Patents by Inventor Tetsuya Ohta
Tetsuya Ohta 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: 11709443Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a transfer member, a voltage source for applying a voltage to the transfer member, a detecting portion for detecting a current flowing through the transfer member, and a controller for carrying out constant-voltage control so that the voltage applied to the transfer member becomes a target voltage when a recording material P passes through a transfer portion. The controller is capable of changing the voltage applied to the transfer member so that a detection result detected by the detecting portion during transfer falls within a predetermined range. The controller changes the predetermined range on the basis of the detection result detected by the detecting portion when the voltage is applied to the transfer member in a state in which the recording material P is absent in the transfer portion.Type: GrantFiled: February 25, 2022Date of Patent: July 25, 2023Assignee: Canon Kabushiki KaishaInventors: Yutaka Kakehi, Tetsuya Ohta, Yusuke Minato
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Publication number: 20220276590Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a transfer member, a voltage source for applying a voltage to the transfer member, a detecting portion for detecting a current flowing through the transfer member, and a controller for carrying out constant-voltage control so that the voltage applied to the transfer member becomes a target voltage when a recording material P passes through a transfer portion. The controller is capable of changing the voltage applied to the transfer member so that a detection result detected by the detecting portion during transfer falls within a predetermined range. The controller changes the predetermined range on the basis of the detection result detected by the detecting portion when the voltage is applied to the transfer member in a state in which the recording material P is absent in the transfer portion.Type: ApplicationFiled: February 25, 2022Publication date: September 1, 2022Inventors: Yutaka Kakehi, Tetsuya Ohta, Yusuke Minato
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Patent number: 11281130Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a transfer member, a voltage source for applying a voltage to the transfer member, a detecting portion for detecting a current flowing through the transfer member, and a controller for carrying out constant-voltage control so that the voltage applied to the transfer member becomes a target voltage when a recording material P passes through a transfer portion. The controller is capable of changing the voltage applied to the transfer member so that a detection result detected by the detecting portion during transfer falls within a predetermined range. The controller changes the predetermined range on the basis of the detection result detected by the detecting portion when the voltage is applied to the transfer member in a state in which the recording material P is absent in the transfer portion.Type: GrantFiled: November 19, 2020Date of Patent: March 22, 2022Assignee: Canon Kabushiki KaishaInventors: Yutaka Kakehi, Tetsuya Ohta, Yusuke Minato
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Patent number: 11143989Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a current detecting portion, a controller, and a receiving portion. During the recording material passing through the transfer portion, the controller controls a voltage applied to a transfer member on the basis of a detection result of the current detecting portion so that a current flowing through the transfer member falls within a predetermined range. The controller sets at least one of an upper limit and a lower limit of the predetermined range on the basis of a predetermined voltage changing instruction received by the receiving portion.Type: GrantFiled: July 31, 2019Date of Patent: October 12, 2021Assignee: Canon Kabushiki KaishaInventors: Tetsuya Ohta, Yutaka Kakehi, Toshiyuki Yamada
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Publication number: 20210072673Abstract: An information which includes an image bearing member 1, an intermediary transfer belt 7, a transfer member 8, a voltage source 20 for applying a voltage to the transfer member 8, a detecting portion 21 for detecting a current flowing through the transfer member 8, and a controller 50 for carrying out constant-voltage control so that the voltage applied to the transfer member when a recording material P passes through a transfer portion N2 and in which the controller 50 is capable of changing the voltage applied to the transfer member 8 so that a detection result detected by the detecting portion 21 during transfer falls within a predetermined pass has a constitution in which said controller 50 changes the predetermined range on the basis of the detection result detected by the detecting portion 21 when the voltage is applied to the transfer member 8 in a state in which the recording material P is absent in the transfer portion N2.Type: ApplicationFiled: November 19, 2020Publication date: March 11, 2021Inventors: Yutaka Kakehi, Tetsuya Ohta, Yusuke Minato
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Publication number: 20200050133Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a current detecting portion, a controller, and a receiving portion. During the recording material being passing through the transfer portion, the controller controls a voltage applied to a transfer member on the basis of a detection result of the current detecting portion so that a current flowing through the transfer member falls within a predetermined range. The controller sets at least one of an upper limit and a lower limit of the predetermined range on the basis of a predetermined voltage changing instruction received by the receiving portion.Type: ApplicationFiled: July 31, 2019Publication date: February 13, 2020Inventors: Tetsuya Ohta, Yutaka Kakehi, Toshiyuki Yamada
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Patent number: 10048625Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a primary transfer roller provided so that a contact region between the roller and the belt and a contact region between the image bearing member and the belt are in a non-overlapping state with each other with respect to a movement direction of the belt, a primary transfer voltage source, a current detecting portion, an executing portion configured to acquire information on a discharge start voltage on the basis of a detection result of the detecting portion in a period other than a period of primary transfer by applying the voltage to the roller and a setting portion configured to set, on the basis of an execution result of the executing portion, a primary transfer voltage applied to the roller by the primary transfer voltage source in the period of the primary transfer.Type: GrantFiled: May 11, 2017Date of Patent: August 14, 2018Assignee: Canon Kabushiki KaishaInventors: Tetsuya Ohta, Tohru Nakaegawa
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Publication number: 20170336738Abstract: An image forming apparatus includes an image bearing member, an intermediary transfer belt, a primary transfer roller provided so that a contact region between the roller and the belt and a contact region between the image bearing member and the belt are in a non-overlapping state with each other with respect to a movement direction of the belt, a primary transfer voltage source, a current detecting portion, an executing portion configured to acquire information on a discharge start voltage on the basis of a detection result of the detecting portion in a period other than a period of primary transfer by applying the voltage to the roller; and a setting portion configured to set, on the basis of an execution result of the executing portion, a primary transfer voltage applied to the roller by the primary transfer voltage source in the period of the primary transfer.Type: ApplicationFiled: May 11, 2017Publication date: November 23, 2017Inventors: Tetsuya Ohta, Tohru Nakaegawa
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Patent number: 9740146Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a speed setting portion, a test mode executing portion, a renewing mode executing portion, and a setting portion for setting a voltage applied to the transfer member. In a period in which the toner image exists at the transfer portion when image formation is executed at a first speed, the setting portion sets the voltage applied to the transfer member at a first target voltage last renewed. In a period in which the toner image exists at the transfer portion when the image formation is executed at a second speed, the setting portion sets the voltage applied to the transfer member at a voltage on the basis of the first target voltage last renewed and a conversion coefficient last renewed.Type: GrantFiled: January 15, 2016Date of Patent: August 22, 2017Assignee: CANON KABUSHIKI KAISHAInventor: Tetsuya Ohta
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Patent number: 9557695Abstract: An image forming apparatus includes an image bearing member, a voltage source, a fixing device including a rotatable member, an executing portion for executing an operation in a both side mode, and a setting portion. The setting portion sets a transfer voltage in the operation for a second surface so that an absolute value of the transfer voltage when a recording material region, which starts from a most downstream end position and which passed through a fixing portion through a first one full circumference of the rotatable member when the toner image is fixed on a first surface passes through the transfer portion, is greater than an absolute value of the transfer voltage when a recording material region passed through the fixing portion through a second one full circumference of the rotatable member when the toner image is fixed on the first surface passes through the transfer portion.Type: GrantFiled: August 6, 2015Date of Patent: January 31, 2017Assignee: Canon Kabushiki KaishaInventors: Etsuji Kojima, Tetsuya Ohta
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Patent number: 9454109Abstract: An image forming apparatus includes: an image bearing member; a toner image forming unit; a belt member; a transfer member; a transfer voltage source for generating a voltage applied to the transfer member; an obtaining portion for obtaining information on an electric resistance of the belt member; a detecting member for optically detecting a test toner image formed on the image bearing member and transferred on the belt member; and an executing portion for executing, on the basis of a detection result of the test toner image by the detecting member, an adjusting operation for adjusting an image forming condition of the toner image forming unit. The executing portion sets, on the basis of the information, a voltage applied to the transfer member when the test toner image is transferred onto the belt member in the adjusting operation.Type: GrantFiled: August 31, 2015Date of Patent: September 27, 2016Assignee: Canon Kabushiki KaishaInventors: Etsuji Kojima, Tetsuya Ohta
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Publication number: 20160209792Abstract: An image forming apparatus includes an image bearing member, a transfer member, a voltage source, a speed setting portion, a test mode executing portion, a renewing mode executing portion, and a setting portion for setting a voltage applied to the transfer member, in a period in which the toner image exists at the transfer portion when image formation is executed at a first speed, at a first target voltage last renewed and for setting the voltage applied to the transfer member, in a period in which the toner image exists at the transfer portion when the image formation is executed at a second speed, at a voltage on the basis of the first target voltage last renewed and a conversion coefficient last renewed.Type: ApplicationFiled: January 15, 2016Publication date: July 21, 2016Inventor: Tetsuya Ohta
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Publication number: 20160202652Abstract: An image forming apparatus includes a movable image bearing member, a transfer member, a constant voltage source for applying a transfer voltage and a returning voltage to the transfer member, an executing portion capable of selectively executing an operation in a first mode in which image formation is executed at a first speed and an operation in a second mode in which the image formation is effected at a speed slower than the first speed, and a setting portion for setting a falling time from transfer voltage falling start timing toward the returning voltage until a current flowing through said transfer member is zero. The setting portion sets the falling time in the operation in the second mode so as to be longer than the falling time in the operation in the first mode.Type: ApplicationFiled: December 21, 2015Publication date: July 14, 2016Inventor: Tetsuya Ohta
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Patent number: 9372462Abstract: An image forming apparatus includes a movable image bearing member, a transfer member, a constant voltage source for applying a transfer voltage and a returning voltage to the transfer member, an executing portion capable of selectively executing an operation in a first mode in which image formation is executed at a first speed and an operation in a second mode in which the image formation is effected at a speed slower than the first speed, and a setting portion for setting a falling time from transfer voltage falling start timing toward the returning voltage until a current flowing through said transfer member is zero. The setting portion sets the falling time in the operation in the second mode so as to be longer than the falling time in the operation in the first mode.Type: GrantFiled: December 21, 2015Date of Patent: June 21, 2016Assignee: CANON KABUSHIKI KAISHAInventor: Tetsuya Ohta
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Publication number: 20160077468Abstract: An image forming apparatus includes: an image bearing member; a toner image forming unit; a belt member; a transfer member; a transfer voltage source for generating a voltage applied to the transfer member; an obtaining portion for obtaining information on an electric resistance of the belt member; a detecting member for optically detecting a test toner image formed on the image bearing member and transferred on the belt member; and an executing portion for executing, on the basis of a detection result of the test toner image by the detecting member, an adjusting operation for adjusting an image forming condition of the toner image forming unit. The executing portion sets, on the basis of the information, a voltage applied to the transfer member when the test toner image is transferred onto the belt member in the adjusting operation.Type: ApplicationFiled: August 31, 2015Publication date: March 17, 2016Inventors: Etsuji Kojima, Tetsuya Ohta
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Publication number: 20160041510Abstract: An image forming apparatus includes: an image bearing member; a voltage source; a fixing device including a rotatable member; an executing portion for executing an operation in a both-side mode; and a setting portion. The setting portion sets a transfer voltage in the operation for a second surface so that an absolute value of the transfer voltage when a recording material region which starts from a downstreammost end position and which passed through a fixing portion through first one full circumference of the rotatable member when the toner image is fixed on a first surface passes through the transfer portion is larger than an absolute value of the transfer voltage when a recording material region passed through the fixing portion through second one full circumference of the rotatable member when the toner image is fixed on the first surface passes through the transfer portion.Type: ApplicationFiled: August 6, 2015Publication date: February 11, 2016Inventors: Etsuji Kojima, Tetsuya Ohta
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Patent number: 3935166Abstract: A linear aromatic polyester comprising, in the polymer molecule, at least 50 mole % of a repeating unit being represented by the formula ##SPC1##In whichR.sub.1 and R.sub.2 are the same or different and represent an alkyl group of 1-3 carbons, n is an integer of 1-6, X is a halogen atom and m is 0, 1 or 2,With an intrinsic viscosity of 0.3 or more when measured at 35.degree.C. by use of orthochlorophenol as a solvent.Type: GrantFiled: August 22, 1974Date of Patent: January 27, 1976Assignee: Teijin LimitedInventors: Tamaki Kanai, Takashi Yamagishi, Tetsuya Ohta, Hiroatsu Moriyama