JP2000200417A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a prescribed track to be established by discriminating, on the basis of the output signal of light quantity detection, whether the address part with a light beam passed is on the outer or the inner periphery with respect to the center of the information track, and by reproducing and recording based on the address polarity discrimination result and the address information. SOLUTION: An address read circuit 52 obtains address information based on the output of a differential amplifier 24, while an address polarity discrimination circuit 51 generates an address polarity discrimination signal based on that output. An address information establishing circuit 53 establishes the address of a track on which a light beam is scanning, on the basis of the address polarity discrimination signal and the output of the address information read circuit 52. If the address information read circuit 52 can obtain both pieces of the address information arranged in zigzag, the central processing unit CPU 54 or the like uses the output result of the address information establishing circuit 53 as it is; if the read circuit 52 can obtain only one piece of the information, the establishing circuit 53 refers to the address polarity discrimination signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus for optically reproducing a signal on an information carrier or recording a signal on the information carrier by using a light beam from a light source such as a semiconductor laser, and more particularly, to an optical disk apparatus. Staggered (wobble)
The present invention relates to a recordable disc reproducing (or recording) apparatus having an address portion arranged in the same manner as described above.

[0002]

2. Description of the Related Art CD-AUDIO, CD-ROM, DV
Information carriers (optical disks) such as D-VIDEO and DVD-ROM have information recorded in the form of concavo-convex pits and the same track from the inner periphery to the outer periphery in a spiral manner.

In order to reproduce the signal on this track,
In a conventional optical disk device, generally, a rotation control for rotating the optical disk at a predetermined rotation speed, a focus control such that a light beam irradiated on the optical disk is brought into a predetermined convergence state, and a light beam on a track on the optical disk correctly. Tracking control such as scanning is performed.

In recent years, with the improvement of high-density optical disk technology, a recordable optical disk DVD-RAM (DIGIT
AL VERSATILE DISC-RANDOM
ACCESS MEMORY) disk (hereinafter referred to as DVD-RAM).

[0005] Such a recordable DVD-RAM is
The structure has an address part and a recordable data part. Further, such a recordable optical disk is divided from the inner periphery to the outer periphery of the optical disk by a plurality of zones on a slice, and the data portion is formed by a land and a guide groove called a groove.

As shown in FIG. 11, the data portion includes a groove track 207 which is a concave portion and a land track 2 which is a convex portion.
The address track 205 is formed between the groove track 207 and the land track 206. The beam on the actual disk is larger than the track width. When the beam follows the groove track 206 or the land track 207, it is possible to read the address information of the address section 205 between the tracks.

[0007] The address 200 is formed between the track 209 and the track 202. The address 201 is formed between the track 202 and the track 203. The address 204 is formed between the track 203 and the track 208. Adjacent tracks share an address.

A track 202 is determined by an address 200 and an address 201, and a track 203 is defined by an address 2
01 and the address 204. By searching this address, the recorded data can be reproduced or recorded on a predetermined track.

[0009] A conventional spiral track composed of a pit row such as a CD or DVD-ROM is not divided by zones, and has the same recording density at a constant linear velocity from the inner circumference to the outer circumference. ing. Therefore, in such a disk, if only the CLV control is operated correctly, the PLL can be pulled in and the address or data can be read.

However, in the case of an optical disk such as a DVD-RAM, the data area is formed in the shape of land and groove guide grooves and is divided by zones.
Depending on the zone, the zone designation is required to set the rotation speed and the PLL target clock.

In general, a stepping motor, an encoder and the like are used in a traverse drive system of an optical head of an optical disk recording apparatus. For example, if you use an encoder,
By controlling the traverse by managing the encoder pulse from the position of the innermost circumference as an initial value, it is possible to construct a system that can recognize in which zone the light beam is currently located.

However, from the viewpoint of accuracy and cost, it is desired to use a DC motor which is cheaper and has a simple structure.

[0013]

When a DVD-RAM disc is reproduced by the above-described conventional optical disc apparatus, one track (land or groove) is determined by a pair of addresses between tracks. . For example, if dust is attached to the address portion of the address 200 or the light beam causes a lens shift and moves in the direction of the arrow N in the figure, the address information of the address 200 cannot be read. In this case, it is impossible to determine whether the track is the track 202 or the track 203, so that data cannot be read or recorded.

In the conventional optical disk apparatus, since the position of the light beam is not known in the initial state of the apparatus, the number of rotations of each zone and the target frequency of the PLL are sequentially switched so that the zone where the address can be read is read. Since it can be determined for the first time, it took a very long time to start up the device.

An object of the present invention is to enable a predetermined track to be determined even if the address on one side cannot be read due to dust adhering to an address portion or a lens shift, thereby reproducing data recorded there. Another object of the present invention is to provide an optical disk device capable of recording data on a predetermined track.

Another object of the present invention is to provide an optical disk apparatus which can reduce the time until an address can be read by estimating the position (zone) where the current light beam is located at the time of starting and restarting the optical disk apparatus. To provide.

Still another object of the present invention is to provide an optical disk device which can be configured with high reliability and at a low cost even for an optical disk divided into zones.

[0018]

According to the present invention, there is provided an optical disk apparatus comprising: a data portion which is an information track formed by a concave-convex guide groove capable of recording and reproducing information; and a position which is a predetermined distance from the center of the information track. A light beam irradiating a light beam onto an information carrier having an address portion formed on the information track and having at least one address information corresponding to the information track recorded in uneven pits, to detect information recorded on the information track; Means, based on a signal output by the light amount detection means, the address portion through which the light beam has passed is located on the outer peripheral side or the inner peripheral side with respect to the center of the information track scanned by the light beam. Address information for reading the address information recorded in the address section based on a signal output from the light quantity detecting means. Reading means, and address information determining means for determining the data portion to be reproduced and recorded based on the determination result of the address polarity determining means and the address information read by the address reading means, comprising: This achieves the above object.

The address section includes two or more address areas in which the address information is recorded. The address areas are arranged in a staggered manner at a predetermined distance from the center of the information track, and are adjacent to each other. The information track
The address area may be shared.

Another optical disc apparatus according to the present invention is a data section, which is an information track formed by an uneven guide groove capable of recording and reproducing information, and a data section formed at a position at a predetermined distance from the center of the information track. Light amount detecting means for irradiating a light beam onto an information carrier having an address portion in which address information corresponding to an information track is recorded in one or more uneven pits to detect information recorded on the information track; Address part detection means for detecting that the light beam is on the address part based on the output of the light quantity detection means, and based on the output of the address part detection means,
A pulse interval measuring unit that measures the interval of the address unit, and a radial position estimating unit that estimates a radial position of the light beam based on a measurement result of the pulse interval measuring unit.
Clock generating means for generating a reproduction clock based on the radial position estimated by the radial position estimating means, whereby the object is achieved.

The optical disk apparatus further includes a track shift detecting means for detecting a track shift amount of the light beam when passing through the address section, wherein the address section detecting means outputs the output of the track shift detecting means to a binary value. The pulse interval measuring means measures an interval between output pulses of the binarizing means, and the radial position estimating means measures a time for one rotation of the information carrier and the pulse interval. The radial position of the light beam may be estimated based on the output of the means.

The optical disk device includes a track shift detecting means for detecting a track shift amount of the light beam when passing through the address section, and a maximum for measuring a maximum value of an output signal of the track shift detecting means within a predetermined time. Value measuring means, and a minimum value measuring means for measuring a minimum value of an output signal of the track shift detecting means within a predetermined time, wherein the address section detecting means binarizes an output of the track shift detecting means. Binarizing means, and binarizing the output of the track deviation detecting means to a predetermined ratio with respect to the maximum value outputted by the maximum value measuring means and the minimum value outputted by the minimum value measuring means. Threshold setting means for setting a threshold for performing the setting.

The optical disc device includes a track shift detecting means for detecting a track shift amount of the light beam when passing through the address section, and a maximum for measuring a maximum value of an output signal of the track shift detecting means within a predetermined time. Value measuring means, minimum value measuring means for measuring a minimum value of an output signal of the track deviation detecting means within a predetermined time, and average value measurement for measuring an average value of output signals of the track deviation detecting means within a certain time Means, the address portion detecting means includes a binarizing means for binarizing an output of the track deviation detecting means, the maximum value output by the maximum value measuring means, and the minimum value measuring means. A binarizing means for binarizing the output of the track deviation detecting means at a predetermined ratio with respect to the minimum value to be outputted, based on the output of the average value measuring means; It may include a threshold setting means for setting a have value.

The optical disc apparatus includes a track shift detecting means for detecting a track shift amount of the light beam when passing through the address section, and a maximum for measuring a maximum value of an output signal of the track shift detecting means within a predetermined time. Value detecting means, and an amplitude absolute value converting means for obtaining an absolute value of an amplitude of an output signal of the track shift detecting means, wherein the address portion detecting means binarizes an output of the track shift detecting means. Thresholding means for setting a threshold for binarizing the output of the track deviation detecting means at a predetermined ratio with respect to the maximum value output by the maximum value measuring means. May be included.

When measuring the output pulse of the binarizing means, the pulse interval measuring means invalidates the output pulse output after the output pulse continuously output for a shorter time than a predetermined period. Then, the interval of the output pulse may be measured.

[0026] The optical disc apparatus may further comprise: tracking control means for controlling the light beam so that the light beam scans the track on the information carrier; and that the optical disc device deviates from the track scanned by the light beam. The optical disc apparatus may further comprise a track flow detecting means for detecting, and the optical disc apparatus may deactivate the pulse interval measuring means based on a detection result of the track flow detecting means.

[0027] The optical disc apparatus further includes focus control means for controlling the light beam so that the convergence state of the light beam on the information carrier becomes a predetermined convergence state. When the focus control is deviated or inoperative, the pulse interval measuring means may be deactivated.

An optical disc device according to the present invention is characterized in that a data portion, which is an information track formed by an uneven guide groove capable of recording and reproducing other information, and a data portion formed at a predetermined distance from the center of the information track. Light amount detecting means for irradiating a light beam onto an information carrier having an address portion in which address information corresponding to an information track is recorded in one or more uneven pits to detect information recorded on the information track; Address part detection means for detecting that the light beam is on the address part based on the output of the light quantity detection means, and pulse number measurement means for counting the signals output by the address part detection means within a fixed time A radial position estimating means for estimating a radial position of the light beam with respect to the information carrier based on an output of the pulse number measuring means; To operate the radial position estimating means when the distribution is no longer be read, based on the estimated radial position, and a clock setting means for setting a reproduction clock, the objects can be achieved.

[0029] The optical disk apparatus further includes a track shift detecting means for detecting a track shift amount of the light beam when passing through the address section, and the address section detecting means outputs two outputs of the track shift detecting means. Including a binarizing means for binarizing, the pulse number measuring means counts the number of binarized pulses output by the binarizing means,
The radial position estimating means may estimate a radial position of the light beam based on a time during which the information carrier makes one rotation and an output of the pulse number counting means.

[0030] The optical disc device includes a focus control unit that keeps the convergence state of the light beam on the information carrier constant, and a control state determination unit that determines that the focus control unit is operating normally. Furthermore, the optical disk device may not use the output of the pulse number measuring means based on the determination result of the control state determining means.

[0031] The light quantity detecting means may detect the information recorded on the information track based on the light beam reflected on the information carrier.

[0032] The light amount detecting means may detect the information recorded on the information track based on the light beam transmitted through the information carrier.

According to one aspect of the present invention, a light beam is convergently radiated onto an optical disk, and reflected light and transmitted light from the optical disk are detected.
The tracking control is operated, and address information is acquired by a signal processing device such as a digital processor using the address polarity determination signal. Further, when even one piece of address information can be obtained, the address is determined using the address polarity determination signal, and the information on the optical disk is reproduced and recorded.

According to another aspect of the present invention, a light beam is convergently irradiated on the information carrier, and light reflected on the information carrier or light transmitted through the information carrier is detected. Detects the address part recorded in
With a signal processing device such as a digital signal processor,
Estimate the radial position of the light beam on the information carrier by measuring the detection signal such as the track shift signal and the interval of the address part, and set the parameters such as the reproduction clock according to the estimated radial position. By doing so, the information on the information carrier is reproduced and recorded.

According to still another aspect of the present invention, a light beam is convergently irradiated on an information carrier, and light reflected on the information carrier or transmitted through the information carrier is detected. The address part recorded above is detected, and further, a detection signal such as a track shift signal is measured by a signal processing device such as a digital signal processor, and the number of address parts through which the light beam passes within a predetermined time is further measured. By counting, the radial position of the light beam on the information carrier is estimated, and by setting parameters according to the estimated radial position, the information on the information carrier is reproduced and recorded.

[0036]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the drawings, members having the same functions are denoted by the same reference numerals.

(Embodiment 1) FIG. 1 shows a block diagram of an optical disk apparatus 100 on which a semiconductor laser light source 10, which is one of the light sources, is mounted to reproduce and record a recordable optical disk.

As shown in the figure, the optical disc apparatus 100 of the present invention includes a light beam 1 on an optical disc 12 as an information carrier.
The semiconductor laser 10 includes a semiconductor laser light source 10 for irradiating the semiconductor laser 9, a coupling lens 15 for collimating light emitted from the semiconductor laser 10, a converging lens 16, and an actuator 17. Further, the optical head 11 includes the quadrant photodetector 14.

The light beam emitted from the semiconductor laser light source 10 is collimated by the coupling lens 15.
The parallel light then passes through a polarizing beam splitter 18 and is converged by an actuator 17 by a focusing lens 16 that moves in the focusing and tracking directions, thereby forming a light beam spot on the disk 12.

The optical disk device 100 includes a four-divided photodetector 14 as an element for receiving the reflected light from the disk 12. Light reflected from the disk 12 is convergent lens 1
6. The light passes through the polarization beam splitter 18 and enters the four-division photodetector 14.

The quadrant photodetector 14 is divided into regions A to D as shown in FIG. A focus shift signal and a track shift signal are obtained based on the sum signal of the diagonal areas A to D.

As shown in FIGS. 1 and 2, the outputs of the current / voltage conversion amplifiers 21A and 21B are added by an adder 22C, and the outputs of the current / voltage conversion amplifiers 21C and 21D are added by an adder 22D. , The difference signal between the adders 22C and 22D is obtained by the differential amplifier 24 to obtain the track deviation signal TE.

As shown in FIG. 1, the focus shift signal F
E adds the outputs of the current-voltage conversion amplifiers 21A and 21C by an adder 22A, and outputs the output 21
The outputs of B and 21D are added by an adder 22B.
The difference signal between 2A and 22B is obtained by the differential amplifier 23.

The focus shift signal FE becomes a digital signal in the AD conversion circuit 25 and is input to a focus filter 29 constituted by a digital signal processor or the like. The focus control is realized by controlling the actuator 17 via the DA conversion circuit 30 based on the output of the focus filter 29.

The track shift signal TE passes through a low-pass filter (LPF) 26 to remove noise, and is converted into a digital signal by an AD conversion circuit 27. The tracking filter 28 is constituted by a digital signal processor or the like.
Is input to The tracking control is realized by controlling the actuator 17 via the DA conversion circuit 31 based on the output of the tracking filter 28.

The light amount detecting means comprises the optical head 11 and current / voltage conversion amplifiers 21A to 21D.

Next, the address reading method of the present invention,
2 and 3A, and the configuration of an apparatus for realizing it.
This will be described with reference to FIG. 3B.

FIG. 2 shows a detailed view of the four-divided photodetector 14, a mirror section 300, a pit section 301 and a data section 302, and a track shift signal 303 output when passing through the address section. The following shows the correspondence.

FIG. 3A is a block diagram of an address polarity judging circuit 61 for detecting an address polarity judging signal for reading an address.

The track shift signal TE obtained based on the signal detected by the quadrant photodetector 14 shown in FIG.
It passes through a high-pass filter composed of a capacitor 401 and a resistor 402. As shown in FIG.
The DC level of the track shift signal TE is converted so as to be symmetrical with respect to the center 11.

Comparators 403 and 406
Generates the address polarity determination signals 409 and 410 by binarizing the track shift signal TE and connecting the binarized pulse trains by the mono-multi 405 and the mono-multi 408, respectively.

By setting the threshold value 404 and the threshold value 407 to the positive side and the negative side of the reference voltage 411, the pit portion 301 of the address portion AD through which the light beam has passed can be tracked based on the track shift signal TE. It is possible to distinguish whether the center is on the outer peripheral side or the inner peripheral side.

The comparator 403 and the mono multi 40
5, an outer address polarity determining signal 409 is generated by the comparator 5, and an inner address polarity determining signal 410 is generated by the comparator 406 and the mono-multi 408. The present invention is not limited to this address polarity determination signal generation method.

The address reading circuit 52 reads address information recorded in the pit section 301 of the address section AD on the optical disk 12. For example, the address information is generated after performing signal processing such as binarizing a signal obtained when the light beam 19 passes through the pit section 301 and decoding a binarized pulse train. The specific processing method is not directly related to the present invention, and thus the description is omitted.

Hereinafter, the address section AD is defined as CAPA (CO
MPLEMENTARY ALLOCARDED PIT
ADDRESS). The description will be made using the outer-side address polarity determination signal CPDT1 and the inner-side address polarity determination signal CPDT2.

An address reading circuit 52 for reading the address information recorded in the pit section 301 acquires the address information based on the output of the differential amplifier 24. The address polarity determination circuit 51 generates an address polarity determination signal based on the output of the differential amplifier 24 with the above-described configuration.

The address information determination circuit 53 determines the address of the track on which the light beam is scanning based on the address polarity determination signals CPDT1 and CPDT2 and the output of the address information reading circuit 52.

However, if all the address information can be read, the address information determination circuit 53 determines whether the track currently scanned by the light beam is a land or a groove based on the read address information and the reading order. To identify.

FIG. 4A is a diagram showing the relationship between the address part and the data part on the optical disk. FIG. 4B is a diagram showing a relationship between an address polarity determination signal and an address portion and a data portion on the optical disc. With reference to FIGS. 4A and 4B, the relationship between the address polarity determination signal and the address portion and the data portion on the optical disc will be described.

As shown in FIG. 5, as described above, each land track 503 and groove track 504 are connected in a spiral on the optical disc 12, and an address is provided between each track 503 and groove track 504. An area AD is arranged. Address area AD
, The bit portion 501 and the mirror portions 502 are arranged in a staggered manner.

The boundary between the mirror portions 502 and the pit portions 501 arranged in a staggered manner is a tracking center,
The track address when the light beam scans from the land 505 to the land 506 is determined by the address information ADRA and the address information ADRB.

The address of the land 506 is the address information A
The determination can be made when the address information can be obtained in the order of DRA and the address information ADRB, and the address of the groove 508 can be determined when the address information can be obtained in the order of the address information ADRC and the address information ADRB.

Address information ADRA, address information AD
If both RBs can be obtained, the current position of the light beam can be determined. However, if only one of the address information ADRA and the address information ADRB can be obtained, the current position of the light beam cannot be specified.

That is, when the information recorded on the land 506 of the data portion or the information is to be recorded, the address information corresponding to the land 506 as the data portion is set as the address information ADRA. By obtaining both the address information of the ADRA and the address information ADRB, the position of the light beam is specified, and the reproduction or recording of the information on the optical disk becomes possible.

If dust or scratches are present on the optical disc, or lens shift occurs due to eccentricity or external impact, a situation occurs in which address information cannot be obtained.

In this embodiment, the light beam is applied to the land 50.
5, when scanning is performed in the order of address information ADRA, address information ADRB, and land 506, and when the light beam is irradiated with a groove 507, address information ADRC, and address information ADR.
The case of scanning with B, groove 508 will be described.

The light beam is transmitted from the land 505 to the land 506.
, It is assumed that the address information ADRA cannot be read and only the address information of the address information ADRB can be obtained. In addition, the light beam has a groove 507.
From the address information A when passing through the groove 508
Address information ADRB without being able to read DRC
It is assumed that only the address information has been obtained.

In such a case, it is not possible to distinguish whether the light beam is scanning the land 505 or the groove 507 by only the address information. This is because it cannot be determined whether the light beam has passed on the outer side of the address information ADRB or the light beam has passed on the inner side of the address information ADRB.

Therefore, in the present embodiment, reference is made to an address polarity determination signal output when a light beam passes through this address information ADRB.

The address information of the address information ADRB has been obtained, and the outer-side address polarity determination signal 515 has been obtained.
Is output, the light beam is scanning from the land 505 to the land 506.

On the other hand, assuming that the address information of the address information ADRB has been obtained and the inner-peripheral-side address polarity determination signal 516 has been output, the light beam is scanning the groove 507 through the groove 508.

That is, the address polarity determination signals 515, 5
By referring to No. 16, if at least one of the address information arranged in a staggered manner can be acquired, the address of the acquired address part can be determined.

Further, the address information reading circuit 52
When both of the address information arranged in a zigzag pattern can be obtained, the central processing unit (CPU) 54 or the like uses the output result of the address information determination circuit 53 as it is, and the address information reading circuit 52 When only one of the address information arranged in the shape can be obtained, C
The address information determination circuit 53 may be switched by the PU 54 or the like so as to refer to the address polarity determination signals 515 and 516. As described above, according to the present invention, even in a situation where only one piece of address information recorded in the address portion can be obtained, the track scanned by the light beam is determined by using the address polarity determination signal. , And enables the reproduction and recording of the recorded information.

(Embodiment 2) A second embodiment of the present invention will be described with reference to FIG. 5, FIG. 6, FIG. 7, and FIG.

FIG. 5 shows an optical disk device 20 according to this embodiment.
0 is a configuration block diagram. Since the focus control and the tracking control are the same as those in the first embodiment, the description is omitted.

FIG. 6 shows the correspondence between the arrangement of the address section and the track shift signal, the RF signal of the address section, and the address polarity determination signal.

Referring to FIG. 5, defocus signal FE
And the track shift signal TE is used as a control state determination circuit 9 for determining the current state of focus control and tracking control.
00 is input.

The control state determination circuit 900 determines that the focus shift signal FE has exceeded a predetermined output, and detects that the focus has been lost. Further, it is determined that the track deviation signal TE has exceeded a predetermined output or that the light beam has traversed a predetermined number of tracks or more, thereby detecting that the tracking control is unstable. In particular, a circuit for determining that a light beam has traversed a predetermined number of tracks or more is called a flow detection circuit, and is also used for tracking pull-in confirmation at the end of a seek.

Address section 100 recorded with uneven pits
As shown in FIG. 6, 1 is formed by a mirror portion 1003 and an uneven pit portion 1000. The light beam 19 is applied to a boundary line L between the mirror portion 1003 and the concave / convex pit portion 1000.
Scan along 6 along the track. At this time, the track shift signal TE is obtained as an output of the low-pass filter 26 in FIG. 5, and becomes an S-shaped upper side as shown in FIG.

The track shift signal TE output from the low-pass filter 26 passes through the AD conversion circuit 27, and the control state determination circuit 900, a maximum value measuring circuit for measuring the maximum value (VMAX) of the track shift signal TE within a certain time period 901,
A minimum value measuring circuit 903 for measuring a minimum value (VMIN) within a certain time, an average value measuring circuit 902 for measuring an average value (VAVE) of the track error signal TE within a certain time, and the tracking error signal TE at a predetermined level; Amplitude conversion circuit 904 for converting the signal into an absolute value signal,
Is input to each of the binarization circuits 907 for binarizing the data by the value set by the threshold value setting circuit 908.

Address portion detection circuit 906 includes a binarization circuit 907 and a threshold value setting circuit 908.

FIG. 7A shows a track shift signal TE, a maximum value 1101, an average value 1103, and a reference voltage (VREF) 1.
10 shows a correspondence relationship between an address portion 110, a minimum value 1104, and an address portion detection signal 1105 for identifying an address portion.

As shown in FIG. 7A, the track shift signal T
By binarizing E with a threshold value 1102, a pulse signal is obtained, and this pulse signal becomes an address portion detection signal 1105.

As shown in FIG. 7A, ideally,
The track deviation signal TE is output symmetrically about the predetermined reference voltage 1110 as a symmetry axis. Reference voltage 1 here
Numeral 110 corresponds to the target voltage for tracking control, which coincides with the average value (VAVE) 1103 of the track deviation signal TE.

The track shift signal TE includes a lens shift,
Due to the optical characteristics of the optical head and the like, there is a case where the output voltage is not asymmetrical with respect to the reference voltage 1110 as a symmetry axis but is asymmetrical. In such a case, the threshold value 1 of the binarization circuit 907 is used.
It is necessary to set 102 appropriately.

Therefore, a method of setting the threshold value 1102 using the maximum value 1101 and the minimum value 1104 of the track shift signal TE within a predetermined time will be described.

When the light beam is at the track center and there is no disturbance such as a lens shift, the threshold value 1102 can be set as follows so as to be less affected by the fluctuation of the track shift signal TE.

Referring to FIG. 7A, threshold value 1102 is
It can be set to be more positive than the reference voltage 1110 based on a predetermined ratio to the difference (VPD) 1107 between the maximum value 1101, the reference voltage 1110, and the maximum value 1101 and the reference voltage 1110. For example, when the predetermined ratio is m: n, the threshold value 1102 is set by the following (Equation 1).

Threshold value 1102 = ((m × maximum value 1101 + n × reference voltage 1110) / (m + n)) (Equation 1) Referring to FIG. 7B, threshold value 1102 is the maximum value 110
1, minimum value 1104, maximum value 1101, and minimum value 1104
And a predetermined ratio to the difference between. For example, when the predetermined ratio is m: n, the threshold value 1102 is set by the following (Equation 2).

Threshold value 1102 = ((m × maximum value 1101 + n × minimum value 1104) / (m + n)) (Equation 2) Referring to FIG. 7C, threshold value 1102 is equal to reference voltage 1
110, minimum value 1104, reference voltage 1110, and minimum value 1
Based on the predetermined ratio to the difference (VMD) between the reference voltage 1110 and the reference voltage 1110, the reference voltage 1110 may be set to be more negative. For example, when the predetermined ratio is m: n, the threshold value 1102 is set by the following (Equation 3).

Threshold value 1102 = ((m × reference voltage 1110 + n × minimum value 1104) / (m + n)) (Equation 3) Whether the threshold value is set on the positive side of reference voltage 1110,
Whether the threshold value is set on the negative side depends on the difference (VPD) 1107 between the maximum value 1101 and the average value 1103 and the minimum value 1101.
The determination is made based on the difference (VMD) 1108 between 4 and the reference voltage 1110.

From the difference (VMD) 1108, the difference (VPD) 1
If 107 is large, the threshold value 1102 is set to the positive side, and if the difference (VMD) 1108 is smaller than the difference (VPD) 1107, the threshold value 1102 is set to the negative side. In addition, it is possible to detect the address portion.

When the maximum value 1101, the minimum value 1104, and the average value 1103 of the track deviation signal TE within a predetermined time are used, the average value 1103 is used instead of the above-described reference voltage 1110. The setting of the threshold value 1102 can be performed.

That is, the threshold value 1102 is set to the reference voltage 1
Whether the value is more positive than 110 or negative is determined by the maximum value of 11
01 and the average value 1103 (VPD) 1107 and the difference (VMD) 1108 between the minimum value 1104 and the average value 1103.
To judge. Difference (VPD) 1 from difference (VMD) 1108
If 107 is large, the threshold value 1102 is set to the positive side, and if the difference (VMD) 1108 is smaller than the difference (VPD) 1107, the threshold value 1102 is set to the negative side. In addition, it is possible to detect the address portion.

A threshold value setting method using the amplitude absolute value conversion circuit 904 (FIG. 5) will be described with reference to FIGS. 8A and 8B. As shown in FIG. 8A, when the track deviation signal TE fluctuates due to the eccentricity of the optical disk or the like, the accuracy of the measurement of the maximum value and the minimum value decreases, and even if the threshold value 1102 (FIG. 7) is set, the address portion is not changed. It may not be detected.

Therefore, as shown in FIG.
The signal is converted by taking the absolute value of the amplitude of the track deviation signal TE with 203 as the axis of symmetry.

After the amplitude absolute value conversion, FIGS. 7A to 7C
As described above with reference to, by setting the threshold 1200, the address portion can be detected.

Further, after the amplitude absolute value conversion, the maximum value 1202 of the track deviation signal TE is measured, and the threshold value 1200 is calculated.
May be set. Based on the threshold value set in this way, the binarizing circuit 907 outputs a pulse-like address portion detection signal 1105.

The address portion detection signal 1105 is input to a pulse interval measuring circuit 909 for measuring a pulse interval, and a time interval between the input pulses is measured to obtain an address interval as shown in FIG. Information (CPT
IME) 1106 can be obtained. When the address interval information 1106 has been obtained, the address interval measurement ends.

Next, the address interval information 1106 is input to a radial position estimating circuit 910 for estimating the radial position of the light beam 19 with respect to the optical disk 12.

The radius position estimating circuit 910 has a regular pulse corresponding to the number of rotations from the spindle motor, for example,
Several pulses (FG) for controlling the frequency of the motor are input from the one rotation time measurement circuit 905, and the time of one rotation of the disk can be known based on the pulses.

When the address portion and the data portion are formed on the optical disc 12 in a manner that the address portion and the data portion are separated by a zone in the radial direction, the address portion recorded at a constant interval in one track around the track for each zone. The numbers are different. Further, since there is almost no rotation unevenness during one rotation of the optical disk 12, there is almost no time variation of one rotation of the disk.
Further, at the radial position of the track on which the light beam is scanning, the passing address portions are also arranged at regular intervals.
When the optical disk 12 is rotating at a constant linear velocity,
Depending on the radial position of the track that the light beam is scanning,
The interval of the address part differs.

Therefore, it is possible to estimate the current radial position of the light beam from the interval between the pulses detected in the address section and the rotation time of the optical disk.

The radial position information estimated by the radial position estimating circuit 910 is input to a clock generating circuit 911 that generates a reference signal according to the linear velocity. The clock generation circuit 911 outputs a reference clock corresponding to the linear velocity, sets a target rotation speed of the motor, and corrects a predetermined PLL pull-in range linear velocity. Therefore, the PLL can be pulled in and the address can be read.

As described above, in the normal state, the radial position can be estimated based on the pulse output from the address section, and the clock can be set according to the radial position of the track on which the light beam is scanning. If the focus is deviated due to the application of a shock from the inside or from the outside, the address cannot be read. Therefore, the clock must be reset and the PLL must be pulled in again to read the address.

Clock setting from this address interval measurement,
The pull-in of the PLL will be described.

In the address interval measurement, the track shift signal T
Since E is used, it operates even if the clock is not set to one corresponding to the linear velocity. If the tracking control or the focus control is unstable, a malfunction occurs.

In a state where the address cannot be read, first,
When both the focus control and the tracking control are stable, the operation of the address interval measurement is started, the maximum value, the minimum value, and the average value of the track deviation signal TE are measured, and a threshold value is set based on the information, The track shift signal is binarized, the pulse interval is measured based on the output pulse, the radial position is estimated based on the pulse interval, and an appropriate clock is set.

When the tracking control is unstable, when the address interval is measured, the track shift signal fluctuates drastically, so that incorrect address interval information is obtained.

Therefore, the address interval measurement operation is not started, or the maximum value of the track shift signal is
If tracking control becomes unstable during measurement of the minimum value and the average value, erroneous setting can be avoided by not using the obtained address interval information.

Similarly, if the focus control is unstable, incorrect address interval information will be obtained.
Therefore, if the address interval measurement operation is not started, or if the focus control becomes unstable during measurement of the maximum value, minimum value, and average value of the track shift signal, the obtained address interval information is used. By not doing so, incorrect settings can be avoided.

In this way, the address interval measurement can be performed more accurately, and the radial position of the track on which the light beam is scanned can be more accurately estimated, and the optimum reference clock can be output. By setting the target number of revolutions, the PLL is pulled in again, and reproduction and recording of information on the optical disk are realized.

(Embodiment 3) Embodiment 3 of the present invention will be described with reference to FIGS.

In FIG. 9, since the tracking control and the focus control are the same as those in the first embodiment, those having the same functions are denoted by the same reference numerals and description thereof is omitted.

The track deviation signal TE, the maximum value measurement circuit 901, the minimum value measurement circuit 903, and the average value measurement circuit 9
02, the generation of the address part detection signal using the amplitude absolute value conversion circuit 904 is common to the second embodiment, and thus the description is omitted.

As shown in FIG. 9, the focus shift signal F
E and the track deviation signal TE are input to a control state determination circuit 900 that determines the current state of focus control and tracking control.

The output pulse of the address part detection circuit 906 is input to a pulse number measurement circuit 1300 that counts the number of pulses input within a predetermined time.

The output of the pulse number measuring circuit 1300 is input as address number information to a radial position estimating circuit 910 for estimating the radial position of the light beam 19 with respect to the optical disk. The radius position estimating circuit 910 includes a regular pulse corresponding to the number of rotations from the spindle motor 13, for example,
Several pulses (FG) for controlling the frequency of the motor are input via the one-rotation time measurement circuit 905, and the time of one rotation of the disk can be known based on the pulses.

When the address portion and the data portion are separated by zones in the radial direction on the optical disc 12, the number of address portions recorded at regular intervals in one round of the track differs for each zone. Further, there is almost no variation in the time of one rotation of the optical disk 12.

Therefore, the number of addresses during one rotation of the disk differs depending on the radial position of the track scanned by the light beam 19.

Therefore, it is possible to estimate the radial position of the track currently being scanned by the light beam from the number of pulses detected in the address section during one rotation of the optical disk and the rotation time of the optical disk. Becomes

In order to detect one rotation of the optical disk, one rotation information can be obtained from the pattern of the track shift signal TE in addition to the method of measuring the output pulse from the spindle motor 13 as described above. A method for obtaining one rotation information of the optical disk by using the track shift signal TE will be described with reference to FIG.

As described in the first embodiment, when the address section and the data section are separated on the optical disc 12 and the address sections are recorded in a staggered manner, the light beam 19 may be tracked on the track. Then, it passes through the land / groove switching unit every other rotation.

From this, when the polarity of the track shift signal output when passing through the address portion recorded in a staggered manner or when the order of the address polarity determination signal is inverted, the starting point of one rotation is determined. For example, one rotation of the optical disk can be detected.

In FIG. 10, for example, assuming that the light beam 19 scans over the land, the address units 1404, 1404
In 405 and 1406, the address polarity determination signals are the address polarity determination signal 1402 and the address polarity determination signal 140.
3 are output in order.

On the other hand, the address portions 1407 and 1408 output the address polarity determination signal 1403 and the address polarity determination signal 1402 in the reverse order.
Is scanning the groove area.

Therefore, the address polarity determination signal 1402,
Using the information that the order of 1403 is reversed, one rotation information of the optical disc 12 can be obtained, and the radial position can be estimated.

The radial position information estimated by the radial position estimating circuit 910 is input to a clock setting circuit 911 for generating a reference signal corresponding to the linear velocity.
Reference numeral 11 outputs a reference clock corresponding to the linear velocity, sets the target rotation speed of the motor 13, and corrects the linear velocity within a predetermined PLL pull-in range, thereby pulling in the PLL and reading the address.

As described above, in the normal state, the radial position can be estimated based on the pulse output from the address section, and the clock can be set according to the radial position of the track on which the light beam is scanning. If the focus is deviated due to a middle or external impact, the address cannot be read. Therefore, the clock must be reset and the PLL must be pulled in again to read the address.

Measurement of number of addresses, clock setting, PL
The L pull-in will be described.

Since the measurement of the number of addresses uses the track shift signal TE, the operation is performed even if the clock is not set to one corresponding to the linear velocity. If the tracking control or the focus control is unstable, a malfunction occurs.

In a state where the address cannot be read, first,
When both the focus control and the tracking control are stable, the operation of counting the number of addresses is started, the maximum value, the minimum value, and the average value of the track deviation signal TE are measured, and a threshold value is set based on the information. The track shift signal is binarized, the number of pulses is measured based on the output pulses, the radial position is estimated based on the number of pulses, and an appropriate clock is set.

When the tracking control is unstable, if the address number interval is measured, the track deviation signal TE is disturbed, so that incorrect address number information is obtained.

Therefore, if the address count measurement operation is not started, or if the tracking control becomes unstable during the measurement of the maximum value, the minimum value, and the average value of the track deviation signal TE, the obtained address is obtained. By not using the number information, erroneous setting can be avoided.

Similarly, if the focus control is unstable, incorrect address number information will be obtained.

Therefore, if the address count measurement operation is not started, or if the focus control becomes unstable during the measurement of the maximum value, the minimum value, and the average value of the track deviation signal TE, the obtained address is not obtained. By not using the number information, erroneous setting can be avoided.

In this way, the address number measurement can be performed more accurately, and the radial position of the track on which the light beam is scanned can be more accurately estimated, and the optimum reference clock can be output, By setting the target number of revolutions, the PLL is pulled in again, and reproduction and recording of information on the optical disk are realized.

[0138]

As described above, according to the present invention, even when only one piece of address information recorded in the address portion can be obtained, the light beam can be scanned by using the address polarity determination signal. Track can be determined. Also, based on the detection signal of the address section,
By measuring the address interval, it is possible to estimate the radial position where the light beam is scanning, output a reference clock, and acquire address information. Further, by measuring the number of addresses based on the address part detection signal, it is possible to estimate the radial position where the light beam is scanning, output a reference clock, and acquire address information. As described above, the present invention realizes reproduction and recording of information on an optical disk, and makes it possible to provide an inexpensive and highly reliable optical disk device.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a configuration of an optical disc device according to a first embodiment.

FIG. 2 is a block diagram showing details of a photodetector in the optical disk device according to the first embodiment;

FIG. 3A is a configuration block diagram of an address polarity determination circuit according to the first embodiment;

FIG. 3B is an explanatory diagram of an address polarity determination signal according to the first embodiment.

FIG. 4A is a schematic diagram showing an arrangement of an address portion and a data portion on the information carrier according to the first embodiment.

FIG. 4B is a schematic diagram showing a relationship between an arrangement of an address portion and a data portion on the information carrier and an address polarity determination signal according to the first embodiment.

FIG. 5 is a block diagram for explaining a configuration of an optical disk device according to a second embodiment.

FIG. 6 is a schematic diagram showing a correspondence relationship between an address part and an address polarity determination signal.

FIG. 7A is a schematic diagram showing a correspondence relationship between a track shift signal and an address detection signal.

FIG. 7B is a schematic diagram showing the correspondence between a track shift signal and an address detection signal.

FIG. 7C is a schematic diagram showing the correspondence between a track shift signal and an address detection signal.

FIG. 8A is a waveform chart for explaining an amplitude absolute value conversion circuit.

FIG. 8B is a waveform chart for explaining the amplitude absolute value conversion circuit.

FIG. 9 is a block diagram illustrating a configuration of an optical disc device according to a third embodiment.

FIG. 10 is a waveform diagram of a track shift signal in a land / groove switching unit according to the third embodiment.

FIG. 11 is a schematic diagram showing an arrangement of an address portion and a track on an optical disc.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Semiconductor laser 12 Optical disk 13 Spindle motor 14 Photodetector 15 Coupling lens 16 Convergent lens 17 Actuator 18 Polarization beam splitter 19 Light beam 21A, 21B, 21C, 21D Current-voltage conversion amplifier 22A, 22B, 22C, 22D Adder 23 , 24 Differential amplifier 25, 27 AD conversion circuit 26 Low-pass filter 28 Tracking filter 29 Focus filter 30, 31 DA conversion circuit 51 Address polarity determination circuit 52 Address information reading circuit 53 Address information determination circuit 54 CPU

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naohiro Kimura 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (15)

[Claims] 1. A data section, which is an information track formed by an uneven guide groove capable of recording and reproducing information, and address information formed at a position at a predetermined distance from the center of the information track and corresponding to the information track. A light amount detecting means for irradiating a light beam onto an information carrier having an address portion recorded with one or more uneven pits to detect information recorded on the information track; and a signal output by the light amount detecting means. Based on whether the address portion through which the light beam has passed is on the outer peripheral side with respect to the center of the information track scanned by the light beam,
Address polarity determining means for determining whether the address is on the inner side, address information reading means for reading the address information recorded in the address section based on a signal output from the light amount detecting means, and address polarity determining means An optical disc device comprising: an address information determining unit that determines the data portion to be reproduced and recorded based on the determination result of the above and the address information read by the address reading unit. 2. The address section includes two or more address areas in which the address information is recorded, wherein the address areas are arranged in a staggered manner at a predetermined distance from a center of the information track. 2. The optical disc device according to claim 1, wherein the information tracks to be shared share the address area. 3. A data portion, which is an information track formed by an uneven guide groove capable of recording and reproducing information, and address information formed at a predetermined distance from the center of the information track and corresponding to the information track. A light amount detecting means for irradiating a light beam onto an information carrier having an address portion recorded with one or more uneven pits to detect information recorded on the information track, and based on an output of the light amount detecting means Address section detecting means for detecting that the light beam is on the address section; pulse interval measuring means for measuring an interval between the address sections based on an output of the address section detecting means; A radial position estimating means for estimating a radial position of the light beam based on a measurement result of the means; Zui and an optical disk apparatus and a clock generating means for generating a recovered clock. 4. The optical disk device further includes a track shift detecting unit that detects a track shift amount of the light beam when the light beam passes through the address unit, and the address unit detecting unit outputs an output of the track shift detecting unit. The pulse interval measuring means measures an interval of an output pulse of the binarizing means, and the radial position estimating means includes a time for the information carrier to make one rotation and the pulse. 4. The optical disk device according to claim 3, wherein a radial position of the light beam is estimated based on an output of the interval measuring means. 5. An optical disk device, comprising: a track shift detecting means for detecting a track shift amount of a light beam when passing through the address portion; and measuring a maximum value of an output signal of the track shift detecting means within a predetermined time. Further comprising: a maximum value measuring means for measuring the output signal of the track shift detecting means; and a minimum value measuring means for measuring a minimum value of the output signal of the track shift detecting means within a predetermined time. Binarizing means for binarizing, and for binarizing the output of the track deviation detecting means based on the maximum value outputted by the maximum value measuring means and the minimum value outputted by the minimum value measuring means. 5. The optical disk device according to claim 4, further comprising: threshold setting means for setting a threshold value. 6. The optical disk device, wherein: a track shift detecting means for detecting a track shift amount of a light beam when passing through the address portion; and measuring a maximum value of an output signal of the track shift detecting means within a predetermined time. A maximum value measuring means, a minimum value measuring means for measuring a minimum value of an output signal of the track deviation detecting means within a certain time, and an average for measuring an average value of the output signal of the track deviation detecting means within a certain time. Further comprising: a value measuring means, wherein the address portion detecting means includes: a binarizing means for binarizing an output of the track deviation detecting means; a maximum value outputted by the maximum value measuring means; and a measurement of the minimum value. A threshold for binarizing the output of the track deviation detecting means based on one of the minimum values outputted by the means and the output of the average value measuring means. And a threshold setting means for setting the optical disk apparatus according to claim 4, wherein. 7. The optical disk device, wherein: a track shift detecting means for detecting a track shift amount of a light beam when passing through the address portion; and measuring a maximum value of an output signal of the track shift detecting means within a predetermined time. Further comprising: a maximum value measuring means for calculating the absolute value of an output signal of the track shift detecting means; and an amplitude absolute value converting means for obtaining an absolute value of an amplitude of the output signal of the track shift detecting means. A threshold value for binarizing the output of the track deviation detecting means based on the maximum value output by the maximum value measuring means and the output of the average value measuring means. The optical disk device according to claim 4, further comprising a threshold value setting unit. 8. The output pulse output after the output pulse continuously output for a shorter time than a fixed period when the output pulse of the binarization means is measured. 5. The optical disk device according to claim 4, wherein the interval of the output pulse is measured by disabling the output pulse. 9. The optical disk device, wherein: tracking control means for controlling the light beam so that the light beam scans on the track on the information carrier; and the optical disk device is off the track on which the light beam scans. 4. The optical disk device according to claim 3, further comprising: a track flow detecting unit configured to detect that the pulse interval measuring unit is disabled based on a detection result of the track flow detecting unit. 10. The optical disk device further includes a focus control unit that controls the light beam so that a convergence state of the light beam on the information carrier becomes a predetermined convergence state. 4. The optical disk device according to claim 3, wherein when the focus control by the control unit is deviated or inoperative, the pulse interval measuring unit is deactivated. 11. A data portion, which is an information track formed by an uneven guide groove capable of recording and reproducing information, and address information formed at a position at a predetermined distance from the center of the information track and corresponding to the information track. A light amount detecting means for irradiating a light beam onto an information carrier having an address portion recorded with one or more uneven pits to detect information recorded on the information track, and based on an output of the light amount detecting means Address part detecting means for detecting that the light beam is on the address part; pulse number measuring means for counting a signal output by the address part detecting means within a predetermined time; and an output of the pulse number measuring means. A radial position estimating means for estimating a radial position of the light beam with respect to the information carrier based on the address information, and when the address information cannot be read. The radial position estimating means is operated, on the basis of the estimated radial position, the optical disk device and a clock setting means for setting a reproduction clock. 12. The optical disk device further comprises a track shift detecting means for detecting a track shift amount of the light beam when passing through the address section, wherein the address section detecting means includes an output of the track shift detecting means. The pulse number measuring means counts the number of the binarized pulses output by the binarizing means, and the radial position estimating means comprises: 12. The optical disk device according to claim 11, wherein a radial position of the light beam is estimated based on a time to be performed and an output of the pulse number counting unit. 13. The optical disc device, wherein: a focus control unit for maintaining a constant convergence state of the light beam on the information carrier; and a control state determination unit for determining that the focus control unit is operating normally. 12. The optical disk device according to claim 11, further comprising: the optical disk device not using an output of the pulse number measurement unit based on a determination result of the control state determination unit. 14. The optical disk device according to claim 1, wherein the light quantity detection unit detects the information recorded on the information track based on the light beam reflected on the information carrier. 15. The optical disc device according to claim 1, wherein the light quantity detection means detects the information recorded on the information track based on the light beam transmitted through the information carrier.