JP2009015984A - Device and method for recording data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the influence of cross talk from an adjacent groove track without shifting the operation point of a phase detector. <P>SOLUTION: This device is provided with a land prepit error extraction means for extracting a land prepit error signal indicating a phase error between a land prepit detection signal Slpp and a recording clock signal included in a reproduction signal reproduced from a disk-like recording medium, a wobbling error extraction means for extracting a wobbling error signal indicating a phase error between a wobbling signal Swb and the recording clock signal Rclk, and a phase modulation portion eliminating means for eliminating phase modulation portion of the extracted wobbling signal Swb extracted by the wobbling error extraction means influenced by cross talk from an adjacent groove track. The phase modulation portion is eliminated by matching the unit of the land prepit error signal with the level of a phase detection signal between the wobbling signal and the recording clock signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data recording apparatus and a data recording method, and more particularly to a technique suitable for use in a clock generation apparatus for data recording on an optical disc.

  In recent years, CD-R and DVD-R have been used as inexpensive optical recording media. Each of these optical recording media has a disk shape, and spiral guide grooves are formed in advance in the manufacturing stage from the inner periphery to the outer periphery of the disk plane or from the outer periphery to the inner periphery. This guide groove, that is, a groove track is used as a data recording track. Further, the guide groove itself undulates (meanders and swings) with a predetermined amplitude and a single period, and this is called a wobble. This is shown in FIG.

  Since this groove track is wobbling, a reference frequency signal is generated by multiplying the signal obtained from the wobble, and this is used as a clock during recording, so that the positional relationship between the recording data and the groove track is accurately determined. It is possible to manage. At this time, as a specific clock generation method, that is, a PLL configuration, for example, the configuration of FIG. 3 can be considered.

  That is, by dividing the output of the VCO with respect to the wobble signal (assuming a sine wave), a carrier wave (cosine wave) whose phase is orthogonal to that of the wobble signal is generated, and the wobble signal and the carrier wave are multiplied. Detect a phase error signal. Then, the detected phase error signal is integrated by a loop filter, and a VLO (voltage controlled oscillator) is operated by the output signal.

  By the way, the DVD-R has a narrower pitch between tracks than the CD-R in order to realize high-density recording. At this time, the pitch between tracks is about half that of the CD-R.

  Thus, when the track pitch is narrowed, the influence of the reflected light from the groove track adjacent to the groove track irradiated with the light beam, that is, the influence of crosstalk with the adjacent track cannot be ignored. If the crosstalk cannot be ignored, the amplitude and phase of the wobble detected through the optical sensor will vary with time due to the influence of the crosstalk. In particular, the phase fluctuation leads to jitter in the recording clock signal generated from the wobble, making it difficult to accurately manage the positional relationship between the groove track and the recording data.

  Thus, as a technique for solving the above-described problem, Patent Document 1 proposes a recording clock signal generator. The recording clock signal generator has a data recording track wobbled by a wobble signal having a predetermined frequency component. A recording clock for recording data on an optical disc on which land pre-pits (LPP) having a predetermined phase relationship with the wobble signal are formed based on a recording clock signal phase-synchronized with the wobble signal Generate a signal.

  Among them, the recording clock signal generating means is a wobble signal extracting means for extracting the wobble signal, a wobble binary signal obtained by binarizing the wobble signal with a certain threshold value, and a recording clock signal obtained by frequency division. The phase is compared with the clock division signal for use. And means for generating a wobble / recording clock phase error signal.

  Further, the phase is compared between the previous wobble binarized signal and the output of the land prepit detection means for detecting the land prepit and generating the land prepit detection signal. Then, a method has been proposed in which the wobble / land pre-pit phase error signal is added to the wobble / recording clock phase error signal, a PLL is constituted by the output, and a recording clock signal is generated.

JP-A-10-293926

FIG. 3 shows a basic circuit configuration of the recording clock signal generator described in Patent Document 1.
This recording clock signal generation circuit includes a multiplier 201, a low-pass filter (LPF) 202, a loop filter 203, and a voltage controlled oscillator 204. Also, an N counter 205 and a COS wave generator 206 are provided.

  Consider a case in which a method of simply adding the wobble / recording clock phase error signal and the wobble / land pre-pit phase error signal is used in the recording clock signal generator configured as shown in FIG. In this case, as shown in FIG. 4A, an adder 207 is provided between the low-pass filter 202 and the loop filter 203.

  Such a configuration has a drawback that the operating point of the phase detector is shifted. This is shown in FIG. That is, if the wobble / land pre-pit phase error signal is added as an offset to the wobble / recording clock phase error signal, the operating point of the phase detector is shifted. As a result, there has been a problem that the gain of the phase detector when the PLL is in stable operation changes, and as a result, the operation band of the PLL changes, and in some cases the PLL is disconnected.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to eliminate the influence of crosstalk from adjacent groove tracks without shifting the operating point of the phase detector.

  A data recording apparatus according to the present invention has a data recording track wobbled with a period related to a predetermined frequency, and a land-like pit having a predetermined phase relationship with the wobble of the recording track. A data recording apparatus for recording data on a recording medium, comprising: a generating means for generating a recording clock whose frequency changes in accordance with an input phase error signal; and a light beam for a recording track of the disc-shaped recording medium Irradiating means for irradiating, means for detecting the land pre-pit based on the reflected light of the light beam from the disc-shaped recording medium, and outputting a land pre-pit detecting signal, the land pre-pit detecting signal and the clock First phase difference detecting means for generating a first error signal indicating a phase error with the disk-shaped recording medium Second phase difference detecting means for generating a wobble signal related to the wobble period of the track based on the reflected light from the track and detecting a phase error between the wobble signal and the clock to generate a second error signal And multiplying the first error signal by the second error signal and outputting to the generating means as a phase error signal, and controlling the irradiation of the light beam by the irradiation means using the recording clock And means for recording data on the disc-shaped recording medium.

  The data recording method of the present invention comprises a data recording track wobbled with a period related to a predetermined frequency, and a disc-shaped disk on which land prepits having a predetermined phase relationship with respect to the wobble of the recording track are formed. A data recording method for recording data on a recording medium, wherein a generating step of generating a recording clock whose frequency changes according to an input phase error signal, and a light beam is applied to a recording track of the disc-shaped recording medium An irradiation step of irradiating; a step of detecting the land pre-pit based on the reflected light of the light beam from the disc-shaped recording medium; and outputting a land pre-pit detection signal; and the land pre-pit detection signal and the clock A first phase difference detecting step for generating a first error signal indicating a phase error with respect to the disk-shaped recording medium A second phase difference detecting step of generating a wobble signal related to the wobble cycle of the track based on the reflected light from the track, and detecting a phase error between the wobble signal and the clock to generate a second error signal And a multiplication step of multiplying the first error signal and the second error signal and outputting to the generation step as a phase error signal, and controlling irradiation of the light beam by the irradiation step using the recording clock And a step of recording data on the disc-shaped recording medium.

  A program according to the present invention has a data recording track wobbled at a period related to a predetermined frequency, and a disc-shaped recording medium on which land prepits having a predetermined phase relationship with respect to the wobble of the recording track are formed A program for causing a computer to execute a process of recording data on the recording medium, a generating process for generating a recording clock whose frequency changes in accordance with an input phase error signal, and a recording track of the disk-shaped recording medium. An irradiation step of irradiating a beam, a step of detecting the land pre-pit based on the reflected light of the light beam from the disc-shaped recording medium, and outputting a land pre-pit detection signal; and the land pre-pit detection signal; A first phase difference detecting step for generating a first error signal indicating a phase error with the clock; A wobble signal related to the wobble period of the track is generated based on the reflected light from the disc-shaped recording medium, and a second error signal is generated by detecting a phase error between the wobble signal and the clock. A phase difference detection step of the above, a multiplication step of multiplying the first error signal and the second error signal, and outputting to the generation step as a phase error signal, and light from the irradiation step using the recording clock And controlling the beam irradiation to record data on the disk-shaped recording medium.

  According to the present invention, when the phase modulation component is removed, the unit of the land pre-pit error signal is matched with the level of the phase detection signal between the wobble signal and the recording clock signal. As a result, the positional relationship between the groove track and the recording data can be accurately managed even when there is crosstalk from adjacent groove tracks.

(First embodiment)
Hereinafter, the overall configuration and operation of a data recording apparatus including a recording clock signal generator according to an embodiment of the present invention will be described with reference to FIG.
The data recording apparatus S of this embodiment includes a pickup 1, a spindle motor 2, a spindle driver 3, a laser drive circuit 4, a power control circuit 5, an encoder 6, a reproduction amplifier 8, and a reproduction signal decoder 9. And a processor (CPU) 10.

  Further, a target value generator 11 for generating a target value at the time of rotation control, a frequency difference detecting unit 12 for obtaining a difference between the target value of the target value generator 11 and the current rotation frequency, and a BPF (Band Pass Filter) 13. Further, a land pre-pit signal detector 14 as a land pre-pit detection means and a land pre-pit signal decoder 15 are provided. Further, it comprises an LPF (Low Pass Filter) 16 that functions as means for extracting the wobble signal by removing the land pre-pit LPP component, and a PLL (Phase Locked Loop) circuit 17.

  Among these, the band pass filter (BPF) 13, the land pre-pit signal detector 14, the LPF 16, and the PLL circuit 17 are the main components of the recording clock signal generator B in the present embodiment. The recording information data Srr to be recorded is input to the data recording apparatus S of the present embodiment from an external host computer (not shown) via the interface 7.

Next, the overall operation of the data recording apparatus S of this embodiment will be described.
The pickup 1 includes a laser diode, a polarization beam splitter, an objective lens, a photodetector, and the like that are not shown. During the recording operation, the information recording surface of the DVD-R 20 is irradiated with a light beam with an emission power that changes according to the laser driving signal based on the recording information data Srr supplied from the laser driving circuit 4. Recording information data Srr is recorded. In the reading operation, the DVD-R 20 is irradiated with a light beam with a constant emission power (reading power), and the reflected light is received by the photodetector.

  The data recording apparatus according to the present embodiment includes a data recording track wobbled by a wobble signal having a period (wobble period) related to a predetermined frequency, and has a land sample having a predetermined phase relationship with the wobble signal. Data is recorded on a disk-shaped recording medium on which pits are formed. In this embodiment, data is recorded on the DVD-R 20 based on a recording clock signal phase-synchronized with the wobble signal.

  Further, the pickup 1 irradiates the information recording surface of the DVD-R 20 with a light beam, and receives the reflected light from the information recording surface with a photodetector. Then, the received reflected light is converted into an electric signal, and an arithmetic processing based on, for example, a radial push-pull method is performed. As a result, a reproduction detection signal Sdt including the land prepit, groove track wobble signal, recording information data Srr and the like is generated and output to the reproduction amplifier 8. The reproduction amplifier 8 amplifies the reproduction detection signal Sdt that carries the land prepit signal of the land prepit and the wobble signal of the groove track output from the pickup 1.

  Then, the land prepit information signal Spp including the land prepit signal and the wobble signal is output to the BPF 13 in the recording clock signal generator B. In the reading operation, the amplified signal Srf corresponding to the recorded information data Srr already recorded is output to the reproduction signal decoder 9.

  The reproduction signal decoder 9 performs 8/16 demodulation and deinterleaving on the input amplified signal Srf, decodes the amplified signal Srf, generates a demodulated signal Sdm, and outputs the demodulated signal sdm to the CPU 10. To do. Here, the 8/16 demodulation employs a modulation / demodulation method called 8/16 modulation and 8/16 demodulation as a modulation / demodulation method for recording / reproducing information with respect to the DVD-R 20 of the present embodiment. This is a demodulation method that is performed.

  On the other hand, the BPF 13 functions as a composite signal extraction unit. Then, a noise component included in the land pre-pit information signal Spp supplied from the reproduction amplifier 8 is removed, and a composite signal Sppb in which the land pre-pit signal is superimposed at a predetermined position (for example, the maximum amplitude position) of the wobble signal (see FIG. 5 (see (a)). The extracted composite signal Sppb is output to the land pre-pit signal detector 14 and the LPF 16.

  The land pre-pit signal detector 14 functioning as the land pre-pit signal detecting means compares the composite signal Sppb with a predetermined reference value, for example, a level Vrp larger than the maximum amplitude unit of the wobble signal in FIG. , Comprising a comparator not shown. Then, in a period in which the amplitude level of the composite signal Sppb is larger than the reference value Vrp, a land prepit detection signal Slpp which is a pulse signal is generated in a period in which the land prepit exists. Then, the data is output to the land pre-pit signal decoder 15 and the PLL circuit 17. The PLL circuit 17 functions as a recording clock signal generation unit.

  The land pre-pit signal decoder 15 decodes pre-pit information including address information on the DVD-R 20 from the supplied land pre-pit detection signal Slpp, and outputs it to the CPU 10.

  On the other hand, the LPF 16 removes the land prepit component from the composite signal Sppb on which the land prepit is superimposed. This is because when the land pre-pit component is superimposed on the wobble signal, it becomes a noise source that deteriorates the jitter when generating the recording clock signal. As shown in FIG. 5B, an extracted wobble signal Swb from which the land pre-pit component has been removed is generated and output to the PLL circuit 17.

  The PLL circuit 17 includes an N counter 171, a COS wave generator 172, a SIN wave generator 173, multipliers 174, 176, 181, 182, LPF 175, 177, a phase comparator 178, a SIN / COS value converter 179, and an LPF 180. Have. It also has an adder 183, a loop filter 184, a VCO 185, and a lock detector 186, and outputs it as a recording clock signal Rclk to the encoder 6 and the power control circuit 5.

  On the other hand, the target value generator 11 outputs a signal level at which the VCO 185 is controlled as a target value at a rotation speed at which the spindle operates normally and the wobble has a target frequency.

  The frequency difference detection unit 12 detects the difference between the signal output from the target value generator 11 and the signal level that actually controls the VCO 185, and uses the detected signal as a rotation control signal via the spindle driver 3. Supply to the motor 2. Thus, a spindle servo is configured, and the DVD-R 20 is rotated at a predetermined rotational speed.

  On the other hand, the interface 7 performs an interface operation for taking in the recording information data Srr transmitted from a host computer (not shown) under the control of the CPU 10 into the data recording apparatus. Then, the recording information data Srr is output to the encoder 6 via the CPU 10.

  The encoder 6 uses the recording clock signal Rclk supplied from the PLL circuit 17 as a timing signal, performs ECC processing, 8/16 modulation processing, and scramble processing to generate a modulation signal Sdec and outputs it to the power control circuit 5 To do.

  The power control circuit 5 converts the waveform of the modulation signal Sdec (based on the recording clock signal Rclk output from the recording clock signal generator B) in order to improve the shape of the recording pits formed on the disc. A so-called write strategy process is performed. The waveform-converted signal is output to the laser driving circuit 4 as a recording signal Srec.

  The laser drive circuit 4 actually drives a laser diode (not shown) in the pickup 1 and outputs a laser drive signal for emitting a light beam with an emission power corresponding to the supplied recording signal Srec.

  The CPU 10 acquires address information from prepit information supplied from the land prepit signal decoder 15 when the data recording apparatus S of the present embodiment performs a recording operation. Then, the entire data recording apparatus S of the present embodiment is controlled so that the recording information data Srr is recorded at a position corresponding to the address information on the DVD-R 20.

  Further, when the data recording apparatus S of the present embodiment performs a reproducing operation, the CPU 10 acquires the recording information data Srr recorded on the DVD-R 20 from the demodulated signal Sdm. Then, the entire data recording apparatus is controlled so as to output the recording information data Srr to an external host computer.

  Next, a specific configuration of the recording clock signal generator B of the present embodiment will be described. The embodiment shown in FIG. 1 shows a specific example of a recording clock signal generator according to the present invention.

  The VCO 185 generates a recording clock signal Rclk. The reference frequency is a frequency with a period of 1T. Based on the recording clock signal Rclk, the N counter 171 operates the counter.

  By the way, the period of one sync frame in the DVD-R 20 corresponds to 1488 periods as indicated by the period of the recording clock signal Rclk, and corresponds to 8 periods as indicated by the period of the extracted wobble signal Swb. Therefore, the cycle of the extracted wobble signal Swb corresponds to 1488/8 = 186 cycles as indicated by the cycle of the recording clock signal Rclk.

  Accordingly, the counter output of the N counter 171 when “count value N = 185” is exactly the same as the cycle of the wobble signal Swb. Based on the output of the N counter 171, the COS wave generator 172 outputs a signal Scos (cosine signal component), and the SIN wave generator 173 outputs a signal Ssin (sine signal component (sine wave signal)). FIG. 6 shows the “count value N” of the N counter 171 and the waveforms during the operation of the signal Scos and the signal Ssin.

Here, the extracted wobble signal Swb is considered as a SIN wave,
Swb = ASin (w1t) (1)
Scos = Cos (w2t) (2) formula
Ssin = Sin (w2t) (3)

Therefore, the multiplier 174 functions as wobble / carrier multiplication means for multiplying the extracted extracted wobble signal Swb and the carrier signal having a predetermined phase relationship with the recording clock signal Rclk, and outputs Mcos. . The multiplier 176 functions as a wobble clock multiplying unit that multiplies the extracted wobble signal Swb and the signal Ssin in phase with the extracted wobble signal Swb, and outputs Msin. Therefore, these multipliers 174 and 176 function as second phase difference detection means for generating a second error signal. The second error signal has a sine signal component Msin and a cosine signal component Mcos. Where Mcos and Msin are
Mcos = 0.5ASin (w1t−w2t) + 0.5ASin (w1t + w2t) (4)
Msin = 0.5Acos (w1t−w2t) + 0.5Acos (w1t + w2t) (5)

Here, if w1 and w2 are close to each other, (w1t−w2t) is a low-frequency component close to DC (direct current), and (w1t + w2t) is a frequency that is almost twice the wobble frequency. Therefore, when the LPFs 175 and 177 are attenuated (w1t + w2t) and have a low-pass characteristic that allows (w1t−w2t) to pass, the output Misg of the LPF 175 and the output Mqsig of the LPF 177 are as follows. become.
Misig = 0.5ASin (w1t−w2t) = 0.5Asin (φ (t)) (6)
Mqsig = 0.5ACos (w1t−w2t) = 0.5Acos (φ (t)) (7)

  Here, Misig indicates a phase error signal between the wobble signal Swb and the signal Scos obtained by dividing the recording clock signal Rclk, and it can be seen that the LPF 175 functions as a phase detector. The output characteristics are as shown in FIG.

  Therefore, the output Misig of the LPF 175 is output to the loop filter 184, and the VCO 185 is operated by the output Fcont of the loop filter 184. As a result, a PLL loop is generated, and the recording clock signal Rclk synchronized with the wobble signal Swb can be output.

  However, as described above, the wobble signal component is phase-modulated due to the influence of crosstalk from adjacent groove tracks. The means for forming the PLL loop only for the phase-modulated wobble signal Swb cannot accurately manage the positional relationship between the groove track and the recording data.

  On the other hand, as described above, since the land pre-pit signal is not formed close to the radial direction of the DVD-R 20, it is not easily affected by crosstalk from adjacent land tracks. Therefore, compared to the wobble signal Swb, the land pre-pit detection signal Slpp can be regarded as an accurate timing signal that is not accompanied by fluctuation on the time axis based on crosstalk.

  In this embodiment, the phase comparator 178 detects the phase difference between the land pre-pit detection signal Slpp and the N counter 171 operating based on the recording clock signal Rclk. Therefore, the phase comparator 178 functions as a first phase difference detection unit that detects the first error signal. Here, the first error signal has a sine component signal and a cosine component signal. The configuration is such that the amount of phase modulation of the wobble signal component due to the influence of crosstalk from adjacent groove tracks is canceled.

Next, a specific configuration will be described with reference to FIG.
The phase comparator 178 compares the phase of the output of the N counter 171 operating based on the recording clock signal Rclk and the land pre-pit detection signal Slpp. Specifically, as shown in FIG. 7, the counter value Nval of the N counter 171 at the timing when the land pre-pit detection signal Slpp is detected is detected.

  In a situation where there is no influence of crosstalk from the adjacent groove track, the timing at which the wobble amplitude becomes the minimum value coincides with the detection timing of the land prepits. For this reason, the count value N of the N counter 171 synchronized with the wobble, for example, must be the same as the land pre-pit detection timing when “N = 140”.

  Therefore, with “N = 140” as the threshold value Tph, a difference value Ndiff between the threshold value Tph and the counter value Nval is detected and output to the SIN / COS value converter 179. This difference value Ndiff is the phase difference between the land pre-pit detection signal Slpp and the N counter 171 that operates based on the recording clock signal Rclk.

  The difference value Ndiff is a phase difference between the land prepit and the recording clock signal, and its unit is a recording clock signal unit. Therefore, in order to adjust the unit of the difference value Ndiff to the level of the phase detection signal between the wobble signal and the recording clock signal, the comparison result of the phase comparison means is converted into a periodic function. In this embodiment, a SIN / COS value converter 179 is used. For example, the SIN / COS value converter 179 has the same table as the COS wave generator 172 and the SIN wave generator 173.

  When the difference value Ndiff is input, the SIN / COS value converter 179 outputs the first phase error signal (first phase error) Plpps and the second phase error signal (second phase error) Plppc. Is done. FIG. 8 shows the relationship between the first phase error signal Plpps and the second phase error signal Plppc. Here, the first phase error signal Plpps corresponds to a phase error signal between the wobble signal Swb and the land pre-pit detection signal Slpp. Therefore, when this signal is added to the phase detection result of the wobble and the signal obtained by dividing the recording clock signal, that is, the output Misig of the LPF 175, as shown in Patent Document 1, it is shown in FIG. As described above, the output characteristics of the LPF 175 change. That is, the loop band of the PLL changes according to the detection result of the land pre-pit detection signal Slpp.

  Therefore, in this embodiment, the multipliers 181 and 182 and the adder 183 shown in FIG. That is, the output Misg of the LPF 175 and the first phase error signal Plpps are multiplied by the multiplier 181 (first multiplier). Further, the output Mqsig of the LPF 177 and the second phase error signal Plppc are multiplied by a multiplier 182 (second multiplier). Then, an adder 183 adds the output of the multiplier 181 and the output of 182. The output Misig of the LPF 175 and the output Mqsig of the LPF 177 are as shown in the equations (6) and (7).

Further, the first phase error signal Plpps and the second phase error signal Plppc, which are the outputs of the SIN / COS value converter 179, are expressed as Plpps = Sin (φ2 (t)), Plppc = Cos (φ2 (t)). Are multiplied by the output of LPF 175 and the output of 177, respectively. In this case, the output Misig_l of the multiplier 181 and the output Mqsig_l of 182 are:
Misig_l = 0.5ASin (φ (t)) × Cos (φ2 (t)) (8)
Mqsig_l = 0.5ACos (φ (t)) × Sin (φ2 (t)) (9)

The output Pherror of the adder 183 is
Pherror = Misig_l + Mqsig_l = 0.5ASin (φ (t) −φ2 (t)) (10) The characteristics at this time are shown in FIG.

  As can be seen from the comparison between FIG. 4 and FIG. 9, when the wobble / recording clock phase error signal and the wobble land pre-pit phase error signal are simply added, the output characteristics of the LPF 175 at the time of PLL lock change. It was. However, with the configuration as in the present embodiment, it is possible to prevent inconvenience that the characteristic at the operating point of the Pherro signal changes when the PLL is locked. That is, a stable PLL operation can be performed without changing the loop band of the PLL loop based on the wobble signal Swb.

  In FIG. 1, the output of the SIN / COS value converter 179 is output to the multipliers 181 and 182 via the LPF 180. This is because the output signal of the phase comparator 178 is converted in units of recording clocks, so that the fluctuation amount is large, and the operation of the PLL may be greatly shaken and the jitter may be increased. This is because the LPF 180 performs filtering.

  In FIG. 1, a lock detector 186 is provided. As shown in FIG. 2 described in Patent Document 1, land prepits LPP that become SYNC every 16 wobbles are superimposed at positions where the land prepits LPP are superimposed. Then, land pre-pits LPP are superposed at positions according to the address data.

  By the way, the actual output signal of the BPF 13 still has noise that cannot be removed by the BPF 13 and distortion of the wobble signal, and is likely to be erroneously detected by the land pre-pit signal detector 14. When an erroneously detected signal is input, the output signal of the phase comparator 178 increases jitter with respect to the PLL.

  In order to eliminate such inconvenience, after the PLL is locked, that is, after the phase difference is within a predetermined range for a predetermined period, a detection window is generated from the appearance pattern of the land prepit LPP to detect the land prepit LPP. It is desirable to do. For example, as shown in FIG. 10, it is desirable that the phase be detected only by the SYNC part of the land prepit LPP. As described above, the lock detector 186 is provided in order to perform phase detection after the PLL is locked.

Next, an example of the operation procedure of the data recording apparatus S of the present embodiment will be described with reference to FIG.
In the data recording apparatus S of the present embodiment, an example will be described in which data is recorded on a disk-shaped recording medium in which guide grooves are engraved spirally at a predetermined interval. In the disk-shaped recording medium, wobbles in which the guide grooves are slightly swelled along the guide grooves with a predetermined amplitude and period, and prepits having a predetermined phase relationship with the wobble signal are formed. An example will be described in which data is recorded on such a disk-shaped recording medium based on the multiplied clock signal while synchronizing with the wobble.
First, in step S111, information recorded on the DVD-R 20 is read to generate a reproduction detection signal Sdt. The reproduction detection signal Sdt includes land prepits, groove track wobble signals, recording information data Srr, and the like.

Next, in step S112, the land pre-pit information signal Spp is detected. The land pre-pit information signal Spp includes a land pre-pit signal and a wobble signal.
Next, in step S113, the noise component contained in the land pre-pit information signal Spp supplied from the reproduction amplifier 8 is removed. Then, a composite signal Sppb (see FIG. 5A) in which the land pre-pit signal is superimposed at a predetermined position (for example, the maximum amplitude position) of the wobble signal is extracted (step S113). The extracted composite signal Sppb is output to the land pre-pit signal detector 14 and the LPF 16.

  Next, in step S114, a land pre-pit detection signal Slpp, which is a pulse signal, is generated during a period in which the land pre-pit exists in a period in which the amplitude level of the composite signal Sppb is larger than the reference value Vrp. Then, the data is output to the land pre-pit signal decoder 15 and the PLL circuit 17.

Next, in step S115, a wobble signal Swb from which the land pre-pit component has been removed is generated, and an extracted wobble signal Swb is generated and output to the PLL circuit 17.
Next, in step S116, a phase error signal Misig between the wobble signal Swb and the signal Scos obtained by dividing the recording clock signal Rclk is generated and output to the loop filter 184.

Next, in step S117, land pre-pit system error extraction is performed. In the present embodiment, the first phase error signal Plpps and the second phase error signal Plppc are generated as the land prepit system error signals.
Next, wobble system error extraction is performed. In the present embodiment, a third phase error signal Misig and a fourth phase error signal Mqsig are generated as wobble system error signals.

Next, in step S119, the phase comparison result is converted into a periodic function so that the unit of the land pre-pit error signal matches the level of the phase detection signal between the wobble signal and the recording clock signal.
In step S120, the extracted wobble signal Swb is subjected to removal of phase modulation due to the influence of crosstalk from the adjacent groove track.

  By performing the above processing, the positional relationship between the groove track and the recording data can be accurately managed even when there is crosstalk from the adjacent groove track.

(Another embodiment according to the present invention)
Each means constituting the data recording apparatus in the above-described embodiment of the present invention can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable recording medium recording the program are included in the present invention.

  In addition, the present invention can be implemented as a system, apparatus, method, program, storage medium, or the like, and can be applied to a system composed of a plurality of devices. Moreover, you may apply to the apparatus which consists of one apparatus.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in FIG. 11) for executing each step in the above-described data recording method is directly or remotely supplied to the system or apparatus. In addition, this includes a case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  Various recording media can be used as a recording medium for supplying the program. For example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD- R).

  As another program supply method, a browser on a client computer is used to connect to an Internet home page. The computer program itself of the present invention or a compressed file including an automatic installation function can be downloaded from the homepage by downloading it to a recording medium such as a hard disk.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. Let It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer performs part or all of the actual processing. Also, the functions of the above-described embodiments can be realized.

  Further, the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instructions of the program, and the functions of the above-described embodiment are realized by the processing.

  Further, the program read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of the program, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

1 is a block diagram showing an overall configuration of a data recording apparatus including a recording clock signal generating apparatus according to a first embodiment of the present invention. It is a figure which shows an example of the mode of the track | truck in DVD-R20 of embodiment. It is a figure which shows an example of the block diagram used as the basis of the clock signal generator for recording. It is a block diagram at the time of applying a prior application to the circuit of FIG. It is a schematic diagram of a wobble signal and a land pre-pit signal in the first embodiment of the present invention. It is a relationship diagram of the counter and the generation | occurrence | production carrier in 1st Embodiment of this invention. It is a figure showing the relationship between the counter of the phase comparator 178 and the LPP in the first embodiment of the present invention. It is a figure which shows the mode of the signal output from the SIN / COS conversion table device in the 1st Embodiment of this invention. It is a schematic diagram of the output of the adder in 1st Embodiment of this invention. It is a figure showing the relationship between the wobble signal and the LPP phase detection window in the first embodiment of the present invention. It is a flowchart which shows embodiment of this invention and demonstrates an example of the procedure of a data recording method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pickup 2 Spindle motor 3 Spindle driver 4 Laser drive circuit 5 Power control circuit 6 Encoder 7 Interface 8 Reproduction amplifier 9 Reproduction signal decoder 10 Processor (CPU)
11 Target Value Generator 12 Frequency Difference Detection Unit 13 BPF (Band Pass Filter)
14 Land pre-pit signal detector 15 Land pre-pit signal decoder 16 LPF (Low Pass Filter)
17 PLL (Phase Locked Loop) circuit 20 DVD-R

Claims (10)

Data for recording data on a disk-shaped recording medium having a data recording track wobbled at a period related to a predetermined frequency and having land pre-pits having a predetermined phase relationship with respect to the wobble of the recording track A recording device,
Generating means for generating a recording clock whose frequency changes according to the input phase error signal;
Irradiating means for irradiating the recording track of the disc-shaped recording medium with a light beam;
Means for detecting the land pre-pit based on the reflected light of the light beam from the disc-shaped recording medium and outputting a land pre-pit detection signal;
First phase difference detection means for generating a first error signal indicating a phase error between the land pre-pit detection signal and the clock;
A wobble signal related to the wobble period of the track is generated based on the reflected light from the disc-shaped recording medium, and a second error signal is generated by detecting a phase error between the wobble signal and the clock. Phase difference detection means,
Multiplying means for multiplying the first error signal by the second error signal and outputting to the generating means as a phase error signal;
A data recording apparatus comprising: a means for controlling the irradiation of the light beam by the irradiation means using the recording clock to record data on the disk-shaped recording medium.   The first error signal has a sine component signal and a cosine component signal, the second error signal has a sine component signal and a cosine component signal, and the multiplying means has a sine of the first error signal. A first multiplier that multiplies a component signal and a sine component signal of the second error signal; and a second multiplier that multiplies the cosine component signal of the first error signal and the cosine component signal of the second error signal. The output of said 1st multiplier and the output of a 2nd multiplier are added, and it outputs to the said generation | occurrence | production means as said phase error signal. Data recording device. A counter for counting the recording clock;
The first phase difference detecting means detects a phase difference between the land pre-pit signal and the clock based on a count value of the counter at a detection timing of the land pre-pit signal, and a detection result of the phase difference The data recording apparatus according to claim 1, further comprising: a low-pass filter that performs a filtering process, and outputs an output of the low-pass filter as the first error signal.   The second phase difference detecting means includes means for generating a sine wave signal based on the recording clock signal, and a multiplier for multiplying the wobble signal and the sine wave signal. The data recording apparatus according to claim 1, wherein an output is output as the second error signal. Data for recording data on a disk-shaped recording medium having a data recording track wobbled at a period related to a predetermined frequency and having land pre-pits having a predetermined phase relationship with respect to the wobble of the recording track A recording method,
A generation step of generating a recording clock whose frequency changes according to the input phase error signal;
An irradiation step of irradiating the recording track of the disk-shaped recording medium with a light beam;
Detecting the land pre-pit based on the reflected light of the light beam from the disk-shaped recording medium, and outputting a land pre-pit detection signal;
A first phase difference detection step for generating a first error signal indicating a phase error between the land pre-pit detection signal and the clock;
A wobble signal related to the wobble period of the track is generated based on the reflected light from the disc-shaped recording medium, and a second error signal is generated by detecting a phase error between the wobble signal and the clock. The phase difference detection process of
A multiplication step of multiplying the first error signal and the second error signal and outputting to the generation step as a phase error signal;
A data recording method comprising: recording data on the disk-shaped recording medium by controlling irradiation of the light beam in the irradiation step using the recording clock.   The first error signal has a sine component signal and a cosine component signal, the second error signal has a sine component signal and a cosine component signal, and the multiplication step is a sine of the first error signal. The component signal and the sine component signal of the second error signal are multiplied by a first multiplier, and the cosine component signal of the first error signal and the cosine component signal of the second error signal are multiplied by a second. 6. The data according to claim 5, wherein multiplication is performed by a multiplier, and an output of the first multiplier and an output of the second multiplier are added and output to the generation step as the phase error signal. Recording method. A counter for counting the recording clock;
The first phase difference detection step detects the phase difference between the land pre-pit signal and the clock based on the count value of the counter at the detection timing of the land pre-pit signal, and the detection result of the phase difference The data recording method according to claim 5, further comprising: a low-pass filter that performs filtering, and outputting an output of the low-pass filter as the first error signal.   The second phase difference detection step includes a step of generating a sine wave signal based on the recording clock signal, and a step of multiplying the wobble signal and the sine wave signal by a multiplier. 6. The data recording method according to claim 5, wherein an output of a measuring device is output as the second error signal. A step of recording data on a disk-shaped recording medium having a data recording track wobbled at a period related to a predetermined frequency and having land prepits having a predetermined phase relationship with respect to the wobble of the recording track A program for causing a computer to execute
A generation step of generating a recording clock whose frequency changes according to the input phase error signal;
An irradiation step of irradiating the recording track of the disk-shaped recording medium with a light beam;
Detecting the land pre-pit based on the reflected light of the light beam from the disk-shaped recording medium, and outputting a land pre-pit detection signal;
A first phase difference detection step for generating a first error signal indicating a phase error between the land pre-pit detection signal and the clock;
A wobble signal related to the wobble period of the track is generated based on the reflected light from the disc-shaped recording medium, and a second error signal is generated by detecting a phase error between the wobble signal and the clock. The phase difference detection process of
A multiplication step of multiplying the first error signal and the second error signal and outputting to the generation step as a phase error signal;
A program for causing a computer to execute a step of recording data on the disc-shaped recording medium by controlling irradiation of a light beam in the irradiation step using the recording clock.   A computer-readable storage medium storing the program according to claim 9.

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