Patents by Inventor Keshav D. Sharma
Keshav D. Sharma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6914728Abstract: This invention relates to a microscope having an infinity-corrected objective and providing a flat field of view.Type: GrantFiled: December 5, 2002Date of Patent: July 5, 2005Assignee: Leica Microsystems Inc.Inventor: Keshav D. Sharma
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Patent number: 6882481Abstract: An arrangement of lenses for a 100×, oil immersion microscope objective is presented. The new configuration gives a flat field of view with diffraction limited performance over all the field. The new optical arrangement broadly includes eight lens elements including a positive power seventh lens element with the radius of curvature of the surface proximate to the object plane less than or approximately equal to the radius of curvature of the surface distal to the object plane, with the optical arrangement arrayed such that the distance from the first lens element to the second lens element is sufficient to reduce a ray height of a light ray and, in addition, arrayed such that the distance from the fifth lens element to the sixth lens element is sufficient to increase the ray height of the light ray entering the sixth lens element from the ray height of the light ray entering the first lens element.Type: GrantFiled: July 7, 2003Date of Patent: April 19, 2005Assignee: Leica Microsystems Inc.Inventor: Keshav D. Sharma
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Patent number: 6816248Abstract: A hand-held automatic refractometer comprises a linear scanned array having a plurality of photoelectric cells and an optical system for directing light onto the array, the particular photoelectric cells of the array which are illuminated by said light being determined by the index of refraction of a sample substance placed on a sample surface of a prism of the optical system. A reflective surface is arranged close to the array at an acute angle thereto for directing primary light from the sample-prism boundary to the array, and for redirecting stray reflected light from the array back onto the array. The disclosed refractometer has a compact design wherein the linear array extends in a direction substantially parallel to the prism sample surface. The prism is mounted in a housing and the sample surface faces upward to allow access through a sample well of the housing, while the array is mounted in the housing facing in a downward direction.Type: GrantFiled: April 26, 2001Date of Patent: November 9, 2004Assignee: Reichert, Inc.Inventors: Keshav D. Sharma, Kyle R. Bleyle
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Publication number: 20040109238Abstract: This invention relates to a microscope having an infinity-corrected objective and providing a flat field of view.Type: ApplicationFiled: December 5, 2002Publication date: June 10, 2004Applicant: Leica Microsystems Inc.Inventor: Keshav D. Sharma
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Patent number: 6734956Abstract: An optical configuration for measuring a difference in refractive index between a first sample and a second sample comprises partitioned first and second optical interfaces symmetrically illuminated by an illumination beam to provide first and second partial beams defined by the refractive index of the first and second samples, respectively. A linear scanned array is aligned in a meridional plane of the optical configuration for detection purposes, and an optical multiplexor is provided upstream of the linear scanned array for receiving the first and second partial beams and defining first and second optical channels carrying optical signal information corresponding to the first and second partial beams. The optical multiplexor switches between optical channels, such that the linear scanned array detects either the first or second optical channel at a given time. Thus, differential measurements are possible using a single linear array.Type: GrantFiled: May 6, 2002Date of Patent: May 11, 2004Assignee: Reichert, Inc.Inventors: Michael J. Byrne, Keshav D. Sharma, Robert C. Atkinson, Bruce R. Cordier
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Publication number: 20040036881Abstract: A method and apparatus for determining a characteristic of a substance is disclosed. The apparatus comprises a light source, a prism, a sensor chip located on the prism, focusing optics located between the light source and the prism, a detector, collimating optics located between the prism and the detector, and calculation means for determining the characteristic of the substance. The sensor chip comprises a metallic film and a transparent substance. The metallic film is operatively arranged to reflect light from the light source. The transparent substance comprises a material having an index of refraction matched to an index of refraction of the prism. The sensor chip is operatively arranged to receive a sample of the substance.Type: ApplicationFiled: August 22, 2002Publication date: February 26, 2004Applicant: Leica Microsystems Inc.Inventors: Keshav D. Sharma, Robert C. Atkinson, Richard W. Lesch
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Publication number: 20030206290Abstract: An optical configuration for measuring a difference in refractive index between a first sample and a second sample comprises partitioned first and second optical interfaces symmetrically illuminated by an illumination beam to provide first and second partial beams defined by the refractive index of the first and second samples, respectively. A linear scanned array is aligned in a meridional plane of the optical configuration for detection purposes, and an optical multiplexor is provided upstream of the linear scanned array for receiving the first and second partial beams and defining first and second optical channels carrying optical signal information corresponding to the first and second partial beams. The optical multiplexor switches between optical channels, such that the linear scanned array detects either the first or second optical channel at a given time. Thus, differential measurements are possible using a single linear array.Type: ApplicationFiled: May 6, 2002Publication date: November 6, 2003Applicant: Leica Microsystems Inc.Inventors: Michael J. Byrne, Keshav D. Sharma, Robert C. Atkinson, Bruce R. Cordier
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Publication number: 20030206291Abstract: An optical configuration for measuring a difference in refractive index between a first sample and a second sample comprises partitioned first and second optical interfaces symmetrically illuminated by an illumination beam to provide first and second partial beams defined by the refractive index of the first and second samples, respectively. First and second linear scanned arrays are positioned on opposite sides of a meridional plane of the optical configuration for respectively detecting the first and second partial beams. Thus, differential measurements are possible based on signal information from the arrays. Embodiments for critical angle and surface plasmon resonance refractive index measurements are disclosed. The disclosure also relates to methods for measuring a difference in refractive index between a first sample and a second sample in accordance with the described optical configuration embodiments.Type: ApplicationFiled: May 6, 2002Publication date: November 6, 2003Applicant: Leica Microsystems Inc.Inventors: Michael J. Byrne, Keshav D. Sharma, Robert C. Atkinson
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Publication number: 20020159050Abstract: A hand-held automatic refractometer comprises a linear scanned array having a plurality of photoelectric cells and an optical system for directing light onto the array, the particular photoelectric cells of the array which are illuminated by said light being determined by the index of refraction of a sample substance placed on a sample surface of a prism of the optical system. A reflective surface is arranged close to the array at an acute angle thereto for directing primary light from the sample-prism boundary to the array, and for redirecting stray reflected light from the array back onto the array. The disclosed refractometer has a compact design wherein the linear array extends in a direction substantially parallel to the prism sample surface. The prism is mounted in a housing and the sample surface faces upward to allow access through a sample well of the housing, while the array is mounted in the housing facing in a downward direction.Type: ApplicationFiled: April 26, 2001Publication date: October 31, 2002Applicant: Leica Microsystems Inc.Inventors: Keshav D. Sharma, Kyle R. Bleyle
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Patent number: 6172746Abstract: A transmitted light refractometer comprises an optical system having a movable mirror for redirecting light transmitted through a light-refracting sample to a beam splitter for dividing the light between first and second detection paths. The first detection path leads to an eyepiece whereby an operator may view an illumination boundary shadowline brought into the field of view of the eyepiece by adjusting the position of the movable mirror. The second detection path leads to a light-sensitive detector, preferably a linear scanned array, for generating signal information indicative of the location of the shadowline on the detector. An optical position sensor associated with the movable mirror includes a position detector providing signal information indicative of the position of the movable mirror.Type: GrantFiled: October 27, 1999Date of Patent: January 9, 2001Assignee: Leica Microsystems Inc.Inventors: Michael J. Byrne, Thomas E. Ryan, Kyle R. Bleyle, Keshav D. Sharma, Robert C. Atkinson, David J. Cash