Patents by Inventor Masayasu Fujisawa
Masayasu Fujisawa 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).
-
Patent number: 6690544Abstract: A magnetic head slider including a plurality of rails adapted to face a magnetic disk. Each of the rails has a longitudinal extension direction substantially in a direction of rotation of the magnetic disk, and a protective film is provided on a floating surface of at least one of the rails. A thickness of the protective film at least in a direction transverse to the longitudinal extension direction of the at least one of the rails is not uniform in the transverse direction.Type: GrantFiled: December 17, 2002Date of Patent: February 10, 2004Assignee: Hitachi, Ltd.Inventors: Atsuko Okawa, Yasuo Hira, Hirotaka Imayama, Masayasu Fujisawa, Saburou Suzuki, Eisei Togawa, Noriyuki Saiki, Nobuo Suzuki, Hiroshi Agari, Kiyoshi Akamatsu, Hiromu Chiba
-
Publication number: 20030090840Abstract: A magnetic head slider including a plurality of rails adapted to face a magnetic disk. Each of the rails has a longitudinal extension direction substantially in a direction of rotation of the magnetic disk, and a protective film is provided on a floating surface of at least one of the rails. A thickness of the protective film at least in a direction transverse to the longitudinal extension direction of the at least one of the rails is not uniform in the transverse direction.Type: ApplicationFiled: December 17, 2002Publication date: May 15, 2003Inventors: Atsuko Okawa, Yasuo Hira, Hirotaka Imayama, Masayasu Fujisawa, Saburou Suzuki, Eisei Togawa, Noriyuki Saiki, Nobuo Suzuki, Hiroshi Agari, Kiyoshi Akamatsu, Hiromu Chiba
-
Patent number: 6504680Abstract: A method of manufacturing a magnetic head slider for a magnetic head and the magnetic slider wherein the slider has non-linear rails formed in a floating surface thereof by processing including one of reactive ion etching, sputter etching and an ion milling, and side walls of the non-linear rails are polished after formation of the non-linear rails by the processing.Type: GrantFiled: August 13, 2001Date of Patent: January 7, 2003Assignee: Hitachi, Ltd.Inventors: Atsuko Okawa, Yasuo Hira, Hirotaka Imayama, Masayasu Fujisawa, Saburou Suzuki, Eisei Togawa, Noriyuki Saiki, Nobuo Suzuki, Hiroshi Agari, Kiyoshi Akamatsu, Hiromu Chiba
-
Publication number: 20020027746Abstract: A method of manufacturing a magnetic head slider for a magnetic head and the magnetic slider wherein the slider has non-linear rails formed in a floating surface thereof by processing including one of reactive ion etching, sputter etching and an ion milling, and side walls of the non-linear rails are polished after formation of the non-linear rails by the processing.Type: ApplicationFiled: August 13, 2001Publication date: March 7, 2002Inventors: Atsuko Okawa, Yasuo Hira, Hirotaka Imayama, Masayasu Fujisawa, Saburou Suzuki, Eisei Togawa, Noriyuki Saiki, Nobuo Suzuki, Hiroshi Agari, Kiyoshi Akamatsu, Hiromu Chiba
-
Patent number: 6278582Abstract: For removing re-deposited particulates produced during an etching process of a magnetic head slider and forming a minute chamfered portion, a polishing process is carried out by using polishing cloth such as non-woven polyester fabric after having formed rails of non-linear shape on a floating surface by the etching process. Thus, the re-deposited particulates produced during the etching process are removed, whereby the reliability of the floating characteristic of magnetic head is improved.Type: GrantFiled: December 21, 1999Date of Patent: August 21, 2001Assignee: Hiatchi, LTDInventors: Atsuko Okawa, Yasuo Hira, Hirotaka Imayama, Masayasu Fujisawa, Saburou Suzuki, Eisei Togawa, Noriyuki Saiki, Nobuo Suzuki, Hiroshi Agari, Kiyoshi Akamatsu, Hiromu Chiba
-
Patent number: 6219200Abstract: A thin-film magnetic head in which the end face of a magnetic film protrudes beyond a substrate within the air bearing surface of the magnetic head. The magnetic film being made of a material containing a metallic element which is lap polished with abrasive grains containing the hydroxide of the metallic element. Because the air bearing surface is constructed according to the above procedure, the bit length of a magnetic disk can be decreased to ensure a higher record density.Type: GrantFiled: January 3, 1997Date of Patent: April 17, 2001Assignee: Hitachi, Ltd.Inventors: Yoshiharu Waki, Masayasu Fujisawa, Yukihiro Isono
-
Patent number: 6198601Abstract: A magnetic head element has one or more rails formed on the surface thereof. Each rail is formed so as to have a tapered angle of 55-85°. To form such a rail, ion milling is conducted; the rail substrate used is allowed to have an inclination angle to 15-60° and is rotated; and there is used, as the ion milling gas, a fluorinated hydrocarbon (e.g., CH2FCF3) gas alone or a mixed gas of said fluorinated hydrocarbon gas and Ar, SF6 or the like. Accordingly, a magnetic head rail shape gives a small variation in flying height between magnetic bead and magnetic disc.Type: GrantFiled: March 16, 1999Date of Patent: March 6, 2001Assignee: Hitachi, Ltd.Inventors: Yasuo Hira, Tamaki Toba, Hirotaka Imayama, Atsuko Ohkawa, Masayasu Fujisawa, Kazuo Nate, Hideki Sonobe, Saburo Suzuki, Eisei Togawa, Hiroshi Ishizaki, Yoshiki Hagiwara
-
Patent number: 6188546Abstract: The magnetic head assembly including a magnetic head having a terminal composed of a conductive film and a supporting spring. The supporting spring has interconnecting patterns (lines) on the top thereof and a projective electrode. The terminal of the magnetic head is electrically connected to the projective electrode of the supporting spring by a solderless, direct contact connection. The magnetic head is fixed to the supporting spring by using a non-electrical bonding agent. This structure makes it possible to stabilize the position of the magnetic head assembly and the relative speed variation between the magnetic head element and the magnetic disk, thereby enhancing the reliability of the magnetic disk apparatus.Type: GrantFiled: October 23, 1997Date of Patent: February 13, 2001Assignee: Hitachi, Ltd.Inventors: Yasuyuki Nakajima, Keii Ueno, Michio Takahashi, Masayasu Fujisawa, Katsuya Fukasawa, Issei Takemoto, Kooji Serizawa, Kazushige Hashimoto, Shigeo Nakamura, Yukimori Umakoshi, Mikio Tokuyama
-
Patent number: 5947796Abstract: A fine grain milling method mixes powder into a high-pressure fluid, and injects the mixture to a work material covered with a mask to form the work material to a desired shape. In addition, the method injects anther high-pressure fluid to the powder adhered to the work material to remove the powder. The method can accurately transfer the mask pattern to the work material.Type: GrantFiled: November 21, 1995Date of Patent: September 7, 1999Assignee: Hitachi, Ltd.Inventors: Hirotaka Imayama, Katsuya Fukasawa, Masayasu Fujisawa, Yoshiki Hagiwara
-
Patent number: 5910864Abstract: A magnetic head element has one or more rails formed on the surface thereof. Each rail is formed so as to have a tapered angle of 55-85.degree.. To form such a rail, ion milling is conducted; the rail substrate used is allowed to have an inclination angle to 15-60.degree. and is rotated; and there is used, as the ion milling gas, a fluorinated hydrocarbon (e.g., CH.sub.2 FCF.sub.3) gas alone or a mixed gas of said fluorinated hydrocarbon gas and Ar, SF.sub.6 or the like. Accordingly, a magnetic head rail shape gives a small variation in flying height between magnetic head and magnetic disc.Type: GrantFiled: October 22, 1996Date of Patent: June 8, 1999Assignee: Hitachi, Ltd.Inventors: Yasuo Hira, Tamaki Toba, Hirotaka Imayama, Atsuko Ohkawa, Masayasu Fujisawa, Kazuo Nate, Hideki Sonobe, Saburo Suzuki, Eisei Togawa, Hiroshi Ishizaki, Yoshiki Hagiwara
-
Patent number: 5567333Abstract: A magnetic head element has one or more rails formed on the surface thereof. Each rail is formed so as to have a tapered angle of 55.degree.-85.degree.. To form such a rail, ion milling is conducted; the rail substrate used is allowed to have an inclination angle to 15.degree.-60.degree. and is rotated; and there is used, as the ion milling gas, a fluorinated hydrocarbon (e.g. CH.sub.2 FCF.sub.3) gas alone or a mixed gas of said fluorinated hydrocarbon gas and Ar, SF.sub.6 or the like. Accordingly, a magnetic head rail shape gives a small variation in flying height between magnetic head and magnetic disc.Type: GrantFiled: June 22, 1994Date of Patent: October 22, 1996Assignee: Hitachi, Ltd.Inventors: Yasuo Hira, Tamaki Toba, Hirotaka Imayama, Atsuko Ohkawa, Masayasu Fujisawa, Kazuo Nate, Hideki Sonobe, Saburo Suzuki, Eisei Togawa, Hiroshi Ishizaki, Yoshiki Hagiwara
-
Patent number: 5560743Abstract: A fine grain milling method which mixes powder into a high-pressure fluid, and injects the mixture to a workpiece covered with a mask or pattern to process the workpiece to a desired shape. Another high-pressure fluid is injected to remove the powder adhering to the workpiece thereby enabling an accurate transfer of the mask or pattern to the workpiece.Type: GrantFiled: March 5, 1993Date of Patent: October 1, 1996Assignee: Hitachi, Ltd.Inventors: Hirotaka Imayama, Katsuya Fukasawa, Masayasu Fujisawa, Yoshiki Hagiwara
-
Patent number: 5456736Abstract: This invention provides a lap capable of reducing the pole recession produced between the substrate and the magnetic film when the air-bearing surface of a thin-film magnetic head is lapped, a lapping liquor used for such lapping, and a thin-film magnetic head having its air-bearing surface lapped by using them. Lapping is carried out by using a lap made of a material having both a phase of tin and a phase of brass with a greater rigidity in supporting the abrasive grains than tin, and a lapping liquor prepared by mixing an anionic surfactant (15) and an ampholytic surfactant (16). According to the present invention, it is possible to reduce the pole recession in the thin-film magnetic heads and to accordingly shorten the recording bit length of the magnetic discs.Type: GrantFiled: March 5, 1993Date of Patent: October 10, 1995Assignee: Hitachi, Ltd.Inventors: Yoshiharu Waki, Masayasu Fujisawa, Shigeo Aikawa, Kenya Ohashi, Yukihiro Isono
-
Patent number: 5371582Abstract: A thickness/depth measuring apparatus and method for measuring the thickness of a film forming a lattice-shaped mask and the depth of a groove formed on a workpiece during processing of the workpiece. The thickness/depth measuring apparatus and method provide for irradiating the workpiece with a coherent light beam, controlling the direction for linear polarization of the coherent light beam irradiated onto the workpiece, adjusting the incident angle of the coherent light beam irradiated onto the workpiece in a predetermined angular range, receiving and detecting reflected light reflected by the workpiece at different irradiated incident angles and including higher-order diffracted light; and calculating the thickness of the film and the depth of the groove in accordance with the intensity of the diffracted light detected.Type: GrantFiled: July 30, 1993Date of Patent: December 6, 1994Assignee: Hitachi, Ltd.Inventors: Tamaki Toba, Atsuko Ohkawa, Yasuo Hira, Masayasu Fujisawa, Isao Hashimoto
-
Patent number: 5349745Abstract: A method of fabricating a thin-film magnetic in which a mask pattern in etching a bottom pole is formed of first and second mask films in this order when viewed from the bottom pole, the first mask film is used for defining, by self-alignment, the length of that portion of the side edge of a top pole which is nearly perpendicular to a magnetic gap, the second mask film makes it possible to etch the bottom pole with high dimensional accuracy, a non-magnetic film is formed on the mask pattern having the bottom pole thereunder and the exposed region of a substrate, and the top pole is formed after the mask pattern has been exposed and removed.Type: GrantFiled: June 1, 1993Date of Patent: September 27, 1994Assignee: Hitachi, Ltd.Inventors: Takashi Kawabe, Eiji Ashida, Moriaki Fuyama, Tadayuki Iwakura, Hiroshi Fukui, Yoshikazu Tsuji, Shunichiro Kuwatsuka, Harunobu Saito, Yoshiki Hagiwara, Issei Takemoto, Masayasu Fujisawa
-
Patent number: 4712535Abstract: A method and an apparatus for severing a workpiece into wafer slices, wherein the inclined surface to be cut can be processed to remove protrusions or impressions which occur around the cut surface. The workpiece has a front end portion which is cut by a cutting tool and a rear end portion which is inclined with respect to the central position of the surface of the workpiece to be cut. This central position is the center of rotation about which the workpiece is rotated to generate a cone shape. When the workpiece is fed axially for cutting to obtain wafers, the central position of the workpiece surface to be cut is held at a constant position so that the workpiece can be cut continuously at a constant angle of inclination. The front end portion of the wafer being cut is rotated while being pulled in a direction from the workpiece until the completion of the severing operation.Type: GrantFiled: June 4, 1986Date of Patent: December 15, 1987Assignee: Hitachi, Ltd.Inventor: Masayasu Fujisawa