JP2001357540A - Optical recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retrieve desired tracks at a high speed by detecting the moving speed and moving distance of the light beam on an optical disk with good accuracy even when the light beam moves at a high speed by using the optical disk of a sample servo system. SOLUTION: The servo patterns reproduced by the light beam 22 is identified by a servo pattern identifying circuit 26 from an optical disk 21 formed with the plural serve patterns by varying the arrangement of wobble bits for tracking control by each of the prescribed number of the tracks. The speed under the high-speed movement of the light beam 22 is detected by measuring the timing of the identified servo pattern change. The change direction and number of changes of the servo patterns are detected from the output of the servo pattern identifying circuit 26 by using a direction detection circuit 80 and a counting number circuit 81, by which the detection of the moving speed is made possible even during the high-speed movement of the light beam 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for transferring a light beam to a target track of a record carrier in an optical recording / reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, an optical disc-shaped record carrier (hereinafter, referred to as an optical disc carrier) has been proposed.
An optical disc is abbreviated as a large-capacity data file or a storage medium for music and video data, and is widely used.

In an optical disk device such as a data file,
A light beam generated from a light source such as a laser is converged and radiated onto an optical disk rotating at a predetermined number of revolutions to record and reproduce signals on the optical disk. Fine tracks having a pitch of 0.6 μm are provided concentrically or spirally on the optical disk.

FIG. 14 shows the configuration of this conventional optical disk. FIG. 14A is a perspective view showing the entire configuration. As shown in FIG. 14A, the optical disc 101 is
The recording film 2 is laminated thereon, and spiral virtual tracks 3 and 4 are formed on the recording film 2. One round (360 °) of tracks 3 and 4 is 1280 segments 5
Is divided into During segment 5, FIG.
The servo area 103 and the data area 104 shown in FIG.

FIG. 14B shows a configuration of the servo area 103 and the data area 104. In the servo area 103, the clock pit 105, the first wobble pit 10
Sixth and second wobble pits 107 are formed at predetermined intervals. Information is recorded in the data area 104. The clock pit 105 is used to detect the first wobble pit 106 and the second wobble pit 107, or to generate a synchronous clock signal used for reproducing information recorded in the data area 104.

The first wobble pit 106 and the second wobble pit 107 are shifted from each other by a half track pitch in the radial direction of the optical disc 101 with respect to the center lines of the tracks 3 and 4 in opposite directions. It is arranged and used to detect a tracking error signal indicating a displacement between the light beam on the optical disc 101 and the tracks 3 and 4.

On the other hand, since such an optical disc is provided with a very large number of tracks, a search means is indispensable in order to find a track on which desired information is recorded from a large number of tracks. . Each track on the optical disk is assigned an address number (track address) for specifying its position. Searching for a track on which desired information is recorded is performed based on the track address.

During the search operation, the light beam is moved in the radial direction by a distance corresponding to the difference between the track address being reproduced and the desired track address. The moving distance at this time is
Generally, the number of tracks traversing when the light beam moves is counted and detected.

However, in the case of an optical disc of the type in which a tracking error signal is detected by the first wobble pit 106 and the second wobble pit 107 as described above, when an optical beam passes over a track formed by a guide groove. In order to generate a tracking error signal having a substantially sinusoidal waveform like this, it is necessary that at least several sample points be detected, so if the light beam traverses the track at a high speed, the light beam traverses the track. Things cannot be detected.

Therefore, in the conventional optical disk device, a desired track search is performed by taking measures such as the following 1), 2) and 3). 1) The light beam is transferred at such a low speed that a substantially sinusoidal tracking error signal can be detected from the tracking error signal generated from the wobble pit. 2) In addition to the above-mentioned clock pits and wobble pits, access pits constituting a gray code or the like are added on the optical disk so that the moving state of the light beam can be detected even when the light beam moves at high speed. (Patent No. 2796344
3) A sensor for detecting the moving distance of the optical pickup is provided in the optical disk device, and thereby the moving distance of the light beam is detected.

[0011]

However, in the above-mentioned method 1), it is necessary to constantly move the light beam at a low speed. For example, when information is recorded / reproduced on a desired track on an optical disk, a processing time is required. There is a problem that it takes a long time.

When an access pit is added to the optical disk as in 2), information cannot be recorded and reproduced on the access pit, and the amount of information that can be recorded on the optical disk is reduced by the amount of the access pit. There is a problem.

Further, as described in the above 3), when a sensor for detecting the moving amount of the optical head for generating the light beam is separately provided to detect the moving distance of the light beam, the sensor detects the eccentricity of the optical disk. Since it cannot be performed, a large error occurs in the moving distance of the detected light beam due to the influence of eccentricity or the like. Since it is necessary to perform a search operation again to fill the error, there is a problem that a long processing time is required when searching for a target track and recording and reproducing information.

On the other hand, the present applicant has changed the arrangement of wobble pits for tracking error signal detection every predetermined number of tracks as means for detecting the moving direction of a light beam without sacrificing the recording capacity of an optical disk. (Japanese Patent Application No. 11-236367). Using this optical disk, it is possible to configure an apparatus for searching tracks at high speed in addition to detecting the moving direction of the light beam as described in Japanese Patent Application No. 11-236367.

According to the present invention, an optical disk having wobble pits for detecting a tracking error signal having a specific arrangement is used, the moving speed and the moving distance of a light beam are detected, and a track on the optical disk on which desired information is recorded is reproduced at high speed. It is an object of the present invention to provide an optical recording / reproducing device which can be searched for at a time.

[0016]

In order to solve the above-mentioned problems, an optical recording / reproducing apparatus according to a first basic structure of the present invention comprises a plurality of pits formed on concentric or spiral tracks. A recording carrier on which a plurality of pit patterns are formed by changing the arrangement of at least a part of the plurality of pits for each predetermined number of tracks; a light converging means for converging a light beam on the recording carrier; and a light converging means. Transport means for transporting in the radial direction of the carrier, identifying means for identifying the pit pattern from the reflected light from the record carrier and outputting an identification signal, and a change that has occurred since the previous change was detected by detecting a change in the identification signal Measuring means for measuring time. When the transfer means is driven, the moving speed of the light beam is detected by the measuring means, and the drive of the transfer means is controlled based on the detected moving speed. According to this configuration, even when the light beam is moving at a high speed, it is possible to detect the moving speed of the light beam by changing the wobble pit arrangement.

In the above configuration, preferably, a track cross signal generating means for generating a track cross signal indicating that the light beam has crossed the track, and a speed at which the light beam crosses the track is detected by the track cross signal generating means. A track traversing speed detecting means.
When driving the transfer means, the moving speed detected by the measuring means and the moving speed detected by the track traversing speed detecting means are switched and used. According to this configuration, since the moving speed of the light beam can be detected from the change in the arrangement of the wobble pits and the track cross signal, the optimum moving speed can be detected according to the moving state of the light beam. It is possible to do.

In each of the above arrangements, preferably, when searching for a track for transferring a light beam to an arbitrary target track on a record carrier, when the light beam approaches the vicinity of the target track, the moving speed of the light beam is detected from the measuring means. It is configured to switch to the track crossing speed detecting means. According to this configuration, when the light beam approaches the desired track at the time of the track search, the speed is detected by detecting the crossing speed of the track. And high-accuracy speed control can be realized. If the reproduction position of the light beam is far from the target track, the moving speed is detected by the measuring means, so that the moving speed of the light beam is very high. Can be detected.

Each of the above arrangements preferably includes a reference speed generating means for generating a target transfer speed of the transfer means. Then, when searching for a track for transferring the light beam to an arbitrary target track on the record carrier, if the target transfer speed is higher than a predetermined value, the transfer speed of the light beam is detected by the measuring means, and the target transfer speed becomes higher than the predetermined value. If it is smaller, the traveling speed of the light beam is detected by the track traversing speed detecting means. According to this configuration, when the transfer speed of the light beam is high, the moving speed is detected by the measuring unit, and when the transfer speed of the light beam is low, the speed is detected by the track traversing speed detection unit. It is possible to select an appropriate speed detecting means according to the moving speed of the beam.

In each of the above structures, preferably, the track cross signal generating means is a tracking error detecting means for detecting a tracking error signal indicating a positional shift between the light beam and the track from a signal based on pits formed on the track. And binarizing means. When the tracking error signal is detected at a predetermined level by the tracking error detecting means, the detection of the light beam transfer speed is switched from the measuring means to the track crossing speed detecting means. According to this configuration, a track cross signal when the light beam crosses the track can be generated with a simple configuration,
Since the generation of the tracking error signal can be observed in the track cross signal generation means, it is possible to prevent switching of the speed detection means in the absence of the track cross signal.

In the optical recording / reproducing apparatus according to the second basic configuration of the present invention, a plurality of pits are formed on concentrically or spirally provided tracks, and at least a part of the plurality of pits is arranged by a predetermined number of tracks. A record carrier on which a plurality of pit patterns are formed differently for each, a light converging means for converging a light beam on the record carrier, a transfer means for transferring the light converging means in a radial direction of the record carrier, And a direction detecting means for detecting a moving direction of the light beam from the identification signal, and a counting means for counting the number of changes of the identification signal. When driving the transfer means, the movement distance of the light beam is detected by the direction detection means and the counting means, and the drive of the transfer means is controlled based on the movement distance of the light beam. According to this configuration, even when the light beam is moving at a high speed, the moving distance of the light beam can be detected from the change in the wobble pit arrangement.

In the second basic configuration, preferably,
Track cross signal generating means for generating a track cross signal indicating that the light beam has traversed the track, and track crossing counting means for detecting the number of track traversals of the light beam by the track cross signal generating means. And
When driving the transfer means, the moving distance of the light beam detected by the counting means and the direction detecting means and the moving distance detected by the track crossing counting means are switched and used. According to this configuration, the moving distance of the light beam can be detected by both the change of the pit pattern on the optical disk and the track cross signal. Therefore, the moving distance detection corresponding to the moving state of the light beam is selected and performed. It becomes possible.

In the second basic configuration, preferably,
When searching for a track for transferring a light beam to an arbitrary target track on a record carrier, when approaching the vicinity of the target track,
The detection of the moving distance of the light beam is switched from the counting means and the direction detecting means to the track crossing counting means. According to this configuration, when the light beam approaches the target track at the time of the track search, the moving distance of the light beam is detected by the track traversing counting means, so that the moving distance of the light beam can be accurately determined, for example, for each track. It becomes detectable. In addition, when the reproduction position of the light beam is far from the target track, even if the moving speed of the light beam is very high and a track cross signal cannot be generated from the wobble pit, the moving distance of the light beam is detected from the change in the pit pattern. It is possible to do.

In each of the above-described configurations based on the second basic configuration, preferably, a reference speed generating unit for generating a target transfer speed of the transfer unit is provided. Then, when searching for a track for transferring the light beam to an arbitrary target track on the record carrier,
When the target transfer speed is higher than a predetermined value, the moving distance of the light beam is detected by the counting means and the direction detecting means. When the target transfer speed is lower than the predetermined value, the moving distance of the light beam is detected by the track crossing counting means. It is constituted so that. According to this configuration, when the light beam transfer speed is high, the moving distance of the light beam is detected by the counting means and the direction detecting means, and when the light beam transfer speed is low, the light is transmitted by the track crossing counting means. Since the moving distance of the beam is detected, the moving distance corresponding to the moving speed of the light beam can be detected.

In each of the above-described configurations based on the second basic configuration, preferably, the track cross signal generating means is provided with a tracking error signal indicating a positional shift between the light beam and the track, based on a signal based on pits formed on the track. And a binarizing means for detecting the tracking error. When the tracking error signal is detected at a predetermined level by the tracking error detecting means, the detection of the moving distance of the light beam is switched from the counting means to the track crossing counting means. According to this configuration, the track cross signal when the light beam crosses the track can be generated with a simple configuration, and the generation of the tracking error signal can be observed in the track cross signal generation means. After reliably detecting the generation, the moving distance of the light beam can be detected by the track crossing counting means.

In each of the above configurations based on the second basic configuration, preferably, the moving distance of the light beam is detected by adding the output of the counting means and the output of the track crossing counting means.
This makes it possible to reliably detect the moving distance of the light beam even when the moving speed of the light beam changes frequently, such as when searching for a track that transfers the light beam to an arbitrary target track on the record carrier. Will be possible.

In the optical recording / reproducing apparatus according to the third basic configuration of the present invention, a plurality of pits are formed on concentrically or spirally provided tracks, and at least a part of the plurality of pits is arranged by a predetermined number of tracks. A record carrier in which a plurality of pit patterns are formed differently, a light converging means for converging a light beam on the record carrier, a transfer means for moving the light converging means in a radial direction of the record carrier, An identification means for identifying a pit pattern from the reflected light and outputting an identification signal, and a change detection means for detecting that the output signal of the identification signal has changed. Then, when searching for a track for transferring the light beam to an arbitrary target track on the record carrier, the transfer means is stopped at the timing of the detection signal of the change detection means near the target track.

This configuration makes use of the fact that the target track at the time of retrieval and the switching of the servo pattern near the target track can be defined in a one-to-one correspondence. The transfer of the light beam is performed with the change of the servo pattern as a temporary target track, and once the transfer of the light beam is stopped at this change, the distance from the stop position to the target track is known in advance. It is possible to shift to the next search operation without reading the address of the stop track. As a result, the detection of the moving speed of the light beam and the detection of the moving distance can be performed only from the servo pattern, so that a high-speed target track can be searched with a simple circuit configuration.

In the third basic structure, preferably,
Reference speed generation means for generating a target transfer speed of the transfer means is provided, and the transfer means is stopped when the target transfer speed becomes smaller than a predetermined value and the change detection means outputs a detection signal. According to this configuration, by stopping the transfer means at the change point of the pit pattern after the moving speed of the light beam becomes smaller than the predetermined value, the transfer means can be reliably stopped at the change point of the pit pattern. Becomes possible. Playback device.

Preferably, in each of the above structures, the plurality of pits on the record carrier are composed of first and second wobble pits, and the positions of the first and second wobble pits are different for each predetermined number of tracks. It is composed of This makes it possible to specifically configure a record carrier of the sample servo system in which the pit pattern changes for each predetermined number of tracks.

In each of the above structures, preferably, four types of pit patterns are formed on the record carrier, and the pit patterns change every predetermined number of tracks. This makes it possible to specifically configure a record carrier in which the arrangement of the first and second wobble pits is different for each predetermined number of tracks.

In each of the above structures, preferably, the track on the record carrier is a virtual track configured so that its center line passes between the first and second wobble pits. Thus, the present invention can be applied to a record carrier in which a virtual track is composed of a plurality of pits.

In each of the above structures, preferably, the track on the record carrier is partially constituted by a guide groove having a planar structure, and a pit is formed in the planar structure. Thus, the present invention can be applied to a record carrier having tracks formed by guide grooves.

[0034]

(Embodiment 1) FIG. 1 shows a configuration diagram of an optical disk 21. FIG. 1A is a perspective view showing the entire configuration. As shown in FIG.
Reference numeral 1 denotes a recording film 2 laminated on a substrate 1;
Spiral virtual tracks 3 and 4 are formed thereon. One round (360 °) of the tracks 3 and 4 is divided into 1280 segments 5. The disc center 16 in FIG. 1A is a virtual point located at the center of the optical disc 21.

FIG. 1B shows the structure of the segment 5. In FIG. 1B, reference numeral 11 denotes a clock pit 6 described later (see FIG. 2) and first wobble pits 7a, 7b, 7c,
This is a servo area in which 7d and second wobble pits 8a, 8b, 8c, 8d are formed. Reference numeral 10 in FIG. 1B denotes a data recording area for recording and reproducing information.

FIG. 2 is a diagram schematically showing a state of formation of pits in the servo area 11. The lateral direction on the paper indicates the track circumferential direction, and the light beam moves from left to right on the paper. A clock pit 6 for generating a synchronization signal is provided in the servo area 11 in the traveling direction of the light beam.
And a wobble pit to obtain a tracking signal
7a and 8a (or 7b and 8b, 7c and 8c, 7d and 8d) are provided in order. Wobble pits 7a, 7b, 7c, 7d, 8a, 8
b, 8c and 8d are formed by being distributed radially inward and outward with respect to the center lines of the virtual tracks 3 and 4. The arrangement of the wobble pits 7a, 7b, 7c, 7d, 8a, 8b, 8c, 8d differs between adjacent virtual tracks when viewed along the moving direction of the light beam. , Wobble pits 7a and 8a relative to the virtual track centerline (or
The arrangement of 7b and 8b, 7c and 8c, and 7d and 8d) shows the virtual tracks as 3 and 4, respectively.

As shown in FIG. 2, a plurality of servo pattern areas 12 are arranged in the servo area 11 by the arrangement of the first wobble pits 7a, 7b, 7c, 7d and the second wobble pits 8a, 8b, 8c, 8d. , 13, 14, and 15 are distinguished. The plurality of servo pattern areas are repeatedly arranged in the radial direction of the optical disc in order, and an angle formed by a line connecting the center point 16 and the clock pit 6 and a line connecting the center point 16 and the first wobble pit ( Θ1, θ2 in FIG. 2) or the center point 16
The angle (θ3, θ4 in FIG. 2) formed by the line connecting the clock pit and the line connecting the center point 16 and the second wobble pit is
They are configured to be different from each other.

First servo pattern area 12, second servo pattern area 13, third servo pattern area 1
The fourth and fourth servo pattern areas 15 are formed over n tracks (n is a natural number of 30 or less).

Next, an optical recording / reproducing apparatus according to the present invention for detecting the moving speed of a light beam from an optical disk on which a servo pattern as described above is formed will be described.

FIG. 3 is a block diagram showing a main part of the optical recording / reproducing apparatus of the present invention. In the figure, reference numeral 21 denotes the optical disk shown in FIG. 1, on which a servo pattern shown in FIG. 2 is formed. Reference numeral 24 denotes an optical head for recording information on the optical disk 21 or reproducing information recorded on the optical disk 21. Light generated from a light source (not shown) provided inside the optical head 24 is collected on the optical disk 21 by the objective lens 23. The focus of the objective lens 23 is controlled so that the light beam 22 is brought into a predetermined convergence state on the optical disc 21. However, the focus control is not directly related to the present invention, and thus the detailed description is omitted.

FIG. 4 shows a signal output from the photodetector 25 when the light beam 22 condensed on the optical disk 21 passes over the servo area shown in FIG.

FIG. 4A shows a signal 30 (based on a pit) output from the photodetector 25 when the light beam 22 is located on the center line of the virtual track 3 while passing through the first servo pattern area 12. Signal based on clock pit 6), 3
1 (a signal based on the first wobble pit 7a) and 32 (a signal based on the second wobble pit 8a) are shown. Similarly, FIG. 4B shows a pit-based signal 33 output from the photodetector 25 when the light beam 22 is located on the center line of the virtual track 3 while passing through the second servo pattern area 13. , 34, and 35 are shown in FIG.
FIG. 4 (d) shows signals 36, 37, and 38 based on pits output from the photodetector 25 when they are located on the center line of the virtual track 3 while passing through the third servo pattern area 14.
The signals 39 and 4 based on the pits output from the photodetector 25 when the light beam 22 is located on the center line of the virtual track 3 while the light beam 22 is passing through the fourth servo pattern area 15
0 and 41 are shown, respectively.

The signal based on the pits shown in FIG. 4 is input to the TE generation circuit 29 and the servo pattern identification circuit 26 shown in FIG. 3 to generate a TE (tracking error signal) and to generate servo pattern areas 12, 13, 14, and 15. Is identified.

Next, the servo pattern identification circuit 26 will be described with reference to FIGS.

FIG. 5 is a block diagram showing the configuration of the servo pattern identification circuit 26. FIG. 6 is a waveform diagram for explaining the operation of the servo pattern identification circuit. 6 (A)
(a) shows that the light beam 22 is shifted with respect to the center line of the virtual track 3 in the first servo pattern area 12 shown in FIG.
A signal output from the photodetector 25 when located on the upper side of the drawing is shown. FIG. 6A shows the light beam 22.
Shows a signal output from the photodetector 25 when it is positioned below the center line of the virtual track 3 in the servo pattern area 12 shown in FIG. FIG.
As is clear from (A) (a) and FIG. 6 (B) (a),
The amplitude of the signal 31 based on the first wobble pit and the amplitude of the signal 32 based on the second wobble pit are equal to the light beam 2
It changes according to the positional relationship between 2 and the center line of the virtual track. Accordingly, for example, from the amplitude of the signal based on the first wobble pit (31, 34, 37, 40 in FIG. 4), the signal based on the second wobble pit (32, 35, 38,
By subtracting the amplitude of 41), a tracking error signal can be detected.

On the other hand, the clock pits 6 are arranged so as to be aligned in a line in the radial direction, and the pit width is determined so as to have a predetermined ratio with respect to the spot size of the light beam. Based signal (3 in FIG. 4)
0, 33, 36, and 39) always have a constant amplitude regardless of the reproduction position of the light beam 22.

FIG. 6A (a) or FIG. 6B (a)
Is input to the binarization circuit 45 in FIG.
The amplitude value is compared with the binarization reference value 53 shown in FIG.
The rectangular wave signal shown in (b) of (A) or (B) is output. In the clock pit detection circuit 46 of FIG.
A signal based on the clock pit is detected from the waveform (b) of (A) or (B), and a signal (c) of FIG. 6 (A) or (B) is detected.
The detection signal shown in FIG.
Output to Here, the servo area 1 is located on the optical disk.
1 and the data recording area 10 are alternately arranged in the circumferential direction.
become. Further, since no pits are arranged in the data recording area 10, a signal based on the clock pit can be easily detected by detecting the first pit in the continuous pits as the clock pit.

FIG. 6 shows a timing signal generation circuit 47.
As shown in (d), (e), (f) and (g) of (A) or (B),
After a lapse of predetermined times t1, t2, t3, and t4 (the predetermined times t1, t2, t3, and t4 correspond to timings at which signals based on the first and second wobble pits are output) from the detection signal of FIG. A detection signal is generated, and the logic circuits 48 and 4 shown in FIG.
9, 50 and 51 are output.

FIG. 6 shows a case where the light beam 22 is within the range of the first servo pattern area 12 as described above. At this time, the generation timings of the binary signal (FIG. 6B) and the detection signals (FIGS. 6D and 6F) match, and the logic circuit 48 of FIG. , Logic circuit 4
9 outputs a signal of “0”, a logic circuit 50 outputs a signal of “1”, and a logic circuit of 51 outputs a signal of “0” to the determination circuit 52. In a discriminating circuit 52 constituted by a logic circuit or a microprocessor,
From the output of the logic circuit described above, it is determined that the reproduction position of the light beam 22 is in the first servo pattern area, and a determination signal is output to the speed detection circuit 27 in FIG. Similarly, when the light beam 22 is in the second servo pattern area 13, the generation timings of the binarized signal (FIG. 6B) and the detection signals (FIGS. 6E and 6F) are different. 5, a signal of “0” is output from the logic circuit 48, a signal of “1” is output from the logic circuit 49, a signal of “1” is output from the logic circuit 50, and “0” is output from the logic circuit 51. Is output to the determination circuit 52. When the light beam 22 is in the third servo pattern area 14 and in the fourth servo pattern area 15, it is identified by the same circuit operation.

The discrimination signal output from the servo pattern identification circuit 26 is 1 for the first servo pattern area and 2 for the second servo pattern area.
In the case of the servo pattern area, the area number of the servo pattern area may be directly output as in 2, or each area number may be converted into a predetermined voltage value and output.

FIG. 7 is a block diagram of the speed detection circuit 27. FIG. 8 is a waveform diagram for explaining the function of the speed detection circuit 27. 7 and 8, the speed detection circuit 27 is used.
Will be described.

In FIG. 7, reference numeral 71 denotes a servo pattern change detection circuit composed of a comparator and the like. The servo pattern change detection circuit 71 compares the output of the servo pattern identification circuit 26 with the reference voltages 1/2 * V1, 3/2 * V1, and 5/2 * V1 in FIG. The four signals shown in FIGS. 8B, 8C, 8D, and 8E are output to the timer circuit 72 in parallel.

The timer circuit 72 outputs the time T between A and B in FIG. 8B from the output of the servo pattern change detection circuit 71, for example.
2, or time T3 between C and D in FIG. 8 (c), E and F in FIG. 8 (d)
The time T4 between them and the time T1 between G and H in FIG. 8E are measured and output to the arithmetic circuit 73. The arithmetic circuit 73 is composed of a microprocessor or the like, and sets Tp = track pitch width (the distance between the center line of the virtual track 3 and the center line of the virtual track 4) in advance as the width value (= n * Tp) of the servo pattern area. V = n * Tp / T (T is T1, T2, T3 or T4 described above)
Is calculated, it is possible to detect the moving speed V of the light beam 22. The output of the arithmetic circuit 73 is the amplifier 7
After the sensitivity is adjusted in step 4, the signal is applied to the speed control circuit 61 via the switch 28 in FIG.

The speed control circuit 61 is composed of a filter, an amplifier and the like.
And outputs a signal corresponding to the difference between the outputs to the drive circuit 63. A transfer motor 66 composed of a stepping motor or the like is driven by a drive circuit 63 to transfer the optical head 24, that is, the light beam 22, in the radial direction of the optical disk 21.

As shown in FIGS. 6A and 6B, signals based on the first wobble pit (31, 34, 3 in FIG. 4)
7, 40) and the amplitude of the signal (32, 35, 38, 41 in FIG. 4) based on the second wobble pit is determined by the position between the light beam 22 and the center line of the virtual track 3 (or 4). It changes according to. Therefore, the signal (31, 3 in FIG. 4) based on the first wobble pit is generated by the TE generation circuit 29.
The tracking error signal is detected by subtracting the amplitude of the signal (32, 35, 38, 41 in FIG. 4) based on the second wobble pit from the amplitude of (4, 37, 40). Depending on the configuration of the tracking control system that causes the light beam 22 to follow the center line of the virtual track 3 or 4, the amplitude of the signal (32, 35, 38, 41 in FIG. 4) based on the second wobble pit is used to determine the first wobble. The signal based on the pit (31 in FIG. 4,
34, 37, and 40) may be subtracted. Since the tracking control system is not directly related to the present invention, a detailed description is omitted.

By the way, as shown in FIG.
1 is discretely arranged on the virtual tracks 3 and 4, but when the light beam 22 traverses one virtual track (3, 4) in a time that can pass several servo areas 11, physical It is possible to detect a tracking error signal in the form of a sine wave similar to a light beam traversing a guide groove configured in a similar manner.

FIG. 9A shows a track crossing speed detecting circuit 6.
FIG. 3 is a block diagram showing a configuration of a 0. When the sine wave tracking error signal shown in FIG. 9B is input from the TE generation circuit 29, it is converted by the binarization circuit 75 into a rectangular wave signal shown in FIG. You. The period counter 76 counts from the rising edge U to the falling edge D or the falling edge D to the rising edge U of the rectangular wave signal shown in FIG. Is output to the arithmetic circuit 77 every moment. The arithmetic circuit 77 is composed of a microprocessor or the like, and calculates the time t1 from the rising edge U to the falling edge D, or the falling edge D to the rising edge U from the input count value and the period of the high-speed clock inside the period counter. Time to
t2, and further calculates the track pitch Tp of the optical disk 21.
Thus, the moving speed V of the light beam 22 = Tp / t1 (or Tp /
t2) is calculated and output to the amplifier 78. The amplifier 78 adjusts the sensitivity of the output of the arithmetic circuit 77 and outputs the result to the switch 28.

The amplitude value judging circuit 79 includes the TE generating circuit 29
By observing the amplitude value of the sine-wave tracking error signal output from the controller, it is determined whether the amplitude value of the tracking error signal is equal to or larger than a predetermined value or smaller than the predetermined value. This is because the TE cannot be generated from the first and second wobble pits when the moving speed of the light beam 22 is high, so that the speed detected by the track crossing speed detecting circuit 60 based on the amplitude of the tracking error signal. This is to determine whether the signal can be used. Depending on whether the amplitude value of the tracking error signal is greater than or equal to a predetermined value or less than the predetermined value, the amplitude value determination circuit
Switch.

FIG. 3 shows a search for a desired track.
This will be described with reference to FIG.

As described above, a very large number of tracks are provided on the optical disk 21, and a search means is indispensable to search for a track on which desired information is recorded from the large number of tracks. is there.

A search for a track on which desired information is recorded is performed based on a track address allocated and provided on the track. The track address can be read, for example, by reading a plurality of 1-bit address pits (not shown) formed in a partial area of the segment 5 continuously. Since it does not directly relate to the invention, a detailed description is omitted.

When searching for a track on which desired information is recorded, the light beam is moved in the radial direction of the optical disk by a distance corresponding to the difference between the track address of the track being reproduced and the track address of the desired track. The movement distance at this time is detected by measuring the drive signal of the transfer motor 66 by the movement amount detection circuit 68. The movement amount detection circuit 68 is constituted by a logic circuit or the like, and converts a drive signal of the transfer motor 66 into the number of moving tracks of the light beam 22 and outputs the converted signal. As described above, the transfer motor 66 is constituted by a step motor. In the case of the step motor, since the amount of rotation is determined in advance by one drive signal, the drive signal is easily converted into the number of moving tracks of the light beam 22 from the drive signal. it can.
The detected moving distance (number of moving tracks) of the light beam 22 is input to the control circuit 67.

In the control circuit 67, the difference between the track address being reproduced and the target track address is calculated by being converted into the number of tracks required to transfer the light beam 22, and the value is stored in a register provided in the control circuit 67. It is set in a circuit (not shown). Light beam 2
The moving distance of 2 is converted into the number of tracks from the driving signal of the transfer motor 66 by the moving amount detection circuit 68 and input to the control circuit 67. In the aforementioned register circuit, from the number of tracks set at the start of the search operation,
The number of tracks input from the movement amount detection circuit 68 is decremented every moment. That is, the value of the register circuit indicates the distance between the reproduction position of the light beam 22 and the target track. The value of this register is input to the speed reference generating circuit 62, and the speed reference generating circuit 62 outputs a speed reference signal corresponding to the distance between the reproduction position of the light beam 22 and the target track to the speed control circuit 61.

When the light beam 22 moves toward the target track, the control circuit 67 determines the moving direction of the light beam 22 and outputs a direction command signal to the speed control circuit 61. The speed control circuit 61 determines and drives the rotation direction of the transfer motor 66 based on the direction command signal.

Reproduction position of light beam 22 (search start position)
FIG. 10 shows an example of a speed reference signal when the light beam 22 is transferred to a target track at a distance L from the target track. FIG.
0, the moving speed of the light beam 22 is
Is defined according to the distance between the playback position of the target track and the target track.

In FIG. 10, the distance L is
Represents a relatively long distance from the innermost circumference to the outermost circumference. The speed Vc is a speed at which the track crossing speed detecting circuit 60 can detect a sine wave tracking error signal having a predetermined amplitude.

As shown in FIG. 10, the light beam 22 is initially Vo
It is accelerated to [mm / s] and starts decelerating when it has moved the distance Ls [mm]. Since Vo> Vc in this region, a sinusoidal tracking error signal cannot be detected, and the signal detected by the speed detection circuit 27 is used as the moving speed of the light beam 22 in this region.

When the light beam 22 reaches a distance of Lc [mm] from the target track and the moving speed of the light beam 22 is reduced to Vc, the traverse speed detecting circuit 60 generates a sine wave tracking error signal having a predetermined amplitude. The switch 28 can be switched by the amplitude value determination circuit 79 described above. Thereafter, the traveling speed of the light beam 22 is detected by the track traversing speed detection circuit 60 until it reaches the target track. As described above, when the moving speed of the light beam 22 is high and the tracking error signal cannot be detected, the moving speed of the light beam 22 is detected from the change in the servo pattern.
When the moving speed of the light beam 22 becomes slow and a tracking error signal can be detected, the moving speed of the light beam 22 is detected from the tracking error signal. Therefore, even in an optical disk of a sample servo system that detects a tracking error signal from a wobble pit, the moving speed of the light beam can be detected with high accuracy.

In the above description, an example in which the speed detection system (switch 28) is switched by the track crossing speed detection circuit 60 has been described. As is apparent from FIG. 10, the output of the speed reference generation circuit 62 is higher than Vc. May be configured such that the switch 28 is switched at the point in time when the value becomes small. Further, as described above, since the distance from the target track and the moving speed of the light beam 22 are determined in advance by the speed reference generation circuit 62, the light beam 22 falls within a predetermined range (Lc in FIG. 10) with respect to the target track. Switch 28 when approaching
Can be switched. (Embodiment 2) In Embodiment 2, a method of detecting the moving distance of a light beam using the above-described servo pattern will be described. FIG. 11 is a block diagram of a main part of an optical recording / reproducing apparatus for detecting a moving distance of the light beam 22 from a servo pattern. Elements similar to those in the circuit of FIG. 3 are denoted by the same reference numerals.

In FIG. 11, reference numeral 80 denotes a direction detection circuit;
Is a counting circuit composed of a counter and the like. The operation of the direction detection circuit 80 and the counting circuit 81 will be described with reference to FIG.

The output of the servo pattern identification circuit 26 is supplied to a servo pattern change detection circuit 71 inside the direction detection circuit 80.
, Memory 82 and servo pattern change direction detection circuit 83
Is input to When the servo pattern change detection circuit 71 detects a change in the servo pattern by the above-described circuit operation, the output of the servo pattern identification circuit 26 at that time is stored in the memory circuit 82 and the servo pattern change direction detection circuit 8.
3 At the same time, 1
The output of the servo pattern identification circuit 26 fetched at the timing before the turn is input to the servo pattern change direction detection circuit 83. The servo pattern change direction detection circuit 83 compares the value input from the memory 82 with the value input from the servo pattern identification circuit 26, and detects the change direction of the servo pattern. Specifically, when the value input from the memory 82 is V1 shown in FIG. 8A and the value input from the servo pattern identification circuit 26 is 2 * V1 shown in FIG. The servo pattern change direction detection circuit 83 detects that the beam 22 has moved from the second servo pattern area to the third servo pattern area.

When the light beam 22 moves toward the target track by the search operation described in the first embodiment, the control circuit 67 determines the moving direction of the light beam 22,
A direction command signal is output to the speed control circuit 61 and the movement direction detection circuit 84. The speed control circuit 61 determines and drives the rotation direction of the transfer motor 66 based on the direction command signal.

The moving direction detecting circuit 84 compares the output of the servo pattern change direction detecting circuit 83 with the direction command signal. If the output of the servo pattern change direction detecting circuit 83 and the direction command signal are in the same direction, the servo pattern change At a timing when a signal is output from the detection circuit, a predetermined positive value is set in the counting circuit 81. If the output of the servo pattern change direction detecting circuit 83 and the direction of the direction command signal are opposite, a negative predetermined value is set in the counting circuit 81.

That is, it is understood that by setting the number of tracks constituting each servo pattern area as a predetermined value in the counting circuit 81, the movement distance of the light beam 22 can be detected by converting the moving distance of the light beam 22 into the number of tracks based on a change in the servo pattern. Like. The value counted by the counting circuit 81 is read from time to time by the control circuit 67, and the control circuit 67 controls the output of the speed reference generation circuit 62 based on this value.

On the other hand, since the servo pattern area is composed of 30 or less tracks, when the position detection is performed using the servo pattern area, the position of the light beam at the position other than the boundary between the servo patterns is equal to that of the servo pattern area. It can only be detected with the accuracy of each width. On the other hand, in the search operation,
In order to quickly transfer the light beam 22 onto the target track, highly accurate position detection for each track (especially near the target track) is required.

As a method for realizing high-precision position detection for each track, there are a method using a tracking error signal and a method using a change in servo pattern. First, a method using a tracking error signal will be described.

As described above, during the search operation, the light beam 22 moves in accordance with the speed reference signal shown in FIG. 10, and the moving speed of the light beam decreases to Vc near the target track (for example, in the range of Lc in FIG. 10). Therefore, it is possible to detect a sine wave tracking error signal as described above. The output of the TE generation circuit 29 is binarized by a binarization circuit 86 provided in a track crossing number counting circuit 87 shown in FIG. 12, and a rectangular wave signal shown in FIG. Is output to the counting circuit 85 composed of. The counting circuit 85 counts the rising edge U or the falling edge D shown in FIG. 9C and outputs the result to the control circuit 67 every moment.

As shown in FIG. 12, the track traversing number counting circuit 87 is provided with an amplitude value judging circuit 79. As described above, when the light beam 22 reaches a distance of Lc [mm] from the target track and the moving speed of the light beam 22 is reduced to Vc, the sine wave tracking error of a predetermined amplitude is output from the TE generation circuit 29. A signal is output. This is detected by the above-described amplitude value determination circuit 79, and a detection signal is output to the control circuit 67.

As described above, in the control circuit 67, the difference between the track address being reproduced and the target track address is calculated by being converted into the number of tracks required to transfer the light beam 22, and the value is calculated.
7 is set in a register circuit (not shown) provided inside. When the transfer of the light beam 22 toward the target track is started, the value of the counting circuit 81 is subtracted from the register circuit. The output of the speed reference generating circuit 62 changes according to the value of the register circuit, and the transfer speed of the light beam 22 decreases as shown in FIG.
When the tracking error signal having a predetermined amplitude and a sine wave shape can be detected, the detection signal of the amplitude value determination circuit 79 provided in the track crossing number counting circuit 87 is input to the control circuit 67. . Therefore, the value of the register circuit is decremented according to the value of the counting circuit 85.

As described above, when the moving speed of the light beam 22 is too fast to detect the tracking error signal, the moving distance of the light beam 22 is detected from the change in the servo pattern, and the moving speed of the light beam 22 is reduced. When the tracking error signal can be detected later, the moving distance of the light beam 22 is detected from the tracking error signal.
The moving distance of the light beam 22 can be detected with high precision from an optical disk of a sample servo system that detects a tracking error signal from a wobble pit.

In the above, an example has been described in which the detection of the moving distance is switched from the servo pattern to the tracking error signal by the track traversing number counting circuit 87. As is clear from FIG. The configuration may be such that the detection of the moving distance is switched from the servo pattern to the tracking error signal when the value becomes smaller than Vc. As described above, the relationship between the distance from the target track and the moving speed of the light beam 22 is determined by the speed reference generating circuit 62.
The light beam 22
It is also possible to switch the detection of the moving distance from the servo pattern to the tracking error signal when the target approaches a predetermined range (Lc in FIG. 10) with respect to the target track. (Embodiment 3) In Embodiment 3, a method of detecting the moving distance of the light beam 22 using the transition of the servo pattern will be described.

Since the switching of the servo pattern is fixed on the optical disk 21, when a certain specific track is designated, the switching of the servo pattern closest to that track is determined in one way (the target track is the servo pattern area). If the light beam 22 is located just in the middle of the target track, there may be two transitions closest to the target track. Is possible). Therefore, it is possible to select a switching point of the servo pattern near the true target track as a (temporary) target track as the target track at the time of the search operation.

FIG. 13 is a block diagram of an optical recording / reproducing apparatus for transferring the light beam 22 to a target track by using the switching of the servo pattern.

In the control circuit 67, the address of the track corresponding to the switching point of the servo pattern close to the target track is calculated from the address of the target track. In addition, the number m of switching points of the servo pattern existing between the track currently being reproduced by the light beam 22 and the calculated address is calculated. The calculation results are set in an internal register (not shown). The difference between the actual target track and the track corresponding to the transition point of the target servo pattern is set in a second register (not shown) provided in the control circuit 67.

When the transfer of the light beam 22 (ie, the transfer of the optical head 24) to the target track (the track at which the servo pattern switches) is started, the value of the counting circuit 81 is subtracted from the register circuit, and The output of the speed reference generator 62 changes according to the value of the circuit.

On the other hand, as described above, the moving speed of the light beam 22 is also detected from the change in the servo pattern. The speed control circuit 61 drives the drive circuit 63 according to the difference between the output of the speed detection circuit 27 and the output of the speed reference generation circuit 62, and controls the rotation speed of the transfer motor 66. That is, the moving speed of the light beam 22 changes following the output of the speed reference generating circuit 62.

As shown in FIG. 10, the speed reference generating circuit 62
Is defined to be 0 on the target track, the rotation speed of the transfer motor 66 also becomes 0, and the transfer of the optical head 24 stops.

Also, depending on the transfer state of the optical head 24,
Even when the gain of the speed control circuit is equivalently reduced and the output of the speed reference generating circuit 62 becomes 0, the rotation speed of the transfer motor 66 may not be reduced to 0. Alternatively, the drive circuit 63 may be forcibly turned off by the control circuit 67.

Simultaneously with the stop of the transfer motor 66, the tracking control circuit 88 is operated to cause the light beam 22 to follow the switching track of the target servo pattern.

The number of tracks between the track at which the light beam 22 is following the servo pattern and the true target track is stored in the second register of the control circuit 67.
, The track jump circuit 89 is operated by the number set in the second register, so that the light beam 22 becomes true even if the address of the track is not read by a signal processing circuit (not shown) or the like. On the target track.

The track jump circuit 89 intermittently disables the tracking control circuit 88, and accelerates and decelerates the objective lens 23 when the tracking control circuit 88 is inoperative, thereby transferring the light beam 22 to an adjacent track. Circuit for

As described above, the search operation is performed using the switching point of the servo pattern as a temporary target track, whereby
After the movement of the transfer motor 66 is completed, it is possible to shift to the jumping operation without reading the track address, and it is possible to reduce the time required for the search operation to the target track. Further, since it is possible to detect both the moving speed of the light beam and the moving distance from the servo pattern, the circuit can be simplified.

In the above description, the case where the rotation speed of the transfer motor 66 is not sufficiently reduced at the switching point of the target servo pattern, but no significant fluctuation occurs in the objective lens 23 even if the stop is forcibly stopped. .

Further, when the speed of the transfer motor 66 is high, if the motor is forcibly stopped, an impact is applied to the objective lens 23 and the tracking control system or the like may become unstable. In such a case, the target track (the switching point of the servo pattern) may be moved until the speed at which no impact or the like is generated on the objective lens 23. In this case, the control circuit 67 stores the number of passed servo pattern transitions, converts the number of tracks to the number of tracks, and sets the number in the above-described second register. It is possible to

The present invention is not limited at all by the above embodiment. In the above-described embodiment, the description has been made using the disk in which the clock pit and the first and second wobble pits are formed on the virtual track. However, the track is configured by the guide groove, and a part of the guide groove is formed in a plane. An optical disk having a clock pit and first and second vobble pits formed thereon may be used, or the clock pit may be omitted so as to obtain a wobble pit detection timing by using a portion that becomes flat from the groove. An optical disk may be used.

In the above embodiment, the angle formed by the line connecting the center point 16 and the clock pit 6 and the line connecting the center point 16 and the first wobble pit (θ1, θ2 in FIG. 2), or the center point 16 Line connecting clock pit and center point 1
6 and the second wobble pit have different angles (θ3, θ4 in FIG. 2), but the physical width of the segment 5, the clock pit 6, the first and second wobble pits, The physical interval between wobble pits of the optical disc 2
It may be configured at a uniform interval over the entire area.

In the above embodiment, an example in which a stepping motor is used as the transfer motor has been described. However, a DC motor or a linear motor can be used as the transfer motor.

In the above embodiment, the operation has been described using the search operation for searching for the target track on the optical disk. However, the light beam is transferred at a constant speed as when the optical recording / reproducing apparatus is started. In this case, it is also possible to detect the moving speed and the moving distance by using a servo pattern.

Further, in the above-described embodiment, a circuit for transferring a light beam one by one has been described as a track jump circuit. However, a multi-track jump for executing a multi-track jump for moving a large number of tracks at once is described. A circuit may be used.

[0100]

According to the optical recording / reproducing apparatus of the present invention, since the moving speed of the light beam is detected from the change in the servo pattern, the light beam moves so fast that a tracking error signal cannot be formed on the sample servo type optical disk. In such a case, it is also possible to detect the moving speed of the light beam.

Further, according to the present invention, the speed detection using the change in the servo pattern and the speed detection using the tracking error signal are switched in accordance with the moving speed of the light beam to cope with the moving state of the light beam. It is possible to perform optimal speed detection.

According to the present invention, in order to detect the transfer distance of the light beam from the change in the servo pattern, the light beam is moved in the direction opposite to the desired movement direction by the influence of the disk eccentricity during the transfer of the light beam. Also in this case, since this is detected and corrected, the transfer distance of the light beam can be accurately measured.

In the present invention, when the moving speed of the light beam is too fast to detect the tracking error signal, the moving distance of the light beam is detected from the change in the servo pattern.
When the moving speed of the light beam becomes slow and a tracking error signal can be detected, the moving distance of the light beam is detected from the tracking error signal.
When searching for a target track, position detection is performed with a relatively coarser accuracy than the servo pattern while the light beam is moving at a high speed, and when the light beam approaches the target track and becomes slower, the position is detected with the accuracy of each track from the tracking error signal. Therefore, it is possible to secure the optimum position detection accuracy according to the moving state of the light beam during the search operation.

Further, according to the present invention, it is possible to perform a search operation using a break point of a servo pattern as a temporary target track. As a result, once the movement of the light beam by the transfer motor is completed, it is possible to shift to the jumping operation without reading the track address, thereby reducing the time required for the search operation to the target track. become. Further, since it is possible to detect both the moving speed of the light beam and the moving distance from the servo pattern, the circuit can be simplified.

As described above, according to the present invention, since the moving speed and moving distance of the light beam can be detected from the optical disk for the sample servo, an arbitrary target track on the optical disk of the sample servo system can be searched at high speed. It is possible to

[Brief description of the drawings]

FIG. 1A is a perspective view showing an entire configuration of an optical disc,
(b) Diagram showing the structure of the segment

FIG. 2 is a diagram schematically showing the arrangement of pits in a servo area.

FIG. 3 is a block diagram of an optical recording / reproducing apparatus according to Embodiment 1 of the present invention.

FIG. 4 is a diagram showing a signal output from a photodetector when a light beam focused on an optical disk passes over a servo area.

FIG. 5 is a block diagram showing a configuration of a servo pattern identification circuit in the apparatus shown in FIG. 3;

FIG. 6 is a diagram showing signal waveforms and the like when a light beam reproduces a first servo pattern area shown in FIG. 2;

FIG. 7 is a block diagram of a speed detection circuit in the device of FIG. 3;

FIG. 8 is a waveform chart for explaining the function of the speed detection circuit of FIG. 7;

9A is a block diagram showing a configuration of a track traversing speed detection circuit in the apparatus shown in FIG. 3, FIG. 9B is a waveform diagram showing a tracking error signal output from a TE generation circuit, and FIG. Diagram showing a simplified tracking error signal

FIG. 10 is a diagram illustrating an example of a speed reference signal.

FIG. 11 is a block diagram showing an optical recording / reproducing apparatus according to Embodiment 2 of the present invention.

FIG. 12 is a block diagram showing a configuration of a direction detection circuit, a counting circuit, and a track crossing number counting circuit in the apparatus of FIG. 11;

FIG. 13 is a block diagram showing an optical recording / reproducing apparatus according to Embodiment 3 of the present invention.

FIG. 14 is a diagram showing a configuration of a conventional optical disk.

[Explanation of symbols]

Reference Signs List 1 substrate 2 recording film 3, 4 virtual track 5 segment 6 clock pit 7a, 7b, 7c, 7d first wobble pit 8a, 8b, 8c, 8d second wobble pit 10 data recording area 11 servo area 12 first Servo pattern area 13 Second servo pattern area 14 Third servo pattern area 15 Fourth servo pattern area 16 Virtual point located at the center of optical disk 21 Optical disk 22 Light beam 23 Objective lens 24 Optical head 25 Optical detection Instrument 26 Servo pattern identification circuit 27 Speed detection circuit 28 Switch 29 TE generation circuit 30, 33, 36, 39 Signal based on clock pit 31, 34, 37, 40 Signal based on first wobble pit 32, 35, 38, 41 Signal 45, 75, 86 based on second wobble pit Binarization Road 46 Clock pit detection circuit 47 Timing signal generation circuit 48, 49, 50, 51 Logic circuit 52 Discrimination circuit 53 Binarization reference value 60 Track crossing speed detection circuit 61 Speed control circuit 62 Speed reference generation circuit 63, 90 Drive circuit 64 Spindle motor 65 Guide shaft 66 Transfer motor 67 Control circuit 68 Movement amount detection circuit 71 Servo pattern change detection circuit 72, Timer circuit 73, 77 Operation circuit 74, 78 Amplifier 76 Period counter 79 Amplitude value judgment circuit 80 Direction detection circuit 81, 85 Counting circuit 82 Memory circuit 83 Servo pattern change direction detecting circuit 84 Moving direction detecting circuit 87 Track traversing number counting circuit 88 Tracking control circuit 89 Track jump circuit 91 Tracking coil 101 Conventional optical disk 03 servo area 104 data area 105 clock pit 106 first wobble pits 107 second wobble pit

Continued on the front page F term (reference) 5D088 BB02 CC04 PP02 RR08 SS05 TT04 5D090 AA01 BB04 CC12 CC16 DD03 FF02 GG02 GG09 GG22 5D117 AA02 AA09 BB04 EE20 FF14 FF15 FF25 FF26 FF29

Claims (17)

[Claims] A plurality of pits are formed on concentrically or spirally provided tracks, and a plurality of pit patterns are formed by changing the arrangement of at least a part of the plurality of pits for each predetermined number of tracks. A record carrier;
A light converging means for converging a light beam on the record carrier, a transfer means for moving the light converging means in a radial direction of the record carrier, and identifying the pit pattern from the reflected light from the record carrier to generate an identification signal. Identification means for outputting, and a measurement means for detecting that the identification signal has changed and measuring a change time elapsed from the time of the previous change detection, and when driving the transfer means, the light from the measurement means An optical recording / reproducing apparatus, wherein a moving speed of a beam is detected, and the driving of the transfer means is controlled based on the moving speed. 2. A track cross signal generating means for generating a track cross signal indicating that a light beam has crossed a track, and a track crossing speed detecting means for detecting a speed at which the light beam crosses the track by the track cross signal generating means. 2. The apparatus according to claim 1, further comprising: means for switching between a moving speed detected by the measuring means and a moving speed detected by the track crossing speed detecting means when driving the transferring means. Optical recording / reproducing device. 3. A track search for transferring a light beam to an arbitrary target track on a record carrier, wherein when the light beam approaches the vicinity of the target track, the moving speed of the light beam is detected by measuring means to determine the track crossing speed. 3. The optical recording / reproducing apparatus according to claim 2, wherein the apparatus is switched to a detecting unit. 4. A reference speed generating means for generating a target transfer speed of the transfer means, wherein the target transfer speed is larger than a predetermined value when searching for a track for transferring a light beam to an arbitrary target track on a record carrier. 4. The method according to claim 2, wherein the detecting means detects the light beam transfer speed from the measuring means, and detects the light beam transfer speed from the track traversing speed detecting means when the target transfer speed is smaller than a predetermined value. An optical recording / reproducing apparatus as described in the above. 5. A tracking error detecting means for detecting a tracking error signal indicating a positional deviation between a light beam and a track from a signal based on a pit formed on a track, and a binarizing means. When the tracking error signal is detected at a predetermined level by the tracking error detection means, the detection of the transfer speed of the light beam is performed by switching from the measurement means to the track traversing speed detection means. Claims 2-4
The optical recording / reproducing apparatus according to any one of claims 1 to 4. 6. A plurality of pits are formed on tracks provided concentrically or spirally, and a plurality of pit patterns are formed by disposing at least a part of the plurality of pits for every predetermined number of tracks. A record carrier;
A light converging means for converging a light beam on the record carrier, a transfer means for moving the light converging means in a radial direction of the record carrier, and identifying the pit pattern from the reflected light from the record carrier to generate an identification signal. Identification means for outputting, direction detection means for detecting the moving direction of the light beam from the identification signal, and counting means for counting the number of changes in the identification signal, when driving the transfer means, Detecting the moving distance of the light beam from the detecting means and the counting means,
An optical recording / reproducing apparatus, wherein the driving of the transfer means is controlled based on the moving distance of the light beam. 7. A track cross signal generating means for generating a track cross signal indicating that a light beam has traversed a track, and a track crossing counting means for detecting the number of light beam traversals by the track cross signal generating means. 7. The apparatus according to claim 6, wherein when driving the transfer means, the moving distance of the light beam detected by the counting means and the direction detecting means and the moving distance detected by the track crossing counting means are switched and used. An optical recording / reproducing apparatus as described in the above. 8. When searching for a track for transferring a light beam to an arbitrary target track on a record carrier, detecting a movement distance of the light beam when approaching the vicinity of the target track.
8. The optical recording / reproducing apparatus according to claim 7, wherein the counting means and the direction detecting means are switched to track crossing counting means. 9. A method according to claim 8, further comprising: a reference speed generating means for generating a target transfer speed of the transfer means, wherein the target transfer speed is higher than a predetermined value when searching for a track for transferring the light beam to an arbitrary target track on the record carrier. Detecting the moving distance of the light beam by the counting means and the direction detecting means, and detecting the moving distance of the light beam by the track crossing counting means when the target transfer speed is smaller than a predetermined value. 9. The optical recording / reproducing apparatus according to 7 or 8. 10. A tracking error detecting means for detecting a tracking error signal indicating a positional deviation between a light beam and a track from a signal based on pits formed on the track, and a binarizing means. Wherein when the tracking error signal is detected at a predetermined level by the tracking error detecting means, detection of the moving distance of the light beam is performed by switching from the counting means to the track crossing counting means. Item 10. The optical recording / reproducing device according to any one of Items 7 to 9. 11. The optical recording / reproducing apparatus according to claim 7, wherein the moving distance of the light beam is detected by adding the output of the counting means and the output of the track crossing counting means. apparatus. 12. A recording in which a plurality of pits are formed on concentrically or spirally provided tracks, and a plurality of pit patterns are formed by changing the arrangement of at least a part of the plurality of pits by a predetermined number of tracks. A carrier;
A light converging means for converging a light beam on the record carrier, a transfer means for moving the light converging means in a radial direction of the record carrier, and identifying the pit pattern from the reflected light from the record carrier to generate an identification signal. Identification means for outputting, and a change detection means for detecting that the output signal of the identification signal has changed, and when searching for a track for transferring the light beam to an arbitrary target track on a record carrier, a search is performed in the vicinity of the target track. An optical recording / reproducing apparatus, wherein the transfer unit is stopped at a timing of a detection signal from the change detection unit. 13. A reference speed generating means for generating a target transfer speed of the transfer means, wherein the transfer means is stopped when the target transfer speed becomes smaller than a predetermined value and a change detection means outputs a detection signal. 13. The method according to claim 12, wherein
An optical recording / reproducing apparatus as described in the above. 14. A plurality of pits on a record carrier, wherein:
14. The apparatus according to claim 1, further comprising a second wobble pit, wherein the positions of the first and second wobble pits are different for each predetermined number of tracks. 15. Optical recording / reproducing device. 15. The optical recording / reproducing apparatus according to claim 1, wherein four types of pit patterns are formed on the record carrier, and the pit patterns change every predetermined number of tracks. apparatus. 16. A track according to claim 1, wherein the track on the record carrier is a virtual track whose center line passes through the middle between the first and second wobble pits.
16. The optical recording and reproducing apparatus according to 4 or 15. 17. The track on a record carrier is formed of a guide groove having a planar structure in a part thereof, and pits are formed in the planar structure.
17. The optical recording / reproducing device according to any one of items 16 to 16.