JP 5857306 B2 — Katsuya Hirano, Eiichi Yasuda
| 19 ELEMENTS / 14 GROUPS |
| DESIGN f = 72–194 mm |
| DESIGN F/4.1 |
| ALL SPHERICAL |
| ESTIMATED G1Y INNER FOCUS TO 1 m |
ESTIMATED internal focus: only G1Y (L3–L4) moves, toward the object by 13.522 / 13.528 / 13.534 mm at the three zoom stations for a 1.0 m object-to-image distance. The patent identifies that group and plots 1 m states but prints no focus travel; these spacings are calculated. The front and rear gaps change equally in opposite directions; all other groups, the iris and the image plane stay fixed. Focus interpolates 33 calculated inverse-distance samples. Zoom still steps through the printed 72, 105 and 194 mm stations; its unmodeled intermediate cam would otherwise be up to 6.3 mm out of focus. Back focus stays at the derived 54.66 mm, and the stabilization doublet remains centred.
| Element | Type | Glass |
|---|---|---|
| L1 | Negative Meniscus | S-TIH6 (OHARA catalog equivalent; production supplier unspecified) |
| L2 | Positive Meniscus | S-PHM53 (OHARA catalog equivalent; production supplier unspecified) |
| L3 | Biconvex Positive | S-FPL51 (OHARA catalog equivalent; production supplier unspecified) |
| L4 | Biconvex Positive | S-FPL51 (OHARA catalog equivalent; production supplier unspecified) |
| L5 | Positive Meniscus | S-TIH53 (OHARA catalog equivalent; production supplier unspecified) |
| L6 | Biconcave Negative | L-BSL7 (OHARA catalog equivalent; production supplier unspecified) |
| L7 | Negative Meniscus | S-LAH65V (OHARA catalog equivalent; production supplier unspecified) |
| L8 | Positive Meniscus | S-TIH53 (OHARA catalog equivalent; production supplier unspecified) |
| L9 | Biconcave Negative | S-LAH55 (OHARA catalog equivalent; production supplier unspecified) |
| L10 | Biconvex Positive | S-LAL7 (OHARA catalog equivalent; production supplier unspecified) |
| L11 | Negative Meniscus | S-LAM66 (OHARA catalog equivalent; production supplier unspecified) |
| L12 | Positive Meniscus | FCD1 (HOYA catalog equivalent; production supplier unspecified) |
| L13 | Negative Meniscus | S-LAH60V (OHARA catalog equivalent; production supplier unspecified) |
| L14 | Positive Meniscus | S-FSL5 (OHARA catalog equivalent; production supplier unspecified) |
| L15 | Positive Meniscus | S-TIH53 (OHARA catalog equivalent; production supplier unspecified) |
| L16 | Biconcave Negative | S-LAM55 (OHARA catalog equivalent; production supplier unspecified) |
| L17 | Biconvex Positive | S-BSM25 (OHARA catalog equivalent; production supplier unspecified) |
| L18 | Negative Meniscus | S-TIH53 (OHARA catalog equivalent; production supplier unspecified) |
| L19 | Biconvex Positive | S-BAH27 (OHARA catalog equivalent; production supplier unspecified) |