Toshiba and Toshiba Electronic Devices and Storage Assigned Nine Patents

Setting upper limit value of number of write times and magnetic disk
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,546,601) developed by Ichihara, Kazuhito, Tachikawa Tokyo, Japan, for “method of setting upper limit value of number of write times and magnetic disk device.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”A method of setting an upper limit value of the number of write times, which is applied to a magnetic disk device including a disk and a head configured to write data to the disk and read the data from the disk, includes measuring a plurality of bit error rates in a recording area of the disk upon repeatedly writing to an area of the disk adjacent to the recording area a number of write times, deriving a function that approximates a bit error rate in relation to a number of write times, using the measured bit rates corresponding to at least a first number of write times, a second number of write times, and a third number of write times, and applying the function to determine a number of write times that correspond to a first threshold bit error rate that makes the data on the disk unreadable, and setting the determined number of write times as the upper limit value of the number of write times.”

The patent application was filed on March 1, 2019 (16/290,389).

Magnetic disk device and write processing
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,540,999) developed by Kawabe, Takayuki, Sagamihara Kanagawa, Japan, for “magnetic disk device and write processing method.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that obtains a gain to be changed according to a first value calculated based on first position information of the head and second position information of the head when writing a first track to the disk, calculates third position information of the head calculated based on the gain and the second position information, and writes a second track adjacent to the first track in a radial direction according to the third position information.”

The patent application was filed on February 25, 2019 (16/284,238).

Magnetic disk device with first and second welded portions
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,535,377) developed by Aoki, Kenichiro, Machida Tokyo, Japan, for a “magnetic disk device with first and second welded portions.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a head which processes data on the recording medium and a housing including a base accommodating the recording medium and the head and a cover including a welded portion laser-welded to the base. The welded portion includes a first welded portion welded by a first weld width and a second welded portion welded by a second weld width greater than the first weld width.”

The patent application was filed on February 28, 2018 (15/907,729).

SMR-HDD media cache copy transfer
Kabushiki Kaisa Toshiba, Tokyo, Japan, have been assigned a patent (10,529,374) developed by Hall, Andre C., Fremont, CA, for a “SMR-HDD media cache copy transfer.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”A shingled magnetic recording, (SMR) hard disk drive, (HDD) receives a read command for data associated with a range of logical block addresses, LBAs). In situations where a first portion of valid data associated with the range of LBAs is stored in an SMR region of the HDD and a second portion of valid data associated with the range of LBAs is stored in a non-SMR region of the HDD, the first portion is read from the SMR region in a single disk access and copied to a first buffer of the HDD, and the second portion is read from the non-SMR region in one or more disk accesses and copied to a second buffer of the HDD. The valid data associated with the range of LBAs stored in the second buffer are copied to the first buffer to be combined with valid data associated with the range of LBAs stored in the first buffer, and the combined valid data is then transferred to the host to complete execution of the read command.”

The patent application was filed on March 7, 2017 (15/452,507).

Correcting position offset of heads on two dimensional magnetic recording
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,529,365) developed by Tagami, Naoki, Yokohama Kanagawa, Japan, Hara, Takeyori, Kawasaki Kanagawa, Japan, and Koizumi, Gaku, Yokohama Kanagawa, Japan, for a “method for correcting position offset of the heads on two dimensional magnetic recording device.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”According to one embodiment, a magnetic disk device includes a disk, a head including a write head and a first and a second read head, and a controller configured to generate a correction value based on placement information on the write head and the first and the second read head, a first distance between the first read head and the second read head in a case where the first read head is placed at a first position of the disk, and a second distance between the first read head and the second read head in a case where the first read head is placed at the first position, and to correct positions of the heads based on the correction value in a case where first data written with the first read head placed at the first position is read.”

The patent application was filed on August 27, 2018 (16/112,922).

Magnetic disk capable of reallocating address corresponding to defective sector to alternative sector
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,515,664) developed by Urata, Yukio, Sagamihara Kanagawa, Japan, for a “magnetic disk device capable of reallocating address corresponding to defective sector to alternative sector.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”According to one embodiment, a magnetic disk device includes a disk that includes a plurality of tracks, each track including a plurality of sectors for storing data, a head that is for writing data to the plurality of sectors and reading data from the plurality of sectors, and a controller. The controller is configured to determine that a first sector of the plurality of sectors is not able to be read and is a defective sector, determine that a second sector of the plurality of sectors is disposed along a line that extends through the first sector and a defective sector included in a first list of defective sectors, register the second sector in the first list of defective sectors, and reallocate an address corresponding to the second sector to a first alternative sector included on the disk.”

The patent application was filed on September 2, 2018 (16/120,291).

Magnetic disk device configured to write parity data
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,504,550) developed by Maruyama, Syosuke, Machida Tokyo, Japan, Furuhashi, Kana, Kawasaki Kanagawa, Japan, and Kondo, Yosuke, Fujisawa Kanagawa, Japan, for a “magnetic disk device configured to write parity data that is based on data being written to a parity sector when no error is detected in writing the data being written.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”A magnetic disk device includes a plurality of tracks and a controller. The controller receives write data to be written to a first sector of a track, generates a first data string based on the write data and a logical identifier for the first sector, attempts to cause the first data string to be written to the first sector, determines whether a write error has occurred while the first data string is written to the first sector, generates a second data string based at least in part on the first data string, and in response to determining that no write error has occurred while the first data string is written to the first sector, writes a parity data string that is based at least in part on the second data string to a second sector of the track that stores parity data for the track.”

The patent application was filed on September 2, 2018 (16/120,290).

Magnetic disk
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,504,543) developed by Koizumi, Gaku, Yokohama Kanagawa, Japan, for a “magnetic disk device.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”According to one embodiment, a magnetic disk device includes a magnetic disk, a recording head and a controller configured to control the recording head. The recording head includes a high-frequency oscillator disposed in a write gap formed between a main magnetic pole and a return magnetic pole, and a bias voltage application circuit configured to apply a bias voltage to the high-frequency oscillator. The controller includes a bias voltage controller configured to change a bias voltage to be applied to the high-frequency oscillator in accordance with a sampling frequency of data before the data is recorded on the magnetic disk by the recording head.”

The patent application was filed on January 15, 2019 (16/247,821).

Magnetic disk and method for suppressing disturbance component having harmonic
Kabushiki Kaisa Toshiba, Tokyo, Japan, and Toshiba Electronic Devices and Storage Corporation, Tokyo, Japan, have been assigned a patent (10,497,385) developed by Matsuzawa, Takuji, Chiba, Japan, Hara, Takeyori, and Kawabe, Takayuki, Kanagawa, Japan, for “magnetic disk device and method for suppressing disturbance component having harmonic.“

The abstract of the patent published by the U.S. Patent and Trademark Office states: ”According to one embodiment, a magnetic disk device includes a disk, a head, and a controller that estimates a first frequency component resulting from a disturbance in a first range of a frequency corresponding to the disturbance in a signal with the disturbance, estimates a second frequency component corresponding to a second frequency of a positive integral multiple of 2 or larger of a first frequency of the first frequency component in a second range different from the first range, and suppresses a first harmonic component corresponding to the positive integral multiple of the first frequency in a position error of a target position of the head on the disk.”

The patent application was filed on January 15, 2019 (16/247,938).