CA1325274C - Recording medium and recording and reproducing apparatus employing the recording medium - Google Patents
Recording medium and recording and reproducing apparatus employing the recording mediumInfo
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- CA1325274C CA1325274C CA 603254 CA603254A CA1325274C CA 1325274 C CA1325274 C CA 1325274C CA 603254 CA603254 CA 603254 CA 603254 A CA603254 A CA 603254A CA 1325274 C CA1325274 C CA 1325274C
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Abstract
ABSTRACT
According to this invention, a recording medium has a recording track comprising first portions alternating at regular intervals with second portions, wherein the recording track has substantially constant width along each of the first portions and changing width along each of the second portions. The changing width along each of the second portions determines a set of a predetermined number of control data bits, and each the set of the predetermined number of bits determines address data for a different data block.
According to this invention, a recording medium has a recording track comprising first portions alternating at regular intervals with second portions, wherein the recording track has substantially constant width along each of the first portions and changing width along each of the second portions. The changing width along each of the second portions determines a set of a predetermined number of control data bits, and each the set of the predetermined number of bits determines address data for a different data block.
Description
Recording Medium and Recording and Reproducina Apparatus Employin~ the Recording l~edium BACKGROUND OF THE INVENTION
Field of the Invention This invention relates to a recording medium, a recording apparatus and a reproducing apparatus employing the recording medium, that may be employed in a data storage system.
Prior Art There are a variety o~ diffarent types of apparatus for recording and reproducing data on a recording medium, operatin~ on various r~cording/reproducing principles or utilizing recording media having various outer shapes.
In general, data recording media can be classified according to the operating principle, such as the magnetic and/or optical re~ording/reproducing principle, and also according to the oute~ shape, such as tape, card, or disc shaped recording media.
For example, there are disc players dedicated to reproduc~ion, such as CD pLaysrs for reproducing a so-called compact-disc (CD) on which audio signals such as voice or musical sound are previously recorded in a digitized form.
In a compact disc tCD), as shown in Fig. ~ a data format ha~ing 98 frames as one subcode biock is standardi æ d, wherein each ~rame is constituted by a 24-bit sync signal, given as eight to fourteèn modulation data, in which 1-symbol/8-bit signals are converted into data of 14 bits (L channel bit) constituting 1 symbol of subcode, i.e. one symbol being composed of 14 bits, 32 symbols o~ data, such as two sets of 12 symbols of play data and 4 symbols of parity bits, with each symbol being composed of 14 x 32 bits, and with three merging ., .~
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Field of the Invention This invention relates to a recording medium, a recording apparatus and a reproducing apparatus employing the recording medium, that may be employed in a data storage system.
Prior Art There are a variety o~ diffarent types of apparatus for recording and reproducing data on a recording medium, operatin~ on various r~cording/reproducing principles or utilizing recording media having various outer shapes.
In general, data recording media can be classified according to the operating principle, such as the magnetic and/or optical re~ording/reproducing principle, and also according to the oute~ shape, such as tape, card, or disc shaped recording media.
For example, there are disc players dedicated to reproduc~ion, such as CD pLaysrs for reproducing a so-called compact-disc (CD) on which audio signals such as voice or musical sound are previously recorded in a digitized form.
In a compact disc tCD), as shown in Fig. ~ a data format ha~ing 98 frames as one subcode biock is standardi æ d, wherein each ~rame is constituted by a 24-bit sync signal, given as eight to fourteèn modulation data, in which 1-symbol/8-bit signals are converted into data of 14 bits (L channel bit) constituting 1 symbol of subcode, i.e. one symbol being composed of 14 bits, 32 symbols o~ data, such as two sets of 12 symbols of play data and 4 symbols of parity bits, with each symbol being composed of 14 x 32 bits, and with three merging ., .~
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bits between the adjacent .symbols. Thus each frame - includes the sum total of ~88 bits. The absolute address of each subcode bl~ck i8 given by the Q-channel signals of the abov~ subcode and the data such as the play data are processed at intervals o~ one s~bcode block.
` In CD-ROMs, as shown in Fig. 2, the le~t and right ~hannel digital audio sign~ls recorded on the compact ~isc (CD) are alternately ~nnected at intervals of one .
lo word (2 8ymbols ~ 16 bits) ~D as to be treated as one channel of serial data and the CD is treated as a data storage device, a header sPction and sync signals are : ' annexed ahead of each subcode block or 98-frames of : ;
data in the CD data format, such that each sector or block is constituted by 2X bytes of data.
Since the conventional CD player is dedicated to reproduction, attempts have been made to develop a data - stora~e medium and the recording and/or reproducing system making use of the data çtorage medium, such as a 80 called "write once compact disc" (referred to as a - "CD-Wo") or an erasable compact disc ~re~erred to as "CD-erasable"). This CD-WO or CD-erasable makes use of a magneto-optical disc which is formed by a rewritable ....
magneto-optical recording medium and which is .
interchangeable with respect to the CD or CD-erasable, as disclosed in EP application No. 0265695 published on ; May 4, 1988.
In the data recording/reproducing system making use of a recording medium such as the CD-WO o~ CD-erasable, it is necessary to control data efficiently on a block-by-block basis. However, in the CD data format, there are only a few address data, such that, when the data format is used in a data storage medium such as CD-WO or , . ~ ~
~ 325274 CD-erasable, it is difficult to control the data on a block-by-block basis.
OBJECTS AND SUMMARY OF THE INVENTIO~
It is a principal object of the present invention to provide a data recording/reproducing system wherein data can be controlled efficiently on a block-by-block ba~
It is another ob~ect of the pr~sent invention to ~vide a recording medium ~herein ~ata can be controlled efficiently on a ~lock--by-block basis.
It is a further object of the present invention to provide a recording medium wherein interchangeability can be maintained with the CD or the CD-ROM.
It is a further object of the present invention to provide a recording apparatus and a reproducing apparatus wherein data can be controlled efficiently on a ~lock-by-block basis.
It is yet another object of the present invention to provide a data recording apparatus which can cope with the case of recording in a continuous recording mode, as when recording musical data, or CD-ROM
recording data, and which can utilize the address on the disc in the intermittent recording mode to provide for high speed accessing of recording/reproducing data for each sector as when using the apparatus as a C~-WO or as a CD-erasable.
The above and other objects of the present invention are attained by a recording medium having a recording track whose width is changed in a burst-like fashion to represent control data of a predetermined number of bits. The control data are the address data for each data block as one unit. The regions containing widthwise changes of the track, and thus including the address data, represent data record - . ~
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,,,, . -regions or data non-record regions depending on the recording mode, which can be either a modQ ~n which the recorded data are sub~ected to convolution encoding or a mode in which the recorded data are subje¢ted to sector S complete type encoding.
In still another embodiment of the invention, the recording medium has a recording track whose centerline i8 periodically displaced acros the track width with respect to an imaginary centerline of the recording track. The track width also changes in a burst-like fash~on, wherein period data are pre-recorded by the deviation of the track centerline across the track width and control data of a predetermined number of bits are represented by the ~urst-like changes of the track width.
The invention further includes an apparatus for recording data on such a recording medium and including detecting means for detecting the control data signals recorded on the recording trac~, the detecting means including two pairs ~f detectors, each pair being arranged across the tracX width and producing a separate push-pull output, and control means for controlling the data recording operation on the recording track based on the control data. The control data are address data and the control means controls the recording on the recording track based on the -' reproduced address ~gnal~. When the recor~ing medium has a recording track whose centerline i8 periodically displaced across the track width with respect to an imaginary centerline of the recording track, then the detecting means detec~s the period data as well as the control data and the control means controls the recording operation ~n the recording track based on the period data and the control data as represented by the push-pull outputs of the detecting means.
The above and other objects of the present invention will become more apparent upon reading the following description in conjunction with the accompanying drawinge.
s BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagrammatic view showing the data format of a compact disc (CD);
Fig. 2 is a diagrammatic view showing the data format of a CD-RO~;
Fig. 3 is a diagrammatic plan view showing an optical disc as the recording medium according to a ! first embodiment of the present invention together with t an enlarged detail view of three of the radial trac~s thereon;
Fig. 4 is a diagrammatic view showing an arrangement of an optical pickup adapted for reading data on the optical disc depicted in Fig. 3;
Fig. 5 is a diagrammatic yiew showing the data recording state on the recording track of the optical disc:
Fig. 6 is a block diagram showing an arrangement of a recording/reproducing apparatus employing th~ optical disc of the first embodiment as the recording medium;
Fig. 7 is a diagrammatic plan view of an optical disc as the recording medium according to a seaond embodiment of the present invention;
Fig. 8 i~ a block diagram showing the recor*ing /reproducing apparatus employing the opticai disc of the second embodiment as the recording medium; and Fig. 9 i8 a waveform diagram for illustrating the operation of the recording/reproducing apparatus.
1$fi5EIilIQN OF THE PREFERRED EMBODI~
~eferring to the drawings, certain illuqtrative embodiments of t~e present invention will be explained in more detail.
Referring now to Fig. 3 wherein all or part of the optical disc as the recording medium according to a ~irst embodiment of the present invention is ~iagrammatically æhown, a magneto-optical disc is ~ployed as the ~p~ical disc 1 in which a ~rpendicularly ~gnetized film having magneto-optical effects is formed on a transparent base plate. The lands sandwiched between the spirally formed pregrooves s 2 are formed as the recording track 3 and the block data completed by 2K bytes of data in accordance with the above described CD-ROM data format are photo-magnetically recorded on the recording track 3. A long portion of the length of the spiral track 3 constitutes the data region 6 where data are recorded.
In the recording track 3, address regions 4 are provided at equidistant positions along the length of the track 3 corresponding to the sync aignal (SYNC) portion or to the error correction code (ECC) portion in the above CD-ROM data format. Each address region 4 represents burst-like changes across the track width whereby 19-bit address data, for example, are pre-recorded in each address region 4. The signal spectrum of the address data produced by the changes across the track width is selected to represent a co~ponent higher than that of the frequency spectrum of the servo region.
Radially interior from the data region 6 there is formed a lead-in region 7, in which there are recorded lead-in data indicating the recording state of the data region 6.
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In the optical disc 1 ~f the first embodiment of the invéntion there are recorded in each address region 4 address data of a predetermined bit number by the changes acros~ the track width. As shown in Fig. 4, a four segment detector 10 composed of four photodetectors A, B, C and D is used in conj~nction with a laser light source (not shown) as a data read-out optical pickup.
Thus, a data signal RF can ~.e detected in the ~orm of a summation output signal S~ ~ SB ~ 8c + SD obtained by summing the outputs SA, Sg, S~, and SD of t~e respectivc detectors A, B, C and D at an adder ll. On the other hand, an address information signal ADR can be detected ,~ in the form of a subtraction output signal equal to tSA
~ Sg) - (Sc + SD) obtained by subtracting in a subtractor 14 a summation output (Sc + SD) of the outputs Sc and SD of the detectors C and D produced by an ad~er 13 from a s~mmation output (SA + Sg) produced by an adder 12 of the Dutputs SA and SB of the detectors A and B, wherein the ~etectorssA, B and C, D are arranged in the longitudinal or X - X' direction of the recording track 3, that is, in the form of push-pull output~ SA - SD and Sg - Sc, and the detectors A, D and B, C are arranged in.the widthwise direction or Y - Y~
. direction of the recording track 3.
The address information ADR does not substantially affect the data signal RF. Thus, as shown in ~ig. 5, the ~ta recordlng region 5 can be extended up to and thrcugh the address region 4 of the recording track 3.
In the above described optical disc 1~, the address regions 4 are provided at predetermined intervals along the l~ngth of the signal track 3, wherein the address information o~ the signal spectrum above the servo regian is indicated as changes across the track width, so that the block data completed by 2K bytes of data in accordance with the CD-ROM data format can be recorded .: - --on or reproduced from the recording track 3 on the basis of the above address information without the tracking servo or focusing servo for the recording track 3 being disturbed by the address in~ormation or data.
Data recording can be made in two modes on the optical disc 1. one of such modes is that for the above described continuous recording. This mode for continuous recording is convenient for direct recording of CD-ROM data or of sequential data, such as musical data.
In this continuous recording mode, there is no time period which is devoid of data, so that, as shown in s Fig. 5, the pits 5 are also formed in the address region 4, which is used simultaneously as the data record region.
The other mode i8 the mode for intermittent recording, which is convenient for recording data at randomly selected addresses, as in the case o~ CD-WO or CD-erasable. ~
The basic data structure for such an intermittent recording mode is similar to that for continuous rding except that the 12-byte sync signals for musical signal blocking in the data format shown in Fig.
2 are not provided for in the intermittent record mode, in which data are recorded with a 98 frame sect~r as one recording unit. In each of these sectors,~there are recorded the same dat~ as those of the data format shown in Fig. 2 except the 12-byte sync signals Sor blocking the musical signals.
Thus, in the intermittent recording mode, a vacant region equivalent to 12 bytes can be procured in each sector having a total data capacity of 2352 bytes. This 12-byte vacant region corresponds to the address region 4.
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g Therefore, when data are recorded in the intermittent record mode, no data are recorded in the address regions 4, so that the address data recorded in the address regions are left over a~ter data recording.
Thus, the address information recorded in the address regions 4 can be resorted to for seeking desired sectors.
In the intermittent recording mode, the encoding co~ple~ed in each sector is used instea~ of convolution e~coding. Encoding complete in each sector can be realized by a method described in, for example, the Japanese Patent Application No. 118567/1988. The merging bit at the time of recording with EFM modulation is reset at each sector.
Fig. 6 shows diagrammatically the digital data recording/reproducing apparatus to which the present invention is applied. This apparatus is designed to record or reproduce digital da~ optically by using the optical disc 1 shown in Fig. 3~as the recording medium, and is provided with a recording circuit 110 and a reproducing circuit 120.
The optical disc 1 is pro~i~ed with the above described address regions 4 in each of which ar~
recorded physical address data as burst-like changes of the track width. The disc 1 performs a revolution at a constant linear velocity (CLV3.
The recording circuit 110 can be set to the above described continuous record an~ intermittent record modes responsive to select signals from the terminal 114.
The 12-byte sync signals are provided in each sector for the continuous record mode but are not provided for in the intermittent record mode.
During recording, data to be recorded on the optical disc 1 are supplied from a data input terminal - .~
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111 to an encoder 112 of the recording circuit 110. The address of the optical disc 1 can be obtained from the address information recorded in the address information 4 80 that a desired address can be souqht to record the data therein. The data from the data input terminal 111 are developed in the encoder 112 into a predetermined frame structure for annexing duplex error correction codes of the Cl and C2 series. This encoding is by the convolution encoding ~or continuous record mode and by the sector-complete encoding for the intermittent record mode. The data to which the duplex error correction codes are annexed at the encoder 112 are eight to fourteen modulated at the EFM circuit 113 so as to be t recorded in the sector of the optical disc 1 bearing the desired address.
In the continuous record mode, data are recorded in the address regions 4 provided on the optical disc 1.
Conversely, in the intermittent r~cord mode, no data are recorded in the address region~ 4 of the optical disc 1 so that the address data recorded in these address regions 4 as the burst-like changes of the track width remain unaf~ected.
The data recorded on the disc 1 can be reproduced by a sequence which is the reverse of the above described sequence adopted for recording.
Thus, the above described continuous reco~d or interm~tt~nt modes can be set in the reproducing ci~;t 120 depending on the select signals from the terminal 124.
The reproduced data from the disc 1 are eight to fourteen demodulated at t~e EFM demodulating circuit 121 of the reproducing circuit 120 before being supplied to the decoder 122. Depending on the select signals from the terminal 124, the decoder 122 is switched between decoding processing corresponding to convolution : . ' ' ^ ''.
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encoding for the continuous record mode and that corresponding to the sector complete encoding ~or the intermittent record mode, with the decoded output being transmitted as the reproduced data at the output terminal 123.
When seeking the desired sector during reproduction, the information of the Q-channel o~ the subcode can be utilized in the continuous record mode.
If the frequency spectrum of the address data recorded in the address regions 4 of the disc 1 in the ~or~ o2 the burst-like changes of the track width and thQ
frequency spectrum of the data recorded by pit3 or the ' tracking signals are designed to be separablQ ~roM each other, the address data recorded in the address region 4 can be used to seek the desired sector even when the recording is made with the continuous record mode.
In the intermittent record mode, the addres~
~nformation of the address regions 4 o~ the optical disc 1 are left over so that the add~ress data recorded in the ~O address regions 4 can be utilized in seeking the desired address.
In the above described optical disc o~ the present invention, address regions, each of a predet~rminQd length, are provided at predetermined spacings along the track length and the physical address data are recorded in these address regions in the form of the changes of the track width, suc~ that th~ addre~s data r~¢orded in these address regions can be utilized for writing the data in the desired sector.
The address data in the address regions are not recorded as the pits, so that data can be recQrded ~n these address regions when the record data are recorded in the continuous record modes, as when recording musical data or CD-ROM data.
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, In the intermittent record mode for CD-WO or CD-erasable, the 12~byte eync pattern represents a vacant region which can be in registration with the address ~ægion 4. In this case, the address data recorded in the address region 4 are left over after the data .recording such that the address data of the address ~gion 4 can be utilized to perform a high speed accessing when seeking the desired sector.
Therefore, according to the present invention, the ~dress_data on the disc ,can be utilized when the ~resent apparatus is used as a CD-WO or CD-erasable, while the interchangeability with a CD-ROM remains 'J intact.
~urning now to Fig. 7 which depicts an optical disc as the recording medium according to a second embodiment of the present invention, an optical disc 21 has a land between spirally formed pregrooves 22 as a recording -track 23. The centerline ~1 f the recording track is deviated at a predetermined per~iod across the track width or Y-Y' direction with respect to an imaginary centerline lo. The recording track 23 has its width changed in a burst-like manner. Similarly to the optical disc 1 of the foregoing first embodiment, the 2K-byte complete block data in accordance with the aforementioned CD-ROM data format are recorded photo-magnetically on the track 23.
In the optical disc 21 of the present second embodiment, the recording track 23 is in the form of a sinusoidal wave for affording predetermined period data WCK corresponding to a sampling frequency of 22.05 kHz which is one half the data sampling frequency 44.1 kHz of the CD-RON. In addition, there are formed address regions 24 at predetermined intervals and in register with the sync signal SYNC or error correction signal ECC
in the CD-ROM data format, wherein the address regions " ' ' ' , 24 are each formed as burst~ e track changes across the track width. The address *ata of, for example, 19 bits, are pre-recorded by these track changes in the widthwise direction. The signal fipectrum of the addre~
data ~ormed by the track width change is selected to be higher than the signal s~ectrum ~f the servo region.
Radially inside of the data region 26 of the optical disc 21, there is formed a lead-in region 27, into which there are recorded-the lead-in data indicating the recording s~ate ~ the data region 26.
In the present second e~bol~ment the data signals RF can be detected as the sum~a~ion output signal ~SA +
8B ~ SC + SD) from the adder 11 while the period information WCK and the address data ADR can be detected as the subtraction output signal (SA + Sg) - (Sc + SD) from the subtractor 14 by utilizing the four segment detector 10 shown in Fig. 4 as in the case of the above described first embodiment of t~e present invention.
The block view of Fig. 8 s~hows the arrangement of GO the recording/reproducing apparat~ wherein the optical disc 21 shown in Fig. 7 is used as the recording medium.
The recording/reproducing ~pparatus is 80 designed that the recording track 23 of the optical disc 21 i8 scanned optically by means of an optical pickup 31 for recording/reproducing data formulated in accordance with the above described CD-ROM data format, while ~he disc 21 is rotated at a constant linear velocity by a spindlQ
motor 30.
The optical pickup 31 is mainly constituted by a laser diode (not shown) which outputs a laser beam for data recording/reproduction, a photosensor for optically detecting data in the form of reflected light from the recording track of the optical disc 21, and an optical system (not shown) for irradiating the optical disc 21 with the laser beam from the laser diode and ~ 325~7~
transmitting the re~lected return beam from the disc 21 towards the phDtodetector. The optical pickup 31 includes two ~ur segment photodetectors 32, 33 as the photosensor, ~nd is~so arranged that the return laser beam from the disc 21 is transmitted to the ~our-segment photodetectors 32, 33 after separation into a P
polarized component and an S polarized component in the optical system (by means not shown).
As for th~ detection output from the four-segment photodetect~r 32, t~ which the P polarized component of the return beam is transmitted, the outputs SA and SB of the detectors A and ~, arrayed in the longitudinal ' direction (X - X' direation) of the recording track 23 r of the disc 21, are supplied to an adder 34, while theoutputs Sc, SD of the detectors C and D are supplied to an adder 35.
The summation output signal ~SA + Sg) from the adder 34 is supplied to adders 36 and 37, while th~
summation output signal (Sc + SD) from the adder 35 is ~upplied to the adder 36 and an adder 41.
As for the detection output ~rom the four segment photodetector ~3, to which the S polarized component of the return b~am is transmitted, the outputs SA' and SB' of the detector Al and B' arrayed in the longitudinal direction (X - X' direction) of the recording track 23 of the disc 21 are supplied to an adder 38, whi~e the outputs Sc~, S~ of the detectors C~ and~D' are supplied to an adder 3~.
The summation output signal (SA' + SB') from the adder 38 is supplied to the adder 37 and an adder 40 whereas the summatlon output signal (Sc' + SD') from the adder 39 is supplied to the adder 40 and the adder 41.
The summation output signal (SA + Sg + Sc +SD) by the adder 36 and the summation output signal (SA' + SB' + Sc' + SD') by the adder 40 are supplied to a 1 32~27~
.subtractor 42, whereby a reproduced RF s~gnal or RFS, where:
RFS ~ (SA + Sg + Sc + SD) - (SA' + SB + SC + SD ) is produced as the subtraction output ~i~pual from the subtractor 42.
This reproduced RF signal or RFS is supplied to a reproducing block 43, where the operation Df reproducing the 2K byte complete block data formed in accordance with the above described CD-ROM data forma~. and ~0 ph~tomagnetic~lly recorded on the record ~rack 23 of the optical disc 21 is performed under the c~l~rol og a system controller 100 to reproduce the block data from ' the reproduced RF signals tRFS).
on the other hand, the summation output signal (SA
+ SB + SA' + Sg') from the adder 37 and the summation output signal (Sc + SD + Sc' + SD') from the adder 41 are supplied to a subtractor 44, from which a subtraction output signal RFC, where:
RFC = (SA + Sg + BA' + Sg') - ;(Sc + SD + Sc' + SD ) ~.0 is pro.duced and.sllpplied to a control block 50.
At the input stage of the control block 50, the output of the subtractor 44 is supplied to a bandpass filter 51 making use of a tank circu~t having ~ high Q
and a resonance frequency of 22..0~ kHz for separati~
the reproduced control signals RFC from the 22.05 kHz sinusoidal signal component suppLiQd from the ~ecording track 22 o~ the disc 21 having.th~-shap~ of the sinusoidal wave. The sinusoidal.waw~ signal component corresponds to the predetermined period information WCK.
The output of the subtractor 44 is also supplied to a high-pass filter 52 for separating the address data component ADR, pre-recorded in the recording track 22 of the disc 21 as the track width changes, from the reproduced control signals RFC.
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The sinusoidal wave signals (Fig. 9) corre3ponding to the predetermined period data (WCK), which signal~
are separated by the bandpass filter 51, are supplied to phase comparators 53 and 54, while the address data component signals ADR, separated from the reproduced control signals RFC at the highpass filter 52, are supplied to a phase comparator 55 and an address decoder 56.
The phase comparator 53 performs a phase com~arison ~etween a reference phase signal from a refere~ce oscillator 57 for spindle servoing and the aforementioned sinusoidal wave signal obtained at the bandpass filter 51 and transmits the comparison output via a phase compensation circuit 58 to a driving circuit 59 of the spindle motor 30 to constitute a spindle servo system for rotationally driving the optical disc 21 at a constant linear velocity.
The phase comparator 54 performs a phase comparison between the output of a frequency divider 61, which divides the oscillation output of a voltage controlled oscillator 60 by a factor of 196, and the aforementioned sinusoidal wave signal obtained at the bandpass filter 51. The comparison output is transmitted through at low pass filter 62 to a signal adder 63 whose output ~s supplied to the control input terminal of the voltage controlled oscillator 60. Together, the circuits 54, 60, 61, 62 and 63 constitut~ a so-called phasQ lock loop (PLL) type clock reproducing system whereln t~e oscillation phase of the voltage controlled oscillator 60 is matched to the phase of the aforementioned sinusoidal wave signal.
The phase comparator 55 performs a phase comparison between the oscillation output of the voltage controlled oscillator 60 and the signal of the address data component ADR produced at the output of the highpass filter 5~ and transmits the c~mparison output through a lowpass filter 64 to the signal adder 63 v$a a switch 65 to constitute a so-called PLL ~ontrol æystem wherein the oscillation phase of the voltage controlled oscillator 60 is matched to the bit clock phase of the addrecc data (ADR).
The switch 65 is controlled by an output of the phase comparator 54 of the clock reproducing system so as to be closed initially and opened when the oscillation phase of the voltage controlled oscillator 60 i8 phase-locked to the sinusoidal wave signal.
Preferably, the control is so made that, after the bit ~t clock phase of the address data ADR has been detected f correctly, the switch 65 is closed only during the address period.
Under PLL control by the comparison outputs of the phase comparators 54, 55, the voltage controlled oscillator 60 outputs system clocks having the frequency of 4.3218 MHz matched to the b * clock phase of the address data ADR.
The system clocks produced by the voltage controlled oscillator 60 are supplied to the system controller lOQ adapt0d to control the operation of the recording/ reproducing apparatus, while being supplied simultaneously to the address decoder 56 and the record data buffer memory 90.
From the signals of the address data ADR produced at the highpass filter 52, the addresc decoder 56 decodes the address data ADR on the basis`of the system clocks and transmits the address data ADR to the system controller 100.
In the record mode, the system controller 100 controls the data buffer memory 90 supplied with the recording data and transmits the record data from the data buffer memory 90 to the recording processor 91 as :
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the control is made for each data block as one unit based on the address data ADR. The recording operation is controlled so that the block data completed by 2K
bytes in accordance with the CD-RON data format will be photomagnetically recorded on the record track 23 of the optical disc 21.
In the reproducing mode, the system controller 100 controls the data processing operation by the reproducing processing block 43 for reproducing the block data completed with 2K bytes, while performing control on a block-by-block basis using the address data ADR. The 2-byte complete block data are formed in accordance with the CD-ROM data format and are photomagnetically recorded on the recording track 23 of the optical disc 21.
In the recording medium of the present invention, the recording track width is changed in a burst fashion at regular intervals along the track length such that the control data having a predetermined number of bits are pre-recorded by the changes across the track width as the information for performing a~ block by block control of the recording data using the control data.
In the recording medium of the present invention, the track centerline is periodically displaced across the track width with respect to the imaginary track centerline, while the track width is changed i~ a burst-like fashion. In this manner, the period data are recorded previously by the deviation acro~ the track width of the track centerline as the,data~for block-by-block control of the record data. Simultaneously, thecontrol data having a predetermined number o~ bits are pre-recorded by the track width changes such that a block-by-block control of the recording data can be made on the basis of the period data and control data.
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According to the optical disc o~ the present invention, one subcode block is constituted by a predetermined frame, and the absolute address data can be pre-recorded as the control data in the form o~
record track width changes, so that the absolute address data of one sub-block can be obtained by reading out the one sub-block in its entirQty. Thus the data recorded or reproduced by the medium of the record track can be controlled on the basis of the above address data so that the data can be controlled efficiently for each block completed with 2K bytes. In addition, even when the data of the CD or CD-R~M data format are recorded on the recording track, the address data o~ a predetermined number of bits pre-recorded as the changes in the width of the recording track do not affect the data of the CD or CD-ROM format, so that interchangeability can be maintained with respect to the CD or CD-ROM.
Also, according to the recGrding apparatus of the ~0 present invention, the recording operation is controlled by the control means on the basis of the control or period data and control data detected from the recording medium by detection means so that block-by-block control o~ the recording data can be performed simply and reliably.
In addition, according to the reproducing~apparatus of the present invention, the reproducing operation i~
controlled by control means on the basis of the control or period data and control data detected from the recording medium by detecting means so that block-by-block control of the recording data can be performed simply and reliably.
Although the present invention has been shown and described with respect to preferred embodiments, various changes and modifications which are obvious to a person , ~ ., . -. .
7 .~
: ' ' :: '.' ækilled in the ~rt to which the invention pertains are deemed to lie ~ithin the spirit and scope of the invention.
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` In CD-ROMs, as shown in Fig. 2, the le~t and right ~hannel digital audio sign~ls recorded on the compact ~isc (CD) are alternately ~nnected at intervals of one .
lo word (2 8ymbols ~ 16 bits) ~D as to be treated as one channel of serial data and the CD is treated as a data storage device, a header sPction and sync signals are : ' annexed ahead of each subcode block or 98-frames of : ;
data in the CD data format, such that each sector or block is constituted by 2X bytes of data.
Since the conventional CD player is dedicated to reproduction, attempts have been made to develop a data - stora~e medium and the recording and/or reproducing system making use of the data çtorage medium, such as a 80 called "write once compact disc" (referred to as a - "CD-Wo") or an erasable compact disc ~re~erred to as "CD-erasable"). This CD-WO or CD-erasable makes use of a magneto-optical disc which is formed by a rewritable ....
magneto-optical recording medium and which is .
interchangeable with respect to the CD or CD-erasable, as disclosed in EP application No. 0265695 published on ; May 4, 1988.
In the data recording/reproducing system making use of a recording medium such as the CD-WO o~ CD-erasable, it is necessary to control data efficiently on a block-by-block basis. However, in the CD data format, there are only a few address data, such that, when the data format is used in a data storage medium such as CD-WO or , . ~ ~
~ 325274 CD-erasable, it is difficult to control the data on a block-by-block basis.
OBJECTS AND SUMMARY OF THE INVENTIO~
It is a principal object of the present invention to provide a data recording/reproducing system wherein data can be controlled efficiently on a block-by-block ba~
It is another ob~ect of the pr~sent invention to ~vide a recording medium ~herein ~ata can be controlled efficiently on a ~lock--by-block basis.
It is a further object of the present invention to provide a recording medium wherein interchangeability can be maintained with the CD or the CD-ROM.
It is a further object of the present invention to provide a recording apparatus and a reproducing apparatus wherein data can be controlled efficiently on a ~lock-by-block basis.
It is yet another object of the present invention to provide a data recording apparatus which can cope with the case of recording in a continuous recording mode, as when recording musical data, or CD-ROM
recording data, and which can utilize the address on the disc in the intermittent recording mode to provide for high speed accessing of recording/reproducing data for each sector as when using the apparatus as a C~-WO or as a CD-erasable.
The above and other objects of the present invention are attained by a recording medium having a recording track whose width is changed in a burst-like fashion to represent control data of a predetermined number of bits. The control data are the address data for each data block as one unit. The regions containing widthwise changes of the track, and thus including the address data, represent data record - . ~
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,,,, . -regions or data non-record regions depending on the recording mode, which can be either a modQ ~n which the recorded data are sub~ected to convolution encoding or a mode in which the recorded data are subje¢ted to sector S complete type encoding.
In still another embodiment of the invention, the recording medium has a recording track whose centerline i8 periodically displaced acros the track width with respect to an imaginary centerline of the recording track. The track width also changes in a burst-like fash~on, wherein period data are pre-recorded by the deviation of the track centerline across the track width and control data of a predetermined number of bits are represented by the ~urst-like changes of the track width.
The invention further includes an apparatus for recording data on such a recording medium and including detecting means for detecting the control data signals recorded on the recording trac~, the detecting means including two pairs ~f detectors, each pair being arranged across the tracX width and producing a separate push-pull output, and control means for controlling the data recording operation on the recording track based on the control data. The control data are address data and the control means controls the recording on the recording track based on the -' reproduced address ~gnal~. When the recor~ing medium has a recording track whose centerline i8 periodically displaced across the track width with respect to an imaginary centerline of the recording track, then the detecting means detec~s the period data as well as the control data and the control means controls the recording operation ~n the recording track based on the period data and the control data as represented by the push-pull outputs of the detecting means.
The above and other objects of the present invention will become more apparent upon reading the following description in conjunction with the accompanying drawinge.
s BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagrammatic view showing the data format of a compact disc (CD);
Fig. 2 is a diagrammatic view showing the data format of a CD-RO~;
Fig. 3 is a diagrammatic plan view showing an optical disc as the recording medium according to a ! first embodiment of the present invention together with t an enlarged detail view of three of the radial trac~s thereon;
Fig. 4 is a diagrammatic view showing an arrangement of an optical pickup adapted for reading data on the optical disc depicted in Fig. 3;
Fig. 5 is a diagrammatic yiew showing the data recording state on the recording track of the optical disc:
Fig. 6 is a block diagram showing an arrangement of a recording/reproducing apparatus employing th~ optical disc of the first embodiment as the recording medium;
Fig. 7 is a diagrammatic plan view of an optical disc as the recording medium according to a seaond embodiment of the present invention;
Fig. 8 i~ a block diagram showing the recor*ing /reproducing apparatus employing the opticai disc of the second embodiment as the recording medium; and Fig. 9 i8 a waveform diagram for illustrating the operation of the recording/reproducing apparatus.
1$fi5EIilIQN OF THE PREFERRED EMBODI~
~eferring to the drawings, certain illuqtrative embodiments of t~e present invention will be explained in more detail.
Referring now to Fig. 3 wherein all or part of the optical disc as the recording medium according to a ~irst embodiment of the present invention is ~iagrammatically æhown, a magneto-optical disc is ~ployed as the ~p~ical disc 1 in which a ~rpendicularly ~gnetized film having magneto-optical effects is formed on a transparent base plate. The lands sandwiched between the spirally formed pregrooves s 2 are formed as the recording track 3 and the block data completed by 2K bytes of data in accordance with the above described CD-ROM data format are photo-magnetically recorded on the recording track 3. A long portion of the length of the spiral track 3 constitutes the data region 6 where data are recorded.
In the recording track 3, address regions 4 are provided at equidistant positions along the length of the track 3 corresponding to the sync aignal (SYNC) portion or to the error correction code (ECC) portion in the above CD-ROM data format. Each address region 4 represents burst-like changes across the track width whereby 19-bit address data, for example, are pre-recorded in each address region 4. The signal spectrum of the address data produced by the changes across the track width is selected to represent a co~ponent higher than that of the frequency spectrum of the servo region.
Radially interior from the data region 6 there is formed a lead-in region 7, in which there are recorded lead-in data indicating the recording state of the data region 6.
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In the optical disc 1 ~f the first embodiment of the invéntion there are recorded in each address region 4 address data of a predetermined bit number by the changes acros~ the track width. As shown in Fig. 4, a four segment detector 10 composed of four photodetectors A, B, C and D is used in conj~nction with a laser light source (not shown) as a data read-out optical pickup.
Thus, a data signal RF can ~.e detected in the ~orm of a summation output signal S~ ~ SB ~ 8c + SD obtained by summing the outputs SA, Sg, S~, and SD of t~e respectivc detectors A, B, C and D at an adder ll. On the other hand, an address information signal ADR can be detected ,~ in the form of a subtraction output signal equal to tSA
~ Sg) - (Sc + SD) obtained by subtracting in a subtractor 14 a summation output (Sc + SD) of the outputs Sc and SD of the detectors C and D produced by an ad~er 13 from a s~mmation output (SA + Sg) produced by an adder 12 of the Dutputs SA and SB of the detectors A and B, wherein the ~etectorssA, B and C, D are arranged in the longitudinal or X - X' direction of the recording track 3, that is, in the form of push-pull output~ SA - SD and Sg - Sc, and the detectors A, D and B, C are arranged in.the widthwise direction or Y - Y~
. direction of the recording track 3.
The address information ADR does not substantially affect the data signal RF. Thus, as shown in ~ig. 5, the ~ta recordlng region 5 can be extended up to and thrcugh the address region 4 of the recording track 3.
In the above described optical disc 1~, the address regions 4 are provided at predetermined intervals along the l~ngth of the signal track 3, wherein the address information o~ the signal spectrum above the servo regian is indicated as changes across the track width, so that the block data completed by 2K bytes of data in accordance with the CD-ROM data format can be recorded .: - --on or reproduced from the recording track 3 on the basis of the above address information without the tracking servo or focusing servo for the recording track 3 being disturbed by the address in~ormation or data.
Data recording can be made in two modes on the optical disc 1. one of such modes is that for the above described continuous recording. This mode for continuous recording is convenient for direct recording of CD-ROM data or of sequential data, such as musical data.
In this continuous recording mode, there is no time period which is devoid of data, so that, as shown in s Fig. 5, the pits 5 are also formed in the address region 4, which is used simultaneously as the data record region.
The other mode i8 the mode for intermittent recording, which is convenient for recording data at randomly selected addresses, as in the case o~ CD-WO or CD-erasable. ~
The basic data structure for such an intermittent recording mode is similar to that for continuous rding except that the 12-byte sync signals for musical signal blocking in the data format shown in Fig.
2 are not provided for in the intermittent record mode, in which data are recorded with a 98 frame sect~r as one recording unit. In each of these sectors,~there are recorded the same dat~ as those of the data format shown in Fig. 2 except the 12-byte sync signals Sor blocking the musical signals.
Thus, in the intermittent recording mode, a vacant region equivalent to 12 bytes can be procured in each sector having a total data capacity of 2352 bytes. This 12-byte vacant region corresponds to the address region 4.
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g Therefore, when data are recorded in the intermittent record mode, no data are recorded in the address regions 4, so that the address data recorded in the address regions are left over a~ter data recording.
Thus, the address information recorded in the address regions 4 can be resorted to for seeking desired sectors.
In the intermittent recording mode, the encoding co~ple~ed in each sector is used instea~ of convolution e~coding. Encoding complete in each sector can be realized by a method described in, for example, the Japanese Patent Application No. 118567/1988. The merging bit at the time of recording with EFM modulation is reset at each sector.
Fig. 6 shows diagrammatically the digital data recording/reproducing apparatus to which the present invention is applied. This apparatus is designed to record or reproduce digital da~ optically by using the optical disc 1 shown in Fig. 3~as the recording medium, and is provided with a recording circuit 110 and a reproducing circuit 120.
The optical disc 1 is pro~i~ed with the above described address regions 4 in each of which ar~
recorded physical address data as burst-like changes of the track width. The disc 1 performs a revolution at a constant linear velocity (CLV3.
The recording circuit 110 can be set to the above described continuous record an~ intermittent record modes responsive to select signals from the terminal 114.
The 12-byte sync signals are provided in each sector for the continuous record mode but are not provided for in the intermittent record mode.
During recording, data to be recorded on the optical disc 1 are supplied from a data input terminal - .~
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111 to an encoder 112 of the recording circuit 110. The address of the optical disc 1 can be obtained from the address information recorded in the address information 4 80 that a desired address can be souqht to record the data therein. The data from the data input terminal 111 are developed in the encoder 112 into a predetermined frame structure for annexing duplex error correction codes of the Cl and C2 series. This encoding is by the convolution encoding ~or continuous record mode and by the sector-complete encoding for the intermittent record mode. The data to which the duplex error correction codes are annexed at the encoder 112 are eight to fourteen modulated at the EFM circuit 113 so as to be t recorded in the sector of the optical disc 1 bearing the desired address.
In the continuous record mode, data are recorded in the address regions 4 provided on the optical disc 1.
Conversely, in the intermittent r~cord mode, no data are recorded in the address region~ 4 of the optical disc 1 so that the address data recorded in these address regions 4 as the burst-like changes of the track width remain unaf~ected.
The data recorded on the disc 1 can be reproduced by a sequence which is the reverse of the above described sequence adopted for recording.
Thus, the above described continuous reco~d or interm~tt~nt modes can be set in the reproducing ci~;t 120 depending on the select signals from the terminal 124.
The reproduced data from the disc 1 are eight to fourteen demodulated at t~e EFM demodulating circuit 121 of the reproducing circuit 120 before being supplied to the decoder 122. Depending on the select signals from the terminal 124, the decoder 122 is switched between decoding processing corresponding to convolution : . ' ' ^ ''.
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encoding for the continuous record mode and that corresponding to the sector complete encoding ~or the intermittent record mode, with the decoded output being transmitted as the reproduced data at the output terminal 123.
When seeking the desired sector during reproduction, the information of the Q-channel o~ the subcode can be utilized in the continuous record mode.
If the frequency spectrum of the address data recorded in the address regions 4 of the disc 1 in the ~or~ o2 the burst-like changes of the track width and thQ
frequency spectrum of the data recorded by pit3 or the ' tracking signals are designed to be separablQ ~roM each other, the address data recorded in the address region 4 can be used to seek the desired sector even when the recording is made with the continuous record mode.
In the intermittent record mode, the addres~
~nformation of the address regions 4 o~ the optical disc 1 are left over so that the add~ress data recorded in the ~O address regions 4 can be utilized in seeking the desired address.
In the above described optical disc o~ the present invention, address regions, each of a predet~rminQd length, are provided at predetermined spacings along the track length and the physical address data are recorded in these address regions in the form of the changes of the track width, suc~ that th~ addre~s data r~¢orded in these address regions can be utilized for writing the data in the desired sector.
The address data in the address regions are not recorded as the pits, so that data can be recQrded ~n these address regions when the record data are recorded in the continuous record modes, as when recording musical data or CD-ROM data.
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, In the intermittent record mode for CD-WO or CD-erasable, the 12~byte eync pattern represents a vacant region which can be in registration with the address ~ægion 4. In this case, the address data recorded in the address region 4 are left over after the data .recording such that the address data of the address ~gion 4 can be utilized to perform a high speed accessing when seeking the desired sector.
Therefore, according to the present invention, the ~dress_data on the disc ,can be utilized when the ~resent apparatus is used as a CD-WO or CD-erasable, while the interchangeability with a CD-ROM remains 'J intact.
~urning now to Fig. 7 which depicts an optical disc as the recording medium according to a second embodiment of the present invention, an optical disc 21 has a land between spirally formed pregrooves 22 as a recording -track 23. The centerline ~1 f the recording track is deviated at a predetermined per~iod across the track width or Y-Y' direction with respect to an imaginary centerline lo. The recording track 23 has its width changed in a burst-like manner. Similarly to the optical disc 1 of the foregoing first embodiment, the 2K-byte complete block data in accordance with the aforementioned CD-ROM data format are recorded photo-magnetically on the track 23.
In the optical disc 21 of the present second embodiment, the recording track 23 is in the form of a sinusoidal wave for affording predetermined period data WCK corresponding to a sampling frequency of 22.05 kHz which is one half the data sampling frequency 44.1 kHz of the CD-RON. In addition, there are formed address regions 24 at predetermined intervals and in register with the sync signal SYNC or error correction signal ECC
in the CD-ROM data format, wherein the address regions " ' ' ' , 24 are each formed as burst~ e track changes across the track width. The address *ata of, for example, 19 bits, are pre-recorded by these track changes in the widthwise direction. The signal fipectrum of the addre~
data ~ormed by the track width change is selected to be higher than the signal s~ectrum ~f the servo region.
Radially inside of the data region 26 of the optical disc 21, there is formed a lead-in region 27, into which there are recorded-the lead-in data indicating the recording s~ate ~ the data region 26.
In the present second e~bol~ment the data signals RF can be detected as the sum~a~ion output signal ~SA +
8B ~ SC + SD) from the adder 11 while the period information WCK and the address data ADR can be detected as the subtraction output signal (SA + Sg) - (Sc + SD) from the subtractor 14 by utilizing the four segment detector 10 shown in Fig. 4 as in the case of the above described first embodiment of t~e present invention.
The block view of Fig. 8 s~hows the arrangement of GO the recording/reproducing apparat~ wherein the optical disc 21 shown in Fig. 7 is used as the recording medium.
The recording/reproducing ~pparatus is 80 designed that the recording track 23 of the optical disc 21 i8 scanned optically by means of an optical pickup 31 for recording/reproducing data formulated in accordance with the above described CD-ROM data format, while ~he disc 21 is rotated at a constant linear velocity by a spindlQ
motor 30.
The optical pickup 31 is mainly constituted by a laser diode (not shown) which outputs a laser beam for data recording/reproduction, a photosensor for optically detecting data in the form of reflected light from the recording track of the optical disc 21, and an optical system (not shown) for irradiating the optical disc 21 with the laser beam from the laser diode and ~ 325~7~
transmitting the re~lected return beam from the disc 21 towards the phDtodetector. The optical pickup 31 includes two ~ur segment photodetectors 32, 33 as the photosensor, ~nd is~so arranged that the return laser beam from the disc 21 is transmitted to the ~our-segment photodetectors 32, 33 after separation into a P
polarized component and an S polarized component in the optical system (by means not shown).
As for th~ detection output from the four-segment photodetect~r 32, t~ which the P polarized component of the return beam is transmitted, the outputs SA and SB of the detectors A and ~, arrayed in the longitudinal ' direction (X - X' direation) of the recording track 23 r of the disc 21, are supplied to an adder 34, while theoutputs Sc, SD of the detectors C and D are supplied to an adder 35.
The summation output signal ~SA + Sg) from the adder 34 is supplied to adders 36 and 37, while th~
summation output signal (Sc + SD) from the adder 35 is ~upplied to the adder 36 and an adder 41.
As for the detection output ~rom the four segment photodetector ~3, to which the S polarized component of the return b~am is transmitted, the outputs SA' and SB' of the detector Al and B' arrayed in the longitudinal direction (X - X' direction) of the recording track 23 of the disc 21 are supplied to an adder 38, whi~e the outputs Sc~, S~ of the detectors C~ and~D' are supplied to an adder 3~.
The summation output signal (SA' + SB') from the adder 38 is supplied to the adder 37 and an adder 40 whereas the summatlon output signal (Sc' + SD') from the adder 39 is supplied to the adder 40 and the adder 41.
The summation output signal (SA + Sg + Sc +SD) by the adder 36 and the summation output signal (SA' + SB' + Sc' + SD') by the adder 40 are supplied to a 1 32~27~
.subtractor 42, whereby a reproduced RF s~gnal or RFS, where:
RFS ~ (SA + Sg + Sc + SD) - (SA' + SB + SC + SD ) is produced as the subtraction output ~i~pual from the subtractor 42.
This reproduced RF signal or RFS is supplied to a reproducing block 43, where the operation Df reproducing the 2K byte complete block data formed in accordance with the above described CD-ROM data forma~. and ~0 ph~tomagnetic~lly recorded on the record ~rack 23 of the optical disc 21 is performed under the c~l~rol og a system controller 100 to reproduce the block data from ' the reproduced RF signals tRFS).
on the other hand, the summation output signal (SA
+ SB + SA' + Sg') from the adder 37 and the summation output signal (Sc + SD + Sc' + SD') from the adder 41 are supplied to a subtractor 44, from which a subtraction output signal RFC, where:
RFC = (SA + Sg + BA' + Sg') - ;(Sc + SD + Sc' + SD ) ~.0 is pro.duced and.sllpplied to a control block 50.
At the input stage of the control block 50, the output of the subtractor 44 is supplied to a bandpass filter 51 making use of a tank circu~t having ~ high Q
and a resonance frequency of 22..0~ kHz for separati~
the reproduced control signals RFC from the 22.05 kHz sinusoidal signal component suppLiQd from the ~ecording track 22 o~ the disc 21 having.th~-shap~ of the sinusoidal wave. The sinusoidal.waw~ signal component corresponds to the predetermined period information WCK.
The output of the subtractor 44 is also supplied to a high-pass filter 52 for separating the address data component ADR, pre-recorded in the recording track 22 of the disc 21 as the track width changes, from the reproduced control signals RFC.
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The sinusoidal wave signals (Fig. 9) corre3ponding to the predetermined period data (WCK), which signal~
are separated by the bandpass filter 51, are supplied to phase comparators 53 and 54, while the address data component signals ADR, separated from the reproduced control signals RFC at the highpass filter 52, are supplied to a phase comparator 55 and an address decoder 56.
The phase comparator 53 performs a phase com~arison ~etween a reference phase signal from a refere~ce oscillator 57 for spindle servoing and the aforementioned sinusoidal wave signal obtained at the bandpass filter 51 and transmits the comparison output via a phase compensation circuit 58 to a driving circuit 59 of the spindle motor 30 to constitute a spindle servo system for rotationally driving the optical disc 21 at a constant linear velocity.
The phase comparator 54 performs a phase comparison between the output of a frequency divider 61, which divides the oscillation output of a voltage controlled oscillator 60 by a factor of 196, and the aforementioned sinusoidal wave signal obtained at the bandpass filter 51. The comparison output is transmitted through at low pass filter 62 to a signal adder 63 whose output ~s supplied to the control input terminal of the voltage controlled oscillator 60. Together, the circuits 54, 60, 61, 62 and 63 constitut~ a so-called phasQ lock loop (PLL) type clock reproducing system whereln t~e oscillation phase of the voltage controlled oscillator 60 is matched to the phase of the aforementioned sinusoidal wave signal.
The phase comparator 55 performs a phase comparison between the oscillation output of the voltage controlled oscillator 60 and the signal of the address data component ADR produced at the output of the highpass filter 5~ and transmits the c~mparison output through a lowpass filter 64 to the signal adder 63 v$a a switch 65 to constitute a so-called PLL ~ontrol æystem wherein the oscillation phase of the voltage controlled oscillator 60 is matched to the bit clock phase of the addrecc data (ADR).
The switch 65 is controlled by an output of the phase comparator 54 of the clock reproducing system so as to be closed initially and opened when the oscillation phase of the voltage controlled oscillator 60 i8 phase-locked to the sinusoidal wave signal.
Preferably, the control is so made that, after the bit ~t clock phase of the address data ADR has been detected f correctly, the switch 65 is closed only during the address period.
Under PLL control by the comparison outputs of the phase comparators 54, 55, the voltage controlled oscillator 60 outputs system clocks having the frequency of 4.3218 MHz matched to the b * clock phase of the address data ADR.
The system clocks produced by the voltage controlled oscillator 60 are supplied to the system controller lOQ adapt0d to control the operation of the recording/ reproducing apparatus, while being supplied simultaneously to the address decoder 56 and the record data buffer memory 90.
From the signals of the address data ADR produced at the highpass filter 52, the addresc decoder 56 decodes the address data ADR on the basis`of the system clocks and transmits the address data ADR to the system controller 100.
In the record mode, the system controller 100 controls the data buffer memory 90 supplied with the recording data and transmits the record data from the data buffer memory 90 to the recording processor 91 as :
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the control is made for each data block as one unit based on the address data ADR. The recording operation is controlled so that the block data completed by 2K
bytes in accordance with the CD-RON data format will be photomagnetically recorded on the record track 23 of the optical disc 21.
In the reproducing mode, the system controller 100 controls the data processing operation by the reproducing processing block 43 for reproducing the block data completed with 2K bytes, while performing control on a block-by-block basis using the address data ADR. The 2-byte complete block data are formed in accordance with the CD-ROM data format and are photomagnetically recorded on the recording track 23 of the optical disc 21.
In the recording medium of the present invention, the recording track width is changed in a burst fashion at regular intervals along the track length such that the control data having a predetermined number of bits are pre-recorded by the changes across the track width as the information for performing a~ block by block control of the recording data using the control data.
In the recording medium of the present invention, the track centerline is periodically displaced across the track width with respect to the imaginary track centerline, while the track width is changed i~ a burst-like fashion. In this manner, the period data are recorded previously by the deviation acro~ the track width of the track centerline as the,data~for block-by-block control of the record data. Simultaneously, thecontrol data having a predetermined number o~ bits are pre-recorded by the track width changes such that a block-by-block control of the recording data can be made on the basis of the period data and control data.
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According to the optical disc o~ the present invention, one subcode block is constituted by a predetermined frame, and the absolute address data can be pre-recorded as the control data in the form o~
record track width changes, so that the absolute address data of one sub-block can be obtained by reading out the one sub-block in its entirQty. Thus the data recorded or reproduced by the medium of the record track can be controlled on the basis of the above address data so that the data can be controlled efficiently for each block completed with 2K bytes. In addition, even when the data of the CD or CD-R~M data format are recorded on the recording track, the address data o~ a predetermined number of bits pre-recorded as the changes in the width of the recording track do not affect the data of the CD or CD-ROM format, so that interchangeability can be maintained with respect to the CD or CD-ROM.
Also, according to the recGrding apparatus of the ~0 present invention, the recording operation is controlled by the control means on the basis of the control or period data and control data detected from the recording medium by detection means so that block-by-block control o~ the recording data can be performed simply and reliably.
In addition, according to the reproducing~apparatus of the present invention, the reproducing operation i~
controlled by control means on the basis of the control or period data and control data detected from the recording medium by detecting means so that block-by-block control of the recording data can be performed simply and reliably.
Although the present invention has been shown and described with respect to preferred embodiments, various changes and modifications which are obvious to a person , ~ ., . -. .
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: ' ' :: '.' ækilled in the ~rt to which the invention pertains are deemed to lie ~ithin the spirit and scope of the invention.
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Claims (20)
1. A recording medium having a recording track comprising first portions alternating at regular intervals with second portions, wherein the recording track has substantially constant width along each of the first portions, and changing width along each of the second portions, wherein the changing width along each of the second portions determines a set of a predetermined number of control data bits, wherein each said set of said predetermined number of bits determines address data for a different data block.
2. The recording medium of claim 1, wherein information data are recorded in said second portions.
3. A recording medium having a recording track comprising first portions that alternate at regular intervals with second portions, wherein the recording track has substantially constant width along each of the first portions, and changing width along each of the second portions, wherein the changing width along each of the second portions represents a predetermined number of control data bits, wherein each said predetermined number of control data bits are address data for each data block as one unit, wherein information data are also recorded in said second portions, and wherein the information data are convolution encoded.
4. A recording medium comprising:
a recordable surface; and a recording track on the recordable surface, having a track width and a centerline, wherein the track has first portions alternating at regular intervals with second portions, wherein the track width is substantially constant along each of the first portions and the track width changes along each of the second portions, wherein the centerline is periodically displaced relative to the track width and wherein displacement of the centerline relative to the track width represents period data, and wherein the changes in the track width along each of the second portions represents a predetermined number of control data bits.
a recordable surface; and a recording track on the recordable surface, having a track width and a centerline, wherein the track has first portions alternating at regular intervals with second portions, wherein the track width is substantially constant along each of the first portions and the track width changes along each of the second portions, wherein the centerline is periodically displaced relative to the track width and wherein displacement of the centerline relative to the track width represents period data, and wherein the changes in the track width along each of the second portions represents a predetermined number of control data bits.
5. The recording medium of claim 4, wherein each said predetermined number of control data bits represent address data for a different data block.
6. The recording medium of claim 5, wherein information data are recorded in the second portions.
7. A recording medium comprising:
a recordable surface; and a recording track on the recordable surface, having a track width and a centerline, wherein the track has first portions alternating at regular intervals with second portions, wherein the track width is substantially constant along each of the first portions and the track width changes along each of the second portions, wherein the centerline is periodically displaced relative to the track width, wherein displacement of the centerline relative to the track width represents period data, wherein the changes in the track width along each of the second portions represents a predetermined number of control data bits, wherein each said predetermined number of control data bits represent address data for a different data block, wherein information data are recorded in the second portions, and wherein the information data are convolution encoded.
a recordable surface; and a recording track on the recordable surface, having a track width and a centerline, wherein the track has first portions alternating at regular intervals with second portions, wherein the track width is substantially constant along each of the first portions and the track width changes along each of the second portions, wherein the centerline is periodically displaced relative to the track width, wherein displacement of the centerline relative to the track width represents period data, wherein the changes in the track width along each of the second portions represents a predetermined number of control data bits, wherein each said predetermined number of control data bits represent address data for a different data block, wherein information data are recorded in the second portions, and wherein the information data are convolution encoded.
8. An apparatus for use with a recording medium of the type which includes a recording track whose width changes along said recording track to represent control information, wherein record data is also recorded along the recording track, said apparatus comprising:
detecting means for detecting the control information and the record data, said detecting means including two pairs of detectors, each of said pairs of detectors being arranged across the track width; and means for adding and subtracting output signals from selected ones of the detectors, to generate control signals representing said control information.
detecting means for detecting the control information and the record data, said detecting means including two pairs of detectors, each of said pairs of detectors being arranged across the track width; and means for adding and subtracting output signals from selected ones of the detectors, to generate control signals representing said control information.
9. The apparatus according to claim 8 wherein the control signals represent address data.
10. An apparatus for use with a recording medium of the type which includes a recording track whose width changes along said recording track to represent address data, wherein record data is also recorded along the recording track, said apparatus comprising:
detecting means for detecting the address and the record data, said detecting means including two pairs of detectors, each of said pairs of detectors being arranged across the track width; and means for adding and subtracting output signals from selected ones of the detectors, to generate control signals representing said address data, wherein the record data are convolution encoded.
detecting means for detecting the address and the record data, said detecting means including two pairs of detectors, each of said pairs of detectors being arranged across the track width; and means for adding and subtracting output signals from selected ones of the detectors, to generate control signals representing said address data, wherein the record data are convolution encoded.
11. A recording apparatus for use with a record medium of the type having a recording track, wherein the recording track has a centerline and a track width, and wherein the centerline is periodically displaced relative to the track width to represent period data, and wherein the track width changes along the recording track to represent control data, said recording apparatus including:
detecting means for detecting the period data and the control data, the detecting means including at least two pairs of detectors, each of said pairs being arranged across the track width, and also including means for combining an output signal from a first detector in each of the pairs with an output signal from a second detector in said each of the pairs to generate push-pull output signals, wherein the push-pull output signals represent said period data and said control data, and control means for controlling the recording of record data on the recording track based on the period data and the control data as represented by the push-pull output signals.
detecting means for detecting the period data and the control data, the detecting means including at least two pairs of detectors, each of said pairs being arranged across the track width, and also including means for combining an output signal from a first detector in each of the pairs with an output signal from a second detector in said each of the pairs to generate push-pull output signals, wherein the push-pull output signals represent said period data and said control data, and control means for controlling the recording of record data on the recording track based on the period data and the control data as represented by the push-pull output signals.
12. A recording apparatus as recited in claim 11 wherein the detecting means includes means for adding the output signal from the first detector in said each of the pairs to the output signal from said second detector in said each of the pairs.
13. A reproducing apparatus for use with a recording medium of the type which includes a recording track whose width changes along the recording track to represent control data, comprising:
detecting means for detecting the control data signals recorded on the recording track, the detecting means including two pairs of detectors, each of the pairs being arranged across the track width, and also including means for combining an output signal from a first detector in each of the pairs with an output signal from a second detector in said each of the; pairs to generate push-pull output signals, wherein the push-pull output signals represent said control data, and control means for controlling reproduction of data recorded on the recording track in response to the push-pull output signals.
detecting means for detecting the control data signals recorded on the recording track, the detecting means including two pairs of detectors, each of the pairs being arranged across the track width, and also including means for combining an output signal from a first detector in each of the pairs with an output signal from a second detector in said each of the; pairs to generate push-pull output signals, wherein the push-pull output signals represent said control data, and control means for controlling reproduction of data recorded on the recording track in response to the push-pull output signals.
14. A recording medium having a recording track comprising first portions alternating at regular intervals with second portions, wherein the recording track has substantially constant width along each of the first portions, and changing width along each of the second portions, wherein the changing width along each of the second portions represents a predetermined number of control data bits, wherein each said predetermined number of control data bits represent address data for a different data block, and wherein the recording track includes pits in said second portions which represent record data, wherein the record data are encoded in accordance with a sector complete type encoding algorithm.
15. A recording medium, comprising:
a recordable surface; and a recording track on the recordable surface, having a track width and a centerline, wherein the track has first portions alternating at regular intervals with second portions, wherein the track width is substantially constant along each of the first portions and the track width changes along each of the second portions, wherein the centerline is periodically displaced relative to the track width and wherein displacement of the centerline relative to the track width represents period data, and wherein the changes in the track width along each of the second portions represents a predetermined number of control data bits, wherein each said predetermined number of control data bits represent address data for a different data block, wherein the recording track includes pits in the second portions which represent record data, wherein the record data are encoded in accordance with a sector complete type encoding algorithm.
a recordable surface; and a recording track on the recordable surface, having a track width and a centerline, wherein the track has first portions alternating at regular intervals with second portions, wherein the track width is substantially constant along each of the first portions and the track width changes along each of the second portions, wherein the centerline is periodically displaced relative to the track width and wherein displacement of the centerline relative to the track width represents period data, and wherein the changes in the track width along each of the second portions represents a predetermined number of control data bits, wherein each said predetermined number of control data bits represent address data for a different data block, wherein the recording track includes pits in the second portions which represent record data, wherein the record data are encoded in accordance with a sector complete type encoding algorithm.
16. An apparatus for use with a recording medium including a recording track whose width changes along said recording track to represent control information, wherein the recording track includes regions containing widthwise changes, and wherein record data is recorded in said regions, said apparatus comprising:
detecting means for detecting the control information and the data, said detecting means including two pairs of detectors, each of said pairs of detectors being arranged across the track width; and means for adding and subtracting output signals from selected ones of the detectors, to generate control signals representing said control information, wherein the control signals represent address data, wherein the record data are encoded in accordance with a sector complete type encoding algorithm.
detecting means for detecting the control information and the data, said detecting means including two pairs of detectors, each of said pairs of detectors being arranged across the track width; and means for adding and subtracting output signals from selected ones of the detectors, to generate control signals representing said control information, wherein the control signals represent address data, wherein the record data are encoded in accordance with a sector complete type encoding algorithm.
17. An optical recording medium having a recording track comprising first portions alternating at regular intervals with second portions,wherein the recording track has substantially constant width along each of the first portions, and changing width along each of the second portions, wherein the changing width along each of the second portions represents a predetermined number of control data bits for use in recording data on the recording track or reproducing data therefrom.
18. The optical recording medium according to claim 17 wherein the control data bits represent address information.
19. The optical recording medium according to claim 17, including at least two recording tracks formed concentrically thereon, each of said recording tracks comprising first portions alternating at regular intervals withsecond portions, wherein said each of the recording tracks has substantially constant width along each of the first portions, and changing width along each of the second portions, wherein the changing width along each of the second portions represents a predetermined number of control data bits.
20. The optical recording medium according to claim 17 wherein the recording track is formed spirally.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP149958/88 | 1988-06-20 | ||
| JP14995888 | 1988-06-20 | ||
| JP041784/89 | 1989-02-23 | ||
| JP1041784A JP2844638B2 (en) | 1988-06-20 | 1989-02-23 | Recording medium, its recording device and reproducing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1325274C true CA1325274C (en) | 1993-12-14 |
Family
ID=26381447
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 603254 Expired - Lifetime CA1325274C (en) | 1988-06-20 | 1989-06-19 | Recording medium and recording and reproducing apparatus employing the recording medium |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1325274C (en) |
-
1989
- 1989-06-19 CA CA 603254 patent/CA1325274C/en not_active Expired - Lifetime
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