TUBE SHIELD LENS UNIT

摘要

A tube lens unit for microscopes with achromatically corrective effect for the use with objectives with infinite image distance and achromatic residual errors. The tube lens unit includes of at least two lenses with the properties:;nP<1.50 and vP<71;nN<1.66 and vN<37,;wherein nP and nN signify the refractive index (ne) at a wavelength of 546 nm for a positive and negative lens each, and vP and vN signify the Abbe number (ve) at a wavelength of 546 nm for a positive and negative lens each, and the beam paths are characterized by the conditions:;|δA|<0.60 and |δB|<0.30,;wherein δA signifies the variation of the aperture beam and δB signifies the variation of the main beam while passing through the surfaces of the lenses.

主权项

1. A tube lens unit for a microscope with achromatically corrective effect for the use with objectives with infinite image distance and achromatic residual errors, the tube lens unit including at least two lenses with the properties
nP<1.50 and vP<71 nN<1.66 and vN<37,wherein nP and nN signify the refractive index (ne) at a wavelength of 546 nm for a positive and negative lens each, and vP and vN signify the Abbe number (ve) at a wavelength of 546 nm (WL2) for a positive and negative lens each, and the beam paths are characterized by the conditions:
|δA|<0.60 and |δB|<0.30,wherein δA signifies the variation of the aperture beam as penetration heights for a diameter of the entrance pupil (EP) of 17.55 mm while passing through the surfaces of the lenses and δB signifies the variation of the main beam as penetration heights for an incidence angle w=3.23 degrees while passing through the surfaces of the lenses.