JPH04155666A - Optical recording carrier - Google Patents

Abstract

PURPOSE:To realize simultaneous reproduction on the opposite surfaces of a recording carrier by providing record carrier identifying information on a track and further providing mark information, respectively, in front and rear of the identifying information in the circumferential direction. CONSTITUTION:A spiral guide track in a recording carrier is split circumferentially into four sectors 2. Each sector 2 comprises an address signal area 3 provided previously at the head and a signal recording area 4. The area 3 discriminates between a track position in the radial direction and a sector position in the circumferential direction. Signals are recorded on the area 4 while confirming the track and the sector number stored in the area 3. The area 3 is provided with sector marks SM 21, 22 for identifying the area 3 and address marks AM 25, 26 for address information. Address information recorded in carriers 1a, 1b is read out by means of reading heads disposed above and below the carrier 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of Application The present invention relates to an optical record carrier for recording or reproducing signals using a light source such as a semiconductor laser. A record carrier is rotated at a predetermined rotational speed, and a light beam generated from a light source such as a semiconductor laser is focused and irradiated onto the record carrier to record a signal on the record carrier or to record a signal recorded on the record carrier. There is an optical recording and reproducing device that reproduces .

This record carrier has a width of 0.6 micrometers and a pitch of 0.6 micrometers.
A minute track of 1.6 micrometers is provided in a spiral shape, and when recording a signal on a record carrier, the intensity of the light beam is modulated to be strong or weak. When reproducing a signal, the reflected light from the record carrier is converted into a photocurrent using a photodetector.

In order to increase the capacity of record carriers, record carriers of the same format are pasted together to form a single double-sided record carrier, which doubles the storage capacity per L.
In a device that handles such double-sided record carriers, there is a method for recording information on the opposite side or reproducing recorded information: - The record carrier is reversed and reloaded on a boat. The present invention also includes a device in which the optical head is configured to move in a U-shape with the record carrier in between, and the head is configured to automatically move to the opposite side without having to reload the record carrier. Problems that the company is trying to solveIncreasing the capacity of record carriers is a demand of the times. Compared to the conventional device 1 for double-sided discs, it was necessary to reload the disc when reproducing information on the opposite side, which was very inconvenient for the user.Also, in the case of a device with a structure in which the optical head moves automatically Since the L head must be moved to the opposite side and the rotation of the record carrier must be reversed, it takes a very long time to reproduce the information recorded on the opposite side. This was done in view of the above conventional drawbacks,
The first record carrier of the present invention is a double-sided disc-shaped record carrier made by pasting together two record carriers of the same format. a record carrier, provided with identification information for identifying the position of the record carrier on a spiral or concentric track, and a first for detecting the position of the identification information before and after the identification information in the circumferential direction This is provided with second mark information.

Also, a second record carrier according to the present invention is a double-sided disc-shaped record carrier in which two record carriers of the same format are pasted together, and the position of the record carrier is identified on a spiral or concentric track. Provide identification information for
Synchronization information for reading the identification information is provided before and after the identification information in the circumferential direction.

Operation First record carrier 11 of the present invention Since the first and second mark information for detecting the position of the identification information are provided before and after the identification information in the circumferential direction, the reading head can be installed above and below the record carrier. Therefore, the position of the identification information on both sides can be detected reliably and the identification information can be read even if the record carrier is rotated in the same direction. Record carrier of the second invention Table 6 Synchronization information for reading the identification information is provided before and after the identification information in the circumferential direction. With reading heads installed on the top and bottom, the synchronization signal necessary to read the identification information can be obtained before the identification information with the record carrier rotated in the same direction.
Identification information can be read stably.

Example The present invention will be described in detail below with reference to the drawings.

鞞 In the numbers used to explain drawings, the same numbers are used for the same items.

FIG. 1 is an overview diagram of an embodiment of a disc-shaped optical record carrier of the present invention. FIG. 1(A) shows a cross-sectional view taken at the center of rotation of the record carrier 1. 1b4
Comprised of a base material with a spiral guide track on one surface, a recording material layer formed on the base material by a method such as vapor deposition or sputtering, and a protective layer to protect the recording material. LLTe as a recording material
A phase change type recording material based on Recording carrier 1
is made by pasting together the information carrier sides of record carriers 1a and 1b, and when recording a signal on record carrier 1a or reproducing a recorded signal, a light beam is irradiated from the upper side of record carrier 1b. When recording a signal on the recording medium or reproducing a recorded signal, a light beam is irradiated from below. Therefore, if the record carrier 1 is rotated and tracking is controlled so that the light beam is positioned on the guide track, even if the light beams are viewed in the same direction,
The direction of movement of the light beam is for record carrier 1a and for record carrier 1.
Figure 1 (B) i; ing. Even though the spiral guide track (omitted) is divided into four sectors 2 in one rotation of the record carrier 1, each sector 2
The address signal area 31 is composed of an address signal area 3 provided in advance at the beginning of the address signal area 3 and a recording area 4 for recording signals. Am Figure 1 (A)
The plan view of the record carrier 1 seen from below also shows the same force as in Figure (B) (the rotational direction is opposite to the arrow 5). Therefore, the track and sector numbers recorded in the address signal area 3 are Since the signal is recorded on the recording area 4 after checking the address signal area 3, the positional relationship of the recording area 4 in the circumferential direction with respect to the address signal area 3 is opposite. As explained with the diagram, the signal recorded in the address signal area 3 is a 2-7 modulation code. 45M21 and 22 are sector markers for identifying the address signal area 3. VF023 and 24 read the address. Synchronization information signal AM25 to obtain the synchronization signal necessary for
．． 26 indicates an address mark indicating the start of address information. If the address signal area 3 of the record carrier 1a moves in the direction of the arrow 28 when the record carrier 1 is rotated, the address mark of the record carrier 1b The signal area 3 moves in the direction of the arrow 29.The record carrier 1 of the present invention is 5M2.
1 and 22, VFO23 and 24 and AM25 and 26 are ID
Since the reading heads are provided symmetrically with 27 in between, when the reading heads are provided above and below the record carrier 1 and the record carrier is rotated, the reading heads provided above and below the record carrier 1 record on the record carriers 1a and 1b. A preferred apparatus using the record carrier 1 of the present invention will be described with reference to FIG. 3. Or even if it shows a block diagram of a device configured to record.
The record carrier 1 is attached to the rotating shaft of a motor 31 and rotated at a predetermined speed.
2 and 33 have exactly the same configuration. The recording and reproducing section 32 is for reproducing the signal recorded on the record carrier 1a, and the recording and reproducing section 33 is for reproducing the signal recorded on the record carrier 1b. A light beam generated from a light source 34 (34') such as a semiconductor laser is made into approximately parallel light by a coupling lens 35 (35') and reflected by a polarizing beam splitter 36 (36'). However, the light beam reflected by the polarizing beam splitter 36 (36") passes through the 1/4 wavelength plate 37 (37"), is converged by the converging lens 38 (38'), and is directed onto the record carrier 1a (
lb) and reflected by the record carrier 1a(lb).
Converging lens 38 (38'), 1/4 wavelength plate 37 (37
'), polarizing beam splitter 36 (36'), convex lens 39 (39'), silundical lens 40 (40'),
) and is irradiated onto the photodetector 41 (4B). The photodetector 41 (4-bit) has four light-receiving areas and detects the defocus of the light beam on the i1 carrier 1a (lb) using the astigmatism method, and detects the focus shift of the light beam on the i1 carrier 1a (lb) using the push-pull method.
b) Even if it is configured to detect the positional deviation between the upper light beam and the track.
Publication No. 39123 Regarding the push-pull method, see the Special Publication No. 5
The converging lens 38 (38') is attached to the control element 42 (42"), and the converging lens 38 (38') is connected to the surface of the record carrier 1 by the control element 42 (42°), which is known from Japanese Patent No. 8-9085, and the explanation thereof will be omitted. Light source 34 (34'), coupling lens 35 (35'), polarized beam Splitter 36 (36'), 1/4 wavelength plate 37 (37''), convex lens 39 (39'), cylindrical lens 40
(40°), photodetector 41 (41') and control element 42
(42') is attached to the transfer table 43 (43''), and the transfer table 43 (43'') is connected to the transfer motor 44 (44').
45 (45'') is configured to be movable in the radial direction of the record carrier 1 by the photodetector 41 (41'), and the information recorded on the record carrier 1a (lb) is reproduced by the photocurrent of the photodetector 41 (41'). Signal A signal processing circuit 45 (4) is a signal processing circuit for obtaining a focus shift signal or a track shift signal.
5°) is the defocus signal, that is, the record carrier 1a (
A signal corresponding to the convergence state of the light beam on lb) is sent to the control circuit 47 (47') via the line 46 (46°), and the control circuit 46 (46') compensates the phase of the focus control system. Drive circuit 48 (48') for power amplification
and drives the control element 42 (42'). Therefore,
The control element 42 (42'') controls the record carrier 1 so that the convergence state of the light beam on the record carrier 1a (lb) is in a predetermined state.
The converging lens 38 (38') is moved in a direction perpendicular to the plane of (this control is called focus control). Further, the signal processing circuit 45 (45'') sends a track deviation signal, that is, a signal corresponding to the positional deviation between the track on the record carrier 1a (lb) and the light beam, to the control circuit 47 (47') via a line 49 (49'). The signal is also sent to the control circuit 46 (46°) ζ to the drive circuit 50 (50') for compensating the phase of the tracking control system and amplifying the power.
Therefore, the control element 38 (38')
is a converging lens 38 (
38') (this control is called tracking control). Further, the control circuit 47 (47') includes a drive circuit 51 for power amplifying the signal obtained by processing the track deviation signal.
(51°) and drives the transfer motor 44 (44°).
') moves around its natural state.
43') (this control is called transfer control).

The signal processing circuit 45 (45') reproduces the signal recorded on the record carrier 1a (1b) and sends this signal to the line 53 (53').
For example, the desired track and sector number of the record carrier 1a, i.e. I
When the D information is input to the control circuit 52, the control circuit 52 reads the ID information of the track where the light beam is located on the record carrier 1a from the signal sent from the signal processing circuit 45. If the current track number is different from the desired track number, control circuit 52 calculates the difference and sends this calculated value to control circuit 47 via line 54. Control circuit 4
7 disables tracking control and transport control, drives the transport motor 44 in accordance with the difference, and moves the transport table 43 in the radial direction of the record carrier 1. After moving the transfer table 43, the control circuit 47 operates the tracking control and transfer control again, and sends an end signal to the control circuit 52.

The control circuit 52 again reads the ID information of the track on which the light beam is located on the record carrier 1a, and checks whether the track number matches the desired track number.If it does not match, the above-mentioned operation is performed. The light beam is repeatedly positioned on the desired track.Then, the sector 1 number is read, and when it is detected that the record carrier 1 has rotated and reached the recording area 4 of the desired sector 1 number, signal reproduction is started. a When recording a signal, the desired track number is searched, the desired recording area 4 is detected, and the intensity of the light beam from the light source 34 is modulated depending on the signal to be recorded. . Further, since the same applies to the case of recording a signal on the record carrier 1b or reproducing a recorded signal, the explanation will be omitted, but the structure of the signal processing circuit 45 will be explained with reference to the block diagram of FIG. 4. .62, 63 and 64 are photodetectors 41
65, 66, 67 and 68 are adder circuits, and the adder circuit 65 is an I/V converter circuit for converting the photocurrent from the four light receiving areas into voltage.
The adder circuit 66 adds the signals of the I/V converter circuits 63 and 64, and the adder circuit 67 adds the signals of the I/V converter circuit 6.
The adder circuit 68 adds the signals of the /V conversion circuits 62 and 64, respectively.69 and 70
is a differential amplifier, and the differential amplifier 69 outputs a signal corresponding to the difference between the signals of the adder circuits 67 and 68, that is, a defocus signal corresponding to the convergence state of the light beam on the record carrier 7. It outputs a signal corresponding to the difference between the signals of the adder circuits 65 and 66, that is, a track deviation signal corresponding to the positional deviation between the light beam and the track on the record carrier 7. The signals of the differential amplifiers 69 and 70 are controlled as shown in FIG. circuit 47
The adder circuit 71 is also sent to ■/V conversion circuit 61.62
．． Add the signals of 63 and 64 and convert this added signal to 2
The binarization circuit 72 compares the signal from the adder circuit 71 at a predetermined level and binarizes it into a HIGH level and a LOW level. The converted signal is sent to the SM detection circuit 7.
4. The recording detection circuit 73 is a circuit that detects that a signal is recorded on the recording area 4 of the record carrier 1a shown in FIG. 1(B). This is done by detecting the envelope of the signal from the circuit 71 and comparing the detected signals at a predetermined level.The PLL circuit 75 is a circuit that generates a reference signal synchronized with the signal from the binarization circuit 72. 75
To briefly explain the configuration, the PLL circuit 75 is composed of a voltage controlled oscillation circuit and a phase comparator.The phase comparator compares the phases of the signal from the binarization circuit 72 and the signal from the voltage controlled oscillation circuit, and compares the phase of the signal from the binarization circuit 72 and the signal from the voltage controlled oscillation circuit. The signal of the voltage controlled oscillation circuit is synchronized with the signal of the binarization circuit 72 by controlling the voltage controlled oscillation circuit with When detected, a period signal for operating the phase control loop is sent to the PLL circuit 75, and the L PLL circuit 75
The phase control loop is operated in response to the signal from the M detection circuit 74, and a reference signal synchronized with the signal from the binarization circuit 72 is sent to the determination circuit 76. The VFO 23 shown in FIG. 2 is provided to facilitate the phase control of the PLL circuit 75. It also determines whether the signal of the conversion circuit 72 is HIGH level or LOW level and sends the determined binary signal to the AM detection circuit 77.The AM detection circuit 77 is a circuit that detects the AM25 shown in FIG. Sends a signal indicating that a mark has been detected to the demodulation circuit 78 and the ID reading circuit 79. Demodulation circuit 7
8 takes in and demodulates the signal from the determination circuit 76 in response to the signal from the AM detection circuit 77, and sends this demodulated signal to the ID reading circuit 79.
The period signal of the 5M detection circuit 74 is for reading the address number and the sector number. Assuming that the record carrier 1 is rotating in the direction of the arrow 28 in FIG. 2, the irradiation position of the light beam on the record carrier 1 needs to be longer than the rotation time from the VFO 23 to the AM 26. If the phase control of the PLL circuit 75 is operated without being recorded, the frequency of the voltage controlled oscillator circuit will be extremely shifted and the pull-in time will be longer.To prevent this! , :, It is desirable that the period signal of the SM detection circuit 74 be shorter than the time from VF○23 to the rear end of 5M22 u% A brief explanation of reproduction of the signal recorded in recording area 4 in FIG. When the recording detection circuit 73 sends a signal indicating that recording is being performed to the PLL circuit 75, the PLL circuit 75
The LL circuit 75 starts phase control and sends a reference signal synchronized with the signal of the binarization circuit 72 to the judgment circuit 76. Determine whether the signal is HIGH level or LOW level.a This determined binary signal is sent to the control circuit 52 71o The track number and sector number read by the ID reading circuit 79 are also sent to the control circuit 52. The control circuit 52 confirms the desired track number and sector number and reads the recorded information from the signal from the determination circuit 76. 8M21.22 in FIG. 2 is generally the recording area 4 in FIG.
Using a special pattern that does not appear in the signal recorded in 4
If the patterns of 5M21 and 22 are the same in chronological order, then 5
Therefore, if the address signal area of the record carrier 1a is moving in the direction of the arrow 28 in FIG. ℃ In this case JiS
Even if the SM detection circuit 74 is configured to use the time difference between M21 and M22 to ignore the sector mark 5M22 after a predetermined time after the first sector mark 5M21 is detected, AM25 in FIG. Similarly, for AM25 and AM26, if a special pattern that does not appear in the signal recorded in recording area 4 in Figure 1 is used and the patterns of AM25 and AM26 are the same in time series, both AM25 and AM26 will be detected. Address mark ie A after a predetermined time after address mark ie AM25 is detected
Even if the AM detection circuit 77 is configured to ignore M26, if the patterns of 8M21 and 5M22 are different, 8M21 and 22 can be easily distinguished.
There is no need to use the time difference between 8M21 and 22 to differentiate them, and the circuit can be simplified. If the patterns of QAM25 and AM26 are made different, it is possible to easily distinguish between AM25 and AM26.
Since the block diagram ζ is the same as the signal processing circuit 45 shown in FIG. 4, the explanation will be omitted.

By making the patterns of 8M21 and 5M22 reverse in chronological order, it is possible to easily distinguish between 15M21 and 8M22, and to detect the sector mark on the record carrier 1b with the SM&output circuit 74 having the same configuration. This will be explained in conjunction with FIG. 5. FIG. 5 shows an example of a sector mark pattern, and FIG. 5(A) shows an 8M21 pattern, and FIG. 5(B) shows an 8M22 pattern.

[F] and [0 in the diagram are hexadecimal representations of the patterns. If the patterns of 5M21 and 8M22 are made to be opposite in time series as shown above, they will be recorded in the direction of arrow 28 in Figure 2. If the address signal area of the carrier 1a is moving, 5M21 is detected L and 5M22 is not detected (t) At this time, the address signal area on the record carrier 1b is
Since it is moving in the direction of 9, 8M22 is detected.
5M21 is not detected. Therefore, the sector mark recorded on the record carrier 1b can be detected by a circuit having the same configuration as the SM circuit 74.
It goes without saying that 2 may be in a symmetrical pattern so that the pattern remains the same even when the record carrier 1 rotates in opposite directions.
The same thing can be said about M25 and M26. For example, if you make it chronologically opposite, A with the same configuration
The address mark recorded on the record carrier 1b can be detected using the M circuit 78. Ma? =AM25
, 26 may be arranged in a symmetrical pattern so that the pattern remains the same even when the record carrier 1 is rotated in opposite directions. Multiple IDs may be lost.
Even if information is recorded, such a case will be explained with reference to Figure 6. Figure 6 is a layout diagram when three pieces of ID information are provided. ID102, ID103
, 104 have the same numbered track and sector number a Sector marks 5M 104 and 105 are provided at both ends h VFO 106 and 107 are provided inside thereof and L'& AM 108 and 109 are VFO 106
,107, AMIIOllll has ID101,
Each is provided inside 103 & 5M104
, VFO 106, AM 108, the record carrier is indicated by arrow 112.
There is also a note when moving in the direction of 5M105
, VFO107, AMI09, the record carrier is arrow 113
This is when the vehicle is moving in the direction of . AMIIO and AMIIII are used to read ID information regardless of direction of movement. 'LAMIIOI;L If the record carrier is moving in the direction of arrow 112, the ID
102 and, if moving in the direction of arrow 113, to read IDI O1. Similar? , :, AM1zζ is used to read ID 103 if the record carrier is moving in the direction of arrow 112 and used to read ID 102 if it is moving in the direction of arrow 113. In this case, it is easy to understand that the sector mark pattern and address mark pattern can be the patterns described above, so the explanation is omitted.Address mark detection CL Count the number within a predetermined period L Ignore the fourth one. Above is a detailed description of the present invention (the present invention shall not be limited in any way by the embodiments), for example, also in the phase encoding (PE) modulation scheme, for reading recorded information. For example, VFO23, 24 and 5M21, 22 shown in FIG. 2 can be omitted if ζ contains the necessary synchronization information.
For example, the address signal area 4 may be recorded using the 2-7 modulation method, and the address signal area 3 may be recorded using the PE modulation method.
It is also possible to record signals using different modulation methods in the recording area 4 and the address signal area 3. Also, the form of the signal recorded in the address signal area may be the same form as the signal recorded in the recording area, or it may be formed by uneven pits (also on the record carrier). The tracks are not limited to a spiral shape, but may be concentric circles (t).
(Read-only memory) Can also be applied to disks
It goes without saying that it can also be applied to disks using magneto-optical materials or organic dye materials instead of phase change materials.
, % Effects of the Invention The record carrier of the present invention can reproduce signals from both sides while the record carrier is rotated by providing read heads on the top and bottom of the record carrier. Signals can also be recorded on both sides. As a result, the online memory capacity can be doubled, and the effect is extremely large. Q: It is possible to reduce the production cost of record carriers extremely low because the disks cut and duplicated using the same cutting machine can be simply pasted together.

[Brief explanation of the drawing]

Figure 1 is an overview of the record carrier of the present invention @ Figure 2 is a layout diagram of signals recorded in the address signal area of the record carrier of the present invention Figure 3 is a diagram of a device suitable for the record carrier of the present invention Block doctor Figure 4 is a block doctor for the signal processing circuit 45 Figure 5 is a sector mark pattern @ Figure 6 is a layout diagram of signals recorded in the address signal area when three pieces of ID information are provided System 1, 1a, 1b...Record carrier 2...Sector,
3...Address signal area 4...Signal recording inclined plate 5.
...Rotation direction of record carrier Name of agent Patent attorney Akira Okaji and two others Figure 4

Claims (11)

[Claims] (1) A double-sided disc-shaped record carrier made by laminating two record carriers of the same format, provided with identification information for identifying the position of the record carrier on a spiral or concentric track, and An optical record carrier characterized in that first and second mark information for detecting the position of the identification information are provided before and after the identification information in the circumferential direction. (2) The optical record carrier according to claim (1), wherein the first and second mark information have the same pattern. (3) The optical recording according to claim (2), characterized in that the pattern is symmetrical so that the patterns of the first and second mark information are the same even when the record carrier is rotated in the opposite direction. carrier. (4) The optical record carrier according to claim 1, wherein the first and second mark information have different patterns. (5) A pattern of first mark information when the record carrier is rotated in the first rotation direction and a pattern of second mark information when the record carrier is rotated in the opposite direction to the first rotation direction. 5. The optical record carrier according to claim 4, wherein the first and second mark information are provided such that the marks are the same. (6) A double-sided disc-shaped record carrier made by pasting together two record carriers of the same format, provided with identification information for identifying the position of the record carrier on a spiral or concentric track; An optical record carrier characterized in that synchronization information for reading the identification information is provided before and after the identification information in the circumferential direction. (7) A double-sided disc-shaped record carrier made by pasting together two record carriers of the same format, which includes identification information for identifying the position of the record carrier on a spiral or concentric track, and the identification information for identifying the position of the record carrier on a spiral or concentric track. First to read information
, second synchronization information, first synchronization signal detection information for detecting the position of the first synchronization information, and second synchronization signal detection information for detecting the position of the second synchronization information. and provided along the track in the order of the first synchronization signal detection information, the first synchronization information, the identification information, the second synchronization information, and the second synchronization signal detection information. An optical record carrier characterized by: (8) The optical record carrier according to claim (7), wherein the first and second synchronization signal detection information have the same pattern. (9) The optical system according to claim (8), characterized in that the pattern is symmetrical so that the patterns of the first and second synchronization signal detection information are the same even when the record carrier is rotated in the opposite direction. Expression record carrier. (10) The optical record carrier according to claim (7), wherein the first and second synchronization signal detection information have different patterns. (11) A pattern of first synchronization signal detection information when the record carrier is rotated in the first rotation direction and a second synchronization when the record carrier is rotated in the opposite direction to the first rotation direction. The first
The optical record carrier according to claim 10, further comprising: and second synchronization signal detection information.