US 5,899,585 — Hideki Ogawa
| 10 ELEMENTS / 10 GROUPS |
| COMPUTED EFL 28.9689-76.9612 mm |
| PATENT f/3.46-5.88 |
| 3-UNIT NEGATIVE-POSITIVE-NEGATIVE ZOOM |
| ALL-SPHERICAL |
| FRONT-UNIT FOCUS; NO FINITE-FOCUS RECONSTRUCTION |
NO_INTERNAL_RECONSTRUCTION: the patent identifies L1 front-unit focus, but no finite-focus spacings are published; 0.38 m is the rounded production MFD only.
| Element | Type | Glass |
|---|---|---|
| L11 | Positive Meniscus | S-BSL7 (OHARA equivalent; vendor unspecified) |
| L12 | Negative Meniscus | S-BAH27 (OHARA equivalent; vendor unspecified) |
| L13 | Biconcave Negative | S-BSM15 (OHARA equivalent; vendor unspecified) |
| L14 | Positive Meniscus | S-TIH14 (OHARA equivalent; vendor unspecified) |
| L21 | Biconvex Positive | S-BSM18 (OHARA equivalent; vendor unspecified) |
| L22 | Positive Meniscus | S-BAH11 (OHARA equivalent; vendor unspecified) |
| L23 | Biconcave Negative | S-TIH11 (OHARA equivalent; vendor unspecified) |
| L24 | Biconvex Positive | S-TIL25 (OHARA equivalent; vendor unspecified) |
| L31 | Biconcave Negative | S-BSM18 (OHARA equivalent; vendor unspecified) |
| L32 | Positive Meniscus | S-BAH11 (OHARA equivalent; vendor unspecified) |