CN 211826700 U, Example 1 — Liu Ruijun, Chen Baofeng
| 11 ELEMENTS / 10 GROUPS |
| DESIGN f = 23.44 mm |
| DESIGN F/1.4 |
| ALL SPHERICAL |
| INTERNAL FOCUS |
PUBLISHED — single-element internal focus: the negative G3 meniscus (Element 9) moves toward the image as focus shortens from infinity to the patent's 0.3 m state, which matches the marketed minimum focus distance (D1 1.00 → 3.76 mm; D2 4.43 → 1.88 mm). The printed D1 + D2 grows by 0.21 mm although G2 and G4 are fixed; the printed spacings are kept.
| Element | Type | Glass |
|---|---|---|
| L11 | Negative Meniscus | Unmatched (nd 1.88, νd 40.79; coarse patent coordinates) |
| L12 | Biconvex Positive | Unmatched (printed nd 1.85 corrected to 1.83, νd 42.72; coarse patent coordinates) |
| L13 | Positive Meniscus | Unmatched (nd 1.85, νd 36.59; coarse patent coordinates) |
| L14 | Positive Meniscus | Unmatched (nd 1.51, νd 81.59; coarse patent coordinates) |
| L15 | Negative Meniscus | Unmatched (nd 1.48, νd 70.44; coarse patent coordinates) |
| L21 | Biconcave Negative | Unmatched (nd 1.85, νd 23.78; coarse patent coordinates) |
| L22 | Biconvex Positive | Unmatched (nd 1.73, νd 54.67; coarse patent coordinates) |
| L23 | Biconvex Positive | Unmatched (nd 1.93, νd 20.88; coarse patent coordinates) |
| L31 | Negative Meniscus | Unmatched (nd 1.75, νd 28.30; coarse patent coordinates) |
| L41 | Biconvex Positive | Unmatched (nd 1.73, νd 54.67; coarse patent coordinates) |
| L42 | Negative Meniscus | Unmatched (nd 1.85, νd 23.78; coarse patent coordinates) |