JP 2021-076829 A — Takahiro Kitaguchi
| 12 LENS ELEMENTS / 9 GROUPS |
| 16.5534-33.8782 mm DESIGN |
| F/4.10925-F/4.12028 MODELED |
| 2ω = 107.1354°-66.3796° |
| 5 ASPHERICAL SURFACES / 3 ASPHERICAL LENSES |
CONSTRAINED_RECONSTRUCTION: G3 alone moves imageward. The three published infinity zoom anchors are retained and 30 derived control points are inserted along their piecewise-linear zoom path. At all 33 points, D17 increases and D20 decreases equally, preserving D17 + D20 and fixed BF while solving the 0.25 m sensor-plane conjugate. Between-knot states remain ordinary piecewise-linear UI interpolation. The patent publishes the mechanism and direction but no close-focus spacing rows.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | Unmatched (691536; lanthanum-crown class) |
| L2 | Negative Meniscus | Unmatched (712525; lanthanum-crown class) |
| P | Negative Meniscus Resin Layer (1× Asph) | Unmatched (optical resin layer P; no glass-catalog identity) |
| L3 | Negative Meniscus | 487704 fluor-crown class (vendor-indeterminate) |
| L4 | Biconvex Positive | Unmatched (730262; dense-flint class) |
| L5 | Biconvex Positive (2× Asph) | BAC6 (HOYA legacy catalog equivalent; patent code 575560, supplier unspecified) |
| L6 | Negative Meniscus | Unmatched (907303; ultra-high-index flint class) |
| L7 | Positive Meniscus | 497816 ED fluorophosphate-crown class (vendor-indeterminate) |
| L8 | Biconvex Positive (2× Asph) | Unmatched (581465; barium-flint class; nearest public candidate J-BAF3, Δnd +0.00134, Δνd -0.02) |
| L9 | Biconvex Positive | 847238 dense-flint class (vendor-indeterminate) |
| L10 | Biconcave Negative | Unmatched (810331; lanthanum-flint class; nearest public candidate J-LASFH6, Δnd -0.00430, Δνd +0.24) |
| L11 | Biconvex Positive | 487704 fluor-crown class (vendor-indeterminate) |
| L12 | Biconcave Negative | K-LaSFn23 (SUMITA catalog equivalent; patent nd retained, production supplier unspecified) |