| 单词 | focal surface |
| 释义 | > as lemmasfocal surface focal surface n. (a) Geometry a surface formed by the centres of curvature of a surface; = evolute n. 1a; (b) Optics an imaginary curved (usually spherical) surface on which initially parallel rays come to a focus after passing through a given lens or other optical system, and on which (in the case of visible light) the images of distant objects would be formed.In the latter sense, a focal surface with no curvature is a focal plane. ΘΚΠ the world > relative properties > number > geometry > curve > [noun] > locus locus1675 evolute1704 place1704 trajectory1795 syntractory1820 focal surface1828 synharmonic1850 syntractrix1852 pedal1862 umbilical focal conic1862 umbilical focal conic1862 stigmatic1863 synchronism1867 synchronous curve1867 Steinerian1873 tac-locus1873 strophoid1880 orthoptic locus1882 strophoidal1908 hypercycle1909 1828 Trans. Royal Irish Acad. 15 Science 128 Contact of the third order, between the given mirror and its osculating focal surface. 1893 Proc. Royal Soc. 1892–3 52 408 Any want of definition at the margin will be chiefly due to curvature of the focal surface. 1912 Publ. Astron. Observatory Univ. Mich. 1 39/1 Plaskett has found this lens to be remarkably free from spherical aberration over a wide range of its unusually flat focal surface. 1922 F. Woods Higher Geom. iv. xvii. 338 Any line of the congruence is tangent to the focal surface. 2001 J. Gallier Geom. Methods & Applic. 651 The focal surfaces Y and Z are generated by the lines of strictions of the developable surfaces generated by the normals to the lines of curvatures. 2003 N. James & G. North Observing Comets vii. 151 The film must be held against a specially shaped focal plate so that it forms the correct shape to match the focal surface. < as lemmas |
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