JP S54-55424 A, Example 1 — Toshiko Shimokura
| 5 ELEMENTS / 5 GROUPS |
| DESIGN f = 200 mm |
| DESIGN F/4 |
| ALL SPHERICAL |
| TELEPHOTO RATIO 0.809 |
The patent prints the infinity state only, so the geometry is static and no focus motion is modeled. The 2.5 m close-focus distance is the production lens's published figure, not a patent state. The image plane is the printed back focus, 52.2 mm behind the last surface. Semi-diameters are inferred from the patent figure; the stop position is printed and its radius follows from F/4.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | S-BSL7 (OHARA catalog equivalent; production supplier unspecified) |
| L2 | Biconcave Negative | S-TIH4 (OHARA catalog equivalent; production supplier unspecified) |
| L3 | Positive Meniscus | S-BSL7 (OHARA catalog equivalent; production supplier unspecified) |
| L4 | Negative Meniscus | S-LAH66 (OHARA catalog equivalent; production supplier unspecified) |
| L5 | Biconvex Positive | S-TIH6 (OHARA catalog equivalent; production supplier unspecified) |