Patents by Inventor Yoshie Iwakura
Yoshie Iwakura 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: 9025994Abstract: An image forming apparatus includes an image bearing member to bear a latent image on a surface thereof, a developing device to develop the latent image with toner, an intermediate transfer member, a secondary transfer member, a cleaning device, and a main body. The cleaning device cleans the secondary transfer member for a predetermined time period T1 during a startup operation after printing is completed normally before subsequent printing. The main body houses the image bearing member, the developing device, the intermediate transfer member, the secondary transfer member, and the cleaning device. At least one of the image bearing member and the developing device constitutes a process cartridge detachably attachable relative to the main body, and in a case in which the process cartridge is installed in the main body, the cleaning device cleans the secondary transfer member for a time period T2 extended from the predetermined time period T1.Type: GrantFiled: November 21, 2013Date of Patent: May 5, 2015Assignee: Ricoh Company, Ltd.Inventors: Takeshi Yamashita, Yoshie Iwakura, Yasuhiro Fujiwara
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Patent number: 8983323Abstract: Provided is a color image forming apparatus that includes: image carriers that form toner image of black and other colors; an intermediate transfer body that makes contact with the image carriers; and transfer units that transfer the toner images on the image carriers to the intermediate transfer body. A line velocity difference is set between the image carriers and the intermediate transfer body. An accelerated cohesion degree of toner is equal to or larger than 54%. A linear velocity difference X1 between the image carrier for black and the intermediate transfer body satisfies a relation of 0<X1?1.2 mm/sec. A linear velocity difference X2 between the image carriers for the colors and the intermediate transfer body satisfies a relation of 2.1?X2?4.0 mm/sec.Type: GrantFiled: January 25, 2013Date of Patent: March 17, 2015Assignee: Ricoh Company, LimitedInventors: Takeshi Yamashita, Yuji Nagatomo, Naoki Nakatake, Yasuhiro Fujiwara, Takafumi Miyazaki, Yasuhide Matsuno, Takahiro Sanada, Rumi Miyazaki, Kyoko Abe, Tomoya Adachi, Yoshie Iwakura
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Publication number: 20140153955Abstract: An image forming apparatus includes an image bearing member to bear a latent image on a surface thereof, a developing device to develop the latent image with toner, an intermediate transfer member, a secondary transfer member, a cleaning device, and a main body. The cleaning device cleans the secondary transfer member for a predetermined time period T1 during a startup operation after printing is completed normally before subsequent printing. The main body houses the image bearing member, the developing device, the intermediate transfer member, the secondary transfer member, and the cleaning device. At least one of the image bearing member and the developing device constitutes a process cartridge detachably attachable relative to the main body, and in a case in which the process cartridge is installed in the main body, the cleaning device cleans the secondary transfer member for a time period T2 extended from the predetermined time period T1.Type: ApplicationFiled: November 21, 2013Publication date: June 5, 2014Inventors: Takeshi YAMASHITA, Yoshie Iwakura, Yasuhiro Fujiwara
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Publication number: 20130195487Abstract: Provided is a color image forming apparatus that includes: image carriers that form toner image of black and other colors; an intermediate transfer body that makes contact with the image carriers; and transfer units that transfer the toner images on the image carriers to the intermediate transfer body. A line velocity difference is set between the image carriers and the intermediate transfer body. An accelerated cohesion degree of toner is equal to or larger than 54%. A linear velocity difference X1 between the image carrier for black and the intermediate transfer body satisfies a relation of 0<X1?1.2 mm/sec. A linear velocity difference X2 between the image carriers for the colors and the intermediate transfer body satisfies a relation of 2.1?X2?4.0 mm/sec.Type: ApplicationFiled: January 25, 2013Publication date: August 1, 2013Inventors: Takeshi YAMASHITA, Yuji NAGATOMO, Naoki NAKATAKE, Yasuhiro FUJIWARA, Takafumi MIYAZAKI, Yasuhide MATSUNO, Takahiro SANADA, Rumi MIYAZAKI, Kyoko ABE, Tomoya ADACHI, Yoshie IWAKURA
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Patent number: 8472817Abstract: An image forming apparatus including at least one latent image carrier, an image forming unit to form a toner image on the at least one latent image carrier based on image data, a transfer body onto which the toner image formed on the at least one latent image carrier is transferred in one or more valid image ranges, a non-image range determiner to determine a non-image range on a surface of the transfer body onto which the toner image is not transferred, a surface detector to detect the surface of the transfer body in the non-image range, and a toner determiner to determine whether or not toner is present in the non-image range based on a result detected by the surface detector.Type: GrantFiled: July 26, 2010Date of Patent: June 25, 2013Assignee: Ricoh Company, LimitedInventors: Rumi Konishi, Yoshie Iwakura, Yoshinori Shirasaki
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Publication number: 20110026943Abstract: An image forming apparatus including at least one latent image carrier, an image forming unit to form a toner image on the at least one latent image carrier based on image data, a transfer body onto which the toner image formed on the at least one latent image carrier is transferred in one or more valid image ranges, a non-image range determiner to determine a non-image range on a surface of the transfer body onto which the toner image is not transferred, a surface detector to detect the surface of the transfer body in the non-image range, and a toner determiner to determine whether or not toner is present in the non-image range based on a result detected by the surface detector.Type: ApplicationFiled: July 26, 2010Publication date: February 3, 2011Inventors: Rumi KONISHI, Yoshie Iwakura, Yoshinori Shirasaki
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Patent number: 7796919Abstract: For an electrostatic latent image formed on an image carrier (31b), besides an operation forming an “image forming electrostatic latent image” used to form the primary image, an operation is executed that forms an “electrostatic latent image for removing developer” for removing developer that resides on a developer supply member (53a) for a predetermined time period onto the image carrier (31b). Thus, developer is nearly eliminated from residing on this developer supply member (53a) in an overcharged state for a long period of time, and generation of a fogged image is avoided as much as possible.Type: GrantFiled: May 17, 2004Date of Patent: September 14, 2010Assignee: Sharp Kabushiki KaishaInventors: Susumu Murakami, Yoshiaki Kojoh, Takahisa Narikiyo, Kuniaki Nakano, Yoshie Iwakura
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Patent number: 7734235Abstract: In an image forming apparatus, an intermediate transfer belt is made of a resin film and is supported by a plurality of rollers. A driving roller that is one of the plurality of rollers, drives the intermediate transfer belt, and also functions as an opposing unit with respect to a secondary transfer roller. The driving roller is made of metal, and applies a bias to at least secondary transfer units, at least at a time of performing primary transfer to a plurality of image bearing bodies.Type: GrantFiled: March 9, 2006Date of Patent: June 8, 2010Assignee: Ricoh Company, Ltd.Inventors: Atsushi Takehara, Akihiro Kawasaki, Yoshie Iwakura, Tomoya Adachi, Takafumi Miyazaki
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Patent number: 7636539Abstract: An image forming unit includes four photoconductors, a belt extended around a driving roller and an extension-cum-primary transfer roller. Three primary transfer rollers sandwich the belt in association with a corresponding photoconductor. The extension-cum-primary transfer roller serves both as an extension roller and a primary transfer roller.Type: GrantFiled: April 26, 2006Date of Patent: December 22, 2009Assignee: Ricoh Company LimitedInventors: Akihiro Kawasaki, Atsushi Takehara, Yoshie Iwakura, Takafumi Miyazaki, Tomoya Adachi
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Patent number: 7587159Abstract: Provided is an image forming method that comprises a charging step, an exposing step, a developing step, an intermediate transfer step and a secondary transfer step, wherein the diameter R (mm) of a secondary transfer roller used in the secondary transfer step and the distance A (mm) between a nip center of the secondary transfer roller and a site where paper contacts with a secondary transfer belt at ingress side satisfy the following relation, and the charge amount Q (?C/g) of the toner going into the secondary transfer step satisfies the following relation. R/40<A<R/15 15/A2<Q<35/A2.Type: GrantFiled: September 14, 2007Date of Patent: September 8, 2009Assignee: Ricoh Company, Ltd.Inventors: Kazuoki Fuwa, Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Kato, Yoshitaka Sekiguchi, Yoshie Iwakura
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Patent number: 7428400Abstract: A primary transfer unit includes transfer units for performing a toner transfer from image carriers onto a transfer belt. Each of the transfer units is formed with a metallic roller. The metallic roller is arranged so as to satisfy ?1<?2, where an angle of the endless belt with respect to a tangent to the image carrier, on a side upstream of rotation of the endless belt to a transfer nip region where the image carrier and the endless belt are in contact is ?1, and an angle of the endless belt with respect to the tangent, on a side downstream of rotation of the endless belt to the transfer nip region is ?2.Type: GrantFiled: February 27, 2006Date of Patent: September 23, 2008Assignee: Ricoh Company, LimitedInventors: Yoshie Iwakura, Akihiro Kawasaki, Atsushi Takehara, Takafumi Miyazaki, Tomoya Adachi
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Patent number: 7418234Abstract: A discharge unit is disposed downstream of a principal transport path of a compound machine, and a shifter function is provided in this discharge unit. By shifting the paper passage position relative to a photosensitive drum when printing the front side and the paper passage position relative to the photosensitive drum when printing the back side, the region in which the surface electric potential of the photosensitive drum increases is diminished, and the region in which photographic fog is generated is made smaller. Thus, when printing the second and subsequent sheets, even when a slight amount of displacement of the transport position of the recording paper occurs, it is possible to suppress that recording paper making contact in the photographic fog region on the photosensitive drum, and defective printing can be prevented.Type: GrantFiled: April 9, 2004Date of Patent: August 26, 2008Assignee: Sharp Kabushiki KaishaInventors: Susumu Murakami, Minoru Tomiyori, Hideshi Izumi, Takahisa Narikiyo, Kuniaki Nakano, Yoshie Iwakura
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Patent number: 7415218Abstract: In an image forming apparatus that uses a charging unit to charge a photosensitive drum, forms an electrostatic latent image by carrying out image exposure according to image information, and transfers to a paper the electrostatic latent image by developing the electrostatic latent image into a visible image using a developer so that the image information is presented, an exhaust duct 33 for exhausting air that contains ozone produced within a drum unit 30, which includes a photosensitive drum 3 and a charging unit 5, and a duct 32 for taking in air, which draws in fresh air, are provided within the drum unit 30 so that ventilation of the drum unit 30 can be carried out with excellent efficiency.Type: GrantFiled: July 5, 2005Date of Patent: August 19, 2008Assignee: Sharp Kabushiki KaishaInventors: Takashi Hori, Kuniaki Nakano, Tomohiko Fujii, Yoshie Iwakura
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Patent number: 7398041Abstract: A color image forming apparatus 1 includes: a multiple number of process printing units 20, each having an photoreceptor drum 21 for bearing a developer image formed with a toner corresponding to a different color of color-separated image information; a transfer belt 31 to which a multiple number of developer images are comprised in layers; and a transfer roller 36 for transferring the developer images that have been comprised in layers on transfer belt 31, all at once, to recording paper, wherein the multiple number of process printing units 20 are arranged along transfer belt 31, and is characterized in that among the developer images to be transferred from the photoreceptor drums 21 of multiple image forming units 20 onto transfer belt 31, the toner for the developer image of the color to be transferred first is specified to produce a base-layer of the color images of information.Type: GrantFiled: September 6, 2005Date of Patent: July 8, 2008Assignee: Sharp Kabushiki KaishaInventors: Yoshie Iwakura, Susumu Murakami, Kuniaki Nakano
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Patent number: 7379694Abstract: A combined resistance R1=Vt1/I1 (MO) of a transfer belt (61) and a recording sheet obtained when a transfer current I1 (?A) passes through the transfer belt (61) and the recording sheet upon application of a first transfer bias voltage Vt1 (V) to a transfer roller (6b) from a high-voltage power source (6f) and a combined resistance R2=Vt2/I2 (MO) of the transfer belt (61) and the recording sheet obtained when a transfer current I2 (?A) passes through the transfer belt (61) and the recording sheet upon application of a second transfer bias voltage Vt2 (V) to the transfer roller (6b) from the high-voltage power source (6f), are established to have the relationship: R2/R1=7 ?(I2)?0.5 therebetween.Type: GrantFiled: March 10, 2004Date of Patent: May 27, 2008Assignee: Sharp Kabushiki KaishaInventors: Toshiki Takiguchi, Yoko Sawa, Hirokazu Yamauchi, Yoshiaki Masuda, Yoshie Iwakura, Hiroshi Ishii
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Patent number: 7369800Abstract: An image forming apparatus is constituted so as to be equipped with transfer apparatus(es) having transfer roller(s) electrostatically transferring development image(s) from photosensitive drum(s) to transfer medium/media, and so as to be provided with transfer medium guide unit disposed downstream in transfer medium transport path(s) from location(s) at which photosensitive drum(s) oppose transfer roller(s), and such that transfer medium guide location(s) of transfer medium guide means is/are variable.Type: GrantFiled: March 21, 2005Date of Patent: May 6, 2008Assignee: Sharp Kabushiki KaishaInventors: Hideshi Izumi, Susumu Murakami, Minoru Tomiyori, Tomohiko Fujii, Yoshie Iwakura
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Publication number: 20080069605Abstract: Provided is an image forming method that comprises a charging step, an exposing step, a developing step, an intermediate transfer step and a secondary transfer step, wherein the diameter R (mm) of a secondary transfer roller used in the secondary transfer step and the distance A (mm) between a nip center of the secondary transfer roller and a site where paper contacts with a secondary transfer belt at ingress side satisfy the following relation, and the charge amount Q (?C/g) of the toner going into the secondary transfer step satisfies the following relation.Type: ApplicationFiled: September 14, 2007Publication date: March 20, 2008Inventors: Kazuoki FUWA, Masayuki Hagi, Yoshihiro Mikuriya, Hideaki Yasunaga, Hiroaki Kato, Yoshitaka Sekiguchi, Yoshie Iwakura
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Patent number: 7330686Abstract: A color image forming apparatus includes: a multiple number of process printing units, each having an photoreceptor drum for supporting a developer image formed with a developer corresponding to each color of color-separated image information; a transfer belt to which the developer images formed on the photoreceptor drums are transferred; and a transfer roller for transferring the transferred developer image to recording paper, and is constructed so that the transfer belt is formed of a material which makes it possible for the transfer belt to attenuate the voltage charged thereon by 1,000 V or greater while it moves from a position where secondary transfer is performed to a position where the initial primary transfer is performed.Type: GrantFiled: September 27, 2005Date of Patent: February 12, 2008Assignee: Sharp Kabushiki KaishaInventors: Kuniaki Nakano, Yoshie Iwakura, Susumu Murakami
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Patent number: 7305207Abstract: A cleaning system includes a rotating member and a cleaning blade which is forced against a curved outer surface of the rotating member to scrape off matter to be removed (toner) which is present along the outer surface of the rotating member. The cleaning blade has greater hardness than the outer surface of the rotating member.Type: GrantFiled: February 22, 2005Date of Patent: December 4, 2007Assignee: Sharp Kabushiki KaishaInventors: Susumu Murakami, Yoshie Iwakura, Kuniaki Nakano
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Patent number: 7280788Abstract: An image forming apparatus according to the present invention is provided with a plurality of image bearing members, an intermediate transfer member, a plurality of first transfer devices, a second transfer device, and a charge amount adjustment section. The image bearing members carry images of respective colors. The intermediate transfer member is rotatably disposed at a position opposed to the image bearing members. The first transfer devices form a full-color toner image on the intermediate transfer member by transferring color toner images formed on the image bearing members to the intermediate transfer member. The second transfer device transfers the full-color toner image formed on the intermediate transfer member to a recording sheet. The charge amount adjustment section adjusts the charge amount of toner particles constituting the full-color toner image so as to reduce non-uniformity in a charge amount of toner particles of the full-color toner image on the intermediate transfer member per unit area.Type: GrantFiled: September 21, 2005Date of Patent: October 9, 2007Assignee: Sharp Kabushiki KaishaInventors: Yoshie Iwakura, Kuniaki Nakano