Hitachi, Ltd.

Masaichi Nagai

Isao Ikuta

Yoshihito Maeda

Hisashi Andoh

Hiroyuki Minemura

Yoshio Sato

Tatsuya Sugita

Nobuyoshi Tsuboi

Yutaka Sugita

Yoshimi Kato

Yoshimi Katou

Toshiki Kaneko

Ryuji Watanabe

Tetsuya Fushimi

Nobuo Tsukamoto

Tetsuo Ito

Tetsuro Minemura

Hisashi Ando

Akio Mimura

Takeo Tamamura

Seiki Shimizu

Joo Ishihara

Youmei Shinagawa

Tetsuroh Minemura

Kiyoshi Konno

Hiroshi Suga

Atsuko Naruse

Yoshimi Katoh

A simple and convenient method of manufacturing a CMOS TFT semiconductor circuit device wherein a doping layer doped into a first conductivity type without a mask is compensated with a dopant of a second conductivity type having a high density so that the conductivity type of the doping layer of first conductivity type is inverted into the second conductivity type, and further, in order to carry out the inversion of the conductivity type by the compensation easily and reliably, the surface density of the dopant of the doping layer of first conductivity type is reduced prior to compensating with the dopant of second conductivity type.

Manufacturing method of CMOS thin film semiconductor device and CMOS

An optical information handling device in which reflectivity of the conventional reproduction-only type optical disk is lowered to 60% or less and is made equal to the reflectivity of write-once type and rewritable type optical disks, whereby interchangeability in these of these disks is possible.

ROM type optical recording medium with a high reflectivity and an

An optical disk apparatus includes a recording method in which at least one of the scanning position, the irradiation time, the irradiation start point and the irradiation power of a light beam is arbitrarily changed, and a method and apparatus in which information is represented by a plurality of recording marks without being limited to two kinds of recording and erasion. In order to prevent overlapping recording/erasion, a recording clock generating unit delays a reference clock signal to generate a recording clock signal and a recording control unit transfers user data to an optical head in synchronism with the recording clock signal so that it is recorded on an optical disk. Also, the amount of delay is recorded to enable sure reading or reproduction. At the time of reading, a servo mark detection signal is divided to generate a clock signal having a variable frequency, thereby realizing an optical disk for which high-precision recording/reproduction is possible.

Optical disk apparatus

The present invention provides an optical recording medium using an amorphous-crystalline phase-change for recording and erasing, wherein reflectivity of an optical recording medium-constituting recording film in an amorphous state is larger than that of the optical recording medium-constituting recording film in a crystalline state, or wherein absorptivity of an optical recording medium-constituting recording film in an amorphous state is smaller than that of the optical recording medium-constituting recording film in a crystalline state.

Optical recording media and information recording and reproducing units

The information processor uses a portable memory formed on a transparent substrate which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium rotatably incorporated within a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through the case which has at least a transparent light-incident portion. The case includes therein a rotation means for rotating the recording medium within the case, thereby enabling even further reduction in size of the information processor.

Optical disk memory and information processing apparatus

High density optical information recording even at room temperature is achieved by control of the diameter of crystalline portions exhibiting quantum size effects of fine semiconductor particles distributed in a dielectric matrix, using the non-crystalline to crystalline phase transition of the fine particles. The quantum size effects mean that the optical properties of the medium depend on the diameter of the crystalline portions. Various methods of recording, reproducing and erasing information using this optical recording medium are possible. The invention is applicable to other optical devices.

Methods of varying optical properties, optical devices, information

The invention relates to an optical memory in which an optical recording medium is built in a case, and also to a memory apparatus. Recording, reproducing and erasing operations are performed by irradiating light via a transparent portion of the case onto the built-in optical recording medium. The optical recording medium built in the case has face vibrations with respect to the case, because it is moved within the case. The present invention is characterized by employing such a construction for optically mitigating irregular fluctuation in reflectivity caused by this face vibration. In the optical memory of the present invention, the reflectivity fluctuation caused by an interference effect made between reflection light from the case and air, and also reflection light from the optical recording medium and air due to the relative deviation in the face vibrations, may be reduced by antireflection films provided in the case and the optical recording medium. In a memory apparatus of the present invention, the abovedescribed memory is mounted, the fluctuation in the reflectivity is monitored and laser power is varied in order to further mitigate the reflection vibrations.

Optical memory and information processing apparatus

There is provided a compact and thin optical disk unit as a memory unit suitable for a portable computer such as a book type computer and a portable recording/reproducing apparatus. In the optical disk unit, the diameter of an objective lens is limited and a beam shaping prism, a beam splitter, a mirror and a 1/4 wavelength plate are formed into a unitary structure to make easy the optical axis adjustment of an optical head and ensure highly accurate assembling.

Information processing apparatus and optical head incorporated therein

The information processor uses a portable memory which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium incorporated rotatably in a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through this case.

Information processor and disk memory used in the same

An optical recording medium, which comprises a recording layer capable of reversibly undergoing a phase change between a crystalline state and an amorphous state by irradiation of an electromagnetic energy, the crystalline state of the recording layer being composed of a single phase of substantially a three-component compound or a higher multi-component compound can attain high speed recording and high speed erasing that cannot be obtained with the conventional optical recording medium.

Optical recording medium

A matrix for magnetic separators which comprises wire or ribbon of a crystalline magnetic alloy having a fine-grained structure and a supersaturated solid solution structure.

Magnetic separator matrix of cut pieces of an elongated crystalline

In an information recording medium having a recording layer for recording information by heating through incoming energy, at least one of an interference layer and an absorption layer for the incoming energy is provided on the energy-incoming side of the recording layer to reduce the reflected energy from the information recording medium and increase the quantity of heat input into the recording layer. The temperature of the recording layer is rapidly enhanced, and rapid writing is made possible thereby. Writing or erasing can be made with less incoming energy, and thus the writing sensitivity or erasing sensitivity of the information recording medium can be increased.

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Hitachi, Japan

Masaichi Nagai