAINED_RECONSTRUCTION: Nikon specifies a 1.2 m focal-plane minimum distance and parfocal one-ring operation. G1-only travel is code-solved as 17.047774 mm at 80 mm and 17.048840 mm at 195.2 mm, with G2-G4 and the image plane fixed. Patent 0.998 m and 0.680 m test states are not exposed.

Optical Elements (13 physical)

ElementTypeGlass
L11aNegative Meniscus805254 — dense flint class (catalog unresolved)
L11bBiconvex Positive620603 — crown class (catalog unresolved)
L12Positive Meniscus517641 — crown class (catalog unresolved)
L2aBiconcave Negative788475 — dense lanthanum glass class (catalog unresolved)
L2bBiconvex Positive755276 — dense flint class (catalog unresolved)
L2cBiconcave Negative581408 — light flint class (catalog unresolved)
L22Biconcave Negative589612 — crown class (catalog unresolved)
L3aBiconvex Positive620603 — crown class (catalog unresolved)
L3bNegative Meniscus755276 — dense flint class (catalog unresolved)
L41Positive MeniscusS-LAL52 (OHARA catalog equivalent for patent 670576; production supplier unspecified)
L42Biconcave NegativeJ-LAFH3 (HIKARI; 795287 match to patent 795286 class)
L43Negative Meniscus797455 — dense lanthanum glass class (catalog unresolved)
L44Biconvex Positive583465 — barium flint class (catalog unresolved)