Patents by Inventor Heui Jae Pahk
Heui Jae Pahk 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: 12216044Abstract: System for measuring the thickness and properties of a thin film using a spatial light modulator according to the inventive concept includes: a spatial light modulator; a first beam splitter; an objective lens; a second beam splitter; a first camera configured to acquire a surface image of the sample; an optical fiber equipped with a light receiving unit to receive reflected light passing through a certain area of a back focal plane of the objective lens; and a spectrometer configured to measure an intensity of light received from the optical fiber and output the measured intensity as an electrical signal.Type: GrantFiled: March 29, 2021Date of Patent: February 4, 2025Assignee: SEOUL NATIONAL UNIVERSITY R&DB FOUNDATIONInventors: Heui Jae Pahk, Seung Woo Lee, Min Gyu Kim
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Publication number: 20240369473Abstract: Provided are an angle-resolved spectroscopic ellipsometer and a method of measuring thickness of a thin film. The ellipsometer includes: a spatial light modulator spatially modulating light to a back focal plane of an objective lens; an incident light controller controlling the light emitted from the spatial light modulator to form a ring-shaped image and controlling the amount of light to have a sinusoidal distribution along the circumference of a ring; a polarizer polarizing the light from the modulator; a first beam splitter changing the direction of the light; the objective lens allowing the light to incident on the sample; an analyzer analyzing the polarization of the light from the sample; a camera capturing an image; a spectrometer receiving a signal of light; a second beam splitter; and a signal processing computer calculating a physical property value of a thin film by processing the signal.Type: ApplicationFiled: April 23, 2024Publication date: November 7, 2024Inventors: Heui Jae PAHK, Min Gyu KIM
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Publication number: 20230266233Abstract: System for measuring the thickness and properties of a thin film using a spatial light modulator according to the inventive concept includes: a spatial light modulator; a first beam splitter; an objective lens; a second beam splitter; a first camera configured to acquire a surface image of the sample; an optical fiber equipped with a light receiving unit to receive reflected light passing through a certain area of a back focal plane of the objective lens; and a spectrometer configured to measure an intensity of light received from the optical fiber and output the measured intensity as an electrical signal.Type: ApplicationFiled: March 29, 2021Publication date: August 24, 2023Inventors: Heui Jae PAHK, Seung Woo LEE, Min Gyu KIM
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Patent number: 9696144Abstract: Provided herein is a three-dimensional shape measurement apparatus capable of measuring a shape of a measurement object using an interferometer and color information of the measurement object, the apparatus including a light source for emitting a light; a light divider for reflecting the light emitted from the light source or transmitting a light reflected by the measurement object; a lens unit for focusing the light reflected by the light divider onto the measurement object; a light detector for detecting the light reflected from the measurement object; and a light adjuster arranged on a light path between the light source and the light divider, and configured to interrupt the light being emitted from a central area of the light source to reduce interference of light occurring in the lens unit.Type: GrantFiled: March 17, 2014Date of Patent: July 4, 2017Assignee: SNU PRECISION CO., LTD.Inventors: Tae Yong Jo, Young Min Hwang, Seong Ryong Kim, Sang Soo Kang, Heui Jae Pahk
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Publication number: 20160102970Abstract: Provided herein is a three-dimensional shape measurement apparatus capable of measuring a shape of a measurement object using an interferometer and color information of the measurement object, the apparatus including a light source for emitting a light; a light divider for reflecting the light emitted from the light source or transmitting a light reflected by the measurement object; a lens unit for focusing the light reflected by the light divider Onto the measurement object; a light detector for detecting the light reflected from the measurement object; and a light adjuster arranged on a light path between the light source and the light divider, and configured to interrupt the light being emitted from a central area of the light source to reduce interference of light occurring in the lens unit.Type: ApplicationFiled: March 17, 2014Publication date: April 14, 2016Inventors: Tae Yong Jo, Young Min Hwang, Seong Ryong Kim, Sang Soo Kang, Heui Jae Pahk
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Patent number: 8947673Abstract: Disclosed is a method of measuring thickness or a surface profile of a thin film layer formed on a base layer through a white light scanning interferometry, the method including: preparing simulation interference signals corresponding to thicknesses by assuming a plurality of sample thin film layers different in thickness from one another and simulating interference signals with respect to the respective sample thin film layers; acquiring a real interference signal with respect to an optical-axis direction of entering the thin film layer by illuminating the thin film layer with white light; preparing a plurality of estimated thicknesses that the thin film layer may have on the basis of the real interference signal; comparing whether the simulation interference signal having thickness corresponding to the estimated thickness is substantially matched with the real interference signal; and determining the thickness of the simulation interference signal substantially matched with the real interference signal as tType: GrantFiled: January 16, 2009Date of Patent: February 3, 2015Assignee: Snu Precision Co., Ltd.Inventors: Heui Jae Pahk, Woo Jung Ahn, Seong Ryong Kim, Jun Hyeok Lee
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Patent number: 8873067Abstract: Provided herein is a TSV measuring interferometer that uses a variable field stop that adjusts such that a light is focused at an inlet and at a bottom surface of a TSV when measuring a diameter and depth of the TSV, thereby reducing a measurement time and result data, the interferometer also using a telecentric lens that adjusts the light injected into the TSV to be a straight line, so as to obtain a sufficient amount of light reaching the bottom surface to improve the accuracy of measurement even in a TSV having a large aspect ratio.Type: GrantFiled: April 13, 2012Date of Patent: October 28, 2014Assignee: Snu Precision Co., Ltd.Inventors: Ki Hun Lee, Heung Hyun Shin, Heui Jae Pahk
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Publication number: 20140036273Abstract: Provided herein is a TSV measuring interferometer that uses a variable field stop that adjusts such that a light is focused at an inlet and at a bottom surface of a TSV when measuring a diameter and depth of the TSV, thereby reducing a measurement time and result data, the interferometer also using a telecentric lens that adjusts the light injected into the TSV to be a straight line, so as to obtain a sufficient amount of light reaching the bottom surface to improve the accuracy of measurement even in a TSV having a large aspect ratio.Type: ApplicationFiled: April 13, 2012Publication date: February 6, 2014Applicant: SNU PRECISION CO LTDInventors: Ki Hun Lee, Heung Hyun Shin, Heui Jae Pahk
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Patent number: 8279447Abstract: Disclosed is a method for measuring a thickness of a subjecting layer attached on a base layer by means of an interferometer, which includes the steps of: obtaining a correlation equation of a phase difference with respect to thicknesses of sample layers, the thicknesses being different from each other, the sample layers being made from a material substantially equal to a material of the subjecting layer; obtaining a first interference signal with respect to an optical axial direction incident to the base layer at a boundary surface between an air layer and the base layer; obtaining a second interference signal with respect to the optical axial direction at a boundary surface between the subjecting layer and the base layer; obtaining a phase difference between a phase of the first interference signal and a phase of the second interference signal at respective heights substantially equal to each other with respect to the optical axial direction; and determining a thickness of the subjecting layer by insertingType: GrantFiled: April 1, 2008Date of Patent: October 2, 2012Assignee: Snu Precision Co., Ltd.Inventors: Heui-Jae Pahk, Young-Min Hwang, Woo-Jung Ahn
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Patent number: 8199332Abstract: A thickness measurement apparatus includes a beam splitter for reflecting or transmitting a ray irradiated from an optical source or a ray reflected by a measurement object; a first lens part which condenses a ray to the measurement object and generates a reference ray; a second lens part for condensing a ray to the object to be measured; an interference light detector for detecting an interference signal generated by the reflected ray and reference ray; a spectroscopic detector corresponding to the second lens part to form a light path different from the path formed by the interference light detector and splits the ray reflected by the measurement object to detect an intensity and wavelength of each split ray; and a light path converter for selectively transmitting a ray to the interference light detector or spectroscopic detector, wherein position exchanging is performed between the first second lens parts.Type: GrantFiled: April 2, 2008Date of Patent: June 12, 2012Assignee: Snu Precision Co., Ltd.Inventors: Heui-Jae Pahk, Woo-Jung Ahn, Young-Min Hwang, Chang-Yeol Lee, Ji-Won Choi
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Publication number: 20110188048Abstract: Disclosed is a method of measuring thickness or a surface profile of a thin film layer formed on a base layer through a white light scanning interferometry, the method including: preparing simulation interference signals corresponding to thicknesses by assuming a plurality of sample thin film layers different in thickness from one another and simulating interference signals with respect to the respective sample thin film layers; acquiring a real interference signal with respect to an optical-axis direction of entering the thin film layer by illuminating the thin film layer with white light; preparing a plurality of estimated thicknesses that the thin film layer may have on the basis of the real interference signal; comparing whether the simulation interference signal having thickness corresponding to the estimated thickness is substantially matched with the real interference signal; and determining the thickness of the simulation interference signal substantially matched with the real interference signal as tType: ApplicationFiled: January 16, 2009Publication date: August 4, 2011Applicant: SNU PRECISION CO., LTD.Inventors: Heui Jae Pahk, Woo Jung Ahn, Seong Ryong Kim, Jun Hyeok Lee
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Publication number: 20110001988Abstract: An apparatus for measuring a thickness, which includes: a first beam splitter for reflecting or transmitting a ray irradiated from an optical source or a ray reflected by a measurement object; a first lens part which condenses a ray to the measurement object and generates a reference ray having a difference of a light path in comparison with a ray reflected by the measurement object; a second lens part for condensing a ray to the object to be measured; an interference light detector which corresponds to at the first lens part so as to form a light path and detects an interference signal generated by the ray reflected by the measurement object and the reference ray; a spectroscopic detector which corresponds to the second lens part so as to form a light path different from the light path formed by the interference light detector and splits the ray reflected by the measurement object so as to detect an intensity and a wavelength of each split ray; and a light path converter for selectively transmitting a ray toType: ApplicationFiled: April 2, 2008Publication date: January 6, 2011Applicant: SNU PRECISION CO., LTD.Inventors: Heui-Jae Pahk, Woo-Jung Ahn, Young-Min Hwang, Chang-Yeol Lee, Ji-Won Choi
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Publication number: 20100277745Abstract: Disclosed is a method for measuring a thickness of a subjecting layer attacked on a base layer by means of an interferometer, which includes the steps of: obtaining a correlation equation of a phase difference with respect to thicknesses of sample layers, the thicknesses being different from each other, the sample layers being made from a material substantially equal to a material of the subjecting layer; obtaining a first interference signal with respect to an optical axial direction incident to the base layer at a boundary surface between an air layer and the base layer; obtaining a second interference signal with respect to the optical axial direction at a boundary surface between the subjecting layer and the base layer; obtaining a phase difference between a phase of the first interference signal and a phase of the second interference signal at respective heights substantially equal to each other with respect to the optical axial direction; and determining a thickness of the subjecting layer by insertingType: ApplicationFiled: April 1, 2008Publication date: November 4, 2010Applicant: SNU PRECISION CO., LTD.Inventors: Heui-Jae Pahk, Young-Min Hwang, Woo-Jung Ahn
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Publication number: 20100006549Abstract: Disclosed is a laser processing device for processing a surface of an object with laser beams. The laser processing device includes: a laser beam generating unit for projecting laser beams; and a micromirror device having a plurality of micromirrors, the micromirrors being configured to reflect and transfer at least a part of laser beams projected from the laser beam generating unit to the surface of the object in a pattern for processing the surface of the object in a desired shape. The micromirrors of the micromirror device are capable of selectively switching the light path of the laser beams projected from the laser beam generating unit. According to the present invention, a surface of an object can be either two-dimensionally or three-dimensionally processed in a desired shape with laser beams.Type: ApplicationFiled: June 15, 2007Publication date: January 14, 2010Applicant: SNU PRECISION CO., LTD.Inventors: Heui Jae Pahk, Tai Wook Kim, Heung Hyun Shin
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Patent number: 7308130Abstract: Provided is a machine and a method for inspecting an input shaft of a power system. First an second cameras take a photograph of first and second champer of the input shaft from directions perpendicular to the chamfers to capture image data of the chamfers. The input shaft is rotated by an indexing drive until overlapping a central line of first and second chamfers of an input shaft on a standard line of image array coordinate system of a computer. Then, widths of the first and second chamfers of the input shaft is calculated. Thereafter, the indexing drive rotates the input shaft by predetermined degrees. The computer processes image data of another first and second chamfers captured by the first and second cameras and calculates widths of the another first and second chamfers. Continuously, widths of remaining chamfers of the input shaft are calculated.Type: GrantFiled: November 30, 2002Date of Patent: December 11, 2007Assignee: SNU Precision Co., Ltd.Inventors: Heui-Jae Pahk, Moon-Tae Hwang, Jin-Ki Kim
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Patent number: 7243571Abstract: Provided is an ultra-precision positioning system. The system comprises a base, a motion stage movably provided to the top of the base, and first to sixth feeding mechanisms for moving the motion stage to have six degrees of freedom. The first to sixth feed mechanisms are fixed to the base and the motion stage, respectively. Each of the first to third feeding mechanisms has a piezo actuator and two elastic hinges provided at both sides of the piezo actuator. Each of the fourth to sixth feeding mechanisms has a piezo actuator, three hinge members, and a lever member with a notch hinge which operatively cooperates with the hinge members.Type: GrantFiled: August 6, 2001Date of Patent: July 17, 2007Inventors: Heui-Jae Pahk, Jong-Ho Park
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Patent number: 7113273Abstract: Provided is a machine for inspecting ferrules of an optical connector and a method thereof. A fixture arranges the ferrules on a rectangular system to inspect the ferrules. A robot centers first ferrule on a optical system and focuses the first ferrule on the optical system. The optical system includes two cameras for photographing inside diameter image data and outside diameter image data of the ferrule. While the robot moves sequentially the optical system and remaining ferrules, all the inside and outside diameter image data of the ferrules are in sequence obtained by the optical system. Each inside and outside diameter and eccentricity of the ferrules are calculated by the obtained inside and outside diameter image data via a computer program.Type: GrantFiled: January 17, 2003Date of Patent: September 26, 2006Inventors: Heui-Jae Pahk, Il-Hwan Lee, Hwa-Kyun Lee, Dong-Sung Lee
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Patent number: 6860020Abstract: Provided is an ultra-precision feeding apparatus. The feeding apparatus comprises an actuator horizontally positioned between a base and a motion stage movably provided to the top of the base, first hinge member which is fixed to the base and one end of the actuator, second hinge member which is fixed to the other end of the actuator, third hinge member with two hinges which is fixed to the motion stage, and a lever member with a notch hinge which is fixed to the base and cooperates with the second hinge member and the third hinge member.Type: GrantFiled: August 6, 2001Date of Patent: March 1, 2005Inventors: Heui-Jae Pahk, Jong-Ho Park
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Publication number: 20050041241Abstract: Provided is a machine for inspecting ferrules of an optical connector and a method thereof. A fixture arranges the ferrules on a rectangular system to inspect the ferrules. A robot centers first ferrule on a optical system and focuses the first ferrule on the optical system. The optical system includes two cameras for photographing inside diameter image data and outside diameter image data of the ferrule. While the robot moves sequentially the optical system and remaining ferrules, all the inside and outside diameter image data of the ferrules are in sequence obtained by the optical system. Each inside and outside diameter and eccentricity of the ferrules are calculated by the obtained inside and outside diameter image data via a computer program.Type: ApplicationFiled: January 17, 2003Publication date: February 24, 2005Inventors: Heui-Jae Pahk, Il-Hwan Lee, Hwa-Kyun Lee, Dong-Sung Lee
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Publication number: 20050000051Abstract: Provided is a machine and a method for inspecting an input shaft of a power system. First an second cameras take a photograph of first and second champer of the input shaft from directions perpendicular to the chamfers to capture image data of the chamfers. The input shaft is rotated by an indexing drive until overlapping a central line of first and second chamfers of an input shaft on a standard line of image array coordinate system of a computer. Then, widths of the first and second chamfers of the input shaft is calculated. Thereafter, the indexing drive rotates the input shaft by predetermined degrees. The computer processes image data of another first and second chamfers captured by the first and second cameras and calculates widths of the another first and second chamfers. Continuously, widths of remaining chamfers of the input shaft are calculated.Type: ApplicationFiled: November 30, 2002Publication date: January 6, 2005Inventors: Heui-Jae Pahk, Moon-Tae Hwang, Jin-Ki Kim