Kabushiki Kaisha Toshiba

Olympus Imaging Corporation

Yutaka Arakawa

Akio Mizuno

Hiroshi Suzuki

Fubito Igari

Seiji Mizukoshi

Satoshi Okawa

Yasuhiko Ichikawa

Kyoji Murayama

A lens barrel includes a moving frame, a stepper motor that drives the moving frame, a screw member that rotates in accordance with rotation of the stepper motor, a screw gear that rotates in accordance with rotation of the screw member, a nut member that screws with the screw member, moves, by pressing, the moving frame, an external rotation operation ring, including a drive gear that rotates in response to external operation, that switches between a first state where the drive gear meshes with the screw gear, rotates the screw member, and drives the moving frame and a second state where the drive gear and the screw gear are not meshed, and control means that drive-controls the stepper motor in conjunction with rotation of the external rotation operation ring when the external rotation operation ring is in the second state.

Lens barrel

An optical device includes a first and second lens group, an operation member, a first and second lens group position detection unit, a storage unit, a control unit. The control unit controls the movement of the second lens group based on positional information of the first lens group detected by the first lens group position detection unit and the positional relationship information stored in the storage unit, and determines whether a control state of the second lens group is abnormal based on control positional information during the control of the movement of the second lens group and the signal corresponding to the position of the second lens group detected by the second lens group position detection unit.

Optical device

A CPU determines whether or not the disk access range designated by a read/write command from a host contains a defective sector. If the disk access range contains a defective sector, the CPU suspends disk access when a head has reached the defective sector. In this state, the CPU activates a buffer access circuit. The buffer access circuit copies data between an area of an alternate sector buffer and data buffer. The area of the alternate sector buffer stores data corresponding to the data written in the alternate sector allocated to the defective sector reached by the head.

Apparatus and method for accessing a disk containing an alternate sector

A CPU computes a maximum allowable time period for restoration of a sector in which an error occurs, on the basis of a command processing time period designated by a host, when the error occurs upon access to the disk designated by a command supplied from the host, the command processing time period enabling realtime processing. The CPU also determines the use of the computed maximum allowable time period as a maximum error retry time period. The CPU controls the retry of the sector within the determined maximum error retry time period.

Disk storage apparatus for audio visual data and retry method employed therein upon occurrence of sector error

Disclosed is a method of access control for a disk drive whereby an access operation for, particularly, sequentially and alternately executing accesses is supported. A CPU of the present disk drive sequentially and alternately executes accesses to a plurality of data tracks on a disk in response to an access request generated from a host system. During the access operation, the CPU secures time for a look-ahead operation, the time corresponding to the difference between transfer rates. Thus, sequential and alternate access operation in which the number of seek operations can be reduced can be realized.

Method and apparatus for access control in a disk drive

Magnetic recording/reproducing apparatus in which partially-missed data has priority to be transferred to the host system as dummy data over optional data in order to minimize a frame skipping area caused by the dummy data, the dummy data which is used for executing data reproduction having sufficient continuity for a viewer.

Data reproducing unit, data reproducing method of the same, and a magnetic recording/reproducing apparatus

When a host system has requested the reading of sequential data, a CPU incorporated in an HDD determines whether the data is fragmented into a plurality of data blocks on a disk. If the sequential data is fragmented, the CPU executes the control of reading the data from the disk and transferring it to the host system. In parallel with this control, the CPU also executes the control of writing the data read from the disk, to a contiguous area on the disk.

Apparatus and method for defragmentation in disk storage system

Disclosed herein is a system for controlling the process of performing a command in an HDD. The HDD comprises a register for holding the command control information supplied from a host system, a command register for holding a specific command. The HDD further comprises a CPU. The CPU fetches the command control information from the register when the specific command held in the command register is one for setting the command control information. The CPU controls the process of performing a command in accordance with the command control information, thereby to finish performing the command within a period between the time when the host system issued the command and the time when the host system issues the next command.

Apparatus and method of performing in a disk drive commands issued from a host system

When the idling state of a magnetic disk apparatus is detected by a CPU, a timer is started to measure a time started from the start of the idling state. When a predetermined time has elapsed, an error detection circuit performs a defect inspection of a magnetic disk from an access address stored in an EEPROM. When the defect in the magnetic disk is detected, the CPU refers to a table in the ROM to check a defect level. Substitute processing is performed to an area having the defect on the basis of the defect level. A host system is notified of the defect level depending on the defect level.

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Ome, Japan

Yutaka Arakawa