Abstract: Disclosed is an antibacterial agent composition which is highly safe and has excellent antibacterial abilities, by using a silicon-containing compound that is obtained by a specific manufacturing method. The antibacterial agent composition has a more stable antibacterial component, and is capable of imparting antibacterial abilities to teeth, while being also capable of cleaning an article or the mouth. Also disclosed are: an antiviral agent composition which is highly safe and has excellent virus deactivation abilities; an antibacterializing method, a cleaning/mouth rinsing method, each using the antibacterial agent composition or the antiviral agent composition; and a method for fixing an antibacterial agent or an antiviral agent. The antibacterial agent composition may contain a silicon-containing compound which is represented by general formula (1) and obtained by reacting a specific triethoxysilyl compound in an ethanol solvent.

Abstract: Disclosed is an antibacterial agent composition which is highly safe and has excellent antibacterial abilities, by using a silicon-containing compound that is obtained by a specific manufacturing method. The antibacterial agent composition has a more stable antibacterial component, and is capable of imparting antibacterial abilities to teeth, while being also capable of cleaning an article or the mouth. Also disclosed are: an antiviral agent composition which is highly safe and has excellent virus deactivation abilities; an antibacterializing method, a cleaning/mouth rinsing method, each using the antibacterial agent composition or the antiviral agent composition; and a method for fixing an antibacterial agent or an antiviral agent. The antibacterial agent composition may contain a silicon-containing compound which is represented by general formula (1) and obtained by reacting a specific triethoxysilyl compound in an ethanol solvent.

Abstract: Disclosed is an antibacterial agent composition which is highly safe and has excellent antibacterial abilities, by using a silicon-containing compound that is obtained by a specific manufacturing method. The antibacterial agent composition has a more stable antibacterial component, and is capable of imparting antibacterial abilities to teeth, while being also capable of cleaning an article or the mouth. Also disclosed are: an antiviral agent composition which is highly safe and has excellent virus deactivation abilities; an antibacterializing method, a cleaning/mouth rinsing method, each using the antibacterial agent composition or the antiviral agent composition; and a method for fixing an antibacterial agent or an antiviral agent. The antibacterial agent composition may contain a silicon-containing compound which is represented by general formula (1) and obtained by reacting a specific triethoxysilyl compound in an ethanol solvent.

Abstract: A method for writing data to a disk drive. The method includes: receiving a write command; and, determining whether a beginning and an end of a rewrite area specified by the write command agree with boundaries of large-sized data sectors on a disk. The method also includes: reading head and tail data sectors and making a backup of the head and tail data sectors in first and second non-volatile memory areas, respectively, if the beginning of the rewrite area does not agree with the boundaries. The method includes starting a rewrite of the rewrite area after completing backups into first and second non-volatile memory areas. Moreover, the method includes: determining a state stage by using data in first, second, third and fourth non-volatile memory areas if a power shut-down occurs during execution of the write command; and, executing a recovery process in accordance with the determined state stage.

Abstract: Embodiments of the present invention help to securely manage a data cryptographic key in a data storage device. In an embodiment of the present invention, a cryptographic processor for encrypting and decrypting data is located between a host interface and a memory manager. In parts of the hard disk drive (HDD), except for the host interface, the HDD handles user data in an encrypted state. A data cryptographic key which the cryptographic processor uses to encrypt and decrypt the user data is encrypted and stored in a magnetic disk. A multiprocessing unit (MPU) decrypts the data cryptographic key using a password and a random number to supply it to the cryptographic processor. Using the password and the random number, the HDD can manage the data cryptographic key with more security.

Abstract: In one embodiment, a HDD creates a segment table to associate an address of user data in a flash memory with an LBA in a magnetic disk. The HDD updates the segment table in a DRAM and saves it to the flash memory at a specific timing. The HDD creates journals indicating the update of the segment table and saves it to the flash memory. The latest segment table can be restored using the segment table and the journals in the flash memory.

Abstract: Disclosed is an antibacterial agent composition which is highly safe and has excellent antibacterial abilities, by using a silicon-containing compound that is obtained by a specific manufacturing method. The antibacterial agent composition has a more stable antibacterial component, and is capable of imparting antibacterial abilities to teeth, while being also capable of cleaning an article or the mouth. Also disclosed are: an antiviral agent composition which is highly safe and has excellent virus deactivation abilities; an antibacterializing method, a cleaning/mouth rinsing method, each using the antibacterial agent composition or the antiviral agent composition; and a method for fixing an antibacterial agent or an antiviral agent. The antibacterial agent composition may contain a silicon-containing compound which is represented by general formula (1) and obtained by reacting a specific triethoxysilyl compound in an ethanol solvent.

Abstract: A method for writing data to a disk drive. The method includes: receiving a write command; and, determining whether a beginning and an end of a rewrite area specified by the write command agree with boundaries of large-sized data sectors on a disk. The method also includes: reading head and tail data sectors and making a backup of the head and tail data sectors in first and second non-volatile memory areas, respectively, if the beginning of the rewrite area does not agree with the boundaries. The method includes starting a rewrite of the rewrite area after completing backups into first and second non-volatile memory areas. Moreover, the method includes: determining a state stage by using data in first, second, third and fourth non-volatile memory areas if a power shut-down occurs during execution of the write command; and, executing a recovery process in accordance with the determined state stage.

Abstract: Embodiments of the present invention help to securely manage a data cryptographic key in a data storage device. In an embodiment of the present invention, a cryptographic processor for encrypting and decrypting data is located between a host interface and a memory manager. In parts of the hard disk drive (HDD), except for the host interface, the HDD handles user data in an encrypted state. A data cryptographic key which the cryptographic processor uses to encrypt and decrypt the user data is encrypted and stored in a magnetic disk. A multiprocessing unit (MPU) decrypts the data cryptographic key using a password and a random number to supply it to the cryptographic processor. Using the password and the random number, the HDD can manage the data cryptographic key with more security.

Abstract: Embodiments of the present invention improve efficiency in saving log data in a hard disk drive (HDD) equipped with a magnetic disk and a flash memory,. In an aspect of one embodiment of the present invention, a HDD creates a segment table to associate an address of user data in a flash memory with an LBA in a magnetic disk. The HDD updates the segment table in a DRAM and saves it to the flash memory at a specific timing. The HDD creates journals indicating the update of the segment table and saves it to the flash memory. The latest segment table can be restored using the segment table and the journals in the flash memory.

Abstract: Embodiments of the present invention help to suppress adverse effects on the host computer operation caused by saving a segment table. According to one embodiment, a hard disk drive (HDD) creates a segment table to associate addresses of user data in a flash memory with LBAs in a magnetic disk. The HDD updates the segment table in a DRAM and saves it to the flash memory at a specific timing. The HDD creates a journal indicating an update of the segment table and saves it to the flash memory. The segment table and the journal in the flash memory enable the latest segment table to be restored. If the HDD receives a predetermined command from a host computer, it saves the segment table in the DRAM into the flash memory.

Abstract: Embodiments in accordance with the present invention provide a data recording device that is capable of easily managing, on a user basis, data key used for data encryption, and to provide a data management method thereof. According to one embodiment, a data encryption/decryption circuit performs the steps of: encrypting write data inputted from the host side, and then outputting the encrypted write data to the magnetic disk side; and decrypting read data inputted from the magnetic disk side, and then outputting the decrypted read data to the host side. A data-key management circuit manages a data key used to operate the data encryption/decryption circuit.

Abstract: An executable command selection system and method are provided. A command is selected as the next-to-be-executed command when the execution waiting time for the command is less than or equal to a predetermined reference time. In addition, the command selected as the next-to-be-executed command has an execution waiting time greater than or equal to a scanning time. Once a command is selected as the next-to-be-executed command, calculation of execution waiting times for subsequent commands in the command queue stops. In this manner, when the number of commands in the command queue exceeds a predetermined number, the method of the present invention improves the efficiency of command execution for a storage device.

Abstract: An executable command selection system and method are provided. A command is selected as the next-to-be-executed command when the execution waiting time for the command is less than or equal to a predetermined reference time. In addition, the command selected as the next-to-be-executed command has an execution waiting time greater than or equal to a scanning time. Once a command is selected as the next-to-be-executed command, calculation of execution waiting times for subsequent commands in the command queue stops. In this manner, when the number of commands in the command queue exceeds a predetermined number, the method of the present invention improves the efficiency of command execution for a storage device.

Abstract: To provide a method of starting a data storage unit which allows a computer system to be used as early as possible. The present invention relates to a method for starting up a computer system having a data storage unit equipped with an actuator arm which supports a flexible cable. The method allows a command from the host computer to be processed before generation of corrected tension data for the flexible cable. The method includes the steps of turning on power; executing a start operation, excluding generation of corrected tension data of the flexible cable; causing an access command from a host computer to be in an executable state, following the step of executing a start operation; and executing generation of corrected tension data of the flexible cable, following the step of causing an access command from a host computer to be in an executable state.

Abstract: A disk device, track positioning method, and method for generating a position error signal in which the occurrence of a wrong correction operation can be prevented by creating an appropriate PES without using a burst pattern having a defect, and reassign sectors can be decreased by decreasing defective sectors thereby to reduce the performance degradation is disclosed. In the disk device and track positioning method, the defect of a burst pattern read out from a disk is detected, and if a defect is detected in the burst pattern, a data value corresponding to the sum data of the burst pattern pair having the defect detected is obtained by measuring the maximum amplitude value of the burst pattern pairing with the burst pattern having the defect detected, and a PES is created according to the amplitude of the burst pattern having the defect detected and the maximum amplitude value.

Abstract: A disk device, track positioning method, and method for generating a position error signal in which the occurrence of a wrong correction operation can be prevented by creating an appropriate PES without using a burst pattern having a defect, and reassign sectors can be decreased by decreasing defective sectors thereby to reduce the performance degradation is disclosed. In the disk device and track positioning method, the defect of a burst pattern read out from a disk is detected, and if a defect is detected in the burst pattern, a data value corresponding to the sum data of the burst pattern pair having the defect detected is obtained by measuring the maximum amplitude value of the burst pattern pairing with the burst pattern having the defect detected, and a PES is created according to the amplitude of the burst pattern having the defect detected and the maximum amplitude value.

Abstract: The present invention provides a disk drive device containing a cache memory having K queue entries (K is an integer) to operate in a write cache mode and a method for controlling the disk drive device. The number of the queue entries to be used in the write cache mode can be gradually decreased from the number K to a decreased number by a predetermined number, and the number of the queue entries to be used in the write cache mode can be gradually increased from the decreased number towards the number K by a predetermined number, in response to values of parameters, such as an error rate and Non Repeatable Run Out or Repeatable Run Out of the rotating data recording disk at writing of data from the cache memory to a rotating data recording disk.

Abstract: Methods and apparatus are described for a data transfer unit between a storage unit and a host, wherein a slower data transfer rate is established when a predetermined error is detected. In one embodiment the cyclicity of the error occurrence calculated and a wait is inserted between data to avoid transferring data at the calculated cyclicity point of the detected error. Optionally the data transfer unit may return the data transfer rate to the original data transfer rate or state after a predetermined time has elapsed, after a predetermined number of commands have been received, after a predetermined amount of data have been transferred, or by combination of these.

Abstract: A disk drive and a control method thereof to reduce the number of write operations to a medium while minimizing command overhead time. A disk drive 10 comprises a hard disk controller (HDC) 13, a cache memory 14, and a host interface controller (HIC) 15 with a command queue for retaining a plurality of commands which are cached in cache memory 14. The HIC 15 performs the periphery interface processing by hardware. The disk drive 10 further comprises a local microprocessor unit (MPU) 16 for controlling the overall operation of HDD 10, including operations of HDC 13 and HIC 15. The local MPU 16 instructs the HIC 15 to write data to a medium by write commands cached in the cache memory 14. When local MPU 16 retrieves a command from a plurality of write commands cached in cache memory 14 which is completely overwritten by a command more recently issued, a write operation to the medium is not performed by the retrieved command.