CN 209606699 U, Example 1 — Liu Ruijun, Chen Baofeng
| 12 ELEMENTS / 9 GROUPS |
| COMPUTED f = 20.31 mm |
| DESIGN F/1.8 |
| 2 ASPHERICAL SURFACES / 1 ELEMENT |
Infinity focus only. The patent states that G1 and G2 stay fixed while the rear group G3 moves to focus, but it prints no travel or near-focus spacings, so no near state is modeled. The marketed 0.25 m minimum focus distance is catalog data only.
| Element | Type | Glass |
|---|---|---|
| L11 | Negative Meniscus | Unmatched (high-index crown; rounded patent coordinates) |
| L12 | Negative Meniscus | Unmatched (dense flint; rounded patent coordinates) |
| L13 | Biconvex Positive | Unmatched (high-index flint; rounded patent coordinates) |
| L14 | Biconcave Negative | Unmatched (low-dispersion crown; rounded patent coordinates) |
| L21 | Positive Meniscus | Unmatched (high-index flint; rounded patent coordinates) |
| L22 | Positive Meniscus | Unmatched (low-dispersion crown; rounded patent coordinates) |
| L31 | Biconvex Positive | Unmatched (low-dispersion crown; rounded patent coordinates) |
| L32 | Biconcave Negative | Unmatched (dense flint; rounded patent coordinates) |
| L33 | Biconvex Positive | Unmatched (low-dispersion crown; rounded patent coordinates) |
| L34 | Biconvex Positive | Unmatched (high-index flint; rounded patent coordinates) |
| L35 | Biconcave Negative | Unmatched (dense flint; rounded patent coordinates) |
| L36 | Biconcave Negative (Asph) | Unmatched (crown; rounded patent coordinates) |