JP2003051124A - Optical disk reproduction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk reproduction apparatus which determines whether a sector is an unrecorded sector or not even when the reproduction speed of a sector in the inner peripheral side of an optical disk is different from that of a sector in the outer peripheral side of the optical disk. SOLUTION: The optical disk reproduction apparatus includes a sector detection section for detecting a sector, a sector reproduction time measuring section for measuring a reproduction time of the sector and outputting sector reproduction time data which represents the measured reproduction time of the sector, an unrecorded portion detection section for detecting an unrecorded portion which is a portion of the sector having no information recorded thereon, an unrecorded portion time measuring section for measuring a reproduction time of the unrecorded portion and outputting unrecorded time data which represents the measured reproduction time of the unrecorded portion, and a sector determination section for determining whether the sector is an unrecorded sector or not based on a relationship between the sector reproduction time data and the unrecorded time data, the unrecorded sector being a sector which is in an unrecorded state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc reproducing apparatus for an optical disc having a track including a plurality of sectors.

[0002]

2. Description of the Related Art FIG. 15 shows a conventional optical disc reproducing apparatus 1.
The structure of 100 is shown.

The optical disk reproducing apparatus 1100 includes an address section detecting section 1106, a wobble detecting section 1107, a wobble PLL circuit 1108, and a data PLL circuit 1112.
A gate signal generation unit 1113, a scratch / unrecorded portion detection unit 1115, an unrecorded sector determination unit 1118, and a system controller 1117.

The flaw / unrecorded portion detecting portion 1115 determines whether or not the flaw portion of the sector is reproduced, and outputs a flaw detection signal indicating the flaw portion of the sector.

The scratch / unrecorded portion detection unit 1115 determines whether or not the unrecorded portion of the sector is being reproduced, and outputs an unrecorded portion detection signal indicating the unrecorded portion of the sector.

FIG. 16 shows the unrecorded sector discriminator 1118.

The unrecorded sector discrimination section 1118 includes an unrecorded time measuring section 2402 and a comparator 2405.

The unrecorded portion detection signal output from the scratch / unrecorded portion detection unit 1115 is input to the unrecorded time measuring unit 2402.

The unrecorded time measuring section 2402 measures the reproduction time of the unrecorded section of the sector and outputs unrecorded time data indicating the measured reproduction time of the unrecorded section.

A reference value (unrecorded sector detection level) is preset in the comparator 2405.

A comparator 2405 compares the unrecorded time data output from the unrecorded time measuring section 2402 with a reference value (unrecorded sector detection level). The comparator 2405 outputs an unrecorded sector determination signal that determines whether or not the sector is an unrecorded sector.

As described above, the optical disk reproducing apparatus 1100
Determines whether or not the sector is an unrecorded sector based only on the unrecorded time data.

FIG. 17 shows the Webbull PLL circuit 1108.

The wobble PLL circuit 1108 includes a phase comparator 1501, a switch 1502, and a phase compensator 150.
3, a variable oscillator 1504, and a division period 1505.

The phase comparator 1501 compares the wobble clock signal divided by the frequency divider 1505 with the phase of the wobble signal. The output from the phase comparator 1501 passes through the switch 1502 and the phase compensator 1503 so that the wobble clock signal is synchronized with the wobble signal.
504 is input.

The wobble PLL circuit 1108 inputs the address part detection signal output from the address part detection part 1106. Switch 150 according to the address detection signal
2 is turned off and the wobble PLL circuit 1108 is held while the address part is detected.

Further, the system controller 1117 is
If the address part detection signal cannot be detected a predetermined number of times, it is determined that the frequency of the data read clock signal is abnormal.

As described above, the optical disk reproducing apparatus 1100
Detects an abnormality in the frequency of the data read clock signal based on the address detection signal.

[0019]

When reproducing an unrecorded optical disk shipped without recording predetermined data in the data section when manufacturing the optical disk, and when a reproduction request for an unrecorded sector is received, It is necessary to detect that the reproduced sector is unrecorded and perform a stable reproducing operation.

However, since the conventional optical disk reproducing apparatus determines whether or not the sector is an unrecorded sector based only on the unrecorded time data, the reproduction speed of the sector on the inner circumference side of the optical disk and the optical disk When the reproduction speed of the sector on the outer peripheral side is different (for example, in the case of CAV reproduction), there is a problem that it cannot be determined whether or not the sector is an unrecorded sector. This is because the unrecorded time data depends on the reproduction speed of the sector.
Also, in the case of CLV reproduction, CLV control may not be accurately performed immediately after a seek, and the reproduction speed of the sector may differ for each sector. Also in this case, there is a problem that it is not possible to determine whether or not the sector is an unrecorded sector.
This is because the unrecorded time data depends on the reproduction speed of the sector.

Further, in the conventional optical disk reproducing apparatus, since the wobble PLL circuit is held only during the period when the address portion is detected, there is a problem that the address portion cannot be accurately detected based on the wobble clock signal. This is because there is a period in which the wobble clock signal is disturbed in the predetermined period in which the address part is not detected. The wobble clock signal is disturbed because the address portion cannot be accurately detected.

Further, since the conventional optical disk reproducing apparatus detects an abnormality in the frequency of the data read clock signal based on only the address detection signal, there is a problem that the abnormality in the frequency of the data read clock signal cannot be detected at high speed. there were. This is because it is necessary to count the number of times the address part detection signal is not detected.

FIG. 18 is a diagram for explaining the disturbance of the wobble clock signal.

FIG. 18A shows an address portion detection signal.

FIG. 18B shows a wobble signal.

In general, when the optical disk reproducing apparatus 1100 is operated, the period 2001 is delayed because the timing at which the address detecting unit 1106 detects the address is delayed.
During this period, the wobble PLL circuit 1108 operates and the wobble clock signal is disturbed. Also, the wobble detection unit 1107
The wobble signal is disturbed during the period 2002 due to the delay in the response timing of the band-pass filter of, and the wobble clock signal is disturbed accordingly.

The present invention has been made in view of the above problems. Even when the reproduction speed of the sector on the inner circumference side of the optical disc and the reproduction speed of the sector on the outer circumference side of the optical disc are different from each other, the sector is not yet recorded. An object of the present invention is to provide an optical disc reproducing apparatus capable of discriminating whether or not it is a recording sector.

Another object of the present invention is to provide an optical disk reproducing apparatus capable of accurately detecting an address portion based on a wobble clock signal.

It is another object of the present invention to provide an optical disk reproducing apparatus capable of detecting abnormalities in the frequency of the data read clock signal at high speed.

[0030]

An optical disk reproducing apparatus of the present invention comprises a sector detecting section for detecting a sector, a reproducing time of the sector, and sector reproducing time data indicating the measured reproducing time of the sector. The sector reproduction time measuring section for outputting, the unrecorded section detecting section for detecting an unrecorded section which is a section in which information is not recorded in the sector, and the reproduction time of the unrecorded section are measured and measured. Based on the relationship between the sector reproduction time data and the unrecorded time data and the unrecorded time measurement unit that outputs unrecorded time data indicating the reproduction time of the unrecorded area, the sector is in the unrecorded state. And a sector discriminating unit which discriminates whether or not the sector is an unrecorded sector as shown in the above.

The sector discriminating section may discriminate whether or not the sector is the unrecorded sector based on the difference between the sector reproduction time data and the unrecorded time data.

The sector discriminating section may discriminate whether or not the sector is the unrecorded sector based on the ratio between the sector reproduction time data and the unrecorded time data.

The optical disk reproducing apparatus further includes a scratch detecting section for detecting a scratch which is a scratch generated on the sector among the sectors, and the scratch detecting section detects the scratch, The unrecorded time measuring unit may stop the measurement.

The optical disk reproducing apparatus further includes a scratch detection unit for detecting a scratch that is a scratch generated on the sector among the sectors, and a period during which the scratch detection unit detects the scratch, The unrecorded time measurement unit may stop outputting the unrecorded time data.

The sector detecting section further includes an address section detecting section for detecting an address section, and during the period when the address section is detected by the address section detecting section, the sector reproducing time measuring section outputs the sector reproducing time data. May be stopped.

The optical disk reproducing apparatus is an optical disk reproducing apparatus for an optical disk having a track including a plurality of sectors, wherein the track is formed to wobble at a predetermined cycle, and the track of the plurality of sectors is formed. Each has an address section and a data section, and the optical disk reproducing apparatus includes a wobble detection section for detecting the wobble of the track, and a PLL section for outputting a clock signal synchronized with the cycle of the detected wobble. , And an address section detecting section for detecting the address section based on the clock signal.

The optical disk reproducing apparatus further includes a counter having a count value determined based on the number of times the clock signal is output, and the counter has the count value of the counter as the sector reproduction time data. The count value may be set to a predetermined value when the corresponding value is reached.

The optical disk reproducing apparatus of the present invention is an optical disk reproducing apparatus for an optical disk having a track including a plurality of sectors, wherein the track is formed to wobble at a predetermined cycle, and the plurality of tracks are formed. Each of the sectors has an address part and a data part, and the optical disk reproducing device outputs a wobble detecting part for detecting the wobble of the track and a PLL for outputting a clock signal in synchronization with the detected wobble period. Section, an address section detection section that detects the address section based on the clock signal, and a PLL hold section that holds the PLL section for a predetermined period including the period in which the address section is detected. The above object is achieved.

The address section detecting section detects the first address section and the second address section, and after a lapse of a first predetermined period from the time when the first address section is detected, the PLL hold section is After the hold of the PLL section is started and after the second predetermined period has elapsed since the detection of the second address section, the PL section is
The L hold unit may stop the hold of the PLL unit.

The first predetermined period may be a period which does not depend on the reproduction speed of the sector.

The second predetermined period may be a period which does not depend on the reproduction speed of the sector.

The first predetermined period may be a period determined based on the number of times the clock signal is output.

The second predetermined period may be a period determined based on the number of times the clock signal is output.

The optical disk reproducing apparatus further includes a counter having a count value determined based on the number of times the clock signal is output, and the second predetermined period is from the time when the second address section is detected. It may be a period until the count value of the counter reaches or exceeds a predetermined value.

The optical disk reproducing apparatus of the present invention is an optical disk reproducing apparatus for an optical disk having a track including a plurality of sectors, wherein the track is formed to wobble at a predetermined cycle, and the plurality of tracks are formed. Each of the sectors has an address section and a data section, and the optical disk reproducing apparatus includes a sector detection section for detecting the sector and a first PLL section for outputting a first clock signal synchronized with the detection cycle of the sector. A wobble detection unit that detects the wobble of the track, and a second P that outputs a second clock signal that is synchronized with the detected wobble cycle.
An LL unit, the first clock signal output from the first PLL unit, and the second clock signal output from the second PLL unit.
An abnormality detection device for detecting an abnormality in the frequency of the first clock signal based on the relationship with the clock signal, thereby achieving the above object.

The abnormality detecting device is configured to detect the frequency of the first clock signal based on the difference between the first clock signal output from the first PLL section and the second clock signal output from the second PLL section. May be detected.

The abnormality detecting device is arranged such that the frequency of the first clock signal is based on a ratio between the first clock signal output from the first PLL section and the second clock signal output from the second PLL section. May be detected.

[0048]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows zones and sectors included in the optical disk 1101.

FIG. 1A shows the structure of the optical disk 1101.

The optical disk 1101 is the optical disk 110.
It is divided into a plurality of zones (for example, the zone 902 and the zone 903) along one radial direction. In each zone, the recording linear density of tracks located at the same distance from the center of the optical disk 1101 is constant. In the same zone, the recording linear density is lower toward the outer track.

FIG. 1B shows the relationship between zones and sectors.

The zone includes a plurality of sectors. For example,
Zone 903 includes sector 905 and sector 906.

FIG. 2 shows a sector 905 included in the zone 903.
Indicates. In FIG. 2, an arrow M indicates the radial direction of the optical disc 1101.

The zone 903 is a land track 1 having a convex shape.
001 and a concave groove track 1002. The sector 905 has a data part 1003 and an address part 1005.
Including and The sector 905 includes a data part 1004 and an address part 1006. The address part is arranged at the head of the sector. The address portion 1005 and the address portion 1006 are arranged in sectors so that they can be read by both the light for scanning the land track and the light for scanning the groove track, and are shifted by a half track in the radial direction of the optical disk 1101. Has been done.

Data portion 100 of land track 1001
3 and the data portion 1004 of the groove track 1002
Are wobbled in the track direction. The wobble cycle of the track has a cycle of several hundred times that of the data read clock signal.

1. Configuration of the optical disc reproducing apparatus of the present invention FIG. 3 shows the configuration of the optical disc reproducing apparatus 100 of the present invention. The optical disc reproducing apparatus 100 is used for reproducing information on the optical disc 1101 shown in FIG.

The optical disk reproducing apparatus 100 includes a head unit 102 and a photodetector 103 attached to the head unit 102.

The head unit 102 irradiates the optical disc 1101 with a light beam. The position of the head unit 102 and the position of a converging lens (not shown) attached to the head unit 102 are controlled so that the converging point of the light beam is located on the recording surface of the optical disc 1101 and on the track center.

The photodetector 103 detects reflected light or transmitted light of the light beam. The photodetector 103 converts the detected light into an electric signal and outputs the electric signal to the subtractor 105.

The optical disc reproducing apparatus 100 includes an adder 10
4, a subtractor 105, an address section detecting section 106 for detecting an address section, a wobble detecting section 107 for detecting a wobble of a track, and a clock signal synchronized with a wobble cycle detected by the wobble detecting section 107. A wobble PLL circuit 108, a selector 109,
A selector 110, an equalizer section 111, a data PLL circuit 112 that outputs a clock signal synchronized with a detection cycle of a sector of the optical disk 1101, a gate signal generation section 113, an address read section 116, and a scratch / unrecorded section detection section. 115, an unrecorded sector determination unit 118, and a system controller 117 are further included. Selector 109
Selects either the signal output from the adder 104 or the subtractor 105 based on the signal output from the system controller 117. The selected signal is output to the selector 110.

FIG. 4 shows the configuration of the address part detection part 106.

The address section detecting section 106 includes a low pass filter 1201, a comparator 1202, a comparator 1203 and an OR element 1204. The electric signal output from the subtractor 105 is the address detection unit 1
It is input to the low pass filter 1201 included in 06.

The low-pass filter 1201 blocks the output of signals of the RF component band or higher in the band of the input electric signal.

The comparator 1202 detects a signal having an address part detection level 1 or higher among the output signals of the low pass filter 1201.

The comparator 1203 detects a signal of the output level of the low pass filter 1201 which is equal to or lower than the address detection level 2.

The logical sum calculation element 1204 calculates the logical sum of the signal detected by the comparator 1202 and the signal detected by the comparator 1203 to generate an address part detection signal.

The address section detecting section 106 detects the address section and outputs an address section detection signal.

The address detection unit 106 can detect the sector by detecting the address. A sector consists of an address part and a data part following the address part,
This is because detecting the address portion assigned to the beginning of the sector also means detecting the sector. Therefore, the address detection unit detects the sector. The address detection unit also functions as a sector detection unit in the present invention.

Referring again to FIG. 3, the description of the optical disc reproducing apparatus 100 of the present invention will be continued.

The electric signal output from the subtractor 105 is
It is also input to the wobble detection unit 107.

The wobble detector 107 inputs this input signal to the band pass filter. The bandpass filter outputs a wobble detection signal. Further, the wobble detection unit 107 binarizes this wobble detection signal and outputs a wobble signal.

FIG. 5 shows the waveforms of the input signals to the address section detecting unit 106 and the wobble detecting section 107 and the waveforms of the output signals from the address section detecting unit 106 and the wobble detecting section 107.

FIG. 5A shows an address part and a data part included in the sector.

FIG. 5B shows the electric signal (difference signal) output from the subtractor 105.

FIG. 5C shows a low pass filter 1201.
The signal output from is shown.

FIG. 5D shows the address part detection signal output from the logical sum operation element 1204.

FIG. 5E shows the wobble detection signal output from the bandpass filter.

FIG. 5 (f) shows a wobble signal obtained by binarizing the wobble detection signal.

Referring back to FIG. 3, the description of the optical disk reproducing apparatus 100 of the present invention will be continued.

The wobble PLL circuit 108 PLL-controls the wobble signal and outputs a wobble clock signal synchronized with the wobble cycle.

Details of the wobble PLL circuit 108 are as follows.
( 3. Hold of wobble PLL circuit ) will be described later.

The signal output from the address section detection section 106 is passed through the gate signal generation section 113 to the selector 110.
And the data PLL circuit 112. The selector 110 outputs the signal (address reproduction signal) selected by the selector 110 based on this signal. Selector 1
The output from 10 is input to the equalizer unit 111.
The equalizer unit 111 amplifies, limits, and binarizes a predetermined frequency band. The equalizer unit 111 outputs a reproduction RF signal. The reproduction RF signal is the data PLL circuit 11
Entered in 2. The data PLL circuit 112 generates a data read clock signal that serves as a reference when reproducing the information recorded on the optical disk 1101. Data PLL
The circuit 112 outputs a data read clock signal synchronized with the reproduction RF signal.

FIG. 6 shows the configuration of the data PLL circuit 112.

The data PLL circuit 112 includes the phase comparator 1
401, a switch 1402, and a phase compensator 1403
, Variable oscillator 1404, frequency divider 1405, selector 1406, period measuring instrument 1407, period measuring instrument 14
08, an amplifier 1409, a comparator 1410, and an OR operator 1411. The switch 1402 is opened / closed based on a signal from the system controller 117 (FIG. 3) to connect the selector 1406 to the comparator 1410 or the phase comparator 1401.

The wobble signal output from the wobble detector 107 is input to the period measuring device 1407 included in the data PLL circuit 112. The cycle measuring device 1407 measures the cycle of the wobble signal and outputs the measured value. Amplifier 14
09 amplifies this measurement. The comparator 1410 compares the amplified measured value with the measured value output from the period measuring device 1408, and outputs a control signal.

The control signal output from the comparator 1410 passes through the selector 1406 and the phase compensator 1403,
It is input to the variable oscillator 1404. Variable oscillator 1404
Outputs a data read clock signal.

In the division cycle 1405, the data read clock signal is divided and the divided signal is input to the cycle measuring device 1408.

By controlling the cycle of the wobble signal and the cycle of the data read clock signal in this manner, the data P
The LL circuit 112 keeps the ratio of the cycle of the wobble signal and the cycle of the data read clock signal constant.

When the optical disk reproducing apparatus 100 starts reproducing the address part and the data part, the system controller 117 causes the phase comparator 1401 to divide the frequency of the data read clock signal and the phase of the reproduction RF signal. The selector 1406 is switched so as to compare and.

The logical sum of the address section gate signal, which is a signal indicating the address section of the sector currently being reproduced, and the data section gate signal, which is a signal indicating the data section, is calculated as the logical sum operator 14
11 operates to input the output of the logical sum operator 1411 to the switch 1402, whereby the data PLL circuit 11
2 performs phase comparison in the data part and address part of the sector.

The output of the phase comparator 1401 is the switch 1
It is input to the variable oscillator 1404 through the selector 402, the selector 1406, and the phase compensator 1403.

By the control of the data PLL circuit 112,
The data read clock signal is synchronized with the reproduction RF signal.

The data PLL circuit 112 functions as the first PLL section in the present invention.

Referring back to FIG. 3, the description of the optical disk reproducing apparatus 100 of the present invention will be continued.

The gate signal generation unit 113 uses the wobble PL
A gate signal to be output to the L circuit 108 is generated.

For details of the gate signal generator 113, refer to ( 3.
Hold of the wobble PLL circuit ) will be described later.

2. Discrimination of Unrecorded Sector With reference to FIG. 3 again, the optical disc reproducing apparatus 10 of the present invention
The explanation of 0 is continued.

The optical disc reproducing apparatus 100 further includes a scratch / unrecorded portion detection unit 115 and an unrecorded sector determination unit 118.

FIG. 7 shows the structure of the flaw / unrecorded portion detection unit 115.

The flaw / unrecorded portion detecting portion 115 includes a low-frequency blocking filter 201, an envelope detecting circuit 202, a comparator 203, and a comparator 204.

The electric signal output from the adder 104 is
After being input to the low-pass blocking filter 201, it is input to the envelope detection circuit 202. Envelope detection circuit 2
02 detects the envelope signal of the signal output from the low-pass blocking filter 201. Envelope detection circuit 2
The envelope signal output from 02 is input to the comparator 203 and the comparator 204.

A reference value (scratch detection level) is preset in the comparator 203.

The comparator 203 compares the reference value (scratch detection level) with the value of the envelope signal. The comparator 203 generates a flaw detection signal ((d) in FIG. 8). Therefore, the comparator 203 detects a flaw and outputs a flaw detection signal. The flaw detection signal is a signal indicating a flaw in a sector.

Here, in this specification, "scratch portion of sector"
Is defined as "the scratched portion on the sector".

A reference value (unrecorded portion detection level) is preset in the comparator 204.

The comparator 204 compares the reference value (unrecorded portion detection level) with the envelope signal value. The comparator 204 generates an unrecorded portion detection signal ((e) in FIG. 8). The unrecorded portion detection signal is a signal indicating the unrecorded portion of the sector. Therefore, the comparator 2
04 detects an unrecorded portion of the sector and outputs an unrecorded portion detection signal.

Here, in this specification, the "unrecorded portion of the sector" is defined as "a portion of the sector in which no information is recorded".

In the present invention, the comparator 203 functions as a flaw detecting section. Comparator 204
In the present invention, functions as an unrecorded portion detection unit.

FIG. 8 shows a waveform of an input signal to the flaw / unrecorded portion detection unit 115 and a waveform of an output signal from the flaw / unrecorded portion detection unit 115.

FIG. 8A shows a scratch / unrecorded portion detection unit 115.
The waveform of the input signal to is shown.

FIG. 8B shows the waveform of the signal output from the low pass filter 201.

FIG. 8C shows the envelope detection circuit 20.
The waveform of the envelope signal output from 2 is shown.

FIG. 8D shows the scratch / unrecorded portion detection unit 115.
The scratch detection signal output from is shown.

FIG. 8E shows the scratch / unrecorded portion detection unit 115.
3 shows an unrecorded portion detection signal output from the.

With reference to FIG. 3 again, the description of the optical disk reproducing apparatus 100 of the present invention will be continued.

When the system controller 117 detects the flaw detection signal or the unrecorded portion detection signal output from the flaw / unrecorded portion detection unit 115, the gate signal generation unit 1
A signal is output to 13 to prevent the address part gate signal and the data part gate signal from being output. Therefore,
While the flaw / unrecorded portion detection unit 115 detects the flaw portion or the unrecorded portion, the system controller 117 keeps the data P
The phase comparison of the LL circuit 112 is temporarily stopped.

FIG. 9 shows the structure of the unrecorded sector discriminator 118.

The unrecorded sector discrimination section 118 includes a sector reproduction time measurement section 401, an unrecorded time measurement section 402, a calculator 403, and a comparator 405.

The sector reproduction time measuring section 401 measures the time interval (reproduction time of the sector) in which the light beam emitted from the head unit 102 passes through the sector to be reproduced. The sector reproduction time measuring unit 401 outputs sector reproduction time data indicating the measured reproduction time of the sector.

The unrecorded portion detection signal output from the flaw / unrecorded portion detecting portion 115 is input to the unrecorded time measuring portion 402.

The unrecorded time measuring unit 402 measures the reproduction time of the unrecorded portion of the sector and outputs unrecorded time data ((c) of FIG. 10) indicating the measured reproduction time of the unrecorded portion.

The system controller 117 sends a reset signal to the sector reproduction time measuring section 401 and the unrecorded time measuring section 402 each time the address section is detected. The sector reproduction time measurement unit 401 clears the sector reproduction time data each time it receives the reset signal. The unrecorded time measurement unit 402 clears the unrecorded time data each time it receives the reset signal.

The calculator 403 calculates the values of the sector reproduction time data and the unrecorded time data.

When the computing unit 403 is a subtractor, the difference between the sector reproduction time data and the unrecorded time data is output from the subtractor. When the computing unit 403 is a divider, the ratio between the sector reproduction time data and the unrecorded time data is output from the divider.

The operation of the arithmetic unit 403 when a divider is used as the arithmetic unit 403 will be described.

The divider 403 is an unrecorded part time measuring device 40.
A value obtained by dividing the output of No. 2 by the output of the sector reproduction time measuring unit 401 is output and sent to the comparator 405.

The comparator 405 determines whether or not the sector being reproduced is unrecorded by comparing the reference value with the output value from the divider 403, and outputs an unrecorded sector determination signal. When the value of the signal output from the calculator 403 is equal to or higher than the unrecorded sector detection level, the comparator 405 outputs the unrecorded sector determination signal ((d) in FIG. 10) to the system controller 117. The unrecorded sector discrimination signal is a signal indicating whether or not the sector being reproduced is unrecorded.

A reference value (unrecorded sector detection level) is set in the comparator 405.

The arithmetic unit 403 and the comparator 405 are
In the present invention, it functions as a sector discrimination unit. The sector discriminating unit discriminates whether or not the sector is an unrecorded sector based on the relationship between the sector reproduction time data and the unrecorded time data.

FIG. 10 shows a comparison between the signal generated by the unrecorded sector discrimination device 118 and the RF signal.

FIG. 10A shows an RF signal.

FIG. 10B shows the sector reproduction time measuring unit 4
01 indicates the sector reproduction time data measured.

FIG. 10C shows the unrecorded time measuring section 402.
Shows the unrecorded time data measured by. Figure 10 (d)
Indicates an unrecorded sector discrimination signal output by the unrecorded sector discrimination device 118.

According to the optical disk reproducing apparatus of the present invention, since it is determined whether or not the sector is an unrecorded sector based on the relationship between the sector reproduction time data and the unrecorded time data, it is located inside the optical disk. Even when the reproduction speed of the sector and the reproduction speed of the sector on the outer peripheral side of the optical disc are different (for example, in the case of CAV reproduction), it is possible to determine whether or not the sector is an unrecorded sector. This is because the relationship between the sector reproduction time data and the unrecorded time data does not depend on the reproduction speed of the sector. Also, in the case of CLV reproduction, CLV control may not be accurately performed immediately after a seek, and the reproduction speed of the sector may differ for each sector. However, even in this case, it is possible to determine whether or not the sector is an unrecorded sector. This is because the relationship between the sector reproduction time data and the unrecorded time data does not depend on the reproduction speed of the sector.

When the reproduction time of the sector does not change (for example, during CLV reproduction), it may be determined as an unrecorded sector if the difference between the sector reproduction time data and the unrecorded time data is less than a predetermined value. .

During the period in which the scratch / unrecorded portion detection unit 115 detects a scratch on the optical disk, the unrecorded time measurement unit 40 is used.
The second measurement or the output of the unrecorded time data is temporarily stopped. In this case, the unrecorded sector discrimination unit 40
3 does not erroneously discriminate a scratch on the sector as an unrecorded portion, the discrimination accuracy of the unrecorded sector is further improved, and the unrecorded sector can be discriminated more stably.

In addition, during the period in which the scratch / unrecorded portion detecting portion 115 detects the address portion, the sector reproduction time measuring device 401
Is configured to suspend the measurement of or the output of the sector reproduction time data. In this case, the sector reproduction time measuring device 401 does not measure the address part, but measures the reproduction time of only the data part which may be an unrecorded part. Therefore, the accuracy of identifying the unrecorded sector is further improved, and the unrecorded sector can be identified more stably.

3. Hold of Wobble PLL Circuit Next, a predetermined period including the period in which the address part is detected,
The operation of the gate signal generation unit 113 that holds the wobble PLL circuit 108 will be described.

FIG. 11 shows the configuration of the gate signal generator 113.

The gate signal generator 113 includes a counter 60.
1, the address section gate signal generation section 602, the selector 603, the data section gate signal generation section 604, the switch 605, and the wobble PLL gate signal generation section 606.
And a selector 607.

The counter 601 is the wobble PLL circuit 1
The wobble clock signal output from 08 is counted. The counter 601 determines the count value based on the number of times the wobble clock signal is output. Counter 6
01 detects the address read signal output from the system controller 117, and resets the count value.

The counter 601 outputs the count value to the address section gate signal generation section 602, the data section gate signal generation section 604, and the wobble PLL gate signal generation section 606.

Operations of the address section gate signal generation section 602 and the data section gate signal generation section 604 will be described later with reference to FIG.

The operation of the wobble PLL gate signal generation unit 606 and the "predetermined period including the period in which the address portion is detected" will be described later with reference to FIG.

The selector 607 selects either the address detection signal or the signal output from the wobble PLL gate signal generation unit 606 as the system controller 1.
It selects based on the wobble PLL gate switching signal output from 17, and outputs the selected signal as a wobble PLL gate signal.

The selector 603 selects either the address detection signal or the signal output from the address gate signal generator 602 as the system controller 117.
A gate switching signal output from the above is selected, and the selected signal is output as an address part gate signal.

The gate signal generator 113 selects the address gate signal from the selector 11 while the address is detected.
Output to 0.

Further, the gate signal generating section 113 selects the data section gate signal during the period in which the data section is detected by the selector 11.
Output to 0.

Further, the gate signal generating section 113 is a data PLL circuit during the period when the address section is detected when the data section is not reproduced, and during the phase comparison between the address section and the data section when the data section is reproduced. The address section gate signal and the data section gate signal are output to 112.

Further, the gate signal generation section 113 outputs the address section gate signal to the address read section 116.

FIG. 12 shows signals output from the respective components included in the gate signal generator 113.

FIG. 12A shows an address part and a data part included in the sector.

FIG. 12B shows the count value output from the counter 601. As the counter 601 inputs the wobble clock signal, the count value increases.
When the counter 601 detects the address part detection signal,
Reset the count value.

FIG. 12C shows an address part detection signal.

FIG. 12D shows a signal output from the wobble PLL gate signal generator.

The operation of the address section gate signal generation section 602 and the data section gate signal generation section 604 will be described with reference to FIG.
The following description will be made using 2.

The threshold value 703 shown in FIG.
When the counter 601 resets the count value (time t
₃ or the count value at time t ₅ ) is shown. Figure 12 (b)
The threshold value 704 shown in ( ₁ ) indicates the count value when a predetermined period (time period 723) has elapsed (time t ₄ ) since the count value was reset (time t ₃ ). When a predetermined period (period 724) has elapsed from time t ₄ (time t ₅ ), the counter 601
Resets the count value.

The address section gate signal generation section 602 determines the counter value when the counter value output from the counter 601 reaches the threshold value 703 (time t ₃ ) based on the counter value output from the counter. The period (period 723) until the threshold value 704 is reached (time t ₄ ) is detected. This period is output from the address section gate signal generation section 602 as time data for detecting the address section. This output is output as the address section gate signal through the selector 603.

The data section gate signal generation section 604 determines the counter 6 based on the counter value output from the counter.
A period (period 724) from when the counter value output from 01 reaches the threshold value 704 (time t ₄ ) to when the counter value reaches the threshold value 703 (time t ₅ ) is detected. This period is output from the data section gate signal generation section 604 as time data for detecting the data section. This output is output as a data part gate signal through the switch 605.

The operation of wobble PLL gate signal generator 606 and "a predetermined period including the period in which the address portion is detected" will be described below with reference to FIG.

The threshold value 702 shown in FIG.
After detecting the address part 711, a predetermined period (period 7
21) Indicates the count value when the time has elapsed (time t ₁ ). 12
The threshold value 701 shown in (b) indicates a count value when a predetermined period (period 722) has elapsed (time t ₂ ) since the address portion 712 was detected. Therefore, the predetermined period (period 722) is a period from when the address unit 712 is detected to when the count value becomes equal to or more than the threshold value 701. "Predetermined period including the period when the address part was detected"
Is, for example, the period from time t ₁ to time t ₂ .

Wobble PLL gate signal generator 606
Is the threshold value 70 output from the counter 601 based on the counter value output from the counter.
When the counter value reaches 2 (time t ₁ ), the counter value becomes the threshold value 7
The period until 01 (time t ₂ ) is detected. In this period, the wobble PLL gate signal generator 6 is used as data indicating a predetermined period including the period in which the address part is detected.
It is output from 06 to the selector 607.

Referring back to FIGS. 3, 11 and 12, the description of gate signal generator 113 will be continued.

When the selector 607 selects the signal output from the wobble PLL gate signal generation unit 606 and outputs this signal as the wobble PLL gate signal to the gate signal generation unit 113, at time t ₁ , the gate signal generation unit 1
13 starts holding the wobble PLL circuit 108. At time t ₂ , the gate signal generator 113 stops holding the wobble PLL circuit 108.

The predetermined period (period 721) indicates the first predetermined period in the present invention. Predetermined period (period 72
2) shows the second predetermined period in the present invention.

The gate signal generator 113 functions as a PLL hold unit in the present invention.

FIG. 13 shows the configuration of the wobble PLL circuit 108.

The wobble PLL circuit 108 includes a phase comparator 501, a switch 502, a phase compensator 503, a variable oscillator 504, and a division cycle 505.

The phase comparator 501 compares the wobble clock signal divided by the frequency divider 505 with the phase of the wobble signal. The output from the phase comparator 501 is switched by the switch 5 so that the wobble clock signal is synchronized with the wobble signal.
02 and the phase compensator 503, and is input to the variable oscillator 504.

The wobble PLL circuit 108 receives the wobble PLL gate signal output from the gate signal generator 113. Therefore, the switch 502 is turned off and the wobble PLL circuit 108 is held for a predetermined period including the period in which the address portion is detected.

The wobble PLL circuit 108 functions as the PLL section or the second PLL section in the present invention.

According to the optical disk reproducing apparatus of the present invention, the PLL section is held for a predetermined period including the period in which the address section is detected, so that the address section can be accurately detected based on the clock signal. This is because there is no period in which the clock signal is disturbed in a period other than the predetermined period including the period in which the address portion is detected.

According to the optical disk reproducing apparatus of the present invention, the wobble PLL gate signal is generated by the count value of the counter which operates by the wobble clock signal. However, when the reproduction speed of the sector does not change during CLV reproduction or the like, the wobble PLL gate signal may be generated according to the count value of the counter that operates with a fixed clock signal.

A wobble PLL gate signal may be raised when the count value reaches a predetermined value by using a counter that counts the number of periods of the wobble signal. This is because the number of cycles of the wobble signal is fixed.
In this case, the wobble PLL gate signal can be reliably generated even when the wobble clock is not synchronized with the wobble signal.

4. Different frequency of data read clock signal
Constant Detection The optical disc reproducing apparatus 100 of the present embodiment may include a data read clock abnormality detector 119.

Data read clock abnormality detector 119
Detects an abnormality in the frequency of the data read clock signal based on the relationship between the data read clock signal and the wobble clock signal.

FIG. 14 shows the configuration of the data read clock abnormality detector 119.

Data read clock abnormality detector 119
Includes a period measuring device 801, an amplifier 802, a period measuring device 803, a calculator 804, an absolute value calculator 805, and a comparator 806.

The period measuring device 801 is the data PLL circuit 1
The data read clock signal output from 12 is received, and the period of the data read clock signal is measured.

The period measuring device 803 receives the wobble clock signal output from the wobble PLL circuit 108,
Measure the period of the wobble clock signal.

The amplifier 802 amplifies the measurement result measured by the period measuring device 801.

Operation unit 804 performs an operation based on the relationship between the data read clock signal and the wobble clock signal.

The value output from the arithmetic unit 804 is subtracted by a predetermined value and input to the absolute value arithmetic unit 805. The absolute value calculator 805 calculates the absolute value of the input value.

The output of the absolute value calculator 805 indicates the deviation between the frequency of the wobble clock signal and the frequency of the data read clock signal. The output of the absolute value calculator 805 is input to the comparator 806.

The comparator 806 compares the reference value with the value of the signal output from the absolute value calculator 805. A reference value (data read clock abnormality detection level) is set in the comparator 806. Comparator 806
Outputs a data read clock abnormality detection signal.

The comparator 806 is an absolute value calculator 80.
If the magnitude of the signal output from 5 is equal to or higher than the data read clock abnormality detection level, it is determined that the frequency of the data read clock signal is abnormal.

Incidentally, the data read clock abnormality detector 1
19 functions as an anomaly detector in the present invention.

The data read clock signal indicates the first clock signal in the present invention. The wobble clock signal indicates the second clock signal in the present invention.

The system controller 117 inputs the data read clock abnormality detection signal, sends a signal to the data PLL circuit 112, and switches the selector 406. The data PLL circuit controls the data read clock signal so that the cycle of the wobble signal and the cycle of the data read clock signal become constant.

The optical disk reproducing apparatus of the present invention is the first PL
Since the frequency abnormality of the first clock signal is detected based on the relationship between the first clock signal output from the L section and the second clock signal output from the second PLL section, the frequency of the first clock signal is detected at high speed. Can detect abnormalities. This is because the relationship between the first clock signal and the second clock signal becomes clear each time the first clock signal is detected or each time the second clock signal is detected.

The arithmetic unit 804 may be a divider. In this case, the frequency abnormality of the data read clock signal is detected based on the ratio of the cycle of the data read clock signal to the cycle of the wobble clock signal. Therefore, even when the reproduction speed on the inner circumference and the outer circumference of the optical disc is different, such as CAV reproduction, it is possible to stably detect the abnormality in the frequency of the data read clock signal.

The arithmetic unit 804 may be a subtractor. In this case, an abnormality in the frequency of the data read clock signal is detected based on the difference between the cycle of the data read clock signal and the cycle of the wobble clock signal. Therefore, even when the reproduction speed does not change (for example, during CLV reproduction), it is possible to stably detect an abnormality in the frequency of the data read clock signal.

Data read clock abnormality detector 119
In the present invention functions as an abnormality detection unit. The abnormality detection unit detects an abnormality in the frequency of the first clock signal based on the relationship between the first clock signal output from the first PLL unit and the second clock signal output from the second PLL unit.

[0195]

According to the optical disk reproducing apparatus of the present invention,
In order to determine whether or not the sector is an unrecorded sector based on the relationship between the sector reproduction time data and the unrecorded time data, the reproduction speed of the sector on the inner circumference side of the optical disc and that of the sector on the outer circumference side of the optical disc are determined. Even if the reproduction speed is different (for example, CAV reproduction), it is possible to determine whether or not the sector is an unrecorded sector. This is because the relationship between the sector reproduction time data and the unrecorded time data does not depend on the reproduction speed of the sector. Also, in the case of CLV reproduction, CLV control may not be accurately performed immediately after a seek, and the reproduction speed of the sector may differ for each sector. However, even in this case, it is possible to determine whether or not the sector is an unrecorded sector. This is because the relationship between the sector reproduction time data and the unrecorded time data does not depend on the reproduction speed of the sector.

Further, according to the optical disk reproducing apparatus of the present invention, a predetermined period including the period in which the address portion is detected,
Since the PLL unit is held, the address unit can be accurately detected based on the clock signal. This is because there is no period in which the clock signal is disturbed in a period other than the predetermined period including the period in which the address portion is detected.

Furthermore, according to the optical disk reproducing apparatus of the present invention, the first clock signal of the first clock signal is output based on the relationship between the first clock signal output from the first PLL section and the second clock signal output from the second PLL section. Since the frequency abnormality is detected, the frequency abnormality of the first clock signal can be detected at high speed. This is because the relationship between the first clock signal and the second clock signal becomes clear each time the first clock signal is detected or each time the second clock signal is detected.

[Brief description of drawings]

FIG. 1 is a diagram showing zones and sectors included in an optical disc 1101.

FIG. 2 is a diagram showing a sector 905 included in a zone 903.

FIG. 3 is a diagram showing a configuration of an optical disc reproducing apparatus 100 of the present invention.

FIG. 4 is a diagram showing a configuration of an address detection unit 106.

FIG. 5 is a diagram showing waveforms of input signals to the address detection unit 106 and wobble detection unit 107 and waveforms of output signals from the address detection unit 106 and wobble detection unit 107.

FIG. 6 is a diagram showing a configuration of a data PLL circuit 112.

FIG. 7 is a diagram showing a configuration of a scratch / unrecorded portion detection unit 115.

FIG. 8 is a diagram showing a waveform of an input signal to the flaw / unrecorded portion detection unit 115 and a waveform of an output signal from the flaw / unrecorded portion detection unit 115.

FIG. 9 is a diagram showing a configuration of an unrecorded sector discrimination unit 118.

FIG. 10 is a diagram showing a comparison between a signal generated by an unrecorded sector discrimination device 118 and an RF signal.

FIG. 11 is a diagram showing a configuration of a gate signal generation unit 113.

FIG. 12 is a diagram showing signals output from each component included in the gate signal generation unit 113.

FIG. 13 is a diagram showing a configuration of a wobble PLL circuit 108.

FIG. 14 is a diagram showing a configuration of a data read clock abnormality detector 119.

FIG. 15 is a diagram showing a configuration of a conventional optical disc reproducing apparatus 1100.

FIG. 16 is a diagram showing an unrecorded sector determination unit 1118.

FIG. 17 is a diagram showing a wobble PLL circuit 1108.

FIG. 18 is a diagram illustrating wobble clock signal disturbance.

[Explanation of symbols]

100 optical disk reproducing device 102 head unit 103 Photodetector 105 Subtractor 106 address detection unit 107 Wobble detector 108 Wobble PLL circuit 109 selector 112 data PLL circuit 113 gate signal generator 115 Scratch / unrecorded area detection section 116 Address read section 117 System Controller 118 unrecorded sector discrimination unit 119 Data read clock error detector

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshihiro Kanda             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hiroyuki Yamaguchi             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5D044 BC04 CC04 DE03 DE99                 5D090 AA01 CC04 DD03 EE15 FF34

Claims (18)

[Claims] 1. A sector detection unit for detecting a sector, a sector reproduction time measurement unit for measuring a reproduction time of the sector and outputting sector reproduction time data indicating the measured reproduction time of the sector, An unrecorded portion detection unit that detects an unrecorded portion that is a portion in which no information is recorded, and an unrecorded time data that indicates the measured reproduction time of the unrecorded portion by measuring the reproduction time of the unrecorded portion. Based on the relationship between the sector reproduction time data and the unrecorded time data, it is determined whether or not the sector is an unrecorded sector indicating that the sector is in an unrecorded state. An optical disk reproducing apparatus including a sector discriminating unit. 2. The sector discriminating unit discriminates whether or not the sector is the unrecorded sector based on a difference between the sector reproduction time data and the unrecorded time data. Optical disc playback device. 3. The sector determination unit according to claim 1, wherein the sector determination unit determines whether or not the sector is the unrecorded sector based on a ratio between the sector reproduction time data and the unrecorded time data. Optical disc playback device. 4. The optical disk reproducing apparatus further includes a scratch detecting section for detecting a scratch which is a scratch generated on the sector among the sectors, and the scratch detecting section detects the scratch. The optical disc reproducing apparatus according to claim 1, wherein the unrecorded time measuring unit stops the measurement during a period. 5. The optical disk reproducing apparatus further includes a scratch detecting section for detecting a scratch that is a scratch generated on the sector among the sectors, and the scratch detecting section detects the scratch. The optical disc reproducing apparatus according to claim 1, wherein the unrecorded time measuring unit stops outputting the unrecorded time data during a period. 6. The sector detection unit further includes an address unit detection unit for detecting an address unit, and the sector reproduction time measurement unit is configured to detect the sector reproduction time data during a period in which the address unit is detected by the address unit detection unit. The optical disc reproducing apparatus according to claim 1, wherein the output of the above is stopped. 7. The optical disc reproducing device is an optical disc reproducing device for an optical disc having a track including a plurality of sectors, wherein the track is formed to wobble at a predetermined cycle, Each of the sectors has an address part and a data part, and the optical disk reproducing device outputs a wobble detecting part for detecting the wobble of the track, and a PLL for outputting a clock signal synchronized with the detected wobble cycle. The optical disc reproducing apparatus according to claim 1, further comprising: a unit and an address unit detecting unit that detects the address unit based on the clock signal. 8. The optical disk reproducing apparatus further includes a counter having a count value determined based on the number of times the clock signal is output, wherein the counter has the count value of the sector reproduction time. The optical disc reproducing apparatus according to claim 7, wherein the count value is set to a predetermined value when the value corresponding to the data is reached. 9. An optical disk reproducing apparatus for an optical disk having a track including a plurality of sectors, wherein the track is formed to wobble at a predetermined cycle, and each of the plurality of sectors has an address section. The optical disc reproducing apparatus includes a wobble detection unit that detects wobbles of the track, a PLL unit that outputs a clock signal synchronized with the detected wobble cycle, and the clock signal. An optical disc reproducing apparatus including: an address section detecting section that detects the address section based on the above; and a PLL holding section that holds the PLL section for a predetermined period including a period in which the address section is detected. 10. The address section detecting section detects a first address section and a second address section, and after the first predetermined period has elapsed since the detection of the first address section, the PLL hold section is 10. The optical disc reproducing apparatus according to claim 9, wherein the PLL hold unit starts holding the PLL unit, and after the second predetermined period has elapsed from the time when the second address unit was detected, the PLL hold unit stops the holding of the PLL unit. apparatus. 11. The optical disc reproducing apparatus according to claim 10, wherein the first predetermined period is a period that does not depend on a reproducing speed of the sector. 12. The optical disc reproducing apparatus according to claim 10, wherein the second predetermined period is a period that does not depend on a reproducing speed of the sector. 13. The optical disc reproducing apparatus according to claim 10, wherein the first predetermined period is a period determined based on the number of times the clock signal is output. 14. The optical disc reproducing apparatus according to claim 10, wherein the second predetermined period is a period determined based on the number of times the clock signal is output. 15. The optical disk reproducing device further includes a counter having a count value determined based on the number of times the clock signal is output, and the second predetermined period detects the second address portion. The optical disk reproducing apparatus according to claim 10, wherein the period is from the time until the count value of the counter becomes equal to or larger than a predetermined value. 16. An optical disc reproducing apparatus for an optical disc having a track including a plurality of sectors, wherein the track is formed to wobble at a predetermined cycle, and each of the plurality of sectors has an address section. The optical disc reproducing apparatus includes a sector detecting section for detecting a sector, a first PLL section for outputting a first clock signal synchronized with a detection cycle of the sector, and the wobble of the track. A wobble detection section for detecting a signal, a second PLL section for outputting a second clock signal synchronized with the detected wobble cycle, a first clock signal output from the first PLL section and an output from the second PLL section Abnormality detecting apparatus for detecting an abnormality in the frequency of the first clock signal based on the relation with the generated second clock signal Optical disk playback device comprising a. 17. The abnormality detecting device is the first PLL.
From the first clock signal and the second PL
The optical disc reproducing apparatus according to claim 16, wherein an abnormality in the frequency of the first clock signal is detected based on a difference from the second clock signal output from the L section. 18. The abnormality detection device includes the first PLL.
From the first clock signal and the second PL
17. The optical disc reproducing apparatus according to claim 16, wherein an abnormality in the frequency of the first clock signal is detected based on the ratio with the second clock signal output from the L section.