US 2001/0030812 A1 — Akiko Furuta
| 18-35mm f/3.5-4.5 |
| 11 ELEMENTS / 8 GROUPS |
| 1 COMPOUND ASPHERICAL + 1 ED ELEMENT |
| INTERNAL FOCUS • 0.33 m MFD |
PUBLISHED inner-focus states: G2a translates imageward while d9+d12 is conserved at each zoom position; near rows are labeled R=0.33 m. The printed Example 2 d0 row is internally inconsistent with the patent's object-to-image definition of R (d0 + S1-to-image track is about 323.330 mm), so d0 is not used to reconstruct movement.
| Element | Type | Glass |
|---|---|---|
| L11 | Negative Meniscus | 795453 class (vendor unspecified) |
| L12c | Compound Asphere Layer | Unmatched (compound-asphere layer; material not identified) |
| L12 | Negative Meniscus Substrate | 795453 class (vendor unspecified) |
| L13 | Biconcave Negative | H-LaF3B catalog equivalent (patent 744448; production supplier unspecified) |
| L14 | Biconvex Positive | J-LAFH3 catalog equivalent (patent 795286; production supplier unspecified) |
| L21 | Negative Meniscus | 788474 class (vendor unspecified) |
| L22 | Biconvex Positive | 501564 class (vendor unspecified) |
| L23 | Biconvex Positive | BAK2 catalog equivalent (patent 540595; production supplier unspecified) |
| L24 | Biconcave Negative | 795453 class (vendor unspecified) |
| L25 | Negative Meniscus | NBFD10 catalog equivalent (patent 834374; production supplier unspecified) |
| L26 | Biconvex Positive | J-FKH1 catalog equivalent (patent 498825; production supplier unspecified) |
| L27 | Biconvex Positive | BAK2 catalog equivalent (patent 540595; production supplier unspecified) |