6results about "Analogue recording" patented technology

Write commands in a shingled magnetic recording (SMR) drive are efficiently executed when a write command and associated write data are received by an SMR HDD from a host while the target SMR band for storing the write data is undergoing a refresh operation. In response to the write command, the HDD suspends the refresh operation, stores the write data in nonvolatile memory, and informs the host that the write command has been completed. After the write data are stored in nonvolatile memory, the HDD resumes the refresh operation, and the remaining unrefreshed data in the target SMR band are refreshed by being rewritten to the spare SMR band. The nonvolatile memory can include the spare SMR band in some instances, the target SMR band in some instances, and in both the spare SMR band and the target SMR band in some instances.

Example control circuitry, data storage devices, and methods to use dual servo channels for burst gain switching are described. The data storage device may include two servo channels, such as the dual channels in a two-dimensional magnetic recording channel, that receive read signals for the same servo sector in parallel. One channel is calibrated to use a gain value for a first portion of the servo pattern, such as the preamble and Gray code for the servo address mark, and the other channel is calibrated to use a different gain value for a second portion of the servo pattern, such as the burst pattern. The resulting signal values may then be combined to determine the position error signal. Both channels may be configured to use different gain values for different portions of the read signal with corresponding gain switching and combining them may use the most reliable portions of each signal.

A playback device (10) (measurement device) in a record playback system (1) including a record player (100) and the playback device (10) measures a frequency characteristic of each of a plurality of input signals which are input from the record player (100) to the playback device (10) when a plurality of test signals for measuring a characteristic of the record playback system (1) are played back by the record player (100), the plurality of test signals being recorded on a phonograph record, the plurality of input signals corresponding to the plurality of test signals recorded; calculates a measurement error between the frequency characteristic of each of the plurality of input signals measured and a predetermined frequency characteristic; selects a frequency characteristic of which the measurement error is smallest from among the frequency characteristics of the plurality of input signals, as a measurement result of the record playback system (1); and outputs the measurement result selected.

Example control circuitry, data storage devices, and methods to use dual servo channels for burst gain switching are described. The data storage device may include two servo channels, such as the dual channels in a two-dimensional magnetic recording channel, that receive read signals for the same servo sector in parallel. One channel is calibrated to use a gain value for a first portion of the servo pattern, such as the preamble and Gray code for the servo address mark, and the other channel is calibrated to use a different gain value for a second portion of the servo pattern, such as the burst pattern. The resulting signal values may then be combined to determine the position error signal. Both channels may be configured to use different gain values for different portions of the read signal with corresponding gain switching and combining them may use the most reliable portions of each signal.

Write commands in a shingled magnetic recording (SMR) drive are efficiently executed when a write command and associated write data are received by an SMR HDD from a host while the target SMR band for storing the write data is undergoing a refresh operation. In response to the write command, the HDD suspends the refresh operation, stores the write data in nonvolatile memory, and informs the host that the write command has been completed. After the write data are stored in nonvolatile memory, the HDD resumes the refresh operation, and the remaining unrefreshed data in the target SMR band are refreshed by being rewritten to the spare SMR band. The nonvolatile memory can include the spare SMR band in some instances, the target SMR band in some instances, and in both the spare SMR band and the target SMR band in some instances.