Multipowered micro-objective group having common means for aberration correction

Claim 2

A multipowered micro-objective lens system having a range of power comparable to standard micro-objectives for forming a superior image of an object which is viewed by an aligned eyepiece, the system comprising; a plurality of semiobjectives which are interchangeably mounted in a microscope nosepiece for individual optical alignment on the optical axis of the microscope, the semiobjectives having individual magnifications ranging from low to high values and having a common finite object-to-image distance per se, the focal lengths of the higher powered semiobjectives being increased to reduce the Petzval sum of the higher powered semiobjectives without necessitating a change in overall power or object-to-image distance, the object-to-image distance and the magnifications of the semiobjectives being less than the object-to-image distance and magnifications of standard micro-objectives, the lower powered semiobjectives having an amount of deliberately introduced lateral color aberration approximately the same as the inherent lateral color aberration in the higher powered semiobjectives, an aberration corrector lens system including a negative lens system aligned at a fixed axial position on the optical axis of the microscope rearwardly of said semiobjectives and which substantially focuses the primary image of the semiobjectives at infinity and a telescope objective system which forms an image at the eyepiece focal plane, the telescope objective system being the rearmost lens component of the micro-objective lens system wherein said aberration corrector lens system is used in common with each individual semiobjective when the semiobjective is in optical alignment on the optical axis of the microscope, the negative lens system per se containing amounts of compensating corrective aberrations therein which in individual combination with each one of the semiobjectives reduces the cumulative aberrations in the image wIth regard to Petzval sum, coma, and astigmatism, which are produced by the complete micro-objective, the aberrations remaining in the image being approximately the same for each of the plurality of semiobjectives when in combination with the negative lens system throughout the complete range of magnification, and the telescope objective lens system per se being constructed to substantially eliminate the residual lateral chromatic aberration of the first said lens system.

Claim 3

A multipowered micro-objective lens system having a range of power comparable to standard micro-objectives for forming a superior image of an object when viewed through an eyepiece lens system, the system comprising: a plurality of semiobjectives which are interchangeably mounted in a microscope nosepiece for individual optical alignment on the optical axis of the microscope, the semiobjectives having individual magnifications ranging from low to high values and forming an image at a common finitely positioned intermediate image plane per se, the focal lengths of the higher powered semiobjectives being increased to reduce the undercorrected field curvature aberration of the higher powered semiobjectives without necessitating a change in overall power or object-to-image distance of the micro-objective, the object-to-image distance of the semiobjectives per se being less than the object-to-image distance of standard micro-objectives, each of the semiobjectives being undercorrected with regard to field curvature, coma, and astigmatism, the lower powered semiobjectives having an amount of deliberate overcorrection for lateral color approximately the same as the inherent overcorrection for lateral color in the higher powered semiobjectives, an aberration corrector lens system including a front negative doublet lens member which substantially focuses the primary image of the semiobjectives at infinity and a rearward positive singlet telescope objective lens member aligned therewith at a focusable axial position on the optical axis of the microscope and focused at the focal plane of said eyepiece lens system, said intermediate image plane being located intermediate of the aberration corrector lens system, the aberration corrector lens system being the rearmost component of the micro-objective lens system and acting in common with each individual semiobjective which is in optical alignment on the optical axis of the microscope, the negative doublet lens member containing amounts of overcorrected aberrations therein which in individual combination with each one of the semiobjectives reduces the cumulative aberrations in the image with regard to field curvature, coma and astigmatism which are produced by the complete micro-objective, the aberrations remaining in the image being substantially identical for each of the plurality of semiobjectives when in combination with said negative member, said positive singlet lens member being chromatically corrected to substantially eliminate lateral color aberration whereby a standard eyepiece lens system may be used in conjunction with all of the semiobjectives and the product of the magnification of any selected one of the semiobjectives multiplied by the magnification of the aberration corrector lens system being approximately the same as the magnification of a standard micro-objective having a numerical aperture comparable to the selected combination.

Claim 4

A multipowered micro-objective lens system having a range of power comparable to standard micro-objectives for forming a superior image of an object when viewed through an eyepiece lens system, the system comprising: a plurality of semiobjectives which are interchangeably mounted in a microscope nosepiece for individual optical alignment on the optical axis of the microscope, the semiobjectives having individual magnifications ranging from low to high values and forming an image at a common finitely positioned intermediate image plane per se, the focal lengths of the higher powered semiobjectives being increased to reduce the undercorrected field curvature aberration of the higher powered semiobjectives without necessitating a change in overall power or object-to-image distance of the micro-objective, the object-to-image distance of the semiobjectives per se being less than the object-to-image distance of standard micro-objectives, each of the semiobjectives being undercorrected with regard to field curvature, coma, and astigmatism, the lower powered semiobjectives having an amount of deliberate overcorrection for lateral color approximately the same as the inherent overcorrection for lateral color in the higher powered semiobjectives, an aberration corrector lens system including a front negative doublet lens member which substantially focuses the primary image of the semiobjectives at infinity and a rearward positive singlet telescope objective lens member aligned therewith at a focusable axial position on the optical axis of the microscope and focused at the focal plane of said eyepiece lens system, said intermediate image plane being located intermediate of the aberration corrector lens system, the aberration corrector lens system being the rearmost component of the micro-objective lens system and acting in common with each individual semiobjective which is in optical alignment on the optical axis of the microscope, the negative doublet lens member containing amounts of overcorrected aberrations therein which in individual combination with each one of the semiobjectives reduces the cumulative aberrations in the image with regard to field curvature, coma and astigmatism which are produced by the complete micro-objective, the aberrations remaining in the image being substantially identical for each of the plurality of semiobjectives when in combination with said negative member, said positive singlet lens member being chromatically corrected to substantially eliminate lateral color aberration whereby a standard eyepiece lens system may be used in conjunction with all of the semiobjectives and the product of the magnification of any selected one of the semiobjectives multiplied by the magnification of the aberration corrector lens system being approximately the same as the magnification of a standard micro-objective having a numerical aperture comparable to the selected combination.

Claim 5

A microscope objective system of superior image quality including the combination of a plurality of semiobjectives which are interchangeably mounted in a rotatable nosepiece for optical alignment on the optical axis of the microscope, said semiobjectives having positive focal lengths and having individual magnifications ranging from low to high values, said semiobjectives having a common finite object-to-image distance per se, the magnification of each said semiobjective being substantially one-fifth of the magnification of said complete objective system, said semiobjecTives per se being undercorrected lens systems with regard to field curvature, coma, and astigmatism, and being overcorrected for lateral color, an aberration corrector lens system comprising a front negative lens member aligned at a fixed axial position on the optical axis rearwardly of said semiobjectives and focused substantially at infinity and further comprising a coaxial focusable rear telescope lens member, said aberration corrector lens system serving as a rear component which is common to each of said plurality of semiobjectives when aligned therewith and effecting an image magnification of substantially 5 X , said aberration corrector lens system further having a compensating amount of corrective aberration constructed therein which in combination individually with each of said semiobjectives reduces to minimum values the cumulative aberrations in the image with regard to field curvature, coma, and astigmatism, which are produced by the entire optical system throughout the complete range of magnification, and said rear positive lens member having such an Abbe number value that the residual lateral chromatism of said image is reduced substantially to zero whereby standard commercial eyepieces may be used to view said image.

Claim 6

A microscope objective system of superior image quality including the combination of a plurality of semiobjectives which are interchangeably mounted in a rotatable nosepiece for optical alignment on the optical axis of the microscope, said semiobjectives having positive focal lengths and having individual magnifications ranging from low to high values, said semiobjectives having a common finite object-to-image distance per se, the magnification of each said semiobjective being substantially one-fifth of the magnification of said complete objective system, said semiobjecTives per se being undercorrected lens systems with regard to field curvature, coma, and astigmatism, and being overcorrected for lateral color, an aberration corrector lens system comprising a front negative lens member aligned at a fixed axial position on the optical axis rearwardly of said semiobjectives and focused substantially at infinity and further comprising a coaxial focusable rear telescope lens member, said aberration corrector lens system serving as a rear component which is common to each of said plurality of semiobjectives when aligned therewith and effecting an image magnification of substantially 5 X , said aberration corrector lens system further having a compensating amount of corrective aberration constructed therein which in combination individually with each of said semiobjectives reduces to minimum values the cumulative aberrations in the image with regard to field curvature, coma, and astigmatism, which are produced by the entire optical system throughout the complete range of magnification, and said rear positive lens member having such an Abbe number value that the residual lateral chromatism of said image is reduced substantially to zero whereby standard commercial eyepieces may be used to view said image.