JPH04172623A - Rewritable recording medium and recording/reproducing unit - Google Patents

Abstract

PURPOSE:To realize correct identification of track number by employing lands as recording tracks and recording odd and even track numbers, respectively, in odd and adjacent even track areas in a pregroove. CONSTITUTION:Pregrooves 2 are made in the recording face of a rewritable recording medium, i.e. a rewritable optical disc 1. An address identifation signal comprises odd and even track number areas where odd track number is inserted into the odd track number area in a pregroove 2 holding an odd number track, i.e. a land 3, between whereas an even track number is inserted into the even track number area in a pregroove 2 holding an even number track, i.e. land 3, between. According to the constitution, track number can be identified correctly even if information is recorded at the land 3 of a rewritable disc having a pregroove carrying track identifying information including the track number.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a rewritable (including write-once) recording medium having a pregroove and a recording/reproducing apparatus thereof.

BACKGROUND ART A rewritable recording medium is known that has a curved pregroove to carry track identification information including a track number.

When recording information on a track of such a rewritable recording medium, or when reading recorded information, it is necessary to identify the track number. In conventional rewritable recording media, the same track number is recorded in the same group. The information to be rewritten is then recorded within the pregroove.

However, when information is recorded in the pregroove, since the flatness of the bottom of the pregroove is poor, noise may be mixed into the recorded information, resulting in a poor C/N ratio of the reproduced information signal.

Therefore, it may be possible to improve the C/N by recording the information to be recorded not on the pregroove but on a runt portion sandwiched between the pregrooves and having good flatness.

However, when recording on the land, the track number is identified from the pregrooves on both sides of the land, so
This creates a new problem as two different track numbers are read at the same time.

OBJECT OF THE INVENTION Therefore, an object of the present invention is to provide a rewritable recording medium that can identify the correct track number even if information is recorded on the land portion of the rewritable recording medium, which has a pregroove that carries track identification information including a track number. The object of the present invention is to provide a recording and reproducing device for the same.

Structure of the Invention A rewritable recording medium according to the present invention has a pregroove bent to carry one address identification signal for each unit information section, and uses a land portion as a recording track, the medium comprising: The address identification signal includes an odd track number area and an adjacent even track number area, and an odd track number is inserted into the odd track number area in a pregroove sandwiching a land portion that is an odd track. ,
Even number track numbers are inserted into the even number track areas in the pregreaves that sandwich the land portions that are even numbered tracks.

The recording/reproducing apparatus for a rewritable recording medium according to the present invention projects a reading spot onto the land portion, receives the reflected beam by at least two light receiving elements arranged in parallel in the track crossing direction, and receives the reflected beam from the two optical receivers of these light receiving elements. The present invention is configured to include an optical system for obtaining a converted output, and an extraction means that, when the track number in the converted output matches, sets the track number as the current track number.

Effects and Operations of the Invention In the rewritable recording medium and the recording/reproducing apparatus thereof according to the present invention, the bent pregroove has an odd numbered track number area and an adjacent even numbered track number area, sandwiching the land portion which becomes the odd numbered track. An odd track number is recorded in the odd track number area of the pregroove, and an even track number is recorded in the even track number area of the pregroove that sandwiches the land portion that becomes the even track. Then, during the period when writing or reading operations are performed on odd-numbered tracks, the odd-numbered track numbers in the odd-numbered track area are taken in, and during the period when writing or reading operations are performed on even-numbered tracks, the odd-numbered track numbers in the even-numbered track number area are taken in. The even track numbers are imported.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 9.

In FIG. 1, a pregroove 2 is provided on the recording surface of a rewritable optical disc 1 as a rewritable recording medium.

Land portions 3 sandwiched between pregrooves 2 are used as recording tracks, and information signals are recorded while forming bits 4 by irradiating a laser beam (not shown). In the case of a magneto-optical disk, bit 4 is recorded in the form of reversal of the magnetization direction.

The wall surface 5 of the pregroove 2 is bent in the direction perpendicular to the track. Therefore, due to this bent shape, the address identification signal, which is a wobble signal, which is a high frequency component, is superimposed on the traversing error signal, which is a low frequency component. This address identification signal is formed in a predetermined format in a unit information signal section called a sector.

As shown in FIG. 2, one sector has a 137-bit configuration. One track is divided into 25 sectors because it can be shared by NTSC and PAL when recording video format signals on a disc.

FIG. 2 shows the data array format of the sector including the track number among these 25 sectors. In this format, the 52-bit (6.5 bytes) clock pulse area CP has 1 clock pulse per 1 bit. A clock pulse train is recorded and serves as a PLL signal for the rotation servo when recording or reproducing the disk 1. Similarly, a 3-bit block synchronization signal is recorded in the area BS, and a 5-bit sector number (0 to 24) is recorded in the SN area. 6
The areas GP of 1 to 63, 98 to 100 and 135 to 137 bits are gaps, and are no-signal areas or unsteady wave areas.

The 18-bit area OTN from 64 to 81 is an odd track number area and is responsible for odd track numbers. The 18-bit area ETN from 119 to 134 is an even track area, and even track numbers are recorded therein. Error detection code pulses are recorded in the two redundant bit areas CRC.

In FIG. 3, a track number (hereinafter abbreviated) "1" is recorded in the pregroove areas OTH on both sides of track 1, no track number is recorded in the pregroove area ETN of one side, and “2” is recorded in the pregroove. Regarding track 2, one pregroove area OTN adjacent to track 1 has "1" as described above, and the other pregroove has "3".
It is recorded. Furthermore, in area ETN, "2" is recorded in both pregrooves on both sides.

In this way, the correct track number of the odd track [2n-1] (n is a natural number, the same applies hereinafter) is recorded in the pregroove area OTN on both sides, and the correct track number of the even track [2n-1] is recorded in the pregroove area OTN on both sides.
The correct track number is the pregroove area E on both sides.
Recorded in TN.

In FIG. 4, the spot 30 of the racer beam irradiated onto the land portion 3 is larger than the width of the land portion. The reflected beam of the spot 30 is irradiated onto a four-part light receiving element 31 shown in FIG. The output of the four-division light-receiving element 31 becomes the sum total or a read signal in the reproduction mode, and the two sum signals are supplied to the differential amplifier 32. Operating amplifier 32
The output is supplied as a tracking error signal to a tracking servo circuit (not shown) and also to a bandpass filter 33.

The output of the bandpass filter 33 is shaped into a waveform, and a wobble signal of a high frequency component included in the tracking error signal, that is, an address identification signal is extracted. Next, the address identification signal is sent to the clock recovery PLL circuit 34, the synchronization extraction timing circuit 35, and the high phase demodulation circuit 36.
is supplied to

The high phase demodulation circuit 36 outputs the sector number and track number described above, and the data register 37
and is supplied to the CRC check circuit 38. Here, the code data for error detection following the track number is supplied to the CRC check circuit 38, and it is determined whether the track number is correct or not.

The track number signals subjected to pi-phase modulation are consecutive odd track numbers, [2n-1].

[2n+1], [2n+3]... and consecutive even track numbers, [2n-2], [2n
], [2n+2]... The phases of the carrier waves are alternately inverted.

Therefore, the track numbers [2n-2co and [2n] in the area ETN of odd-numbered tracks (2n-1) in Fig. 3 are in opposite phase, and the reproduction amplitude cancels out and decreases, making it impossible to demodulate the data. First, the CRC check circuit 38 determines that it is an error. Similarly, the area OTN of even numbered tracks (2n)
The track numbers [2n-1] and [2n+1] are also determined to be errors.

In this way, odd numbered tracks (2n-1) and even numbered tracks (
2n), track numbers [2n-1] and [2n
n] is determined to be correct, and is output from the data register 37 as an address 1 separate signal. That is, even if information is recorded on the land portion of a rewritable or write-once recording medium, it is possible to identify the correct track number.

Next, a case will be described in which a video format signal is recorded on the rewritable optical disc 1 having a pregroove for carrying a track identification signal as described above.

The circuit shown in FIG. 6 is a processing circuit that inserts and records digital signals such as a video format signal and PCM audio data on the above-mentioned rewritable optical disc into the vertical blanking period of this video format signal, and plays the same. It is. In this processing circuit, an analog video format signal consisting of a luminance signal Y, color difference signals (RY), (B-Y), and a synchronization signal is inputted from the input terminal 6,
The A/D converter 7 converts the signal into a digital video format signal.

This digital video format signal is written to PIFO 8, which is a line memory, and subjected to time axis compression. The writing clock of the luminance signal to PIFO8 is 13.
5 Mt (z), the writing clock of the color difference signal is 2
．． 25 Mt(z). These clocks are given from the PLL clock generation circuit 9 to the read/write control circuit 10. The read clocks from the FIFO 8 are 16.2 MHz for both the luminance signal and the color difference signal.

Therefore, the luminance signal is 13.5(Mtlz)/16.2
(MHz), that is, 1/1.2. On the other hand, the color difference signal is 2.25 (MHz)/16.2 (MHz)
It is compressed to a ratio of 1/7.2. Furthermore, these three compressed video signals are time-axis multiplexed and
This results in two multiplexed video signals.

Next, the multiplexed video signal (well,
The frame (or field) memory 1 is processed through digital filtering (not shown) to remove aliasing noise.
Written to 1. In this frame memory 11,
Time adjustment (synchronization adjustment) is performed between the input multiplexed video signal and the multiplexed video signal recorded on the disk. The multiplexed video signal output from frame memory 11 is
The signal is read out in accordance with the synchronous clock of 1.6.2 M)lz in the recording mode, is supplied to the D/A converter 12, and is converted into an analog multiplex video signal.

Next, the analog multiplexed video signal is modulated in the FM modulation circuit 13, and the FM video signal is outputted via the selection circuit 14. This FM video signal, which is supplied to a laser diode (none of which is shown) in the drive section of the disk, is recorded as an information signal on the track of the land portion 3 in FIG. 1.

As mentioned above, during this recording, the track identification signal taken in from the pregroove 2 is transmitted to the identification signal decoder circuit 1.
5. Of the track identification signals, the clock pulse train or sector synchronization pulse train in the area CP in FIG. Given. Reading of the frame memory 11 is controlled in accordance with timing pulses output from the timing pulse generation circuit 17.

The controller 18 includes a CPU, POM, RAM, etc.
It receives the track number, sector number, etc. from the identification decoder 15 and controls the operation of the series of recording modes described above.

By the way, during the vertical blanking period of the FM video signal, the FM modulated signal of PCM audio data supplied from the input terminal 19 is inserted into the FM video signal through the selection circuit 14 and recorded.

In FIG. 7fa), one frame is divided into 25 sectors, sector 0 to sector 24, as described above. N.T.
The number of horizontal scanning lines (hereinafter referred to as lines) in one SC and PAL frame is 525 and 625. Therefore 1
If the frame is divided into 25, the number of lines in one sector of NTSC and PAL becomes 21 and 25, allowing the rewritable disc to be shared. In addition, the clock per line is 6.5 clocks for NTSC and 5.5 clocks for PAL, and even if the carrier component of the wobble signal leaks into the video signal band, the leakage frequency or 6.5 clocks of the line frequency fH will be affected. .5 and 5.5 times 0.5f
By shifting by +, the influence of leakage can be reduced.

Figure 7 (Field I is from sector 0 to the middle of sector 12, and field I is from the middle of sector 12.
It becomes. Therefore, the vertical blanking of one frame V
B is provided between sector O and between sectors 12 and 13. As shown in FIG.
Recorded in the period up to 4.

In FIG. 7 fc), during the vertical blanking VB, P
CM audio data is inserted and recorded.

Since the PCM audio data is recorded occupying the vertical blanking period in this way, the time code, which is the time information of the multiplexed video signal, is recorded at least in the synchronization pulse section, which is the IH run-in, other than the vertical blanking period. A clock pulse train signal for PLL synchronization is inserted into a synchronization pulse section including at least one line immediately after the vertical blanking period of the video format signal input from the input terminal 6 in FIG. The time codes are superimposed by, for example, bi-phase modulating the two clock signals using the time code. That is, the biphase modulation circuit 20 receives the time code and biphase modulates the clock pulse train of the multiplexed video signal output from the frame memory 11.

As shown in FIG. 8(a), the clock pulse train when the time coat is not modulated and superimposed is a pulse with a constant inversion interval, and PLL synchronization is achieved by this.

The modulated clock pulse train that has been subjected to pi-phase modulation according to the time code shown in FIG. 8 inputted to the high phase modulation circuit 20 is divided into "1" and "0" of the time code, as shown in FIG. 8 (C). The reversal interval changes based on.

However, the timing or phase of the edge of the modulated clock pulse train is the same as in the case of no modulation.

Therefore, time coats can be superimposed while maintaining the effect of PLL synchronization. If the number of "0"s in the time code increases, the number of edges for PLL synchronization will decrease, or because of the nature of the time code and the number of clock pulses (bits) will be large, there will be no problem with PLL synchronization.

In Figure 9 (J), the modulated clock pulse train is inserted into 80 bits or 2 areas PvICP for a total of 160 bits during one line period.If the same information is recorded in these 2 areas, errors may occur. They can be used for protection, or they can be used for different purposes by putting different information in them.A region ST is a start signal of a modulated clock pulse train.

A horizontal synchronization signal is inserted in area 5YNC. Further, the area REF represents the reference level of the video signal, and is the level of L1, L2, and L3, or the pedestal, color reference level, and white reference (white peak) level. Clock pulse trains for external synchronization are inserted into three areas AUX.

Figures 9 (b) and (C) are the last lines of the vertical blanking period of fields I and H, and the only difference is the time length of the horizontal synchronization signal and external synchronization clock pulse train. Field I and field H are identified by these different horizontal synchronization signals.

In Fig. 9, the multiplexed video signal of the effective line consists of 120 data samples each for the color difference signal and 7 data samples for the luminance signal.
There are 20 data samples.

When reproducing a disc on which PCM audio data and time code are recorded in a superimposed manner, a read signal read by an optical pickup (not shown) is amplified to a required level and supplied to the equalizer 21. The PCM data in the read signal output from the equalizer 21 is demodulated by a PCM data demodulation circuit 22, and then passed through a PCM reproduction circuit and an audio amplifier (none of which are shown) to reproduce the original audio signal.

On the other hand, the time code in the read signal is superimposed on i!
The video signal is supplied to an FM demodulation circuit 23 to obtain an analog multiplexed video signal.

This analog multiplexed video signal is subjected to A/D conversion, dropout compensation, etc., and then written to the frame (or field) memory 24. The multiplexed video signal whose time axis has been adjusted by the frame memory 24 is transferred to the FIFO
25, the time axis is expanded in the opposite direction to that during recording, and the original video format signal is finally output from the output terminal 26, but a detailed explanation will be omitted.

The modulated clock pulse train in the multiplexed video signal output from the frame memory 24 is demodulated by the biphase demodulation circuit 26 to obtain the original time coat.

Track numbers and the like obtained from the track separation signal during the reading operation are supplied from the identification signal decoder 15 to the controller 18 and utilized for control in the reproduction mode.

Incidentally, in the above embodiment, the modulation of the clock pulse train by the time coat is bi-phase modulation, but the present invention is not limited to this, and other modulation methods such as a one-round shift modulation method may be used.

Further, in the above embodiments, the recording medium is a rewritable optical disc, but it goes without saying that the present invention can also be applied to a write-once (CWO) type optical disc.

Effects of the Invention As described above, in the rewritable recording medium and recording/reproducing apparatus according to the present invention, the land portion is used as a recording track, and the odd track number and the adjacent even track number area of the pregroove are recorded. By recording even track numbers, during write or read operations on odd and even tracks, the track numbers of the odd and even track areas are captured and correct I/O is recorded.
- Rack numbers can be identified.

[Brief explanation of the drawing]

FIG. 1 is an enlarged perspective cross-sectional view of a rewritable optical disk which is a rewritable recording medium of the present invention, and FIG. 2 is a pregroove 2 shown in FIG.
FIG. 3 is an arrangement diagram recording the format of FIG. 2, FIG. 4 is a diagram showing the land portion of FIG. 1 irradiated with a light beam, and FIGS. 5 and 6 show the recording/reproducing apparatus of the present invention. Partial block diagrams, Figures 7(a) to C) and 9
Figure 8 is a timing chart showing the operation of a part of the block diagram of FIG. 6. Explanation of symbols of main parts 1 ...Rewritable optical disc 2 ... Pregroove 3 ... Land section 20 ... Biphase modulation circuit 26 ... Biphase demodulation circuit Applicant: Pioneer Co., Ltd.

Claims (5)

[Claims] (1) A rewritable recording medium having a pregroove bent to bear an address identification number of 1 for each unit information section, and using a land portion as a recording track, wherein the address identification signal is an odd track number area and this. An odd track number is inserted into the odd track number area in the pre-groove which includes an even track number area adjacent to the pre-groove which sandwiches the land area which becomes an odd track, and the even number track area in the pregreave which sandwiches the land area which becomes an even track. A rewritable recording medium characterized in that an even track number is inserted therein. (2) The rewritable recording medium according to claim 1, wherein the address identification signal includes a clock pulse region having a clock pulse train in addition to the odd and even track numbers. (3) The odd and even track numbers each include a carrier wave signal carrying a track number, and the carrier waves of consecutive odd track numbers are alternately in antiphase, and the carrier waves of consecutive even track numbers are alternately in antiphase. The rewritable recording medium according to claim 1, characterized in that: (4) an optical system that projects a reading spot onto the land portion and receives the reflected beam by at least two light receiving elements arranged in parallel in a track crossing direction to obtain two optical conversion outputs of these light receiving elements; A recording/reproducing apparatus comprising: extracting means for determining the track number as the current track number when the track numbers in the output match. (5) The extraction means includes demodulation means for bi-phase demodulating the converted output, and error detection means for detecting whether the track number obtained from the demodulation means is correct and outputting a positive track number. 5. The recording/reproducing apparatus according to claim 4.