US 2019/0250367 A1, Example 1 — Minoru Murayama
| 15 elements / 9 groups |
| f = 49.57 mm design |
| F1.45 design / F1.4 nominal |
| 2ω = 47° |
| 2 aspherical surfaces |
Rear-group unit focusing. The first group is stationary; the complete second group translates toward the object. Patent Example 1 changes D11 from 10.407 mm to 1.012 mm and D25 (last lens surface to the cover plate) from 37.310 mm to 46.706 mm.
| Element | Type | Glass |
|---|---|---|
| L11 | Weak Biconvex Positive | F5-class dense flint (HOYA E-F5 / Schott F-type equivalent) |
| L12 | Biconcave Negative | S-NBM51 / N-KZFS4 class (613443) |
| L13 | Biconvex Positive | TAFD35 (HOYA, 911353; patent rounds νd to 35.2) |
| L14 | Negative Meniscus | S-NBM51 / N-KZFS4 class (613443) |
| L21 | Biconcave Negative | Niobium dense flint class (OHARA S-NBH8 class) |
| L22 | Biconvex Positive | S-PHM52 (OHARA, 618634) |
| L23 | Biconvex Positive | S-LAH55 / TAFD5F class (835427) |
| L31 | Positive Meniscus | OHARA S-LAH89 class |
| L32 | Biconvex Positive | OHARA S-FPM2 / ED fluorophosphate class |
| L33 | Negative Meniscus | F5-class dense flint (HOYA E-F5 / Schott F-type equivalent) |
| L41 | Negative Meniscus | F5-class dense flint (HOYA E-F5 / Schott F-type equivalent) |
| L42 | Biconvex Positive | OHARA S-FPM2 / ED fluorophosphate class |
| L43 | Positive Meniscus | S-LAH58 / TAFD30 class (883408) |
| L44 | Biconcave Negative | OHARA S-TIL26 class |
| L51 | Biconvex Positive (2× Asph) | 773495 - moldable lanthanum crown class (patent nd=1.77250, νd=49.5) |