Patent application number | Description | Published |
20140160495 | TWO-DIMENSIONAL, POSITION-SENSITIVE SENSOR-BASED SYSTEM FOR POSITIONING OBJECT HAVING SIX DEGREES OF FREEDOM IN SPACE - 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 | 06-12-2014 |
20150077032 | SINGLE DEGREE OF FREEDOM VIBRATION ISOLATING DEVICE OF LINEAR MOTOR AND MOTION CONTROL METHOD THEREOF - 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. | 03-19-2015 |
20150085302 | METHOD FOR MEASURING DISPLACEMENT OF LARGE-RANGE MOVING PLATFORM - 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. | 03-26-2015 |
20150097508 | METHOD FOR MEASURING DISPLACEMENT OF PLANAR MOTOR ROTOR - 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 B | 04-09-2015 |
20150268031 | DUAL-FREQUENCY GRATING INTERFEROMETER DISPLACEMENT MEASUREMENT SYSTEM - 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. The measurement system can realize sub-nanometer and even higher resolution and accuracy, and is able to measure long horizontal displacement and vertical displacement at the same time. | 09-24-2015 |
20150326150 | MAGLEV WORKPIECE TABLE WITH SIX DEGREES OF FREEDOM - A maglev working table with six degrees of freedom comprises a pedestal ( | 11-12-2015 |
20150338205 | HETERODYNE GRATING INTERFEROMETER DISPLACEMENT MEASUREMENT SYSTEM - 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. | 11-26-2015 |
20150362723 | OPTICAL GRATING PHASE MODULATOR FOR LASER INTERFERENCE PHOTOETCHING SYSTEM - 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. | 12-17-2015 |