Brother Kogyo Kabushiki-kaisha

Riki Matsuda

Kazunari Taki

Yumiko Ohashi

Hideo Maruyama

Shigeru Suzuki

Yutaka Hattori

Kazuyuki Miyaki

Shinichi Hirahata

Shuzo Mizutani

Takuya Hamaguchi

A silicon single crystal substrate is formed with a plurality of channels that are partitioned by a plurality of partition walls and that are arranged at a pitch of 40 &mgr;m or less, for example. A filler material is then introduced into the channels to a height that matches the upper edges of the partition walls. After the filler material is hardened by heating a cover film is deposited to a thickness of 5 &mgr;m or less on the upper surface of the filler material and on the upper edges of the partition walls. As a result, the cover film has the same, flat shape as the upper surface of the filler material and the upper edges of the partition walls. Next, the filler material is removed so that the cover film remains covering the channels. Next, electrodes are formed on the cover film. A drive voltage is applied to a desired electrode to deform the cover film at a corresponding area, whereupon pressure is applied to liquid in the corresponding channel, and liquid is ejected from an aperture that is provided at the front end of the subject channel. Thus, the compact and high density liquid ejection device with a large deformation amount and with good drive efficiency can be easily manufactured.

Liquid ejection device and method of producing the same

A magnetic recording disk, for recording information, has a circular-shaped non-magnetic support formed with a plurality of tracks extending in a circumferential direction, each track of the plurality of tracks having a band-shaped contour having an upper flat surface and having a width in a radial direction, the plurality of tracks being juxtaposed in the radial direction so that adjacent tracks are separated by an inter-track gap. A magnetic layer is provided on the non-magnetic support. A protective layer is provided on the magnetic layer.

Magnetic recording disk

An optical data recording medium of the present invention includes: a substrate; a reflective material layer formed of light-reflective material, the reflective material layer being provided over the substrate; and an optical data recording layer for optically recording data therein and for optically reproducing the data therefrom, the optical data recording layer being formed over the reflective material layer. The reflective material layer is patterned so that the light-reflective material may be partly removed therefrom for selectively allowing a light beam irradiated on the substrate to pass therethrough to reach the optical data recording layer.

Optical data recording medium

An optical recording medium formed from a transparent substrate, an enhancement layer formed on the substrate, a guide layer, an interference layer, a recording layer, a protective layer, and a reflective layer. A recording region is formed on the guide layer by etching to a predetermined spiral or a coaxial circular pattern. Because the enhancement layer is formed from a compound of aluminum such as Al.sub.2 O.sub.3, it is not etched during plasma etching using a gas mixture of carbon tetrachloride and oxygen. Therefore, the recording region remains smooth and noise generated by roughness between layers can be prevented. By making the thickness of the guide layer 20 nm or more, light which passes through the guide layer and which generates multi-layer interference between the recording layer and the reflective layer is reduced and the amount of reflective light is increased, Therefore, fluctuations in the pushpull signal by the fluctuations in the thickness of the guide layer is reduced. By making the guide layer 40 nm or less thick, noise from the guide layer can be reduced.

Optical recording medium

An optical data storage medium having a continuous tracking guide strip defining a single spiral recording track, or concentric tracking guide rings defining concentric recording tracks. The tracking guide strip or rings provide(s) tracking servo information which is optically read to position an optical head relative to the data storage medium, for centering a read/write beam on a desired recording track. The tracking guide strip or rings is/are formed of a material which has a higher light absorption coefficient than that of a material of the recording track(s). A method for fabricating the storage medium, and a tracking system for the storage medium are also disclosed.

Optical data storage medium having embedded tracking information

An optical data storage medium having a substrate, and an optical storage layer with a recording track or tracks for storing information to be read by a light beam. An interference layer is formed on the substrate, such that a tracking reflector defining the recording track or tracks is formed on the interference layer. A flattening layer is formed on the interference layer such that the flattening layer covers the tracking reflector and provides a flat surface on which the storage layer is formed. Each of the interference and flattening layers has a thickness substantially equal to 80 /8 or (.lambda./8+m.multidot..lambda./2), where .lambda. represents a wavelength of the light beam as measured while the light beam is travelling through the interference and flattening layers, and m represents a natural number.

Optical data storage medium having interference and flattening layers

An optical recording disk comprises a base plate, a flat layer, an optical recording layer and a protection layer which are laminated in this order. The flat layer has a flat surface which contacts with the optical recording layer to thereby enable the optical recording layer to have a uniform thickness over the layer and make the surface of the optical recording layer flat. At least one of the other layers constituting the above optical disk other than the optical recording layer comprises a material capable of recording and reproducing information, such as a magnetooptic material, a phase-change material, an organic pigment and a pit-formable material in which the information is recordable.

A magneto-optical recording apparatus for writing information on a magneto-optical recording medium having at least one pair of magneto-optical storage layers each pair consisting of a first and a second storage layer which have at least one pair of corresponding recording segments, each pair of mutually corresponding recording segments consisting of a first recording segment provided on the first storage layer and a second recording segment provided on the second storage layer. The apparatus includes a first and a second writing/erasing head for writing and erasing information on the first and second storage layers, and a recording controller for activating one of the first and second writing/erasing heads to erase previous information already recorded on corresponding one of the first and second recording segments, while activating the other head to write first new information on the other of the first and second recording segments. Upon reception of a command to write second new information, the recording control means activating the above-indicated other head to erase the first new information recorded on the above-indicated other recording segment, while activating the above-indicated one head to write the second new information on the above-indicated one recording segment.

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Nagoya, Japan

Riki Matsuda