JP2766147B2 - Optical disk recording and playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus for recording / reproducing information on / from an optical disk having a track formed by pits and a track formed by grooves.

[0002]

2. Description of the Related Art As shown in FIG.
1 and a track formed by grooves 152, the pit area is used exclusively for reproduction, and the groove area is used for recording and reproduction. Normally, in the pit area, physical information such as the reflectance of the optical disk 101, the optical power required for recording, and the recordable area are recorded in advance. For this reason, when using the above-mentioned optical disk 101, it is indispensable to read the information in the pit area. On the other hand, the user can freely record information in the groove area.

An example of an optical disk recording / reproducing apparatus for recording / reproducing information by using the above-mentioned optical disk 101 is shown in FIG.
Shown in

[0004] From the optical pickup 102 to the optical disk 10
1 is irradiated with a light beam 150, and the reflected light from the optical disk 101 returns to the optical pickup 102 again and is converted into an electric signal. Based on the electric signal, the tracking error signal generation circuit 103 generates a tracking error signal S1 for tracking servo. The tracking error signal S1 is sent to a phase compensation circuit 111 and a low-pass filter 112 via a polarity switching switch 109 and a tracking servo ON / OFF switch 110.

The controller 116 includes a switch 109
, The polarity of the tracking error signal S1 is changed as necessary, as will be described later.
To reverse. Further, the controller 116 controls the switch 110 to select ON / OFF of the tracking servo.

The output of the phase compensation circuit 111 is
4 The drive circuit 114 drives an actuator (not shown) for causing the light beam to follow the track.

The output of the low-pass filter 112 is sent to a drive circuit 115. The drive circuit 115 drives a feed mechanism (not shown) that moves the optical pickup 102 in the radial direction of the optical disc 101. Switch 1
If the tracking servo is turned off by 10
The drive circuit 115 moves the optical pickup 102 to the optical disc 1 in accordance with the applied voltage from the feed voltage application circuit 113.
Then, the feed mechanism is driven so as to move the inner side or the outer side of No. 01. The controller 116 controls the feed voltage application circuit 113 to determine the applied voltage.

The outputs of the drive circuits 114 and 115 are fed back to the optical pickup 102.

When the advance information is recorded in the groove of the optical disk 101, the advance information detection circuit 104 detects the advance information signal S from the electric signal from the optical pickup 102.
4 is extracted. The absolute address detection circuit 107 obtains the absolute address of the optical disc 101 from the advance information signal S4. The controller 116 performs access control by the drive circuit 114 based on the absolute address.

A reproduction signal arithmetic circuit 105 reproduces information recorded on a track from an electric signal from the optical pickup 102. The controller 116 controls the reproduction signal operation circuit 105 to change the operation processing method when reproducing the information in the pit area and when reproducing the information in the groove area. The reproduction signal S11 from the reproduction signal calculation circuit 105 is sent to the reproduction data processing circuit 108, where digital data is obtained. Part of the digital data is sent to the controller 116.

Using the above optical disk recording / reproducing apparatus,
FIG. 13B shows a tracking error signal S1 obtained from the vicinity of the boundary between the pit area and the groove area of the optical disc 101 (FIG. 13A). FIG. 11C shows a reproduced signal S11 of the pit information obtained from the reproduced signal arithmetic circuit 105. Note that the tracking error signal S1 is obtained by a three-beam method.

The track interval of the optical disk 101 is generally 1.6 μm for both the pit area and the groove area.
The width of the pit 151 is 0.7 μm or less,
2 has a width of 1.0 μm or more. The diameter of the light beam 150 is about 1.0 μm. Therefore, in the pit area, the light beam 150 becomes a just track at the zero cross point where the tracking error signal S1 transitions from the peak to the valley. Light beam 150
Is just track.

Therefore, when shifting from the pit area to the groove area, the tracking servo is temporarily turned off by the switch 110 based on a command from the controller 116, and in this state, the voltage is sent from the feed voltage application circuit 113 to the drive circuit 115. The optical pickup 102 is applied for a predetermined time.
Is moved to the groove area by the feed mechanism. When the movement is completed, the switch 109 is set to the inverting amplifier 10.
6 and the polarity of the tracking error signal S1 is inverted. Then, the tracking servo is turned on by the switch 110.

When shifting from the groove area to the pit area, a process reverse to the above process is executed.

Thus, in both the pit area and the groove area, the light beam 150 is just shifted at the zero cross point where the tracking error signal S1 transitions from a peak to a valley.
Become a truck. For this reason, tracking becomes easy.

[0016]

However, in the above-described conventional configuration, in order to surely move the optical pickup 102 from the pit area to the groove area or from the groove area to the pit area, the optical pickup 102 is driven by the feed voltage application circuit 113. A longer voltage is applied to the circuit 115. For this reason,
There is a problem that the processing time is slow and the access time is also slow.

[0017]

According to a first aspect of the present invention, there is provided an optical disk recording / reproducing apparatus for irradiating an optical disk having a pit area and a groove area with a light beam and providing a tracking error signal. In an optical disc recording / reproducing apparatus for recording / reproducing information while tracking based on an area, an area for outputting an area discrimination signal indicating whether a light beam is irradiated to a pit area or a groove area based on the level of a tracking error signal. A distinctive circuit is provided.

According to a second aspect of the present invention, an optical disk recording / reproducing apparatus irradiates an optical disk having a pit area and a groove area with a light beam.
In an optical disc recording / reproducing apparatus for recording / reproducing information while tracking based on a tracking error signal, a prior information signal obtained from a groove area as an area discrimination signal indicating whether a light beam is irradiated to a pit area or a groove area. Alternatively, an area discriminating circuit for outputting based on the presence or absence of a reproduced signal of pit information obtained from a pit area is provided.

According to a third aspect of the present invention, there is provided an optical disk recording / reproducing apparatus according to the first or second aspect of the present invention, wherein the area discrimination signal indicates that at least the When the time required for one rotation is unchanged, an area determination circuit for outputting an area determination signal indicating whether the light beam is irradiated to the pit area or the groove area is provided.

According to a fourth aspect of the present invention, there is provided an optical disk recording / reproducing apparatus according to the first or second aspect, wherein a pit is recorded on the basis of the area discrimination signal. It is characterized in that control means for turning on / off the servo is provided so that the light beam is tracked to a desired area of either the area or the groove area.

[0021]

According to the first aspect of the present invention, it is possible to determine whether the light beam is irradiated to the pit area or the groove area. Therefore, the optical pickup can be moved from the pit area to the groove area or from the groove area to the pit area. It is possible to quickly and reliably move to the area.

According to the configuration of the second aspect, there is an operation similar to the operation of the first aspect.

According to the structure of the third aspect, in addition to the functions of the first and second aspects, even when the optical disk is eccentric, the optical pickup can be moved from the pit area to the groove area.
Alternatively, it is possible to quickly and reliably move from the groove area to the pit area.

According to the structure of the fourth aspect, in addition to the functions of the first and second aspects, even when the optical disk is eccentric, the light beam is tracked to a desired area of the pit area or the groove area. be able to.

[0025]

1 and 2 show a first embodiment of the present invention.
This will be described below.

As shown in FIG. 1, the optical disk recording / reproducing apparatus of the present embodiment irradiates an optical disk 1 with a light beam 50, receives reflected light from the optical disk 1, and converts the light into an electric signal. Based on this electric signal, a tracking error signal S for tracking servo is used.
1 and a inversion amplifier 6 for inverting the polarity of the tracking error signal S1
And a switch 9 for switching the polarity of the tracking error signal S1 and a switch 10 for turning on / off the tracking servo.

Further, the optical disk recording / reproducing apparatus comprises a phase compensation circuit 1 for compensating the phase of the tracking error signal S1.
1, an actuator drive circuit 14 for driving a tracking actuator (not shown) based on the output of the phase compensation circuit 11, and a low-pass filter 1 for extracting a low-frequency component of the tracking error signal S1.
2, a feed mechanism driving circuit 15 for driving a feed mechanism (not shown) for moving the optical pickup 2 in the radial direction of the optical disk 1 based on the output of the low-pass filter 12, and a switch 10 to turn off the tracking servo. A feed voltage application circuit 13 for applying a voltage for moving the optical pickup 2 to the inner circumference side or the outer circumference side of the optical disc 1 to the feed mechanism drive circuit 15 when the optical pickup 2 is moved is provided.

Further, the optical disk recording / reproducing apparatus includes a pre-recorded information detecting circuit 4 for extracting pre-recorded information pre-recorded in the groove based on the electric signal from the optical pickup 2.
An absolute address detection circuit 7 for obtaining an absolute address of the optical disc 1 from prior information, a reproduction signal arithmetic circuit 5 for extracting a reproduction signal from an electric signal from the optical pickup 2,
A reproduction data processing circuit 8 for converting a reproduction signal into digital data, an access control based on an absolute address from an absolute address detection circuit 7, and an optical disk 1
A controller 16 is provided for performing processing such as changing the arithmetic processing method of the reproduced signal arithmetic circuit 5 when reproducing information in the pit area and when reproducing information in the groove area.

The optical disk recording / reproducing apparatus of this embodiment further has an area determining circuit for determining whether the light beam 50 is located in the pit area or the groove area of the optical disk 1. ing. The region discriminating circuit includes a reference voltage source 17, a comparator 18, and a retriggerable one-shot circuit 19 externally provided with a resistor R1 and a capacitor C1.

The reference voltage (V _ref1 ) output from the reference voltage source 17 is equal to the tracking error signal S in the pit area.
1 and a voltage lower than the peak level of the tracking error signal S1 in the groove area. In the pit area, there are a pit portion and a pit-free portion (mirror portion), so that the signal amount of the tracking error signal S1 is smaller than that of the groove region. Therefore, the peak level of the tracking error signal S1 in the pit area is smaller than the peak level of the tracking error signal S1 in the groove area.

The comparator 18 compares the voltage of the tracking error signal S 1 from the tracking error signal generating circuit 3 with the reference voltage from the reference voltage source 17. The output signal S2 of the comparator 18 goes high when the voltage of the tracking error signal S1 is higher than the reference voltage.

The retriggerable one-shot circuit 19
The area determination signal S3 based on the output signal S2 of the comparator 18
Is output. The area discrimination signal S3 goes high at the rising edge of the output signal S2 of the comparator 18. The period during which the region determination signal S3 is maintained at the high level is set by the resistor R1 and the capacitor C1, as described later.

In the above configuration, when the light beam 50 crosses the boundary between the pit area and the groove area, the tracking error signal S1 changes as shown in FIG. When the tracking error signal S1 is input to the comparator 18, the output signal S2 of the comparator 18 becomes a low level in the pit area and a narrow pulse train in the groove area as shown in FIG. Become.

When the output signal S2 of the comparator 18 is input to the retriggerable one-shot circuit 19, one of the pulse trains
At the rising edge of the third pulse, the area determination signal S3
Becomes a high level as shown in FIG. The period during which the region determination signal S3 is maintained at the high level is set to be longer than the pulse interval of the pulse train.
Therefore, while the pulse train is being input from the comparator 18, the area determination signal S3 maintains the high level. When the last pulse of the pulse train is input to the retriggerable one-shot circuit 19, the area discrimination signal S3 keeps the high level for a certain period of time and then goes low.

As described above, when the light beam 50 is located in the pit area, the area discrimination signal S3 becomes low level, and when the light beam 50 is located in the groove area, the area discrimination signal S3 becomes high. Become a level. Therefore, the pit area and the groove area can be determined based on the level of the area determination signal S3.

The switch 9 for switching the polarity of the tracking error signal S1 can be automatically controlled by the area discrimination signal S3. That is, when the light beam 50 is located in the pit area, the polarity of the tracking error signal S1 is not inverted, and when the light beam 50 is located in the groove area,
The tracking error signal S1 is inverted by the inverting amplifier 6.

Further, the controller 16 can recognize the area where the optical pickup 2 is located by the area discrimination signal S3. Thereby, the controller 1
Numeral 6 allows the optical pickup 2 to be quickly moved to the pit area or the groove area.

A second embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The structure of the area discriminating circuit is different between the optical disk recording / reproducing apparatus of the present embodiment and the optical disk recording / reproducing apparatus of the above embodiment. As shown in FIG. 3, the area determination circuit according to the present embodiment includes an envelope detection circuit 20 and a reference voltage source 2.
1 and a comparator 22.

The envelope detection circuit 20 performs envelope detection of the advance information signal S4 (wobbling signal) output from the advance recording information detection circuit 4, and converts the detection signal S5 to a comparator 22.
Output to

The reference voltage (V _ref2 ) output from the reference voltage source 21 is set to a voltage lower than the voltage of the detection signal S5 in the groove area.

The comparator 22 compares the voltage of the detection signal S5 from the envelope detection circuit 20 with the reference voltage from the reference voltage source 21 and outputs a region discrimination signal S6. When the voltage of the detection signal S5 is higher than the reference voltage,
High level.

In the above configuration, as shown in FIG.
By wobbling the groove 52 of the optical disc 1, when the absolute address is pre-recorded in the groove 52, the pre-information signal S4 is obtained when the light beam 50 crosses the groove 52. In the pit area where the pits 51 are formed, there is no wobbling, so that the prior information signal S4 cannot be obtained.

Therefore, when the light beam 50 crosses the boundary between the pit area and the groove area, the prior information signal S4
Changes as shown in FIG. This advance information signal S
4 is input to the absolute address detection circuit 7 and the envelope detection circuit 20. In the envelope detection circuit 20, a detection signal S5 as shown in FIG.

The detection signal S5 is compared with a reference voltage by the comparator 22. In the groove area, since the voltage of the detection signal S5 is higher than the reference voltage, the area determination signal S6 becomes high level as shown in FIG. On the other hand, in the pit area, since the voltage of the detection signal S5 is lower than the reference voltage, the area determination signal S6 is at a low level.

As described above, when the light beam 50 is located in the pit area, the area discrimination signal S6 becomes low level, and when the light beam 50 is located in the groove area, the area discrimination signal S6 becomes high. Become a level. Therefore, the pit area and the groove area can be determined based on the level of the area determination signal S6.

Therefore, the same effects as in the above embodiment can be obtained.

The third embodiment of the present invention will be described below with reference to FIGS. 6 and 7. For convenience of explanation, members having the same functions as those shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The optical disc recording / reproducing apparatus of the present embodiment and the optical disc recording / reproducing apparatus of the above-described embodiment differ from each other in the configuration of the area discriminating circuit. The area discriminating circuit according to the present embodiment is configured as shown in FIG.
As shown in the figure, an envelope detection circuit 26 and a reference voltage source 27
And a comparator 28.

The envelope detection circuit 26 performs the envelope detection of the reproduced signal S11 of the pit information output from the reproduced signal calculation circuit 5, and outputs the detected signal S12 to the comparator 28.

The reference voltage (V _ref3 ) output from the reference voltage source 27 is set to a voltage lower than the voltage of the detection signal S12 in the pit area.

The comparator 28 compares the voltage of the detection signal S12 from the envelope detection circuit 26 with the reference voltage from the reference voltage source 27, and outputs a region discrimination signal S13. The area determination signal S13 is at a low level when the voltage of the detection signal S12 is higher than the reference voltage.

In the above configuration, the optical pickup 2
The electrical signals S7 and S8 are input to the reproduction signal calculation circuit 5 (see FIG. 1). The reproduction signal operation circuit 5 includes a differential amplifier 23, an addition amplifier 24, and a switch 25, and obtains a difference signal S9 and a sum signal S10 of the electric signals S7 and S8, respectively.

In the pit area, the electric signals S7 and S8 have the same phase. Therefore, the difference signal S9 becomes substantially zero, and only the sum signal 10 is obtained. On the other hand, in the groove area of the magneto-optical disk (optical disk 1), the electric signal S7 ·
S8 has opposite phases to each other. Therefore, only the difference signal S9 is obtained, and the sum signal 10 becomes substantially zero.

Therefore, in the pit area, the sum signal S10
Is output as a pit information reproduction signal S11. In the groove area, the difference signal S9 is output as the magneto-optical recording information reproduction signal S1.
The controller 16 has switched the switch 25 so as to output as 1.

The sum signal S10 is a pit information reproduction signal S1.
When it is output as 1, when the light beam 50 crosses the boundary between the pit area and the groove area, the reproduced signal S11 of the pit information changes as shown in FIG. The reproduced signal S11 of the pit information is supplied to the reproduced data processing circuit 8
And the envelope detection circuit 26. In the envelope detection circuit 26, a detection signal S12 as shown in FIG.

The detection signal S12 is compared with a reference voltage by the comparator 28. In the pit area, since the voltage of the detection signal S12 is higher than the reference voltage, the area determination signal S13 goes low as shown in FIG. On the other hand, in the groove area, since the voltage of the detection signal S12 is lower than the reference voltage, the area determination signal S13 is at a high level.

As described above, when the light beam 50 is located in the pit area, the area discrimination signal S13 is at low level, and when the light beam 50 is located in the groove area, the area discrimination signal S13 is high. Become a level. Therefore, the pit area and the groove area can be determined based on the level of the area determination signal S13.

Therefore, the same effects as in the above embodiment can be obtained.

The fourth embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The area discriminating circuit of the optical disk recording / reproducing apparatus of this embodiment is different from the area discriminating circuits of the first to third embodiments in that:
The configuration is such that an area determination circuit including a retriggerable one-shot circuit 29, an AND gate 30, and an ExOR gate 33 in FIG. 8 is added.

The retriggerable one-shot circuit 29
An external resistor R2 and a capacitor C2 are provided.

In the above configuration, the area discrimination signal S3 of the first embodiment, the area discrimination signal S6 of the second embodiment, and the third
The region determination signal S14 corresponding to one of the region determination signals S13 of the embodiment is a retriggerable one-shot circuit 29.
Is input to

When the optical disc 1 is eccentric, the light beam 50 moves back and forth near the boundary between the pit area and the groove area. Therefore, the area determination signal S
14 is a pulse train that alternately switches between a high level and a low level, as shown in FIG.

This area determination signal S14 is a retriggerable signal.
When input to the one-shot circuit 29, the retriggerable
The output signal S15 of the one-shot circuit 29 goes low at the rising edge of the first pulse of the pulse train. The period (T _time ) during which the output signal S15 maintains the low level is determined by the resistor R2 and the capacitor C2, and is set to be longer than the time required for the optical disc 1 to make one rotation. Therefore, until the last pulse of the area determination signal S14 is input, the output signal S1
5 maintains the low level. When the last pulse of the pulse train is input to the retriggerable one-shot circuit 29, the output signal S15 goes low after maintaining the low level for a certain period of time, as shown in FIG.

The AND gate 30 outputs the area discrimination signal S14
And the output signal S1 of the retriggerable one-shot circuit 29
5 is obtained, and this is calculated as the groove area determination signal S16.
Output as Therefore, the groove area determination signal S
Reference numeral 16 denotes a pit area and, as shown in FIG.
The low level is set in the area near the boundary between the pit area and the groove area, where the light beam 50 moves back and forth due to the eccentricity of the optical disc 1, and the high level is set in other groove areas.

The ExOR gate 33 is connected to the output signal S15 of the retrigable one-shot circuit 29 and the AND gate 3
The exclusive OR of the groove area determination signal S16 from 0 is obtained, and this is output as a pit area determination signal S17. Accordingly, the pit area determination signal S17 has a low level in the groove area and in the area near the boundary between the pit area and the groove area where the light beam 50 comes and goes due to the eccentricity of the optical disc 1, as shown in FIG. , And goes to the high level in the other pit areas.

The groove area determination signal S16 and the pit area determination signal S17 are input to the controller 16. Thus, even if the optical disc 1 is eccentric, it is possible to recognize that the optical pickup 2 has reliably reached the target pit area or groove area.

A fifth embodiment of the present invention will be described with reference to FIGS.
The description will be made based on the following. For convenience of explanation, members having the same functions as those shown in the drawings of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The area discriminating circuit of the optical disk recording / reproducing apparatus of this embodiment is different from the area discriminating circuits of the first to third embodiments in that:
The configuration is such that a control means including the ExOR gate 31 and the OR gate 32 of FIG. 10 is added.

In the above configuration, the area discrimination signal S3 of the first embodiment, the area discrimination signal S6 of the second embodiment, and the third
The region determination signal S14 corresponding to one of the region determination signals S13 of the embodiment is a retriggerable one-shot circuit 29.
Is input to

When the optical disc 1 is eccentric, the area discrimination signal S14 is a pulse train that alternately switches between a high level and a low level as shown in FIG.

The region discrimination signal S14 is input to the polarity switch 9, and the polarity of the tracking error signal S1 is automatically switched according to the pit region or the groove region. The region determination signal S14 is also input to the ExOR gate 31.

The ExOR gate 31 outputs the area discrimination signal S1
4 and an exclusive OR of the area designation signal S18 from the controller 16 and outputs this as an output signal S19. The area designation signal S18 is set to a low level when the tracking servo is pulled in the pit area, and is set to a high level when the tracking servo is pulled in the groove area, as shown in FIG. You. Therefore, the output signal S19 of the ExOR gate 31 is as shown in FIG.

The OR gate 32 calculates the logical sum of the output signal S19 of the ExOR gate 31 and the instruction signal S20 for servo on / off from the controller 16, and uses this as the execution signal S21 for servo on / off. Output. The servo ON / OFF instruction signal S20 is set to a low level when the tracking servo is turned on, and is set to a high level when the tracking servo is turned off, as shown in FIG. Is done. Accordingly, the execution signal S21 for servo on / off from the OR gate 32 is as shown in FIG.

The servo on / off switch 10 is
It is controlled by the execution signal S21. Thus, even if the optical disc 1 is eccentric, the servo can be automatically drawn into a track in a desired pit area or groove area in accordance with the area designation signal S18 from the controller 16. Therefore, even if the optical disk 1 is eccentric, pit information or groove recording information near the boundary between the pit area and the groove area can be read.

An optical disk recording / reproducing apparatus according to the first aspect of the present invention irradiates an optical disk 1 having a pit area and a groove area with a light beam 50, and records and reproduces information while performing tracking based on a tracking error signal S1. In the optical disc recording / reproducing apparatus, the light beam 50
An area discrimination signal S3 indicating whether the light is irradiated to the pit area or the groove area is changed to a tracking error signal S
An area discriminating circuit for outputting based on the level of 1 is provided.

According to this, it is possible to determine whether the light beam 50 is applied to the pit area or the groove area. Therefore, the optical pickup 2 is moved from the pit area to the groove area or from the groove area to the pit area. It can be moved quickly and reliably.

An optical disk recording / reproducing apparatus according to the second aspect of the present invention irradiates an optical disk 1 having a pit area and a groove area with a light beam 50, and records and reproduces information while performing tracking based on a tracking error signal S1. In the optical disc recording / reproducing apparatus, the light beam 50
Is output based on the presence / absence of a prior information signal S4 obtained from the groove area or a reproduction signal S11 of pit information obtained from the pit area, indicating whether the light is irradiated on the pit area or the groove area. An area determination circuit is provided.

According to this, the same operation and effect as those of the optical disk recording / reproducing apparatus according to the first aspect of the invention can be obtained.

An optical disk recording / reproducing apparatus according to a third aspect of the present invention is the optical disk recording / reproducing apparatus according to the first or second aspect, wherein the area discrimination signals S3, S
Area determination signal S14 corresponding to any one of S6 and S13
Is constant for at least the time required for the optical disc 1 to make one revolution, the groove area determination signal S16 and the pit area determination signal S17 indicating whether the light beam 50 is irradiated on the pit area or the groove area.
Is provided.

According to this, in addition to the functions and effects of the optical disk recording / reproducing apparatus according to the first and second aspects of the present invention, even when the optical disk 1 is eccentric, the optical pickup 2 is moved from the pit area to the groove area. Alternatively, it is possible to quickly and reliably move from the groove area to the pit area.

An optical disk recording / reproducing apparatus according to a fourth aspect of the present invention is the optical disk recording / reproducing apparatus according to the first or second aspect, wherein the area discrimination signals S3, S
Control means for turning on / off the servo so that the light beam 50 is tracked to a desired area of the pit area or the groove area based on the area determination signal S14 corresponding to any one of S6 and S13. .

According to this, in addition to the functions and effects of the optical disk recording / reproducing apparatus according to the first and second aspects of the present invention, even when the optical disk 1 is eccentric, any one of the pit area and the groove area can be selected. The light beam 50 can be made to track the area.

[0085]

As described above, the optical disc recording / reproducing apparatus according to the first aspect of the present invention converts the area discrimination signal indicating whether the light beam is irradiated to the pit area or the groove area to the level of the tracking error signal. Since an area discriminating circuit that outputs the light beam based on the light beam is provided, it is possible to discriminate whether the light beam is applied to the pit area or the groove area. As a result, the optical pickup can be quickly and reliably moved from the pit area to the groove area or from the groove area to the pit area.

As described above, the optical disk recording / reproducing apparatus according to the second aspect of the present invention provides a reproduction signal or a reproduction signal obtained from the groove area, which indicates whether the light beam is applied to the pit area or the groove area. Since an area discriminating circuit for outputting based on the presence / absence of a reproduction signal obtained from the pit area is provided, the same effect as the first aspect can be obtained.

According to a third aspect of the present invention, there is provided an optical disk recording / reproducing apparatus according to the first or second aspect, wherein the area discrimination signal is at least one rotation of the optical disk. 3. An area determination circuit for outputting an area determination signal indicating whether the light beam is irradiated to the pit area or the groove area when the time required for the operation is unchanged is provided. In addition, even when the optical disk is eccentric, the optical pickup can be quickly and reliably moved from the pit area to the groove area or from the groove area to the pit area.

According to a fourth aspect of the present invention, there is provided an optical disk recording / reproducing apparatus according to the first or second aspect, wherein the pit area or the groove area is determined based on the area determination signal. The control means for turning on / off the servo so as to make the light beam track in any desired area is provided.
In addition to the effects of (1) and (2), even if the optical disk is eccentric, the light beam can be tracked to a desired area of either the pit area or the groove area.

[Brief description of the drawings]

FIG. 1, showing a first embodiment of the present invention, is a block diagram illustrating a schematic configuration of an optical disk recording / reproducing apparatus.

FIG. 2 is a waveform diagram showing an operation of an area discriminating circuit of the optical disc recording / reproducing apparatus of FIG.

FIG. 3, showing a second embodiment of the present invention, is a block diagram illustrating an area discriminating circuit of the optical disk recording / reproducing apparatus.

FIG. 4 is a waveform chart showing an operation of the area determination circuit of FIG. 3;

FIG. 5 is an explanatory diagram showing a relationship between a tracking error signal and an advance information signal.

FIG. 6, showing a third embodiment of the present invention, is a block diagram illustrating an area discriminating circuit of an optical disc recording / reproducing apparatus.

FIG. 7 is a waveform chart showing an operation of the area determination circuit of FIG. 6;

FIG. 8 illustrates a fourth embodiment of the present invention, and is a block diagram illustrating an area determining circuit of an optical disk recording / reproducing apparatus.

FIG. 9 is a waveform chart showing an operation of the area determination circuit of FIG. 8;

FIG. 10 is a block diagram showing a fifth embodiment of the present invention and showing control means for automatic pull-in of a tracking servo of an optical disk recording / reproducing apparatus.

11 is a waveform chart showing the operation of the control means of FIG.

FIG. 12 shows a conventional example, and is a block diagram showing a schematic configuration of an optical disk recording / reproducing apparatus.

FIG. 13 is an explanatory diagram showing a relationship between a tracking error signal obtained by the optical disk recording / reproducing apparatus and a reproduced signal of pit information in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 optical disk 2 optical pickup 3 tracking error signal generation circuit 4 pre-recorded information detection circuit 5 reproduction signal calculation circuit 9 switch 10 switch (control means) 16 controller 17 reference voltage source (region determination circuit) 18 comparator (region determination circuit) 19 Retriggerable one-shot circuit (region discriminating circuit) 20 Envelope detection circuit (region discriminating circuit) 21 Reference voltage source (region discriminating circuit) 22 Comparator (region discriminating circuit) 26 Envelope detecting circuit (region discriminating circuit) 27 Reference voltage Source (region discrimination circuit) 28 Comparator (region discrimination circuit) 29 Retriggerable one-shot circuit (region decision circuit) 30 AND gate (region decision circuit) 31 ExOR gate (control means) 32 OR gate (control means) 33 ExOR gate (Area determination circuit) 51 pits 52 grooves

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuo Nakata 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Nobuo Ogata 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (56) References JP-A-4-302833 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 7/085 G11B 7/00

Claims (4)

(57) [Claims] 1. An optical disk recording / reproducing apparatus for irradiating an optical disk having a pit area and a groove area with a light beam and recording / reproducing information while tracking based on a tracking error signal, wherein the light beam has a pit area or a groove area. An optical disc recording / reproducing apparatus, comprising: an area discriminating circuit for outputting an area discriminating signal indicating which of the two is irradiated based on the level of the tracking error signal. 2. An optical disk recording / reproducing apparatus for irradiating an optical disk having a pit area and a groove area with a light beam and recording / reproducing information while tracking based on a tracking error signal, wherein the light beam has a pit area or a groove area. Characterized in that an area discriminating circuit is provided which outputs an area discriminating signal indicating which one is irradiated based on the presence or absence of a prior information signal obtained from the groove area or a reproduction signal of pit information obtained from the pit area. Optical disk recording and reproducing apparatus. 3. An area determination signal indicating whether a light beam is applied to a pit area or a groove area is output when the area determination signal is constant for at least a time required for the optical disk to make one rotation. 3. An area determining circuit is provided.
An optical disk recording / reproducing apparatus according to claim 1. 4. A control means for turning on / off a servo based on the area discrimination signal so as to track a light beam to a desired area, either a pit area or a groove area, is provided. An optical disk recording / reproducing apparatus according to claim 1 or 2.