JP 1980-021005 A — Tadashi Kojima, Reiko Mao
| 9 ELEMENTS / 9 GROUPS |
| 35–70mm |
| f/3.5-f/22 |
| 63°-34° |
| MFD 0.35m |
NO_INTERNAL_RECONSTRUCTION — patent publishes infinity zoom spacings only; 0.35 m production MFD is retained without an invented close-focus optical state.
| Element | Type | Glass |
|---|---|---|
| L1 | Plano-Convex Positive | E-F2 catalog-equivalent coefficient proxy (patent 620363; production supplier unspecified) |
| L2 | Negative Meniscus | J-LASF016 catalog-equivalent coefficient proxy (patent 773496; production supplier unspecified) |
| L3 | Biconcave Negative | J-LASF016 catalog-equivalent coefficient proxy (patent 773496; production supplier unspecified) |
| L4 | Positive Meniscus | E-F2 catalog-equivalent coefficient proxy (patent 620363; production supplier unspecified) |
| L5 | Biconvex Positive | J-LAK14 catalog-equivalent coefficient proxy (patent 697555; production supplier unspecified) |
| L6 | Positive Meniscus | BAC4 catalog-equivalent coefficient proxy (patent 569562; production supplier unspecified) |
| L7 | Positive Meniscus | S-BSL7 catalog-equivalent coefficient proxy (patent 516641; production supplier unspecified) |
| L8 | Biconcave Negative | S-TIH6 catalog-equivalent coefficient proxy (patent 805254; production supplier unspecified) |
| L9 | Biconvex Positive | E-F2 catalog-equivalent coefficient proxy (patent 620363; production supplier unspecified) |