# US 7,609,599 B2 · Method of identifying a type of an optical disc and the device therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,599 B2 - Document ID: US7609599B2 - Status: Granted - Kind: B2 - Application number: 11/356,204 - Filed: 2006-02-17 - Published: 2007-08-23 - Granted: 2009-10-27 - Earliest claimed: 2006-02-17 - Assignees: Mediatek Inc. - Inventors: Kuan-Kai Juan - Web page: https://patentgrep.com/patent/US7609599B2 ## CPC - G11B 19/125: {involving the detection of carrier data format} - G11B 7/0903: {Multi-beam tracking systems} - G11B 7/0906: {Differential phase difference systems} - G11B 2007/0006: {adapted for scanning different types of carrier, e.g. CD & DVD} - 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 A method of identifying a type of an optical disc applied in an optical drive is provided. The optical drive at least comprises an optical pickup head. First, move the optical pickup head continually from an initial position. Then, emit a light beam on an optical disc continually and receive a reflected light beam from the optical disc to generate a servo signal. Next, detect a waveform pattern of the servo signal continually to determine whether the waveform pattern of the servo signal changes, if so, the optical disc is identified as a Digital Video Disk-Random Access Memory (DVD-RAM). ## Claims ### Claim 1 A method of identifying a type of an optical disc applied in an optical drive, the optical drive having an optical pickup head, the method comprising: moving the optical pickup head continually from an initial position across an interface of an embossed area and a rewriteable area; emitting a light beam on an optical disc continually and receiving a reflected light beam from the optical disc to generate a servo signal; and detecting a waveform pattern of the servo signal continually to determine whether the waveform pattern of the servo signal changes, and if so, identifying the optical disc as a Digital Video Disc-Random Access Memory (DVD-RAM) disc. ### Claim 2 (depends on 1) The method according to claim 1, wherein in the step of detecting a waveform pattern of the servo signal continually, if the waveform pattern of the servo signal remains unchanged, the method further comprises: proceeding with moving the optical pickup head and detecting the servo signal; stopping moving the optical pickup head if the waveform pattern of the servo signal keeps unchanged after the optical pickup head has been continually moved for a pre-determined distance, and then the optical disc being identified as a non-DVD-RAM disc. ### Claim 3 (depends on 2) The method according to claim 2, wherein the pre-determined distance is the distance between the initial position and the most inner track of the optical disc. ### Claim 4 (depends on 2) The method according to claim 2, wherein the pre-determined distance is the distance between the initial position and the most outer track of the optical disc. ### Claim 5 (depends on 1) The method according to claim 1, wherein the optical pickup head is moved from an outer track to an inner track of the optical disc when the step of continually moving the optical pickup head is performed. ### Claim 6 (depends on 1) The method according to claim 1, wherein the optical pickup head is moved from an inner track to an outer track of the optical disc when the step of continually moving the optical head is performed. ### Claim 7 (depends on 1) The method according to claim 1, wherein the step of determining whether the waveform pattern of the servo signal changes is accomplished by comparing the amplitude of the servo signal to a threshold value. ### Claim 8 (depends on 1) The method according to claim 1, wherein the step of determining whether the waveform pattern of the servo signal changes is accomplished by comparing a frequency spectrum of the servo signal generated by Fast Fourier Transform to a pre-determined frequency spectrum. ### Claim 9 (depends on 1) The method according to claim 1, wherein the servo signal is selected at least one from the group consisting of a Differential Phase Detection (DPD) signal, a Differential Push-Pull (DPP) signal, a Radio Frequency Level (RF Level) signal, a Focus Error (FE) signal, a Center Error (CE) signal and the combinations thereof. ### Claim 10 (depends on 1) The method according to claim 1, wherein the servo signal comprises a DPD signal and a RF Level signal. ### Claim 11 An optical drive comprising: a servo controller operable to move an optical pickup head based on a servo signal so that the optical pickup head emits a light beam on an optical disc continually and receives a reflected light beam from the optical disc for generating the servo signal; and a signal processing unit operable to determine whether the waveform pattern of the servo signal changes based on the servo signal; wherein the optical pickup head continually emits the light beam to the optical disc and continually receives the reflected light beam from the optical disc to generate the servo signal when the servo controller begins to move the optical pickup head continually from a initial position to across an interface of an embossed area and a rewriteable area, and the signal processing unit continually detects the waveform pattern of the servo signal; wherein the signal processing unit identifies the optical disc as a DVD-RAM disc when the signal processing unit determines that the waveform pattern of the servo signal changes. ### Claim 12 (depends on 11) The optical drive according to claim 11, wherein the servo controller is further operable to stop moving the optical pickup head, and the signal processing unit identifies the disc as a non-DVD-RAM disc if the waveform pattern of the servo signal remains unchanged after the optical pickup head has been continually moved for a pre-determined distance. ### Claim 13 (depends on 12) The optical drive according to claim 12, wherein the pre-determined distance is the distance between the initial position to the most inner track of the optical disc. ### Claim 14 (depends on 12) The optical drive according to claim 12, wherein the pre-determined distance is the distance between the initial position to the most outer track of the optical disc. ### Claim 15 (depends on 11) The optical drive according to claim 11, wherein the servo controller continually moves the optical pickup head from an outer track to an inner track of the optical disc when the optical pickup head is moved from the initial position. ### Claim 16 (depends on 11) The optical drive according to claim 11, wherein the servo signal controller continually moves the optical pickup head from an inner track to an outer track of the optical disc when the optical pickup head is moved from the initial position. ### Claim 17 (depends on 11) The optical drive according to claim 11, wherein the signal processing unit determines whether the waveform pattern of the servo signal changes in manner of comparing the amplitude of the servo signal to a threshold value. ### Claim 18 (depends on 11) The optical drive according to claim 11, wherein the signal processing unit determines whether the waveform pattern of the servo signal changes in manner of comparing a frequency spectrum of the servo signal generated by Fast Fourier Transform to a pre-determined frequency spectrum. ### Claim 19 (depends on 11) The optical drive according to claim 11, wherein the servo signal is selected at least one from the group consisting of a Differential Phase Detection (DPD) signal, a Differential Push-Pull (DPP) signal, a Radio Frequency Level (RF Level) signal, a Focus Error (FE) signal, a Center Error (CE) signal and the combinations thereof. ### Claim 20 (depends on 11) The optical drive according to claim 11, wherein the servo signal comprises a DPD signal and a RF Level signal.