Hitachi Metals, Ltd.

Maruwa Bussan K.k.

Juro Endo

Shiro Murakami

Shigeo Fujii

Takateru Dekura

Masayuki Nakao

Asahiro Kuni

Kazuo Yamaguchi

Nobuyuki Akiyama

Yukiharu Takada

Yoshiharu Koike

Chitose Nakaya

Tsutomu Iimura

Shigeru Jomura

Yoshio Igarashi

Shigeru Oguma

Disclosed is a piezoelectric loudspeaker. According to the present invention, a piezoelectric loudspeaker comprises: a flat compound piezoelectric sheet in which multiple piezoelectric devices are arranged in an organic material; electrodes which are provided on respective surfaces of the compound piezoelectric sheet; an acoustic impedance matching support layer for maintaining the flat compound piezoelectric sheet in a curved shape and for matching an acoustic impedance; and a support frame for supporting the compound piezoelectric sheet at its circumference. Thus, sound reproduction with a desirable frequency properties that have little distortion can be performed.

Piezoelectric loudspeaker and a method for manufacturing the same

A synthetic lubricant comprising a compound represented by the following general formula (I): ##STR1## wherein Rf and Rf' represent a fluorine-containing polyoxyalkylene group, X and X' a polar group, Y of one or more selected from the group consisting of methylane, ethylene, propylene, oxygen, ketone, imino, sulfon and sulfur or no atom or group, and n an integer of 0 to 5, and a magnetic recording medium coated with this lubricant.

Synthetic lubricant for lubricating thin film and magnetic recording

A synthetic lubricant comprising a compound represented by the following general formula (I): ##STR1## wherein Rf and Rf' represent a fluorine-containing polyoxyalkylene group, X and X' a polar group, Y of one or more selected from the group consisting of methylene, ethylene, propylene, oxygen, ketone, imino, sulfon and sulfur or no atom or group, and n an integer of 0 to 5, and a magnetic recording medium coated with this lubricant.

A synthetic lubricant for lubricating a thin film containing a phosphonitrile ester obtained by cyclic polymerization or ring opening polymerization and represented by the following general formula (I): ##STR1## wherein n represents 3 to 10, and Rf and Rf' represent one or two groups selected from the following groups: ##STR2## wherein l represents 3 to 250, m 1 to 250, and Y one selected from the group consisting of F--, CF.sub.3 --, C.sub.2 F.sub.5 --, CF.sub.3 O--, C.sub.2 F.sub.5 O-- and C.sub.3 F.sub.7 O--; and a magnetic recording medium coated with this lubricant.

A magnetic recording device comprises a magnetic disk having a magnetic recording layer formed on a substrate, a slider, a magnetic core attached to the slider, and a magnetic head adapted to be brought into contact with and separated from the surface of the magnetic disk. In this magnetic recording device, the magnetic recording layer of the magnetic disk is made of a Co-based alloy and the slider of the magnetic head has stabilized zirconia as the main phase thereof.

Magnetic head having a stabilized zirconia slider

A magnetic recording medium has a magnetic film formed on the surface of a substrate and a protective film further formed on the surface of the magnetic film. The protective film is composed of a first layer containing at least one substance selected from the group consisting of Cr.sub.2 O.sub.3, Si, and Ge and a second layer of amorphous carbon or graphite containing amorphous carbon deposited on the front side of the first layer.

Magnetic recording medium

Magnetic recording device having a stabilized zirconia slider and a

A manufacturing process of Co-Ni magnetic recording media by sputtering Co-Ni thin film layer on a substrate in Argon atomsphere including nitrogen and heating the thin film to evaporate nitrogen from the thin film to prepare the magnetic recording media appropriate for high density longitudinal recording, wherein on sputtering the substrate is maintained at a temperature of room temperature to 300.degree. C.

Process for manufacturing magnetic recording medium

A flaw detection method for detecting flaw existing in the surface of a substantially plate-shaped examination object by making use of an interference of light. A coherent light is applied to the surface of the examination object and also to a reference mirror surface. The light reflected by the surface of the examination object and the light reflected by the reference mirror surface are made to interfere with each other to form an interference image from which the flaw is detected. The reference mirror surface is disposed at an optical inclination to the surface of the examination object. The reference mirror surface may be the reverse surface of the examination object while the obserse side of the same is being examined. Infrared coherent ray is preferably used as the coherent light.

Surface flaw detection method

A manufacturing process of Co-Ni magnetic recording media by sputtering Co-Ni thin film layer on a substrate in Argon atmosphere including oxygen or air and heating the thin film to evaporate oxygen or air from the layer to prepare the magnetic recording media appropriate for high density longitudinal recording, wherein on sputtering the substrate is maintained at a temperature of room temperature to 300.degree. C.

Method of manufacturing a magnetic media

A method is provided for inspecting defects in the surface of an object to be inspected, wherein oblique lighting and perpendicular lighting are alternately applied to a location where a defect or a foreign substance possibly exists. Brightness detected in the location under the application of oblique lighting is evaluated as a foreign substance so as to be discriminated from a defect. Defects are classified through shape recognition of a defect pattern obtained under the application of perpendicular lighting.

Growing community of inventors

Kumagaya, Japan

Juro Endo