US 2018/0164556 A1 — Takahiko Ohishi
| 16 ELEMENTS / 11 GROUPS |
| 11–18 mm MARKETING / 11.25–17.70 mm DESIGN |
| F/2.8 CONSTANT |
| 2ω = 105.2–76.8° (PATENT) |
| 4 ASPHERICAL SURFACES |
| CONSTRAINED INTERNAL-FOCUS RECONSTRUCTION |
CONSTRAINED_RECONSTRUCTION: the patent-published infinity zoom states are transcribed exactly. The G2 front subgroup L21/L22/L23 (surfaces 11–15), identified as a permissible focusing group in patent paragraph 0067, translates imageward while D10 + D15 remains constant at each zoom station. Close endpoints are code-solved for a 0.30 m object distance referenced to the fixed image plane; the tele state gives 0.09791× paraxial magnification, consistent with the rounded 0.10× production specification. No other floating motion is inferred.
| Element | Type | Glass |
|---|---|---|
| L11 | Negative Meniscus (1× Asph) | 694532 class (vendor unproven) |
| L12g | Negative Meniscus | Unmatched (780509 class; no defensible current-catalog identity recovered) |
| L12r | Positive Meniscus (1× Asph) | Synthetic resin layer (patent-defined hybrid asphere) |
| L13 | Biconcave Negative | Unmatched (810372 class; no defensible current-catalog identity recovered) |
| L14 | Biconvex Positive | E-FEL1 (HOYA catalog equivalent; production supplier unspecified; patent 547460) |
| L15 | Negative Meniscus | Unmatched (850440 class; no defensible current-catalog identity recovered) |
| L21 | Biconvex Positive | 567428 class (vendor unproven) |
| L22 | Negative Meniscus | 816466 class (vendor unproven) |
| L23 | Biconvex Positive | Unmatched (564463 class; no defensible current-catalog identity recovered) |
| L24 | Positive Meniscus | 497816 ED-crown class (vendor unproven) |
| L31 | Biconcave Negative | 804466 class (vendor unproven) |
| L32 | Positive Meniscus | 847238 dense-flint class (vendor unproven) |
| L41 | Biconvex Positive | 439950 extreme-low-dispersion crown class (vendor unproven) |
| L42 | Biconcave Negative | 847238 dense-flint class (vendor unproven) |
| L43 | Biconvex Positive | 497816 ED-crown class (vendor unproven) |
| L44 | Positive Meniscus (2× Asph) | 516641 crown class (vendor unproven) |