Patents by Inventor Masaki Uchiyama
Masaki Uchiyama 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).
-
Publication number: 20070222843Abstract: A printer includes a recording head having a nozzle that ejects ink and a suction pump that draws the ink through the nozzle. A valve unit and a filter are arranged in a passage that supplies the ink to the recording head. A controller of the printer operates the suction pump to perform suction/suspension in which suction of the ink from the passage through the nozzle and suspension of the suction are alternately repeated with the valve unit maintained in a closed state, thus promoting joining of bubbles on the filter. The controller then operates to open the valve unit to drain the joint bubbles from the filter, together with the ink, using negative pressure accumulated in the passage.Type: ApplicationFiled: February 28, 2007Publication date: September 27, 2007Applicant: Seiko Epson CorporationInventors: Masaki Uchiyama, Takeo Seino
-
Patent number: 5863697Abstract: A toner for developing an electrostatic image has toner particles containing a binder resin and a colorant. The toner particle has at least a core composed of a low-temperature softening substance, an inner layer enclosing the core, and an outer layer enclosing the core and the inner layer. The core, the inner layer, and the outer layer are constituted respectively of a material which is discriminable by staining with triruthenium tetroxide and triosmium tetroxide.Type: GrantFiled: April 2, 1998Date of Patent: January 26, 1999Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Tatsuya Nakamura, Shinya Yachi
-
Patent number: 5863695Abstract: Disclosed is a toner for developing an electrostatic image. The toner comprises a binder resin and a wax, and the value of weight average molecular weight/number average molecular weight (Mw/Mn) of the wax is not more than 1.5.Type: GrantFiled: November 22, 1996Date of Patent: January 26, 1999Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Shinji Doi, Masaki Uchiyama
-
Patent number: 5849453Abstract: An image forming method has the steps of forming a toner image by developing through a developing means a latent image formed on a latent image bearing member; transferring the toner image formed, from the latent image bearing member to a transfer medium through a transfer means to which a bias is applied; cleaning the latent image bearing member from which the toner image has been transferred to the transfer medium, to recover and collect the toner remaining on the latent image bearing member; and feeding the toner recovered and collected, to the developing means for reuse in the developing step. The toner has a binder resin and at least one of a magnetic powder and a colorant. The toner has a weight average particle diameter (D.sub.4) of from 4 .mu.m to 11 .mu.m; a coefficient A of variation of number-base distribution, of not more than 40, which is a coefficient represented by the formula:A=S.sub.n /D.sub.1 .times.100wherein S.sub.n represents a standard deviation of number-base distribution, and D.sub.Type: GrantFiled: June 8, 1993Date of Patent: December 15, 1998Assignee: Canon Kabushiki KaishaInventors: Yushi Mikuriya, Masaki Uchiyama, Yasutaka Akashi
-
Patent number: 5795694Abstract: A toner for developing an electrostatic image has toner particles containing a binder resin and a colorant. The toner particle has at least a core composed of a low-temperature softening substance, an inner layer enclosing the core, and an outer layer enclosing the core and the inner layer. The core, the inner layer, and the outer layer are constituted respectively of a material which is discriminable by staining with triruthenium tetroxide and triosmium tetroxide.Type: GrantFiled: May 16, 1996Date of Patent: August 18, 1998Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Tatsuya Nakamura, Shinya Yachi
-
Patent number: 5641600Abstract: A magnetic toner composed of a binder resin and magnetic fine particles, wherein the magnetic fine particles are coated with an iron-zinc oxide on their surfaces and the magnetic fine particles have a saturation magnetization (.sigma.s) of 50 Am.sup.2 /kg or above under a magnetic field of 79.58 kA/m (1K oersted) where the product of residual magnetization (.sigma.r, Am.sup.2 /kg) and coercive force (Hc, kA/m), .sigma.r.times.Hc, is in the range between 60 and 250 (kA.sup.2 m/kg).Type: GrantFiled: July 31, 1995Date of Patent: June 24, 1997Assignee: Canon Kabushiki KaishaInventors: Takaaki Kotaki, Masaki Uchiyama, Yasutaka Akashi, Makoto Unno, Yushi Mikuriya, Tadashi Dojyo
-
Patent number: 5629122Abstract: Disclosed is a toner for developing an electrostatic image. The toner comprises a binder resin and a wax, and the value of weight average molecular weight/number average molecular weight (Mw/Mn) of the wax is not more than 1.5.Type: GrantFiled: June 6, 1995Date of Patent: May 13, 1997Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Shinji Doi, Masaki Uchiyama
-
Patent number: 5504272Abstract: An image forming method in which a toner-carrying member for carrying a specific magnetic toner is placed adjacent a latent image-bearing member for carrying an electrostatic latent image so as to form a developing region of a predetermined gap size. The magnetic toner on the toner-carrying member forms a toner layer of a regulated thickness smaller than the above-mentioned gap. An asymmetric bias is applied to the magnetic toner so as to cause the magnetic toner from the toner-carrying member to be conveyed to the latent image-bearing member thereby to develop the electrostatic latent image.Type: GrantFiled: May 20, 1994Date of Patent: April 2, 1996Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Hirohide Tanikawa, Yasutaka Akashi, Masaaki Taya, Makoto Unno
-
Patent number: 5500318Abstract: A toner for developing an electrostatic image is constituted by a binder resin and a colorant The binder resin is characterized by containing at least 20 wt. % of an extraction residue after 6 hours of extraction and below 20 wt. % of an extraction residue after 72 hours of extraction respectively by Soxhlet extraction with tetrahydrofuran. The toner shows a dynamic modulus and a loss modulus, respectively at 200.degree. C. and 0.1 Hz, which are substantially unchanging with time. The properties provide the toner with a harmonization of anti-offset characteristic and fixability as well as stable viscoelasticity under heating.Type: GrantFiled: June 27, 1994Date of Patent: March 19, 1996Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Masaki Uchiyama, Yoshinobu Joh, Yasutaka Akashi, Masaaki Taya, Makoto Unno
-
Patent number: 5480755Abstract: A magnetic toner has magnetic resin particles containing at least a binder resin, a charge control agent and a magnetic powder. The surface-modified fine silica powder being a fine silica powder has been treated with a hydrophobicizing agent. The fine silica powder has a specific surface area of not less than 180 m.sup.2 /g, a hydrophobicity of from 60% to 95% and a bulk density of from 35 g/lit. to 49 g/lit.Type: GrantFiled: August 19, 1994Date of Patent: January 2, 1996Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Yoshinobu Jo, Yasutaka Akashi, Masaaki Taya, Makoto Unno
-
Patent number: 5415967Abstract: A process for producing a toner comprises the steps of mixing toner particles having a weight average particle diameter of from 2 to 15 .mu.m, with an external additive to prepare a toner, and passing the resulting toner through a sieve. The sieve has a wire cloth of twill weave that satisfies the following condition:0.052.ltoreq.d mm .ltoreq.0.208100.ltoreq.W .mu.m .ltoreq.1807.3.times.10.sup.-4 .ltoreq.d mm / W .mu.m.ltoreq.9.1.times.10.sup.-4wherein d represents average diameter of the wire used in the sieve, and W represents an aperture size of the sieve.Type: GrantFiled: April 13, 1993Date of Patent: May 16, 1995Assignee: Canon Kabushiki KaishaInventors: Kiichiro Sakashita, Masaki Uchiyama, Masami Fujimoto, Kiyoshi Mizoe
-
Patent number: 5348829Abstract: A monocomponent-type developer for developing electrostatic images, includes a magnetic toner containing at least a binder resin and magnetic powder, and 0.5-10 wt. % (based on the magnetic toner) of inorganic fine powder having a length-average particle size of 0.1-5 .mu.m. The developer has a number-basis particle size distribution such that particles of 4 .mu.m or smaller are contained at 5-18% by number and particles of 4-10 .mu.m are contained at at least 60% by number. The developer has a volume basis particle size distribution such that particles of 12.7 .mu.m or larger are contained at at most 10% by volume. The developer has a weight-average particle size of 7-11 .mu.m. The developer is particularly useful for development under application of a DC-superposed asymmetric AC bias electric field including a development-side voltage component with a larger magnitude and a shorter duration than a reverse development-side voltage component.Type: GrantFiled: November 6, 1992Date of Patent: September 20, 1994Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Yasutaka Akashi, Masaaki Taya, Makoto Unno
-
Patent number: 5338894Abstract: An image forming method in which a toner-carrying member for carrying a specific magnetic toner is placed adjacent a latent image-bearing member for carrying an electrostatic latent image so as to form a developing region of a predetermined gap size. The magnetic toner on the toner-carrying member forms a toner layer of a regulated thickness smaller than the above-mentioned gap. An asymmetric bias is applied to the magnetic toner so as to cause the magnetic toner from the toner-carrying member to be conveyed to the latent image-bearing member thereby to develop the electrostatic latent image.Type: GrantFiled: September 20, 1991Date of Patent: August 16, 1994Assignee: Canon Kabushiki KaishaInventors: Masaki Uchiyama, Hirohide Tanikawa, Yasutaka Akashi, Masaaki Taya, Makoto Unno
-
Patent number: 5330871Abstract: A toner for developing an electrostatic image is constituted by a binder resin and a colorant. The binder resin is characterized by containing at least 20 wt. % of an extraction residue after 6 hours of extraction and below 20 wt. % of an extraction residue after 72 hours of extraction respectively by Soxhlet extraction with tetrahydrofuran. The toner shows a dynamic modulus and a loss modulus, respectively at 200.degree. C. and 0.1 Hz, which are substantially unchanging with time. The properties provide the toner with a harmonization of anti-offset characteristic and fixability as well as stable viscoelasticity under heating.Type: GrantFiled: November 26, 1991Date of Patent: July 19, 1994Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Masaki Uchiyama, Yoshinobu Joh, Yasutaka Akashi, Masaaki Taya, Makoto Unno
-
Patent number: 5296326Abstract: A magnetic toner for electrophotography having stable triboelectric chargeability under various environmental conditions may be provided by using magnetic iron oxide particles having a moderately high surface Feo content, specified by the following conditions: (a) a dissolved Fe (II) content in dissolved total iron of 14-33.3 wt. % at a dissolved total iron percentage of 5.+-.1 wt. %, (b) a dissolved Fe (II) content in dissolved total iron of 17-33.3 wt. % at a dissolved total iron percentage of 10.+-.1 wt. %, and (c) a dissolved Fe (II) content in dissolved total iron of 18-33.3 wt. % at a dissolved total iron percentage of 15.+-.1 wt.Type: GrantFiled: December 21, 1992Date of Patent: March 22, 1994Assignee: Canon Kabushiki KaishaInventors: Masaaki Taya, Hirohide Tanikawa, Yasutaka Akashi, Makoto Unno, Masaki Uchiyama, Kiichiro Sakashita
-
Patent number: 5268248Abstract: A toner for developing an electrostatic image is provided as a pulverized mixture including a binder resin and a colorant. The binder resin is characterized by a molecular weight distribution on a GPC chromatogram of its tetrahydrofuran (THF)-soluble resin content including below 15% of a resin component in a molecular weight region of at most 5000 and at least 5 wt. % of a resin component in a molecular weight region of at least 5.times.10.sup.6 and showing a main peak in a molecular weight region of 5000 to 5.times.10.sup.6. The THF-soluble resin component in the molecular weight region of at least 5.times.10.sup.6 is extremely enriched during a melt-kneading step during the toner production, so as to effectively prevent toner flowout from a member for cleaning a fixing roller.Type: GrantFiled: November 26, 1991Date of Patent: December 7, 1993Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Masaki Uchiyama, Yoshinobu Joh, Yasutaka Akashi, Masaaki Taya, Makoto Unno, Kazuyoshi Hagiwara
-
Patent number: 5219946Abstract: A binder resin comprises a vinyl copolymer, a mixture of vinyl copolymers, or a mixture of a vinyl copolymer and a vinyl polymer. A resin component with a molecular weight of not more than 10,000 is contained in an amount of from 5 to 50% by weight based on the whole resin. The vinyl copolymer or the mixture of vinyl copolymers has an acid anhydride group and a carboxyl group.Type: GrantFiled: November 8, 1990Date of Patent: June 15, 1993Inventors: Hirohide Tanikawa, Masaki Uchiyama, Tsutomu Kukimoto, Yasutaka Akashi, Masaaki Taya, Makoto Unno, Seiichi Takagi
-
Patent number: 5212524Abstract: A toner for developing electrostatic images, comprises a binder resin and a colorant, wherein the binder resin comprises a vinyl copolymer having an acid anhydride group, and the binder resin has a total acid value (A) of 2-100 mgKOH/g and a total acid value (B) attributable to acid anhydride group of below 6 mgKOH/g so that [(B)/(A)].times.100 is 60% or less. Because the binder resin has a specified acid value partly attributable to acid anhydride group, the toner is provided with an adequate balance between chargeability and dischargeability, so that the toner shows a stable performance under various environmental conditions. The toner is particularly advantageously constituted as a magnetic toner of fine particle sizes suitably used under application of unsymmetrical alternating bias electric field.Type: GrantFiled: August 31, 1992Date of Patent: May 18, 1993Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Yasutaka Akashi, Masaki Uchiyama, Makoto Unno, Masaaki Taya
-
Patent number: 5202731Abstract: An image forming apparatus is formed by providing a latent image-bearing member for holding an electrostatic image thereon and a toner-carrying member for carrying a prescribed magnetic toner comprising a binder resin and magnetic powder and having a particle size distribution including 12% by number or more of magnetic toner particles of 5 microns or smaller, 33% by number or less of magnetic toner particles of 8-12.7 microns and 2% by volume or less of magnetic toner particles of 16 microns or larger so as to provide a volume-average particle size of 4-10 microns. At the developing station, an alternating bias voltage comprising a DC voltage and an unsymmetrical AC voltage in superposition is applied between the toner-carrying member and the latent image-bearing member to provide an alternating bias electric field comprising a development-side voltage component and a reverse-development side voltage component.Type: GrantFiled: August 26, 1992Date of Patent: April 13, 1993Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Yasutaka Akashi, Masaaki Taya, Kuniko Kobayashi, Masaki Uchiyama
-
Patent number: 5175070Abstract: An image forming apparatus is formed by providing a latent image-bearing member for holding an electrostatic image thereon and a toner-carrying member for carrying a prescribed magnetic toner comprising a binder resin and magnetic powder and having a particle size distribution including 12% by number or more of magnetic toner particles of 5 microns or smaller, 33% by number or less of magnetic toner particles of 8-12.7 microns and 2% by volume or less of magnetic toner parcitles of 16 microns or larger so as to provide a volume-average particle size of 4-10 microns. At the developing station, an alternating bias voltage comprising a DC voltage and an unsymmetrical AC voltage in superposition is applied between the toner-carrying member and the latent image-bearing member to provide an alternating bias electric field comprising a development-side voltage component and a reverse-development side voltage component.Type: GrantFiled: September 26, 1990Date of Patent: December 29, 1992Assignee: Canon Kabushiki KaishaInventors: Hirohide Tanikawa, Yasutaka Akashi, Masaaki Taya, Kuniko Kobayashi, Masaki Uchiyama