| 摘要 |
701,829. Phase contrast microscopy. LEITZ GES., E. Sept. 12, 1951 [Sept. 15, 1950]. No. 21464/51. Class 97(1) The phase contrast microscope claimed in Specification 665,944 is modified by the arrangement of an optical dispersing member between the condenser for focusing the annular base ' of illumination, and the object, so as to form an annular spectrum in the phase plate, the thickness of the latter varying radially. As shown the illuminating beam 1 after passing a filter 2 permeable to two, three or more ranges of the spectrum, is concentrated to a narrow annular base 4 by a condenser 3 and is then dispersed by a transparent cone 8 to be focused on the phase plate 7 by the objective 6 to form thereon a series of concentric coloured rings. The light diffracted by the object 5 passes through the central aperture of the phase plate 7. The thickness of the phase plate may vary continuously radially or in steps which themselves may be of varying thicknesses, and the thicknesses may be such that the. phase alteration by the plate amounts to the same fraotum of the respective wavelengths of the spectral groups. The cone 8 may be replaced by a chromatically uncorrected lens. Specification 648,801 also is referred to. |
