Patents by Inventor Takatsugu Obata
Takatsugu Obata 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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Publication number: 20240140918Abstract: A compound represented by formula (1) below, useful for treating cancer. In the formula, R1 and R3-R8 each independently represents a hydrogen atom or an alkyl group, R2 represents a hydrogen atom or a group represented by —ORa, R9 represents a group represented by —C(O)NRcRf, Ra, Re, and Rf each independently represents a hydrogen atom, an arylalkyl group that may have a substituent, or a heteroarylalkyl group.Type: ApplicationFiled: January 28, 2022Publication date: May 2, 2024Inventors: Isamu SHIINA, Motoyuki SHIMONAKA, Takatsugu MURATA, Yuuki OBATA, Toshirou NISHIDA, Koji OKAMOTO
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Patent number: 8546049Abstract: An electrophotographic photoconductor comprising a charge generation layer containing a charge generation material and a charge transfer layer containing a charge transfer material laminating in this order on a conductive support with an undercoat layer interposed between the charge generation layer and the conductive support, or comprising a monolayer type photosensitive layer containing a charge generation material and a charge transport material being formed on a conductive support with an undercoat layer interposed between the monolayer type photosensitive layer and the conductive support, wherein the charge transport layer or the monolayer type photosensitive layer contains, as a charge transfer material, a bisamine compound represented by the following general formula (I):Type: GrantFiled: December 14, 2011Date of Patent: October 1, 2013Assignee: Sharp Kabushiki KaishaInventors: Akiko Kihara, Akihiro Kondoh, Takatsugu Obata
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Patent number: 8354211Abstract: An electrophotographic photoreceptor comprising a layered-type photosensitive layer in which a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material are stacked, formed on a conductive supporting member made of a conductive material, wherein the electrophotographic photoreceptor has high sensitive characteristics to a semiconductor laser beam having a wavelength ranging from 380 to 500 nm; the charge transporting layer of the layered-type photosensitive layer contains as the charge transporting material, a triarylamine dimer compound represented by the general formula (1): wherein Ar1 and Ar2 may be the same or different, and represent an unsubstituted or substituted arylene group or heterocyclic derivative bivalent group, Ar3 and Ar4 may be the same or different, and represent an unsubstituted or substituted aryl group or heterocyclic group, R1 and R2 may be the same or different, and represent an alkyl group, m and n repType: GrantFiled: December 5, 2008Date of Patent: January 15, 2013Assignee: Sharp Kabushiki KaishaInventors: Akiko Kihara, Kotaro Fukushima, Takatsugu Obata, Akihiro Kondoh
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Patent number: 8206881Abstract: There provides an electrophotographic photoreceptor using a novel amine compound which has an excellent effect of ozone resistance and can be used for providing an electrophotographic photoreceptor having no adverse effect on other characteristics, and an image forming apparatus including the photoreceptor. The aim is attained by an electrophotographic photoreceptor formed by stacking a single layer type photosensitive layer containing a charge generating material and a charge transporting material, or a layered photosensitive layer, in which a charge generation layer containing a charge generating material and a charge transporting layer containing a charge transporting material are stacked in this order, on a conductive substrate made of a conductive material, wherein the single layer type photosensitive layer or the charge transporting layer of the layered photosensitive layer contains a specific amine compound.Type: GrantFiled: November 7, 2008Date of Patent: June 26, 2012Assignee: Sharp Kabushiki KaishaInventors: Takatsugu Obata, Akihiro Kondoh
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Publication number: 20120156600Abstract: An electrophotographic photoconductor comprising a charge generation layer containing a charge generation material and a charge transfer layer containing a charge transfer material laminating in this order on a conductive support with an undercoat layer interposed between the charge generation layer and the conductive support, or comprising a monolayer type photosensitive layer containing a charge generation material and a charge transport material being formed on a conductive support with an undercoat layer interposed between the monolayer type photosensitive layer and the conductive support, wherein the charge transport layer or the monolayer type photosensitive layer contains, as a charge transfer material, a bisamine compound represented by the following general formula (I):Type: ApplicationFiled: December 14, 2011Publication date: June 21, 2012Inventors: Akiko Kihara, Akihiro Kondoh, Takatsugu Obata
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Publication number: 20120156599Abstract: An electrophotographic photoconductor, comprising: a conductive support; and a photosensitive layer provided on the conductive support and containing a charge generation material and a charge transport material, the photosensitive layer containing, as the charge transport material, a compound represented by the following general formula (I): wherein Ar1 represents an optionally substituted arylene or bivalent heterocyclic group; Ar2s, which may be the same or different, each represent a hydrogen atom or an optionally substituted alkyl, aralkyl, aryl or monovalent heterocyclic group; R1 represents an optionally substituted alkyl group; R2s each represent a hydrogen atom or an optionally substituted alkyl group; R3 and R4s, which may be the same or different, each represent a hydrogen atom or an optionally substituted alkyl or alkoxy group; and n is 0 or 1.Type: ApplicationFiled: December 5, 2011Publication date: June 21, 2012Inventors: Takatsugu Obata, Akihiro Kondoh
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Patent number: 8003287Abstract: The present invention provides an electrophotographic photoconductor comprising an electroconductive substrate and a photosensitive layer provided on the electroconductive substrate, wherein the photosensitive layer comprises a charge-generating material and a charge-transporting material, the charge-transporting material comprising a compound represented by the general formula (1): wherein Ar1 and Ar2 each independently represent an optionally-substituted arylene or bivalent heterocyclic group; Ar3 and Ar4 each independently represent a hydrogen atom, or an optionally-substituted aryl or monovalent heterocyclic group, but are not simultaneously hydrogen atoms; or Ar3 and Ar4 may be taken together to form an optionally-substituted bivalent cyclic hydrocarbon or heterocyclic group; and n is 0 or 1.Type: GrantFiled: December 17, 2007Date of Patent: August 23, 2011Assignee: Sharp Kabushiki KaishaInventors: Takatsugu Obata, Akihiro Kondoh
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Patent number: 7985519Abstract: In an electrophotographic photoreceptor including a conductive substrate and a single layer type photosensitive layer, the aromatic polycarbonate is contained to a single layer type photosensitive layer, which aromatic polycarbonate includes a constituent unit represented by the following general formula (1) derived from a compound having a basic asymmetric bishydroxy enamine skeleton represented by the general formula: Accordingly, the electrophotographic photoreceptor is obtained which is excellent in charge transportability, mechanical strength, electric property, durability, etc. and can form good images for a long time.Type: GrantFiled: January 29, 2008Date of Patent: July 26, 2011Assignee: Sharp Kabushiki KaishaInventors: Akiko Kihara, Akihiro Kondoh, Hiroshi Sugimura, Takatsugu Obata
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Patent number: 7977020Abstract: An electrophotographic photoreceptor comprising laminating a monolayer type photosensitive layer containing a charge generation material and a charge transport material or a laminate type photosensitive layer obtained by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material in this order, on a conductive support, wherein the charge transport layer of the monolayer type photosensitive layer or laminate type photosensitive layer contains an enamine compound represented by the following formula (1).Type: GrantFiled: April 24, 2008Date of Patent: July 12, 2011Assignee: Sharp Kabushiki KaishaInventors: Takatsugu Obata, Akihiro Kondoh
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Patent number: 7803507Abstract: An electrophotographic photoreceptor of high durability capable of providing stable excellent electrical characteristics over a prolonged period of time, which electrophotographic photoreceptor excels in mechanical strength. A photosensitive layer (14) of an electrophotographic photoreceptor (1) includes a polyarylate resin having structural units, for example, those of formula (1) and an enamine compound represented by, for example, formula (2) The variables R1, R2, R3, R4, R7˜R10, X1, Ar1, Ar2, Ar3, Ar4, Ar5, R11, R12, R13, R14, a, m, and n are as defined in the specification. By virtue of these, the electrophotographic photoreceptor (1) of excellent mechanical strength and favorable electrical characteristics can be realized.Type: GrantFiled: February 6, 2004Date of Patent: September 28, 2010Assignee: Sharp Kabushiki KaishaInventors: Tatsuhiro Morita, Tomoko Kanazawa, Akihiro Kondoh, Yohichi Takesawa, Takatsugu Obata, Shinya Mimura, Hiroshi Sugimura
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Patent number: 7794907Abstract: A hydrazone compound capable of realizing an electrophotographic photoreceptor having good electric properties such as good sensitivity and light responsibility, good electric and mechanical durability and good environment stability, is provided. The hydrazone compound is represented by the following general formula (1). The compound is contained in the charge transporting layer of the electrophotographic photoreceptor.Type: GrantFiled: September 7, 2005Date of Patent: September 14, 2010Assignee: Sharp Kabushiki KaishaInventors: Akihiro Kondoh, Takatsugu Obata
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Patent number: 7781137Abstract: A method for producing a high-quality and low-cost laminate type electrophotographic photoreceptor having a coating film of uniform thickness with high efficiency is provided. In the electrophotographic photoreceptor having a laminated structure composed at least of two layers: a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance, the charge generating layer is formed by applying a coating solution for forming the charge generating layer onto the conductive support by an ink-jet coating method, and the charge transporting layer is formed by applying a coating solution for forming the charge transporting layer onto the charge generating layer by a roll coating method.Type: GrantFiled: April 26, 2005Date of Patent: August 24, 2010Assignee: Sharp Kabushiki KaishaInventors: Mikio Kakui, Takatsugu Obata, Masanori Kinomoto
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Patent number: 7754403Abstract: An organic photoconductive material which is useful as a raw material compound for a variety of functional materials and makes it possible to implement an electrophotoconductor which is excellent in terms of the charge transporting performance, excellent in terms of dissolution in solvents and compatibility with resins, and excellent in terms of both the electrical properties and durability is provided. An example is an asymmetric bishydroxy compound which can be represented by the following structural formula (1aa). This compound is contained in a charge transforming layer 4 or a surface protective layer 5 of an electrophotoconductor 18. As a result, an electrophotoconductor 18 which is excellent in terms of the electrical properties and durability and can stably form high quality images without image defects such as black dots can be implemented.Type: GrantFiled: February 21, 2007Date of Patent: July 13, 2010Assignee: Sharp Kabushiki KaishaInventors: Akihiro Kondoh, Hiroshi Sugimura, Takatsugu Obata
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Patent number: 7727693Abstract: An object of the invention is to provide an electrophotographic photoreceptor showing high responsivity even under a low temperature and low humidity circumstance and capable of compatibilize the decrease of the size and the increase in the image forming speed of an electrophotographic apparatus. In a photosensitive layer of an electrophotographic photoreceptor, oxotitanium phthalocyanine having a crystal form showing a diffraction peak at a Bragg angle 2? (error: 2?±0.2°) of 27.2° in an X-ray diffraction spectrum is contained as a charge generating substance, and an enamine compound represented by the general formula for example, the structural formula (1-1) is contained as a charge transporting substance. Accordingly, the electrophotographic photoreceptor showing high responsivity even under a low temperature and low humidity circumstance is realized.Type: GrantFiled: April 16, 2004Date of Patent: June 1, 2010Assignee: Sharp Kabushiki KaishaInventors: Kazuya Ishida, Akihiro Kondoh, Takatsugu Obata
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Publication number: 20100028047Abstract: The present invention provides an image forming apparatus provided with the highly sensitive electrophotographic photoreceptor comprising an enamine compound as a charge transport substance having a specific enamine structure; and provided with the semiconductor laser oscillating the laser beam with the oscillation wavelengths of from 390 nm to 500 nm inclusive in order to form an image having a high resolution for a long period of time.Type: ApplicationFiled: July 31, 2009Publication date: February 4, 2010Inventors: Akihiro Kondoh, Takatsugu Obata
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Publication number: 20090305155Abstract: A electrophotographic photoreceptor comprising a monolayered photosensitive layer containing a charge generation material and a charge transport material or a multilayered photosensitive layer obtained by laying a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material in this order or in reverse order, on a conductive support, wherein the monolayered photosensitive layer or the charge transport layer of the multilayered photosensitive layer contains, as the charge transport material, an enamine compound represented by the formula (I): wherein Ar1 and Ar2, which may be the same or different, respectively represent an aryl group which may have a substituent or a monovalent heterocyclic residue which may have a substituent; R1 and R2, which may be the same or different, respectively represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent or an alkoxy group which may have a substituent; and R3 represeType: ApplicationFiled: June 4, 2009Publication date: December 10, 2009Inventors: Takatsugu OBATA, Akihiro KONDOH
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Patent number: 7625681Abstract: There is provided an organic photoconductive material that can realize an electrophotographic photoreceptor which is not only excellent in charge transporting ability but also excellent in solubility in a solvent and compatibility with a resin and moreover, which is excellent in both electric properties and durability, and the organic photoconductive material that is useful also as a raw material compound for various types of functional materials. An asymmetric bis-hydroxyenamine compound represented by the following structural formula (1aa) is provided. The compound is allowed to be contained in a charge transporting layer or a surface protective layer of an electrophotographic photoreceptor. This leads realization of the electrophotographic photoreceptor which is excellent in electric properties and durability and can stably form an image of high quality being free of an image defect such as a black spot.Type: GrantFiled: May 31, 2006Date of Patent: December 1, 2009Assignee: Sharp Kabushiki KaishaInventors: Akihiro Kondoh, Hiroshi Sugimura, Takatsugu Obata
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Patent number: 7615326Abstract: A charge transporting substance having three stilbene structures or butadiene structures in a molecule, represented by the following general formula is used as an organic photoconductive material. An electrophotographic photoconductor is prepared by causing a photosensitive layer which is disposed on a conductive support, to contain the organic photoconductive material in order to dispose the photoconductor to an image forming apparatus.Type: GrantFiled: June 1, 2007Date of Patent: November 10, 2009Assignee: Sharp Kabushiki KaishaInventors: Takatsugu Obata, Akihiro Kondoh
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Patent number: 7588871Abstract: An electrophotographic photoreceptor having excellent electric characteristics such as sensitivity characteristic and light responsiveness with an excellent life duration of abrasion resistance so that no flaw and density unevenness are generated on to-be-formed images for a long period of time, is provided. In an electrophotographic photoreceptor (1), an enamine compound represented by the following general formula (1), for example, an enamine compound represented by the following structural formula (1-1) is contained in a charge transporting layer (6), and a creep value (CIT) in a case where a maximum indentation load of 30 mN is put on a surface for 5 seconds under circumstances of temperature of 25° C. and relative humidity of 50%, is set to 2.70% or more and 5.00% or less, and a plastic deformation hardness value (Hplast) of the surface is set to 220 N/mm2 or more and 275 N/mm2 or less.Type: GrantFiled: October 8, 2004Date of Patent: September 15, 2009Assignee: Sharp Kabushiki KaishaInventors: Akiko Kihara, Kotaro Fukushima, Takatsugu Obata
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Patent number: 7563548Abstract: An amine compound represented by the general formula (1), which is incorporated as a charge-transporting substance to a charge-transporting layer of an electrophotographic photoreceptor: (in which Ar1, Ar2 and Ar3 each represents an optionally-substituted aryl group, or an optionally-substituted monovalent heterocyclic ring residue. Ar4 represents an optionally-substituted arylene group, or an optionally-substituted bivalent heterocyclic ring residue. R1 represents an optionally-substituted alkyl group, an optionally-substituted aryl group, an optionally-substituted monovalent heterocyclic ring residue, or an optionally-substituted aralkyl group. R2 and R3 each represents a hydrogen atom, an optionally-substituted alkyl group, an optionally-substituted aryl group, an optionally-substituted monovalent heterocyclic ring residue, or an optionally-substituted aralkyl group. n represents an integer of 1 or 2.Type: GrantFiled: November 30, 2004Date of Patent: July 21, 2009Assignee: Sharp Kabushiki KaishaInventors: Akihiro Kondoh, Takatsugu Obata