JP H05-157964 A — Hiroshi Endo
| 9 ELEMENTS / 7 GROUPS |
| DESIGN f = 85.0 mm |
| DESIGN F/1.8 |
| ALL SPHERICAL |
Rear focus: only G2 (the L5-L6 cemented doublet, surfaces 10-12) moves, 11.19 mm toward the image from infinity to 0.85 m; G1, the stop, G3 and the image plane stay fixed. The patent prints only the infinity gaps, so the 0.85 m state is derived: it is the G2 position that brings an object 0.85 m from the image plane, Canon's published minimum focus distance, to paraxial focus. Gaps between the two states are interpolated linearly, so intermediate distance labels are estimates. The patent's own close-focus plots are labelled 0.8 m without stating where that distance is measured from.
| Element | Type | Glass |
|---|---|---|
| L1 | Biconvex Positive | LAL7 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L2 | Positive Meniscus | LAH66 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L3 | Positive Meniscus | LAL8 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L4 | Negative Meniscus | PBH1 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L5 | Positive Meniscus | PBH6 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L6 | Biconcave Negative | BSL7 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L7 | Biconcave Negative | PBH6 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L8 | Biconvex Positive | LAH53 (OHARA; coordinate equivalent; supplier unconfirmed) |
| L9 | Biconvex Positive | LAH66 (OHARA; coordinate equivalent; supplier unconfirmed) |