Patents by Inventor Sumiaki Aoki
Sumiaki Aoki 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: 8944560Abstract: An image forming apparatus includes: a recording head including multiple nozzles and multiple piezoelectric elements that generate pressure for causing droplets to be ejected from the nozzles; a driving-waveform generating unit that generates a driving waveform to be applied to the piezoelectric elements; first switching devices each disposed between the driving-waveform generating unit and respective one of the piezoelectric elements; second switching devices each disposed between a predetermined voltage and respective one of the piezoelectric elements; and a slight-vibration control unit. The slight-vibration control unit causes slight vibrations to be applied to a non-ejection nozzle by placing the second switch device for the non-ejection nozzle in a conduction state, and, when a predetermined period of time has elapsed after shift to the conduction state, placing the second switch device in a non-conduction state and the first switch device for the non-ejection nozzle in a conduction state.Type: GrantFiled: March 13, 2013Date of Patent: February 3, 2015Assignee: Ricoh Company, LimitedInventors: Sumiaki Aoki, Kohta Akiyama
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Patent number: 8602515Abstract: An image forming device includes a liquid discharge head including piezoelectric elements; a drive waveform generating unit that outputs a drive waveform; a selection unit that applies the drive waveform to the piezoelectric elements; a resonant frequency adjusting circuit that is connected in parallel with the piezoelectric elements; a switch unit that switches the resonant frequency adjusting circuit; and a switching control unit that causes the switch unit to switch in accordance with a first number of simultaneously driven piezoelectric elements. When the first number of the simultaneously driven piezoelectric elements is greater than a predetermined number, the switching control unit connects the resonant frequency adjusting circuit, so that a resonant frequency of a closed loop becomes lower than a resonant frequency of the closed loop when the first number of the simultaneously driven piezoelectric elements is less than the predetermined number.Type: GrantFiled: February 22, 2012Date of Patent: December 10, 2013Assignee: Ricoh Company, Ltd.Inventors: Kaoru Satoh, Sumiaki Aoki
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Publication number: 20130241986Abstract: An image forming apparatus includes: a recording head including multiple nozzles and multiple piezoelectric elements that generate pressure for causing droplets to be ejected from the nozzles; a driving-waveform generating unit that generates a driving waveform to be applied to the piezoelectric elements; first switching devices each disposed between the driving-waveform generating unit and respective one of the piezoelectric elements; second switching devices each disposed between a predetermined voltage and respective one of the piezoelectric elements; and a slight-vibration control unit. The slight-vibration control unit causes slight vibrations to be applied to a non-ejection nozzle by placing the second switch device for the non-ejection nozzle in a conduction state, and, when a predetermined period of time has elapsed after shift to the conduction state, placing the second switch device in a non-conduction state and the first switch device for the non-ejection nozzle in a conduction state.Type: ApplicationFiled: March 13, 2013Publication date: September 19, 2013Applicant: Ricoh Company, LimitedInventors: Sumiaki AOKI, Kohta AKIYAMA
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Publication number: 20120229541Abstract: An image forming device includes a liquid discharge head including piezoelectric elements; a drive waveform generating unit that outputs a drive waveform; a selection unit that applies the drive waveform to the piezoelectric elements; a resonant frequency adjusting circuit that is connected in parallel with the piezoelectric elements; a switch unit that switches the resonant frequency adjusting circuit; and a switching control unit that causes the switch unit to switch in accordance with a first number of simultaneously driven piezoelectric elements. When the first number of the simultaneously driven piezoelectric elements is greater than a predetermined number, the switching control unit connects the resonant frequency adjusting circuit, so that a resonant frequency of a closed loop becomes lower than a resonant frequency of the closed loop when the first number of the simultaneously driven piezoelectric elements is less than the predetermined number.Type: ApplicationFiled: February 22, 2012Publication date: September 13, 2012Applicant: RICOH COMPANY, LTD.Inventors: Kaoru SATOH, Sumiaki AOKI
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Patent number: 7494199Abstract: There is provided a head control device able to re-charge an electromechanical transducing element with a driving pulse without requiring an additional re-charging time period in a recording period. The driving signal includes a plurality of driving pulses, and in each recording period, at least one driving pulse includes a portion varying from a discharging level to a medium level to charge the piezoelectric element to eject a liquid droplet, and a subsequent portion varying from the medium level to a target level to re-charge the piezoelectric element to the target level.Type: GrantFiled: June 20, 2003Date of Patent: February 24, 2009Assignee: Ricoh Company, Ltd.Inventor: Sumiaki Aoki
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Publication number: 20050237350Abstract: There is provided a head control device able to re-charge an electromechanical transducing element with a driving pulse without requiring an additional re-charging time period in a recording period. The driving signal includes a plurality of driving pulses, and in each recording period, at least one driving pulse. includes a portion varying from a discharging level to a medium level to charge the piezoelectric element to eject a liquid droplet, and a subsequent portion varying from the medium level to a target level to re-charge the piezoelectric element to the target level.Type: ApplicationFiled: June 20, 2003Publication date: October 27, 2005Inventor: Sumiaki Aoki
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Patent number: 6923520Abstract: A head driving unit the generates a driving waveform, each driving waveform including a plurality of driving pulses, and selects one or more driving pulses to be applied to a liquid drop discharging head in response to data corresponding to an image. By selecting a plurality of selection signals that defines the driving pulses to be applied to the liquid discharging head, the head driving unit can change a recording density or record multiple value images.Type: GrantFiled: June 14, 2002Date of Patent: August 2, 2005Assignee: Ricoh Company, Ltd.Inventors: Tatsuhiko Oikawa, Toshihito Kamei, Takashi Kimura, Sumiaki Aoki, Mikio Ohashi
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Publication number: 20030011653Abstract: A head driving unit the generates a driving waveform, each driving waveform including a plurality of driving pulses, and selects one or more driving pulses to be applied to a liquid drop discharging head in response to data corresponding to an image. By selecting a plurality of selection signals that defines the driving pulses to be applied to the liquid discharging head, the head driving unit can change a recording density or record multiple value images.Type: ApplicationFiled: June 14, 2002Publication date: January 16, 2003Applicant: Ricoh Company, Ltd,Inventors: Tatsuhiko Oikawa, Toshihito Kamei, Takashi Kimura, Sumiaki Aoki, Mikio Ohashi
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Patent number: 6252682Abstract: A document sensing device for an image forming apparatus of the present invention is capable of sensing a document stably without being influenced by disturbing light, e.g., light ascribable to fluorescent lamps or similar illuminators illuminating a room. According to one aspect of die invention, optical elements are held by a jig rotatable about an optical axis. According to another aspect of the invention, a light receiving means or a photosensor means has at least four light-sensitive regions.Type: GrantFiled: May 1, 1998Date of Patent: June 26, 2001Assignee: Ricoh Company, Ltd.Inventors: Nobuyuki Baba, Koichi Kudo, Sumiaki Aoki
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Patent number: 5929436Abstract: An original placement table is provided, on which an original sheet is placed. An original scanning device causes a light beam to scan the original sheet placed on the original placement table. A light receiving device receives a light beam which has been reflected by the original sheet placed on the original placement table after being emitted by the original scanning device. An original edge determining device monitors light intensity of the light beam received by the light receiving device. The original edge determining device determines that the light beam currently being received by the light receiving device is the light beam reflected by an edge of the original sheet placed on the original placement table when a significant variation is detected in the light intensity either for the first time or for the last time in one scanning operation of the original scanning device.Type: GrantFiled: August 18, 1997Date of Patent: July 27, 1999Assignee: Ricoh Company, Ltd.Inventors: Nobuyuki Baba, Toshiharu Murai, Sumiaki Aoki, Koichi Kudo
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Patent number: 5818062Abstract: An original placement table is provided, on which an original sheet is placed. An original scanning device causes a light beam to scan the original sheet placed on the original placement table. A light receiving device receives a light beam which has been reflected by the original sheet placed on the original placement table after being emitted by the original scanning device. An original edge determining device monitors light intensity of the light beam received by the light receiving device. The original edge determining device determines that the light beam currently being received by the light receiving device is the light beam reflected by an edge of the original sheet placed on the original placement table when a significant variation is detected in the light intensity either for the first time or for the last time in one scanning operation of the original scanning device.Type: GrantFiled: August 18, 1997Date of Patent: October 6, 1998Assignee: Ricoh Company, Ltd.Inventors: Nobuyuki Baba, Toshiharu Murai, Sumiaki Aoki, Koichi Kudo
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Patent number: 5729024Abstract: An original placement table is provided, on which an original sheet is placed. An original scanning device causes a light beam to scan the original sheet placed on the original placement table. A light receiving device receives a light beam which has been reflected by the original sheet placed on the original placement table after being emitted by the original scanning device. An original edge determining device monitors light intensity of the light beam received by the light receiving device. The original edge determining device determines that the light beam currently being received by the light receiving device is the light beam reflected by an edge of the original sheet placed on the original placement table when a significant variation is detected in the light intensity either for the first time or for the last time in one scanning operation of the original scanning device.Type: GrantFiled: May 1, 1996Date of Patent: March 17, 1998Assignee: Ricoh Company, Ltd.Inventors: Nobuyuki Baba, Toshiharu Murai, Sumiaki Aoki, Koichi Kudo