JP2001014788A - Information recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information recorder capable of accurately recording the information to be recorded by controlling the recording operation while surely detecting an wobbling signal only, when the recording information is recorded on an optical disk whereon both of a land pre-pit and the wobbling signal are preliminarily recorded. SOLUTION: During the pre-pit detection for detecting the pre-pit signal in a pre-information signal SPP by a level detector based on the pre-information signal SPP including the wobbling signal SB outputted from a pickup, the pre- information signal SPP is changed over to the ground level to suppress a noise signal caused by the land pre-pit in the pre-information signal SPP, then by passing it through a band-pass filter BPF, the wobbling signal SB is extracted, then binarized to obtain the extracted signal SDTT for the rotational control of the optical disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital versatile disk (hereinafter, referred to as "CD") having a recording density which is significantly higher than that of a conventional compact disk (hereinafter referred to as "CD"). DV
It is called D. ), A write-once (Write Once, hereinafter, referred to as WO) type recording medium (hereinafter, DVD-R (DVD-Recordab)).
le). ), Address information or synchronization signal (hereinafter referred to as pre-information) necessary for position search or the like at the time of recording information such as an image, or rotation control information for controlling rotation of the DVD-R. The present invention relates to an information recording apparatus for reproducing pre-information from R and recording the information.

[0002]

2. Description of the Related Art Conventionally, as a recording medium on which information can be additionally recorded based on the above-mentioned pre-information, a CD-R (CD-Recordable) which is an optical disk having a recording capacity equivalent to that of a CD is known.
e) is known.

[0003] In a CD-R, pre-information is recorded in FM (Frequency) at a pre-formatting stage during manufacturing.
Modulation) The pre-information is recorded on the information track by wobbling the information track (groove track or land track) at the modulated signal frequency.

When information is recorded on the CD-R, the wobbling frequency of the wobbled information track is detected, and a reference clock for controlling the rotation of the CD-R is extracted based on the detected wobbling frequency. A drive signal for controlling the rotation of a spindle motor for rotating the CD-R is generated based on the reference clock.

Further, with respect to address information indicating an address on a CD-R necessary for recording information, pre-information is reproduced at the time of recording information, and a position to be recorded is detected based on the pre-information to record the information. I was

On the other hand, in a recently developed DVD-R, rotation control information is recorded on a groove track by, for example, wobbling the groove track at a frequency based on a reference clock for controlling the rotation of the DVD-R. Have recorded. In addition, the pre-information is recorded by forming land pre-pits on a land track between two groove tracks.

[0007]

The above DVD-R
When information is recorded on a groove track, for example, by irradiating a light beam onto a groove track to detect a signal including a wobbling frequency component of the groove track (hereinafter referred to as a wobbling signal), a signal adjacent to the center groove track is detected. Each of the land prepits on one land track is also irradiated with a part of the light beam. As a result,
In the wobbling signal detected from the center groove track, the signal corresponding to each land pre-pit on two adjacent land tracks is mixed as noise, which makes it impossible to detect a wobbling signal with good signal quality. there were.

Further, since the signal itself corresponding to the land prepit has an impulse characteristic (a characteristic in which the signal is uniformly distributed over the entire frequency band), the land prepit is not affected by the simple filter means alone. There is also a problem that the corresponding signal cannot be reliably removed.

In view of the above, the present invention has been made in view of the above-mentioned problems, and in which pre-information is recorded in land pre-pits and the wobbling signal is recorded, for example, the recorded information is recorded on a DVD-R. The present invention is to provide an information recording apparatus capable of controlling a recording operation and accurately recording information on a central groove track while reliably and accurately detecting the wobbling signal. .

[0010]

In order to solve the above-mentioned problems, the present invention provides an information recording apparatus having the following constitutions (1) and (2). (1) As shown in FIGS. 1, 2, 5 and 6, rotation control information (spindle servo control signal) for controlling the rotation of the recording medium (DVD-R) 1 (rotation control at a constant linear velocity) SSS is recorded by wobbling one track (groove track) 2 at a predetermined frequency (wobbling frequency) f0, and the one track 2
Position information indicating the upper position (address information or synchronization signal)
Is recorded (as pre-pits 4) on the other tracks (land tracks) 3 and 3 adjacent to both sides of the one track 2 respectively (as a pre-pit 4).
R) An information recording apparatus S for recording information on 1, wherein a light beam B is simultaneously irradiated on the one track 2 and the other tracks 3 and 3 adjacent to both sides of the one track 2, respectively. A pickup 10 for outputting a detection signal SDT based on the reflected light obtained thereby, and a reproduction signal (pre-information signal, push-pull signal, FIG. 4) based on the detection signal SDT output from the pickup 10.
(A)) When the wobbling signal SB is extracted from the SPP, and the position information components (noise components) SN1 and SN2 are mixed in the reproduction signal SPP, the position information is extracted from the reproduction signal SPP. A rotation control information output means (wobbling signal extraction unit) for outputting the rotation control information (spindle servo control signal) SSS by removing the components SN1 and SN2 and extracting the wobbling signal SB
Motor control means (servo circuit) for controlling the rotation of a motor (spindle motor) 14 for rotationally driving the recording medium 1 based on the rotation control information SSS outputted from the rotation control information output means 22 15. An information recording apparatus S comprising: (2) The information recording apparatus according to claim 1, wherein the rotation control information output means (22) removes the position information components (SN1, SN2) from the reproduction signal (SPP) when a predetermined amplitude range (upper limit level). amplitude range between l1 and lower level l2)
Are detected as the position information components SN1 and SN2, and an amplitude limited signal (limited pre-information signal) SPL is generated during which the amplitude of the reproduction signal SPP is substantially zero during this detection period. An information recording apparatus for extracting the wobbling signal SB from the limit signal SPL.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As will be described later, according to the present invention, one rotation control information (spindle servo control signal) SSS for controlling the rotation of a recording medium (DVD-R) 1 (rotation control at a constant linear velocity) is used. Is recorded by wobbling a track (groove track) 2 at a predetermined frequency (wobbling frequency) f0.
Position information (address information or synchronization signal) indicating the upper position
Is recorded (as pre-pits 4) on the other tracks (land tracks) 3 and 3 adjacent to both sides of the one track 2 respectively (as a pre-pit 4).
R) An information recording apparatus S for recording information on 1, wherein a light beam B is simultaneously irradiated on the one track 2 and the other tracks 3 and 3 adjacent to both sides of the one track 2, respectively. A pickup 10 for outputting a detection signal SDT based on the reflected light obtained thereby, and a reproduction signal (pre-information signal, push-pull signal, FIG. 4) based on the detection signal SDT output from the pickup 10.
(A)) When the wobbling signal SB is extracted from the SPP, and the position information components (noise components) SN1 and SN2 are mixed in the reproduction signal SPP, the position information is extracted from the reproduction signal SPP. A rotation control information output means (wobbling signal extraction unit) for outputting the rotation control information (spindle servo control signal) SSS by removing the components SN1 and SN2 and extracting the wobbling signal SB
Motor control means (servo circuit) for controlling the rotation of a motor (spindle motor) 14 for rotationally driving the recording medium 1 based on the rotation control information SSS outputted from the rotation control information output means 22 15. An information recording device S comprising: Further, according to the present invention, in addition to the above-described configuration, the rotation control information output means 22 outputs the position information component S from the reproduction signal SPP.
When removing N1 and SN2, a signal component outside a predetermined amplitude range (an amplitude range between the upper limit level 11 and the lower limit level 12) is detected as the position information components SN1 and SN2. An amplitude limiting signal (limited pre-information signal) SPL with the amplitude of the reproduction signal SPP being substantially zero is generated, and the wobbling signal SB is extracted from the amplitude limited signal SPL.

Next, a preferred embodiment of the present invention will be described with reference to the drawings. (I) Embodiment of recording medium First, a prepit corresponding to the above-mentioned pre-information as recording control information is formed, and a groove track described later is wobbled at a predetermined frequency to record rotation control information on the recording medium. As an example, a DVD-R will be described with reference to FIGS.

The structure of the DVD-R will be described. FIG.
Reference numeral 1 denotes a dye-type DVD-R provided with a dye film 5 and capable of writing information only once, and a groove track 2 as an information track, and a laser beam as a reproduction light or a recording light on the groove track 2. A land track 3 as an adjacent track for guiding the light beam B is formed. Also, a protective film 7 for protecting them.
And a gold vapor-deposited surface 6 for reflecting the light beam B when reproducing recorded information. Then, pre-pits 4 corresponding to pre-information (address information or synchronization information as position information of the groove track 2) are formed on the land track 3. This pre-pit 4 is a DVD-R
1 is formed before shipping.

In the DVD-R 1, the groove track 2 is wobbled at a frequency corresponding to the rotation speed of the DVD-R 1. The recording of the rotation control information by the wobbling of the groove track 2 is executed in advance before the DVD-R 1 is shipped, like the pre-pit 4.

When recording information (refers to information such as image information to be originally recorded other than pre-information and rotation control information; the same applies hereinafter) is recorded on the DVD-R1 having the above-described configuration. Groove track 2 in recording device
, The rotation control information is obtained to control the rotation of the DVD-R 1 at a predetermined rotation speed. At the same time, by detecting the pre-pits 4, pre-information is obtained in advance, and the optimum output of the light beam B as the recording light is set based on the pre-information. At the same time, address information or the like, which is the position on the DVD-R 1 where the recording information is to be recorded, is obtained, and the recording information is recorded at the corresponding recording position based on this address information.

At the time of recording the recording information, a light beam B is irradiated so that the center thereof coincides with the center of the groove track 2 to form recording information pits corresponding to the recording information on the groove track 2. To record the record information. At this time, the size of the light spot SP is set so that a part thereof is irradiated not only on the groove track 2 but also on an adjacent land track 3 as shown in FIG. Then, a push-pull method (a push-pull method using a photodetector divided by a dividing line parallel to the rotation direction of the DVD-R 1) using the reflected light of a part of the light spot SP applied to the land track 3 is used. Method (hereinafter referred to as a radial push-pull method)).
, The wobbling signal is detected from the groove track 2 using the reflected light of the light spot SP applied to the groove track 2, and a clock signal for rotation control is obtained.

Next, the recording format of the pre-information and the rotation control information pre-recorded on the DVD-R 1 will be described with reference to FIG. In FIG. 6, the upper part shows the recording format of the recording information,
The lower waveform shows the wobbling state (the plan view of the groove track 2) of the groove track 2 for recording the recording information. An upward arrow between the recording information and the wobbling state of the groove track 2 schematically indicates a position where the prepit 4 is formed. here,
The wobbling state of the groove track 2 is shown using an amplitude larger than the actual amplitude for easy understanding, and the recording information is recorded on the center line of the groove track 2.

As shown in FIG. 6, the recording information recorded on the DVD-R 1 is divided in advance into sync frames as information units. Then, one recording sector is formed by the 26 sync frames. Also, 16
One ECC (Error Correcti
ng Code) block is formed. One sync frame has a length of 1488 times (1488T) a unit length (hereinafter, referred to as T) corresponding to a bit interval defined by a recording format when recording the recording information. Further, synchronization information SY for synchronizing each sync frame is recorded in the first 14T length portion of one sync frame.

On the other hand, the pre-information recorded on the DVD-R 1 is recorded for each sync frame. Here, in the recording of the pre-information by the pre-pits 4, the land signal 3 adjacent to the area where the synchronization information SY in each of the sync frames in the recording information is recorded must always indicate the synchronization signal in the one pre-information as one. Two pre-pits 4 are formed. On the land track 3 adjacent to the first half of the sync frame other than the synchronization information SY, two or one pre-pits 4 are formed to indicate the contents (address information) of the pre-information to be recorded (note that the pre-pits 4). In the first half of the sync frame other than the synchronization information SY, the pre-pit 4 may not be formed depending on the content of the pre-information to be recorded.) At this time, in one recording sector, prepits 4 are formed only in even-numbered sync frames (hereinafter, referred to as EVEN frames) or only in odd-numbered sync frames (hereinafter, referred to as ODD frames), and pre-information is recorded. You.
That is, in FIG. 6, when the pre-pit 4 is formed in the EVEN frame (indicated by the solid line upward arrow in FIG. 6), the pre-pit 4 is not formed in the ODD frame adjacent thereto.

On the other hand, the groove track 2 has a constant wobbling frequency f0 of 140 kHz (a frequency corresponding to 8 waves per sync frame) over all sync frames.
Wobbling at. By detecting the wobbling frequency f0 in an information recording apparatus described later, a signal for controlling the rotation of the spindle motor can be detected.

(II) Embodiment of Information Recording Apparatus Next, an embodiment of the information recording apparatus according to the present invention will be described.
A description will be given based on FIGS. In the following description, an embodiment in which the present invention is applied to an information recording apparatus for recording digital information transmitted from a host computer on the DVD-R 1 will be described.

First, the overall configuration and operation of the information recording apparatus will be described with reference to FIG. In the following embodiment, a pre-pit 4 including address information and the like and a wobbling groove track 2 are formed on the DVD-R 1 in advance. At the time of recording digital information, the pre-pit 4 is detected in advance, so that the DVD-
It is assumed that address information on R1 is obtained, and a recording position on DVD-R1 where digital information is to be recorded is detected and recorded.

As shown in FIG. 1, the information recording apparatus S of the present invention comprises a pickup 10, a pickup 10 as a recording means, a reproducing amplifier 11, a decoder 12, a pre-pit signal decoder 13, and a spindle as a rotating means. Motor 14 and servo circuit 15 as movement control means
, A processor 16, an encoder 17, a power control circuit 18, a laser drive circuit 19, an interface 20, and a wobbling signal extracting unit 22 as information extracting means. Digital information SRR to be recorded is input to the information recording device S from an external host computer 21 via an interface 20.

Next, the operation of the entire information recording apparatus S of the present invention will be described. The pickup 10 includes a laser diode (not shown), a deflection beam splitter, an objective lens, a photodetector, and the like, and a light beam B based on a laser drive signal SDL.
Is irradiated onto the information recording surface of the DVD-R 1, the wobbling frequency of the prepit 4 and the groove track 2 is detected by the radial push-pull method based on the reflected light, and the digital information SRR to be recorded is recorded. If there is already recorded digital information, the already recorded digital information is detected based on the reflected light of the light beam B.

The reproduction amplifier 11 amplifies the detection signal SDT including the information corresponding to the wobbling frequency of the pre-pit 4 and the groove track 2 output from the pickup 10, and corresponds to the wobbling frequency of the pre-pit 4 and the groove track 2. The pre-information signal SPP is output, and the amplified signal SP corresponding to the already recorded digital information is output.

Thereafter, the decoder 12 decodes the amplified signal SP by subjecting the amplified signal SP to 8-16 demodulation and deinterleaving, and outputs a demodulated signal SDM and a servo demodulated signal SSD.

On the other hand, the pre-pit signal decoder 13 extracts only a signal obtained by detecting the pre-pit 4 included in the pre-information signal SPP and decodes the extracted signal.
The corresponding demodulated pre-pit signal SPD is output. And
The servo circuit 15 outputs a pickup servo signal SSP for focus servo control and tracking servo control in the pickup 10 based on the demodulated pre-pit signal SPD and the servo demodulated signal SSD. Further, the servo circuit 15 outputs the extracted signal SDTT based on the extracted signal SDTT.
The spindle servo control signal SSS is output using the information corresponding to the wobbling frequency f0 included in the TT to servo-control the rotation of the spindle motor 14.

On the other hand, the interface 20 performs an interface operation for taking in the digital information SRR transmitted from the host computer 21 into the information recording device S under the control of the processor 16,
The digital information SRR is output to the encoder 17. The encoder 17 includes an ECC generator (not shown), an 8-16 modulator, a scrambler, and the like. The encoder 17 constitutes the ECC block, which is a unit for performing error correction during reproduction, based on the digital information SRR. , And performs interleaving, 8-16 modulation, and scrambling to generate a modulated signal SRE.

Thereafter, the power control circuit 18 outputs a recording signal SD for controlling the output of a laser diode (not shown) in the pickup 10 based on the modulation signal SRE. Further, the laser drive circuit 19 outputs a laser drive signal SDL for actually driving the laser diode to emit the light beam B based on the recording signal SD.

On the other hand, the wobbling signal extractor 22 extracts only the wobbling frequency of the groove track 2 included in the pre-information signal SPP, and outputs the extracted signal SDTT to the servo circuit 15. Finally, the processor 16 obtains pre-information using the demodulated pre-pit signal SPD input, and obtains digital information S corresponding to the position on the DVD-R1 corresponding to the address information included in the pre-information.
Controls the operation of recording RR. In parallel with these, the processor 16 outputs a reproduction signal SOT corresponding to the already recorded digital information to the outside based on the demodulated signal SDM, and mainly controls the entire information recording apparatus S.

The information recording device S is a DVD-ROM.
It is also possible to reproduce the information recorded in R 1, in which case the processor 1 is operated based on the demodulated signal SDM.
The reproduction signal SOT is output to the outside through the line 6.

Next, a detailed configuration of the wobbling signal extraction unit 22 according to the present invention will be described with reference to FIGS.

As shown in FIG. 2, the wobbling signal extracting section 22 outputs the pre-information signal SPP (the signal corresponding to the wobbling frequency of the groove track 2 to the land pre-pit 4
Is detected, a land pre-pit signal period for removing the signal corresponding to the land pre-pits 4 from the pre-information signal SPP is detected, and the amplitude fluctuation of the pre-information signal SPP is limited. And the restricted pre-information signal S
An amplitude switch 26 for outputting a PL and a limited pre-information signal SPL
BPF (Band Pa) that removes the high-frequency component included in the restricted pre-information signal SPL and outputs a wobbling signal SB corresponding to the wobbling frequency of the groove track 2.
ss Filter) 27 and a binarizer 28 that binarizes the wobbling signal SB and outputs an extracted signal SDTT.

Further, as shown in FIG.
Are a comparator for detecting the land pre-pit period of the pre-information signal SPP, and an F for switching the amplitude of the pre-information signal SPP to the ground level only during the land pre-pit period.
It comprises an ET (field effect transistor) and an FET driver.

Next, the operation of the wobbling signal extracting section 22 will be described with reference to FIG. As described above, the pre-information signal SPP input to the wobbling signal extraction unit 22
As shown in FIG. 4A, in addition to a frequency component (low-frequency pulsation component) corresponding to the wobbling frequency of the groove track 2, a high-frequency component (high-frequency pulsation component) that is noise at the time of detection And a noise signal caused by the land pre-pit 4 (impulse components indicated by reference signs SN1 and SN2)
It is included. Among them, the noise signal SN1 is a noise signal caused by the pre-pit 4 on the land track 3 adjacent to the groove track 2 to which the light beam B was irradiated when the pre-information signal SPP was detected. On the other hand, the noise signal SN2 is a noise signal caused by the pre-pits 4 on the land track 3 located on the opposite side of the land track 3 where the pre-pits 4 causing the noise signal SN1 exist with respect to the groove track 2. . These noise signals SN1 and SN2 have an impulse characteristic in which the signals are uniformly distributed over the entire frequency band as described above.

Therefore, the wobbling signal extraction circuit 22
Switches the amplitude of the pre-information signal SPP to the ground level only during the land pre-pit signal period in order to remove the signal corresponding to the land pre-pit 4 from the pre-information signal SPP. After that, the limited pre-information signal SPL in which the noise signals SN1 and SN2 have been attenuated is input to the BPF 27, the high-frequency component is removed, and a wobbling signal SB (FIG. 4E) is output. The extracted signal SDTT is output to the servo circuit 15 as an extracted signal SDTT (FIG. 4 (F)), and is subjected to spindle servo control by detecting a period of transition between two values in the extracted signal SDTT.

The reason why the wobbling signal SB is obtained by using the BPF 27 after switching the level of the pre-information signal is that the pre-information signal SPP is
If the signal is input to F27, the noise signals SN1 and SN2 cannot be sufficiently removed due to the wide band characteristics of the noise signals SN1 and SN2, so that the upper limit signal SUL and the lower limit signal SUL are not removed.
The configuration is such that the energy of the noise signals SN1 and SN2 is attenuated by WL and then input to the BPF 27.

As described above, according to the information recording apparatus S of the above-described embodiment, only the wobbling signal SB is extracted from the pre-information signal SPP to record the digital information SRR. Even in the DVD-R1 on which the DVD-R4 is formed, the digital information SRR can be recorded by accurately controlling the rotation speed of the DVD-R1 based on the extracted wobbling signal SB.

FIGS. 4B and 4C show land pre-pit detection signals SF1 and SF2, and FIG. 4D shows pre-information signal Spp as land pre-pit detection signals SF1 and SF2.
3 shows a signal after switching to the ground level only during the high period. FIG. 4E shows the signal SB after passing the signal Spl through the BPF 27.

[0040]

As described above, according to the present invention,
For example, when pre-information is recorded by land pre-pits and wobbling signals are recorded, for example, when recording information is recorded on a DVD-R, only this wobbling signal can be reliably detected. And the recording information can be recorded accurately. Also, by limiting the level of the reproduction signal only when there is position information using the amplitude restriction signal, the signal corresponding to the position information is removed from the reproduction signal, and only the wobbling signal is extracted to record the information. Thus, it is possible to reliably extract the rotation control information of the motor.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an information recording apparatus according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a wobbling signal extraction unit.

FIG. 3 is a diagram showing a configuration of an amplitude switch.

FIG. 4 is a timing chart illustrating an operation of a wobbling signal extraction unit.

FIG. 5 is a diagram illustrating a configuration of a DVD-R.

FIG. 6 is a diagram illustrating a recording format in a DVD-R.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 DVD-R (recording medium) 2 Groove track (one track) 3 Land track (the other track) 10 Pickup 11 and 12 Level 14 Spindle motor (motor) 15 Servo circuit (motor control means) 22 Wobbling signal extraction part ( Rotation control information output means) B light beam f0 wobbling frequency (predetermined frequency) S information recording device SDT detection signal SN1, SN2 noise component SPL restriction pre-information signal (restriction information signal) SPP pre-information signal SSS spindle servo control signal (rotation) Control information)

Claims (2)

[Claims] 1. Rotation control information for controlling the rotation of a recording medium is recorded by wobbling one track at a predetermined frequency, and position information indicating a position on the one track is recorded on the one track. What is claimed is: 1. An information recording apparatus for recording information on a recording medium having a structure recorded on the other track adjacent to both sides, comprising: the one track and the other track adjacent to both sides of the one track. Simultaneously irradiating the light beam respectively, and a pickup that outputs a detection signal based on the reflected light obtained thereby, while extracting the wobbling signal from a reproduction signal based on the detection signal output from the pickup,
When the position information component is mixed in the reproduction signal, the rotation control information output for outputting the rotation control information by removing the position information component from the reproduction signal and extracting the wobbling signal. An information recording apparatus comprising: means for controlling rotation of a motor for rotationally driving the recording medium based on the rotation control information output from the rotation control information output means. . 2. The information recording apparatus according to claim 1, wherein the rotation control information output means removes the position information component from the reproduction signal.
A signal component outside a predetermined amplitude range is detected as the position information component, and an amplitude limit signal is generated in which the amplitude of the reproduction signal is substantially zero during the detection period. The wobbling signal is generated from the amplitude limit signal. An information recording device, characterized by extracting information.