JPH1064068A - Optical disk device and optical disk reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce both of the data recorded on a land and a groove on an optical disk in an optimum characteristic. SOLUTION: A system control circuit 22 outputs a switch signal to a switch circuit 44 of a tracking servo circuit 41 according to specification of land reproducing, groove reproducing of an optical disk 10, and outputs the switch signal to the switch circuit 16 also to switch a waveform equalizer circuit 14 optimizing the characteristic of the regenerative signal of the land with the waveform equalizer circuit 15 optimizing the characteristic of the regenerative signal of the groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk having concentric or spiral recording tracks of grooves and lands, in which data is recorded in both the grooves and lands, and the recorded data is transferred. The present invention relates to an optical disk device for reproducing and an optical disk reproducing method.

[0002]

2. Description of the Related Art Conventionally, a document "Video disc and DA"
Various optical disk playback systems are known as described in "Introduction to D" and "Optical disk technology". Generally, an optical disk device has a configuration as shown in FIG.

In FIG. 5, an optical disk apparatus includes a disk motor 118, a disk motor control circuit 119, a pickup head 102, a focus servo circuit 11
0, tracking servo circuit 111, amplifier 103,
Waveform equalizing circuit 127, binarizing circuit 107, PLL circuit 1
09, a demodulation circuit 108, and a system control circuit 117.

The optical disk 101 has a disk motor 11 whose rotation speed is controlled by a disk motor control circuit 119.
8 and rotate. The light amount control of a laser diode (not shown) provided in the pickup head 102, the on / off of the focus servo circuit 110, the on / off of the tracking servo circuit 111, and the disk motor control circuit 119 are transmitted from the system control circuit 117. Controlled by signals.

[0005] In the optical disc 101, pits are previously formed on the reflection surface as data. Light is emitted from the pickup head 102 to the rotating optical disk 101. The light to be irradiated is controlled by a focus servo circuit 110 and a tracking servo circuit 111 so as to focus on the reflection surface of the optical disk 101.

The irradiation light is reflected by the reflection surface of the optical disk 101 and returns to the pickup head 102. The intensity of the light returned to the pickup head 102 changes due to pits on the reflection surface of the optical disc 101. This change in light is converted into an electric signal by the pickup head 102, amplified by the amplifier 103, and input to the waveform equalization circuit 127.

[0007] Binarization circuit 1 via waveform equalization circuit 127
At 07, it is converted into a pulse signal indicating the presence or absence of a signal. From the signal converted into the pulse signal, the PLL circuit 109 extracts a synchronizing signal, detects whether there is a reproduced pulse signal in a time zone (detection window) determined by the demodulation circuit 103, and converts the detected code string into data. -Demodulated into a bit string and output as data.

In this type of optical disk reproducing system, a signal is recorded in a guide groove (groove) of the optical disk, and a waveform equalizing circuit is used so that the characteristics of the reproduced signal at that time are optimized. As described above, conventionally, data is recorded only in a guide groove (groove), and a recording mark representing data is formed in an optical disk for reproducing the groove or in a virtual guide groove in advance in an optical disk mastering process. This is an optical disc on which data is recorded by an optical disk.

In recent years, however, in order to increase the storage capacity per optical disk, guide grooves (grooves) of the optical disk and flat portions (lands) between the guide grooves as shown in FIG.
An optical disk that records data on both of them and reproduces the recorded data has been proposed (Japanese Patent Publication No. 63-63).
-57895).

However, as shown in FIG. 7, the frequency characteristic of the optical disc is MTF (Me
chanical Transfer Function) is not the same. In addition,
In some cases, the characteristics of the land and the groove are opposite to those shown in the figure.

Since the conventional reproducing circuit has one waveform equalizing circuit, when reproducing the data recorded in the groove of the optical disk, if the waveform equalizing circuit is optimally adjusted, the data recorded on the land of the optical disk can be obtained. The characteristics are not always optimal for reproducing the data, and conversely, if the waveform equalization circuit is optimally adjusted when reproducing the data recorded on the land of the optical disk, the data is recorded in the groove of the optical disk. The characteristics are not always optimal for reproducing the reproduced data, and there is a disadvantage that neither the data recorded on the groove nor the land of the optical disc can be reproduced with the optimal characteristics.

[0012]

As described above, since the data stored in the groove and the land of the optical disk is reproduced by a single waveform equalizing circuit, the data recorded in the groove of the optical disk is reproduced. When the waveform equalization circuit is optimally matched at the time of data reproduction, the data recorded on the land of the optical disc may not always have the optimal characteristics for reproducing the data recorded on the land of the optical disc. When the waveform equalization circuit is optimally matched when reproducing the data, the characteristics are not always optimal for reproducing the data recorded in the groove of the optical disc,
There is a problem that neither data recorded on the groove nor the land of the optical disc can be reproduced with optimum characteristics.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical disk apparatus and an optical disk reproducing method capable of reproducing both data recorded on a land and a groove of an optical disk with optimum characteristics.

[0014]

SUMMARY OF THE INVENTION An optical disk apparatus according to the present invention records data or recorded data on an optical disk having concentric or spiral grooves and lands using the grooves and lands. In an optical disc apparatus for reproducing, a first waveform equalizing means used when reproducing the groove of the optical disc, a second waveform equalizing means used when reproducing the land of the optical disc, the second waveform equalizing means, and the first Switching means for switching between the waveform equalizing means and the first waveform equalizing means using the switching means at the time of reproducing data recorded in the groove of the optical disk, and the data recorded on the land of the optical disk. Control means for controlling the switching to the second waveform equalizing means using the switching means when reproducing data; It is configured.

An optical disk device according to the present invention is an optical disk device for recording or reproducing recorded data on an optical disk having concentric or spiral grooves and lands, using the grooves and lands. A first waveform equalizing means used when reproducing the groove of the optical disc, a second waveform equalizing means used when reproducing the land of the optical disc, and a condensing means for condensing light on a groove or a land on the optical disc; Detecting means for detecting reflected light from the optical disk condensed by the light condensing means; signal generating means for generating a focus error signal for the optical disk based on a detection signal from the detecting means; The focusing means using the focus error signal generated by the means. Output means for outputting a drive signal as a focus, detection means for detecting the output of the drive signal output from the output means, and the first waveform equalization means and the second waveform equalization means in accordance with the detection result of the detection means. And a switching means for switching the waveform equalizing means.

An optical disk device according to the present invention is an optical disk device for recording data on or reproducing recorded data from an optical disk having concentric or spiral grooves and lands. A first waveform equalizing means used when reproducing the groove of the optical disc, a second waveform equalizing means used when reproducing the land of the optical disc, and a condensing means for condensing light on a groove or a land on the optical disc; Detecting means for detecting the reflected light from the optical disk condensed by the condensing means; and detecting the detected signal detected by the detecting means by the first waveform equalizing means or the second waveform equalizing means. Binarizing means for binarizing through
Phase comparing means for comparing the phase of the signal binarized by the binarizing means with a predetermined reference signal; detecting means for detecting an output from the phase comparing means; The first connection to the binarization means in response to
And the switching means for switching between the above-mentioned second waveform equalizing means.

An optical disk device according to the present invention is an optical disk device for recording data or reproducing recorded data on an optical disk having concentric or spiral grooves and lands, using the grooves and lands. Focusing means for focusing light on a groove or a land on the optical disc, detecting means for detecting reflected light from the optical disc focused by the focusing means, and based on a detection signal from the detecting means,
Signal generating means for generating a track error signal for the track of the optical disk, amplifying means for amplifying the track error signal generated by the signal generating means, and inverting and amplifying the polarity of the track error signal amplified by the amplifying means Inverting amplifier means, first switching means for switching between the track error signal whose polarity has been inverted and amplified by the inverting amplifier means and the track error signal amplified by the amplifying means, and a first switching means for use in reproducing the groove of the optical disk. A waveform equalizing means, a second waveform equalizing means used when reproducing the land of the optical disc, a second switching means for switching between the second waveform equalizing means and the first waveform equalizing means, When tracking to the groove of the optical disk is instructed, the first switching means is used to switch to the track error signal amplified by the amplifying means. When switched to the first waveform equalization means using said second switching means, tracking the land of the optical disk is indicated with changing, the first
The switching means is used to switch to the track error signal whose polarity is inverted and amplified by the inverting amplifying means,
And control means for controlling to switch to the second waveform equalizing means using the switching means.

An optical disk reproducing method according to the present invention is an optical disk reproducing method for reproducing data recorded on concentric or spiral grooves and lands from an optical disk having the grooves and lands. It has a first waveform equalizing means used at the time of groove reproduction of the optical disk and a second waveform equalizing means used at the time of land reproduction, and the first waveform equalizing means at the time of reproducing data recorded in the groove of the optical disk. Switching to the equalizing means, and performing control to switch to the second waveform equalizing means when reproducing data recorded on the land of the optical disc.

An optical disk reproducing method according to the present invention is an optical disk reproducing method for reproducing data recorded in concentric or spiral grooves and lands from an optical disk having the grooves and lands. An optical disc having first waveform equalizing means used for groove reproduction of the optical disc and second waveform equalizing means used for land reproduction, condensing light on a groove or land on the optical disc; Detects reflected light from the optical disc, generates a focus error signal for the optical disc based on the detection signal, and outputs a drive signal for making the condensing light into a just focus using the generated focus error signal, which is output. The output of the drive signal is detected, and the first waveform equalizing means and the second waveform etc. Characterized in that the switched and means.

An optical disk reproducing method according to the present invention is an optical disk reproducing method for reproducing data recorded in the grooves and lands on an optical disk having concentric or spiral grooves and lands. An optical disc having first waveform equalizing means used for groove reproduction of the optical disc and second waveform equalizing means used for land reproduction, condensing light on a groove or land on the optical disc; , And the detected detection signal is binarized via the first waveform equalizing means or the second equalizing means.
The phase of the binarized signal is compared with the phase of a predetermined reference signal, the output of the comparison result is detected, and the first waveform equalizing means and the second waveform equalizing means are used in accordance with the detection result. Is switched.

An optical disk reproducing method according to the present invention is an optical disk reproducing method for reproducing data recorded on concentric or spiral grooves and lands from an optical disk having the grooves and lands. The optical disc has first waveform equalizing means used for groove reproduction of the optical disc and second waveform equalizing means used for land reproduction, and condenses light on grooves or lands on the optical disc. Detecting the reflected light of the optical disk, generating a track error signal for the track of the optical disk based on the detection signal, amplifying the generated track error signal, inverting and amplifying the polarity of the amplified track error signal, When tracking to a groove is instructed, the amplified track error signal and the (1) When the tracking to the land of the optical disc is instructed, control is performed to switch to the inverted and amplified track error signal and the second waveform equalizing means. It is characterized by.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
1 shows a schematic configuration of an optical disc device 1 according to an embodiment. The optical disc apparatus 1 reproduces information on an optical disc 10 using focused light.

The optical disk device 1 includes a pickup head 12, an amplifier 13, a waveform equalizing circuit 14, and a waveform equalizing circuit 1.
5, switching circuit 16, binarization circuit 17, demodulation circuit 18, P
It comprises an LL circuit 19, a disk motor 20, a disk motor control circuit 21, a focus servo circuit 30, a tracking servo circuit 41, and a system control circuit 22.

The tracking servo circuit 41
It comprises an amplifier 42, an inverting amplifier 43, a switching circuit 44, a switch circuit 45, a compensation amplifier 46, and a power amplifier 47.

In the optical disk apparatus of the present invention, data is recorded only in a conventional guide groove (groove), and data is recorded in an optical disk for reproducing the groove or in a virtual guide groove in advance in an optical disk mastering step. Grooves can be reproduced on an optical disk on which data is recorded by forming a recording mark to represent the groove, but in this case, there is no reproduction on a land.

In the first embodiment, in the case of an optical disc which records data in both the guide groove (groove) and the flat portion (land) between the guide grooves or reproduces the recorded data, the guide groove (groove) is used. It is necessary to invert the polarity (tracking detection output polarity) of the tracking error signal for performing the tracking when performing tracking for the groove) and when performing tracking for the flat portion (land). In the case of a land, it is necessary to perform tracking by making the detection output polarity positive, and in the case of a land, by making the tracking detection output polarity reverse.

Therefore, as described above, the tracking servo circuit 41 includes the amplifier 42 as a means for amplifying the track error signal, the inverting amplifier 43 as the inverting amplifying means for inverting the polarity, and the switching circuit 44 as the switching means. Is provided. This is because the switching circuit 44 operates in response to an instruction signal from the system control circuit 22 so that the amplifier 4
2, and switches to a track error signal (negative phase) from the inverting amplifier 43 in the case of a land.

The optical disk 10 is rotated at a constant speed by a disk motor 20, for example. The disk motor 20 is controlled by a disk motor control circuit 21.

The reproduction of information from the optical disk 10 is performed by the pickup head 12. Amplifier 13
Amplifies the information reproduced by the pickup head 12. Waveform equalization circuit 1 as first waveform equalization means
No. 4 has an optimum characteristic when reproducing the land of the optical disk 10. The waveform equalizing circuit 15 as the second waveform equalizing means has optimal characteristics when reproducing the groove of the optical disk 10.

A switching circuit 16 as a switching means receives a signal for instructing the reproduction of the land or the groove of the optical disk 10 from the system control circuit 22, and receives a signal from the waveform equalizing circuit 14 or the waveform equalizing circuit 15 And outputs it to the binarization circuit 17.

In the binarizing circuit 17 as the binarizing means,
A demodulation circuit 108 converts the signal into a pulse signal representing the presence or absence of a signal.
To the PLL circuit 19. The PLL circuit 19 extracts a synchronization signal from the pulse signal from the binarization circuit 17.

The demodulation circuit 18 detects whether or not there is a reproduced pulse signal in a predetermined time zone (detection window), and demodulates the detected code sequence into a data bit sequence and outputs it as data.

The output data from the demodulation circuit 18 is output to a host computer or the like via an interface (not shown). FIG. 2 shows a schematic configuration of the pickup head 12.

The pickup head 12 is provided with an optical head 23 as a condensing means. The optical head 23 is fixed to a drive coil 28 a constituting a movable part of a linear motor 28, and the drive coil 28 a is connected to the system control circuit 22.

A linear motor position detector 29 is connected to the system control circuit 22. The linear motor position detector 29 is connected to the optical scale 2 provided on the optical head 23.
By detecting 9a, a position signal is output.

A permanent magnet (not shown) is provided at a fixed portion of the linear motor 28. When the drive coil 28a is excited by the system control circuit 22,
The optical head 23 is moved in the radial direction of the optical disk 10.

The objective lens 6 is held on the optical head 23 by a wire or a leaf spring (not shown).
The objective lens 6 is moved in the focusing direction (the optical axis direction of the lens) by the drive coil 5 and is movable in the tracking direction (the direction orthogonal to the optical axis of the lens) by the drive coil 4.

The laser light generated by the laser diode (LD) 9 driven by the system control circuit 22 is supplied to a collimator lens 24a and a half prism 24.
b, the light is radiated onto the optical disk 10 via the objective lens 6, and the reflected light from the optical disk 10 is guided to the photodetector 8 via the objective lens 6, the half prism 24b, the condenser lens 25a, and the cylindrical lens 25b. I will

The photodetector 8 as a detecting means is constituted by four divided photodetection cells 8a, 8b, 8c and 8d. The output signal of the photodetector cell 8a of the photodetector 8 is supplied to one end of an adder 27a via an amplifier 26a, and the output signal of the photodetector cell 8b is supplied to one end of an adder 27b via an amplifier 26b. The output signal of the light detection cell 8c is supplied to the other end of the adder 27a via the amplifier 26c, and the output signal of the light detection cell 8d is supplied to the other end of the adder 27b via the amplifier 26d. It has become.

The output signal of the photodetector cell 8a of the photodetector 8 is supplied to one end of an adder 27c via an amplifier 26a, and the output signal of the photodetector cell 8b is supplied to one end of an adder 27d via an amplifier 26b. The output signal of the photodetection cell 8c is supplied to the other end of the adder 27d via the amplifier 26c, and the output signal of the photodetection cell 8d is supplied to the amplifier 26d.
Is supplied to the other end of the adder 27c.

The output signal of the adder 27a is a differential amplifier OP
2, and the output signal of the adder 27b is supplied to the non-inverting input terminal of the differential amplifier OP2. Thereby, the differential amplifier OP as a signal generating means
Numeral 2 supplies a signal related to a focus point, that is, a focus error signal to the focus servo circuit 30 according to the difference between the adders 27a and 27b.
A drive signal of the focus servo circuit 30 as an output unit is supplied to a focusing drive coil 5, and the laser beam is controlled so as to be always just focused on the optical disk 10.

The output signal of the adder 27c is a differential amplifier OP
1, and the output signal of the adder 27d is supplied to the non-inverting input terminal of the differential amplifier OP1.
Thereby, the differential amplifier OP1 as a signal generating means
Supplies a track difference signal to the tracking servo circuit 41 in accordance with the difference between the adders 27c and 27d. This tracking servo circuit 41 is provided in the OP1
A track drive signal is created in accordance with the track difference signal supplied from.

The track drive signal output from the tracking servo circuit 41 is supplied to the drive coil 4 in the tracking direction. The sum signal of the outputs of the respective photodetection cells 8a to 8d of the photodetector 8 in the state where the focusing and tracking are performed as described above, that is, the output signal of the adder 27c and the output signal of the adder 27d are supplied. The output signal of the adder 27e reflects a change in reflectance from pits (stored information) formed on the track. This signal is supplied to the amplifier 13.

When the objective lens 6 is moved by the tracking servo circuit 41, the system control circuit 22
The linear motor 28, that is, the optical head 23 is moved so that the objective lens 6 is located near the center position in the optical head 23.
Is to be moved.

Next, the operation of the optical disk device 1 having such a configuration will be described with reference to FIG. The light amount control of the laser diode 9 of the optical head 23 in the pickup head 12, the on / off of the focus servo circuit 30, the on / off of the tracking servo circuit 41, and the disk motor control circuit 21 are controlled by signals from the system control circuit 22. Controlled.

In the optical disk 10, pits are previously formed on the reflection surface as data. Light is emitted from the pickup head 12 to the rotating optical disk 10. The pickup head 12 is controlled by the focus servo circuit 30 and the tracking servo circuit 41 so that the irradiation light is focused on the reflection surface of the optical disk 10.

The tracking servo circuit 41 amplifies the track difference signal from the pickup head 12 with the amplifier 42 and inputs the signal to the switching circuit 44 through the inverting amplifier 43. The output from the amplifier 42 is also input to the switching circuit 44.

The switching circuit 44 outputs the output of the amplifier 42 according to a land and groove switching signal from the system control circuit 22.
Alternatively, the output of the inverting amplifier 43 is switched. The system control circuit 22 outputs a signal for switching between land reproduction and groove reproduction of the optical disk 10 in accordance with an instruction from an external device.

The output of the switching circuit 44 is input to a switch circuit 45 for turning on / off the tracking servo circuit 41 by a signal from the system control circuit 22. The output of the switch circuit 45 is amplified by the power amplifier 47 via the compensation amplifier 12 to move the drive coil 4 of the optical head 23 in the pickup head 12, and the land or groove of the optical disk 10 is traced.

The irradiation (laser) light is reflected by the reflection surface of the optical disk 10 and returns to the pickup head 12.
The light returned to the pickup head 12 is
The intensity changes due to the pits on the reflection surface of. This change in light is converted into an electric signal by the pickup head 12, amplified by the amplifier 13, and input to the waveform equalization circuit 14 and the waveform equalization circuit 15. Waveform equalizer 14 and waveform equalizer 1
The output of 5 is input to the switching circuit 16.

The switching circuit 16 obtains land reproduction or groove reproduction instruction information of the optical disk 10 from a signal from the system control circuit 22 for switching the switching circuit 44 in the tracking servo circuit 41, and is optimal when reproducing lands. The signal from the waveform equalizing circuit 14 having the characteristic or the signal from the waveform equalizing circuit 15 having the optimal characteristic when reproducing the groove is switched to the binarizing circuit 17.
Output to

The output from the waveform equalizing circuit 14 or the waveform equalizing circuit 15 switched by the switching circuit 16 is converted by the binarizing circuit 17 into a pulse signal indicating the presence or absence of a signal. The signal converted to the pulse signal is input to a demodulation circuit 18 and a PLL circuit 19, where a synchronization signal is extracted by the PLL circuit 19, and the demodulation circuit 18 generates a reproduced pulse signal in a predetermined time zone (detection window). The presence or absence is detected, and the detected code sequence is demodulated into a data bit sequence and output as data.

As described above in detail, according to the first embodiment, both the data recorded on the land and the groove of the optical disk by the optical disk device are transmitted by the land and groove switching signal in the tracking servo circuit of the optical disk device. An optical disk device that can use an optimal waveform equalization circuit and can reproduce data with optimal characteristics can be realized.

FIG. 3 shows a schematic configuration of an optical disk device 2 according to a second embodiment of the present invention. The first
The same components as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the optical disk device 2 of the second embodiment, the tracking servo circuit 40 has the same configuration as the conventional one, and the focus servo circuit 31 is different from that of the first embodiment, and the reproduction of the optical disk 10 is controlled by the system control circuit 32.
The configuration of the pickup head 12 is as described with reference to FIG.

The focus servo circuit 31 includes an amplifier 3
3, a switch circuit 34, a compensation amplifier 35, and a power amplifier 36. The output from the power amplifier 36 is connected to the pickup head 12 and a DC
It is input to the offset level detector 37.

Here, since the reflection surface of the optical disk 10 is different between the land and the groove, the DC offset voltage output from the power amplifier 36 changes between the land and the groove. The DC offset level detector 37 can detect whether the reproduction of the optical disc 10 is a land or a groove by detecting the change of the DC offset voltage, that is, the offset level. The DC offset level detector 37 outputs a detection signal of the offset level to the switching circuit 16, and the switching circuit 16 switches between the signal from the waveform equalization circuit 14 and the signal from the waveform equalization circuit 15 according to the detection signal. . That is, the switching circuit 16 switches to the signal from the waveform equalizing circuit 14 when the reproduction of the optical disk 10 is a land, and switches to the signal from the waveform equalizing circuit 15 when the reproduction of the optical disk 10 is a groove.

Next, the operation of the optical disk apparatus 2 in such a configuration will be described with reference to FIG. The light amount control of the laser diode 9 of the optical head 23 in the pickup head 12, the on / off of the focus servo circuit 31, the on / off of the tracking servo circuit 40, and the disk motor control circuit 21 use signals from the system control circuit 32. Controlled.

In the optical disk 10, pits are previously formed on the reflection surface as data. Light is emitted from the pickup head 12 to the rotating optical disk 10. The pickup head 12 is controlled by the focus servo circuit 31 and the tracking servo circuit 40 so that the irradiation light is focused on the reflection surface of the optical disk 10.

The focus servo circuit 31 converts the focus error signal from the pickup head 12 into an amplifier 33.
And a switch circuit 3 for turning on / off the focus servo circuit 31 with a signal from the system control circuit 32
Enter 4 The output of the switch circuit 34 is the compensation amplifier 3
The drive coil 5 is driven by the power amplifier 36 via the power supply 5, and is controlled so as to focus on the reflection surface of the optical disk 10.

Since the reflection surface of the optical disk 10 is different between the land and the groove, the DC offset voltage of the power amplifier 36 changes. This change is detected by the DC offset level detector 37.

The irradiation (laser) light is reflected by the reflection surface of the optical disk 10 and returns to the pickup head 12.
The light returned to the pickup head 12 is
The intensity changes due to the pits on the reflection surface of. This change in light is converted into an electric signal by the pickup head 12, amplified by the amplifier 13, and input to the waveform equalization circuit 14 and the waveform equalization circuit 15. Outputs of the waveform equalizing circuits 14 and 15 are input to a switching circuit 16.

The switching circuit 16 switches between the signal from the waveform equalizing circuit 14 and the signal from the waveform equalizing circuit 15 according to the result of the detection of the DC offset level of the DC offset voltage from the power amplifier 36 by the DC offset level detector 37. . As a result, as described above, the waveform equalization circuit 14
And the waveform equalizing circuit 15 are switched.

Since the conventional optical disc 10 can record only the conventional groove, the switching circuit 16 is switched to the waveform equalizing circuit 15 suitable for the groove reproduction at the time of rising.

The output from the waveform equalizing circuit 14 or the waveform equalizing circuit 15 switched by the switching circuit 16 is converted into a pulse signal representing the presence or absence of a signal by the binarizing circuit 17. The signal converted to the pulse signal is input to a demodulation circuit 18 and a PLL circuit 19, where a synchronization signal is extracted by the PLL circuit 19, and the demodulation circuit 18 generates a reproduced pulse signal in a predetermined time zone (detection window). The presence or absence is detected, and the detected code sequence is demodulated into a data bit sequence and output as data.

As described above, according to the second embodiment, the land / groove switching signal is generated by the change of the DC offset of the power amplifier in the focus servo circuit of the optical disk device, and the land of the optical disk is formed by the optical disk device. Both the data recorded in the groove and the data recorded in the groove can be used with an optimal waveform equalizing circuit, and an optical disk device capable of reproducing data with optimal characteristics can be realized.

FIG. 4 shows a schematic configuration of an optical disk device 3 according to a third embodiment of the present invention. The first
The same components as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the optical disk device 3 of the third embodiment, the focus servo circuit 30 and the tracking servo circuit 40 have the same configuration as the conventional one, and the PLL circuit 51 is different from that of the first embodiment, and the reproduction of the optical disk 10 is controlled by the system control circuit 52. Is done. The configuration of the pickup head 12 is as described with reference to FIG.

The PLL circuit 51 includes a voltage control transmitter 53,
It comprises a low-pass filter 54, a phase comparator 55 as phase comparison means, and a master clock generator 56. The output from the low-pass filter 54 is input to a voltage control transmitter 53 and a DC offset level detector 57 as a detecting means.

Next, the operation of the optical disk device 3 having such a configuration will be described with reference to FIG. The light quantity control of the laser diode 9 of the optical head 23 in the pickup head 12, the on / off of the focus servo circuit 30, the on / off of the tracking servo circuit 40, and the disk motor control circuit 21 use signals from the system control circuit 52. Controlled.

In the optical disk 10, pits are previously formed on the reflection surface as data. Light is emitted from the pickup head 12 to the rotating optical disk 10. The pickup head 12 is controlled by the focus servo circuit 31 and the tracking servo circuit 40 so that the irradiation light is focused on the reflection surface of the optical disk 10.

The irradiation (laser) light is reflected on the reflection surface of the optical disk 10 and returns to the pickup head 12.
The light returned to the pickup head 12 is
The intensity changes due to the pits on the reflection surface of. This change in light is converted into an electric signal by the pickup head 12, amplified by the amplifier 13, and input to the waveform equalization circuit 14 and the waveform equalization circuit 15. Outputs from the waveform equalizing circuit 14 and the waveform equalizing circuit 105 are input to the switching circuit 16.

The switching circuit 16 switches between the signal from the waveform equalizing circuit 14 and the signal from the waveform equalizing circuit 15 according to the signal from the DC offset level detector 57. DC
The signal from the offset level detector 57 is a switching signal of the switching circuit 16 according to the land reproduction or the groove reproduction of the optical disk 10, which will be described in detail later.

The output from the waveform equalizing circuit 14 or the waveform equalizing circuit 15 switched by the switching circuit 16 is converted into a pulse signal indicating the presence or absence of a signal by the binarizing circuit 17. 2
The pulse signal converted by the value conversion circuit 17 is
And the phase comparator 55 of the PLL circuit 51. The phase comparator 55 compares the input pulse signal with the signal from the master clock oscillator 56 and outputs its output to the low-pass filter 54.

The output from the low-pass filter 54 controls the voltage-controlled oscillator 51 so as to synchronize with the basic period to extract a synchronizing signal, and the demodulation circuit 18 outputs the synchronizing signal in a predetermined time zone (detection window). It is detected whether or not there is a reproduction pulse signal therein, and the detected code sequence is demodulated into a data bit sequence and output as data.

The output of the low-pass filter 54 indicates a phase error, and is also input to the DC offset level detector 57. Since the waveform equalization circuits 14 and 15 are optimal circuits for reproducing the land or the groove of the optical disk 10, respectively, for example, when the waveform equalization circuit 15 for the groove is used when the land of the optical disk 10 is reproduced, the phase is reduced. The error of the comparator 55 increases.

In the DC offset level detector 57, when the phase error is equal to or more than a predetermined value, an appropriate waveform equalizing circuit (14
Or 15) is determined not to be used, and a signal for switching the waveform equalizing circuit (14 or 15) to the one not currently selected is generated and output to the switching circuit 16.

It is to be noted that the case where the conventional optical disk 10 is used for recording only the conventional groove is considered. For example, when the optical disk 10 rises, the switching circuit 16 is switched to the waveform equalizing circuit 15 suitable for groove reproduction.

As described above, according to the third embodiment, the land and groove switching signal is generated by the change of the DC offset of the low-pass filter in the PLL circuit of the optical disk device, and the land of the optical disk is formed by the optical disk device. Both the data recorded in the groove and the data recorded in the groove can be used with an optimal waveform equalizing circuit, and an optical disk device capable of reproducing data with optimal characteristics can be realized.

[0078]

As described in detail above, according to the present invention,
It is possible to provide an optical disk apparatus and an optical disk reproducing method capable of reproducing both data recorded on a land and a groove of an optical disk with optimum characteristics.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a pickup head.

FIG. 3 is a block diagram showing a schematic configuration of an optical disk device according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a schematic configuration of an optical disc device according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a schematic configuration of a conventional optical disk device.

FIG. 6 is a diagram showing recording on lands and grooves of an optical disc.

FIG. 7 is a diagram illustrating frequency characteristics of an optical disc.

[Explanation of symbols]

 1, 2, 3 ... Optical disk device 10 ... Optical disk 12 ... Pickup head 13 ... Amplifier 14, 15 ... Waveform equalizing circuit 16 ... Switching circuit 17 ... Binary circuit 18 ... Demodulation circuit 19, 51 ... PLL circuit 20 ... Disk motor 21: Disk motor control circuit 22, 32, 52 ... System control circuit 30, 31 ... Focus servo circuit 37, 57 ... DC offset level detector 40, 41 ... Tracking servo circuit

Claims (8)

[Claims] 1. An optical disc device for recording or reproducing data recorded on or from an optical disc having concentric or spiral grooves and lands, using the grooves and lands. First waveform equalizing means used at the time of reproduction, second waveform equalizing means used at the time of land reproduction of the optical disk, and switching means for switching between the second waveform equalizing means and the first waveform equalizing means. When the data recorded in the groove of the optical disc is reproduced, switching to the first waveform equalizing means is performed using the switching means, and when the data recorded on the land of the optical disc is reproduced, the switching means is used. Control means for performing control for switching to the second waveform equalizing means by means of an optical disk device. 2. An optical disc apparatus for recording or reproducing data recorded on or from an optical disc having concentric or spiral grooves and lands, using the grooves and lands. A first waveform equalizing means used at the time of reproduction, a second waveform equalizing means used at the time of reproducing the land of the optical disc, a condensing means for condensing light on a groove or a land on the optical disc, Detecting means for detecting the condensed reflected light from the optical disk; signal generating means for generating a focus error signal for the optical disk based on the detection signal from the detecting means; Using the focus error signal, a drive signal for setting the focusing means to just focus An output unit for outputting, a detection unit for detecting an output of a drive signal output from the output unit, a first waveform equalization unit and a second waveform equalization unit according to a detection result of the detection unit. An optical disk device, comprising: switching means for switching between the two. 3. An optical disc apparatus for recording data on or reproducing recorded data from an optical disc having concentric or spiral grooves and lands, using the groove reproduction of the optical disc. A first waveform equalizing means used at the time of reproduction, a second waveform equalizing means used at the time of reproducing the land of the optical disc, a condensing means for condensing light on a groove or a land on the optical disc, Detecting means for detecting the condensed reflected light from the optical disk; binarizing the detection signal detected by the detecting means via the first waveform equalizing means or the second waveform equalizing means Phase comparing means for comparing the phase of the signal binarized by the binarizing means with a predetermined reference signal; A detecting means for detecting an output from the phase comparing means; a first waveform equalizing means and a second waveform equalizing means connected to the binarizing means in accordance with a detection result of the detecting means. An optical disk device, comprising: switching means for switching. 4. An optical disc device for recording or reproducing recorded data on an optical disc having concentric or spiral grooves and lands, using the grooves and lands. Condensing means for condensing light on the lands; detecting means for detecting reflected light from the optical disc condensed by the condensing means; and a track for the optical disc based on a detection signal from the detecting means. Signal generating means for generating a track error signal; amplifying means for amplifying the track error signal generated by the signal generating means; inverting amplifying means for inverting and amplifying the polarity of the track error signal amplified by the amplifying means; The track error signal whose polarity has been inverted and amplified by the inverting amplifying means is amplified by the amplifying means. A first switching unit for switching the track error signal, a first waveform equalizing unit used for groove reproduction of the optical disk, a second waveform equalizing unit used for land reproduction of the optical disk, A second switching means for switching between the waveform equalizing means and the first waveform equalizing means, and when the tracking to the groove of the optical disc is instructed, the first switching means is used to amplify the signal using the first switching means. Switching to the amplified track error signal and the second
When the tracking to the land of the optical disk is instructed by using the switching means, the track whose polarity has been inverted and amplified by the inverting amplifying means using the first switching means. An optical disk device, comprising: control means for controlling to switch to an error signal and to switch to the second waveform equalizing means using the second switching means. 5. An optical disk reproducing method for reproducing data recorded on concentric or spiral grooves and lands on an optical disk having the concentric or spiral grooves and lands. A first waveform equalizing means and a second waveform equalizing means for use during land reproduction, and switching to the first waveform equalizing means when reproducing data recorded in a groove of the optical disc; A method for reproducing an optical disk, characterized in that when reproducing data recorded on a land of the optical disk, control for switching to the second waveform equalizing means is performed. 6. An optical disk reproducing method for reproducing data recorded on concentric or spiral grooves and lands on an optical disk having the grooves and lands, wherein the method is used for reproducing the grooves on the optical disk. It has a first waveform equalizing means and a second waveform equalizing means used at the time of land reproduction, focuses light on the groove or land on the optical disk, and detects reflected light reflected from the optical disk. Generating a focus error signal for the optical disk based on the detection signal, outputting a drive signal for making the light collection just focus using the generated focus error signal, and detecting an output of the output drive signal. Switching between the first waveform equalizing means and the second waveform equalizing means in accordance with the detection result. Optical disk playback method characterized by. 7. An optical disk reproducing method for reproducing data recorded on concentric or spiral grooves and lands on an optical disk having the grooves and lands, wherein the method is used for reproducing the grooves on the optical disk. It has a first waveform equalizing means and a second waveform equalizing means used at the time of land reproduction, focuses light on the groove or land on the optical disk, and detects reflected light reflected from the optical disk. Binarizing the detected detection signal via the first waveform equalizing means or the second equalizing means, comparing the phase of the binarized signal with a predetermined reference signal, A method for reproducing an optical disk, comprising detecting an output of a comparison result, and switching between the first waveform equalization means and the second waveform equalization means according to the detection result. . 8. An optical disk reproducing method for reproducing data recorded on concentric or spiral grooves and lands on an optical disk having the grooves and lands, wherein the method is used for reproducing the grooves on the optical disk. It has a first waveform equalizing means and a second waveform equalizing means used at the time of land reproduction, and condenses light on a groove or a land on an optical disc;
Detected light reflected from the optical disk, generates a track error signal for the track of the optical disk based on the detected signal, amplifies the generated track error signal, and changes the polarity of the amplified track error signal. When the tracking to the groove of the optical disc is instructed by inversion amplification, the amplified track error signal and the first
When the tracking to the land of the optical disc is instructed, control is performed to switch between the inverted and amplified track error signal and the second waveform equalizing means. A method of reproducing an optical disc, which is characterized by the following.