EP 4 174 551 A1 — Hiroki Ebe, Shunji Iwamoto
| 13 ELEMENTS / 11 GROUPS |
| 15-30mm MARKETING / 15.45-29.15mm PATENT |
| f/4.5-6.3 MARKETING / f/4.60-6.36 MODEL |
| 2 ASPHERICAL SURFACES / 2 UD-CLASS ELEMENTS |
CONSTRAINED_RECONSTRUCTION: patent ¶0047 identifies L3 (surfaces 20-21) as the focusing unit but publishes no finite-focus spacing table. Close-focus D19/D21 values are code-solved for Canon's 0.280 m AF MFD by translating L3 toward the image and conserving D19+D21=11.86 mm at every zoom state. The 0.128 m / 0.52× 15 mm manual-focus special state is not modeled across the zoom range.
| Element | Type | Glass |
|---|---|---|
| E1 | Negative Meniscus | 001291 — high-index lanthanum-flint class (vendor unresolved) |
| E2 | Negative Meniscus | 900374 — high-index lanthanum-flint class (vendor unresolved) |
| E3 | Biconcave Negative | 497815 — very-low-dispersion fluorophosphate-crown / UD-like class (vendor unresolved) |
| E4 | Biconvex Positive | 806333 — dense high-index flint class (vendor unresolved) |
| E5 | Biconvex Positive | 639449 — barium-flint class (vendor unresolved) |
| E6 | Negative Meniscus | 804465 — lanthanum-crown class (vendor unresolved) |
| E7 | Biconvex Positive | 713539 — lanthanum-crown class (vendor unresolved) |
| E8 | Positive Meniscus | 487702 — low-index crown class (vendor unresolved) |
| E9 | Negative Meniscus | 900374 — high-index lanthanum-flint class (vendor unresolved) |
| E10 | Biconvex Positive | 497815 — very-low-dispersion fluorophosphate-crown / UD-like class (vendor unresolved) |
| E11 | Negative Meniscus | 801350 — lanthanum-flint class (vendor unresolved) |
| E12 | Positive Meniscus (2× Asph) | Unmatched (PMo optical-resin class; production-correlation inference) |
| E13 | Positive Meniscus | 804465 — lanthanum-crown class (vendor unresolved) |