Abstract:
A method, apparatus and computer-readable recording medium are disclosed, for recording information in an information recording medium. The method includes a first step of outputting, in response to an initialization request for initializing the information recording medium, termination information indicative of termination of the initialization before the initialization starts, and a second step of starting the initialization at a predetermined timing after the output of the termination information. In this procedure, it is possible to start to record data in a blank disc sooner than in conventional methods.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to a method of recording information in an information recording medium, an apparatus to implement the method, and a computer-readable recording medium for storing a program to cause a computer to implement the method.  
           [0003]    2. Description of the Related Art  
           [0004]    Recent functional improvements in personal computers (PC) make it possible to deal more easily with audio and visual information such as music and images. Emergence of personal computers that incorporate a receiver for receiving TV programs or radio programs accelerates developments of optical discs, such as a DVD+R (Digital Versatile Disc+Recordable) and a DVD+RW (Digital Versatile Disc+ReWritable), suitable for storing a large amount of broadcast content information. As such an optical disc is now more affordable, an optical disc apparatus, which serves as an information recorder for the optical disc, is more widely used. In addition, each of a DVD+R and a DVD+RW is compatibile with a currently widespread DVD-ROM (Digital Versatile Disc+Read Only Memory). In other words, a conventional DVD-ROM drive apparatus can properly reproduce information recorded in a DVD+R and a DVD+RW.  
           [0005]    In order to establish this compatibility with a DVD-ROM, in particular, a DVD+RW has to be formatted to record dummy data in advance in the entire recorded area or a designated portion thereof. In general, it takes a long processing time to complete this formatting process. For this reason, a DVD+RW is conventionally formatted using a background formatting method. In accordance with the background formatting method, when a user requests a formatting process for a DVD+RW, only predetermined management information is recorded in a portion of the lead-in area of the DVD+RW (initialization). Then, the user is informed that the formatting process has been completed, although the entire formatting process has not actually been completed yet, and is allowed to record and reproduce information in the DVD+RW. Then, while the user is not accessing the DVD+RW, dummy data are recorded in the remaining recorded area so as to complete the entire formatting process.  
           [0006]    Japanese Laid-Open Patent Application No. 2001-043663, which was presented by the present inventor, discloses an invention for recording and reproducing an optical disc in an information recording apparatus. In the disclosed apparatus, when a user requests the apparatus to record or reproduce desired information during initialization, the apparatus temporarily halts the initialization and records the information. Accordingly, the apparatus makes it possible to make a newly purchased optical disc (a blank disc) recordable sooner than conventional methods because the apparatus can start to record information without completion of the initialization.  
           [0007]    According to the disclosed apparatus, however, after the user inserts a blank disc into the apparatus so as to record desired data (user data), it is necessary for the user to wait for the time required to record at least predetermined management information in the lead-in area of the optical disc before being allowed to start recording user data. Thus, for example, even if the user attempts to record a currently broadcast TV program in a DVD+RW, the apparatus is not capable of recording the TV program immediately. In this case, there is a risk that the apparatus cannot record a desired portion of the TV program.  
           [0008]    On the other hand, user data are also not allowed to be recorded in a DVD+R until predetermined management information is recorded in a portion of the lead-in area of the DVD+R. Thus, it is necessary for a user to wait for the time required to record at least predetermined management information in a portion of the lead-in area before the user data may start to be recorded. Accordingly, even if the user attempts to record a currently broadcast TV program in a DVD+R, the apparatus is not capable of recording the TV program immediately, as in the above-mentioned DVD+RW. In this case, there is a risk that the apparatus cannot record a desired portion of the TV program.  
         SUMMARY OF THE INVENTION  
         [0009]    It is a general object of the present invention to provide a method and apparatus of recording information in an information recording medium in which one or more of the above-mentioned problems are eliminated.  
           [0010]    A more specific object of the present invention is to provide a method of recording information with a reduced waiting time before user information is allowed to be recorded, an apparatus to implement the method, and a computer-readable recording medium for storing a program to cause a computer to implement the method.  
           [0011]    In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a method of recording information in an information recording medium, the method including: a first step of outputting, in response to an initialization request for initializing the information recording medium, termination information indicative of termination of the initialization before the initialization starts; and a second step of starting the initialization at a predetermined timing after the output of the termination information.  
           [0012]    In an embodiment of the present invention, the initialization may include a formatting process and the predetermined timing may be a receipt time of a format interrupt request of the information recording medium.  
           [0013]    In an embodiment of the present invention, the predetermined timing may be a receipt time of an ejection request of the information recording medium.  
           [0014]    In an embodiment of the present invention, the predetermined timing may be a time at which access to the information recording medium is not requested.  
           [0015]    In an embodiment of the present invention, the method may further include: a third step of creating, in response to an initialization information request for requesting information regarding the initialization before completion of the initialization, provisional information corresponding to the information regarding the initialization and providing the provisional information in response to the initialization information request.  
           [0016]    In an embodiment of the present invention, the method may further include: a fourth step of interrupting the initialization in response to a write request for recording user data in the information recording medium; and a fifth step of restarting the initialization after the user data have been recorded in the information recording medium.  
           [0017]    In an embodiment of the present invention, the second step may record predetermined management information in a lead-in area of the information recording medium.  
           [0018]    In an embodiment of the present invention, the information recording medium may comply with a DVD+RW standard.  
           [0019]    Additionally, there is provided according to another aspect of the present invention a method of recording information in an information recording medium, the method including: a first step of recording, in response to a write request for recording user data in the information recording medium accompanied by recording of management information, the user data before the recording of the management information; and a second step of recording the management information after the user data have been recorded.  
           [0020]    In an embodiment of the present invention, the method may further include: a third step of creating, in response to a management information request for requesting the management information before completion of the recording of the management information, provisional information corresponding to the management information and providing the provisional information in response to the management information request.  
           [0021]    In an embodiment of the present invention, the information recording medium may comply with a DVD+R standard.  
           [0022]    Additionally, there is provided according to another aspect of the present invention an apparatus for recording information in an information recording medium, the apparatus including: a termination information output part, in response to an initialization request for initializing the information recording medium, outputting termination information indicative of termination of the initialization before the initialization starts; and an initialization part starting the initialization by recording predetermined initialization information in a predetermined area in the information recording medium at a predetermined timing after the output of the termination information.  
           [0023]    In an embodiment of the present invention, the initialization request may be issued by an external apparatus.  
           [0024]    In an embodiment of the present invention, the apparatus may further include: a response part, in response to the initialization information request before completion of the initialization, creating provisional information corresponding to the initialization information and providing the provisional information in response to the initialization information request.  
           [0025]    In an embodiment of the present invention, the initialization information request may be issued by an external apparatus.  
           [0026]    In an embodiment of the present invention, the apparatus may further include: an initialization interruption part interrupting the initialization in response to a write request for recording user data in the information recording medium; and an initialization restart part restarting the initialization after the user data have been recorded in the information recording medium.  
           [0027]    In an embodiment of the present invention, the write request may be issued by an external apparatus.  
           [0028]    Additionally, there is provided according to another aspect of the present invention an apparatus for recording information in an information recording medium, the apparatus including: a user data recording part, in response to a write request for recording user data in the information recording medium accompanied by recording of management information, recording the user data before the recording of the management information; and a management information recording part recording the management information after the user data have been recorded.  
           [0029]    In an embodiment of the present invention, the write request may be issued by an external apparatus.  
           [0030]    In an embodiment of the present invention, the apparatus may further include: a response part, in response to a management information request for requesting the management information before completion of the recording of the management information, creating provisional information corresponding to the management information and providing the provisional information in response to the management information request.  
           [0031]    In an embodiment of the present invention, the management information request may be issued by an external apparatus.  
           [0032]    The above-mentioned method and apparatus can be implemented through a program, which is stored in a computer-readable recording medium, to cause a computer to execute a procedure for implementing the method and the apparatus.  
           [0033]    According to one aspect of the present invention, it is possible to reduce a waiting time before user data are allowed to start to be recorded in an information recording medium.  
           [0034]    Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]    [0035]FIG. 1 is a block diagram illustrating a structure of an optical disc apparatus to which a method according to the present invention is applied;  
         [0036]    [0036]FIG. 2 is a diagram for explaining a structure of a recorded area of a DVD+RW;  
         [0037]    [0037]FIG. 3 is a diagram for explaining a structure of a lead-in area of the DVD+RW in FIG. 2;  
         [0038]    [0038]FIG. 4 is a portion of a flowchart of an operation of an optical disc apparatus according to a first embodiment of the present invention in response to receipt of a format request command;  
         [0039]    [0039]FIG. 5 is the remaining portion of the flowchart of the operation of the optical disc apparatus according to the first embodiment of the present invention in response to receipt of a format request command;  
         [0040]    [0040]FIG. 6 is a diagram for explaining a structure of the recorded area in FIG. 2 in a state in which data are recorded during the operation in FIG. 4 and FIG. 5;  
         [0041]    [0041]FIG. 7 is a flowchart of an operation of the optical disc apparatus according to the first embodiment of the present invention in response to receipt a FDCB information request command;  
         [0042]    [0042]FIG. 8 is a flowchart of an operation of an optical disc apparatus according to a second embodiment of the present invention in response to a write request command; and  
         [0043]    [0043]FIG. 9 is a flowchart of an operation of the optical disc apparatus according to the second embodiment of the present invention in response to a SDCB information request command. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0044]    In the following, embodiments of the present invention are described with reference to the accompanying drawings.  
         [0045]    A description will now be given, with reference to FIG. 1 through FIG. 7, of an optical disc apparatus according to a first embodiment of the present invention.  
         [0046]    [0046]FIG. 1 shows a structure of an optical disc apparatus  20 , which serves as an information recorder, according to the first embodiment of the present invention. Referring to FIG. 1, the optical disc apparatus  20  comprises a spindle motor  22  for rotating an optical disc  21 , an optical pickup device  23 , a laser control circuit  24 , an encoder  25 , a motor driver  27 , a reproduction signal processing circuit  28 , a servo controller  33 , a buffer RAM  34 , a buffer manager  37 , an interface  38 , a ROM (Read Only Memory)  39 , a CPU (Central Processing Unit)  40  and a RAM (Random Access Memory)  41 . Here, (solid) connection lines illustrated in FIG. 1 indicate flows of signals and data. It is noted that these connection lines do not represent all connections between components of the optical disc apparatus  20  in FIG. 1. Also, the optical disc apparatus  20  can access an information recording medium in compliance with a DVD+RW standard or a DVD+R standard. In the first embodiment, it is supposed that the optical disc  21  complies with the DVD+RW standard.  
         [0047]    The optical pickup device  23  comprises a semiconductor laser, an optical system, a receiver and a driving system, which are not illustrated. The semiconductor laser serves as an illuminant to emit a laser beam. The optical system guides the laser beam onto the recorded surface of the optical disc  21 . After the laser beam is reflected on the recorded surface, the optical system further guides the reflected laser beam to a predetermined receiving position. The receiver receives the reflected laser beam and generates a signal corresponding to the amount of energy of the received laser beam. Then, the generated signal is supplied to the reproduction signal processing circuit  28 . The driving system comprises a focusing actuator, a tracking actuator and a seek motor, which are not illustrated.  
         [0048]    The reproduction signal processing circuit  28  extracts a wobble signal, an RF signal and a servo signal (a focusing error signal, a tracking error signal and so on) from an output signal of the optical pickup device  23 . In addition, the reproduction signal processing circuit  28  extracts ADIP (Address In Pregroove) information and a synthesizing signal and so on from the wobble signal. The reproduction signal processing circuit  28  supplies the ADIP information and the synthesizing signal to the CPU  40  and the encoder  25 , respectively. After performing a decoding process and an error correction process on the RF signal, the reproduction signal processing circuit  28  stores the resulting signal in the buffer RAM  34  via the buffer manager  37 . Also, the reproduction signal processing circuit  28  supplies the focusing error signal and the tracking error signal to the servo controller  33 .  
         [0049]    The servo controller  33  generates a control signal for controlling the focusing actuator of the optical pickup device  23  based on the focusing error signal. Also, the servo controller  33  generates a control signal for controlling the tracking actuator of the optical pickup device  23  based on the tracking error signal. The servo controller  33  supplies these control signals to the motor driver  27 .  
         [0050]    The buffer manager  37  manages input/output of data to/from the buffer RAM  34 . When the amount of accumulated data reaches a predetermined amount, the buffer manager  37  informs the CPU  40  of this fact.  
         [0051]    The motor driver  27  drives the focusing actuator and the tracking actuator of the optical pickup device  23  based on the control signals from the servo controller  33 . Based on an instruction from the CPU  40 , the motor driver  27  also controls the spindle motor  22  so as to make the linear speed of the optical disc  21  constant. In addition, the motor driver  27  drives the seek motor of the optical pickup device  23  based on an instruction from the CPU  40  so as to adjust the position of the optical pickup device  23  with respect to the sled direction thereof.  
         [0052]    The encoder  25  fetches data to be recorded from the buffer RAM  34  via the buffer manager  37  based on an instruction from the CPU  40 . Then, the encoder  25  performs some processes such as data modulation and attachment of error correction code on the data so as to generate a write signal for the optical disc  21 . The encoder  25  supplies the write signal to the laser control circuit  24  in synch with the synchronizing signal from the reproduction signal processing circuit  28 .  
         [0053]    The laser control circuit  24  controls an output level of the semiconductor laser of the optical pickup device  23  based on the write signal from the encoder  25  and an instruction from the CPU  40 .  
         [0054]    The interface  38  serves as a bidirectional communication interface between the optical disc apparatus  20  and a host such as a personal computer. The interface  38  operates in compliance with a standard interface such as ATAPI (AT Attachment Packet Interface) and SCSI (Small Computer System Interface).  
         [0055]    The ROM  39  maintains a program to be explained below (hereinafter referred to as a first recording control program) described as code executable by the CPU  40 . When the optical disc apparatus  20  is switched ON, the first recording control program in the ROM  39  is loaded into the main memory (not illustrated) of the optical disc apparatus  20 , and the CPU  40  controls the above-mentioned individual components in accordance with the first recording control program and temporarily stores data necessary for the control in the RAM  41 .  
         [0056]    A description will now be given, with reference to FIG. 2 and FIG. 3, of an exemplary structure of the optical disc  21 .  
         [0057]    [0057]FIG. 2 is a diagram illustrating an exemplary recorded area of the optical disc (DVD+RW)  21  in compliance with a DVD+RW standard. Referring to FIG. 2, the recorded area is divided into three areas: a lead-in area (LIA), a data area (DZA) and a lead-out area (LOA), which are ordered from the inner circumferential side to the outer circumferential side. Given user data are recorded in the DZA of the optical disc  21 . In FIG. 2, the track of the optical disc  21  is schematically illustrated as a straight line for convenience although the track is actually provided as a spiral line. The left-hand side in FIG. 2 corresponds to the inner circumferential side of the optical disc  21 , and the right-hand side in FIG. 2 corresponds to the outer circumferential side of the optical disc  21 .  
         [0058]    [0058]FIG. 3 is a diagram illustrating an exemplary LIA of the optical disc (DVD+RW)  21 . Referring to FIG. 3, the LIA occupies the addresses 01D830 through 030000 and comprises 12 zones: an initial zone, an inner disc test zone, an inner drive test zone, a guard zone  1 , a reserved zone  1 , a reserved zone  2 , an inner disc identification zone, a reserved zone  3 , a reference code zone, a buffer zone  1 , a control data zone and a buffer zone  2 . In the inner disc identification zone, a formatting disc control block (FDCB), in which formatting status and data recording status are described in a bitmap manner, is recorded. Also, in the control data zone, physical format information, which includes start address information and end address information of the DZA, is recorded. Here, addresses of the optical disc  21  are described in a hexadecimal form.  
         [0059]    A description will now be given, with reference to FIG. 4 and FIG. 5, of an exemplary operation of the optical disc apparatus  20  in response to receipt of a format unit command, which is for requesting formatting of the optical disc  21 , from the host. When the optical disc apparatus  20  receives the format unit command, the optical disc apparatus  20  sets the head address of a program corresponding to a procedure illustrated in FIG. 4 and FIG. 5 to a program counter of the CPU  40  and starts execution of the program. In this embodiment, it is assumed that a blank disc is used as the optical disc  21 .  
         [0060]    [0060]FIG. 4 and FIG. 5 provide a flowchart of an operation of the optical disc apparatus  20  in response to receipt of a format unit command. Referring to FIG. 4, format completion information, which indicates that the optical disc  21  has been properly formatted, is sent to the host at step S 401 . Accordingly, the optical disc apparatus  20  can currently receive a write request and a read request. At the same time, the optical disc apparatus  20  sets “0”s in a format interrupt request flag, an ejection request flag, a write request flag and a read request flag so as to initialize these flags. Here, the format interrupt request flag is used to indicate whether or not the optical disc apparatus  20  is requested to interrupt formatting of the optical disc  21 . The ejection request flag is used to indicate whether or not the optical disc apparatus  20  is requested to eject the optical disc  21 . The write request flag is used to indicate whether or not the optical disc apparatus  20  is requested to record data in the optical disc  21 . The read request flag is used to indicate whether or not the optical disc apparatus  20  is requested to reproduce data in the optical disc  21 . In this embodiment, the optical disc apparatus  20  communicates with the host in terms of both transmission and receipt in accordance with an interrupt process. In response to receipt of a “close track/session command” as the format interrupt request from the host, the optical disc apparatus  20  sets a “1” to the format interrupt request flag under the interrupt process. In response to receipt of a “start/stop unit command” for the ejection request, the optical disc apparatus sets a “1” to the ejection request flag under the interrupt process. In response to receipt of a “write command” for the write request, the optical disc apparatus  20  sets a “1” to the write request flag under the interrupt process. In response to receipt of a “read command” for the read request, the optical disc apparatus  20  sets a “1” to the read request flag under the interrupt process.  
         [0061]    At step S 403 , the optical disc apparatus waits for a write request. If the optical disc apparatus  20  recognizes that the write request flag is set as “1” with reference to the write request flag (step S 403 : Y), the optical disc apparatus moves to step S 405 .  
         [0062]    At step S 405 , after resetting the write request flag as “0”, the optical disc apparatus  20  records given user data in a designated area in the DZA. The write process of the optical disc apparatus  20  is described in detail below. After recording the user data, the optical disc apparatus  20  moves to step S 407 .  
         [0063]    At step S 407 , the optical disc apparatus  20  starts to record predetermined management information in a portion of the LIA of the optical disc  21  for the purpose of disc initialization of the optical disc  21 . In this disc initialization, the optical disc apparatus  20  records just  16  sectors of the management information at step S 407  and then moves to step S 409 . In disc initialization of a DVD+RW, the predetermined management information is recorded in the addresses 02DC80 through 030000, that is, a guard zone  1 , a reserved zone  1 , a reserved zone  2 , an inner disc identification zone, a reserved zone  3 , a reference code zone, a buffer zone  1 , a control data zone and a buffer zone  2  (FIG. 3).  
         [0064]    At step S 409 , the optical disc apparatus  20  determines whether or not the optical disc apparatus  20  receives a format interrupt request from the host. For this determination, the optical disc apparatus  20  refers to the format interrupt request flag, and if the format interrupt request flag is not set as “1”, the optical disc apparatus determines that the format interrupt is not requested (S 409 : N) and moves to step S 411 .  
         [0065]    At step S 411 , the optical disc apparatus  20  determines whether or not the optical disc apparatus  20  receives an ejection request from the host. For this determination, the optical disc apparatus  20  refers to the ejection request flag, and if the ejection request flag is set as “0”, the optical disc apparatus  20  determines that the ejection is not requested (step S 411 : N) and moves to step S 413 .  
         [0066]    At step S 413 , the optical disc apparatus  20  determines whether or not the optical disc apparatus  20  receives a write request or a read request from the host. For this determination, the optical disc apparatus  20  refers to the write request flag and the read request flag, and if both of them are set as “0”s, the optical disc apparatus  20  determines that the optical disc apparatus  20  has not received the write request or the read request for the optical disc  21  (step S 413 : N) and moves to step S 415 .  
         [0067]    At step S 415 , the optical disc apparatus  20  continues the above-mentioned disc initialization. After completing the recording of another  16  sectors of the predetermined management information, the optical disc apparatus  20  moves to step S 427 .  
         [0068]    At step S 427 , the optical disc apparatus  20  determines whether or not the disc initialization is completed. Namely, it is determined whether or not the predetermined management information is recorded in the addresses 02DC80 through 030000. At step S 427  in the first iteration of steps S 409 , S 411 , S 413 , S 415  and S 427 , just  32  sectors of the predetermined management information are recorded in the optical disc  21 . Thus, it is determined that the disc initialization is not completed at this time, and the optical disc apparatus  20  returns to step S 409 .  
         [0069]    In order to complete the disc initialization, the optical disc apparatus  20  repeats the above-mentioned steps S 409 , S 411 , S 413 , S 415  and S 427  until all of determination steps S 409 , S 411 , S 413  and S 427  are satisfied.  
         [0070]    On the other hand, if the format interrupt request flag is set as “1”, the optical disc apparatus  20  determines that the format interrupt is requested (step S 409 : Y) and moves to step S 431 .  
         [0071]    At step S 431 , the optical disc apparatus  20  attempts to complete the disc initialization. Namely, the optical disc apparatus  20  records the remaining portion of the predetermined management information in a predetermined address. Then, after completion of the disc initialization, the optical disc apparatus  20  moves to step S 433 .  
         [0072]    At step S 433 , the optical disc apparatus  20  performs a format interrupt process. Namely, if there is an unrecorded area between the last written address (LWA), which is the most outer circumferential address of the recorded area being occupied by the user data, and the head address of the DZA, the optical disc apparatus  20  records dummy data in the unrecorded area. In addition, the optical disc apparatus  20  updates the FDCB in the LIA and records a temporary lead-out (TLO) immediately following the LWA as illustrated in FIG. 6. As a result, it is possible to maintain compatibility with a DVD-ROM. After completion of the format interrupt process, the optical disc apparatus  20  terminates the operation that responds to the receipt of the format request command from the host.  
         [0073]    On the other hand, if the ejection request flag is set as “1” at step S 411 , the optical disc apparatus  20  determines that the ejection is requested (step S 411 : Y) and moves to step S 435 .  
         [0074]    At step S 435 , after resetting the ejection request flag as “0”, the optical disc apparatus  20  informs the host of error information so as to prompt the host to issue a format interrupt request and then returns to step S 409 .  
         [0075]    On the other hand, if the write request flag or the read request flag is set as “1” at step S 413 , the optical disc apparatus  20  determines that the optical disc apparatus  20  is requested to perform a recording process or reproducing process for the optical disc  21  (step S 413 : Y) and then moves to step S 417 .  
         [0076]    At step S 417 , the optical disc apparatus  20  interrupts the disc initialization and then moves to step S 419 .  
         [0077]    At step S 419 , the optical disc apparatus  20  refers to the write request flag, and if the write request flag is set as “1”, the optical disc apparatus  20  determines that the optical disc apparatus  20  is requested to record data (step S 419 : Y) and moves to step S 421 .  
         [0078]    At step S 421 , after resetting the write request flag as “0”, the optical disc apparatus  20  records given user data in a designated area in the DZA. After recording the user data, the optical disc apparatus  20  moves to step S 423 .  
         [0079]    On the other hand, if the write request flag is not set as “1”, the optical disc apparatus determines that the optical disc apparatus  20  is not requested to record data (step S 419 : N), that is, the optical disc apparatus  20  determines that the optical disc apparatus  20  is requested to reproduce user data in the optical disc  21 , and then moves to step S 425 .  
         [0080]    At step S 425 , after resetting the read request flag as “0”, the optical disc apparatus  20  reproduces the user data recorded in an area designated by the host and transfers the designated user data to the host. The reproduction process of the optical disc apparatus  20  is described in detail below. After reproducing the designated user data, the optical disc apparatus moves to step S 423 .  
         [0081]    At step S 423 , the optical disc apparatus restarts the disc initialization and moves to step S 427 .  
         [0082]    At step S 427 , if the disc initialization is completed (step S 427 : Y), the optical disc apparatus  20  moves to step S 451  (FIG. 5).  
         [0083]    At step S 451 , the optical disc apparatus  20  determines whether or not a format interrupt is requested by the host. For this determination, the optical disc apparatus  20  refers to the format interrupt request flag, and if the format interrupt request flag is not set as “1”, the optical disc apparatus  20  determines that the format interrupt is not requested (step S 451 : N) and moves to step S 453 .  
         [0084]    At step S 453 , the optical disc apparatus determines whether or not the optical disc apparatus  20  is requested to eject the optical disc  21 . For this determination, the optical disc apparatus  20  refers to the ejection request flag, and if the ejection request flag is set as “0”, the optical disc apparatus  20  determines that the ejection is not requested (step S 453 : N) and moves to step S 455 .  
         [0085]    At step S 455 , the optical disc apparatus  20  determines whether or not the optical disc  21  has been formatted. For this determination, the optical disc apparatus  20  determines whether or not there is an unrecorded area in the DZA, and if the DZA has an unrecorded area, the optical disc apparatus  20  determines that the optical disc  21  has not been completely formatted, and the optical disc  21  currently stays in the status of a blank disc. Therefore, the optical disc apparatus  20  determines that formatting of the optical disc  21  is not completed (step S 455 : N) and moves to step S 457 .  
         [0086]    At step S 457 , the optical disc apparatus  20  determines whether or not the optical disc apparatus  20  is requested to record and reproduce data in the optical disc  21  by the host. For this determination, the optical disc apparatus  20  refers to the write request flag and the read request flag, and if both of the write request flag and the read request flag are set as “0”s, the optical disc apparatus  20  determines that the optical disc apparatus  20  has not received the write request or the read request for the optical disc  21  (step S 457 : N) and moves to step S 459 .  
         [0087]    At step S 459 , the optical disc apparatus  20  formats the optical disc  21 . Namely, for example, the optical disc apparatus  20  records  16  sectors of dummy data in a unrecorded area in the DZA and returns to step S 451 .  
         [0088]    In order to format the optical disc  21 , the optical disc apparatus  20  repeats the above-mentioned steps S 451 , S 453 , S 455  and S 457  until these steps are satisfied.  
         [0089]    On the other hand, if the format interrupt request flag is set as “1” at step S 451 , the optical disc apparatus  20  determines that the format interrupt is requested (step S 451 : Y) and moves to step S 471 .  
         [0090]    At step S 471 , the optical disc apparatus  20  performs a format interrupt process. Namely, if there is an unrecorded area between the LWA and the head address of the DZA, the optical disc apparatus  20  records dummy data in the unrecorded area. In addition, the optical disc apparatus  20  updates the FDCB in the LIA and records the TLO immediately following the LWA. As a result, it is possible to maintain compatibility with a DVD-ROM. After completion of the format interrupt process, the optical disc apparatus  20  terminates the operation that responds to the receipt of the format request command from the host.  
         [0091]    On the other hand, if the ejection request flag is set as “1” at step S 453 , the optical disc apparatus  20  determines that the ejection is requested at step S 453  (step S 453 : Y) and moves to step S 473 .  
         [0092]    At step S 473 , after resetting the ejection request flag as “0”, the optical disc apparatus  20  informs the host of error information so as to prompt the host to issue a format interrupt request and then returns to step S 451 .  
         [0093]    On the other hand, if the formatting of the optical disc  21  is completed at step S 455 , the optical disc apparatus  20  determines that the optical disc  21  has been formatted (step S 455 : Y). In this case, the optical disc apparatus  20  records predetermined information in the initial zone, the inner disc test zone and the inner drive test zone in the LIA. After updating the FDCB, the optical disc apparatus  20  terminates the operation that responds to the receipt of the format request command from the host.  
         [0094]    On the other hand, if the write request flag or the read request flag is set as “1” at step S 457 , the optical disc apparatus  20  determines that the optical disc apparatus  20  has received the write request or the read request for the optical disc  21  (step S 457 : Y) and moves to step S 461 .  
         [0095]    At step S 461 , the optical disc apparatus  20  refers to the write request flag, and if the write request flag is set as “1”, the optical disc apparatus  20  determines that the optical disc apparatus  20  has received a write request (step S 461 : Y) and moves to step S 463 .  
         [0096]    At step S 463 , after resetting the write request flag as “0”, the optical disc apparatus  20  records given user data in a designated area in the DZA. After recording the user data, the optical disc apparatus  20  returns to step S 451 .  
         [0097]    On the other hand, if the write request flag is not set as “1” at step S 461 , the optical disc apparatus  20  determines that the optical disc apparatus  20  has not received any write request (step S 461 : N), that is, the optical disc apparatus determines that the optical disc apparatus  20  has received a read request, and moves to step S 465 .  
         [0098]    At step S 465 , after resetting the read request as “0”, the optical disc apparatus  20  reproduces user data recorded in an area designated by the host and transfers the designated user data to the host. After completion of reproducing the designated user data, the optical disc apparatus  20  returns to step S 451 .  
         [0099]    A description will now be given, with reference to FIG. 7, of an operation of the optical disc apparatus  20  in response to receipt of an FDCB request command from the host for requesting FDCB information of the optical disc  21 . In response to the receipt of the FDCB request command, the optical disc apparatus  20  sets the head address of a program corresponding to a procedure illustrated in FIG. 7 to a program counter of the CPU  40  and then starts execution of the program.  
         [0100]    [0100]FIG. 7 is a flowchart of an exemplary operation of the optical disc apparatus  20  in response to receipt of the FDCB request command. Referring to FIG. 7, the optical disc apparatus  20  determines whether or not disc initialization for the optical disc  21  is completed at step S 481 . For this determination, the optical disc apparatus  20  determines whether or not predetermined management information is recorded in the addresses 02DC80 through 030000. If there is an unrecorded area in the addresses 02DC80 through 030000, the optical disc apparatus  20  determines that the disc initialization is not completed (step S 481 : N) and moves to step S 483 .  
         [0101]    At step S 483 , the optical disc apparatus  20  creates FDCB information to be sent to the host and moves to step S 485 .  
         [0102]    At step S 485 , the optical disc apparatus  20  delivers the created FDCB information to the host and then terminates the operation that responds to the receipt of the FDCB request command.  
         [0103]    On the other hand, if the predetermined management information is recorded in the addresses 02DC80 through 030000 at step S 481 , the optical disc apparatus  20  determines that the disc initialization is completed (step S 481 : Y) and moves to step S 487 .  
         [0104]    At step S 487 , the optical disc apparatus  20  loads the FDCB information from the LIA and moves to step S 485 .  
         [0105]    At step S 485 , the optical disc apparatus  20  delivers the loaded FDCB information to the host and then terminates the operation that responds to the receipt of the FDCB request command.  
         [0106]    A description will now be given of a recording process performed by the optical disc apparatus  20 .  
         [0107]    The CPU  40  generates a control signal for controlling rotation of the spindle motor  22  based on a designated recording speed and supplies the generated control signal to the motor driver  27 . At the same time, the CPU  40  informs the reproduction signal processing circuit  28  that the CPU  40  has received a write request command from the host. In addition, the CPU  40  instructs the buffer manager  37  to store user data received from the host in the buffer RAM  34 .  
         [0108]    When the rotational speed of the optical disc  21  reaches a predetermined linear speed, the reproduction signal processing circuit  28  extracts a tracking error signal and a focusing error signal based on an output signal of the receiver of the optical pickup device  23  and supplies the extracted signals to the servo controller  33 . The servo controller  33  drives the focusing actuator and the tracking actuator of the optical pickup device  23  via the motor driver  27  based on the focusing error signal and the tracking error signal so as to correct a misaligned focusing position and a misaligned tracking position, respectively. Also, the reproduction signal processing circuit  28  obtains ADIP information based on an output signal of the receiver of the optical pickup device  23  and then sends the CPU  40  the ADIP information.  
         [0109]    Based on the ADIP information, the CPU  40  supplies a control signal for controlling the seek motor of the optical pickup device  23  to the motor driver  27  so that the optical pickup device  23  can be located at the writing start position thereof. When the CPU receives from the buffer manager  37  notification that the amount of user data accumulated in the buffer RAM  34  exceeds a predetermined data amount, the CPU  40  instructs the encoder  25  to generate a write signal. In addition, when the CPU  40  determines that the optical pickup device  23  is placed at the writing start position based on the ADIP information, the CPU  40  informs the encoder  25  of this fact. In this fashion, the optical disc apparatus  20  is ready to record the user data in the optical disc  21  via the encoder  25 , the laser control circuit  24  and the optical pickup device  23 .  
         [0110]    A description will now be given of a reproducing process performed by the optical disc apparatus  20 .  
         [0111]    The CPU  40  generates a control signal for controlling rotation of the spindle motor  22  based on a designated reproducing speed and supplies the control signal to the motor driver  27 . At the same time, the CPU  40  informs the reproduction signal processing circuit  28  that the CPU  40  has received a read request command. As in the above-explained recording process, the reproduction signal processing circuit  28  corrects a misaligned focusing position and a misaligned tracking position and informs the CPU  40  of ADIP information.  
         [0112]    The CPU  40  generates a control signal for controlling the seek motor of the optical pickup device  23  so that the optical pickup device  23  can be located at the writing start position based on the ADIP information and supplies the control signal to the motor driver  27 . Then, when the CPU  40  determines that the optical pickup device  23  is placed at the reading start position based on the ADIP information, the CPU  40  informs the reproduction signal processing circuit  28  of this fact.  
         [0113]    The reproduction signal processing circuit  28  extracts an RF signal from an output signal of the receiver of the optical pickup device  23 . After performing a decoding process and an error correction process, the reproduction signal processing circuit  28  stores the resulting signal as reproduction data in the buffer RAM  34 . The reproduction data are accumulated in the buffer RAM  34  until the reproduction data become sector data. After the accumulation of the reproduction data is completed, the reproduction data are delivered to the host via the interface  38 .  
         [0114]    Here, until the recording process and the reproducing process are terminated, the reproduction signal processing circuit  28  is extracting a focusing error signal and a tracking error signal from an output signal of the receiver of the optical pickup device  23  and is correcting a misaligned focusing position and a misaligned tracking position via the servo controller  33  and the motor driver  27 .  
         [0115]    In the first embodiment of the present invention, the optical disc apparatus comprises a termination information output part, an initialization part, a response part, an initialization interrupt part, a user data recording part and an initialization restart part. These components are implemented through execution of the first recording control program, which is installed in the ROM  39  and is coded based on the above-mentioned procedure in FIG. 4, FIG. 5 and FIG. 7, by the CPU  40  as a control unit of the optical disc apparatus  20 . Specifically, the termination information output part is implemented through step S 401  in FIG. 4, the initialization part is implemented through step S 407  in FIG. 4, the initialization interrupt part is implemented through step S 417  in FIG. 4, the user data recording part is implemented through step S 405  in FIG. 4, the initialization restart part is implemented through step S 423  in FIG. 4, and the response part is implemented through steps S 483  and S 485  in FIG. 7. However, the present invention is not limited to this embodiment. For example, although the above-mentioned components are implemented as the processes that follow the program executed by the CPU  40 , at least one of the components may be implemented as a hardware component.  
         [0116]    Also, in the first embodiment of the present invention, an inventive information recording method comprises a first step, a second step, a third step, a fourth step and a fifth step. The first step is implemented through step S 401  in FIG. 4, the second step is implemented through step S 407  in FIG. 4, the third step is implemented through step S 483  in FIG. 7, the fourth step is implemented through step S 417  in FIG. 4, and the fifth step is implemented through step S 423  in FIG. 4.  
         [0117]    According to one aspect of the first embodiment of the present invention, if the optical disc  21  is a DVD+RW, the optical disc apparatus  20  informs the host that the optical disc  15  has been formatted immediately after receipt of a format request command. Accordingly, even if the optical disc  21  is a blank disc, the optical disc apparatus  20  is capable of recording given user data immediately after loading of the optical disc  21  in the optical disc apparatus  20 . As a result, it is possible to reduce waiting time required for the optical disc apparatus  20  to be ready to record the user data in the optical disc  21 .  
         [0118]    Additionally, according to one aspect of the first embodiment of the present invention, if the optical disc apparatus  20  receives a write request command from the host during disc initialization, the optical disc apparatus  20  interrupts the disc initialization and starts a recording process. As a result, the optical disc apparatus  20  can record given user data immediately in response to the receipt of the write request. Hence, it is possible to reduce waiting time required for the optical disc apparatus  20  to be ready to record the user data in the optical disc  21 .  
         [0119]    Additionally, according to one aspect of the first embodiment of the present invention, while the optical disc apparatus  20  has no write request, the optical disc apparatus  20  performs disc initialization. Accordingly, it is possible to efficiently initialize the optical disc  21 .  
         [0120]    Additionally, according to one aspect of the first embodiment of the present invention, if disc initialization is not completed at receipt time of an FDCB request command, the optical disc apparatus  20  creates FDCB information and supplies the FDCB information to the host. As a result, even if the disc initialization is performed as a background process, it is possible to provide proper disc information to the host at any time.  
         [0121]    Additionally, according to one aspect of the first embodiment of the present invention, even if the optical disc apparatus  20  receives a format interrupt request command before completion of disc initialization, the optical disc apparatus  20  does not start a format interrupt process until the disc initialization is completed. Accordingly, the optical disc apparatus can reliably complete the disc initialization.  
         [0122]    As mentioned above, when receiving an ejection request command before completion of formatting of the optical disc  21 , the optical disc apparatus  20  according to the first embodiment sends error information to the host so as to prompt the host to issue an interrupt of the formatting. However, if an ejection request is received via an ejection switch of the optical disc apparatus  20 , the optical disc apparatus  20  may deal with the ejection request similarly to a format interrupt request command.  
         [0123]    Also, the first recording control program according to the first embodiment of the present invention is recorded in the ROM  39 . However, the first recording control program may be recorded in other types of recording media such as a CD-ROM, a magneto optical disc, a flash memory and a flexible disc. In this case, a drive device corresponding to a selected recording medium is provided to the optical disc apparatus  20 , and the first recording control program is installed via the drive device. In other words, the first recording control program may be stored in an arbitrary recording medium as long as the first recording control program can be adequately loaded in the main memory of the CPU  40  for execution.  
         [0124]    A description will now be given of an optical disc apparatus according to a second embodiment of the present invention.  
         [0125]    The optical disc apparatus of the second embodiment has the same configuration as the optical disc apparatus according to the first embodiment except that the optical disc apparatus according to the second embodiment handles the optical disc  21  in compliance with a DVD+R standard. The optical disc apparatus according to the second embodiment operates in accordance with a second recording control program stored in the ROM  39 . In the following, a difference between the optical disc apparatuses according to the two embodiments is intensively described. In the second embodiment, the same parts as those of the first embodiment are designated by the same reference numerals and a description thereof is omitted.  
         [0126]    Similarly to a DVD+RW, a LIA, as illustrated in FIG. 3, occupies the addresses 01D830 through 030000 and comprises 12 zones: an initial zone, an inner disc test zone, an inner drive test zone, a guard zone  1 , a reserved zone  1 , a reserved zone  2 , an inner disc identification zone, a reserved zone  3 , a reference code zone, a buffer zone  1 , a control data zone and a buffer zone  2 .  
         [0127]    In DVD+R, a multiple session system and a multi-track recording system are adopted, and therefore a data recording state of a DVD+R is managed by units of one track. For this reason, a session disc control block (SDCB), which contains information regarding each track in one session of a DVD+R, is stored in the inner disc identification zone.  
         [0128]    Also, data are not allowed to be overwritten in a DVD+R. Accordingly, whenever an additional track is provided in a DVD+R, SDBC of the additional track is recorded in the inner disc identification zone. Here, the inner disc identification zone has 16 areas for storing SDCB. Thus, at most 16 tracks are allowed to be recorded in one session.  
         [0129]    Also, physical format information, which contains start address information and last address information of a data area of a DVD+R, is recorded in the control data zone similarly to a DVD+RW.  
         [0130]    A description will now be given, with reference to FIG. 8, of an operation of the optical disc apparatus  20  according to the second embodiment of the present invention in response to receipt of a write request command from the host. In response to receipt of a write request command, the optical disc apparatus  20  sets the head address of the second recording control program corresponding to the flowchart in FIG. 8 to a program counter of the CPU  40  and starts the operation that responds to the receipt of the write request command.  
         [0131]    [0131]FIG. 8 is a flowchart of an exemplary operation of the optical disc apparatus  20  in response to receipt of a write request command. Referring to FIG. 8, the optical disc apparatus  20  starts to record given user data in an area designated by the host at step S 601  and moves to step S 602 .  
         [0132]    At step S 602 , the optical disc apparatus determines whether or not the user data have been recorded. If the recording of the user data is not completed, the optical disc apparatus  20  determines that the user data have not been recorded (step S 602 : N) and returns to step S 601 . On the other hand, if the recording of the user data is completed, the optical disc apparatus  20  determines that the user data have been recorded (step S 602 : Y) and moves to step S 603 .  
         [0133]    At step S 603 , the optical disc apparatus  20  determines whether or not predetermined management information has been recorded in the LIA of the optical disc  21 . For this determination, the optical disc apparatus  20  determines whether or not the management information has been recorded in the reserved zone  2  and a portion of the inner disc identification zone. If the recording of the management information is not completed, the optical disc apparatus  20  determines that the management information has not been recorded (step S 603 : N) and moves to step S 605 .  
         [0134]    At step S 605 , the optical disc apparatus  20  records the management information in the reserved zone  2  and the portion of the inner disc identification zone. After completion of the recording of the management information, the optical disc apparatus  20  terminates the operation that responds to receipt of the write request command.  
         [0135]    On the other hand, if the recording of the management information is completed at step S 603 , the optical disc apparatus  20  determines that the management information has been recorded (step S 603 : Y) and terminates the operation that responds to receipt of the write request command.  
         [0136]    Here, the remaining management information is recorded in the LIA in accordance with a predetermined recording format when the optical disc apparatus  20  receives a session close request from a user.  
         [0137]    A description will now be given, with reference to FIG. 9, of an operation of the optical disc apparatus  20  according to the second embodiment of the present invention in response to receipt of a SDCB request command for requesting SDCB information of the optical disc  21 . In response to receipt of the SDCB request command, the optical disc apparatus  20  sets the head address of a program corresponding to a flowchart in FIG. 9 to a program counter of the CPU  40  and starts the operation.  
         [0138]    [0138]FIG. 9 is a flowchart of an operation of the optical disc apparatus  20  in response to receipt of a SDCB information request command. Referring to FIG. 9, the optical disc apparatus  20  determines whether or not the latest management information has been recorded at step S 651 . If the recording of the latest management information is not completed, the optical disc apparatus determines that the latest management information has not been recorded (step S 651 : N) and moves to step S 653 .  
         [0139]    At step S 653 , the optical disc apparatus  20  creates SDCB information to be sent to the host and moves to step S 655 .  
         [0140]    At step S 655 , the optical disc apparatus  20  sends the created SDCB information to the host and terminates the operation that responds to receipt of the SDCB request command.  
         [0141]    On the other hand, if the recording of the latest management information is completed, the optical disc apparatus  20  determines that the latest management information has been recorded (step S 651 : Y) and moves to step S 657 .  
         [0142]    At step S 657 , the optical disc apparatus  20  reads SDCB information from the LIA of the optical disc  21  and moves to step S 655 .  
         [0143]    At step S 655 , the optical disc apparatus  20  sends the read SDCB information to the host and terminates the operation that responds to receipt of the SDCB request command.  
         [0144]    In the second embodiment of the present invention, the optical disc apparatus comprises a user data recording part, a management information recording part and a response part so as to perform a recording process and a reproducing process similarly to the first embodiment. These components are implemented through execution of the second recording control program, which is installed in the ROM  39  and is coded based on the above-mentioned procedure in FIG. 8 and FIG. 9, by the CPU  40  as a control unit of the optical disc apparatus  20 . Specifically, the user data recording part is implemented through step S 601  in FIG. 8, the management information recording part is implemented through step S 605  in FIG. 8, and the response part is implemented through steps S 653  and S 655  in FIG. 9. However, the present invention is not limited to this embodiment. For example, although the above-explained components are implemented as the processes that follow the program executed by the CPU  40 , at least one of the components may be implemented as a hardware component.  
         [0145]    Also, in the second embodiment of the present invention, an inventive information recording method comprises a first step, a second step and a third step. Specifically, the first step is implemented through step S 601  in FIG. 8, the second step is implemented through step S 605  in FIG. 8, the third step is implemented through step S 653  in FIG. 9.  
         [0146]    According to one aspect of the second embodiment of the present invention, if the optical disc  21  is a DVD+R, the optical disc apparatus  20  performs the recording process for the optical disc  15  immediately after receipt of a write request command. Accordingly, even if the optical disc  21  is a blank disc, the optical disc apparatus  20  is capable of recording given user data immediately after loading of the optical disc  21  into the optical disc apparatus  20 . As a result, it is possible to reduce waiting time required before the optical disc apparatus  20  is ready to record the user data in the optical disc  21 .  
         [0147]    Additionally, according to one aspect of the second embodiment of the present invention, if recording of the latest management information is not completed at receipt time of an SDCB request command, the optical disc apparatus  20  creates SDCB information and supplies the SDCB information to the host. As a result, even if the recording of the latest management information is performed as a background process, it is possible to provide proper disc information to the host at any time.  
         [0148]    Here, the second recording control program according to the second embodiment of the present invention is recorded in the ROM  39 . However, the second recording control program may be recorded in other types of recording media such as a CD-ROM, a magneto optical disc, a flash memory and a flexible disc. In this case, a drive device corresponding to a selected recording medium is provided to the optical disc apparatus  20 , and the second recording control program is installed via the drive device. In other words, the second recording control program may be stored in an arbitrary recording medium as long as the second recording control program can be adequately loaded in the main memory of the CPU  40  for execution.  
         [0149]    In the above-mentioned embodiments, the present invention is embodied as optical disc apparatuses that can record and reproduce information. However, the present invention is not limited to a specific type of optical disc apparatus. It is sufficient that the present invention can be embodied as an optical disc apparatus that can at least record information among a recording operation, a reproducing operation and a deleting operation.  
         [0150]    Additionally, in the above-mentioned embodiments, a DVD+RW and a DVD+R are used as information recording media. However, the present invention is not limited to these information recording media. The present invention may handle an arbitrary information recording medium as long as management information has to be recorded in the information recording medium.  
         [0151]    Additionally, in the above-mentioned embodiment, various types of request commands are issued by a host. However, the present invention is not limited to the embodiments. At least one of the request commands may be issued by request means provided in an information recorder. For instance, in a DVD recorder capable of recording video information, various request commands may be issued by a control device of the DVD recorder without being sent via a host.  
         [0152]    The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.  
         [0153]    The present application is based on Japanese Patent Priority Applications No. 2002-272372 filed Sep. 19, 2002 and No. 2003-127890 filed May 6, 2003, the entire contents of which are hereby incorporated by reference.