Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
  • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
  • G11B7/006—Overwriting
  • G11B7/0062—Overwriting strategies, e.g. recording pulse sequences with erasing level used for phase-change media

Definitions

• the present disclosure relates to a method and a device for permanently erasing data of an optical disk in an optical disk drive including an optical disk emulation.
• Examples of the high-density rewritable optical recording medium include a blue lay disk (BD), a high definition digital versatile disk (HD-DVD), etc.
• the DVD has an about 4.7 GB recording capacity and the BD has an about 25 GB recording capacity.
• the next generation high density/ultra miniature optical storage device After the BD standard has been introduced, the next generation high density/ultra miniature optical storage device has been developed. Examples of the next generation high density/ultra miniature optical storage device include technologies such as super- lens, holography, near field recording, etc.
• optical storage devices e.g., compact disk (CD), DVD, BD,
• HD-DVD high definition digital versatile disk
• a home or office of company keeps several tens to hundreds of optical storage disks containing various contents.
• FIG. 1 is a block diagram of a structure of a related art optical disk drive.
• the related art optical disk drive includes an optical disk 21, a pick-up unit 11, a servo unit 12, a signal processing unit 14, a memory 15, and a micom 13.
• the optical disk 21 is a recording medium on which data are recorded, reproduced, and erased by a laser.
• the pick-up unit 11 records/reproduces management information including data recorded on the optical disk 21.
• the servo unit 12 controls operations of the pick-up unit 11.
• the signal processing unit 14 demodulates a reproduction signal received from the pick-up unit 11 into a desired signal value, or modulates a signal to be recorded into a signal having a form necessary for performing a recording operation on the optical disk 21 to transmit the signal.
• the memory 15 stores various information necessary for reproducing the optical disk 21.
• the micom 13 controls operations of the above components.
• the components form a recording/reproducing unit 10.
• the pick-up unit 11 includes a laser light source such as a laser diode, a collimator lens, an objective lens driven by a focus actuator or a tracking actuator, a polarized be am splitter, an optical component such as a cylindrical lens, a photodetector converting light into an electrical signal, and a front monitor diode monitoring a laser output during a recording or reproducing operation.
• a laser light source such as a laser diode, a collimator lens, an objective lens driven by a focus actuator or a tracking actuator, a polarized be am splitter, an optical component such as a cylindrical lens, a photodetector converting light into an electrical signal, and a front monitor diode monitoring a laser output during a recording or reproducing operation.
• the micom 13 detects reflected light from the optical disk 21, and calculates an amount of the reflected light through the detected reflected light to generate a radio frequency (RF) signal representing a total sum of the reflected light with respect to each area of photodiodes. Additionally, the micom 13 generates a focus error signal (FES), which is a signal detecting an out-of-focus laser illuminated by the pick-up unit 11 through an astigmatism method. Additionally, the micom 13 generates a tracking error signal (TES) detecting an out-of-track laser illuminated by the pick-up unit 11 through a push-pull method.
• RF radio frequency
• the memory 15 stores various information necessary for reproducing the optical disk
• RAM random access memory
• ROM read only memory
• a controller 23 is responsible for controlling entire components.
• a decoder 22 finally decodes output data in response to control of the controller 23 and then provides the decoded data to a user.
• an encoder 24 converts an input signal into a signal of a predetermined format, e.g., a motion picture experts group 2 (MPEG2) transport stream, and then provides the converted signal to the signal processing unit 14 in response to control of the controller 23.
• MPEG2 motion picture experts group 2
• Fig. 1 illustrates components of recording and reproducing units of the related art optical disk drive.
• the optical disk 21, the recording/reproducing unit 10, and the decoder 22 are used.
• the recording/reproducing unit 10, and the decoder 22 are used in response to control of the controller 23.
• optical disk drive reproduces/executes only the contents stored on the optical disk 21, there is an inconvenience that the optical disk 21 should be replaced with a new optical disk when a user intends to execute other contents.
• a method of destroying data includes a method of making scars on the optical disk surface by using a sharp probe and a method of scratching and destructing a dye area on a recording layer.
• pollution problem due to the dyes occurs, and also data recovery is possible because the scratch itself may not completely erase the data on the optical disk. Disclosure of Invention Technical Problem
• Embodiments provide a method of permanently erasing data recorded on a write- once or rewritable optical disk to be irreversible and an optical disk drive using the same.
• an erase application performing data erasure is executed in an optical disk drive, and also is performed through an optical disk drive including an optical disk emulation.
• a method of erasing data of an optical disk in an optical disk drive including a data erase application through an optical disk emulation includes: receiving an erase command of data recorded on an optical disk; determining whether the optical disk is a rewritable optical disk or not; raising an output power of a laser to be projected when the optical disk is the rewritable optical disk; and erasing the data recorded on the optical disk through an output power of the laser.
• the erasing of the data recorded on the optical disk through the output of the laser may include: performing an overwrite operation on an area of the recorded data through a laser higher than an write power, or destroying boundaries of lands and grooves.
• the method may further include performing an overwrite operation on at least a lead- in area and a file system area.
• the optical disk may include the lead-in area, a user data area, and a lead-out area, the user data area including the file system area where file system data are recorded.
• an optical disk drive includes: an optical disk storage unit recording or reproducing contents through an optical disk; a contents memory unit storing a data erase application therein, and operating as a virtual optical disk when the optical disk is not inserted; a disk type determination unit whether the optical disk is a rewritable or write-once optical disk; a laser power adjustor adjusting an output power of a laser to erase data of the optical disk; a pick-up unit performing an overwrite operation on the optical disk or destroying boundaries of lands and grooves; and a controller allowing the contents memory unit as a virtual optical disk, receiving an erase command of data recorded on the optical disk to load the data erase application, and controlling data erasure of the optical disk.
• the contents memory unit may include a data format identical to that of the optical disk.
• the laser power adjustor may adjust an output power of a laser to more than a write power when the optical disk is a rewritable optical disk, and may adjust the output power of the laser to a write power or an erase power when the optical disk is a write-once optical disk.
• FIG. 1 is a block diagram of a related art optical disk drive.
• Fig. 2 is a block diagram of a structure of an optical disk drive according to one embodiment.
• Fig. 3 is a flowchart illustrating processes until an erase application starts according to one embodiment.
• Fig. 4 is a flowchart illustrating erasing processes after an erase application starts according to one embodiment.
• Fig. 5 is a schematic view of a method of erasing data through weakening of a wobble signal.
• FIG. 2 is a block diagram of a structure of an optical disk drive 100 according to one embodiment.
• An optical disk drive 100 with an optical disk includes an optical disk storage unit
• the optical disk storage unit 110 stores or reproduces contents through the optical disk.
• the contents memory unit 120 stores a data erase application therein and is executed as a virtual optical disk when there is no optical disk.
• the disk type determination unit 140 determines whether the optical disk is a rewritable or write-once optical disk.
• the laser power adjustor 150 adjusts an output power of a laser to erase data of the optical disk.
• the pick-up unit 160 overwrites data on the optical disk or destroys the boundaries of lands and grooves.
• the controller 130 allows the contents memory unit 120 to operate as a virtual optical disk, receives an erase command for erasing data recorded on the optical disk, loads the data erase application, and erases data of the optical disk.
• the controller 130 controls the optical disk storage unit 110 and the contents memory unit 120. Additionally, the controller 130 executes an optical disk process command of a host and returns it to the host, and also controls the contents memory unit 120 to operate as a virtual optical disk.
• the controller 130 copies a file system of the optical disk and applies it to the contents memory unit 120, and also controls the contents memory unit 120 through the optical disk process command. Therefore, the contents memory unit 120 can be emulated as the virtual optical disk.
• the optical disk drive 100 may further include an optical disk determination unit (not shown) determining whether an optical disk is inserted or not when there is an optical disk process command of a host.
• the contents memory unit 120 may include an additional memory such as a random access memory (RAM), a read only memory (ROM), or a free space of an internal memory in an optical disk drive.
• RAM random access memory
• ROM read only memory
• the contents memory unit 120 stores various applications such as an erase application.
• the erase application is a collection of programs for destroying or erasing data recorded on the optical disk and includes an erase engine capable of interpreting, controlling, and determining an optical disk.
• a user can access the optical disk drive 100 through a PC interface, and is configured to use the optical disk drive 100 through an interface connection unit.
• the controller 130 controls the optical disk storage unit 110 and the contents memory unit 120 when receiving a command of a host.
• the controller 130 determines whether an optical disk is inserted into the optical disk drive 100 or not according to the optical disk determination unit.
• the controller 130 controls the contents memory unit 120 to allow the contents memory unit 120 to operate as a virtual optical disk in response to a command from the host, and then returns the result to the host.
• the contents memory unit 120 may operate pretending as an optical disk by adding properties of the optical disk to the contents memory unit 120 even if there is no optical disk in the optical disk drive 100.
• a file system managing an optical disk file needs to identically applied to the contents memory unit 120, and also commands processing the optical disk need to be identically applied to the contents memory unit 120.
• a disk property whether the optical disk is a ROM type or R/RW type
• disk size whether the optical disk is a ROM type or R/RW type
• disk detail specifications a track and session information
• read/write information etc.
• the file system of the optical disk includes ISO09660, a universal disk format (UDF), and UDF-bridge, etc.
• the file system can be divided into a file system area and a file data area.
• the file system area includes a disk model name, disk size, and a pointer pointing position of data.
• the predetermined disk mode name is displaye d to a user through a task manager.
• optical disk process commands need to be identically applied to the contents memory unit 120, and the optical disk process commands may include an advanced technology attachment packet interface (ATAPI).
• ATAPI advanced technology attachment packet interface
• the ATAPI allows the contents memory unit 120 to be emulated as a virtual optical disk through a "Get Configuration” command, a "Test Unit Ready” command, or a "Read Capacity” command.
• applying a file system to the contents memory unit 120 can be done by copying information of the file system of the optical disk as it is and applying it, or compressing information of the file system of the optical disk and applying it.
• a method of compressing information may vary.
• the file system can be copied using a small amount of a memory by not extracting blocks filled with '0' in a file system area.
• the blocks filed with '0' are not extracted and position information is updated through an address shift in order to compress the file system.
• a shift distance is reduced during address mapping, such that management can be easily performed.
• the erase engine executing the erase application is included in the optical disk drive 100 not the host, the erase application is loaded into the PC when the erase application is executed, and the host calls the erase engine and receives a notice of whether to erase or not.
• the disk type determination unit 140 determines whether a type of a disk to be erased is rewritable or not.
• a method of determining a type of a disk is various.
• a type of an optical disk can be determined using a physical property in which respectively different types of optical disks has a different reflectivity.
• the laser power adjuster 150 raises an output power of a laser to be projected, which is higher than a write power.
• the pick-up unit 160 performs an overwrite operation on a recording layer of the optical disk 101 or destroys boundaries between lands and grooves through a laser power higher than the write power.
• the laser power adjuster 150 adjusts an output of the projected laser to the write power or the erase power.
• the pick-up unit 160 performs an overwrite operation on a recording layer of the optical disk 101 or destroys boundaries between lands and grooves of the optical disk 101 through a laser power equal to the write power or the erase power.
• an erase mode when erasing data on the optical disk 101, an erase mode can be additionally set.
• the erase mode includes a quick mode destroying an important area of the optical disk and a full mode destroying the entire area of the optical disk.
• the quick mode minimally destroys the important area of the optical disk such that a user cannot recover the optical disk.
• a lead-in area and a file system area constituting the recording layer of the optical disk are destroyed.
• a process for confirming whether the data is properly destroyed or not may be further included, and this can be done by a fact that an optical pick-up is not properly performed along a track of the optical disk after the data is destroyed.
• the full mode erases the entire area of the optical disk such that a user and an expert cannot recover the optical disk.
• the entire recording layer i.e., the lead-in area, the file system area, a lead-out area, and an entire data area are destroyed. In the full mode, destruction can be confirmed on all the destroyed area.
• the optical disk drive 100 further includes an additional button part, and a user can select data destruction finally. Accordingly, when a data erase operation is set to begin when the user gives a command to erase the optical disk through the button part, reliability for an erase operation can be improved.
• a confirm window can be displayed to finally confirm whether the disk erase operation starts or not.
• the performing of the erase application through a vertical optical disk can be done regardless of operating system (OS), and a virtual disk in a drive can be read for an erase operation in any devices.
• OS operating system
• FIG. 3 is a flowchart illustrating processes until an erase application starts according to one embodiment.
• a method of erasing data includes permanently erasing data through an erase application using a virtual disk. The method is performed by using an erase engine in an optical disk drive.
• an optical disk determination unit determines whether an optical disk is inserted into an optical disk drive or not in operation S205. When the optical disk is not inserted according to the determination result, a virtualization (emulation) process begins according to an embodiment.
• the controller emulates the contents memory unit in operation S210, and selects an erase application stored in the contents memory unit for execution in operation S215 or the erase application is automatically executed. At this point, when the erase application is executed, it automatically recognizes a disk to be erased to select its own optical disk drive for an erase operation.
• the erase application is loaded into a host PC in operation S220, and the host PC opens a tray of the optical disk drive in order to insert a disk of which data will be erased.
• a data erase process begins in operation S235.
• the optical disk determination unit determines that the optical disk is inserted in the optical disk drive, the interested optical disk is displayed in operation S240.
• FIG. 4 is a flowchart illustrating erasing processes after an erase application starts according to one embodiment.
• the disk type determination unit determines whether an optical disk inserted by a user is rewritable or not. As described above, a type of an optical disk can be determined using a physical property in which respectively different types of optical disks has a different reflectivity.
• an output power of a laser is increased in operation S310. More specifically, the laser power adjuster raises a laser power more than a write power.
• the disk type determination unit determines the optical disk is not rewritable, it is determined whether the optical disk is a write-once optical disk or not in operation S315.
• the laser power adjuster adjusts the laser power to the write power or the erase power.
• FIG. 5 is a schematic view of a method of erasing data through weakening of a wobble signal.

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Citations (4)

• 2008
  • 2008-01-21 WO PCT/KR2008/000360 patent/WO2009064038A1/en active Application Filing
  • 2008-01-21 CN CN200880113911A patent/CN101842838A/zh active Pending

Patent Citations (4)

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