JP S56-150717 A — Hisashi Tokumaru, Mitsuo Yasukuni
| 12 ELEMENTS / 8 GROUPS |
| f = 77–146 mm (design) |
| F/4.1 (design) |
| Y′ = 21.6 mm |
NO_INTERNAL_RECONSTRUCTION: the patent identifies F as the focusing group but publishes only infinity-focus zoom spacings. The production 1.2 m MFD is retained as product metadata; no finite-focus internal movement is invented.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | 517641 crown / BK7-family class |
| L2 | Biconvex Positive | 517641 crown / BK7-family class |
| L3 | Biconcave Negative | 805255 dense flint / SF6-family class |
| L4 | Biconvex Positive | 805255 dense flint / SF6-family class |
| L5 | Biconcave Negative | Unmatched (621613 dense crown; no public catalog glass at this coordinate, nearest SK16 class at Δnd −0.0009, Δνd −1.0) |
| L6 | Biconcave Negative | Unmatched (750501 lanthanum crown/flint boundary; no public catalog glass at this coordinate) |
| L7 | Biconvex Positive | 589611 crown class (L-BAL35 / N-SK5 / K-SKLD5 coordinate family) |
| L8 | Negative Meniscus | 740283 dense flint / S-TIH3 / H-ZF5 class |
| L9 | Biconvex Positive | 658509 dense crown / N-SSK5 class |
| L10 | Biconcave Negative | Unmatched (807316 lanthanum dense flint; coordinate of discontinued Schott LaSF8, no public dispersion coefficients) |
| L11 | Biconvex Positive | 673322 dense flint / SF5 class |
| L12 | Negative Meniscus | 671518 crown class (H-LaK67 coordinate equivalent, Δnd −0.0010) |