Patents by Inventor Adolf Friedrich Fercher

Adolf Friedrich Fercher 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).

  • Patent number: 11317799
    Abstract: Measurement of intraocular lengths by dual-beam Fourier low-coherence interferometry on the basis of Fresnel-zone-type space-time domain interferograms of the Purkinje-Sanson reflexes. The eye is illuminated by parallel, monochromatic dual beams having wavelengths which differ in temporal sequence. Wavelength spectra of space-time domain interferograms are imaged onto a photodetector array and registered. Viewing direction and position of the eye are fixed by optical aids and are monitored by acoustic and optical aids. A zoom optical unit in the output beam of the ophthalmological interferometer makes it possible, by simple focusing, to image virtual Fresnel-zone-type space-time domain interferograms from contrast-optimized positions onto the photodetector array or onto an image intensifier that is arranged in front of the photodetector array such that the position-dependent size change of the space-time domain interferograms is compensated by the scale change of this imaging.
    Type: Grant
    Filed: May 2, 2017
    Date of Patent: May 3, 2022
    Assignee: Carl Zeiss Meditec AG
    Inventor: Adolf Friedrich Fercher
  • Publication number: 20200323429
    Abstract: Measurement of intraocular lengths by dual-beam Fourier low-coherence interferometry on the basis of Fresnel-zone-type space-time domain interferograms of the Purkinje-Sanson reflexes. The eye is illuminated by parallel, monochromatic dual beams having wavelengths which differ in temporal sequence. Wavelength spectra of space-time domain interferograms are imaged onto a photodetector array and registered. Viewing direction and position of the eye are fixed by optical aids and are monitored by acoustic and optical aids. A zoom optical unit in the output beam of the ophthalmological interferometer makes it possible, by simple focusing, to image virtual Fresnel-zone-type space-time domain interferograms from contrast-optimized positions onto the photodetector array or onto an image intensifier that is arranged in front of the photodetector array such that the position-dependent size change of the space-time domain interferograms is compensated by the scale change of this imaging.
    Type: Application
    Filed: May 2, 2017
    Publication date: October 15, 2020
    Applicant: Carl Zeiss Meditec AG
    Inventor: Adolf Friedrich FERCHER
  • Patent number: 8534838
    Abstract: A device for performing distance measurements on an eye. The device includes an interferometer, focuses at least one measurement beam records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing the focus in the eye or for varying a polarization state of the measurement beam and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and actuates the adjustment apparatus for displacing the position of the focus or for varying the polarization while recording the backscattered radiation from which the control apparatus generates the A-scan individual signals is being recorded.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: September 17, 2013
    Assignee: Carl Zeiss Meditec AG
    Inventors: Roland Barth, Roland Bergner, Wilfried Bissmann, Rudolf Murai von Buenau, Martin Hacker, Ingo Koschmieder, Adolf Friedrich Fercher, Branislav Grajciar, Ralf Ebersbach
  • Patent number: 8437008
    Abstract: A device for the interferometric measurement of a sample, in particular the eye, including an interferometer arrangement with a first measurement beam path, through which a measurement beam falls onto the sample, and a first reference beam path, through which a reference beam runs, which is applied to the measuring beam for interference. The interferometer arrangement includes a second measuring beam path and/or second reference beam path. The optical path lengths of the second measuring beam path and/or second reference beam path are different from one of the first beam paths. The wave length difference is selected according to a distance of two measuring areas which are arranged at a distance in the depth direction of the sample.
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: May 7, 2013
    Assignee: Carl Zeiss Meditec AG
    Inventors: Adolf Friedrich Fercher, Rainer Leitgeb
  • Publication number: 20110292395
    Abstract: A device for the interferometric measurement of a sample, in particular the eye, including an interferometer arrangement with a first measurement beam path, through which a measurement beam falls onto the sample, and a first reference beam path, through which a reference beam runs, which is applied to the measuring beam for interference. The interferometer arrangement includes a second measuring beam path and/or second reference beam path. The optical path lengths of the second measuring beam path and/or second reference beam path are different from one of the first beam paths. The wave length difference is selected according to a distance of two measuring areas which are arranged at a distance in the depth direction of the sample.
    Type: Application
    Filed: July 18, 2011
    Publication date: December 1, 2011
    Applicant: Carl Zeiss Meditec AG
    Inventors: Adolf Friedrich FERCHER, Rainer LEITGEB
  • Patent number: 7982881
    Abstract: A device for the interferometric measurement of a sample, in particular the eye, including an interferometer arrangement with a first measurement beam path, through which a measurement beam falls onto the sample, and a first reference beam path, through which a reference beam runs, which is applied to the measuring beam for interference. The interferometer arrangement includes a second measuring beam path and/or second reference beam path. The optical path lengths of the second measuring beam path and/or second reference beam path are different from one of the first beam paths. The wave length difference is selected according to a distance of two measuring areas which are arranged at a distance in the depth direction of the sample.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: July 19, 2011
    Assignee: Carl Zeiss Meditec AG
    Inventors: Adolf Friedrich Fercher, Rainer Leitgeb
  • Publication number: 20110149245
    Abstract: A device for performing distance measurements on an eye. The device includes an interferometer, focuses at least one measurement beam records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing the focus in the eye or for varying a polarization state of the measurement beam and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and actuates the adjustment apparatus for displacing the position of the focus or for varying the polarization while recording the backscattered radiation from which the control apparatus generates the A-scan individual signals is being recorded.
    Type: Application
    Filed: August 11, 2009
    Publication date: June 23, 2011
    Applicant: CARL ZEISS MEDITEC AG
    Inventors: Roland Barth, Roland Bergner, Wilfried Bissmann, Rudolf Murai von Buenau, Martin Hacker, Ingo Koschmieder, Adolf Friedrich Fercher, Branislav Grajciar, Ralf Ebersbach
  • Patent number: 7695137
    Abstract: Two problems arise when measuring length at the eye by short-coherence interferometry. First, the measurement focus and coherence window usually do not coincide. Second, the scanning process along the eye axis is time-consumin g. Both result in poor signal quality and inaccurate measurements. The present application is directed to a short-coherence interferometer in which a right-angle mirror and focusing optics jointly carry out a periodic back-and-forth movement in such a way that the measurement beam focus which is generated by the focusing optics and imaged on the eye by relay optics is moved synchronously with the coherence window from the cornea along the optic axis of the eye to the fovea centralis. Further, different path lengths are generated in the measurement beam path and reference beam path by means of a plurality of reflectors, so that the scanning process is limited to distances which are smaller than the optical length of the eye.
    Type: Grant
    Filed: February 4, 2005
    Date of Patent: April 13, 2010
    Assignee: Carl Zeiss Meditec AG
    Inventor: Adolf Friedrich Fercher
  • Patent number: 7695140
    Abstract: The present invention is directed to an ophthalmologic measurement method which can depict three-dimensional structures of the interfaces of an eye by short-coherence interferometry based on reference points. For this purpose, the pupil is illuminated at a plurality of points by a short-coherence illumination source. The measurement beam reflected at these points by the interfaces and surfaces of the eye is superimposed with a reference beam. The measurement data which are generated in this way are spectrally split by a diffraction grating, imaged on a two-dimensional detector array and conveyed to a control unit which determines a three-dimensional structure of all intraocular interfaces and surfaces of the eye. In the suggested Fourier domain OCT method, the depiction of three-dimensional structures is preferably carried out by spline surfaces or polygon surfaces.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: April 13, 2010
    Assignee: Carl Zeiss Meditec AG
    Inventor: Adolf Friedrich Fercher
  • Patent number: 7656537
    Abstract: The invention is directed to a device for determining the thickness, distance and/or profile of areas of a transparent and/or diffuse object that are spaced apart, in particular for measuring distances in the eye. In the device for determining position using an interferometer arrangement based on the Michelson principle, a scanning unit is arranged for the change in path length in the reference beam or measurement beam path. The scanning unit comprises a scan table which is movable translationally in corresponding guides, the movement direction enclosing an angle ? to the reference beam. At least two reference mirrors having a distance d in direction of the reference beam and slightly overlapping laterally are arranged on the scan table so that during the oscillating movement of the scan table carried out by a motor the reference beam is reflected in itself first by the first reference mirror and then by the second reference mirror.
    Type: Grant
    Filed: January 28, 2006
    Date of Patent: February 2, 2010
    Assignee: Carl Zeiss Meditec AG
    Inventor: Adolf Friedrich Fercher
  • Publication number: 20080285043
    Abstract: A device for the interferometric measurement of a sample, in particular the eye, including an interferometer arrangement with a first measurement beam path, through which a measurement beam falls onto the sample, and a first reference beam path, through which a reference beam runs, which is applied to the measuring beam for interference. The interferometer arrangement includes a second measuring beam path and/or second reference beam path. The optical path lengths of the second measuring beam path and/or second reference beam path are different from one of the first beam paths. The wave length difference is selected according to a distance of two measuring areas which are arranged at a distance in the depth direction of the sample.
    Type: Application
    Filed: December 6, 2006
    Publication date: November 20, 2008
    Applicant: CARL ZEISS MEDITEC AG
    Inventors: Adolf Friedrich Fercher, Rainer Leitgeb
  • Publication number: 20080284981
    Abstract: The present invention is directed to an ophthalmologic measurement method which can depict three-dimensional structures of the interfaces of an eye by short-coherence interferometry based on reference points. For this purpose, the pupil is illuminated at a plurality of points by a short-coherence illumination source. The measurement beam reflected at these points by the interfaces and surfaces of the eye is superimposed with a reference beam. The measurement data which are generated in this way are spectrally split by a diffraction grating, imaged on a two-dimensional detector array and conveyed to a control unit which determines a three-dimensional structure of all intraocular interfaces and surfaces of the eye. In the suggested Fourier domain OCT method, the depiction of three-dimensional structures is preferably carried out by spline surfaces or polygon surfaces.
    Type: Application
    Filed: July 26, 2005
    Publication date: November 20, 2008
    Inventor: Adolf Friedrich Fercher
  • Publication number: 20080218691
    Abstract: Two problems arise when measuring length at the eye by short-coherence interferometry. First, the measurement focus and coherence window usually do not coincide. Second, the scanning process along the eye axis is time-consuming. Both result in poor signal quality and inaccurate measurements. The present application is directed to a short-coherence interferometer in which a right-angle mirror and focusing optics jointly carry out a periodic back-and-forth movement in such a way that the measurement beam focus which is generated by the focusing optics and imaged on the eye by relay optics is moved synchronously with the coherence window from the cornea along the optic axis of the eye to the fovea centralis. Further, different path lengths are generated in the measurement beam path and reference beam path by means of a plurality of reflectors, so that the scanning process is limited to distances which are smaller than the optical length of the eye.
    Type: Application
    Filed: February 4, 2005
    Publication date: September 11, 2008
    Inventor: Adolf Friedrich Fercher
  • Patent number: 7113288
    Abstract: A method and/or arrangement for compensating the dispersion in signals of short-coherence interferometers and/or OCT interferometers, wherein the effect of the dispersion is eliminated by subsequent compensation in that the interferometer signal is correlated with a spatially variant correlation core which corresponds along the measurement axis in z-direction to an interferometer signal of an individual light-reemitting location with the same dispersion which is punctiform in z-direction.
    Type: Grant
    Filed: June 13, 2002
    Date of Patent: September 26, 2006
    Assignee: Carl Zeiss Jena GmbH
    Inventor: Adolf Friedrich Fercher
  • Patent number: 7079255
    Abstract: An airbag cover is defined by a predetermined breaking line which is introduced into a shaped flat material in a recessed manner. The recesses are achieved by removing material by means of laser radiation. According to the invention, the flat material is provided with a barrier layer. The barrier layer, by reason of its material properties, has greater resistance to removal of material by laser action than the material of the rest of the flat material. The recesses made by removing material extend along the predetermined breaking line in the flat material up to the barrier layer. The barrier layer makes it possible to produce a predetermined breaking line by means of laser machining which allows an exact residual wall thickness of the airbag cover in the area of the predetermined breaking line, so that the tearing strength can be adjusted very accurately, which is critically important for a reliable deployment of an airbag.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: July 18, 2006
    Assignee: Carl Zeiss Jena GmbH
    Inventor: Adolf Friedrich Fercher
  • Patent number: 6922250
    Abstract: The invention is directed to the detection and imaging of the internal geometry of the eye, particularly of the important components for imaging in the eye such as the cornea, lens, vitreous body and retinal surface, by multichannel short coherence interferometry. A method and arrangement for obtaining topograms and tomograms of the eye structure by many simultaneously recorded interferometric depth scans through transversely adjacent points in the pupil using spatially coherent or spatially partially coherent light sources. The depth scan is carried out by changing the optical length of the interferometer measurement arm by means of a retroreflector. By continuously displacing the retroreflector, the z-position of the light-reemitting point in the eye can be determined by means of the occurring interference. It is possible to record depth scans simultaneously through the use of spatially coherent or spatially partially coherent light beams comprising a plurality of partial beams.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: July 26, 2005
    Assignee: Carl Zeiss Meditec AG
    Inventor: Adolf Friedrich Fercher
  • Patent number: 6788421
    Abstract: Topographic measurement of eye structures based on short coherence interferometry is the subject of the invention. The problem occurring in this connection is that longitudinal and transverse eye movements during signal registration lead to errors in the measured structure. The influences of longitudinal eye movements are compensated in that the reference beam, independent from the measurement beam, is directed to the corneal vertex and is reflected at the latter. The influences of longitudinal eye movements are minimized in that the transverse position of the eye is monitored by means of a direction-dependent registration of the light reflected at the corneal vertex by means of a diode array or a four-quadrant diode and transverse misalignment is detected and compensated.
    Type: Grant
    Filed: June 10, 2002
    Date of Patent: September 7, 2004
    Assignee: Carl Zeiss Jena GmbH
    Inventors: Adolf Friedrich Fercher, Roland Barth
  • Publication number: 20030076506
    Abstract: An airbag cover is defined by a predetermined breaking line which is introduced into a shaped flat material in a recessed manner. The recesses are achieved by removing material by means of laser radiation. According to the invention, the flat material is provided with a barrier layer. The barrier layer, by reason of its material properties, has greater resistance to removal of material by laser action than the material of the rest of the flat material. The recesses made by removing material extend along the predetermined breaking line in the flat material up to the barrier layer. The barrier layer makes it possible to produce a predetermined breaking line by means of laser machining which allows an exact residual wall thickness of the airbag cover in the area of the predetermined breaking line, so that the tearing strength can be adjusted very accurately, which is critically important for a reliable deployment of an airbag.
    Type: Application
    Filed: October 10, 2002
    Publication date: April 24, 2003
    Inventor: Adolf Friedrich Fercher
  • Publication number: 20030072007
    Abstract: The invention is directed to the detection and imaging of the internal geometry of the eye, particularly of the important components for imaging in the eye such as the cornea, lens, vitreous body and retinal surface, by multichannel short coherence interferometry. A method and arrangement for obtaining topograms and tomograms of the eye structure by many simultaneously recorded interferometric depth scans through transversely adjacent points in the pupil using spatially coherent or spatially partially coherent light sources. The depth scan is carried out by changing the optical length of the interferometer measurement arm by means of a retroreflector. By continuously displacing the retroreflector, the z-position of the light-reemitting point in the eye can be determined by means of the occurring interference. It is possible to record depth scans simultaneously through the use of spatially coherent or spatially partially coherent light beams comprising a plurality of partial beams.
    Type: Application
    Filed: August 28, 2002
    Publication date: April 17, 2003
    Inventor: Adolf Friedrich Fercher
  • Publication number: 20030053072
    Abstract: Topographic measurement of eye structures based on short coherence interferometry is the subject of the invention. The problem occurring in this connection is that longitudinal and transverse eye movements during signal registration lead to errors in the measured structure. The influences of longitudinal eye movements are compensated in that the reference beam, independent from the measurement beam, is directed to the corneal vertex and is reflected at the latter. The influences of longitudinal eye movements are minimized in that the transverse position of the eye is monitored by means of a direction-dependent registration of the light reflected at the corneal vertex by means of a diode array or a four-quadrant diode and transverse misalignment is detected and compensated.
    Type: Application
    Filed: June 10, 2002
    Publication date: March 20, 2003
    Inventors: Adolf Friedrich Fercher, Roland Barth