GB360782A - Improvements in devices providing differently coloured illumination for microscopic objects - Google Patents

Abstract

360,782. Microscopes. ZEISS, C. [Firm of], Carl Zeiss-Strasse, Jena, Germany. March 12, 1931, No. 7616. Convention date, March 24, 1930. [Class 97 (i).] An illuminating appliance providing dark ground illumination of one colour and light ground illumination of a different colour consists of a condenser b provided with an iris diaphragm c, and colour filters for producing differently coloured lights in the central and outer parts of the pencil of illuminating rays. The filters are mounted in a pivoted support f below the condenser and comprise an annular red filter g surmounted by a smoked glass h, and a blue filter l mounted in a tube i which is fitted in the central aperture in the filter g. Directly beneath the filter l and immediately above a dispersing filter o of frosted glass is an iris diaphragm m and at the lower end of the tube i is an iris diaphragm p. The diaphragm p controls the brilliancy of illumination of the filter o and the diaphragm m controls the aperture of the said filter. The filter l may also be surmounted by a smoked glass r. Rays passing through the filter g and the condenser leave the latter at such an angle as to pass outside the front lens of the microscope objective, and therefore provide the dark ground illumination, while the light ground illumination is produced by the rays passing through the filter l.