US 2006/0007559 A1 — Haruo Sato
| 7 ELEMENTS / 5 GROUPS |
| 18-55mm f/3.5-5.6 (MARKETED) |
| 18.5-53.5mm f/3.56-5.90 (EXAMPLE 4) |
| 1 ED / 1 ASPHERICAL ELEMENT (PRODUCTION) |
PUBLISHED Example 4 focus: G1 translates toward the object while G2-to-image spacing is unchanged at each zoom position; closest endpoints solve to about 0.250 m from the focal plane. Production MFD 0.28 m is not used to alter the patent model.
| Element | Type | Glass |
|---|---|---|
| L1g | Negative Meniscus | 773496 class (vendor ambiguous; patent nd=1.772500, vd=49.61) |
| L1r | Negative Meniscus (1x Asph) | Unmatched (aspheric resin; trade name unpublished; patent nd=1.553890, vd=38.09) |
| L1p | Positive Meniscus | 861231 dense-flint class (HIKARI J-SFH2 is a close catalog equivalent; identity inferred) |
| L2a | Biconvex Positive | 497816 low-dispersion class (vendor/composition ambiguous) |
| L2ap | Biconvex Positive | 517641 crown class (vendor ambiguous; BK7-family coordinates) |
| L2an | Biconcave Negative | 773496 class (vendor ambiguous; patent nd=1.772500, vd=49.61) |
| Lbn | Negative Meniscus | 834372 high-index class (vendor/composition ambiguous) |
| Lbp | Biconvex Positive | 517641 crown class (vendor ambiguous; BK7-family coordinates) |