Abstract:
An optical disc drive includes a memory stored a write strategy, a converting unit which converts a recording data into a recording pulse based on the write strategy stored in the memory, an inspection unit which inspects a state of the recording data from a reproducing signal, a recording controller which executes a recording operation to record the recording data by applying a laser beam corresponding to the recording pulse to an optical disc, suspends the recording operation, judges whether correction of the write strategy according to an inspection result of the inspection unit is necessary, and restarts the recording operation after the write strategy saved in the memory is collected, and a correction unit which corrects the write strategy saved in the memory when the correction of the write strategy according to an inspection result of the inspection unit is necessary.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2006-015061, filed Jan. 24, 2006, the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an optical disc drive and a recording method, which are capable of changing recording conditions to obtain high recording quality. 
         [0004]    2. Description of the Related Art 
         [0005]    In the conventional system which sets recording conditions based on the information stored in media, high recording quality is not necessarily obtained because of the different recording characteristics caused by the difference in hardware such as an optical head. 
         [0006]    Even in a system which designs recording conditions suitable for a recording medium having a unique ID, when designing a drive, high recording quality is not necessarily obtained in all drives in mass production because of the difference in the characteristics of each drive. 
         [0007]    It is thus difficult to control variations in the recording quality. In addition, there is another problem of ensuring a memory area to store recording conditions for each medium. 
         [0008]    Jpn. Pat. Appln. KOKAI Publication No. 2004-355727 discloses the technique which executes test recording in a certain write strategy and corrects the write strategy according to a reproducing signal in the test recording, in order to obtain high recording quality. 
         [0009]    The paragraph 0089 of the above document states “PCA (Power Calibration Area) may be used for optical discs, such as CD-R and DVD-R, for example, and a part or all of data recording area may be used for an optical disc based on the Z-CLV recording system”. 
         [0010]    However, in the method of the above Application, in order to detect the difference in various set parameters in each strategy, it is necessary to make test recording of any one of the following patterns for detecting the difference in various set parameters of each strategy, by using different two kinds of strategies. 
       Reproducing pattern consisting of fixed length pit, fixed length land, and variable length pit 
     Reproducing pattern consisting of variable length pit, fixed length land, and fixed length pit 
     Reproducing pattern consisting of variable length land, fixed length land, and fixed length land 
     Reproducing pattern consisting of fixed length land, fixed length pit, and variable length land 
       [0011]    However, in discs of CD-R and DVD-R standards, test recording area exists only in the innermost or outermost periphery of a disc, and test recording is impossible in a user data area occupying most area of the inner to outer tracks, and correction of strategy is difficult. 
         [0012]    Further, even if test recording pattern is not the above specific pattern but a user data pattern, a recording quality may become not to be reproduced if a strategy is not optimized before recording. Thus, test recording in a user data area is difficult in CD-R and DVD-R discs. 
       BRIEF SUMMARY OF THE INVENTION 
       [0013]    According to one aspect of the present invention, there is provided an optical disc drive comprising: a memory stored a write strategy; a converting unit which converts a recording data into a recording pulse based on the write strategy stored in the memory; an inspection unit which inspects a state of the recording data from a reproducing signal; a recording controller which executes a recording operation to record the recording data by applying a laser beam corresponding to the recording pulse to an optical disc, suspends the recording operation, judges whether correction of the write strategy according to an inspection result of the inspection unit is necessary, and restarts the recording operation after the write strategy saved in the memory is collected; and a correction unit which corrects the write strategy saved in the memory when the correction of the write strategy according to an inspection result of the inspection unit is necessary. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0014]      FIG. 1  is a block diagram showing a system configuration of an optical disc drive according to an embodiment of the invention; 
           [0015]      FIG. 2  is a block diagram showing a system configuration for writing information on an optical disc of the optical disc drive of  FIG. 1 ; 
           [0016]      FIGS. 3A and 3B  are diagrams showing a recording speed corresponding to an address of an optical disc; 
           [0017]      FIG. 4  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0018]      FIG. 5  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0019]      FIG. 6  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0020]      FIG. 7  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0021]      FIG. 8  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0022]      FIG. 9  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0023]      FIG. 10  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0024]      FIG. 11  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0025]      FIG. 12  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0026]      FIG. 13  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0027]      FIG. 14  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; 
           [0028]      FIG. 15  is a flowchart showing a procedure of recording operation according to an embodiment of the invention; and 
           [0029]      FIG. 16  is a diagram used for explaining the principle of measuring a strategy correction amount. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    Embodiments of the invention will be explained herein with reference to the accompanying drawings. 
         [0031]      FIG. 1  is a block diagram showing a system configuration of an optical disc drive according to an embodiment of the invention. 
         [0032]    In an optical disc drive  10 , data D 1  given sequentially from a host computer HC is sequentially stored in a buffer  12  through an interface  11 , in a recording mode. 
         [0033]    The data stored in the buffer memory  12  is sequentially supplied to an encoder  20  by units of sector (2 Kbytes). The encoder  20  comprises a parity adder  21 , a modulator  22 , and a write strategy unit  23 . The parity adder  21  adds an error correction code and synchronizing data to the data, and supplies the data to the modulator  22 . The modulator  22  performs a predetermined modulation for the data, for example, eight-to-fourteen modulation (EFM) if the data is recorded on a CD-R disc, and supplies the data to the write strategy unit  23 . The write strategy unit  23  generates a recording pulse suitable for recording from the modulated recording data, and supplies the data to a laser diode  31  of an optical pickup  30 . 
         [0034]    The laser diode  31  emits an optical beam corresponding to the recording pulse. The optical beam is applied to the recording surface of an optical disc  13  through a beam splitter  32  and an object lens  33 . 
         [0035]    When the optical beam is applied to the recording surface, a reflected light from the optical disc  13  is applied to a photodetector  34  through the object lens  33  and beam splitter  32 . The photodetector  34  converts an optical signal to an electric signal. 
         [0036]    The photodetector  34  generates a servo error signal such as a tracking error signal and a focus error signal, a push-pull signal, and a RF signal, based on the reflected light from the optical disc  13 . The servo error signal is supplied to the controller  37 , the push-pull signal is supplied to a physical address demodulator  36 , and the RF signal is supplied to a decoder  50  through an RF amplifier  35 . 
         [0037]    The servo controller  37  drives the optical disc  13  at a predetermined speed by controlling a spindle motor  42  through a spindle driver  40  based on the supplied servo error signal. The servo controller  37  moves an optical beam spot on the optical disc  13  (hereinafter called a beam spot) in the radial direction of the optical disc  13  along a data track (pre-group or land) formed on the recording surface of the optical disc  13 , by controlling a thread motor  41  through a thread driver  39  based on the servo error signal. Further, the servo controller  37  controls tracking and focus by controlling an actuator through an actuator driver  38  based on the servo error signal. 
         [0038]    The physical address demodulator  36  detects an absolute address of a beam spot at that time on the optical disc  13  by decoding a push-pull signal, and sends the address to a central processing unit (CPU)  17 . 
         [0039]    Namely, the physical address demodulator  36  extracts a wobble component contained in a push-pull signal by passing the push-pull signal through a built-in band-pass filter of a ±1 Hz range with a center frequency of 22.05 Hz, detects an absolute address of a beam spot placed at that time on the optical disc  13  by performing FM demodulation for the wobble component, and sends it to the CPU  17  as an address information signal. 
         [0040]    Each time the absolute address on the optical disc  13  obtained by the above decoding operation is changed (i.e., each time a sector to be scanned by a beam spot on the optical disc  13  is changed), the physical address demodulator  36  sends a sink suspend signal indicating the change to the CPU  17 . 
         [0041]    Based on the address information signal and sink suspend signal given by the physical address demodulator  36 , the CPU  17  sequentially recognizes a recording position of each time on the optical disk  13 , and executes a necessary control for recording a record data D 2  correctly on the optical disc  13  based on the result of recognition. 
         [0042]    In a play mode, like in a record mode, by controlling the servo controller  37 , the CPU  17  rotates the optical disc  13  at a predetermined speed, moves a beam spot along a data track of the optical disc  13 , and controls tracking and focus. 
         [0043]    Further, the CPU  17  emits an optical beam to the optical disc  13  by driving the laser diode  31 . As a result, the optical beam reflects on the recording surface of the optical disc  13 , and a read data read from the optical disc  13  obtained based on the reflected light is supplied from the photodetector  34  to the decoder  50  through the RF amplifier  35 . 
         [0044]    The decoder  50  comprises a PLL (Phase Locked Loop) circuit  51 , a Sync detector  52 , a demodulator  53 , and an error corrector  54 . The PLL circuit  51  extracts a clock CLK from the read data, and supplies the extracted clock CLK to the Sync detector  52  together with the read data. 
         [0045]    Based on the supplied clock CLK, the Sync detector  52  generates a window pulse P WIN  for detecting a synchronizing data with a pulse width larger than a data pattern of a synchronizing data D SYNC  by a predetermined bit in the front and end. By using the window pulse P WIN  for detecting a synchronizing data, the Sync detector  52  sequentially detects the synchronizing data D SYNC  from the read data D 3 , and sequentially sends the read data D 3  to the demodulator  53  in predetermined units based on the detection result. 
         [0046]    The read data D 3  is demodulated in the demodulator  53 , and supplied to the error corrector  54 . An error of the data is corrected in the error corrector  54 , and the data is converted to the original format before recording, and then the data is sent to the host compute HC through the buffer memory  12  and interface  11 . 
         [0047]    As described above, the optical disc drive  10  records the data given by the host computer HC in the optical disc  13 , reproduces the data recorded in the optical disc  13 , and sends the data to the host computer HC. 
         [0048]    Next, a system for writing information on the optical disc  13  will be explained with reference to a block diagram shown in  FIG. 2 . 
         [0049]    An RF signal obtained by playing the optical disc  13  is supplied to an asymmetry value (or βvalue) calculator  111  of an optimum recording power value learner  110 . The asymmetry value (or βvalue) calculator  111  calculates an asymmetry value or β value or γ value according to the kinds of an optical disc, and supplies the calculation result to the optimum recording power learner  110 . In case of a write-once optical disc, the optimum recording power value learner  110  obtains an optimum recording power value from the supplied β value and a target β value  132  stored in a ROM (Read Only Memory)  130 , for example, and saves the obtained value in a PW register  141 . 
         [0050]    A recording start address (add) detector  121  detects an address to start recording on the optical disc  13 , and supplies the detection result to a recording speed calculator  122 , a recording controller  100 , a recording power value adder  123 , and a STG calculator  124 . 
         [0051]    The recording speed calculator  122  calculates a recording speed according to a recording mode and a recording start address specified by the host computer HC, and supplies the calculation result to the recording controller  100 , the recording power value calculator  123 , and the STG calculator  124 . 
         [0052]    The recording power calculator  123  calculates a recording power value P(X) at a recording start address, according to a recording speed calculated by the recording speed calculator  122 , a recording start address detected by the recording start address detector  121 , recording power coefficient P0(0) saved in the PW register  141 , and a default power conversion equation  131  stored in the ROM  130 . 
         [0053]    The default power conversion equation  131  is as follows. 
         [0000]        P ( X )= P 0(0)×( AX   2   +BX+C ) 
         [0054]    Where A, B and C are constants, and X is a recording speed. 
         [0055]    The value of P0(0), the initial value of P0, is 1, and the value of P0 after P0 is corrected by n times is P0(n). 
         [0056]    The STG calculator  124  calculates a recording speed calculated by the recording speed calculator  122  and a strategy (STG) corresponding to a recording start address detected by the recording address detector  121 , by using a default strategy  133  and a strategy interpolation formula  134  stored in the ROM  130 , and saves them in a STG register  142 . 
         [0057]    The default strategy  133  is a strategy roughly adjusted beforehand (in a step of designing), and parameters corresponding to the recording speeds of 2×,  4 ×,  6 × and 8×, for example, are stored in the ROM  130 . A default strategy for a middle speed is determined by the parameters stored in the ROM  130  by calculation using the strategy interpolation formula  134  (e.g., linear interpolation). 
         [0058]    If test recording area is provided on a disc, a strategy may be adjusted by using test recording area by the method of the aforementioned document (Jpn. Pat. Appln. KOKAI Publication No. 2004-355727), without “previously having a default strategy”, and the obtained strategy may be used as a default strategy. 
         [0059]    A STG corrector  125  calculates a correction amount of strategy from a RF reproducing signal by a predetermined method, and supplies the correction result to a correction scale calculator  126  and the recording controller  100 . The correction scale calculator  126  calculates a scale of the calculated correction amount, and supplies the calculation result to the recording controller  100 . 
         [0060]    A counter  143  is incremented or reset by instructions from the recording controller  100 . 
         [0061]    In this disc drive, (an optical disc is handled by dividing into a first zone for recording at a speed of 3.3 to 4 times, a second zone for recording at a speed of 4 to 6 times, and a third zone for recording at a speed of 6 to 8 times, from inner tracks of an optical disc, as shown in  FIG. 3 . 
         [0062]    Actual recording operation will now be explained with reference to  FIGS. 4 to 15 . 
         [0063]    When receiving a recording instruction and a specified recording mode from the host computer HC, the optimum recording power value learner  110  performs optimum power calibration (OPC) on an optical disc by using two or more recording power values, and learns an optimum recording power value (step S 11 ). The optimum recording power value learner  110  saves a recording power coefficient P0(1) obtained from the learned optimum recording power P(XOPC) by using the following equation in the PW register  141 . 
         [0000]        P 0(1)= P ( X   OPC )/( AX   OPC   2   +BX   OPC   +C ) 
       (X OPC : Recording speed on execution of OPC) 
       [0064]    When performing OPC for a write-once optical disc, after the optimum recording power value learner  110  performs test recording by two or more recording power values in a power calibration area (PCA) provided in an optical disc, the asymmetry value calculator  111  calculates a recording power value characteristic, for example, an asymmetry value (or β value) from a reproducing RF signal for each recording power value, and calculates a recording power value from the recording power value characteristic of an asymmetry value (or β value) to satisfy a target asymmetry value (or β value) stored in the ROM  130 . When performing OPC for a rewritable optical disc, the optimum recording power value learner  110  assumes an optimum power value from a value of γ obtained from a modulation factor m and power P. During OPC, test writing is executed at a test writing speed corresponding to a specified recording speed and test by a strategy corresponding to the test writing speed. 
         [0065]    The recording start address detector  121  detects a recording start address (add) of the optical disc  13  (step S 12 ), and determines whether the recording start address (add) is the first zone or not (step S 13 ). The recording start address detector  121  supplies the detection result to the recording speed calculator  122 . 
         [0066]    When the recording start position is the first zone (the innermost zone) (Yes in step S 13 ), the recording start address (add) detector  121  informs the recording controller  100  and the recording power value calculator  123  of the recording start address and the fact that the recording start address is the first zone. 
         [0067]    The recording speed calculator  122  calculates a recording speed at a recording start address corresponding to a specified recording mode, and supplies the calculation result to the recording power value calculator  123  and STG calculator  124  (step S 14 ). 
         [0068]    The STG calculator  124  calculates a strategy (STG) corresponding to the recording speed and recording start address calculated in step S 14 , by using the default strategy  133  and the strategy interpolation formula  134 , and saves them in the STG register  142  (step S 15 ). 
         [0069]    The recording controller  100  resets the counter  143  to zero (step S 16 ). 
         [0070]    The recording power value calculator  123  calculates a recording power value at the recording start address (add) according to the recording speed calculated in step S 14 , the recording start address, and the recording power coefficient P0(n) saved in the PW register  141  (step S 17 ). 
         [0071]    The recording controller  100  records recording data of the length from a recording start address to a micro address (add) (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  in step S 15  and the recording power value calculated in step S 17 , and suspends the recording operation (step S 18 ). While the recording is suspended, rotation of the optical disc  13  is held without changing. 
         [0072]    The recording controller  100  reproduces the data of a predetermined address (100H blocks) from a block at a predetermined number of address (e.g., 150H blocks) before the recording suspend address, and lets the asymmetry value (or β value) calculator  111  calculate a β value from the reproducing RF signal (step S 19 ). Equivalent if an asymmetry value is used instead of a β value, but a β value is used in the following explanation. 
         [0073]    The recording controller  100  determines whether the measured β value satisfies predetermined conditions (e.g., standards) (step S 20 ). For example, in the operation here, the controller calculates an absolute value of the difference between the measured β value and target β value  132 , and determines whether the absolute value is less than a predetermined value (e.g., 1). 
         [0074]    When the absolute value is not less than the predetermined value (No in step S 20 ), the recording controller  100  calculates a new recording power coefficient P0(n+1) by the following equation (step S 21 ). 
         [0000]        P 0( n+ 1)={1+α(target β value−Measured β value)}× P 0( n ) 
         [0075]    Where P0(n) is the PW register  141  just before the suspension, and α is a constant (e.g., 0.01). For example, when α is 0.01 and (target β value−Measured β value)=1%, P0(n+1)=1.01×P0(n). 
         [0076]    The recording controller  100  changes the recording power coefficient saved in the PW register  141  to the required P0(n+1) (step S 22 ), and increments the counter  143  by one (step S 23 ). 
         [0077]    The recording controller  100  determines whether the count of the counter  143  is less than a predetermined value (e.g., 5) (step S 24 ). When the count is not less than 5 (No in step S 24 ), the recording controller  100  stops recording as a recording error (step S 25 ). When the count is less than 5 (Yes in step S 24 ), the recording controller  100  executes a loop of steps S 17  to S 24  until the difference between the calculated β value and target β value  132  is determined to be less than 1 in step S 20  or the count of the counter  143  is determined to be less than 5 in step S 24 . 
         [0078]    When an absolute value of the difference between the measured β value and target β value  132  is less than 1 (Yes in step S 20 ), the recording controller  100  resets the counter  143  (step S 26 ). 
         [0079]    The recording controller  100  reproduces data of the length of a predetermined number of addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and the STG corrector  125  calculates a correction amount of strategy from the reproducing RF signal by a predetermined method (step S 27 ). In step S 27 , correction amounts (correction amount of strategy) at the front end position and rear end position of a recording pulse of each signal (3T-11T in Digital Versatile Disc [DVD]) are calculated. 
         [0080]    There are following methods as a method of reading the front end and rear end positions of a recording pulse, and a strategy correction method. 
         [0081]              Method of Reading the Front End and Rear End Positions of a Recording Pulse           
         [0082]    The reading is possible by measuring the position that the reproducing RF signal crosses a reference line of the asymmetry value or β value with reference to a reproducing PLL clock (reproducing PLLCLK), as shown in  FIG. 16 . For example, measure the values of A and B by units of T/32 for each T, measure a plurality of the same T mark in order to increase accuracy, and obtain a mean value. 
         [0083]    The reference line of the asymmetry value or β value mentioned here is a slice level of a slicing circuit for binarization of the RF signal or a zero level of A coupling. 
         [0084]    In CD-R and DVD-R, user data is recorded by randomizing a shortest mark—longest mark and a smallest space—largest space, and a required item (the values of A and B mentioned above) can be measured with a desired accuracy by scanning a relatively small area (about 100H blocks in DVD-R). 
         [0085]    TOSHIBA LSI, TC9453FG is provided with a function of measuring the position that the RF signal crosses a reference line of symmetry with reference to the above reproducing PLL clock. Therefore, the above measurement can be easily done by using the TC9453FG. 
         [0086]              Method of Correcting a Strategy           
         [0087]    When the values of A and B of 5T mark measured by the above method are A=2T/ 32  and B=3T/32, hasten the pulse start position for the 5T mark before correction by 2T/32 on a time axis basis, and hasten the pulse end position for the 5T mark by 3T/32. Strategy correction is possible by making the same correction for the above 5T. 
         [0088]    The correction scale calculator  126  calculates a scale of strategy correction amount (step S 28 ). The correction scale calculator  126  calculates a square sum of correction amounts at the front and rear ends of each signal (3T-11T in DVD), for example. 
         [0089]    The recording controller  100  determines whether the scale of correction amount calculated by the correction scale calculator  126  satisfies predetermined conditions (e.g., standards) (step S 29 ). In step S 29 , whether the scale of correction amount is within a predetermined value is determined. If the scale of correction amount is not within a predetermined value (No in step S 29 ), the recording controller  100  changes the set value of the STG register  142  to the correction value obtained in step S 27  (step S 30 ), and increments the counter  143  by one (step S 31 ). The recording controller  100  determines whether the count is a predetermined value (e.g., less than 5) (step S 32 ). When the count is less than 5 (Yes in step S 32 ), the recording controller  100  writes recording data of the length of the micro address (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  and the recording power value obtained in step S 17 , and suspends the writing (step S 33 ). While the writing is suspended, rotation of the optical disc  13  is held without changing. The recording controller  100  executes a loop of steps S 27  to S 33  until the scale is determined to be within a predetermined value in step S 29 , or the count of the counter  143  is determined to be not less than 5 in step S 32 . 
         [0090]    When the scale of correction amount is determined to be within a predetermined value in step S 29  (Yes in step S 29 ), or the count is determined to be not less than 5 in step S 32  (No in step S 32 ), the recording controller  100  starts recording of non-recording data by using the strategy saved in the STG register  142  and the recording power value calculated in step S 17  (step S 34 ). 
         [0091]    When the non-recording data is larger than a predetermined address length (No in step S 35 ), the recording controller writes data of a predetermined address length on the optical disc  13 , and suspends the writing (step S 36 ). 
         [0092]    The recording controller goes back to step S 19 , and executes a loop of step S 19  to S 34  until the non-recording data becomes smaller than a predetermined address length (Yes in step S 35 ). 
         [0093]    When the non-recording data becomes smaller than a predetermined address length and all non-recording data has been recorded (Yes in step S 35 ), the recording controller  100  finishes the recording operation (step S 37 ). 
         [0094]    If the recording start address is not the first zone (No in step S 13 ), the recording start address detector  121  determines whether the recording start address (add) is the second zone or not (step S 38 ). The recording start address detector  121  supplies the detection result to the recording speed calculator  122 . 
         [0095]    If the recording start address is the second zone (Yes in step S 38 ), the recording start address detector  121  informs the recording controller  100  and the recording power value calculator  123  of the recording start address and the fact that the recording start address is the second zone. 
         [0096]    The STG calculator  124  calculates a strategy (STG) corresponding to a 4-time recording by using the default strategy  133  and the strategy interpolation formula  134 , and saves the result in the STG register  142  (step S 39 ). 
         [0097]    The recording controller  100  resets the counter  143  to  0  (step S 40 ). 
         [0098]    The recording power value calculator  123  calculates a recording power value at the recording start address (add) from the 4-time recording speed and the recording power coefficient P0(n) saved in the PW register  141  (step S 41 ). 
         [0099]    The recording controller  100  records non-recording data of the length from a recording start address to a micro address (add) (e.g., 200H blocks) on the optical disc  13  by using the 4-time speed record, the strategy saved in the STG register  142  saved in step S 39  and the recording power value calculated in step S 41 , and suspends the recording operation (step S 42 ). While the recording is suspended, rotation of the optical disc  13  is held without changing. 
         [0100]    Recording is not started at a maximum recordable speed X MAX  (add) at a recording start address. Because, there is a large difference between X OPC  and X MAX  (add), and as the difference between an optimum power value and an estimated power value at X MAX  (add) calculated based on X OPC  is increased, the recording quality is extremely reduced in some area. To prevent extreme decrease of recording quality in some area, an optimum power is optimized at a speed between X OPC  and X MAX  (add). 
         [0101]    The recording controller  100  reproduces data of the length of predetermined addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and lets the asymmetry value (or β value) calculator  111  calculate a β value from the reproducing RF signal (step S 43 ). 
         [0102]    The recording controller  100  determines whether the measured β value satisfies predetermined conditions (e.g., standards) (step S 44 ). For example, in the operation here, the controller calculates an absolute value of the difference between the measured β value and target β value  132 , and determines whether the absolute value is less than a predetermined value (e.g., 1). 
         [0103]    When the absolute value is not less than the predetermined value (No in step S 44 ), the recording controller  100  calculates a new recording power coefficient P0(n+1) by the following equation (step S 45 ). 
         [0000]        P 0( n+ 1)={1+α(target β value−Measured β value)}× P 0( n ) 
         [0104]    Where P0(n) is the PW register  141  just before the suspension, and α is a constant (e.g., 0.01). For example, when α is 0.01 and (target β value−Measured β value)=1%, P0(n+1)=1.01×P0(n). 
         [0105]    The recording controller  100  changes the recording power coefficient saved in the PW register  141  to the required P0(n+1) (step S 22 ), and increments the counter  143  by one (step S 47 ). 
         [0106]    The recording controller  100  determines whether the count of the counter  143  is less than a predetermined value (e.g., 5) (step S 48 ). When the count is not less than 5 (No in step S 48 ), the recording controller  100  stops recording as a recording error (step S 49 ). When the count is less than 5 (Yes in step S 48 ), the recording controller  100  executes a loop of steps S 41  to S 48  until the difference between the calculated β value and target β value  132  is determined to be less than 1 in step S 44  or the count of the counter  143  is determined to be not less than 5 in step S 48 . 
         [0107]    When an absolute value of the difference between the measured β value and target β value  132  is less than 1 in step S 44  (Yes in step  44 ), the recording controller  100  resets the counter  143  (step S 50 ). 
         [0108]    The recording controller  100  reproduces data of the length of a predetermined number of addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and the STG corrector  125  calculates a correction amount of strategy from the reproducing RF signal by a predetermined method (step S 51 ). In step S 51 , correction amounts (correction amount of strategy) at the front end position and rear end position of a recording pulse of each signal (3T-11T in DVD) are calculated. 
         [0109]    The correction scale calculator  126  calculates a scale of strategy correction amount (step S 52 ). The correction scale calculator  126  calculates a square sum of correction amounts at the front and rear ends of each signal (3T-11T in DVD), for example. 
         [0110]    The recording controller  100  determines whether the scale of correction amount calculated by the correction scale calculator  126  satisfies predetermined conditions (e.g., standards) (step S 53 ). If the scale of correction amount is not within a predetermined value (No in step S 53 ), the recording controller  100  changes the set value of the STG register  142  to the correction value obtained in step S 51  (step S 54 ), and increments the counter  143  by one (step S 55 ). The recording controller  100  determines whether the count is a predetermined value (e.g., less than 5) (step S 56 ). When the count is less than 5 (Yes in step S 56 ), the recording controller  100  writes recording data of the length of the micro address (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  and the recording power value obtained in step S 42 , and suspends the writing (step S 57 ). While the writing is suspended, rotation of the optical disc  13  is held without changing. The recording controller  100  executes a loop of steps S 51  to S 57  until the scale is determined to be within a predetermined value in step S 53 , or the count of the counter  143  is determined to be not less than 5 in step S 56 . 
         [0111]    When the scale of correction amount is determined to be within a predetermined value in step S 53  (Yes in step S 53 ), or the count is determined to be not less than 5 in step S 56  (No in step S 56 ), the recording controller  100  resets the counter  143  to  0  (step S 58 ). 
         [0112]    The recording speed calculator  122  calculates a recording speed {speed faster than 4×: a recording speed differs according to a radial position (address) when a rotation speed is constant} at a joint recording start address corresponding to a specified recording mode (step S 59 ). 
         [0113]    The STG calculator  124  calculates a strategy based on the strategy saved in the STG register  142  and the recording speed calculated in step S 59  (step S 60 ). The strategy saved in the STG register  142  is increased in accuracy in the loop of steps S 52  to S 57 . In step S 60 , a strategy is calculated based on the strategy increased in accuracy in the loop of steps S 52  to S 57 , and the accuracy is increased. 
         [0114]    The recording power value calculator  123  calculates a recording power value at the recording start address (add) from the recording speed calculated by the recording speed calculator  122  in step S 59 , and the recording power value saved in the PW register  141  (step S 61 ). 
         [0115]    The recording controller  100  records a part of recording data of the length from a recording start address to a micro address (add) (e.g., 200H blocks) on the optical disc  13  by using the recording speed calculated by the recording speed calculator  122  in step S 59 , the strategy saved in the STG register  142  in step S 60 , and the recording power value calculated in step S 61 , and suspends the recording operation (step S 62 ). While the recording is suspended, rotation of the optical disc  13  is held without changing. 
         [0116]    The recording controller  100  reproduces data of the length of predetermined addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and lets the asymmetry value (or β value) calculator  111  calculate a β value from the reproducing RF signal (step S 63 ). 
         [0117]    The recording controller  100  determines whether the measured β value satisfies predetermined conditions (e.g., standards) (step S 64 ). For example, in the operation here, the controller calculates an absolute value of the difference between the measured β value and target β value  132 , and determines whether the absolute value is less than a predetermined value (e.g., 1). 
         [0118]    When the absolute value is not less than the predetermined value (No in step S 64 ), the recording controller  100  calculates a new recording power coefficient P0(n+1) by the following equation (step S 65 ). 
         [0000]        P 0( n+ 1)={1+α(target β value−Measured β value)}× P 0( n ) 
         [0119]    Where P0(n) is the PW register  141  just before the suspension, and α is a constant (e.g., 0.01). For example, when α is 0.01 and (target β value−Measured β value)=1%, P0(n+1)=1.01×P0(n). 
         [0120]    The recording controller  100  changes the recording power coefficient saved in the PW register  141  to the required P0(n+1) (step S 66 ), and increments the counter  143  by one (step S 67 ). 
         [0121]    The recording controller  100  determines whether the count of the counter  143  is less than a predetermined value (e.g., 5) (step S 68 ). If the count is not less than 5 (No in step S 68 ), the recording controller  100  stops recording as a recording error (step S 69 ). If the count is less than 5 (Yes in step S 68 ), the recording controller  100  executes a loop of steps S 61  to S 68  until the difference between the calculated β value and target β value  132  is determined to be less than 1 in step S 64  or the count of the counter  143  is determined to be not less than 5 in step S 68 . 
         [0122]    When an absolute value of the difference between the measured β value and target β value  132  is less than 1 in step S 64  (Yes in S 64 ), the recording controller  100  resets the counter  143  (step S 70 ). 
         [0123]    The recording controller  100  reproduces data of the length of a predetermined number of addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and the STG corrector  125  calculates a correction amount of strategy from the reproducing RF signal by a predetermined method (step S 71 ). In step S 71 , correction amounts (strategy correction amount) at the front end and rear end positions of a recording pulse of each signal (3T-11T in DVD) are calculated. 
         [0124]    The correction scale calculator  126  calculates a scale of strategy correction amount (step S 72 ). The correction scale calculator  126  calculates a square sum of the correction amount at the front end and rear end of each signal (3T-11T in DVD), for example. 
         [0125]    The recording controller  100  determines whether the scale of correction amount calculated by the correction scale calculator  126  satisfies predetermined conditions (e.g., standards) (step S 73 ). If the scale of correction amount is not within a predetermined value (No in step S 73 ), the recording controller  100  changes the set value of the STG register  142  to the correction value obtained in step S 71  (step S 74 ), and increments the counter  143  by one (step S 75 ). The recording controller  100  determines whether the count is a predetermined value (e.g., less than 5) (step S 76 ). When the count is less than 5 (Yes in step S 76 ), the recording controller  100  writes a part of non-recording data of the length of the micro address (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  and the recording power value obtained in step S 61 , and suspends the writing (step S 77 ). While the writing is suspended, rotation of the optical disc  13  is held without changing. The recording controller  100  executes a loop of steps S 71  to S 77  until the scale is determined to be within a predetermined value in step S 73 , or the count of the counter  143  is determined to be not less than 5 in step S 76 . 
         [0126]    When the scale of correction amount is determined to be within a predetermined value in step S 73  (Yes in step S 73 ), or the count is determined to be not less than 5 in step S 76  (No in step S 76 ), the recording controller  100  starts recording of non-recording data by using the strategy saved in the STG register  142  and the recording power value calculated in step S 61  (step S 78 ). 
         [0127]    If the non-recording data is larger than a predetermined address length (No in step S 79 ), the recording controller writes data of a predetermined address length on the optical disc  13 , and suspends the writing (step S 80 ). 
         [0128]    The recording controller goes back to step S 63 , and executes a loop of steps S 63  to S 79  until the non-recording data becomes smaller than a predetermined address length (Yes in step S 79 ). 
         [0129]    When the non-recording data becomes smaller than a non-recording data of the length of a predetermined address and all non-recording data is recorded (Yes in step S 79 ), the recording controller  100  finishes the recording operation (step S 81 ). 
         [0130]    If the recording start position is determined not the second zone (No in step S 38 ), the recording start address detector  121  recognizes that the recording start address (add) is the third zone, and informs the recording controller  100  and the recording power value calculator of the recording start address and the fact that the recording start address is the third zone. 
         [0131]    The STG calculator  124  calculates a strategy (STG) corresponding to a 4-time recording by using the default strategy  133  and the strategy interpolation formula  134 , and saves the result in the STG register  142  (step S 82 ). 
         [0132]    The recording controller  100  resets the counter  143  to  0  (step S 83 ). 
         [0133]    The recording power value calculator  123  calculates a recording power value at the recording start address (add) from the 4-time recording speed and the recording power coefficient P0(n) saved in the PW register  141  (step S 84 ). 
         [0134]    The recording controller  100  records a part of recording data of the length from a recording start address to a micro address (add) (e.g., 200H blocks) on the optical disc  13  by using the 4-time speed record, the strategy saved in the STG register  142  in step S 82  and the recording power value calculated in step S 84 , and suspends the recording operation (step S 85 ). While the recording is suspended, rotation of the optical disc  13  is held without changing. 
         [0135]    Recording is not started at a maximum recordable speed X MAX  (add) at a recording start address. Because, there is a large difference between X OPC  and X MAX  (add), and as the difference between an optimum power value and an estimated power value at X MAX  (add) calculated based on X OPC  is increased, the recording quality is extremely decreased in some area. To prevent the decrease of recording quality in some area, an optimum power is optimized at a speed between X OPC  and X MAX  (add). 
         [0136]    The recording controller  100  reproduces data of the length of predetermined addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and lets the asymmetry value (or β value) calculator  111  calculate a β value from the reproducing RF signal (step S 86 ). 
         [0137]    The recording controller  100  determines whether the measured β value satisfies predetermined conditions (e.g., standards) (step S 87 ). For example, in the operation here, the controller calculates an absolute value of the difference between the measured β value and target β value  132 , and determines whether the absolute value is less than a predetermined value (e.g., 1). 
         [0138]    When the absolute value is not less than the predetermined value (No in step S 87 ), the recording controller  100  calculates a new recording power coefficient P0(n+1) by the following equation (step S 88 ). 
         [0000]        P 0( n+ 1)={1+α(target β value−Measured β value)}× P 0( n ) 
         [0139]    Where P0(n) is the PW register  141  just before the suspension, and α is a constant (e.g., 0.01). For example, when α is 0.01 and (target β value−Measured β value)=1%, P0(n+1)=1.01×P0(n). 
         [0140]    The recording controller  100  changes the recording power coefficient saved in the PW register  141  to the required P0(n+1) (step S 89 ), and increments the counter  143  by one (step S 90 ). 
         [0141]    The recording controller  100  determines whether the count of the counter  143  is less than a predetermined value (e.g., 5) (step S 91 ). When the count is not less than 5 (No in step S 91 ), the recording controller  100  stops recording as a recording error (step S 92 ). When the count is less than 5 (Yes in step S 91 ), the recording controller  100  executes a loop of steps S 84  to S 91  until the difference between the calculated β value and target β value  132  is determined to be less than 1 in step S 87  or the count of the counter  143  is determined to be not less than 5 in step S 91 . 
         [0142]    When an absolute value of the difference between the measured β value and target β value  132  is less than 1 in step S 87  (Yes in step  87 ), the recording controller  100  resets the counter  143  (step S 93 ). 
         [0143]    The recording controller  100  reproduces data of the length of a predetermined number of addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and the STG corrector  125  calculates a correction amount of strategy from the reproducing RF signal by a predetermined method (step S 94 ). In step S 48 , correction amounts (correction amount of strategy) at the front end position and rear end position of a recording pulse of each signal (3T-11T in DVD) are calculated. 
         [0144]    The correction scale calculator  126  calculates a scale of strategy correction amount (step S 95 ). The correction scale calculator  126  calculates a square sum of correction amounts at the front and rear ends of each signal (3T-11T in DVD), for example. 
         [0145]    The recording controller  100  determines whether the scale of correction amount calculated by the correction scale calculator  126  satisfies predetermined conditions (e.g., standards) (step S 96 ). When the scale of correction amount is not within a predetermined value (No in step S 96 ), the recording controller  100  changes the set value of the STG register  142  to the correction value obtained in step S 94  (step S 97 ), and increments the counter  143  by one (step S 98 ). The recording controller  100  determines whether the count is a predetermined value (e.g., less than 5) (step S 99 ). When the count is less than 5 (Yes in step S 99 ), the recording controller  100  writes a part of non-recording data of the length of the micro address (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  and the recording power value obtained in step S 84 , and suspends the writing (step S 100 ). While the writing is suspended, rotation of the optical disc  13  is held without changing. The recording controller  100  executes a loop of steps S 94  to S 99  until the scale is determined to be within a predetermined value in step S 96 , or the count of the counter  143  is determined to be not less than 5 in step S 99 . 
         [0146]    When the scale of correction amount is determined to be within a predetermined value in step S 96  (Yes in step S 96 ), or the count is determined to be not less than 5 in step S 99  (No in step S 99 ), the STG calculator  124  calculates a strategy (STG) corresponding to 6-time recording based on the strategy saved in the STG register  142  and the recording speed calculated in step S 84 , and saves it in the STG register  142  (step S 101 ). The strategy saved in the STG register  142  is increased in accuracy in the loop of steps S 96  to S 99 . In step S 103 , a strategy is calculated based on the strategy increased in accuracy in the loop of steps S 96  to S 99 , and the accuracy is increased. 
         [0147]    The recording controller  100  resets the counter  143  (step S 102 ). 
         [0148]    The recording power value calculator  123  calculates a recording power value at the recording start address (add) from the 6-time recording speed and the recording power coefficient P0(n) saved in the PW register  141  (step S 103 ). 
         [0149]    The recording controller  100  records a part of recording data of the length from a recording start address to a micro address (add) (e.g., 200H blocks) on the optical disc  13  by using the 6-time speed record, the strategy saved in the STG register  142  and the recording power value calculated in step S 103 , and suspends the recording operation (step S 104 ). While the recording is suspended, rotation of the optical disc  13  is held without changing. 
         [0150]    Recording is not started at a maximum recordable speed X MAX  (add) at a recording start address. Because, there is a large difference between 4× speed and X MAX  (add), and as the difference between an optimum power value and an estimated power value at X MAX  (add) calculated based on the optimum power value obtained at 4× is increased, the recording quality is extremely decreased in some area. To prevent the reduction of recording quality in some area, an optimum power is optimized at a speed between 4× and X MAX  (add). 
         [0151]    The recording controller  100  reproduces data of the length of predetermined addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and lets the asymmetry value (or β value) calculator  111  calculate a β value from the reproducing RF signal (step S 105 ). 
         [0152]    The recording controller  100  determines whether the measured β value satisfies predetermined conditions (e.g., standards) (step S 106 ). For example, in the operation here, the controller calculates an absolute value of the difference between the measured β value and target β value  132 , and determines whether the absolute value is less than a predetermined value (e.g., 1). 
         [0153]    When the absolute value is not less than the predetermined value (No in step S 106 ), the recording controller  100  calculates a new recording power coefficient P0(n+1) by the following equation (step S 107 ). 
         [0000]        P 0( n+ 1)={1+α(target β value−Measured β value)}× P 0( n ) 
         [0154]    Where P0(n) is the PW register  141  just before the suspension, and α is a constant (e.g., 0.01). For example, when α is 0.01 and (target β value−Measured β value)=1%, P0(n+1)=1.01×P0(n). 
         [0155]    The recording controller  100  changes the recording power coefficient saved in the PW register  141  to the required P0(n+1) (step S 108 ), and increments the counter  143  by one (step S 109 ). 
         [0156]    The recording controller  100  determines whether the count of the counter  143  is less than a predetermined value (e.g., 5) (step S 110 ). When the count is not less than 5 (No in step S 110 ), the recording controller  100  stops recording as a recording error (step S 111 ). When the count is less than 5 (Yes in step S 110 ), the recording controller  100  executes a loop of steps S 103  to S 110  until the difference between the calculated β value and target β value  132  is determined to be less than 1 in step S 105  or the count of the counter  143  is determined to be not less than 5 in step S 110 . 
         [0157]    When an absolute value of the difference between the measured β value and target β value  132  is less than 1 in step S 106  (Yes in step  106 ), the recording controller  100  resets the counter  143  (step S 112 ). 
         [0158]    The recording controller  100  reproduces data of the length of a predetermined number of addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and the STG corrector  125  calculates a correction amount of strategy from the reproducing RF signal by a predetermined method (step S 113 ). In step S 113 , correction amounts (correction amount of strategy) at the front end position and rear end position of a recording pulse of each signal (3T-11T in DVD) are calculated. 
         [0159]    The correction scale calculator  126  calculates a scale of strategy correction amount (step S 114 ). The correction scale calculator  126  calculates a square sum of correction amounts at the front and rear ends of each signal (3T-11T in DVD), for example. 
         [0160]    The recording controller  100  determines whether the scale of correction amount calculated by the correction scale calculator  126  satisfies predetermined conditions (e.g., standards) (step S 115 ). If the scale of correction amount is not within a predetermined value (No in step S 115 ), the recording controller  100  changes the set value of the STG register  142  to the correction value obtained in step S 113  (step S 116 ), and increments the counter  143  by one (step S 117 ). The recording controller  100  determines whether the count is a predetermined value (e.g., less than 5) (step S 118 ). When the count is less than 5 (Yes in step S 118 ), the recording controller  100  writes a part of recording data of the length of the micro address (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  and the recording power value obtained in step S 103 , and suspends the writing (step S 119 ). While the writing is suspended, rotation of the optical disc  13  is held without changing. The recording controller  100  executes a loop of steps S 113  to S 119  until the scale is determined to be within a predetermined value in step S 115 , or the count of the counter  143  is determined to be not less than 5 in step S 118 . 
         [0161]    When the scale of correction amount is determined to be within a predetermined value in step S 115  (Yes in step S 115 ), or the count is determined to be not less than 5 in step S 118  (No in step S 118 ), the recording controller  100  resets the counter  143  to  0  (step S 120 ). 
         [0162]    The recording speed calculator  122  calculates a recording speed {speed faster than 6×: a recording speed differs according to a radial position (address) when a rotation speed is constant} at a joint recording start address corresponding to a specified recording mode (step S 121 ). 
         [0163]    The STG calculator  124  calculates a strategy based on the strategy saved in the STG register  142  and the recording speed calculated in step S 121 , and saves the calculated strategy in the STG register  142  (step S 122 ). The strategy saved in the STG register  142  is increased in accuracy in a loop of steps S 113  to S 119 . In step S 122 , a strategy is calculated based on the strategy increased in accuracy in a loop of steps S 113  to S 129 , and the accuracy is increased. 
         [0164]    The recording power value calculator  123  calculates a recording power value at the recording start address (add) from the recording speed calculated by the recording speed calculator  122  in step S 121 , and the recording power value saved in the PW register  141  (step S 123 ). 
         [0165]    The recording controller  100  records a part of recording data of the length from a recording start address to a micro address (add) (e.g., 200H blocks) on the optical disc  13  by using the recording speed calculated by the recording speed calculator  122  in step S 121 , the strategy saved in the STG register  142  in step S 122 , and the recording power value calculated in step S 123 , and suspends the recording operation (step S 124 ). While the recording is suspended, rotation of the optical disc  13  is held without changing. 
         [0166]    The recording controller  100  reproduces data of the length of predetermined addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and lets the asymmetry value (or β value) calculator  111  calculate a β value from the reproducing RF signal (step S 125 ). 
         [0167]    The recording controller  100  calculates an absolute value of the difference between the measured β value and target β value  132 , and determines whether the absolute value is less than a predetermined value (e.g., 1) (step S 126 ). 
         [0168]    When the absolute value is not less than the predetermined value (No in step S 126 ), the recording controller  100  calculates a new recording power coefficient P0(n+1) by the following equation (step S 127 ). 
         [0000]        P 0( n+ 1)={1+α(target β value−Measured β value)}× P 0( n ) 
         [0169]    Where P0(n) is the PW register  141  just before the suspension, and α is a constant (e.g., 0.01). For example, when α is 0.01 and (target β value−Measured value)=1%, P0(n+1)=1.01×P0(n). 
         [0170]    The recording controller  100  changes the recording power coefficient saved in the PW register  141  to the required P0(n+1) (step S 128 ), and increments the counter  143  by one (step S 129 ). 
         [0171]    The recording controller  100  determines whether the count of the counter  143  is less than a predetermined value (e.g., 5) (step S 130 ). When the count is not less than 5 (No in step S 130 ), the recording controller  100  stops recording as a recording error (step S 131 ). When the count is less than 5 (Yes in step S 130 ), the recording controller  100  executes a loop of steps S 123  to S 130  until the difference between the calculated β value and target β value  132  is determined to be less than 1 in step S 126  or the count of the counter  143  is determined to be not less than 5 in step S 130 . 
         [0172]    When an absolute value of the difference between the measured β value and target β value  132  is less than 1 in step S 126  (Yes in S 126 ), the recording controller  100  resets the counter  143  (step S 132 ). 
         [0173]    The recording controller  100  reproduces data of the length of a predetermined number of addresses (100H blocks) from a block at a predetermined number of addresses (e.g., 150H blocks) before the recording suspend address, and the STG corrector  125  calculates a correction amount of strategy from the reproducing RF signal by a predetermined method (step S 133 ). In step S 133 , correction amounts (strategy correction amount) at the front end and rear end positions of a recording pulse of each signal (3T-11T in DVD) are calculated. 
         [0174]    The correction scale calculator  126  calculates a scale of strategy correction amount (step S 134 ). The correction scale calculator  126  calculates a square sum of correction amounts at the front end and rear end of each signal (3T-11T in DVD), for example. 
         [0175]    The recording controller  100  determines whether the scale of correction amount calculated by the correction scale calculator  126  satisfies is within a predetermined value (step S 135 ). When the scale of correction amount is not within a predetermined value (No in step S 135 ), the recording controller  100  changes the set value of the STG register  142  to the correction value obtained in step S 133  (step S 136 ), and increments the counter  143  by one (step S 137 ). The recording controller  100  determines whether the count is a predetermined value (e.g., less than 5) (step S 138 ). When the count is less than 5 (Yes in step S 138 ), the recording controller  100  writes a part of non-recording data of the length of the micro address (e.g., 200H blocks) on the optical disc  13  by using the strategy saved in the STG register  142  and the recording power value obtained in step S 123 , and suspends the writing (step S 139 ). While the writing is suspended, rotation of the optical disc  13  is held without changing. The recording controller  100  executes a loop of steps S 133  to S 139  until the correction scale is determined to be within a predetermined value in step S 135 , or the count of the counter  143  is determined to be not less than 5 in step S 138 . 
         [0176]    When the scale of correction amount is determined to be within a predetermined value in step S 135  (Yes in step S 135 ), or the count is determined to be not less than 5 in step S 138  (No in step S 138 ), the recording controller  100  starts recording of non-recording data by using the strategy saved in the STG register  142  and the recording power value calculated in step S 123  (step S 140 ). 
         [0177]    When the non-recording data is larger than a non-recording data of the length of a predetermined address (No in step S 141 ), the recording controller writes data of a predetermined address length on the optical disc  13 , and suspends the writing (step S 142 ). 
         [0178]    The recording controller goes back to step S 125 , and executes a loop of step S 125  to S 141  until the non-recording data becomes smaller than a predetermined address length (Yes in step S 141 ). 
         [0179]    When the non-recording data becomes smaller than a non-recording data of the length of a predetermined address and all non-recording data have been recorded (Yes in step S 141 ), the recording controller  100  finishes the recording operation (step S 143 ). 
         [0180]    As described hereinbefore, by correcting a write strategy while recording data, a write strategy can be corrected even if a recording speed is changed and a write strategy is deviated from a preferable strategy, and good recording quality can be obtained without performing test recording. 
         [0181]    As the recording characteristics of an optical disc is changed depending on the radius, a write strategy can be corrected even if deviated from a preferable strategy during recording, and good recording quality can be obtained without performing test recording. 
         [0182]    Further, a write strategy can be corrected even if an ambient temperature is changed during recording and a write strategy is deviated from a preferable strategy, and good recording quality can be obtained without performing without performing test recording. 
         [0183]    The invention is not limited to the embodiments described above, and may be embodied in a practical stage by modifying the constituent components without departing from the essential characteristics. The invention may be embodied in various modes by appropriately combining the components disclosed in the above embodiments. For example, some components may be eliminated from the constituent components shown in the embodiment. Components used in different embodiments may be appropriately combined.