Patents by Inventor Dengfeng Xu

Dengfeng Xu 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: 9310782
    Abstract: A method for measuring the displacement of a planar motor rotor. The measuring method comprises: four magnetic induction intensity sensors are distributed on the planar motor rotor; sampled signals of the four distributed sensors are processed to obtain signals Bsx, Bcx, Bsy and Bcy and magnetic field reference values Bksx, Bkcx, Bksy and Bkcy; and X-direction displacement and Y-direction displacement can be measured respectively according to inequalities (I) and (II) by judgments, wherein ?x and ?y are X-direction displacement resolution and Y-direction displacement resolution respectively, and BM is the magnetic induction intensity amplitude of the magnetic field of said planar motor. The method provided by the invention is simple in calculation, can avoid calculation of a transcendental function and solve the quadrant judgment problem, is favorable to real-time high-speed operation and has a high engineering value.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: April 12, 2016
    Assignees: SHANGHAI MICRO ELECTRONICS EQUIPMENT CO., LTD., TSINGHUA UNIVERSITY
    Inventors: Yu Zhu, Jinchun Hu, Dengfeng Xu, Yuting Sun, Wensheng Yin, Ming Zhang, Kaiming Yang, Haihua Mu
  • Publication number: 20150369331
    Abstract: A negative stiffness system for gravity compensation of a micropositioner of wafer table in lithography machine, characterized in that, the negative stiffness system includes at least three sets of quasi-zero stiffness units, each of the sets of quasi-zero stiffness units comprises a pair of negative stiffness springs and a positive stiffness spring, the positive stiffness spring is vertically positioned, the pair of negative stiffness springs are obliquely and symmetrically positioned at two sides of the positive stiffness spring, upper ends 20 of the negative stiffness springs and the positive stiffness spring are connected together and fixed to the bottom surface of a rotor of the micropositioner, and lower ends of the negative stiffness springs and the positive stiffness spring are connected to a base, respectively. The system reduces the stiffness in vertical direction and prevents the influence of permanent magnet on its surroundings, while improving the bearing capacity.
    Type: Application
    Filed: December 6, 2013
    Publication date: December 24, 2015
    Applicants: SHANGHAI MICRO ELECTRONICS EQUIPMENT CO., LTD., TSINGHUA UNIVERSITY
    Inventors: Yu ZHU, Ming ZHANG, Zhao LIU, Rong CHENG, Jing WANG, Li TIAN, Dengfeng XU, Kaiming YANG, Jinchun HU, Wensheng YIN, Haihua MU, Hao LIU, Chuxiong HU
  • Publication number: 20150362723
    Abstract: An optical grating phase modulator for a laser interference photoetching system is composed of a substrate, an optical grating, an electric motor and an optical grating positioner. The optical grating, the electric motor and the optical grating positioner are all mounted on the substrate. The optical grating is circular or rectangular, and adopt transmission or reflection type optical grating. A light beam is incident on the optical grating and generates diffraction, and when the electric motor drives the optical grating to continuously move relative to the incident light beam, diffracted light will generate a frequency shift, thereby realizing the phase modulation of the light beam. The optical grating phase modulator has the advantages of high phase modulation speed, high regulation precision and wide regulation range, thereby improving the whole performance of an interference photoetching system.
    Type: Application
    Filed: January 13, 2014
    Publication date: December 17, 2015
    Applicant: Tsinghua University
    Inventors: Yu Zhu, Ming Zhang, Leijie Wang, Rong Cheng, Kaiming Yang, Zhao Liu, Jinchun Hu, Wensheng Yin, Haihua MU, Chuxiong Hu, Dengfeng Xu
  • Publication number: 20150338205
    Abstract: A displacement measurement system of heterodyne grating interferometer, comprises a reading head, a measurement grating and an electronic signal processing component. Laser light emitted from the laser tube is collimated, passes through the first polarization spectroscope, and then emits two light beams with a vertical polarization direction and a vertical propagation direction; the two light beams pass through two acousto-optic modulators and respectively generate two first-order diffraction light beams with different frequencies, which are later divided into reference light and measurement light; two parallel reference light beams form a beat frequency electric signal with positive and negative first-order diffraction measurement light respectively after passing through a measurement signal photo-electric conversion unit; the beat frequency signals are transmitted to the electronic signal processing component for signal processing, thus the output of linear displacement in two directions is realized.
    Type: Application
    Filed: October 28, 2013
    Publication date: November 26, 2015
    Inventors: Ming ZHANG, Yu ZHU, Leijie WANG, Jinchun HU, Longmin CHEN, Kaiming YANG, Dengfeng XU, Wensheng YIN, Haihua MU
  • Publication number: 20150326150
    Abstract: A maglev working table with six degrees of freedom comprises a pedestal (800), a rotation drive apparatus, a planar-motion apparatus, an angle measuring apparatus (500), and a displacement measuring apparatus. The displacement measuring apparatus comprises four direct-current motors (600) and four displacement measuring apparatus PSD assemblies. Under the effect of the rotation drive apparatus, a planar-motion apparatus coil array stator (200) axially connected to a rotation drive apparatus circular permanent-magnet array mover (300) rotates, so that a phase difference is formed between a planar-motion apparatus permanent-magnet array mover (100) and the planar-motion apparatus coil array stator, and then the maglev working table mover, namely, the planar-motion apparatus permanent-magnet array mover rotates at 360° in the horizontal plane.
    Type: Application
    Filed: December 6, 2013
    Publication date: November 12, 2015
    Inventors: Yu ZHU, Ming ZHANG, Yujing SONG, Rong CHENG, Hao LIU, Zhao LIU, Kaiming YANG, Jinchun HU, Dengfeng XU, Wensheng YIN, Haihua MU
  • Patent number: 9182217
    Abstract: A method for measuring displacement of a large-range moving platform, comprising: arranging multiple beams of first measuring light parallel to one another and generated by an optical path distribution device and a position sensitive detector array in a certain manner, to ensure that at least one beam of first measuring light is detected by the position sensitive detector array when a moving platform is at any position of a moving area; a detection head array capable of determining whether a light beam is shaded being used for auxiliary measurement of a position of the moving platform; and determining a position of the moving platform that corresponds to the first measuring light measured by the position sensitive detector array, to calculate displacement of the moving platform. The method effectively enlarges a measurement range of the position sensitive detector array, and implements measurement of long range displacement of the moving platform.
    Type: Grant
    Filed: April 10, 2013
    Date of Patent: November 10, 2015
    Assignee: TSINGHUA UNIVERSITY
    Inventors: Ming Zhang, Yu Zhu, Hao Liu, Yi Jiang, Zhao Liu, Kaiming Yang, Jinchun Hu, Dengfeng Xu, Haihua Mu, Wensheng Yin
  • Publication number: 20150311099
    Abstract: A silicon wafer platform with anti-collision function comprises a silicon wafer platform body (1) and a cable platform (2). The cable platform (2) is mounted on one side of the silicon wafer platform. The silicon wafer platform comprises three airbags (3), four damping buffer elements (4) and an air source (6), the three airbags (3) being connected in series and respectively secured on the other three sides of the silicon wafer platform by an airbag support (5), two adjacent airbags (3) communicating with a gas pipeline by one damping buffer element (4), and the gas pipeline being secured on the cable platform (2) and communicating with the air source. When two silicon platforms collide, the collision is buffered by the airbags and the silicon wafer platforms are not bounced off.
    Type: Application
    Filed: December 6, 2013
    Publication date: October 29, 2015
    Inventors: Yu Zhu, Ming Zhang, Zhao Liu, Kaiming Yang, Dengfeng Xu, Li Tian, Li Zhang, Huichao Qin, Ping an Wang, Wensheng Yin, Jinchun Hu, Haihua Mu
  • Publication number: 20150268031
    Abstract: A dual-frequency grating interferometer displacement measurement system, comprises a dual-frequency laser, an interferometer, a measurement grating and an electronic signal processing component. The measurement system realizes displacement measurement based on grating diffraction, optical Doppler effect and optical beat frequency theory. Dual-frequency laser light is emitted from the dual-frequency laser and split into reference light and measurement light via a polarization spectroscope. The measurement light is incident to the measurement grating to generate positive and negative first-order diffraction. The diffraction light and the reference light form a beat frequency signal containing displacement information about two directions at a photo-detection unit, and linear displacement output is realized after signal processing.
    Type: Application
    Filed: October 28, 2013
    Publication date: September 24, 2015
    Inventors: Yu Zhu, Ming Zhang, Leijie Wang, Jinchun Hu, Longmin Chen, Kaiming Yang, Dengfeng Xu, Wensheng Yin, Haihua Mu
  • Patent number: 9030648
    Abstract: A dual wafer stage exchanging system for a lithographic device is disclosed, said system comprises two wafer stages running between an exposure workstation and a pre-processing workstation, and said two stages are set on a base and suspended above the upper surface of the base by air bearings. Each wafer stages is passed through by a Y-direction guide rail respectively, wherein one end of said guide rail is connected with a main driving unit and another end of said guide rail is detachably coupled with one of the two X-direction auxiliary driving units with single degree of freedom, and said two wafer stages are capable of moving in Y-direction along the guide rails and moving in X-direction under the drive of the auxiliary driving units with single degree of freedom. The position exchange of said two wafer stages can be enabled by the detachment and connection of the Y-direction guide rails and the auxiliary units with single degree of freedom.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: May 12, 2015
    Assignee: Tsinghua University
    Inventors: Yu Zhu, Ming Zhang, Jingsong Wang, Li Tian, Dengfeng Xu, Wensheng Yin, Guanghong Duan, Jinchun Hu
  • Publication number: 20150097508
    Abstract: A method for measuring the displacement of a planar motor rotor. The measuring method comprises: four magnetic induction intensity sensors are distributed on the planar motor rotor; sampled signals of the four distributed sensors are processed to obtain signals Bsx, Bcx, Bsy and Bcy and magnetic field reference values Bksx, Bkcx, Bksy and Bkcy; and X-direction displacement and Y-direction displacement can be measured respectively according to inequalities (I) and (II) by judgments, wherein ?x and ?y are X-direction displacement resolution and Y-direction displacement resolution respectively, and BM is the magnetic induction intensity amplitude of the magnetic field of said planar motor. The method provided by the invention is simple in calculation, can avoid calculation of a transcendental function and solve the quadrant judgment problem, is favorable to real-time high-speed operation and has a high engineering value.
    Type: Application
    Filed: February 21, 2013
    Publication date: April 9, 2015
    Inventors: Yu Zhu, Jinchun Hu, Dengfeng Xu, Yuting Sun, Wensheng Yin, Ming Zhang, Kaiming Yang, Haihua Mu
  • Publication number: 20150085302
    Abstract: A method for measuring displacement of a large-range moving platform, comprising: arranging multiple beams of first measuring light parallel to one another and generated by an optical path distribution device and a position sensitive detector array in a certain manner, to ensure that at least one beam of first measuring light is detected by the position sensitive detector array when a moving platform is at any position of a moving area; a detection head array capable of determining whether a light beam is shaded being used for auxiliary measurement of a position of the moving platform; and determining a position of the moving platform that corresponds to the first measuring light measured by the position sensitive detector array, to calculate displacement of the moving platform. The method effectively enlarges a measurement range of the position sensitive detector array, and implements measurement of long range displacement of the moving platform.
    Type: Application
    Filed: April 10, 2013
    Publication date: March 26, 2015
    Inventors: Ming Zhang, Yu Zhu, Hao Liu, Yi Jiang, Zhao Liu, Kaiming Yang, Jinchun Hu, Dengfeng Xu, Haihua Mu, Wensheng Yin
  • Publication number: 20150077032
    Abstract: A single degree of freedom vibration isolating device of a linear motor and a motion control method thereof. The vibration isolating device comprises a balance block, an anti-drifting driving unit, and a control unit. An upper surface of the balance block is connected to a stator of the linear motor, and a lower surface of the balance block is connected to a base. The anti-drifting driving unit is connected to the balance block for controlling the position of the balance block. Provided two motion control methods; inputting a second grating ruler signal to the control unit as feedback to perform variable stiffness and nonlinear control on the balance block; inputting a first and a second grating ruler signal to the control unit as feedback to obtain resultant centroid displacement signals of the rotor and the balance block to perform nonlinear anti-drifting control on the balance block.
    Type: Application
    Filed: April 15, 2013
    Publication date: March 19, 2015
    Applicant: TSINGHUA UNIVERSITY
    Inventors: Kaiming Yang, Yu Zhu, Dongdong Yu, Rong Cheng, Ming Zhang, Xin Li, Haihua Mu, Jinchun Hu, Dengfeng Xu, Wensheng Yin, Guofeng Ji
  • Patent number: 8958078
    Abstract: A two-dimensional, position-sensitive sensor-based system for positioning an object having six degrees of freedom in space, used for positioning of a silicon table and mask table of a lithography machine. The system comprises mainly a semiconductor laser 1, an optical fiber collimator 2, optical fibers 3, 7, 10, and 13, an optical fiber splitter 4, filter plates 6, 9, and 12, three PSD sensors 5, 8, and 11, and a signal processing system. Laser emitted by the semiconductor laser 1 is irradiated onto the optical fiber collimator 2, then transmitted respectively via three paths, and received by the PSD sensors 5, 8, and 11 after having background light filtered out by the filter plates 6, 9, and 12, while the positions of laser spots on the three PSD sensors 5, 8, and 11 are processed by the signal processing system to acquire the position and orientation.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: February 17, 2015
    Assignee: Tsinghua University
    Inventors: Ming Zhang, Yu Zhu, Zhao Liu, Jinchun Hu, Dengfeng Xu, Kaiming Yang, Wensheng Yin, Haihua Mu
  • Publication number: 20150012242
    Abstract: A planar motor rotor displacement measuring device and its measuring method are provided. The motor is a moving-coil type planar motor. The device comprises probes, two sets of sine sensors, two sets of cosine sensors, a signal lead wire and a signal processing circuit. The method is arranging two sets of magnetic flux density sensors within a magnetic field pitch ? along two vertical movement directions in the rotor located in the sine magnetic field area. Sampled signals of the four sets of sensors are respectively processed with a frequency multiplication operation, four subdivision signals are obtained, the zero-crossing points of the four subdivision signals are detected, and then two sets of orthogonal pulse signals are generated. The pulse number of the orthogonal pulse signals is counted, and phase difference of the two sets of orthogonal pulse signals is respectively detected.
    Type: Application
    Filed: February 8, 2013
    Publication date: January 8, 2015
    Inventors: Jinchun Hu, Yu Zhu, Wensheng Yin, Longmin Chen, Kaiming Yang, Ming Zhang, Dengfeng Xu, Haihua Mu, Chuxiong Hu, Zhao Liu
  • Patent number: 8860927
    Abstract: A dual-stage exchange system for a lithographic apparatus comprises a silicon chip stage (13) operating in an exposure workstation (3) and a silicon chip (14) stage operating in a pre-processing workstation (4). The two silicon chip stages (13, 14) are provided on the same base stage (1), and suspended on an upper surface (2) of the base stage by air bearings. The two silicon chip stages (13, 14) can move along guide rails (15, 16) in the Y direction. One end of each guide rail (15, 16) is connected to a main driving unit (11, 12), and the other end of each guide rail (15, 16) is butt-jointed with an X-direction single-freedom auxiliary driving unit (7, 8). The silicon chip stages (13, 14) are driven by the single-freedom auxiliary driving units (7, 8) cooperated with the main driving units (11, 12) to move along the X direction.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: October 14, 2014
    Assignee: Tsinghua University
    Inventors: Yu Zhu, Ming Zhang, Jingsong Wang, Li Tian, Dengfeng Xu, Wensheng Yin, Guanghong Duan, Jinchun Hu
  • Patent number: 8836918
    Abstract: A dual-stage exchange system for a lithographic apparatus comprises a silicon chip stage (10) operating in an exposure workstation (6) and a silicon chip stage (12) operating in a pre-processing workstation (7). Each silicon chip stage (10, 12) is supported by a six-freedom micro-motion stage, respectively. The silicon chip stage (10, 12) and the six-freedom micro-motion stage form a silicon chip stage group. The two silicon chip stage groups are provided on the same rectangular base stage (1) and suspended on an upper surface (2) of the base sage by air bearings. A double-freedom driving unit (21a, 21b, 22a, 22b) is provided on each edge of the base stage (1), respectively. The six-freedom micro-motion stage of the silicon chip stage group has an upper layer driver and a lower layer driver, capable of achieving six-freedom control.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: September 16, 2014
    Assignee: Tsinghua University
    Inventors: Yu Zhu, Ming Zhang, Jingsong Wang, Li Tian, Dengfeng Xu, Wensheng Yin, Guanghong Duan, Jinchun Hu
  • Publication number: 20140160495
    Abstract: A two-dimensional, position-sensitive sensor-based system for positioning an object having six degrees of freedom in space, used for positioning of a silicon table and mask table of a lithography machine. The system comprises mainly a semiconductor laser 1, an optical fiber collimator 2, optical fibers 3, 7, 10, and 13, an optical fiber splitter 4, filter plates 6, 9, and 12, three PSD sensors 5, 8, and 11, and a signal processing system. Laser emitted by the semiconductor laser 1 is irradiated onto the optical fiber collimator 2, then transmitted respectively via three paths, and received by the PSD sensors 5, 8, and 11 after having background light filtered out by the filter plates 6, 9, and 12, while the positions of laser spots on the three PSD sensors 5, 8, and 11 are processed by the signal processing system to acquire the position and orientation.
    Type: Application
    Filed: July 26, 2012
    Publication date: June 12, 2014
    Applicant: TSINGHUA UNIVERSITY
    Inventors: Ming Zhang, Yu Zhu, Zhao Liu, Jinchun Hu, Dengfeng Xu, Kaiming Yang, Wensheng Yin, Haihua Mu
  • Publication number: 20140127804
    Abstract: Methods for treating a bioprosthetic tissue are described herein. The methods comprise contacting the bioprosthetic tissue with at least one nucleophile and/or at least one electrophile in the presence of a catalytic system comprising at least one or a combination of a fluoride-based salt, a cesium-based salt, a potassium-based salt, a rubidium-based salt, or a carbonate-based salt. The methods may be used to alter functional groups on biological tissue which represent actual and potential calcium binding sites and also processes for cross-linking bioprosthetic tissue. Both processes may be used in conjunction with known fixative techniques, such as glutaraldehyde fixation, or may be used to replace known fixative techniques.
    Type: Application
    Filed: November 7, 2013
    Publication date: May 8, 2014
    Applicant: EDWARDS LIFESCIENCES CORPORATION
    Inventors: Dengfeng Xu, Jeffrey S. Dove
  • Publication number: 20140071422
    Abstract: Disclosed is a dual wafer stage switching system for a lithography machine. The system comprises a base stage (30), a wafer stage (16.1) running at a pre-processing workstation, and a wafer stage (16.2) running at an exposure workstation. A rotating motor (41) is mounted under the base stage (30) for rotating the two wafer stages after the wafer stages have completed pre-processing and exposure operations in order to complete position switch of the wafer stages, wherein the base stage (30) is kept stationary during the switch. The present invention avoids rotation of a large inertia base stage and has low requirement for motor power, while eliminating a guide rail docking device and an auxiliary device and greatly simplifying system configuration. The system is easy and convenient to operate and easy to control.
    Type: Application
    Filed: March 23, 2012
    Publication date: March 13, 2014
    Applicant: TSINGHUA UNIVERSITY
    Inventors: Yu Zhu, Yaying Chen, Ming Zhang, Dengfeng Xu, Jinsong Wang
  • Publication number: 20130024157
    Abstract: A two-dimensional locating method of a motion platform based on a magnetic steel array involves the following steps: placing more than four linear Hall sensors at any different positions within one or more polar distances of the magnetic steel array on the surface of the motion platform in a motion system; determining a magnetic flux density distribution model according to the magnetic steel array; determining the mounting positions of the above-mentioned linear Hall sensors, which are converted into phases with respect to the mass center of the motion platform; recording the magnetic flux density measured values of the linear Hall sensors as the motion proceeds; solving the phases of the mass center of the motion platform in a plane, with the measured values being served as observed quantities and the magnetic flux density distribution model being served as a computation model; and determining the position of the mass center of the motion platform with respect to an initial phase according to the phase, so a
    Type: Application
    Filed: January 18, 2011
    Publication date: January 24, 2013
    Inventors: Jinchun Hu, Yu Zhu, Jinsong Wang, Ming Zhang, Kai Liao, Kaiming Yang, Dengfeng Xu, Wensheng Yin, Guanghong Duan