S-NPH7 which has negative dn/dT in the region of NPH and is ideal for polished lenses of Automotive cameras.
05.18.2018
S-NPH7 is an optical glass which has the smallest dn/dT in the region of NPH, high refractive indices and high dispersion. In the optical system of the Automotive camera lens, it’s common that the focal length is fixed. Cars are used in environments where the temperature change is large from below zero (in cold district) to 50 C or above (inside car in summer). When we make the design of optical system, considering refractive index fluctuations due to temperature change should be needed. Generally speaking, NPH glasses have positive dn/dT and the value of dn/dT is large at the positive side. But by making use of S-NPH7 which has large negative dn/dT number at the negative side, it’s expected that the refractive index fluctuations could be corrected efficiently in the optical system. In addition, S-NPH7 can be used for various applications such as lenses for Automotive cameras, as well as Projectors and Photographic interchangeable lenses.
| S-NPH7 | ||
| Eco Optical Glass | ○ | |
| Refractive Index nd | 1.77830 | |
| Abbe Number νd | 23.91 | |
| CTE α (10-7/℃) |
-30～70℃ | 109 |
| +100～300℃ | 130 | |
| Transformation Point Tg(°C) | 569 | |
| Yield Point At(°C) | 598 | |
| Coloring | λ80 | 420 |
| λ5 | 370 | |
| Chemical Resistance | RW(P) | 1 |
| RA(P) | 1 | |
| W(S) | 2 | |
| SR | 1.0 | |
| PR | 1.0 | |
| Specific Gravity | 3.30 | |
| Knoop Hardness Hk | 350〔4〕 | |
| Abrasion Aa | 448 | |
| Detail Catalog DATA | ||
| Available shapes | •pressing •saw cut center-less groundcylindrical blanks •cut blanks |
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Please consult us about available size and tolerance.