Sharp Kabushiki Kaisha Corporation

Tdk Corporation

Tokyo Ohka Kogyo Co., Ltd.

Mitsuo Ishii

Yukio Kurata

Tomoyuki Miyake

Kenji Ohta

Hiroyasu Inoue

Hiroyuki Katayama

Shigemi Maeda

Hiroshi Fuji

Toshihisa Deguchi

Akira Hashimoto

Shintaro Hashimoto

Yoshihisa Adachi

Yoshihiro Sekimoto

Yoshio Yoshida

Masaru Nomura

Isamu Washizuka

Nobuo Ogata

Muneo Nakayama

Masaki Aoshima

Yasuo Nakata

Toshihiro Nishimura

Atsushi Etoh

Hideyoshi Yamaoka

Junichi Washo

Shigehiro Minezaki

Sadakatsu Hashimoto

Akihiro Nammatsu

Yukihiro Inoue

Yuuichi Sato

Yoshio Takeda

Yoshitomo Kitanishi

Takaaki Miyazaki

Masaru Kakumae

Isao Fujisawa

Kazuko Inoue

Takayuki Inoue

In an information recording/reproducing device, a resting period (tm) is set to be constant regardless of a mark length of a recording mark and regardless of the number of divided recording pulses. Consequently, it is possible to provide an information recording device, an information recording method, and an information recording medium, each allowing formation of a recording mark with a uniform width by use of a low laser power and allowing reduction of the number of parameters for determining a recording waveform, when forming a long recording mark.

Recording mark formation method, information recording device, information recording method, and information recording medium

A semiconductor laser driving circuit drives a plurality of semiconductor laser devices having different objective operating voltages, and has a power source for generating power voltages for the semiconductor laser devices, a power voltage changeover means for changeover from one of the power voltages to another, a current amplification section for supplying a driving current to the semiconductor laser device with the power voltage so that the semiconductor laser device comes to have its respective objective operating voltage.

Semiconductor laser driving circuit and semiconductor laser driving method therefor

A magnetic head driving device is disclosed. The device includes an inductor for generating a magnetic field, the inductor having a pair of terminals. The device has a first auxiliary coil for storing electromagnetic energy, the first auxiliary coil being connected to one of the terminals of the inductor at a first node, second auxiliary coil for storing electromagnetic energy, the second auxiliary coil being connected to the other terminal of the inductor at a second node, first main switch connected to the first node, second main switch connected to the second node, and control circuit for receiving a first signal indicating generation of a magnetic field by the inductor and a second signal indicating the direction of a magnetic field generated by the inductor and for outputting the second signal for a predetermined period of time in accordance with the first signal to alternately turn on or off the first main switch and the second main switch.

Magnetic head driving device with prerecording energization

In a magnetic head driving circuit, switching devices are turned on/off in response to a recording signal, thereby inverting a drive current to be applied from direct current power sources to a magnetic head coil. Switching devices to be switched in connection with on/off of the switching devices are connected in parallel with dummy loads connected to the direct current power sources in series. In response to the switching of the switching devices, the magnetic head coil and the dummy load alternately function as a load of each auxiliary coil. Impedances of the dummy loads are set to be equal to the impedance of the magnetic head coil, thereby making the total load of each of the auxiliary coils fixed at any time. Since a balance can be established between a value of a drive current in one direction and that of a drive current in the opposite direction, it is possible to reduce jitter of a recording mark and enable the drive current to suddenly rise and fall.

Magnetic head driving circuit with impedance elements to balance

A magnetic head driving device with two inductors sharing a common magnetic core is disclosed. The device includes an inductor for generating a magnetic field, the inductor having a pair of terminals. The device has a first auxiliary coil for storing electromagnetic energy, the first auxiliary coil being connected to one of the terminals of the inductor at a first node, second auxiliary coil for storing electromagnetic energy, the second auxiliary coil being connected to the other terminal of the inductor at a second node, first main switch connected to the first node, second main switch connected to the second node, and control circuit for receiving a first signal indicating generation of a magnetic field by the inductor and a second signal indicating the direction of a magnetic field generated by the inductor and for outputting the second signal for a predetermined period of time in accordance with the first signal to alternately turn on or off the first main switch and the second main switch.

Magnetic head driving device with pre-recording energization with two

An external magnetic field generation apparatus is used for a recording and reproduction apparatus which records information on a magneto-optical recording medium based on the magnetic field modulation system and the light modulation system, and applies a magnetic field to the portion of the magneto-optical recording medium where the light beam is projected. The apparatus has the first electro-magnet, used for the magnetic field modulation system, for generating an a.c. magnetic field which is reversed at a high speed. The apparatus has the second electro-magnet, used for the light modulation system, for generating a strong d.c. magnetic field such that power consumption coincides with that of the first electro-magnet. The second electro-magnet is integral with the first electro-magnet. The apparatus has a driver for selecting one of the electro-magnets in response to a switching signal, and the driver supplies power to the selected electro-magnet.

External magnetic field generation apparatus capable of light intensity

A recording method for a magneto-optic memory medium of exchange-coupled type having a recording layer of a low Curie point and high coercive force and a reading layer of a high Curie point and low coercive force, which comprises the steps of: applying a magnetic field to the magneto-optic memory medium to develop a predetermined data in the reading layer, and then applying both an optical beam and a magnetic field to the magneto-optic memory medium for writing the predetermined data in the recording layer, and simultaneously verifying the data upon the writing on the basis of a Kerr effect of the optical beam caused by the reading layer.

Recording method for magneto-optic memory medium

A process for preparing an orientation film for liquid crystals which comprises forming a base layer of a thermoplastic or non-thermoplastic resin to be used for the orientation film, on a substrate for liquid crystal display, and rubbing the base layer under heating at a temperature not lower than 50.degree. C. but below the melting temperature of decomposition temperature of the resin.

Process for preparing orientation film for liquid crystals

An object lens driving device causes partial rotation of movable members holding an object lens on an X-Y frame perpendicular to the optical axis of the object lens about a resilient hinge member as a fulcrum. The movable members are supported by base members. The hinge member interconnects the movable members and the base members. Electro-magnetic coils and magnets effectuate relative rotation of the movable members with respect to the base members about the hinge member. A rotational axis passing through the hinge member also passes through the position of center of gravity of the movable members and the balanced position of moment of inertia of the movable members.

Object lens driving device

An improved optical information recording and reproducing apparatus which is capable of detecting recording errors simultaneously with recording function for reduction of recording time, without requiring particular high accuracy for an optical system, and avoiding complication in the construction and consequent large size of the optical system.

Optical information recording and reproducing apparatus

An objective lens-driving unit comprising a lens supporting means for supporting the objective lens having an optical axis vertical to a recording medium on which light beams converge through the objective lens so as to attain optical recording, optical playing and optical erasing of information on the recording medium; at least one driving means for driving said lens supporting means in the tracking direction; a driving means for driving said intermediate supporting means in the focusing direction, wherein said tracking direction-driving means comprises a magnetic circuit that produces magnetic flux in the circumferential direction of the recording medium, and a tracking direction-driving coil that is positioned to cross a gap formed in the magnetic circuit to thereby receive an electro-magnetic force due to an interaction between the magnetic field of the magnetic circuit and the current passing through said coil, said tracking direction-driving coil being positioned within the excitation area of the magnetic circuit even when said coil moves in the focusing direction.

Objective lens-driving unit

An electrochromic display device comprising a transparent substrate and a counter substrate sealingly joined together to define a cell for accommodating an electrolyte, a transparent electroconductive layer on an inner surface of the transparent substrate, a display electrode layer overlaying the transparent electroconductive layer and a counter electrode layer deposited on an inner surface of the counter substrate is featured by the provision of a transparent insulating layer between the transparent substrate and the transparent electroconductive layer.

Electrochromic display device

In an electronic calculator essentially comprising a multidigit display, a keyboard and a data processor unit, a multidigit liquid crystal display is deposited together with integral key actuators of the keyboard on a flexible circuit film which carries electrical conductor leaves in a desired pattern. The conductor leaves to be in contact with terminals of the liquid crystal display are formed to extend in the direction of length of the liquid crystal display to thereby establish room for a battery compartment.

Liquid crystal display calculator construction

Growing community of inventors

Nabari, Japan

Mitsuo Ishii