US 2021/0231927 A1 — Daiki Kawamura, Michio Cho
| 12 elements / 9 groups |
| 1 aspherical element (2 aspherical surfaces) |
| 2 ED elements |
| Inner focus (G2 moves) |
| f = 49.549 mm FNo = 1.03 2ω = 31.4° |
Patent Example 3: G2 moves 4.441 mm toward the object; G1 and stop remain fixed. Source close focus is 0.700 m from the sensor, or 0.699 m from the modeled air-equivalent image plane. Intermediate movement is interpolated.
| Element | Type | Glass |
|---|---|---|
| L1a | Biconcave Negative | S-TIL2 (catalog-compatible model; supplier unspecified) |
| L1b | Biconvex Positive | 593686 ED class; J-PSKH1 catalog spectral proxy (patent dPgF retained) |
| L1c | Positive Meniscus | 593686 ED class; J-PSKH1 catalog spectral proxy (patent dPgF retained) |
| L1d | Positive Meniscus | S-NPH3 (catalog-compatible model; supplier unspecified) |
| L1e | Positive Meniscus | LaK (nd=1.788, νd=47.5) |
| L1f | Negative Meniscus | 893204 NPH class; S-NPH4 catalog spectral proxy (production supplier unspecified) |
| L1g | Negative Meniscus | SF/NPH (nd=1.808, νd=22.8) |
| L2a | Neg. Meniscus (2× Asph) | NbF/SF (nd=1.689, νd=31.2) |
| L2b | Biconvex Positive | LaF (nd=1.883, νd=39.2) |
| L2c | Biconcave Negative | NbF (nd=1.699, νd=30.1) |
| L2d | Biconvex Positive | LaF (nd=1.883, νd=39.2) |
| L2e | Negative Meniscus | TiF/F (nd=1.620, νd=36.4) |