Patents by Inventor Daisuke Kuboshima
Daisuke Kuboshima 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: 9141007Abstract: Provided is a monolayer type photoconductor superior in sensitivity characteristics that allows reliable production by easy confirmation of the sensitivity characteristics, and an image forming device using such a monolayer type photoconductor. A monolayer type photoconductor including a base body and a single photo sensitive layer formed on the base body, the single photo sensitive layer containing a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin, wherein a maximum absorption wavelength (?max) of the photo sensitive layer is set to a value of below 850 nm and an absorbance (A850) of light at a wavelength of 850 nm per unit thickness of the photo sensitive layer is set to a value of 0.05 ?m?1 or less.Type: GrantFiled: March 13, 2008Date of Patent: September 22, 2015Assignee: Kyocera Mita CorporationInventors: Kazunari Hamasaki, Yuko Iwashita, Daisuke Kuboshima, Keiji Maruo, Shiho Kuboshima
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Patent number: 8686133Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.Type: GrantFiled: July 11, 2012Date of Patent: April 1, 2014Assignee: Kyocera Document Solutions Inc.Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
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Patent number: 8679710Abstract: The present invention provides an electrophotographic photoreceptor comprising a photosensitive layer that contains at least a charge generating agent, a hole transport agent and a prede mulas (A) and (B). The electrophotographic photoreceptor prevents image defect termined additive. The hole transport agent satisfies the following for from occurring and can meet the demand for higher speed image forming apparatuses, by reducing the adhesion of paper dust and preventing the occurrence of cracks. ? ? M < 1.2 × 10 - 8 ( A ) ? ? > 5.Type: GrantFiled: December 22, 2005Date of Patent: March 25, 2014Assignee: Kyocera Document Solutions Inc.Inventors: Daisuke Kuboshima, Eiichi Miyamoto, Kazunari Hamasaki, Norio Nakai, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
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Publication number: 20120296082Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor the oxo-titanylphthalocyanine crystal has predetermined optical characteristics and thermal properties and is produced by a production method including the following steps (a) to (d): (a) a step of dissolving a crude oxo-titanylphthalocyanine crystal in an acid to obtain an oxo-titanylphthalocyanine solution; (b) a step of adding the oxo-titanylphthalocyanine solution dropwise in a poor solvent to obtain a wet cake; (c) a step of washing the wet cake with an alcohol having 1 to 4 carbon atoms; and (d) a step of stirring the washed wet cake under heating in a nonaqueous solvent to obtain an oxo-titanylphthalocyaType: ApplicationFiled: July 11, 2012Publication date: November 22, 2012Inventors: Daisuke KUBOSHIMA, Jun AZUMA, Yoshio INAGAKI, Junichiro OTSUBO, Keiji MARUO
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Patent number: 8242261Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.Type: GrantFiled: October 1, 2010Date of Patent: August 14, 2012Assignee: Kyocera Mita CorporationInventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
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Publication number: 20110046392Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.Type: ApplicationFiled: October 1, 2010Publication date: February 24, 2011Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
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Patent number: 7838191Abstract: The present invention provides a monolayer type electrophotographic photoconductor which can effectively suppress the generation of an exposure memory and exhibits high sensitivity and an image forming apparatus using the monolayer type electrophotographic photoconductor. In an electrophotographic photoconductor which has a monolayer type photoconductive layer including at least a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin on a substrate, the charge generating agent contains oxo-titanyl phthalocyanine crystal, the electron transfer agent has a reduction potential thereof set to a value which falls within a range from ?0.97 to ?0.83 V, and the reflection absorbance (A/?) of the photoconductive layer with respect to light having a wavelength of 700 nm, a film thickness (d/m) of the photoconductive layer, and the concentration (C/weight %) of the oxo-titanyl phthalocyanine crystal of the photoconductive layer (100 weight %) satisfy a following formula (1).Type: GrantFiled: March 12, 2007Date of Patent: November 23, 2010Assignee: Kyocera Mita CorporationInventors: Daisuke Kuboshima, Kazunari Hamasaki, Yuko Iwashita
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Patent number: 7754402Abstract: The present invention provides an electrophotographic photoconductive member comprising a substrate, and a photoconductive layer containing a hole transferring material, a charge generating material and a binder resin, wherein a value (IV/OV value) in which the inorganic value is divided by the organic value of the binder resin is 0.Type: GrantFiled: December 19, 2007Date of Patent: July 13, 2010Assignee: Kyocera Mita CorporationInventors: Kazunari Hamasaki, Shiho Kuboshima, Daisuke Kuboshima, Yuko Iwashita
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Patent number: 7700251Abstract: An electrophotographic photoconductor having an excellent crack resistance and wear resistance as well as excellent sensitivity characteristics, while keeping good image characteristics of the photoconductor is provided. In addition, an image-forming apparatus equipped with such an electrophotographic photoconductor is also provided. The electrophotographic photoconductor includes a photosensitive layer containing at least a charge-generating agent, a hole-transfer agent, and a binder resin on a conductive substrate.Type: GrantFiled: October 18, 2006Date of Patent: April 20, 2010Assignee: Kyocera Mita CorporationInventors: Norio Nakai, Kazunari Hamasaki, Daisuke Kuboshima, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
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Publication number: 20080305418Abstract: Provided is a monolayer type photoconductor superior in sensitivity characteristics that allows reliable production by easy confirmation of the sensitivity characteristics, and an image forming device using such a monolayer type photoconductor. A monolayer type photoconductor including a base body and a single photo sensitive layer formed on the base body, the single photo sensitive layer containing a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin, wherein a maximum absorption wavelength (?max) of the photo sensitive layer is set to a value of below 850 nm and an absorbance (A850) of light at a wavelength of 850 nm per unit thickness of the photo sensitive layer is set to a value of 0.05 ?m?1 or less.Type: ApplicationFiled: March 13, 2008Publication date: December 11, 2008Applicant: Kyocera Mita CorporationInventors: Kazunari Hamasaki, Yuko Iwashita, Daisuke Kuboshima, Keiji Maruo, Shiho Kuboshima
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Publication number: 20080286673Abstract: The present invention provides a single layer type electrophotographic photoconductor which exhibits the small number of generated black spots in a formed image and exhibits the excellent sensitivity characteristic even when the photoconductor is used for a long time or a photoconductor drum is rotated at a high speed and an image display device which includes the single layer type electrophotographic photoconductor. In the single layer type electrophotographic photoconductor which includes a photoconductive layer containing a binding resin, a hole transporting agent and an charge generating agent, the photoconductor contains a water-repellant polycarbonate resin as the binding resin, and a contact angle of pure water (measured temperature: 25° C.) with respect to the photoconductive layer is set to 100° or more.Type: ApplicationFiled: July 18, 2008Publication date: November 20, 2008Inventors: Daisuke Kuboshima, Kazunari Hamasaki, Norio Nakai
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Patent number: 7416825Abstract: The present invention provides a single layer type electrophotographic photoconductor which exhibits the small number of generated black spots in a formed image and exhibits the excellent sensitivity characteristic even when the photoconductor is used for a long time or a photoconductor drum is rotated at a high speed and an image display device which includes the single layer type electrophotographic photoconductor. In the single layer type electrophotographic photoconductor which includes a photoconductive layer containing a binding resin, a hole transporting agent and an charge generating agent, the photoconductor contains a water-repellant polycarbonate resin as the binding resin, and a contact angle of pure water (measured temperature: 25° C.) with respect to the photoconductive layer is set to 100° or more.Type: GrantFiled: January 4, 2006Date of Patent: August 26, 2008Assignee: Kyocera Mita CorporationInventors: Daisuke Kuboshima, Kazunari Hamasaki, Norio Nakai
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Publication number: 20080153020Abstract: The present invention provides an electrophotographic photoconductive member comprising a substrate, and a photoconductive layer containing a hole transferring material, a charge generating material and a binder resin, wherein a value (IV/OV value) in which the inorganic value is divided by the organic value of the binder resin is 0.Type: ApplicationFiled: December 19, 2007Publication date: June 26, 2008Applicant: Kyocera Mita CorporationInventors: Kazunari Hamasaki, Shiho Kuboshima, Daisuke Kuboshima, Yuko Iwashita
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Publication number: 20080026310Abstract: The invention provides an oxo-titanylphthalocyanine crystal which is stable, is superior in dispersibility in a photoreceptive layer and efficiently contributes to improvements in sensitivity and charge retention rate of an electrophotographic photoreceptor when it is used as a charge generating agent, a method for producing the oxo-titanylphthalocyanine crystal, and an electrophotographic photoreceptor.Type: ApplicationFiled: July 10, 2007Publication date: January 31, 2008Inventors: Daisuke Kuboshima, Jun Azuma, Yoshio Inagaki, Junichiro Otsubo, Keiji Maruo
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Publication number: 20070218379Abstract: The present invention provides a monolayer type electrophotographic photoconductor which can effectively suppress the generation of an exposure memory and exhibits high sensitivity and an image forming apparatus using the monolayer type electrophotographic photoconductor. In an electrophotographic photoconductor which has a monolayer type photoconductive layer including at least a charge generating agent, a hole transfer agent, an electron transfer agent and a binding resin on a substrate, the charge generating agent contains oxo-titanyl phthalocyanine crystal, the electron transfer agent has a reduction potential thereof set to a value which falls within a range from ?0.97 to ?0.83 V, and the reflection absorbance (A/?) of the photoconductive layer with respect to light having a wavelength of 700 nm, a film thickness (d/m) of the photoconductive layer, and the concentration (C/weight %) of the oxo-titanyl phthalocyanine crystal of the photoconductive layer (100 weight %) satisfy a following formula (1).Type: ApplicationFiled: March 12, 2007Publication date: September 20, 2007Inventors: Daisuke Kuboshima, Kazunari Hamasaki, Yuko Iwashita
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Publication number: 20070111118Abstract: An electrophotographic photoconductor having an excellent crack resistance and wear resistance as well as excellent sensitivity characteristics, while keeping good image characteristics of the photoconductor is provided. In addition, an image-forming apparatus equipped with such an electrophotographic photoconductor is also provided. The electrophotographic photoconductor includes a photosensitive layer containing at least a charge-generating agent, a hole-transfer agent, and a binder resin on a conductive substrate.Type: ApplicationFiled: October 18, 2006Publication date: May 17, 2007Inventors: Norio Nakai, Kazunari Hamasaki, Daisuke Kuboshima, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
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Patent number: 7101647Abstract: The present invention provides an electrophotosensitive material which realizes uniform dispersion of phthalocyanines in a photosensitive layer and has high sensitivity to a digital light source, and also excellent in charge stability under the high temperature atmosphere, weatherability and NOx resistance.Type: GrantFiled: September 23, 2003Date of Patent: September 5, 2006Assignee: Kyocera Mita CorporationInventors: Jun Azuma, Kazunari Hamasaki, Daisuke Kuboshima, Hisakazu Honma
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Publication number: 20060160005Abstract: The present invention provides a single layer type electrophotographic photoconductor which exhibits the small number of generated black spots in a formed image and exhibits the excellent sensitivity characteristic even when the photoconductor is used for a long time or a photoconductor drum is rotated at a high speed and an image display device which includes the single layer type electrophotographic photoconductor. In the single layer type electrophotographic photoconductor which includes a photoconductive layer containing a binding resin, a hole transporting agent and an charge generating agent, the photoconductor contains a water-repellant polycarbonate resin as the binding resin, and a contact angle of pure water (measured temperature: 25° C.) with respect to the photoconductive layer is set to 100° or more.Type: ApplicationFiled: January 4, 2006Publication date: July 20, 2006Inventors: Daisuke Kuboshima, Kazunari Hamasaki, Norio Nakai
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Publication number: 20060141377Abstract: The present invention provides an electrophotographic photoreceptor comprising a photosensitive layer that contains at least a charge generating agent, a hole transport agent and a predetermined additive. The hole transport agent satisfies the following formulas (A) and (B). The electrophotographic photoreceptor prevents image defect from occurring and can meet the demand for higher speed image forming apparatuses, by reducing the adhesion of paper dust and preventing the occurrence of cracks. ? ? ? M < 1.2 × 10 - 8 ( A ) ? ? ? > 5.Type: ApplicationFiled: December 22, 2005Publication date: June 29, 2006Inventors: Daisuke Kuboshima, Eiichi Miyamoto, Kazunari Hamasaki, Norio Nakai, Yoshio Inagaki, Hideki Okada, Tetsuya Ichiguchi, Keiji Maruo
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Titanyl phthalocyanine crystal and production method of the same, and electrophotosensitive material
Patent number: 7057034Abstract: The present invention relates to a novel titanyl phthalocyanine crystal which can prepare a coating solution having excellent storage stability because it satisfies both of the following two characteristics (a) and (b), a method of producing the same, an electrophotosensitive material using the above crystal as an electric charge generating material. (a) The crystal has a maximum peak at a Bragg angle 2?±0.2°=27.2° and has no peak at 7.4° in a CuK? characteristic X-ray diffraction spectrum. (b) The crystal does not have a peak of a change in temperature within a range from 50 to 400° C. except for a peak associated with evaporation of adsorbed water in differential scanning calorimetry.Type: GrantFiled: August 27, 2003Date of Patent: June 6, 2006Assignee: Kyocera Mita CorporationInventors: Kazunari Hamasaki, Daisuke Kuboshima, Hisakazu Honma, Jun Azuma, Eiichi Miyamoto