# US 2013/0155826 A1 · Data Recording Medium, Method for Generating a Reference Clock Signal, and Data Storage Device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155826 A1 - Document ID: US20130155826A1 - Status: Published application - Kind: A1 - Application number: 13/683,174 - Filed: 2012-11-21 - Published: 2013-06-20 - Earliest claimed: 2011-11-21 - Assignees: Agency for Science, Technology and Research - Inventors: Jingliang ZHANG; Siang Huei LEONG; Zhimin YUAN; Bo LIU - Web page: https://patentgrep.com/patent/US20130155826A1 ## CPC - G11B 27/3063: {Subcodes} - G11B 5/012: Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence) - G11B 5/59616: {Synchronisation; Clocking (G11B5/59622 takes precedence)} - G11B 5/59655: {Sector, sample or burst servo format} - G11B 5/59688: {Servo signal format patterns or signal processing thereof, e.g. dual, tri, quad, burst signal patterns} - G11B 7/2403: Layers; Shape, structure or physical properties thereof - G11B 20/10046: {filtering or equalising, e.g. setting the tap weights of an FIR filter} - G11B 20/10222: {clock-related aspects, e.g. phase or frequency adjustment or bit synchronisation (dedicated sync patterns in the modulation code G11B20/1403)} - G11B 20/10259: {simultaneous timing recovery for multiple parallel tracks} - G11B 20/16: using non self-clocking codes, i.e. the clock signals are either recorded in a separate clocking track or in a combination of several information tracks - G11B 27/24: by sensing features on the record carrier other than the transducing track {; sensing signals or marks recorded by another method than the main recording} - G11B 7/0938: {servo format, e.g. guide tracks, pilot signals} - G11B 2020/1281: {Servo information} - G11B 2220/235: Multilayer discs, i.e. multiple recording layers accessed from the same side - G11B 2220/2516: Hard disks - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract Various embodiments provide a recording medium. The recording medium may include: a dedicated servo layer for providing servo information, wherein the dedicated servo layer comprises a plurality of tracks, wherein a first track comprises a first servo signal of a first frequency, wherein a second track comprises a second servo signal of a second frequency, and wherein the first servo signal and the second servo signal comprise a common single tone signal. ## Claims ### Claim 1 A recording medium, comprising: a dedicated servo layer for providing servo information, wherein the dedicated servo layer comprises a plurality of tracks, wherein a first track comprises a first servo signal of a first frequency, wherein a second track comprises a second servo signal of a second frequency, wherein the first servo signal and the second servo signal comprise a common single tone signal. ### Claim 2 (depends on 1) The recording medium of claim 1, wherein the single tone signal comprise a common signal on a cross track direction. ### Claim 3 (depends on 1) The recording medium of claim 1, wherein each servo signal comprises information for providing positioning information. ### Claim 4 (depends on 1) A data storage device, comprising the recording medium of claim 1. ### Claim 5 (depends on 4) The data storage device of claim 4, wherein the recording medium further comprises a data layer configured to record data therein. ### Claim 6 (depends on 4) The data storage device of claim 4, further comprising: a phase lock loop circuit configured to generate a reference clock signal for synchronization of at least one of read and write operations, based on the servo signals. ### Claim 7 A method for generating a reference clock signal for synchronization of at least one of a read operation and a write operation of a data storage device, the method comprising: generating the reference clock signal based on a plurality of tracks in a dedicated servo layer of the data storage device, wherein a first track comprises a first servo signal of a first frequency, wherein a second track comprises a second servo signal of a second frequency, wherein the first servo signal and the second servo signal comprise a common single tone signal. ### Claim 8 (depends on 7) The method of claim 7, further comprising: initializing a phase lock loop circuit upon reading of the first signal and the second signal, so as to generate the reference clock signal synchronous with the pre-determined frequency. ### Claim 9 A data storage device, comprising a clock reference generation circuit configured to generate a reference clock signal for synchronization of at least one of a read operation and a write operation of a data storage device, wherein the clock reference generation circuit is configured to generate the reference clock signal based on a plurality of tracks in a dedicated servo layer of the data storage device, wherein a first track comprises a first servo signal of a first frequency, wherein a second track comprises a second servo signal of a second frequency, wherein the first servo signal and the second servo signal comprise a common single tone signal. ### Claim 10 (depends on 9) The data storage device of claim 9, wherein the clock reference generation circuit comprises a phase lock loop. ### Claim 11 (depends on 9) The data storage device of claim 9, further comprising: at least two readers configured to provide synchronized reading by reading of two tracks of data at the same time. ### Claim 12 (depends on 9) The data storage device of claim 9, further comprising: an array of multiple readers configured to provide synchronized reading by reading of multiple tracks of data at the same time.