JP 2020-190696 A, Numerical Example 1 — Yoshiyuki Taki
| 12 ELEMENTS / 9 GROUPS |
| DESIGN f = 17.49–38.83 mm |
| DESIGN F/4.1 |
| 3 ASPHERICAL SURFACES / 3 ELEMENTS |
Inner focus (¶0034, Fig. 1): the Lf subgroup (E2 with its replica layer, and E3) moves objectward inside group L1 while E1 stays fixed; D2 shrinks and D7 grows by the same amount. The patent prints no close-focus data, so the focus states are solved for Canon's 0.28 m minimum focus distance (object to image) with the image plane fixed. Lf travels 4.07 mm at 17.49 mm, 3.95 mm at 23.99 and 25.78 mm and 4.07 mm at 38.83 mm, giving about 0.24× at the tele end.
| Element | Type | Glass |
|---|---|---|
| E1 | Negative Meniscus (1× Asph) | Unmatched (1.58373/59.4 glass-moldable crown; S-BAL42/L-BAL42 class) |
| R1 | Aspherical Resin Layer | Unmatched (replica resin, 1.52421/51.4) |
| E2 | Biconcave Negative | S-LAH66 (OHARA) |
| E3 | Positive Meniscus | S-NPH53 (OHARA) |
| E4 | Negative Meniscus | S-TIH10 (OHARA) |
| E5 | Biconvex Positive | S-BSL7 (OHARA) |
| E6 | Biconvex Positive | S-LAL12 (OHARA) |
| E7 | Biconcave Negative | S-LAL10 (OHARA) |
| E8 | Biconcave Negative | S-BSM22 (OHARA) |
| E9 | Positive Meniscus | S-TIH6 (OHARA) |
| E10 | Biconvex Positive | S-FPL53 (OHARA) |
| R2 | Aspherical Resin Layer | Unmatched (replica resin, 1.52421/51.4) |
| E11 | Biconcave Negative | S-LAH60 (OHARA) |
| E12 | Biconvex Positive | S-FSL5 (OHARA) |