JP1996-327896 A — Yoshinobu Asakura
| 8-ELEMENT / 6-GROUP PATENT MODEL |
| 390 mm PATENT HEADER / 391.43 mm COMPUTED EFL |
| F/4.59 DESIGN |
| 2ω = 6.4° |
| PUBLISHED 3 m INNER FOCUS |
PUBLISHED inner focus: Gr2 (L4-L7, surfaces 7-12) moves imageward from infinity to 3 m. T6 changes 29.311→43.262 mm and T12 changes 21.978→8.028 mm. Raw patent endpoints are preserved; their adjacent-gap sum differs by 0.001 mm at close focus because of source rounding.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | Unmatched (493836 Minolta AD/ED fluorophosphate; no compatible public coefficient row) |
| L2 | Biconvex Positive | Unmatched (493836 Minolta AD/ED fluorophosphate; no compatible public coefficient row) |
| L3 | Biconcave Negative | N-KZFS8 (SCHOTT catalog equivalent; patent 721334; production supplier unspecified) |
| L4 | Negative Meniscus (concave to image) | E-F2 (HOYA catalog equivalent; patent 620363; production supplier unspecified) |
| L5 | Positive Meniscus (concave to image) | S-FSL5 (OHARA catalog equivalent; patent 487702; production supplier unspecified) |
| L6 | Biconcave Negative | N-SSK5 (SCHOTT catalog equivalent; patent 658509; production supplier unspecified) |
| L7 | Positive Meniscus (concave to image) | J-SF03 / H-ZF52 / FDS90 catalog-equivalent dense-flint class (patent 846238; production supplier unspecified) |
| L8 | Positive Meniscus (convex to image) | S-FSL5 (OHARA catalog equivalent; patent 487702; production supplier unspecified) |