JPH0896417A - Optical disk medium and recording / reproducing method using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] An optical disk device that uses both lands and grooves as data areas to continuously record / reproduce all data areas without performing track jumps. [Structure] An odd number of mirror portions 1c are provided radially from the center of the optical disk medium 1, and grooves are formed so that the lands 1a and the grooves 1b are alternately replaced before and after the mirror portions 1c. Then, the mirror detecting circuit 8 detects whether or not the recording / reproducing beam exists on the mirror 1c,
When the recording / reproducing beam exists on the mirror section 1c,
The converging beam that has reached the mirror portion 1c while being tracked on the land by the polarity control circuit 9 is the groove 1
Switch to a servo polarity that is stable on b. As a result, the optical head 2 can be smoothly tracked between the land 1a and the groove 1b without being applied with a large acceleration, and stable recording / reproducing can be performed without the meandering of the optical head 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing method for an optical disk device, and more particularly to an optical disk medium using both lands and grooves as data areas, and a tracking method for the optical disk device.

[0002]

2. Description of the Related Art Optical disk devices have been applied to image data recording and digital audio data recording because of their high recording density and medium compatibility.
In these data recording / reproducing, although the access frequency between tracks is relatively low, real-time property is required. In particular, with the recent trend toward multimedia and higher definition of images, technological development for increasing the capacity of optical disc devices is also active.

One of the technologies for increasing the capacity is a method of using both the land and the groove on the optical disk medium as a data area. According to this method, the track density can be substantially doubled without narrowing the interval between the grooves, as compared with the case where only the land portion is used as the data area. Also,
The medium noise component generated depending on the groove shape can also be reduced as compared with the case where the track spacing is simply increased by narrowing the groove interval. Also, the position error signal for tracking is
There is also an advantage that it can be obtained with the same quality as an optical disc medium having a low track density.

Next, a conventional circuit configuration will be described with reference to FIG.

In FIG. 4, when both the land 30a and the groove 30b of the optical disk medium 30 are used as a data area, the width of the land 30a and the groove 30a are set in order to make the quality of both recording / reproducing signals uniform. The groove is formed so that the width of 30b substantially matches. Optical head 12
The data is input / output by the recording / reproducing circuit 15 to / from the optical disc medium 30 having such grooves, and at the same time, servo information such as focus and track position error is extracted. As a typical focus position error detection method, there is an astigmatism method, which utilizes astigmatism obtained by a cylindrical lens. Further, in the track position error detection, it is general to detect the error signal from the track center by the push-pull method.

Actually, position error signals are obtained from the outputs of a plurality of photodetectors provided in the optical head 12 by the arithmetic processing of the track error detection circuit 13 and the focus error detection circuit 14. Focus error detection circuit 14
The focus position error signal Ef detected by is given to the focus servo circuit 17 and is fed back to the optical head 12. Further, the track position error signal Et detected by the track error detection circuit 13 is "0" both when the focused beam position is at the track center of the land 30a and the track center of the groove 30b, as shown in FIG. However, it has the opposite slope to the radial position error. Therefore, by reversing the polarity of the track position error signal Et, the land 30a and the groove 30b are reversed.
You can switch the tracking to.

When the track position error signal Et is applied to the tracking servo circuit 16 with the positive polarity, the focused beam is stabilized at the center of the land 30a. Further, when the polarities are opposite, it acts so as to stabilize in the center of the groove 30b. In the polarity control circuit 19, the tracking servo circuit 6
Whether the tracking is performed on the land 30a or the groove 3 by switching the polarity of the error signal given to
Controls whether to track to 0b.

However, since the groove has been formed in a spiral shape in the past, a jump operation from the land to the groove or from the groove to the land is indispensable when recording or reproducing the data on the groove together with the land. there were.

For example, as shown in FIG. 6A, the groove 40 extends from the innermost circumference to the outermost circumference of the optical disc medium 40.
If continuous data is recorded on b, and the subsequent data starts from the innermost circumference on the land 40a, the optical head is set at the time when the recording or reproducing of the data on the land 40a is completed. It is necessary to move from the outermost circumference to the innermost circumference of the optical disc medium 40 by a track jump as shown by an arrow (wavy line). Moreover, since recording / reproducing cannot be performed while moving, real-time performance is impaired.

On the other hand, as shown in FIG. 6B, when recording / reproducing is performed in order from the inner circumference side of the optical disk medium 41 and a track jump between the land 41a and the groove 41b is performed for each circumference, It is not necessary to access from the outermost circumference to the innermost circumference, and the time interval during which recording / reproducing cannot be performed becomes relatively short. However, since a large acceleration is applied to the optical head during the track jump, the recording / reproducing beam meanders on the track immediately after the jump. If the recording operation is performed during this period, the data on the adjacent track may be lost. Therefore, it is necessary to secure the time until the tracking becomes stable as the recording prohibition time.

The existence of this time is not desirable for effectively using the optical disk medium as a recording area. Also,
This also applies to the case of using an optical disk medium having grooves formed in concentric circles.

[0012]

Real-time property is required for recording and reproducing image data and audio data. However, in an optical disk device that uses both the land and the groove as a data area, it is not possible to continuously record / reproduce all the data without a track jump between the land and the groove, which leads to a real-time property. It was difficult to be satisfied. In addition, even when a method such as performing a track jump for each round is used, it is necessary to allow for the time required for stable tracking, and there is the disadvantage that the data area cannot be used efficiently.

The object of the present invention was made in view of the above problems, and in an optical disk device that uses both a land and a groove as a data area, the entire data area is continuously written without performing a track jump. It is to provide a method of recording / reproducing.

[0014]

The present invention is characterized in that an odd number of mirror portions are provided radially from the center of an optical disk medium, and grooves are formed so that lands and grooves are alternated before and after the mirror portions. And A recording / reproducing method using this optical disc medium detects whether or not a recording / reproducing beam is present on the mirror section, and when the recording / reproducing beam is present on the mirror section, a tracking servo is performed. It is characterized by switching the polarity of.

Further, at least one mirror portion is provided radially from the center of the optical disk medium, and the land is formed at an angle obtained by equally dividing the circumferential direction by (2n + 1) (where n is a positive integer) with respect to the mirror portion. The groove is formed so that the groove and the groove alternate with each other. Also,
A recording / reproducing method using this optical disc medium detects whether or not a recording / reproducing beam is present on the mirror section,
When the recording / reproducing beam exists on the mirror section, the rotation cycle reproduced from the mirror section detection signal is set to (2)
n + 1) The polarity of the tracking servo is switched at each timing divided into equal parts.

[0016]

[Operation] Generally, recording / recording of image data and audio data
In reproduction, the access frequency is relatively low, but there is a high demand for continuous recording / reproduction of data.

According to the present invention, by using the optical disk medium which is formed such that the land and the groove are interchanged before and after the radially formed mirror portion, the land-groove gap is not applied to the optical head without applying a large acceleration. Realize the transition. As a result, the optical head does not meander, and continuous stable data recording / reproducing can be performed. Although the polarities of the tracking servo signals are opposite in the land area and the groove area, this can be dealt with by detecting the mirror portion and inverting the polarities.

[0018]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment relating to the first and third inventions. In this embodiment, as shown in FIG. 1, the optical disk medium 1 has three mirror portions radially, and the grooves are land 1a and groove 1 before and after the mirror portion 1c.
They are formed so as to alternate with b. Position error signals are respectively obtained from the outputs of a plurality of photodetectors provided in the optical head 2 by the calculation processing of the track error detection circuit 3 and the focus error detection circuit 4, and the focus position detected by the focus error detection circuit 4 is obtained. Error signal Ef
Is given to the focus servo circuit 7 as in the conventional example. Further, the tracking position error signal Et extracted by the track error detection circuit 3 by the push-pull method.
Is the tracking servo circuit 6 via the polarity control circuit 9.
Given to. Whether the tracking is performed on the land 1a or the groove 1b is determined by the tracking servo circuit 6 with the tracking position error signal Et having the positive polarity.
It is switched depending on whether it is given to or opposite polarity.

The mirror section detection circuit 8 monitors the amount of reflected light from the optical disk medium, detects whether or not the condensed beam is approaching the mirror section 1c, and outputs it to the polarity control circuit 9. Switch the selection signal. The polarity control circuit 9 inverts the polarity of the tracking position error signal Et based on this selection signal. When the focused beam travels on the land 1a and reaches the mirror portion 1c, the mirror portion 1c is actually detected when it passes through the end of the land 1a and is positioned on the mirror portion 1c.

However, the focused beam is reflected by the mirror section 1c.
If it is above, the tracking position error signal Et is not detected. Therefore, even when the polarity switching timing is slightly shifted, a large acceleration is not applied in the radial direction. When the focused beam exits from the mirror section 1c, it is positioned on the groove 1b, so that the tracking can be continued smoothly. During one revolution of the optical disk medium 1, the focused beam moves between the land 1a and the groove 1b without a track jump.

Next, the operation of this embodiment thus constructed will be described with reference to FIGS. 1 and 2. Figure 2
FIG. 2 is a configuration diagram showing a detailed circuit of FIG. 1.

The optical head 2 includes a laser diode 21 for emitting a light beam, an optical system including a collimator lens 22, a condenser lens 23, a beam splitter 24, and a cylindrical lens 25, an error signal detector 26, and a reproduction signal detector. Two
7 and a voice coil motor 28 which is a drive source of the condenser lens 23. The light beam emitted from the laser diode 21 passes through the optical system of the collimator lens 22, the condenser lens 23 and the beam splitter 24 and is condensed on the optical disc medium 1. Then, the reflected light is split by the beam splitter 24, passes through the condenser lens 23 and the cylindrical lens 25, respectively, and enters the reproduction signal detector 27 and the error signal detector 26. These optical systems are configured in the same manner as the conventional system, and use an astigmatism method as a focus error detection and a push-pull method as a track position error signal detection by a plurality of photodetectors on the error signal detector 26. And the required signal is extracted.

Next, the focus error detection circuit 4 amplifies the signal obtained from the error signal detector 26 by the preamplifier 41, and the error calculation circuit 42 calculates the focus proportional to the position error from the sum and difference of the plurality of detection signals. The position error signal Ef is output. Then, the focus servo circuit 7 applies the phase compensation by the phase compensation circuit 71, and then the driver 72 feeds back the voice coil motor 28 for the focus positioning of the condenser lens 23.

Similarly, the tracking error detection circuit 3 is
The signal obtained from the error signal detector 26 is supplied to the preamplifier 31.
And the tracking error calculation circuit 32 outputs a tracking position error signal Et corresponding to the track position error. Then, the tracking servo circuit 6 applies feedback to the voice coil motor 28 for track positioning of the condenser lens 23 by the driver 62 after performing phase compensation by the phase compensation circuit 61.

The polarity control circuit 9 receives the tracking position error signal Et as input and selects and outputs either the input signal itself or a signal whose polarity is inverted by the polarity inversion circuit 91. When tracking is performed on the land 1a of the optical disk medium 1, the error signal having the positive polarity is selected by the selector 92. The tracking switching between the land 1a and the groove 1b can be realized by controlling the polarity of the tracking position error signal given to the tracking servo circuit 6. Further, when tracking is performed on the groove, the tracking position error signal Et having the opposite polarity is selected. The switching of these polarities is performed by the mirror section detection circuit 8.

The mirror detection circuit 8 includes the error signal detector 2
The total amount of light incident on the optical disc 6 is monitored, and the reflected light from the mirror portion 1c of the optical disc medium 1 is the land 1a.
The number is larger than that in a region where a groove is formed, such as a groove 1b. Therefore, in the mirror unit arithmetic circuit 82, based on the signal from the error signal detector 26 amplified by the preamplifier 81, the mirror unit 1 is set as a region where the light amount exceeds a certain value.
c is detected. This mirror portion detection signal is input to the track selection circuit 83, and the polarity selection designation sent to the polarity control circuit 9 is switched at the leading edge of the mirror portion detection signal.

By adopting such a configuration, the focused beam which reaches the mirror portion 1c while tracking on the land 1a is switched to the servo polarity which becomes stable on the groove 1b, and the mirror portion 1c is switched. proceed. When it reaches the groove 1b after passing through the mirror portion 1c, a large acceleration is not applied,
Tracking can be continued stably.

The recording / reproducing circuit 5 amplifies a reproduction signal from a data processing circuit 53 for recording / reproducing data, a driver 51 for supplying power to the laser diode 21 at the time of recording data, and a reproduction signal detector 27. And a preamplifier 52. The recording / reproducing circuit 5 can perform data processing regardless of whether the focused beam is tracking on the land 1a or the groove 1b. Further, even if data is recorded / reproduced while the focused beam is moving between the land 1a and the groove 1b, a large acceleration is not applied to the optical head 2 and the adverse effect is small.

However, the signal quality at the mirror section 1c is as follows:
Since there is a difference in signal quality between the land 1a and the groove 1b, the mirror detection signal is given to the data processing circuit 53,
It is also conceivable to perform processing different from the usual processing. For example, only a signal of a specific frequency may be recorded in the mirror section 1c, and recording / reproducing of data may be performed only on the land 1a or the groove 1b. Also in this case, as compared with the case of moving between tracks by the jump operation, the tracking continues smoothly, so that the period in which data recording / reproduction is impossible can be shortened. Further, the signal recorded in the mirror section 1c can be effectively used for shortening the data synchronization recovery time. Further, an address signal having a relatively low recording frequency can be recorded on the mirror section. Since the address signal needs to be detected immediately after access, a detection method different from that of data is often provided, and there are few restrictions on recording density and the like.

There is also an advantage that the detection of the mirror section 1c can be used together with the detection of the address area. Further, even if the same address information is given to the adjacent land 1a and groove 1b, they can be distinguished by the tracking polarity,
The detection error of address information can also be reduced.

FIG. 3 is a block diagram showing an embodiment relating to the second and fourth inventions.

In the present embodiment, as shown in FIG. 3, only one mirror section 20c is provided from the center of the optical disk medium 20.
The lands 20a and the grooves 20b are alternately formed at an angle of 240 degrees. Then, the detection signal of the mirror unit 20c detected by the mirror unit detection circuit 8 is converted by the timing reproduction circuit 10 into a signal having a cycle of 1/3. Therefore, smooth tracking can be realized by switching the polarity of the tracking position error signal Et in synchronization with the output signal of the timing reproduction circuit 10. Also,
The operations of the tracking servo circuit 6, the focus error detection circuit 4 of the focus system 4, the focus servo circuit 7, and the recording / reproducing circuit 5 are realized in the same manner as in the conventional example.

In the optical disk medium 20 shown here, 1
The mirror portion 20c is not provided in the switching region between the land 20a and the groove 20b except for the portion. As a result, there is an advantage that there is little change in signal quality even in the switching area and a large data area can be effectively used. On the other hand, if the timing at which the polarity of the tracking position error signal Et is switched is deviated, the tracking becomes unstable because the servo information in the opposite direction is temporarily given.

However, such a switching timing deviation can be absorbed by providing a transition period in which the tracking position error signal Et is forcibly set to "0" before and after the polarity switching. This can be easily realized by configuring the circuit so that the polarity control circuit 9a outputs a signal corresponding to the tracking position error "0" during the transition period designated by the timing reproduction circuit 10.

In the above embodiment, the number of radial mirror portions or land / groove switching regions is three, but if these are odd numbers, the same effect can always be expected. Further, when a relatively large number of mirror portions are provided, the intervals can be used for data synchronization detection. Further, the detection period of the mirror portion can be used for controlling the rotation speed of the optical disc medium.

[0037]

As described above, according to the present invention, it is possible to continuously scan the entire optical disc medium while recording / reproducing data, without causing a period in which recording / reproducing of data is impossible. The data area can also be effectively used.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment related to first and third inventions.

FIG. 2 is a configuration diagram showing details of FIG.

FIG. 3 is a diagram showing an embodiment relating to second and fourth inventions.

FIG. 4 is a configuration diagram for explaining a conventional technique.

FIG. 5 is a diagram for explaining a track position error signal.

FIG. 6 is a diagram for explaining tracking according to a conventional technique.

[Explanation of symbols]

 1, 20, 30, 40, 41 Optical disk medium 1a, 20a, 30a, 40a, 41a Land 1b, 20b, 30b, 40b, 41b Groove 1c, 20c Mirror section 2,12 Optical head 3,13 Tracking error detection circuit 4, 14 focus error detection circuit 5,15 recording / reproducing circuit 6,16 tracking servo circuit 7,17 focus servo circuit 8 mirror detection circuit 9, 9a, 19 polarity control circuit 10 timing reproducing circuit 21 laser diode 22 collimator lens 23 condensing lens 24 Beam Splitter 25 Cylindrical Lens 26 Error Signal Detector 27 Playback Signal Detector 28 Voice Coil Motor 31, 41, 52, 81 Preamplifier 32 Tracking Error Calculation Circuit 42 Focus Error Calculation Circuit 51, 62, 72 Driver 53 Data Processing circuit 61, 71 a phase compensation circuit 82 mirror unit arithmetic circuit 83 track selection circuit 91 the polarity inverting circuit 92 selector Ef focus position error signal Et tracking position error signal

Claims (4)

[Claims] 1. An optical disk medium, wherein an odd number of mirror portions are provided radially from the center of the optical disk medium, and grooves are formed so that lands and grooves are alternated before and after the mirror portions. 2. A land is provided at least one mirror section radially from the center of the optical disk medium, and the land is formed at an angle obtained by equally dividing the circumferential direction by (2n + 1) (where n is a positive integer) with respect to the mirror section. An optical disk medium, wherein grooves are formed so that the grooves and the grooves are alternately replaced. 3. The optical disk medium according to claim 1,
A recording / reproducing method characterized by detecting whether or not a recording / reproducing beam is present on the mirror section, and switching the polarity of the tracking servo when the recording / reproducing beam is present on the mirror section. 4. The optical disk medium according to claim 2,
It is detected whether or not the recording / reproducing beam is present on the mirror portion, and when the recording / reproducing beam is present on the mirror portion, the rotation cycle reproduced from the mirror portion detection signal is (2n + 1) or the like. A recording / reproducing method characterized in that the polarity of the tracking servo is switched at each timing divided into minutes.