Hitachi, Ltd.

Hitachi Koki Co., Ltd.

Yoshihito Maeda

Masaichi Nagai

Isao Ikuta

Hisashi Andoh

Tatsuya Sugita

Hiroyuki Minemura

Yoshio Sato

Nobuyoshi Tsuboi

Yutaka Sugita

Yoshimi Kato

Yoshimi Katou

Toshiki Kaneko

Ryuji Watanabe

Tohru Sasaki

Akira Arimoto

Yoshiharu Nagae

Masahiko Ando

Tetsuya Fushimi

Masaaki Kitajima

Nobuo Tsukamoto

Tetsuo Ito

Tetsuro Minemura

Seiji Maruo

Osamu Itoh

Hisashi Ando

Seiki Shimizu

Kiyoshi Konno

Atsuko Naruse

Yoshimi Katoh

A reflective-type display device having a light modulating layer, including a host dispersed with light scatterers, which is held between two transparent electrodes; and a light absorbing layer disposed in back of the light modulating layer. The size of each light scatterer or the nearest distance between the adjacent light scatterers is nearly equivalent to the wavelength of incident light at least in two-dimensional directions. The refractive index ratio relative to incident light between the light scatterers and host is changed from 1 to 1.5 or more depending on the magnitude of a voltage applied across the electrodes.

Reflective-type display device having a refractive index ratio between

An optical arrangement for an optical scanning apparatus which can record a plurality of high precision information concurrently, provides for a laser beam emitted from a single light source to be polarized in two polarization directions, and each of the two polarized beams is further imparted with different information according to its polarization direction. Then, the two polarized beams are used for scanning over a photosensitive member to concurrently record respective information at different positions on the photosensitive member. In order to suppress induced light fluctuation depending on an incident angle of light on the beam splitter, an optical rotation means is provided in the optical system, such that a desired optical rotation control can be obtained corresponding to the incident angle on the beam splitter, so as to compensate for the fluctuation of light whereby the beam splitter can be arranged to be free of the influence of the incidence angle of the beam.

Optical beam scanning system with rotating beam compensation

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

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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Mito, Japan

Yoshihito Maeda