GB777756A - Microscope illumination system for wide ranges of aperture and illumination-field - Google Patents

Abstract

777,756. Microscopes. ZEISS-STIFTUNG, C., [trading as ZEISS, C., [Firm of ]]. Feb. 7. 1955 [Feb. 26, 1954], No. 3520/55. Class 97(1) To enable a miscroscope illumination system to be adjusted for objectives of differing focal length the elements of the condenser proper are fixed and further lenses are provided movable into the system at different planes between the illumination-field diaphgragm and the condenser proper so that an image of the light source is always formed at the aperture diaphragm of the condenser and an image of the illumination field diaphragm is formed at the object. Fig. 2b shows a system in which the fixed condenser lenses 1, 2, 3, 4, 5 alone give maximum aperture and a small field. To decrease the former and increase the latter a telescope 9, 10 and 11 is introduced between the field diaphragh L and the lenses 3, 4 and 5, the lens 9 forming an intermediate image of the diaphragm. To give further step-bystep changes in aperture and field the lens 10 may be omitted, the lens 9 being suitably adjusted in position, and then so adjusted on further change may be effected by replacing the negative lens 11 by another negative lens, and a further change by omitting the lens 11. Further examples are given for systems in which the fixed condenser elements alone give medium aperture and field and in which they give small aperture and maximum field, the necessary changes being effected by the insertion of suitable lenses.