Nec Corporation

The Furukawa Electric Co., Ltd.

Uacj Corporation

Naoki Kitamura

Kotaro Kitawaki

Hiroshi Nishimoto

Hideki Takahashi

Takuya Murata

Toshihiro Nakamura

Hideyuki Hatakeyama

Sadayuki Toda

Satoshi Yamazaki

Takashi Nakayama

Junichi Sasaki

Ryo Sakamoto

Makoto Yonemitsu

Masataka Itoh

Wataru Kumagai

Ryohei Yamada

Kimie Imakawa

Yuji Minota

Akira Hibino

Masanobu Onishi

Keita Yoshimura

This magnetic disk device is a 3.5-inch magnetic disk device equipped with magnetic disks formed from an aluminum alloy substrate. The magnetic disks arranged in a stacked manner have a thickness Td of 0.3 mm to 0.6 mm, the number N of magnetic disks involved is 10 to 16, and spacers disposed between the magnetic disks have an outside diameter 2 Rso of 35 mm to 65 mm. The outside diameter 2 Rso (mm) of the spacers satisfies 2 Rso≥−60 Td+70 and 2 Rso≤−0.5 N−+16.5 N−73.

Magnetic disk device

An aluminum alloy substrate () for magnetic disk satisfies at least two of three inequalities of an inequality group [A] and satisfies all of four inequalities of an inequality group [B], or satisfies at least two of the three inequalities of the inequality group [A] and satisfies all of four inequalities of an inequality group [C], when a plate thickness of the disk at a position (b1) is defined as t, a plate thickness at a position (b2) is defined as t, a plate thickness at a position (b3) is defined as t, a plate thickness at a position (a1) is defined as t, a plate thickness at a position (a2) is defined as t, and a plate thickness at a position (a3) is defined as t.

Aluminum alloy substrate for magnetic disk, disk drive device, method for manufacturing aluminum alloy substrate for magnetic disk, and method for measuring aluminum alloy substrate for magnetic disk

There are provided: an aluminum alloy magnetic disk substrate including: an aluminum alloy base material including an aluminum alloy containing 0.4 to 3.0 mass % (hereinafter, simply referred to as '%') of Fe, 0.1 to 3.0% of Mn, 0.005 to 1.000% of Cu, and 0.005 to 1.000% of Zn, with the balance of Al and unavoidable impurities; and an electroless Ni&#x2014;P plated layer formed on a surface of the aluminum alloy base material, in which the peak value (BLEI) of Fe emission intensity at an interface between the electroless Ni&#x2014;P plated layer and the aluminum alloy base material, as determined by a glow discharge optical emission spectrometry device, is lower than Fe emission intensity (AlEI) in the interior of the aluminum alloy base material, as determined by the glow discharge optical emission spectrometry device; and a method for producing the aluminum alloy magnetic disk substrate.

Aluminum alloy magnetic disk substrate and method for producing same

The present invention provides: an aluminum alloy substrate for magnetic discs with excellent plating surface smoothness; a manufacturing method therefor; and a magnetic disc using said aluminum alloy substrate for magnetic discs. The present invention is an aluminum alloy substrate for magnetic discs, a manufacturing method therefor, and a magnetic disc using said aluminum alloy substrate for magnetic discs, the aluminum alloy substrate being characterized in being obtained from an aluminum alloy containing Mg: 2.0-8.0 mass % ('%' below), Be: 0.00001-0.00200%, Cu: 0.003-0.150%, Zn: 0.05-0.60%, Cr: 0.010-0.300%, Si: 0.060% or less, Fe: 0.060% or less, the balance being obtained from Al and unavoidable impurities.

Aluminum alloy substrate for magnetic discs and manufacturing method therefor, as well as magnetic disc using said aluminum alloy substrate for magnetic discs

If a user pushes an operating memberin a state in which a caseof an optical transceiveris locked in a cage, a leveris turned to the front of the optical transceiver. If the user pulls out the turned lever, a projection provided on an actuating pieceabuts a convex portionso that an end of the actuating pieceprojects below the case. If a plate spring portionof the cageis pressed and elastically displaced by the end of the actuating piece, a lock portionof the casecomes off a locking holeof the plate spring portion, and the optical transceivercan be pulled out of the cage

Mechanism for releasing lock between optical transceiver and cage, optical transceiver, communication apparatus and method of releasing lock between optical transceiver and cage

There is disclosed a waveguide-type wavelength multiplexing optical transmitter/receiver module which is composed of an optical demultiplexer having an optical waveguide substrate and a filter disposed on an optical waveguide substrate, a laser diode and a photodiode. On the optical waveguide substrate, a first optical waveguide and a second waveguide are formed. On a first end face of the optical waveguide substrate, there is a cross section in which these optical waveguides cross each other. On a second end face of the optical waveguide substrate, there is an optical fiber and ports for connecting the laser diode. The filter reflects light with a wavelength of &lgr;1 from the laser diode and allows light with a wavelength of &lgr;2 from the optical fiber to pass therethrough. The laser diode is so disposed that the location of a center axis is shifted in the direction of the first optical waveguide relative to a cross axis being normal to a first end face. The photodiode does not receive an unwanted light with a wavelength of &lgr;2 or so from the laser diode. The waveguide-type wavelength multiplexing optical trans-mitter/receiver module having excellent light receiving characteristics is realized.

Waveguide-type wavelength multiplexing optical transmitter/receiver module

The integrity of a solder jointing pad, which is used to mount an optical module, is enhanced by avoiding exposure to high temperatures used in the formation of an accompanying optical wave guide. The enhanced integrity of the solder jointing pad permits a mounting solder bump to be evenly distributed on the pad, which improves mounting position characteristics. The solder jointing pads are elongated in shape and arranged in parallel and perpendicular orientation with respect to an optical transmission path in the optical module. The enhanced integrity of the solder jointing pads permits a precise amount of solder to be introduced to the pads when mounting the optical module. The optical module can then be precisely positioned simply by varying the amount of solder introduced to the solder jointing pads. The optical device can be positioned with high accuracy by taking advantage of the self-alignment action which occurs between the molten solder bumps and the solder jointing pads. The optical module can thus be precisely positioned during manufacturing, without the need for additional adjustments.

Optical module for optical transmission and manufacturing process therefor

An optical coupler having a substrate; an optical waveguide provided on the substrate; a multimode fiber optically coupled with the optical waveguide; and a single mode fiber optically coupled with the optical waveguide, the optical waveguide provided on the substrate having a multimode waveguide and a plurality of single mode waveguides, the multimode waveguide being optically coupled with the multimode fiber, the single mode waveguide being optically coupled with the single mode fiber. The above constitution can suppress the creation of branch loss.

Optical coupler

An optical coupling circuit includes an optical waveguide having an optical waveguide forming layer having a lower clad layer, a core layer and an upper clad layer. An optical element is mounted on an optical element mounting portion formed by removing a portion of the optical waveguide forming layer. The optical coupling circuit optically couples an end face of the exposed thin waveguide and the optical element mounted on the optical element mounting portion. In such optical coupling circuit, at least one thin film is inserted in the optical waveguide forming layer, and, in the thin film, there is a part of said thin film removed at said optical element mounting portion. Mass-production of the optical coupling circuit and simplification of the fabrication process can be achieved. A reference plane in the height direction is stably formed in the wafer, and heat radiation or removing of the light emitting element can be performed.

Optical coupling circuit and fabrication process therefor

Disclosed is an optical transmitter-receiver module, in which an optical waveguide with an optical dividing function is formed from a first end to a second end of a waveguide substrate, and the non-branched side of the optical waveguide is optically connected to an optical fiber at the first end of the waveguide substrate, and two optical waveguides on the branched side of the optical waveguide are optically connected to an optical transmitter and an optical receiver, respectively. A first optical waveguide of the two optical waveguides is optically connected to the optical receiver at the second end of the waveguide substrate, and a second optical waveguide of the two optical waveguides comprises a turning optical waveguide which is turned back from the second end to the first end of the waveguide substrate, and the turning optical waveguide is optically connected to the optical transmitter at the first end of the waveguide substrate.

Optical transmitter-receiver module

In an optical coupling device for optically coupling an optical fiber to an optical waveguide formed on a crystalline substrate, the optical fiber is placed in a V-shaped groove formed on the substrate by anisotropic etching. The V-shaped groove is not linearly continuous, but intermittent to intermittently support the optical fiber. The intermittence of the V-shaped groove decreases undesired width expansion of the V-shaped groove. For this structure, a light axis alignment between the optical fiber and the optical waveguide is enhanced.

Optical coupling device

A cladding layer covers a part of a substrate and two core layers are formed in the cladding layer. The two core layers merge with each other and a head of a common part of the two core layers appears on a side wall of the cladding layer. A guide portion is located near the side wall. A reflective body having an end face coated with a reflective film is positioned by the guide portion so that the head of a common part of the two core layers adheres to the reflective film.

Waveguide-type optical path converter for converting a propagation

In a waveguide-type optical device, two optical waveguides are formed in a substrate of LiNbO.sub.3 or LiTaO.sub.3. On the substrate and the two waveguides, a blocking layer is formed to block a diffusion of Li ions from the substrate. On the blocking layer, a buffer layer made from SiO.sub.2 is formed. Each of the electrodes, from which operation voltages are supplied, covers each coupling part of the two optical waveguides, respectively, via the blocking layer and the buffer layer.

Growing community of inventors

Tokyo, Japan

Naoki Kitamura