Tdk Corporation

Nihon University

Kenji Uchiyama

Hajime Utsunomiya

Suguru Takayama

Hideki Ishizaki

Hiroyasu Inoue

Masanori Kosuda

Mamoru Usami

Masanori Shibahara

Hideki Hirata

Kazuhiro Hattori

Yuzo Shimada

Hiroyuki Arioka

Isamu Kuribayashi

Toshiki Aoi

Atsuko Motai

Hirokazu Fujioka

Michiki Naganawa

The present invention aims at providing a three-axis motion table capable of ensuring smooth rotations around three rotation axes orthogonal to each other and decreasing an overall weight. The three-axis motion table according to the present invention has an outside frame (), an (e.g., approximately square) intermediate frame (), and an (e.g., approximately square) inside frame (). The outside frame () is rotatably mounted around a first rotation axis () by means of a pair of both-end supporting legs (). The intermediate frame () is rotatably mounted around a second rotation axis () by means of the outside frame (). The inside frame () is rotatably mounted around a third rotation axis () by means of the intermediate frame (). The inside frame () has a holding mechanism for a tested model (J). One of the both-end supporting legs () is provided with a first motor (M) to rotate the outside frame (). The outside frame () is provided with a second motor (M) to rotate the intermediate frame (). The intermediate frame () is provided with a third motor (M) to rotate the inside frame (). According to the above-mentioned configuration, the first through third motors (Mthrough M)rotate. The inside frame () holding the tested model (J) rotates in the space inside the intermediate frame (). The intermediate frame () rotates in the space inside the outside frame (). In this maimer, rotations are provided around the three rotation axes () orthogonal to each other. The pair of both-end supporting legs () works as a base for supporting the entire three-axis motion table (A). The pair of both-end supporting legs () is more stable than a base (B in FIG.) according to the conventional technology using only one vertical rotation axis for supporting one end. The pair of both-end supporting legs () is capable of miniaturization and weight saving.

Three-axis motion table

A dry etching is performed using a mask made of a titanium nitride under a reaction gas of a carbon monoxide with an additive of a nitrogen containing compound gas.

Dry etching method, microfabrication process and dry etching mask

A magneto-optical disc (1) includes a write/read magnetic layer (4) with high coercivity on a substrate (2) and an auxiliary magnetic layer (6) with low coercivity thereon in a magnetostatically coupled manner. Both the magnetic layers are recorded. Prior to or during reading, an external magnetic field of controlled strength is applied to initialize the auxiliary magnetic layer (6). The recorded magnetization information in the write/read magnetic layer (4) is read out by irradiating reading light from the side of write/read magnetic layer (4). Reading with improved C/N is possible.

Magneto-optical recording medium and reading method with magnetic layers

A magneto-optical disc includes a pit forming region and a groove forming region on a surface of a substrate and a recording layer covering the pit and groove forming regions. The pit forming region includes a row of pits having a width of 0.40-0.55 .mu.m and a depth of 600-900 .ANG. and the groove forming region includes a spiral groove having a width of 0.95-1.15 .mu.m and a depth of 600-900 .ANG.. The disc is recorded and read by using an optical head with an objective lens having a numerical aperture of 0.40 to 0.50 and directing linearly polarized laser light having a wavelength of 600 to 900 nm to the disc such that its electric field vector has a direction perpendicular to the groove and the pit row. Tracking, seeking and information retrieval can be done with minimal errors using the same laser light beam in both the pit and groove forming regions.

Magneto-optical disk

This invention has for its object to provide a magneto-optical recording medium at low costs, which is high in magnetic field sensitivity and reliability, and enables high C/N to be obtained even at high linear velocity. The magneto-optical recording medium of this invention includes on a substrate a first dielectric film, a recording film of a rare earth element-transition element alloy (including Fe), a second dieleetric film containing a metal element M and nitrogen N and a reflective film. In this medium, the recording film is up to 65 nm in thickness, and the respective diffusion indices of oxygen, nitrogen and metal element M in the vicinity of the boundary between the second dielectric and recording films are within the predetermined ranges, when the element distribution is measured by Auger electron spectroscopy under the predetermined conditions. The maximum value of the oxygen content in the vicinity of said boundary is 5 to 25 at %.

Magneto-optical recording medium

A magneto-optical disc is fabricated by forming a first dielectric film, a recording film of a rare earth element-transition element alloy, and a second dielectric film on a transparent substrate in the described order and further forming an intermediate film between the recording film and the second dielectric film. The second dielectric film contains at least one metal element and nitrogen. By depositing Ti, Cr or Nb to form an intermediate film of 1-28 .ANG. thick, the disc is improved in magnetic field sensitivity and reliability. By depositing Co or Ni to form an intermediate film of 1-18 .ANG. thick, the disc is improved in magnetic field sensitivity and reproduction stability.

Magneto-optical disc with intermediate film layer between a recording

An optical recording medium comprising a recording layer on a substrate and an intermediate layer between the substrate and the recording layer exhibits high reflectance and corrosion resistance when the intermediate layer comprises silicon, aluminum, oxygen, nitrogen, and at least one element selected from the group consisting of yttrium, lanthanide elements and actinide elements, and contains 0.1 to 2 atom % of the element and 20 to 90 atom % of silicon and nitrogen combined or 2 to 35 atom % of the element and 20 to 95 atom % of silicon and nitrogen combined.

Optical recording medium

An optical recording disk includes on a substrate 2, a dye recording layer 3, a lower reflective lamina 4, an upper reflective lamina 5, and a protective coat 6. The lower reflective lamina 4 is formed of Au, Pt, Ag, Al or an alloy thereof and the upper reflective lamina 5 is of a stainless steel composition or an alloy containing 30 wt % or more of Cu and at least one element selected from the group consisting of Zn, Ti, V, Ta, Cr, Mo, W, Mn, Fe, Co, Rh, Ni, Pd, Pt, Ag, Au, Al, Sn, Si, Pb, Cd, Hg, Ca, In, As, Sb, Bi, Se, Te, Ge, N and O. The disk is well reliable and less costly.

Optical recording disk

In a magneto-optical disk comprising a disk-shaped substrate including a grooved region in its surface and a recording layer covering the grooved region, the groove is defined by a pair of opposed side walls and a bottom in a radial cross section of the substrate and has a depth from the substrate surface to the groove bottom. The angle .theta. included between tangents to the side walls is at least 120 degrees, and the groove has a half-value width of 0.90 to 1.15 .mu.m and a depth of 600 to 900 .ANG.. The disk produces satisfactory values of push-pull signal level, radial contrast, and C/N ratio.

In an optical recording medium comprising a recording layer on a substrate, a reflective layer in the form of a Cu-Ag or Cu-Au alloy thin film is formed on the recording layer. The Cu-Ag alloy contains 5-40 atom% of Ag and the Cu-Au alloy contains 5-99 atom% of Au. The reflective layer has enough high reflectivity, corrosion resistance, and hardness to provide optical recording medium with improved eye pattern, minimized jitter and minimized error rate.

Optical recording medium having a reflective layer made of Cu-Ag or

An optical recording medium comprising a recording layer on a substrate and a protective layer formed adjacent to the upper or lower surface of the recording layer is more durable and corrosion resistant when the protective layer has a composition comprising silicon, a divalent metal such as Ba, Ca or Sr, oxygen, and nitrogen. An intermediate layer containing silicon, a metal or metalloid such as aluminum or lanthanum, oxygen and nitrogen is formed between the protective layer and the recording layer.

An optical recording medium comprising a recording layer on a substrate is more durable when an intermediate layer of a composition comprising a rare earth element oxide, silicon oxide, and silicon nitride is formed between the substrate and the recording layer.

An optical recording medium comprising a recording layer on a substrate and a protective layer formed adjacent to the upper and/or lower surface of the recording layer is more durable and corrosion resistant when the protective layer has a composition comprising, in % by weight, 40-60% of SiO.sub.2, 0.5-10% of an alkali metal oxide, 10-59.5% of Al.sub.2 O.sub.3 and/or B.sub.2 O.sub.3, and optionally up to 50% of a divalent metal oxide.

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Nagano, Japan

Kenji Uchiyama