Patents by Inventor Masaki Kamada
Masaki Kamada 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: 10903716Abstract: An electric working machine includes a motor, a circuit board having capacitors and choke coils for noise reduction, and a fixing tool for fixing the circuit board to a portion of a case of the motor including motor terminals for power feed. The circuit board includes input terminal members to receive an externally supplied driving power, and a ground connection member electrically coupled to the portion of the case. The capacitors couple the input terminal members to the ground connection member. The choke coils couple the input terminal members to the motor terminals. The ground connection member is arranged in a certain area of the circuit board, which is one of areas on the circuit board defined by dividing the circuit board with a straight line crossing a rotational shaft and is an area where the input terminal members are located. The capacitors are mounted in the certain area.Type: GrantFiled: September 19, 2018Date of Patent: January 26, 2021Assignee: MAKITA CORPORATIONInventors: Masaki Kamada, Fujio Nakano
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Publication number: 20190103784Abstract: An electric working machine includes a motor, a circuit board having capacitors and choke coils for noise reduction, and a fixing tool for fixing the circuit board to a portion of a case of the motor including motor terminals for power feed. The circuit board includes input terminal members to receive an externally supplied driving power, and a ground connection member electrically coupled to the portion of the case. The capacitors couple the input terminal members to the ground connection member. The choke coils couple the input terminal members to the motor terminals. The ground connection member is arranged in a certain area of the circuit board, which is one of areas on the circuit board defined by dividing the circuit board with a straight line crossing a rotational shaft and is an area where the input terminal members are located. The capacitors are mounted in the certain area.Type: ApplicationFiled: September 19, 2018Publication date: April 4, 2019Applicant: MAKITA CORPORATIONInventors: Masaki KAMADA, Fujio NAKANO
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Patent number: 8203509Abstract: A problem is to be solved that there is to be provided a plasma display device capable of generating driving signals with less variation in delay time and without carrying out any phase adjustment. There is provided a plasma display device including; a first display electrode; a second display electrode adapted to cause a discharge to occur between the first display electrode and the second display electrode; a first display electrode drive circuit for applying a discharge voltage to the first display electrode; and a second display electrode drive circuit for applying a discharge voltage to the second display electrode. The first display electrode drive circuit has a first output element for supplying a first electric potential to the first display electrode in accordance with a first input signal which is inputted by using a transformer.Type: GrantFiled: July 11, 2008Date of Patent: June 19, 2012Assignee: Hitachi, Ltd.Inventors: Makoto Onozawa, Tomokatsu Kishi, Hideaki Ohki, Masaki Kamada
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Patent number: 7773052Abstract: There is provided a plasma display device including a slope waveform generating circuit which supplies to an electrode a slope waveform of which voltage changes with the lapse of time, the electrode being formed in a capacitive load to serves as a display element in a display panel for displaying images, wherein the slope waveform generating circuit includes: a plurality of power supplies which supply different voltages; and a switching circuit which selects one power supply out of the a plurality of power supplies and supplies a voltage to the electrode, wherein the switching circuit switches the power supply, which supplies a voltage to the electrode, in accordance with a voltage being supplied to the electrode.Type: GrantFiled: September 5, 2006Date of Patent: August 10, 2010Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Masaki Kamada, Takashi Shiizaki
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Patent number: 7768480Abstract: A problem is to be solved that there is to be provided a plasma display device capable of generating driving signals with less variation in delay time and without carrying out any phase adjustment. There is provided a plasma display device including; a first display electrode; a second display electrode adapted to cause a discharge to occur between the first display electrode and the second display electrode; a first display electrode drive circuit for applying a discharge voltage to the first display electrode; and a second display electrode drive circuit for applying a discharge voltage to the second display electrode. The first display electrode drive circuit has a first output element for supplying a first electric potential to the first display electrode in accordance with a first input signal which is inputted by using a transformer.Type: GrantFiled: November 18, 2005Date of Patent: August 3, 2010Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Tomokatsu Kishi, Hideaki Ohki, Masaki Kamada
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Patent number: 7710042Abstract: A PDP apparatus comprises, in a circuit part, a ramp output device which outputs a ramp wave to electrodes of a PDP. The ramp output device has a ramp generator which generates and outputs a first ramp wave of which inclination is variable, an impedance conversion circuit which receives the first ramp wave as input and outputs a second ramp wave produced by impedance conversion, and a feedback circuit which receives the second ramp wave as input and feeds it back to the input of the ramp generator. The ramp generator outputs the second ramp wave as a ramp wave (output voltage). Techniques to realize output of stabilized ramp wave in a PDP apparatus so as to stabilize PDP display operations are provided.Type: GrantFiled: February 7, 2007Date of Patent: May 4, 2010Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Takashi Shiizaki, Masaki Kamada, Akihiro Machida, Sojiro Hagihara
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Publication number: 20080284685Abstract: A problem is to be solved that there is to be provided a plasma display device capable of generating driving signals with less variation in delay time and without carrying out any phase adjustment. There is provided a plasma display device including; a first display electrode; a second display electrode adapted to cause a discharge to occur between the first display electrode and the second display electrode; a first display electrode drive circuit for applying a discharge voltage to the first display electrode; and a second display electrode drive circuit for applying a discharge voltage to the second display electrode. The first display electrode drive circuit has a first output element for supplying a first electric potential to the first display electrode in accordance with a first input signal which is inputted by using a transformer.Type: ApplicationFiled: July 11, 2008Publication date: November 20, 2008Applicant: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Tomokatsu Kishi, Hideaki Ohki, Masaki Kamada
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Publication number: 20080025057Abstract: A PDP apparatus comprises, in a circuit part, a ramp output device which outputs a ramp wave to electrodes of a PDP. The ramp output device has a ramp generator which generates and outputs a first ramp wave of which inclination is variable, an impedance conversion circuit which receives the first ramp wave as input and outputs a second ramp wave produced by impedance conversion, and a feedback circuit which receives the second ramp wave as input and feeds it back to the input of the ramp generator. The ramp generator outputs the second ramp wave as a ramp wave (output voltage). Techniques to realize output of stabilized ramp wave in a PDP apparatus so as to stabilize PDP display operations are provided.Type: ApplicationFiled: February 7, 2007Publication date: January 31, 2008Inventors: Takashi Shiizaki, Masaki Kamada, Akihiro Machida, Sojiro Hagihara
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Patent number: 7242399Abstract: A low-cost capacitive load drive circuit, in which a reference voltage, a first voltage, and a second voltage are supplied to a capacitive load, and a plasma display apparatus using it, have been disclosed. The capacitive load drive circuit comprises a reference voltage switch the breakdown voltage of which is properly adjusted, a first switch, a reference voltage phase adjusting circuit, and a first phase adjusting circuit, and malfunctions due to the difference in switching characteristics can be prevented from occurring even when devices of different breakdown voltages are used.Type: GrantFiled: November 19, 2002Date of Patent: July 10, 2007Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Hideaki Ohki, Masaki Kamada, Kazuyoshi Yamada, Eiji Ito
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Patent number: 7230587Abstract: In a plasma display device having a reduced discharge-current-induced voltage fluctuation and an expanded drive margin and being successful in preventing the display characteristics from being degraded, a Y-electrode drive circuit and an X-electrode drive circuit for supplying a drive voltage to the capacitance which represents a display cell are configured using parallel circuits in which first switching elements having a high-speed-switching performance and second switching elements having a low-saturation-voltage performance are connected in parallel, so that the second switching elements having the low-saturation-voltage performance are turned on at least during a period that discharge current flows therebetween.Type: GrantFiled: February 19, 2004Date of Patent: June 12, 2007Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Hideaki Ohki, Masaki Kamada, Takashi Shiizaki
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Publication number: 20070057870Abstract: There is provided a plasma display device including a slope waveform generating circuit which supplies to an electrode a slope waveform of which voltage changes with the lapse of time, the electrode being formed in a capacitive load to serves as a display element in a display panel for displaying images, wherein the slope waveform generating circuit includes: a plurality of power supplies which supply different voltages; and a switching circuit which selects one power supply out of the a plurality of power supplies and supplies a voltage to the electrode, wherein the switching circuit switches the power supply, which supplies a voltage to the electrode, in accordance with a voltage being supplied to the electrode.Type: ApplicationFiled: September 5, 2006Publication date: March 15, 2007Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Masaki Kamada, Takashi Shiizaki
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Publication number: 20060132391Abstract: A problem is to be solved that there is to be provided a plasma display device capable of generating driving signals with less variation in delay time and without carrying out any phase adjustment. There is provided a plasma display device including; a first display electrode; a second display electrode adapted to cause a discharge to occur between the first display electrode and the second display electrode; a first display electrode drive circuit for applying a discharge voltage to the first display electrode; and a second display electrode drive circuit for applying a discharge voltage to the second display electrode. The first display electrode drive circuit has a first output element for supplying a first electric potential to the first display electrode in accordance with a first input signal which is inputted by using a transformer.Type: ApplicationFiled: November 18, 2005Publication date: June 22, 2006Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Makoto Onozawa, Tomokatsu Kishi, Hideaki Ohki, Masaki Kamada
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Publication number: 20040222747Abstract: In a plasma display device having a reduced discharge-current-induced voltage fluctuation and an expanded drive margin and being successful in preventing the display characteristics from being degraded, a Y-electrode drive circuit and an X-electrode drive circuit for supplying a drive voltage to the capacitance which represents a display cell are configured using parallel circuits in which first switching elements having a high-speed-switching performance and second switching elements having a low-saturation-voltage performance are connected in parallel, so that the second switching elements having the low-saturation-voltage performance are turned on at least during a period that discharge current flows therebetween.Type: ApplicationFiled: February 19, 2004Publication date: November 11, 2004Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Makoto Onozawa, Hideaki Ohki, Masaki Kamada, Takashi Shiizaki
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Patent number: 6781322Abstract: A capacitive load circuit and a plasma display apparatus using such a circuit, being able to use a sustain transistor having a voltage rating in accordance with a sustain voltage even when a voltage larger than the sustain voltage is applied to a sustain electrode, have been disclosed, wherein a switch whose one end is connected to a capacitive load is comprised and when a third voltage, whose voltage difference from a second voltage is larger than the voltage difference between a first voltage and the second voltage, is applied to the capacitive load, a fourth voltage is selectively applied to the other end of the switch.Type: GrantFiled: January 22, 2003Date of Patent: August 24, 2004Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Eiji Ito, Ken Kumakura, Hideaki Ohki, Masaki Kamada, Kazuyoshi Yamada
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Publication number: 20030214244Abstract: A capacitive load circuit and a plasma display apparatus using such a circuit, being able to use a sustain transistor having a voltage rating in accordance with a sustain voltage even when a voltage larger than the sustain voltage is applied to a sustain electrode, have been disclosed, wherein a switch whose one end is connected to a capacitive load is comprised and when a third voltage, whose voltage difference from a second voltage is larger than the voltage difference between a first voltage and the second voltage, is applied to the capacitive load, a fourth voltage is selectively applied to the other end of the switch.Type: ApplicationFiled: January 22, 2003Publication date: November 20, 2003Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Makoto Onozawa, Eiji Ito, Ken Kumakura, Hideaki Ohki, Masaki Kamada, Kazuyoshi Yamada
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Publication number: 20030184539Abstract: A low-cost capacitive load drive circuit, in which a reference voltage, a first voltage, and a second voltage are supplied to a capacitive load, and a plasma display apparatus using it, have been disclosed. The capacitive load drive circuit comprises a reference voltage switch the breakdown voltage of which is properly adjusted, a first switch, a reference voltage phase adjusting circuit, and a first phase adjusting circuit, and malfunctions due to the difference in switching characteristics can be prevented from occurring even when devices of different breakdown voltages are used.Type: ApplicationFiled: November 19, 2002Publication date: October 2, 2003Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Makoto Onozawa, Hideaki Ohki, Masaki Kamada, Kazuyoshi Yamada, Eiji Ito