Patents by Inventor Yaichi Okubo
Yaichi Okubo 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: 8872064Abstract: A positioning control system for positioning a moving element on a basis of position command data is provided with a feedback loop. The system is also provided with a loop gain modifier for determining a loop gain, which is to be used in a following positioning operation, on a basis of a difference between an amount of overshoot measured in a current positioning operation and a predetermined tolerance or on a basis of a difference between an amount of overshoot measured in a current positioning operation and a first predetermined tolerance and a difference between an amount of undershoot measured in the current positioning operation and a second predetermined tolerance. The first and second tolerances may preferably be the same in absolute value. The moving element may specifically be a steerable mirror for drilling holes in a work by reflecting a laser beam. Also disclosed is a laser drilling machine including the system.Type: GrantFiled: February 16, 2007Date of Patent: October 28, 2014Assignees: Via Mechanics, Ltd., National University Corporation Nagoya Institute of TechnologyInventors: Takashi Ono, Souichi Toyama, Yaichi Okubo, Hiromu Hirai
-
Patent number: 7768225Abstract: A difference between each position command data outputted in a form of a step signal from a high-level controller and its corresponding detected position data of a movable body is integrated by an integral compensator to position the movable body. Assuming, for example, that the movable body is a steerable mirror, digital filters are arranged to compensate the value of an initial state of an angular displacement and the value of an initial state of an angular velocity, respectively, and respective impulse responses of the digital filters as additional input elements are added to an output terminal of the integral compensator. For higher effectiveness, internal state variables of the digital filters can desirably be cleared to zero whenever an angle (position) command data is received.Type: GrantFiled: February 4, 2005Date of Patent: August 3, 2010Assignee: Hitachi Via Mechanics Ltd.Inventors: Souichi Toyama, Yaichi Okubo, Hiromu Hirai, Makoto Iwasaki, Motohiro Kawafuku, Noriaki Hirose
-
Patent number: 7612479Abstract: A scanner has a rotor, and a stator disposed in the outside of the rotor. The rotor includes a shaft, and a permanent magnet mounted on the outer circumferential side of the shaft. The stator includes a casing, a yoke held in the inner circumferential side of the casing, and coils disposed in the inner circumferential side of the yoke. The permanent magnet of the rotor has radially depressed grooves formed in its outer circumferential portion. The torque constant of the scanner is circumferentially equalized by the grooves.Type: GrantFiled: June 23, 2006Date of Patent: November 3, 2009Assignee: Hitachi Via Mechanics, Ltd.Inventors: Akira Doi, Haruaki Otsuki, Atsushi Sakamoto, Souichi Toyama, Yaichi Okubo
-
Patent number: 7496415Abstract: A digital servo control unit which uses a D/A converter, which suppresses the spike-like pulsation superimposed on a current error signal inside a current control circuit, and which has control performance not lower than that in the background art even when a low-voltage and low-price power supply circuit is used. A first-order low pass filter acts on an analog signal output by the D/A converter, and a stabilizing compensation occurs for a phase delay caused by the first-order low pass filter. The first-order low pass filter is formed as a low pass filter having a cut-off frequency which is lower than a sampling frequency. The first-order low pass filter may be replaced by a notch filter having a cut-off frequency which is equal to a sampling frequency or which is equal to an integer multiple of a Nyquist frequency.Type: GrantFiled: May 30, 2006Date of Patent: February 24, 2009Assignee: Hitachi Via Mechanics, Ltd.Inventors: Souichi Toyama, Yaichi Okubo
-
Patent number: 7432681Abstract: A scanner system includes a servo control unit. A rotation angle of a rotating shaft supporting a mirror is detected, and an error of the detected value with respect to a commanded value is integrated by an integral compensator so that the detected value is able to track the commanded value. A tracking error proportional compensator is disposed in parallel with the integral compensator so as to add a correction value proportional to the error to the integrated value of the error. A plurality of gains are prepared for each of the integral compensator, the tracking error proportional compensator, a detected value proportional compensator and a detected value differential compensator of the servo control unit. Each gain is changed in accordance with a travel angle of the commanded value. Thus, the mirror can be positioned quickly so that the machining speed can be improved.Type: GrantFiled: August 27, 2004Date of Patent: October 7, 2008Assignee: Hitachi Via Mechanics, Ltd.Inventors: Souichi Toyama, Haruaki Otsuki, Atsushi Sakamoto, Kenta Seki, Yaichi Okubo
-
Publication number: 20070227773Abstract: A positioning control system for positioning a moving element on a basis of position command data is provided with a feedback loop. The system is also provided with a loop gain modifier for determining a loop gain, which is to be used in a following positioning operation, on a basis of a difference between an amount of overshoot measured in a current positioning operation and a predetermined tolerance or on a basis of a difference between an amount of overshoot measured in a current positioning operation and a first predetermined tolerance and a difference between an amount of undershoot measured in the current positioning operation and a second predetermined tolerance. The first and second tolerances may preferably be the same in absolute value. The moving element may specifically be a steerable mirror for drilling holes in a work by reflecting a laser beam. Also disclosed is a laser drilling machine including the system.Type: ApplicationFiled: February 16, 2007Publication date: October 4, 2007Applicants: Hitachi Via Mechanics, Ltd., National University CorporationInventors: Takashi Ono, Souichi Toyama, Yaichi Okubo, Hiromu Hirai
-
Patent number: 7270270Abstract: A optical scanner control method and a optical scanner capable of positioning a mirror at a high speed independently of a rocking angle, and a laser machining apparatus for irradiating a printed circuit board with a laser beam by use of the optical scanner to thereby perforate the printed circuit board. In order to operate an actuator for rocking the mirror based on a deviation of a current position from an commanded value, a change in gain of the actuator is measured in accordance with each rocking angle in advance, and the manipulated variable of the actuator is corrected to cancel the change in gain. Thus, the influence of the alteration of a torque constant in accordance with the rocking angle can be suppressed so that the response characteristic becomes uniform all over a scanning region, and the positioning speed can be improved.Type: GrantFiled: August 31, 2004Date of Patent: September 18, 2007Assignee: Hitachi Via Mechanics Ltd.Inventors: Haruaki Otsuki, Souichi Toyama, Kenta Seki, Yaichi Okubo, Daisuke Kitamura
-
Publication number: 20070007828Abstract: A scanner has a rotor, and a stator disposed in the outside of the rotor. The rotor includes a shaft, and a permanent magnet mounted on the outer circumferential side of the shaft. The stator includes a casing, a yoke held in the inner circumferential side of the casing, and coils disposed in the inner circumferential side of the yoke. The permanent magnet of the rotor has radially depressed grooves formed in its outer circumferential portion. The torque constant of the scanner is circumferentially equalized by the grooves. Thus, positioning accuracy is improved.Type: ApplicationFiled: June 23, 2006Publication date: January 11, 2007Applicant: Hitachi Via Mechanics, Ltd.Inventors: Akira Doi, Haruaki Otsuki, Atsushi Sakamoto, Souichi Toyama, Yaichi Okubo
-
Publication number: 20060271232Abstract: There is provided a digital servo control unit which uses a D/A converter, which suppresses the spike-like pulsation superimposed on a current error signal inside a current control circuit, and which has control performance not lower than that in the background art even when a low-voltage and low-price power supply circuit is used. The digital servo control unit has a first-order low pass filter acting on an analog signal output by the D/A converter, and a stabilizing compensation means for compensating a phase delay caused by the first-order low pass filter. An output signal of the first-order low pass filter is input to a current control circuit as a current command signal. The first-order low pass filter is formed as a low pass filter having a cut-off frequency which is lower than a sampling frequency. The first-order low pass filter may be replaced by a notch filter having a cut-off frequency which is equal to a sampling frequency or which is equal to an integer multiple of a Nyquist frequency.Type: ApplicationFiled: May 30, 2006Publication date: November 30, 2006Applicant: Hitachi Via Mechanics, Ltd.Inventors: Souichi Toyama, Yaichi Okubo
-
Patent number: 7023598Abstract: An optical scanner which can realize target trajectory tracking machining at a high speed and with a high accuracy. In a servo control circuit controlling the operation of an X-axis scanner for positioning a mirror and the operation of a Y-axis scanner for positioning another mirror, sine wave response is performed at a specific frequency on feedback control for each axis so that the gain characteristic and the phase characteristic of the feedback control are estimated. This arithmetic operation processing is performed by a microprocessor prior to machining, and the results of estimation of the two axes are stored as data for each frequency. In the stage of machining, the results of estimation in terms of the gain characteristic and the phase characteristic are used for correcting the amplitude and phase of a sine wave of a target trajectory in order to cancel each characteristic.Type: GrantFiled: January 16, 2004Date of Patent: April 4, 2006Assignee: Hitachi Via Mechanics, Ltd.Inventors: Souichi Toyama, Atsushi Sakamoto, Haruaki Otsuki, Yaichi Okubo
-
Publication number: 20050184156Abstract: A optical scanner control method and a optical scanner capable of positioning a mirror at a high speed independently of a rocking angle, and a laser machining apparatus for irradiating a printed circuit board with a laser beam by use of the optical scanner to thereby perforate the printed circuit board. In order to operate an actuator for rocking the mirror based on a deviation of a current position from an commanded value, a change in gain of the actuator is measured in accordance with each rocking angle in advance, and the manipulated variable of the actuator is corrected to cancel the change in gain. Thus, the influence of the alteration of a torque constant in accordance with the rocking angle can be suppressed so that the response characteristic becomes uniform all over a scanning region, and the positioning speed can be improved.Type: ApplicationFiled: August 31, 2004Publication date: August 25, 2005Applicant: Hitachi Via Mechanics Ltd.Inventors: Haruaki Otsuki, Souichi Toyama, Kenta Seki, Yaichi Okubo, Daisuke Kitamura
-
Publication number: 20050187650Abstract: A difference between each position command data outputted in a form of a step signal from a high-level controller and its corresponding detected position data of a movable body is integrated by an integral compensator to position the movable body. Assuming, for example, that the movable body is a steerable mirror, digital filters are arranged to compensate the value of an initial state of an angular displacement and the value of an initial state of an angular velocity, respectively, and respective impulse responses of the digital filters as additional input elements are added to an output terminal of the integral compensator. For higher effectiveness, internal state variables of the digital filters can desirably be cleared to zero whenever an angle (position) command data is received.Type: ApplicationFiled: February 4, 2005Publication date: August 25, 2005Applicant: Hitachi Via Mechanics Ltd.Inventors: Souichi Toyama, Yaichi Okubo, Hiromu Hirai, Makoto Iwasaki, Motohiro Kawafuku, Noriaki Hirose
-
Publication number: 20050128553Abstract: A scanner system includes a servo control unit. A rotation angle of a rotating shaft supporting a mirror is detected, and an error of the detected value with respect to a commanded value is integrated by an integral compensator so that the detected value is able to track the commanded value. A tracking error proportional compensator is disposed in parallel with the integral compensator so as to add a correction value proportional to the error to the integrated value of the error. A plurality of gains are prepared for each of the integral compensator, the tracking error proportional compensator, a detected value proportional compensator and a detected value differential compensator of the servo control unit. Each gain is changed in accordance with a travel angle of the commanded value. Thus, the mirror can be positioned quickly so that the machining speed can be improved.Type: ApplicationFiled: August 27, 2004Publication date: June 16, 2005Applicant: Hitachi Via Mechanics Ltd.Inventors: Souichi Toyama, Haruaki Otsuki, Atsushi Sakamoto, Kenta Seki, Yaichi Okubo
-
Publication number: 20040212862Abstract: An optical scanner which can realize target trajectory tracking machining at a high speed and with a high accuracy. In a servo control circuit controlling the operation of an X-axis scanner for positioning a mirror and the operation of a Y-axis scanner for positioning another mirror, sine wave response is performed at a specific frequency on feedback control for each axis so that the gain characteristic and the phase characteristic of the feedback control are estimated. This arithmetic operation processing is performed by a microprocessor prior to machining, and the results of estimation of the two axes are stored as data for each frequency. In the stage of machining, the results of estimation in terms of the gain characteristic and the phase characteristic are used for correcting the amplitude and phase of a sine wave of a target trajectory in order to cancel each characteristic.Type: ApplicationFiled: January 16, 2004Publication date: October 28, 2004Applicant: Hitachi Via Mechanics, Ltd.Inventors: Souichi Toyama, Atsushi Sakamoto, Haruaki Otsuki, Yaichi Okubo
-
Patent number: 6703603Abstract: A controller for an optical scanner includes a mirror angle detecting unit for detecting an angle of a mirror, a rotation shaft angle detecting unit for detecting an angle of the shaft, a current detecting unit for detecting a current supplied to a motor, and a torsional vibration stabilizing compensation unit for stabilizing a torsional vibration of the shaft, thereby a value subjected to a proportional compensation and a differential compensation by using a rotation shaft angle detected value and a value from the torsional vibration stabilizing compensation unit are negatively fed back to a value obtained by integrally compensating for a tracking error between the angle desired value and a mirror angle detection value to determine a current value to be supplied to the motor.Type: GrantFiled: November 30, 2001Date of Patent: March 9, 2004Assignee: Hitachi Via Mechanics, Ltd.Inventors: Souichi Tohyama, Hiromu Hirai, Kichio Nakajima, Atsushi Sakamoto, Yaichi Okubo, Masahiro Oishi
-
Publication number: 20030102427Abstract: A controller for an optical scanner includes a mirror angle detecting unit for detecting an angle of a mirror, a rotation shaft angle detecting unit for detecting an angle of the shaft, a current detecting unit for detecting a current supplied to a motor, and a torsional vibration stabilizing compensation unit for stabilizing a torsional vibration of the shaft, thereby a value subjected to a proportional compensation and a differential compensation by using a rotation shaft angle detected value and a value from the torsional vibration stabilizing compensation unit are negatively fed back to a value obtained by integrally compensating for a tracking error between the angle desired value and a mirror angle detection value to determine a current value to be supplied to the motor.Type: ApplicationFiled: November 30, 2001Publication date: June 5, 2003Applicant: Hitachi Via Mechanics, Ltd.Inventors: Souichi Tohyama, Hiromu Hirai, Kichio Nakajima, Atsushi Sakamoto, Yaichi Okubo, Masahiro Oishi