Teac Corporation

Other

Mitsubishi Electric Corporation

Hiroshi Tsuyuguchi

Tohru Miura

Makoto Shoji

Tsutomu Morita

Yoshiaki Sakai

Fumio Nagase

Katsuya Enami

Shozo Toma

Miya Enami

Kazuhiro Hiraki

Takahiro Sakaguchi

Yasushi Noda

Kenji Shimozawa

Tsuyoshi Osawa

Naoki Sugeta

Shinichi Aikawa

Takayuki Honda

Takashi Kamisaka

Shinichiro Tanaka

Kunihiko Murao

Kazuhiko Nakane

Kazuhiko Inoue

Akira Mashimo

Masaharu Ogawa

Takeshi Suzuki

Shinichi Fujisawa

Teruo Furukawa

Kiyoshi Fukuchi

Toshihiro Kitahara

Mitsumasa Kubo

Hiroyuki Onda

Keiji Uehara

Kazuo Yokota

Hiroshi Iwai

Yoshio Hirose

Daihachiro Takasu

Tetsuro Araki

Ryotaro Hongo

Hikaru Tamada

Sho Sugiyama

Yasuhiko Ando

Shinji Umehara

Satoshi Nakamura

Tadashi Terada

Yoshiaki Umeda

Satoru Kikuchi

Teruyoshi Nakahashi

Tohro Miura

Masakatsu Sakai

Sadao Yabuki

Takashi Numata

Shozo Touma

Makoto Shouji

Makoto Syoji

A DVD recorder system having a sleep state. When a predetermined period of a non-operation state has elapsed, a key controller switches the state of a power source circuit to interrupt voltage supply, thereby causing the system to shift to the sleep state. In this state, when a signal is input from the video input terminal, the key controller controls the power source circuit to turn ON, thereby causing the system to shift to the normal state. After recovery to the normal state, a DVD processor provides instructions to a DVD drive in accordance with recording conditions which are prestored in an EEPROM, and supplies an input video signal to the DVD drive so as to start recording. Also, when a medium is inserted in the DVD drive, the key controller detects an insertion signal to control the power source circuit to turn ON, thereby causing the system to return to the normal state.

Data recording/reproducing system using optical disk apparatus

A magnetic disk apparatus includes a spindle motor for rotating a magnetic disk. Either a first pulse-train signal or a second pulse-train signal is selectively generated. The first and second pulse-train signals are different from each other in pulse frequency. When the first pulse-train signal is generated, the spindle motor is controlled to rotate at a first rotational speed in response to the first pulse-train signal. When the second pulse-train signal is generated, the spindle motor is controlled to rotate at a second rotational speed in response to the second pulse-train signal. The second rotational speed differs from the first rotational speed.

Magnetic disk apparatus

A flexible magnetic disk drive to be USB interfaced with a computer, there being a maximum current limitation of 500 milliamperes to be carried by USB cables. The current consumption of the disk drive maximizes when both disk drive motor and stepper motor are in rotation and when, additionally, a pilot lamp glows to warn that the disk is being accessed. The invention takes advantage of the fact that the stepper motor is driven with a motor current that varies periodically with the stepping pulses, each period of the motor current being notionally divisible into approximately two halves such that the motor current is less in magnitude in the first half than in the second. A pilot lamp control circuit causes the pilot lamp to be energized only during the first half of each motor current period, resulting in the blinking of the pilot lamp. Thus the peak of the sum of the motor current and the lamp current during the first half of the motor current period can be made no more than the peak of the motor current alone during the second half.

Pilot lamp current consumption reduction system for a flexible magnetic disk drive or the like

A disk drive for use with interchangeable flexible magnetic disks of potentially different weights, comprising a disk drive motor for imparting rotation to a disk loaded therein, and a stepper motor for moving a transducer across the track turns on the disk. Since the current consumption of the disk drive motor is subject to change according to the weight of each disk being driven, a current detector circuit is provided for detecting the magnitude of the current being consumed by the disk drive motor. A current control circuit controls the magnitude of the current supplied to the stepper motor in inverse proportion to the detected magnitude of the disk drive motor current. The stepping pulse rate is also varied for making the rotational speed of the stepper motor higher with a decrease in the magnitude of the disk drive motor current. Thus the seek speed is made progressively higher as the disk weight grows less, without increasing the total current requirement of the disk drive.

Motor current consumption control system for a flexible magnetic disk drive or the like

A flexible magnetic disk drive is disclosed which is linked to a computer via a universal serial bus interface having firmware held on a read-only memory. In order to facilitate the upgrading of the firmware, an electrically erasable, programmable ROM is employed for firmware storage. Each new firmware version is issued in the form of a flexible magnetic disk which may be loaded in the disk drive just like an ordinary data disk, only with the disk drive disconnected from the computer as far as data transmission is concerned. The EEPROM is preprogrammed to identify the loaded firmware disk, erase the old firmware version on the ROM, and write the new version thereon. In another embodiment a self-testing program disk is employed in place of the firmware disk, for performing a set of tests on the disk drive including the interface. The tests are conducted automatically as the self-testing program disk is loaded in the disk drive, again with the disk drive disconnected from the computer.

Disk drive or like peripheral storage device adapted for firmware upgrading, self-testing, etc.

Magnetic disc recording/reproducing apparatus with semiconductor memory card recording/reproducing device

A data transmission device which can read information on an IC card without changing a structure of a conventional floppy disc drive is provided. The IC card includes memory elements for storing information therein. The IC card is accommodated in the data transmission device and the data transmission device is attached to the floppy disc drive so that data stored in the IC card is read via the floppy disc drive. The IC card is electrically connected to the data transmission device. A magnetic head core unit of the data transmission device is magnetically connected to a magnetic head of the floppy disc drive so as to transmit data to the floppy disc drive via the magnetic head. A waveform of data read from the IC card is changed to a waveform which is conformable to a reproduction characteristic of the floppy disc drive.

Data transmission device for reading data from a memory medium and transmitting the data to a magnetic reproducing apparatus with a reduced noise

Magnetic disc recording/reproducing apparatus with semiconductor memory

A CD-ROM drive is disclosed which usually is put to use with CR-ROMs of varying qualities which may, or may not, wobble during rotation, possibly resulting in the vibration of the complete device. On being loaded into the device, therefore, each disk is rotated at increasing speed preparatory to reading. The speed of disk rotation at which vibration due to disk wobbling builds up to a prescribed limit is held as a maximum allowable speed until the disk is unloaded. The disk is subsequently read at no more than the maximum allowable speed.

Method and apparatus for wobble-free data recovery from CD-rom or the

A system for infallibly positioning a transducer on Track Zero on a flexible magnetic disk in the face of possible sensing errors by an optical Track Zero sensor customarily build into a disk drive. The transducer has not been correctly recalibrated if it has been positioned, when the disk drive is powered on, on an invalid track existing, either virtually or actually, immediately radially outwardly of Track Zero and if the disk drive is connected to a host that commands recalibration merely by causing transducer travel radially outwardly of the disk. A recalibration control circuit is therefore provided which cancels the host command and which, instead, causes the transducer to travel a predetermined distance radially inwardly of the disk and then to travel radially outwardly until the Track Zero sensor indicates again that the transducer is positioned on Track Zero.

Transducer recalibration system and method for a rotating disk data

A pulse generating unit responds to a series of instruction pulses to generate a series of driving pulses which includes alternately occurring first driving pulses and second driving pulses. The pulse generating unit generates the first driving pulses directly in response to the series of instruction pulses. The pulse generating unit measures a predetermined delay time using a series of reference clock pulses since the unit received the first pulse of the series of instruction pulses. The pulse generating unit generates the second driving pulses after the thus measured predetermined delay time has elapsed. A motor requires an initial exciting period between a first one of the first driving pulses and a first one of the second driving pulses of the series of driving pulses, and requires a steady-state exciting period between each two adjacent pulses of the series of driving pulses. The predetermined delay time is longer than the initial exciting period. A time span between each two adjacent pulses of the series of instruction pulses is longer than a predetermined minimum instruction pulse period. A starting delay time is shorter than a time period obtained as a result of subtracting the steady-state exiting period and the predetermined delay time from the predetermined minimum instruction pulse period. The starting delay time is a time since a reference-clock generating unit started, which time is required for the magnitude of the series of reference clock pulses to reach an effective one.

Pulse generating system responding to instruction pulses for generating

A disk apparatus comprising a controller receiving commands from a command input device and controlling an entire operation of the disk apparatus. The rotating control function is coupled to the controller for controlling the first motor. The pickupmotor control function is coupled to the controller for controlling the second motor. The pickup control function is coupled to the controller for controlling a focusing operation and a tracking operation of the pickup. And the signal processing function is coupled to the controller for processing a recording signal to be recorded on the disk-shaped recording medium and a reproduced signal read out therefrom. The controller is comprised function-stop function for determining whether or not any command is received from the command input device during a predetermined period of time in a state. The disk apparatus is maintained in a predetermined mode and for stopping predetermined function among the rotating control function, the pickup motor control function, the pickup control function, and the signal processing function when it is determined that no command is received from the command input device during the predetermined period.

Disk apparatus having a power consumption reducing mechanism

A microcomputer system having a flexible magnetic disk drive and a controller therefor, with the disk drive including a stepper motor for incrementally moving a transducer from track to track on a rotating magnetic disk, and a clock which is inherently unstable in operation during a predefinable startup period thereof after being powered on. In order to enable the disk drive to internally generate stepping pulses for driving the stepper motor at twice as high a rate as by external stepping pulses from the controller without being affected by unstable clock pulses during the startup period of the clock, the controller supplies external stepping pulses to the disk drive after imparting a predetermined delay, longer than the startup period of the clock, to each series of external stepping pulses with respect to the moment a power save signal, also supplied from the controller to the disk drive, indicates that the clock and other power consuming parts of the disk drive be powered. Within the disk drive a counter counts the clock pulses for a length of time equal to half the period of each series of external stepping pulses in response to each incoming external stepping pulse, thereby providing output pulses that rise with the respective external stepping pulses. A pulse generator circuit generates internal stepping pulses in synchronism with both leading and trailing edges of the counter output pulses. Additional embodiments are disclosed.

Method and apparatus for the high speed driving of a stepper motor

An apparatus for reading at a constant angular velocity a CD-ROM or like optical disk that is designed to be driven at a constant linear velocity, thereby combining the higher storage capacity of CLV with the shorter access time of CAV. The CLV disk has clock data prerecorded all along its multiturn spiral track together with primary information to be retrieved and utilized by the user. As an optoelectric transducer traces the track, a first clock derives from the clock data a first clock signal which varies in frequency in step with the varying rate of the clock data being read on the CLV disk being driven at CAV. The recovered primary information is written on a memory being docked by the first clock signal and read out therefrom while the memory is being clocked by a second clock signal having a constant frequency, so that the information has a constant transfer rate on being read out from the memory. The information may be demodulated before or after being made constant in transfer rate.

Apparatus for constant angular velocity reading of constant linear

A power saving system for a flexible magnetic disk drive utilizes a power save signal supplied from a host system. When the power save signal indicates that the disk drive is standing by, a power saving circuit holds unpowered desired components of the disk drive such as a disk drive motor circuit, stepper motor circuit, read/write circuit and sensor circuits. The power saving circuit is constructed to permit the transducer to be recalibrated on a reference track on the disk only when the disk drive is turned on, but to inhibit such recalibration when the power save signal indicates the end of standby, thereby avoiding waste of power.

Power saving system for rotating disk data storage apparatus

Growing community of inventors

Tokyo, Japan

Hiroshi Tsuyuguchi