Abstract:
A disk recording medium is provided with a wobbled pregroove on which an ATIP signal is recorded, the signal including disk-compatibility information such as linear velocity information when recording. A disk drive apparatus reproduces the linear velocity information when loading the medium and acquires the linear velocity information with system controller. When receiving a data write command form host computer, the controller tells the host computer to prevent data from being recorded on the medium when the linear velocity information acquired from the medium fails to correspond to a recording velocity specified by the host computer. This avoids recording the data at a normal velocity, for example, on the eight-fold acceleration velocity disk medium so that no failure such as an error in recording and a crash of recording layer can occur.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention generally relates to a disk recording medium and a disk drive apparatus preferably being applicable to a medium such as Compact Disk-Recordable (CD-R) and Compact Disk-Rewritable (CD-RW). More specifically, this invention relates to a disk recording medium, which can be correctly handled on the basis of disk-compatibility information recorded on it, and a disk drive apparatus for driving such the disk recording medium.  
           [0003]    2. Description of the Related Art  
           [0004]    Disk recording medium such as CD-R and CD-RW may record data. CD-R is a write-once optical disk using dyed color organic material as recording layer and is compatible with Compact Disk medium (CD). CD-RW is an optical disk allowing data to be written thereon or to be erased therefrom with making a phase change of recording layer in use.  
           [0005]    It has been considered to increase a liner velocity, when recording the data on these disks recording media, in order to accelerate their writing time. In a case of the above CD-RW, since its recording layer comprises phase changeable layer for implementing the writing and erasure of data, characteristics of the phase changeable layer necessary to write the data effectively vary according to the liner velocity when recording. When the liner velocity is increased, CD-RW for slow storage (slow CD-RW) having a recording layer for slow storage is unavailable. This brings about changes that CD-RW for fast storage (fast CD-RW) having a recording layer for fast storage is available in this case.  
           [0006]    If such the fast CD-RW is so constructed that its pregroove can be made like the same of the slow CD-RW to reduce their differences, with taking its disk-compatibility in consideration, it is impossible to distinguish one from another. Under this condition, when the fast CD-RW is erroneously loaded onto a CD-RW drive apparatus for the slow CD-RW, the apparatus may slowly writes the data on the fast CD-RW. This causes the apparatus to fail to write the data in it and results in failure such as crash of recording layer. The same goes for the above CD-R case.  
           [0007]    Accordingly, this invention solves these problems of the related art and an object of the invention is to provide a disk recording medium and so on allowing its correct handling due to its disk-compatibility information.  
         SUMMARY OF THE INVENTION  
         [0008]    According to a first aspect of the invention, we provide a disk recording medium including a pregroove on which control information is recorded. The information comprises disk-compatibility information.  
           [0009]    According to a second aspect of the invention, we also provide a disk recording medium including subcode data. The subcode data comprises disk-compatibility information.  
           [0010]    Further, according to a third aspect of the invention, we also provide a disk drive apparatus for driving a disk recording medium on which disk-compatibility information is recorded. The apparatus comprises reproducing part for reproducing the disk-compatibility information from the disk recording medium and control part for controlling handling of the disk recording medium on the basis of the reproduced disk-compatibility information.  
           [0011]    According to an embodiment of this invention, the disk recording medium may store disk-compatibility information. For example, the medium stores control information including the disk-compatibility information along a pregroove. Alternatively, it may store subcode data including the disk-compatibility information.  
           [0012]    Such the control information storage on the pregroove may be illustratively carried out by Bi-phase modulating the control information and wobbling the pregroove in response to signals obtained from frequency-modulation of thus Bi-phase modulated information. For example, the control information including the disk-compatibility information may be stored on the pregroove in a lead-in area of the medium. The subcode data including the disk-compatibility information may be stored on pre-pits in a lead-in area of the medium.  
           [0013]    According to another embodiment of this invention, the disk drive apparatus may reproduce the disk-compatibility information from the medium so that the medium can be correctly handled on the basis of the disk-compatibility information. When the apparatus determines that the medium would be unavailable for handling, based on the disk-compatibility information, it stores and reproduces no data on and from the medium.  
           [0014]    Thus, this avoids writing the data on the fast CD-RW when it is erroneously loaded onto the slow CD-RW drive apparatus, thereby preventing failure such as an error in data recording and a crash of its recording layer from occurring.  
           [0015]    A further understanding of the nature and advantages of the invention may be realized by reference to the following portions of the specification and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a block diagram showing a constitution of CD-RW drive apparatus as a preferred embodiment of the invention;  
         [0017]    [0017]FIG. 2 is a diagram illustrating a wobbled pregroove in a CD-RW disk medium;  
         [0018]    [0018]FIG. 3 is a diagram illustrating a cross-sectional view of a portion of the CD-RW disk medium;  
         [0019]    [0019]FIG. 4 is a diagram showing a layout of recording areas in the CD-RW disk medium;  
         [0020]    [0020]FIG. 5 is a diagram illustrating a format of an ATIP frame;  
         [0021]    [0021]FIG. 6 is a diagram illustrating encoding embodiment of ATIP frame within a lead-in area as shown in FIG. 4;  
         [0022]    [0022]FIG. 7 is a diagram illustrating bits structure of supplement information as shown in FIG. 6;  
         [0023]    [0023]FIG. 8 is a diagram illustrating a data format of subcode-Q; and  
         [0024]    [0024]FIG. 9 is a diagram illustrating a data format of subcode-Q mode  1  within a lead-in area. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    Referring the drawings, a CD-RW drive apparatus and a CD-RW disk medium as a preferred embodiment of the invention will be explained more in detail.  
         [0026]    Referring to FIG. 1, the CD-RW drive apparatus will be explained and referring to FIGS. 2 through 9, the CD-RW disk medium will be explained.  
         [0027]    [0027]FIG. 1 shows a constitution of the CD-RW drive apparatus  100  for driving the CD-RW disk medium  101 .  
         [0028]    The CD-RW disk medium  101  includes a tight spiral pregroove  150  on its recording layer, which is used as a guide track to write and reproduce data. This pregroove  150  having 1.6 μm track pitch is slightly wobbled in a radial way, as shown in FIG. 2, to control a speed of a motor turning the disk using pregroove&#39;s position information so that area of the disk under a write or read head is always moving at the same speed. Namely, the data is written or reproduced on or from the disk medium at a constant linear velocity using the pregroove. Such the pregroove is called as an “Absolute Time In Pregroove” (ATIP), which is come up with as address information used for a medium with a relatively long data unit such as CD. Time information stored on the ATIP is the same as the one stored on subcode-Q channel of playback-only CD.  
         [0029]    This ATIP includes synchronizing signal for rotating servo when recording and various control signals other than the above address information when recording. The control signals recorded on the ATIP includes a signal indicating the longest writable time between a start time of lead-in and a start time of lead-out when making program length longest, and a signal indicating the most suitable power of recording laser and a type of disk.  
         [0030]    In the CD-RW disk medium, as shown in FIG. 3, multilayer including dielectric layer (ZnS, SiO 2 )  152 , recording layer (Ag—In—Sb—Te)  153 , dielectric layer (ZnS, Sio 2 )  154 , reflectance layer (Al)  155 , UV hardened protective layer (UV-resin) and a label layer  157  is formed on Polycarbonate substrate  151  in which the pregroove is cut, from its bottom to its top.  
         [0031]    When laser irradiates a light beam to the bottom of the disk medium, it causes the recording layer sandwiched between the dielectric layers  152  and  154  to be phase changed depending on the intensity of the recording laser beam. Then, if the recording layer is rapidly melted and cooled, it may become amorphous state while if the layer is gradually heated to the melting point and cooled, it may become crystalline state. The chemical change of material in the recording layer to amorphous state produces a light absorbing state (low reflectivity) while the change to crystalline state produces a reflective state (high reflectivity).  
         [0032]    When recording the data on the disk medium using the above phase change technology, we can use crystalline changed portions in the recording layer as pits so that a signal like the one using for a playback-only CD may be reproduced. The material of the recording layer  153  is selected among the ones to be used according to a type of the disk such as fast-recording disk and a slow-recording disk to allow the disk to be adapted for a linear velocity when recording following their usage.  
         [0033]    Even when CD-R disk medium, not shown, is used, its layer arrangement is generally the same as the above CD-RW disk medium except that the dielectric layers  152  and  154  and recording layer  153  are placed with a recording layer of dye made from photosensitive organic compounds; and a reflectance layer of the CD-R is made from Ag, not A 1 .  
         [0034]    The laser beam having high-energy actually melts the above organic dye by its heat to create pits (troughs). This allows another laser beam to read them as data after recording the data so that a signal like the one for the playback-only CD including the pits on its substrate may be reproduced.  
         [0035]    [0035]FIG. 4 shows a layout of recording areas of the CD-RW disk medium  101 . Arranged are some recording areas such as power calibration area (PCA), program memory area (PMA), lead-in area (LEAD-IN), program area (PROGRAM AREA), and lead-out area (LEAD-OUT), along the direction from a disk center to a disk rim.  
         [0036]    The PCA is used for calibrating power of recording laser. The drive apparatus  100  performs a test write of sectors in this PCA area with several different laser power values based on the recommended power, then reads the test sectors back and selects the laser power that produced the sector with the best reflectivity, before recording user&#39;s data.  
         [0037]    The PMA is used for temporarily storing information about the data recorded on the PROGRAM AREA. The LEAD-IN is used for temporarily containing information of a table of contents (TOC) such as track numbers and their starting and stopping points when tracks are written in a session which is not closed. When the session is closed, the same TOC information is written on this LEAD-IN.  
         [0038]    The PROGRAM AREA is used for storing user&#39;s data. The LEAD-OUT is used for indicating that end of recording area has been reached.  
         [0039]    [0039]FIG. 5 illustrates a format of an ATIP frame. A signal having such the ATIP frame is base-band modulated in Bi-Phase modulation system, then frequency modulated. A manufacturer makes the pregroove  150  on the disk medium  101  when mastering so that it is radially wobbled on the basis of thus modulated signal. This frame has the same period as the subcode used in CD-ROM has. When we read the signal in real time, we calculate that the period used for a standard velocity disk will be 75 Hz and thus, for example, the one used for eight-fold acceleration velocity disk will be 8×75 Hz. In doing so, carrier frequency in the frequency modulation used for the standard velocity disk is calculated to be 22.05 kHz. The carrier frequency for the eight-fold acceleration velocity disk is calculated to be 8×22.05 kHz.  
         [0040]    [0040]FIG. 6 shows an encoding embodiment of the ATIP frame within the LEAD-IN. The ATIP frame includes some areas for special information, additional information, and supplement information in addition to the areas for normal address information. These areas for the special information, the additional information, and the supplement information may store the above information such as the start times of lead-in and lead-out, the most suitable power of recording laser and the type of disk. In this embodiment, the supplement information area stores the linear velocity information as disk-compatibility information. The linear velocity information includes information indicating a recording linear velocity at which the disk  101  is available.  
         [0041]    [0041]FIG. 7 shows a bits structure of the supplement information. Two bits of M 7 -M 6 , [Bv 1 , Bv 2 ] represent linear velocity information of the disk. Four bits of M 23 -M 20 , [ 0011 ], represent the supplement information. Twelve bits of M 19 -M 8 , [F 1 , F 2 , . . . . , F 11 , F 12 ] are reserved for future extension. Three bits of M 5 -M 3 , [J 1 , J 2 , J 3 ] represent inertia information. Two bits of M 2 -M 1 , [Dm 1 , Dm 2 ] represent information on diameter of the disk. One bit of MO, [S 1 ] represents recording density information of the disk.  
         [0042]    [0042]FIG. 8 shows a data format (a format of frame) of subcode-Q channel recorded on the disk  101 . This format of frame comprises control data of four bits, address data of four bits, data (data-Q) of 72 bits and cyclic redundancy check codes (CRC) of 16 bits. In this embodiment, when writing the subcode in the lead-in area of the disk  101 , the linear velocity information recorded on the ATIP as the disk-compatibility information as described above may be written on subcode-Q mode  1 .  
         [0043]    [0043]FIG. 9 shows a data format of the subcode-Q mode  1  within the lead-in area. In this case, address data, 1 h (“h” indicates hexadecimal number, hereinafter the letter, h, will be used in a like manner) represents the mode  1 . TNO, 00h represents the lead-in area. In this data format, as POINT represents F0h, the linear velocity information is set on PMIN.  
         [0044]    Referring back to FIG. 1, the drive apparatus  100  comprises a spindle motor  102  for rotating the above disk medium  101  in a constant linear velocity. In an embodiment according to the invention, the drive apparatus  100  performs the operation to write and reproduce data on and from the disk in a standard velocity or an eight-fold acceleration velocity.  
         [0045]    The drive apparatus  100  also comprises an optical pick-up  103  having a semiconductor laser, an objective lens, and a plurality of photo detectors, a laser driver  104  for controlling emission of the semiconductor laser of optical pick-up  103 , and RF amplifier  105  for processing output signals from the photo detectors included in the optical pick-up  103  to produce a reproduced RF signal, SRF, a tracking error signal, ET, a focusing error signal, SF, and a wobble signal SWB which corresponds to the wobbling of pregroove  150 .  
         [0046]    The recording layer of the disk medium  101  is irradiated with laser beam (not shown) from the semiconductor laser of optical pick-up  103  and then, a plurality of photo detectors of the optical pick-up  103  such as 6-split photo detector is irradiated with its reflected light. The RF amplifier  105  produces the tracking error signal E T  using an appropriate method such as differential push pull (PDD) method and the focusing error signal EF using an appropriate method such as astigmatic method.  
         [0047]    Further, the drive apparatus  100  comprises an RF signal processing circuit  106  for performing a process such as waveform equalization and signal detection against the reproduced RF signals, S RF  received from the RF amplifier  105  to produce CD data, and a recording compensation circuit  107  for compensating record data RD received from a CD encoder/decoder  111 , which is described later, to transfer thus compensated record data RD to the laser driver  104 . Laser beam irradiated from the semiconductor laser of optical pick-up  103  is modulated with thus compensated record data RD, thereby allowing it to be recorded on the disk medium  101  using the above phase change technology.  
         [0048]    Additionally, the drive apparatus  100  comprises the CD encoder/decoder  111  and a CD-ROM encoder/decoder  112 . When reproducing, the CD encoder/decoder  111  produces CD-ROM data by demodulating the CD data received from the RF signal processing circuit  106  due to an eight to fourteen modulation (EFM) and carrying out a cross-interleaved Reed-Solomon code (CIRC) error correction processing against the CD data.  
         [0049]    When recording, the CD encoder/decoder  111  produces the record data RD by performing a non-return to zero-inverted (NRZI) conversion processing against the CD data obtained by adding parity to CD-ROM data received from the CD-ROM encoder/decoder  112  based on the CIRC, and modulating the CD-ROM data due to the EFM.  
         [0050]    When reproducing, the CD-ROM encoder/decoder  112  produces read data by de-scrambling and error-correcting the CD-ROM data received from the CD encoder/decoder  111 .  
         [0051]    When recording, the CD-ROM encoder/decoder  112  produces a CD-ROM data by adding parity for error correction to write data received from a small computer system interface (SCSI)/buffer controller  115 , which will be described later more in detail, and scrambling it. This CD-ROM encoder/decoder  112  is connected with a random access memory (RAM)  113  as a work memory for performing the above processes.  
         [0052]    Further, the drive apparatus  100  comprises the SCSI/buffer controller  115 . The controller  115  receives commands from host computer and transfers them to a system controller  125  having central processing unit(s) (CPU) for controlling the operations of the whole system. When reproducing, the controller  115  transfers the read data received from the CD-ROM encoder/decoder  112  to the host computer through RAM  114  as a buffer memory. When recording, it transfers the write data received from the host computer to the CD-ROM encoder/decoder  112  through RAM  114 .  
         [0053]    The drive apparatus  100  comprises a focus/tracking servo controller  121 , a slide servo controller  122  and a spindle servo controller  123 . The focus/tracking servo controller  121  controls the optical pick-up  103  so that it may be focused and tracked in response to focusing error signal E F  and the tracking error signal E T  received from the RF amplifier  105 . The slide servo controller  122  controls the optical pick-up  103  so that it may be slid when accessed. The spindle servo controller  123  controls the spindle motor  102  SO that it may rotate at an appropriate number of revolutions. A mechanical controller  124  having CPU controls the operations of these servo controllers  121  through  123 .  
         [0054]    The drive apparatus  100  comprises a wobble processor  131  for decoding ATIP signals in response to the wobble signals SWB received from the RF amplifier  105 . The processor  131  transfers thus decoded ATIP signals to the mechanical and system controllers  124  and  125  through the CD encoder/decoder  111  whereby these signals are used for various controls.  
         [0055]    Operations of the CD-RW drive apparatus  100  as shown in FIG. 1 will be described.  
         [0056]    When the host computer transfers a data write command to the system controller  125 , the drive apparatus  100  starts writing or recording data on the disk medium  101 . Since the apparatus  100  can write the data at a standard velocity or eight-fold accelerated one, as described above, the host computer transfers information about an indication of disk recording speed to the apparatus  100  in addition to the above data write command.  
         [0057]    When the disk medium (CD-RW disk)  101  is loaded onto the drive apparatus  100 , the apparatus reads the stored data from the lead-in area of the disk medium  101  to acquire ATIP signals. Thus, the system controller  125  may also acquire the linear velocity information as the disk-compatibility information set in the supplement information area in the lead-in area. If thus acquired linear velocity fails to correspond to the disk recording speed indicated by the host computer, the system controller  125  tell the host computer that it is impossible to write.  
         [0058]    If the acquired linear velocity corresponds to the disk recording speed, the controller  125  starts writing the data. The controller  125  controls the revolution of disk medium  101  so that the data may be written on it at an appropriate linear velocity corresponding to the indicated disk recording speed. The SCSI/buffer controller  115  receives the write data from the host computer and transfers it to the CD-ROM encoder/decoder  112 . The CD-ROM encoder/decoder  112  adds parity for error correction to the write data and scrambles it to produce CD-ROM data.  
         [0059]    The CD encoder/decoder  111  receives thus produced CD-ROM data from the CD-ROM encoder/decoder  112 . The CD encoder/decoder  111  adds parity under CIRC to the CD-ROM data and modulates it due to the EFM to produce the CD data and then, performs NRZI conversion against the CD data to produce the record data RD.  
         [0060]    The recording compensation circuit  107  compensates the record data RD and transfers it to the laser driver  104 . The semiconductor laser of the optical pick-up  103  irradiates the laser beam modulated in response to thus compensated recording data RD to the disk medium  101  wherein phase change occurs in response to the record data RD and the record data RD is written on the disk medium  101 .  
         [0061]    After the apparatus  100  quits writing the data from the host computer on the disk medium  101 , it also writes subcode on the lead-in area of the disk medium  101 . In this case, the linear velocity information as the disk-compatibility information recorded on the ATIP as described above is written on the lead-in area as subcode-Q model  1 .  
         [0062]    When the host computer transfers a data read command to the system controller  125 , the drive apparatus  100  starts reading or reproducing data from the disk medium  101 . Since the apparatus  100  can write the data at a standard velocity or eight-fold accelerated one as described above, the host computer transfers information about an indication of disk reproducing speed to the apparatus  100  in addition to the above data read command. The controller  125  controls the revolution of disk medium  101  so that the data may be read from the disk medium  101  at an appropriate linear velocity corresponding to the indicated disk reproducing speed.  
         [0063]    The pick-up  103  reproduces the reproduced RF signal. The RF signal processing circuit  106  performs a process such as waveform equalization against the reproduced RF signal to produce CD data. The CD encoder/decoder  111  receives thus produced CD data from the RF signal processing circuit  106 . The CD encoder/decoder  11  performs the EFM demodulation against the produced CD data and adds parity for error correction under CIRC to it to produce the CD-ROM data.  
         [0064]    The CD-ROM encoder/decoder  112  receives thus produced CD-ROM data from the CD encoder/decoder  111  and descrambles and error corrects it to produce the read data. This read data is timely transferred to the host computer through the RAM  114  as the buffer memory under the control of the SCSI/buffer controller  115 .  
         [0065]    Thus, according to an embodiment of the invention, since the linear velocity information as the disk-compatibility information is stored in the supplement information area as the ATIP signals recorded in the pregroove  150  of the lead-in area of the disk medium (CD-RW disk)  101 , system controller  125  can acquire this linear velocity information when the disk medium  101  is loaded onto the apparatus  100 . If thus acquired linear velocity fails to correspond to the disk recording speed indicated by the host computer, the system controller  125  tell the host computer that it is impossible to write, thereby stopping writing the data on the disk medium  101 . This avoids writing the data either on the standard velocity disk medium at eight-fold accelerated velocity or on the eight-fold accelerated velocity disk medium at standard velocity when these disk media are erroneously loaded onto the apparatus  100 . Therefore, it prevents a failed storage and a recording layer crash from occurring.  
         [0066]    According to another embodiment of the invention, after the apparatus  100  quits writing the data from the host computer on the disk medium  101 , it writes subcode on the lead-in area. In this case, the linear velocity information as the disk-compatibility information stored on the ATIP is written as subcode-Q model  1 , as described above. When thus recorded disk medium  101  is loaded onto a playback-only drive apparatus, the linear velocity information can be acquired from the subcode data reproduced from the lead-in area. Based on this linear velocity information, various reproducing processes such as waveform equalization can be performed.  
         [0067]    Although, according to the above embodiments, the linear velocity information as the disk-compatibility information is stored in the supplement information area, it may be stored on other portion of the pregroove.  
         [0068]    Although, according to the above embodiments, the invention is applied to CD-RW disk medium  101  and CD-RW drive apparatus  100 , it may be also applied to other disk recording medium and/or a disk drive apparatus such as CD-R disk medium and CD-R drive apparatus.  
         [0069]    Although, according to the above embodiments, the linear velocity information is used as the disk-compatibility information, other information about the disk-compatibility such as recording system information may be also used.  
         [0070]    Particularly, when a playback-only disk recording medium is applied, disk-compatibility information may be stored on subcode data recorded using pre-pits in its lead-in area.  
         [0071]    While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents thereof may be used. Therefore, the above description should not be taken as limiting the scope of the invention as defined by the appended claims.