JPH01243253A - Record carrier - Google Patents

Abstract

PURPOSE:To realize the miniaturization and the cost down of a device by detecting the travel speed of a conversion means at a reproducing position and the number of traverses of a track easily at the time of retrieving a desired track on a rotating record carrier and making an external scale, etc., unnecessary by forming a first servo signal and a second servo signal on the record carrier, and enabling the distinction of (n) tracks to be performed. CONSTITUTION:The tracks 3 are formed in spiral shape successively in a direction from the outer periphery to the inner periphery of the record carrier 1, and the tracks are formed by continuous segments 7. Also, the segment 7 is constituted of a servo area 4, a synchronizing signal area 5, and an information area 6 where the information of the address of the track or data, etc., is recorded or to record those information. The data is recorded in a sector unit, and one sector is constituted of the integer number of segments 7, and a track address and a sector address are recorded in advance on every sector in the information area 6, and the travel speed of the conversion means at the reproducing position and the number of traverses of the track can be detected easily.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a record carrier used in an apparatus for reproducing recorded signals or recording signals on the record carrier while rotating the record carrier, and particularly relates to a record carrier used in an apparatus for reproducing recorded signals or recording signals on the record carrier while rotating the record carrier. This invention relates to a disc-shaped record carrier that is intermittently provided with a servo signal for detecting that the reproduction position of a conversion means for reproducing a signal has deviated from a track.

2. Description of the Related Art Conventional record carriers have tracks in which information such as a servo signal area, a synchronizing signal area, and track addresses or data are recorded, or are made up of repeated information areas for recording such information, in a concentric or circular pattern. It is formed in a spiral shape, and the servo signal area is provided with a pair of first and second servo signals for detecting track deviation that are spaced apart in the longitudinal direction of the track and symmetrically shifted with respect to the center of the track, A synchronization signal for detecting the positions of the first and second servo signals is recorded in the synchronization signal area. Further, the first and second servo signals for detecting track deviation are provided so as to be respectively positioned on a straight line passing through the center of the record carrier.

When the device reproduces a signal recorded on a record carrier or records a signal on a track on a record carrier, the track/7 king control is carried out so that the playback position of the converting means is always located above track 2. However, the detection of the track deviation signal necessary for this tracking control is obtained from the first and second servo signals. That is, the first and second servo signals obtained from the conversion means have a predetermined time difference,
When the reproduction position of the converting means is located at the center of the track, the first and second servo signals have the same magnitude, and when the reproduction position shifts from the center of the track, one of the first and second servo signals Since one signal becomes large and the other signal becomes small, the magnitude of both signals is detected, and a positional deviation signal between the reproduction position of the converting means and the track is obtained from the difference between the two signals and tracking control is performed.

Problems to be Solved by the Invention In the above-mentioned conventional record carrier, the first and second servo signals for detecting track deviation are provided so as to be respectively positioned on a straight line passing through the center of the record carrier. When searching for a desired track, if the playback position of the conversion means is moved rapidly in the radial direction of the record carrier, it will not be possible to detect that the track has been crossed. It is necessary to provide a means in the device, which is a significant obstacle to miniaturization and cost reduction of the device.

The present invention eliminates the above-mentioned conventional drawbacks, and enables stable and accurate detection of crossing a track even if the reproduction position of the converting means is moved at high speed in the radial direction of the record carrier when searching for a desired track. It is to provide a record carrier.

Means for Solving the Problems The record carrier of the present invention consists of a servo signal area, a synchronizing signal area, and a repeating information area in which information such as track addresses or data is recorded or for recording such information. The track is formed in a concentric or spiral shape, and the servo signal area includes a pair of first and second servo signals for detecting track deviation that are spaced apart in the longitudinal direction of the track and symmetrically shifted from the center of the track. A synchronization signal area is provided with a synchronization signal for detecting the positions of the first and second servo signals, the servo signal area, the synchronization signal area, and the information area are formed radially, and the track is One servo signal passes through a first track area that is adjacently arranged across N tracks on a first straight line passing through the center of the record carrier and a center of the record carrier different from the first straight line. A second track area in which servo signals of ] are arranged adjacently across N tracks is formed on a second straight line so that the second track area is alternately repeated in the radial direction of the record carrier, and the first track area The second servo signal in the area is formed so that N straight lines connecting the center of the record carrier and the second servo signal do not overlap and are spaced at a predetermined angular interval.
The second servo signal in the first track area is formed so that N tree straight lines connecting the center of the record carrier and the second servo signal do not overlap and are spaced at a predetermined angular interval. The straight line connecting the second servo signal of the second track and the center of the record carrier is the Nth servo signal in the second track area.
The straight line connecting the second servo signal of the Nth track and the center of the record carrier in the first track area overlaps with the straight line connecting the second servo signal of the Nth track and the center of the record carrier. the first in the second track area
It is formed so as to overlap the straight line connecting the second servo signal of the second track and the center of the record carrier.

Operation Since the record carrier of the present invention forms the first servo signal and the second servo signal as described above, it is possible to distinguish between 2N tracks and search for a desired track on the rotating record carrier. In this case, if the reproduction position of the conversion means is at a speed that does not exceed 2N tracks within the rotation period of the area that is the sum of a set of servo signal areas, synchronization signal areas, and information areas, the conversion means can be easily reproduced. The traveling speed of the location and the number of track crossings can be detected.

Embodiment Below, a record carrier according to an embodiment of the present invention will be described in detail with reference to the drawings.

Note that the same numbers are used for the same numbers in the explanation of the drawings.

FIGS. 1A and 1B are external views of a disc-shaped optical record carrier to which the present invention is applied, and are exaggerated for ease of explanation.

(A) is a front view of the record carrier 1, and (B) is a cross-sectional view of the record carrier 1 taken along the dashed line 2.

(A) In the figure, the track 3 is shown only on part of the outer and inner circumferences of the record carrier 1, but in reality it continues in a spiral shape from the outer circumference to the inner circumference of the record carrier 1. The pitch is very fine, for example, 1.5 μM.

Track 3 on record carrier 1 is a continuous part of the track, but for ease of explanation below, a straight line starts from a certain point, goes around record carrier 1, and connects that point to the center of record carrier 1. One spiral unit track is defined as one track until it intersects with .

Segment 7 is the servo signal area 4. A synchronization signal area 5 and an information area 6 in which information such as rack addresses or data is recorded or for recording such information.
Although the segments 7 are only partially shown in Figure (A), the track 3 is actually formed from continuous segments 7.

Data is recorded in units of sectors, and one sector is composed of an integral number of segments 7. Information on record carrier 1
'J area 6 has a track address and a sector address recorded in advance for each sector. For example, 1 sector is 1
If it is composed of 0 segments 7, a track address and a sector address are recorded in the information area 6 of the first segment. Therefore, data is recorded on the information area 6 of the second to tenth segments.

An integral number of segments 7, for example 1200 segments, are formed on one track of the record carrier 1, so that the servo signal area 4. The synchronization signal area 5 and the information @ area 6 are (
A) As shown in the figure, it is radial starting from the center of the record carrier 1.

Furthermore, if the number of sectors on one track of the record carrier 1 is an integral number, the information area 6 in which track addresses and sector addresses are recorded also becomes radial.

As shown in FIG. 1B, the recording carrier 1 is composed of a base material 8, a recording material layer 9, and a protective layer 10 for protecting the recording material layer 9 from dirt, dust, scratches, and the like. A servo signal is provided on the surface 11 of the base material 8 in advance.

A synchronizing signal, a track address, and a sector address are recorded in a concave and convex form, and data is recorded on the recording material layer 9 corresponding to the information area 6.

FIG. 2 shows the record carrier 1 when the number of tracks in the first track area 25 and the second track area 26 is four trees.
This is an enlarged view of a portion of the diagram, in which the dashed line 21 represents the center of the track, the pits 22 represent the first servo signal, the pits 23 represent the second servo signal, and the pits 24 represent the synchronization signal. The arrow 27 indicates the radial direction of the record carrier 1.

Bit 7 of 4 tracks in the first track area 22
A straight line 28 passing through and a straight line 29 passing through the pits 22 of the four tracks in the second track area are formed to pass through the center of the record carrier 1.

The pits 23 of the four trucks in the first track area are formed so that the distances from the pits 22 of the same truck are gradually spaced apart at predetermined intervals, and the pits 23 of the four trucks in the first track area are The pits 23 are formed so that the distance from the pits 22 of the same track gradually approaches each other at predetermined intervals.

Also, the pits 1-23 of the first track in the first track area and the pits 23 of the fourth track in the second track area are on a straight line 30 passing through the center of the record carrier 1.
Pit 23 of the fourth track in the first track area
and pit 2 of the first track in the second track area
3 are formed so as to be located on a straight line 31 passing through the center of the record carrier 1.

All the pits 24 are formed so as to be located on a straight line 32 passing through the center of the record carrier 1.

For example, there are 1200 segments 7 in FIG. 1 formed on a track corresponding to one revolution of the record carrier 1, the number of rotations of the record carrier 1 is 200 ORPM, and the servo signal area 4.
If the ratio of the lengths of the synchronization signal area 5 and the information area 6 is 1:1:8, the rotation time per segment is 25 μs.
, the rotation time per region of the servo signal region 4 and the synchronization signal region 5 is 2.5 μs, respectively.

When the number of tracks in the first track area 25 and the second track area 26 is four each, the number of tracks traversed during a rotation time of 25 μs per segment of the light beam moving in the radial direction of the record carrier is If it is less than 8, it is possible to detect the number of trucks crossing and the moving speed.
If the track pitch is 1.5 μM, the maximum speed V is y=8×1.5/25 10,48 M/S, which is about 16 times that of the conventional case.

When the light beam on the record carrier 1 moves at this maximum speed, the amount by which the light beam moves in the radial direction of the record carrier 1 during the period of the servo signal area 4 is 1.2 μM.

In the present invention, the second servo signal is formed so that false detection of the number of tracks crossed when the light beam moves at maximum speed is minimized. This will be explained below with reference to FIG.

In FIG. 3, the second servo signals of the first track area and the second track area are formed to have exactly the same shape. When the first servo signal 41 and the second servo signal 42 are formed in this way, there is no problem when the light beam moves on the straight line 43, but when the light beam moves on the straight line 44, it is difficult to track the light beam. 45, and a very large error occurs.

On the other hand, in the record carrier of the present invention, such a large error as described above does not occur, and the error is at most one line or less, and highly accurate detection can be performed by averaging or the like.

Since the record carrier 1 of the present invention detects the servo signal area from the synchronization signal 24, it is very important to detect the synchronization signal 24 with high reliability.

In the case of the record carrier 1 shown in FIG. 2, the synchronization signal 24 can be detected from the time from the pit 23, which is the second servo signal.

In the record carrier 1 of FIG. 2, the pits 22 and 23 are interchanged, and the pits 23 and 23 are temporally replaced. Pi 1-22. If the pits 24 are formed in the same order as the pits 24 and the pits 24 are detected based on the time from the pit 22, there will be less temporal change due to the difference in the tracks of the pits 22, so more accurate detection can be achieved.

Furthermore, if another pit is provided in the synchronization signal area 5 in addition to the pit 24, which is located on a straight line passing through the center of the record carrier 1, and the synchronization signal is detected from the time interval between the two focuses, Highly reliable detection can be performed.

Converting 8 bits to 15 channel bits and setting 4 recording marks in the 15 channel focus 4/15
There are two modulation methods, and the record carrier of the present invention using this method will be explained with reference to FIG.

Servo signal area 4 and synchronization signal area 5 are the first byte 5
The pit 22, which is the first servo signal, is connected to the third or fourth channel bit of the first bite 51, and the pit 23, which is the second servo signal, is connected to the first bit. The pit 53, which is the first synchronizing signal, is connected to the 15th channel bit of the first byte 51, and the pit 54, which is the second synchronizing signal, is connected to the 8th to 11th channel bits of the hide 51. The twelfth channel bits are formed respectively.

The pit 22 which is the first servo signal is the first byte 51
The third or fourth channel bit is formed in order to prevent interference by the signal of the immediately preceding information area 6, and the interval between pits 22 and 23 and the interval between pits 23 and 53 are 4 channel bits. The reason for the opening is to prevent interference between these focal points.

Also, when using 4/15 modulation method, the longest mark interval is 1
It is one channel bit, and by setting the interval between pits 53 and pits 54 to 12 channel bits, it is easy to distinguish it from the data recorded in the information area 6.

The reason why the pit 54 is formed in the 12th channel bit of the second byte 52 is to prevent interference by the signal in the information area 6 immediately after.

Pit 24 for synchronization signal in FIG. The synchronizing signal pits 53 and 54 in FIG. The synchronization signal can be detected more reliably.

Further, if the pits 22 and 23 are formed so that the size in the radial direction of the record carrier 1 is in the range of 172 to 374 of the track pitch, and the pit centers are located between the tracks, the pits 22 and 23 can be formed on the record carrier 1. Servo signals can be detected more reliably when the light beam moves at high speed. In addition, it is desirable that signals with irregularities such as pits 22, 23, 24 or other addresses have a depth that is 1/4 of the wavelength of the light beam used to thicken the output of the reproduced signal.

In FIG. 4, the pit 22 and the pit 23 are exchanged without providing the pit 53, that is, the pit 23 is changed from the third channel bit of the first hide to the sixth channel bit, and the pit 22 is changed from the tenth channel bit of the first bite. If the pits 54 are formed in the bits or 11th channel pits 1 to 1 and the pits 54 are detected from the spacing between the pits 22 and 54, the spacing between the pits 22 and 54 becomes 16 channel bits, making it easier to distinguish them from the data. Become.

Although described in detail above, the present invention is not limited to the examples at all.

For example, prerecorded signals such as servo signals, synchronization signals, track addresses, and sector addresses may be formed on the recording material layer 9 of FIG. The number may be greater or less than four.

The present invention is also applicable to read-only optical record carriers, capacitive record carriers, magnetic record carriers, and magneto-optical record carriers on which data is prerecorded in the form of convexes and convexes.

Effects of the Invention Since the record carrier of the present invention forms the first servo signal and the second servo signal as described above, it is possible to distinguish between 2N tracks and select a desired track on the rotating record carrier. When searching for the conversion means, if the playback position of the conversion means is below a speed that does not exceed 2N tracks within the rotation period of the area that is the sum of a set of servo signal areas, synchronization signal areas, and information areas, the conversion means can be easily used. Since it is possible to detect the traveling speed at the playback position and the number of track crossings, there is no need to provide the device with means such as an external scale, and the device can be made smaller and cheaper, which has a very large effect. .

[Brief explanation of the drawing]

FIG. 1 is an external view of a record carrier according to an embodiment of the present invention, FIG. 2 is an enlarged view of the record carrier in FIG. Figure 4 is 4/
FIG. 3 is a diagram showing the formation of a servo signal and a synchronization signal when 15 modulation methods are used. 1... Record carrier, 3... Old track, 4...
...Servo signal area, 5...Synchronization signal area, 6...Information @ area, 22...Pit for first servo signal, 23... ...Pit for second servo signal, 24...Focus for synchronization signal. Name of agent Patent attorney Toshio Nakao (1 person) Track area in Figure 3 1 Which track area

Claims (3)

[Claims] (1) A disk-shaped record carrier in which tracks consisting of intermittent information are formed in a concentric or spiral shape, the information consisting of first and second signals, and the track consisting of the first signal. a first track area in which signals are arranged adjacently across N tracks on a straight line; and a first track area in which signals are arranged adjacently across N tracks on a straight line different from the straight line; second track areas are formed to repeat alternately in the radial direction of the record carrier;
have a predetermined angular interval, and the second signal of the m-th track in the first track area and the second signal of the m-th track in the second track area are different from each other. A record carrier characterized by being arranged in a straight line. (2) The record carrier according to claim 1, wherein the first signal and the second signal are formed between the tracks. (3) The record carrier according to claim (2), wherein the radial size of the record carrier for the first signal and the second signal is 1/2 to 3/4 of the track pitch. .