Sharp Kabushiki Kaisha Corporation

Nobuyuki Horie

Toshihiro Yamanaka

Yoshiki Nishioka

Noriaki Sakamoto

Shigemi Maeda

Daiji Yamane

Toshihisa Deguchi

Takeshi Yamaguchi

Shozou Kobayashi

Teruki Sugiura

Yoshio Yuki

Toshiaki Fujikawa

Kunio Kojima

Aisaku Taguchi

Noriaki Sakamoro

A maintenance information communication terminal, the terminal exchanging maintenance information on an apparatus to be maintenanced with a maintenance information management host, the terminal and the host being connectable together by a line, the apparatus connected to the terminal, the terminal comprising: a host number memory section that stores a telephone number of the host; a terminal call origination section that originates a call to the host of the stored telephone number so that the host recognizes a telephone number of the terminal; and a ringing duration controlling section that controls a ringing duration of the call so as to halt the call before the host connects the line and thereby to request the host to start communication.

Maintenance information communication terminal, image forming apparatus provided with same, maintenance information management host, and communication method

A recording and reproducing apparatus including a defects-list storing section for storing a defects list of a list area of an optical disk provided with a defective sector alternate function, an alternate sector storing area for storing data of an alternate sector of the optical disk, and a writing and reading controlling section for writing the defects list and the data of the alternate sector indicated by the defects list in the defects-list storing section and the alternate sector storing area when the optical disk is loaded in the main body of the apparatus. Since the data of the defective sector is written in the alternate sector storing area in advance, it is possible to read the data based on the defects list whenever necessary. Consequently, there is no need to scan the alternate sector of the optical disk, thereby reducing a lowering of the data transmission speed.

Recording and reproducing apparatus

A test mode switching system includes a register for storing test signal data and for outputting the test signal data to a self testing circuit for checking whether or not the LSI operates correctly. A memory stores a test inhibiting signal and a test allowing signal received from a CPU through the control signal terminal of the LSI. The register is enabled to output test signals depending on the condition of the output of the memory whereby the LSI can operate either under a normal operation mode or under a test mode.

Test mode switching system for LSI

A motor stop control device for stopping a motor rapidly. The motor control includes a pulse generator for generating a pulse signal having a pulse width which is in relation to the speed of the motor, a CPU, and a drive for driving the motor. When a motor stop command signal is produced when the motor being rotated forward, CPU operates the drive to produce a counter drive torque, and, at the same time, CPU starts to compare the pulse width of the present pulse signal with that of the previous pulse signal, and produces a signal when the pulse width of the present pulse signal becomes shorter than that of the previous cycle. When the signal is produced, the drive stops to produces the counter drive torque.

Motor stop control device

A transducer access control system for use in a disk recording/reproducing apparatus for moving a transducer a required distance from its present position over a disk in the radial direction thereof, includes a linear motor for driving the transducer, a circuit for generating a distance signal indicative of the required distance for moving the transducer, and a calculator for calculating a half distance which is a half of the required distance. To move the transducer for the required distance D, the linear motor is operated at the velocity controlled in accordance with a reference velocity signal produced from a reference velocity generator. The reference velocity is determined such that, the reference velocity is maintained at a predetermined value during the movement of the transducer in the first half of the required distance, and gradually decreases during the movement of the transducer in the second half of the required distance.

Transducer access control system

An optical disk apparatus comprises a light emission detection circuit which converts a light emission from a light source into an electric signal and releases it as a light emission signal, a photo detector which releases an output signal upon reception of a reflected light from a disk and/or stray lights, a correction signal generating circut which adjusts a prescribed gain in accordance with the amount of stray light, and generates a correction signal by attenuating the light emission signal based on this gain, a subtracter in which the correction signal is subtracted from the output signal of the photo detector, and disk discharging means for discharging the disk from the optical disk apparatus, when the disk is present in the optical disk apparatus during the adjustment of the above-mentioned gain. The optical disk apparatus is arranged such that an optimum gain may be obtained even when the disk is present inside the optical disk apparatus, since the disk is discharged from the optical disk apparatus by the disk discharging means during the adjustment of the gain. Thereby an accurate tracking error signal and focus error signal may be otained by correcting the output signal of the photo detector.

Servo control gain adjustment for an optical disk apparatus

A device for controlling an access operation of an information recording and reproducing device to a target position for rough access in a disk-shaped recording medium prior to a precision access to a final target position, including a head carried by an actuator, a scale, a counter, a comparator, a timer, and a controller. The scale emits pulses while the head is traveling. The counter counts the pulses and then provide the count to the comparator, which calculates a difference between the count and an access distance to be traveled for rough access and then compares the difference with a value which is determined in advance in consideration of a tolerable error. The comparison result is input into the controller. If the comparison result received when the timer finishes measuring the specified time indicates that the difference between the access distance and the count falls within the range of the predetermined value, the controller decides that the actual rough access operation has been normally finished as desired, thereby decreasing a wrong judgement with respect to finish of the rough access irrespective of a value counted by the counter.

Device for controlling an access operation of an information recording

A magneto-optic storage media is provided with two defect information blocks for storing information concerning a defect. At the time of reproduction, both the blocks are read, and it is determined whether or not the reading operation is normal. If the reading operations of both the blocks are normal, it is determined which of the respective numbers= of registrations of the information concerning a defect stored in both the blocks is larger so that the block in which the number of registrations is larger is utilized. Then, the defect information in the block which was not employed is updated and registered with the defect information. if the defect information is not registered, the block is switch so that an updating and registering operation can be executed again.

Method for managing information on a storage media without losing

A recording and reproducing apparatus is provided which includes a recording condition control device for controlling recording conditions during recording of a binary-coded original recording signal on a recording medium, a signal recording device for recording the original recording signal onto the recording medium according to recording conditions set by the recording condition control device, a reproducing signal output device for outputting binary-coded reproducing signals by detecting the recording signal as recorded on the recording medium by the signal recording device, and a recording condition setting device for obtaining the recording conditions to provide a reproducing signal approximately equal to the original recording signal through a comparison between the reproducing signal outputted from the reproducing signal output device and the original recording signal.

A disk recording checking method in which recording is performed on a disk having radially different recording tracks each divided circumferentially into a plurality of sectors. The method employs a continuous writing device for continuously writing data onto a predetermined number of the sectors, and a continuous checking device for checking the data, while continuously reading the data from the predetermined number of the sectors. The method utilized checks both the number of errors in each code sequence and the total number of errors in each sector to determine if the data in the sector is valid.

Disk recording checking method for determining if a disk is defective by

A disk recording method in which recording is performed on a disklike recording medium having a radially coaxial or spiral recording track that is divided into a predetermined plural number of recording sectors each acting as a recording unit. A predetermined number of dedicated sectors are provided at a rear portion of the recording track so that the contents that are recorded in defective sectors of the recording sectors are alternatively assigned to the dedicated sectors.

Method of disk recording using alternative recording tracks

A floppy disk drive system with a stand-by mode that shuts off power to the drive circuits that drive the head-positioning motor and the disk drive motor. The stand-by model is activated when no motor-activating signal is input within a predetermined period of time. As a result, this unique stand-by mode significantly reduces the power consumption of the floppy disk drive unit. At the same time, the stand-by mode extends the service life of several important components, such as the head-positioning pulse motor. When the stand-by mode is entered from the normal mode, the current position of the head is stored. Then when the normal mode is to be reentered from the stand-by mode, the head is first moved to a reference track and then back to the position at which the stand-by mode was entered so that the value of the two counters is equal.

Floppy disk drive with stand-by mode

A floppy disk driving circuit comprises a memory circuit for storing a plurality of items of delay time of a pair of erase heads from the switching-ON and the switching-OFF of a read/write head for all the tracks of a floppy disk, a control circuit responsive to the memory circuit for controlling ON- and OFF-delay timing of the pair of erase heads based on the plurality of items of delay timing. The plurality of items of suitable timing are previously calculated in connection with the respective tracks of the disk and stored within the memory circuit.

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Yamatokoriyama, Japan

Nobuyuki Horie