Patents by Inventor Kinpui Chan

Kinpui Chan 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).

  • Publication number: 20150204651
    Abstract: Optical coherence tomography light sources can be non-linear and attempts to linearize them can lead to asynchrony between the light source and A-line scans and missampling in the scans causing signal noise. Accordingly, a system and methods are provided herein to detect missampling by obtaining a plurality of interferograms; providing at least two wavenumber reference signals at different wavenumbers, wherein the wavenumber reference signals comprise attenuated or enhanced portions of each of the plurality of interferograms; aligning each of the plurality of interferograms according to one of the at least two wavenumber reference signals; and for each of the plurality of interferograms, identifying an interferogram as missampled if another of the at least two reference signals does not align with a corresponding reference signal in a statistically significant number of the plurality of interferograms. An optical element, for example, an optical notch, may be used to generate the reference signals.
    Type: Application
    Filed: January 23, 2014
    Publication date: July 23, 2015
    Applicant: KABUSHIKI KAISHA TOPCON
    Inventors: Zhijia Yuan, Zhenguo Wang, Charles A. Reisman, Kinpui Chan
  • Patent number: 8970848
    Abstract: A motion detector 220 calculates the Doppler frequency shift amount based on the movement velocity of an eye E. A drive controller 230 calculates the modulation frequency of the intensity of output light M based on this Doppler frequency shift amount. A light source unit 201 outputs the light M in which the intensity is modulated with this modulation frequency. The light M is divided into a signal light S and a reference light R. Interference light L is generated by superimposing the signal light S passing through the eye E and the reference light R. Two polarized components of the interference light L have a phase difference of 180°, resulting from a quarter-wave plate 207. The polarized components L1, L2 which are divided by a polarization beam splitter 211 are detected by CCD 212, 213. A computer 250 forms a tomographical image based on these detection results.
    Type: Grant
    Filed: May 20, 2010
    Date of Patent: March 3, 2015
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Yasufumi Fukuma, Masahiro Akiba, Kinpui Chan
  • Patent number: 8939582
    Abstract: During scan capture with an OCT imaging system, the focal plane position can be simultaneously shifted over at least a portion of an image range. As a result, a plurality of image frames respectively corresponding to various focal plane positions is acquired. The image frames can be combined to generate a composite image having suitable resolution throughout the image range, including regions associated with weak-intensity or low-reflectance features. Further, windowed averaging can be performed prior to generation of the composite image so that the composite image incorporates weights given to image data in focus.
    Type: Grant
    Filed: July 12, 2013
    Date of Patent: January 27, 2015
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Richard F. Spaide, Charles A. Reisman, Zhenguo Wang, Kinpui Chan
  • Publication number: 20150015845
    Abstract: During scan capture with an OCT imaging system, the focal plane position can be simultaneously shifted over at least a portion of an image range. As a result, a plurality of image frames respectively corresponding to various focal plane positions is acquired. The image frames can be combined to generate a composite image having suitable resolution throughout the image range, including regions associated with weak-intensity or low-reflectance features. Further, windowed averaging can be performed prior to generation of the composite image so that the composite image incorporates weights given to image data in focus.
    Type: Application
    Filed: July 12, 2013
    Publication date: January 15, 2015
    Inventors: Richard F. Spaide, Charles A. Reisman, Zhenguo Wang, Kinpui Chan
  • Patent number: 8896841
    Abstract: An optical imaging method in an embodiment includes: a scanning step to scan each of a plurality of A-lines of an object with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences; a detection step to detect the interference light of the signal light passing through the A-line and the reference light; and an imaging step to generate a complex interference spectrum based on the detection results of the interference lights corresponding to the plurality of A-lines sequentially obtained in the detection step according to the scanning, and form, based on the complex interference spectrum, the tomographic image along the arrangement of the plurality of A-lines in which a complex conjugate artifact is substantially removed.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: November 25, 2014
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Zhijia Yuan, Zhenguo Wang, Kinpui Chan
  • Publication number: 20140204386
    Abstract: [Problem] Image artifacts caused by noises in clock signals are suppressed. [Solution] An image measuring method according to an embodiment comprises a clock generating step, a noise reducing step, a data acquisition step, a digital data generating step and an image data generating step. In the clock generating step, clock signals are generated. In the noise reducing step, the noise of the generated clock signals is reduced to a predetermined threshold or lower. In the data acquisition step, analog data indicating the inner morphology of an object is acquired. In the digital data generating step, digital data is generated by sampling the analog data based on the clock signals with reduced noise. In the image data generating step, image data of the object is generated by performing data processing including Fourier transform on the generated digital data.
    Type: Application
    Filed: September 19, 2013
    Publication date: July 24, 2014
    Applicant: KABUSHIKI KAISHA TOPCON
    Inventors: Zhenguo WANG, Zhijia YUAN, Kinpui CHAN
  • Publication number: 20140125988
    Abstract: An embodiment provides a method for setting the characteristics of the light to be output from a light source unit for optical coherence tomography, using a computer. This method is performed by using relation information in which a representative wavelength, a wavelength range including said representative wavelength, and the light loss amount due to absorption by a medium are related to each other. This method includes the following steps: setting each value of a first parameter and a second parameter among the representative wavelength, the wavelength range, and the light loss amount; acquiring a value of a third parameter among the representative wavelength, the wavelength range, and the light loss amount other than said first parameter and said second parameter based on the set two values and said relation information; and outputting a value of said acquired third parameter.
    Type: Application
    Filed: July 10, 2013
    Publication date: May 8, 2014
    Inventors: Zhenguo WANG, Zhijia YUAN, Kinpui CHAN
  • Patent number: 8564788
    Abstract: An optical imaging method is provided that can realize, at low cost, the extension of the imaging depth range. An optical imaging apparatus 400 is an apparatus that forms a tomographic image of an object using FD-OCT, and performs a scanning step, detection step and imaging step. In the scanning step, the object is scanned with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences. In the detection step, interference light of the signal light passing through the object and the reference light is detected. In the imaging step, a tomographic image of the object is formed based on the detection results of a plurality of the interference lights sequentially obtained in the detection step according to the scanning.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: October 22, 2013
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Zhijia Yuan, Zhenguo Wang, Kinpui Chan
  • Publication number: 20130242309
    Abstract: An optical imaging method in an embodiment includes: a scanning step to scan each of a plurality of A-lines of an object with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences; a detection step to detect the interference light of the signal light passing through the A-line and the reference light; and an imaging step to generate a complex interference spectrum based on the detection results of the interference lights corresponding to the plurality of A-lines sequentially obtained in the detection step according to the scanning, and form, based on the complex interference spectrum, the tomographic image along the arrangement of the plurality of A-lines in which a complex conjugate artifact is substantially removed.
    Type: Application
    Filed: March 13, 2012
    Publication date: September 19, 2013
    Applicant: KABUSHIKI KAISHA TOPCON
    Inventors: Zhijia YUAN, Zhenguo WANG, Kinpui CHAN
  • Patent number: 8488126
    Abstract: An optical image measurement device 1 causes an interference light generator to split a low-coherence light into a signal light and a reference light, and superimposes the signal light propagated through a measured object 5000 and the reference light propagated through the reference mirror 9 to generate an interference light. Two-dimensional photosensor arrays 14 and 15 detect the interference light. A computer 16 forms an image of the measured object 5000 based on the detection result. By inserting the optical fiber bundle 5 into the measured object 5000 to perform a measurement, a tomographic image of a deep tissue of the measured object 5000 can be obtained. Furthermore, the optical image measurement device 1 can form a high-resolution image of the deep tissue of the measured object 5000 because performing a measurement using the OCT technology.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: July 16, 2013
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Yasufumi Fukuma
  • Publication number: 20130027712
    Abstract: An optical imaging method is provided that can realize, at low cost, the extension of the imaging depth range. An optical imaging apparatus 400 is an apparatus that forms a tomographic image of an object using FD-OCT, and performs a scanning step, detection step and imaging step. In the scanning step, the object is scanned with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences. In the detection step, interference light of the signal light passing through the object and the reference light is detected. In the imaging step, a tomographic image of the object is formed based on the detection results of a plurality of the interference lights sequentially obtained in the detection step according to the scanning.
    Type: Application
    Filed: July 26, 2011
    Publication date: January 31, 2013
    Applicant: KABUSHIKI KAISHA TOPCON
    Inventors: Zhijia YUAN, Zhenguo WANG, Kinpui CHAN
  • Publication number: 20120113431
    Abstract: A motion detector 220 calculates the Doppler frequency shift amount based on the movement velocity of an eye E. A drive controller 230 calculates the modulation frequency of the intensity of output light M based on this Doppler frequency shift amount. A light source unit 201 outputs the light M in which the intensity is modulated with this modulation frequency. The light M is divided into a signal light S and a reference light R. Interference light L is generated by superimposing the signal light S passing through the eye E and the reference light R. Two polarized components of the interference light L have a phase difference of 180°, resulting from a quarter-wave plate 207. The polarized components L1, L2 which are divided by a polarization beam splitter 211 are detected by CCD 212, 213. A computer 250 forms a tomographical image based on these detection results.
    Type: Application
    Filed: May 20, 2010
    Publication date: May 10, 2012
    Applicant: KABUSHIKI KAISHA TOPCON
    Inventors: Yasufumi Fukuma, Masahiro Akiba, Kinpui Chan
  • Patent number: 8009297
    Abstract: Provided is an optical image measuring apparatus capable of obtaining a high-accuracy image without being influenced by a movement of an object to be measured. Flash light is emitted from a xenon lamp (2) and converted into broad band light by an optical filter (2A). A polarization characteristic of the flash light is converted into linear polarization by a polarizing plate (3). Then, the flash light is divided into signal light (S) and reference light (R) by a half mirror (6). A polarization characteristic of the reference light (R) is converted into circular polarization by a wavelength plate (7). The signal light (S) and the reference light (R) are superimposed on each other by the half mirror (6) to produce interference light (L). A CCD (23) detects interference light having the same characteristic as that of the produced interference light (L).
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: August 30, 2011
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba, Yasufumi Fukuma, Hisashi Tsukada
  • Patent number: 7952722
    Abstract: An optical image measurement device comprises: a light source configured to output a light having low temporal coherence and low spatial coherence; an optical system configured to split the light into a signal light and a reference light and superimpose the signal light having passed through a measured object and the reference light, thereby generating an interference light; a light receiver configured to receive the interference light and output an electric signal; and a forming part configured to form an image of the measured object based on the electric signal, wherein: the light receiver has a light receiving face on which a plurality of light receiving elements are arranged 2-dimensionally; and the optical system projects the interference light onto the light receiving face so that a size of the spatial coherent region of the interference light becomes equal to or larger than a size of the light receiving element.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: May 31, 2011
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba, Yasufumi Fukuma
  • Publication number: 20100134802
    Abstract: An optical image measurement device 1 causes an interference light generator to split a low-coherence light into a signal light and a reference light, and superimposes the signal light propagated through a measured object 5000 and the reference light propagated through the reference mirror 9 to generate an interference light. Two-dimensional photosensor arrays 14 and 15 detect the interference light. A computer 16 forms an image of the measured object 5000 based on the detection result. By inserting the optical fiber bundle 5 into the measured object 5000 to perform a measurement, a tomographic image of a deep tissue of the measured object 5000 can be obtained. Furthermore, the optical image measurement device 1 can form a high-resolution image of the deep tissue of the measured object 5000 because performing a measurement using the OCT technology.
    Type: Application
    Filed: August 1, 2008
    Publication date: June 3, 2010
    Applicant: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Yasufumi Fukuma
  • Publication number: 20090153873
    Abstract: Provided is an optical image measuring apparatus capable of obtaining a high-accuracy image without being influenced by a movement of an object to be measured. Flash light is emitted from a xenon lamp (2) and converted into broad band light by an optical filter (2A). A polarization characteristic of the flash light is converted into linear polarization by a polarizing plate (3). Then, the flash light is divided into signal light (S) and reference light (R) by a half mirror (6). A polarization characteristic of the reference light (R) is converted into circular polarization by a wavelength plate (7). The signal light (S) and the reference light (R) are superimposed on each other by the half mirror (6) to produce interference light (L). A CCD (23) detects interference light having the same characteristic as that of the produced interference light (L).
    Type: Application
    Filed: November 7, 2006
    Publication date: June 18, 2009
    Applicant: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba, Yasufumi Fukuma, Hisashi Tsukada
  • Publication number: 20090153876
    Abstract: An optical image measurement device comprises: a light source configured to output a light having low temporal coherence and low spatial coherence; an optical system configured to split the light into a signal light and a reference light and superimpose the signal light having passed through a measured object and the reference light, thereby generating an interference light; a light receiver configured to receive the interference light and output an electric signal; and a forming part configured to form an image of the measured object based on the electric signal, wherein: the light receiver has a light receiving face on which a plurality of light receiving elements are arranged 2-dimensionally; and the optical system projects the interference light onto the light receiving face so that a size of the spatial coherent region of the interference light becomes equal to or larger than a size of the light receiving element.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 18, 2009
    Applicant: Kabushi Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba, Yasufumi Fukuma
  • Patent number: 7548320
    Abstract: An optical image measuring apparatus including: a beam splitter (4) for dividing a light beam into signal light (S) and reference light (R); beam splitters for dividing the reference light (R) into plural reference light beams frequency shifters for shifting frequencies of the reference light beams by different amounts; and reflector plates arranged at different distances from an object to be measured (O). The reference light beams and the signal light (S) reflected by the object to be measured in depth regions are superimposed on each other to thereby produce interference light. CCD cameras receive the interference light component and convert the interference light component into electrical signals to output the signals. A computer forms images in depth regions corresponding to the interference light components based on the electrical signals.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: June 16, 2009
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba, Yasufumi Fukuma, Hiroyuki Otsuka, Hisashi Tsukada
  • Patent number: 7492466
    Abstract: Provided is an optical image measuring apparatus forming a three-dimensional image based on tomographic images of an object, acquired at various depths even when the object moves during measurement. Including a half mirror (6) for dividing a light beam signal light (S) and reference light (R), a frequency shifter (8), a reference mirror (9) and a piezoelectric element (9A) used to change an optical path length of the reference light (R), CCDs (21, 22) for receiving interference light beams (L) resulting from interference light produced by superimposing the signal light (S) and the reference light (R) on each other by the half mirror (6) and outputting detection signals, an image forming portion for forming tomographic images based on the detection signals, a measurement depth calculating means (53), and an image processing portion (57). Forming a three-dimensional image or the like based on the arranged tomographic images.
    Type: Grant
    Filed: October 11, 2005
    Date of Patent: February 17, 2009
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba, Yasufumi Fukuma, Hiroyuki Otsuka, Hisashi Tsukada, Kazuhiko Yumikake
  • Patent number: 7486402
    Abstract: An optical image measuring apparatus including a light emitting portion outputting light having different wavelengths intensity-modulating the light periodically, a polarizing plate converting a light to linearly polarized light, a half mirror dividing the light into signal light and reference light, a wavelength plate converting a polarization characteristic of the reference light, a frequency shifter shifting a frequency of the reference light, the half mirror superimposing the signal light and the reference light on each other to produce interference light, a polarization beam splitter extracting a polarized light from the interference light, CCDs detecting the extracted polarized interference light, and a signal processing portion forming an image of an object to be measured based on the polarized interference light related to each of the lights, detected by the CCDs.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: February 3, 2009
    Assignee: Kabushiki Kaisha Topcon
    Inventors: Kinpui Chan, Masahiro Akiba