JP2003132551A - Optical recording medium, and optical information recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical recording medium which can be easily manufactured and at the same time even if an inter layer jump is found in the recording layer, and can immediately start the reproduction of information data from a data recording layer in a jumped area, and to provide an optical information recording and reproducing device. SOLUTION: The optical recording medium is constituted by laminating data recording layers on which information data are to be recorded, and a control mark layer is formed on which a control mark each carrying a synchronous clock to be a synchronization reference at recording this information data and a disk address indicating a location on the disk. The optical information recording and reproducing device makes a laser beam for reading or for recording transmit the data recording layer of the above optical recording medium, and simultaneously irradiates each of the data recording layer and the control mark layer. Consequently the recording or reproducing process of the information data to the data recording layer is executed based on the synchronous clock and the disk address while reading the synchronous clock and the disk address respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for recording / reproducing information data on / from an optical recording medium.

[0002]

2. Description of the Related Art At present, an optical disc having a plurality of data recording layers for recording information data in one disc is known as an optical recording medium. For example, in each data recording layer, a convex groove track on which an information mark for carrying information data is to be formed and a concave land track are alternately wobbled in a spiral or concentric shape. The surface of the groove track is coated with a recording material on which the information mark is formed by irradiation with laser beam light. Alternatively, in each data recording layer, address pits indicating positions on the disc in the data recording layer are discretely formed in advance.

To record or reproduce information data on such an optical disc, the wobbling state of the address pits or groove tracks is read,
Based on this, the recording or reproducing process is performed while recognizing the address on the disc. At the time of reproduction, a clock signal is generated from the read signal obtained by reading the information mark, and a PLL circuit or the like generates a synchronous clock signal of a predetermined frequency that is phase-locked with the clock signal. Then, the information data is restored by subjecting the read signal to demodulation processing synchronized with the synchronous clock signal. At this time, during a reproducing operation, a recording layer jump may be performed to change the data recording layer to be reproduced from one data recording layer to another data recording layer.

However, since the continuity of the synchronous clock signal is not maintained between the data recording layers, if the recording layer jump as described above is performed during the reproducing operation, the PLL is stopped.
It takes time for the circuit to lock to the new sync clock signal. During this time, the information data is not reproduced from the jump destination data recording layer, which causes a problem that it takes time to start the reproduction.

Further, in the above-mentioned optical disc, since the surface of the data recording layer becomes uneven due to the grooves and address pits, it is difficult to uniformly apply the recording material to the entire surface of the disc. Further, when the address pits are arranged in the data area, the usable area in the data area is reduced.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to easily manufacture the data recording layer and to jump quickly to the data recording layer even if a recording layer jump is made. It is an object of the present invention to provide an optical recording medium and an optical information recording / reproducing apparatus capable of starting reproduction of information data from the.

[0007]

An optical recording medium according to the present invention is an optical recording medium in which information data is recorded or reproduced by light irradiation, and at least one of the information data is to be recorded. A data recording layer and a control mark layer formed by arranging a plurality of control marks for carrying a synchronization clock signal, which serves as a synchronization reference when recording the information data, are stacked.

Further, the optical information recording / reproducing apparatus according to the present invention is an optical system in which at least one data recording layer and a control mark layer in which a plurality of control marks for synchronizing clocks are arranged in series are laminated. An optical information recording / reproducing apparatus for recording / reproducing information data on / from a recording medium, wherein the optical axes of a first laser beam and a second laser beam having different focusing positions are made to coincide with each other, and the data recording is performed. Means for simultaneously irradiating the layer and the control mark layer,
Means for reproducing the synchronous clock based on an electric signal obtained by photoelectrically converting the reflected light from the control mark layer by the second laser beam, and the reflected light from the data recording layer by the first laser beam Means for photoelectrically converting the read signal to obtain a read signal, and means for reproducing the information data recorded in the data recording layer by performing demodulation processing on the read signal at a timing according to the synchronous clock, A means for performing a recording modulation process on information data to be recorded on the optical recording medium at a timing according to the synchronous clock to obtain a modulated recording signal, and a laser beam having an optical power according to the modulation recording signal. Means for generating the first laser beam.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a diagram showing an example of a sectional structure of an optical disc as an optical recording medium according to the present invention. The optical disc includes a transparent cover layer 21, three data recording layers 22a to 22c, a transparent spacer layer 23, and a disc substrate 25 having a control reflection surface 24. The transparent cover layer 21 becomes an incident surface of the laser beam light emitted from the recording / reproducing head described later. Data recording layers 22a-2
Each of 2c has an information mark formed thereon, which carries information data when irradiated with a recording laser beam, for example, phase change recording made of Ag, In, Sb, Te (silver, indium, antimony, tellurium). Material has been applied. Each of these data recording layers 22a to 22c is a transparent spacer layer 2
3 are formed so as to be separated from each other. Further, control pits Pc are formed on the control reflection surface 24 of the disk substrate 25.

FIG. 2 is a diagram showing an example of the arrangement of the control pits Pc viewed from the laser beam light incident surface side.
As shown in FIG. 2, on the control reflection surface 24, a plurality of control pits Pc each having a predetermined fixed length L are separated from each other by a predetermined constant distance d, and are concentric circles as shown by broken lines. Alternatively, it is formed so as to meander in a line along a spiral track. At this time, the meandering form of the pit string of the plurality of control pits Pc in a predetermined unit length corresponds to the disc address indicating the position on the disc.
That is, each control pit Pc is formed at a position displaced in the disc radial direction with respect to the track indicated by the broken line by an amount corresponding to a modulation signal obtained by phase-modulating a sine wave of a predetermined frequency by the disc address. -ing The pit string formed by the control pits Pc bears the above-mentioned disc address and, as will be described later, tracking error information and information data are recorded in the data recording layer 22a.
It also plays a role of a synchronization clock that serves as a synchronization reference when recording on the recording mediums 22 to 22c.

FIG. 3 is a view showing the arrangement of an optical information recording / reproducing apparatus for recording or reproducing information data on such an optical disc. In FIG. 3, the recording modulation circuit 31
Is an optical disk 20 having a structure as shown in FIG.
The information data to be recorded on the 0 data recording layer 22a, 22b or 22c is subjected to modulation processing according to a desired recording modulation method. At this time, the recording modulation circuit 31 performs a recording modulation process on the information data in synchronization with a timing according to a synchronization clock signal CK (described later), and supplies the obtained modulated recording signal to the light source driver 32. . The light source driver 32, when recording operation of the optical information recording / reproducing apparatus,
A light source drive signal having a signal level corresponding to the modulated recording signal is generated and supplied to a recording / reproducing head 100 mounted on a slider mechanism (not shown). On the other hand, during the reproducing operation of the optical information recording / reproducing apparatus, the light source driver 32 generates a light source drive signal having a predetermined fixed level and supplies it to the recording / reproducing head 100. The slider mechanism moves the recording / reproducing head 100 in the disc radial direction of the optical disc 200 in response to a tracking error signal TE described later or a drive signal supplied from the recording / reproducing controller 40.

The first light source 11 of the recording / reproducing head 100 is
The laser beam light having the optical power corresponding to the light source drive signal supplied from the light source driver 32 is generated. That is, the first light source 11 causes the data recording layer 22 of the optical disc 200 during the reproducing operation of the optical information recording / reproducing apparatus.
A reading laser beam having an optical power required to read the recording mark formed on a, 22b, or 22c is generated. On the other hand, during the recording operation, the first light source 11
In response to the modulated recording signal, the data recording layer 22a,
A recording laser beam light having an optical power required to form a recording mark on 22b or 22c is generated. Then, the first light source 11 irradiates the synthesizing prism 13 with the recording laser beam light or the reading laser beam light (hereinafter referred to as the first laser beam).

The second light source 12 generates a laser beam light (hereinafter referred to as a second laser beam) to be irradiated on the control reflection surface 24 of the optical disc 200, and this is used as the synthetic prism 1.
Irradiate 3. The combining prism 13 is the first light source 11
Is generated and the second laser beam generated by the second light source 12 are combined by aligning their optical axes and supplied to the collimator lens 15 via the beam splitter 14. The collimator lens 15 converts the laser beam combined as described above into substantially parallel light, and supplies this to the objective lens 16. The objective lens 16 collects the substantially parallel light and irradiates the transparent cover layer 21 of the optical disc 200 which is rotated by a spindle motor (not shown). At this time, the optical path length from the second light source 12 to the collimator lens 15 is shorter than the optical path length from the first light source 11 to the collimator lens 15. That is, the second
When the second laser beam emitted from the light source 12 is focused on the control reflection surface 24 of the optical disc 200, the first light source 11
The optical path lengths of the two are set so that the first laser beam emitted from the laser beam is focused near the data recording layer 22a, 22b, or 22c of the optical disc 200.

The laser beam is emitted from the optical disc 200.
The reflected light when it is irradiated onto the laser beam is guided to the beam splitter 112 via the objective lens 16, the collimator lens 15, and the condenser lens 111. Beam splitter 112
Transmits a reflected light component based on the first laser beam in the reflected light and guides it to the first photodetector 113. Further, the beam splitter 112 transmits the reflected light component based on the second laser beam in the reflected light and guides it to the second photodetector 114. That is, the beam splitter 112 serves as the data recording layer 2 of the optical disc 200.
The reflected light component from the control reflection surface 24 of the optical disc 200 is guided to the second photodetector 114 while the reflected light component from 2 is guided to the first photodetector 113. On this occasion,
Astigmatism is given to the reflected light component by the beam splitter 112.

The first photodetector 113 is the optical disc 200.
The light reflected from the data recording layer 22a, 22b, or 22c of the four optical detection surfaces Fa arranged as shown in FIG.
Light is received at ~ Fd. Then, the first photodetector 113 is
Electrical signals obtained by photoelectrically converting the reflected lights received by the light detection surfaces Fa to Fd individually are read signals RFa to.
It is supplied as RRFd to each of the information data demodulation circuit 33 and the focus error generation circuit 34.

The information data demodulation circuit 33 performs a predetermined demodulation process at a timing corresponding to a synchronous clock signal CK (described later) based on the added read signal obtained by adding the read signals RFa to RFd. By such demodulation processing,
The information data demodulation circuit 33 includes the data recording layer 22a,
The information data recorded in 22b or 22c is restored, and this is output as reproduction information data.

The focus error generating circuit 34 is shown in FIG.
Among the light detection surfaces Fa to Fd as shown in (a), the output sums of the light detection surfaces diagonally arranged to each other are obtained, and the difference value between the two is supplied to the focusing actuator 115 as a focus error signal FE. . That is, the focus error generation circuit 34 obtains the focus error signal FE by the following calculation using the read signals RFa to RFd based on the reflected light from the data recording layer 22a, 22b, or 22c of the optical disc 200, and the focusing actuator 115. Supply to.

FE = (RFa + RFc) − (RFb + RFd) The focusing actuator 115 moves the objective lens 16 in the vertical direction of the optical disc 200, that is, on a so-called focus adjustment trajectory according to the focus error signal FE. As a result, the first laser beam emitted from the first light source 11 is emitted from the optical disc 2
Focusing control for condensing on the data recording layer 22a, 22b, or 22c of No. 00 is performed. According to such focusing control, the first laser beam causes the data recording layer 22a, 22b, or 22c of the optical disc 200 to be recorded.
The second laser beam emitted from the second light source 12 is focused on the upper surface of the data recording layer 2 on the control reflection surface 24.
Focusing will be performed within the distance range of 2a, 22b, or 22c.

The second photodetector 114 is the optical disc 200.
The reflected light from the control reflection surface 24 is received by the four light detection surfaces Fa to Fd arranged as shown in FIG. 4 (b). The second photodetector 114 uses the electric signals obtained by individually photoelectrically converting the reflected lights received by these photodetection surfaces Fa to Fd as read signals Ra to Rd, and push-pull signal generation circuit 3
5 and the clock signal generation circuit 38.

The push-pull signal generation circuit 35 generates a push-pull signal PP by the following calculation using each of the read signals Ra to Rd output from the second photodetector 114, and outputs the push-pull signal PP to the tracking error generation circuit 36 and the address. It is supplied to each of the demodulation circuits 37. PP = (Ra + Rd)-(Rb + Rc) The tracking error generation circuit 36 extracts the low frequency component of the push-pull signal PP, and uses it as the tracking error signal TE.
Supply to. That is, the tracking error generation circuit 3
6 generates the tracking error signal TE based on the read signals Ra to Rd obtained when the control pits Pc formed on the control reflection surface 24 of the optical disc 200 as shown in FIG. 2 are read. The tracking actuator 116 receives the tracking error signal TE.
The optical axis of the objective lens 16 is swung in the radial direction of the disk by an amount corresponding to. As a result, the second laser beam emitted from the second light source 12 is controlled by the control reflection surface 2 of the optical disc 200.
Tracking control is performed so as to follow on the track of No. 4 (shown by the broken line in FIG. 2).

The address demodulation circuit 37 demodulates an address representing a position on the disc by subjecting the push-pull signal PP to a predetermined phase demodulation process, and uses this as a disc address AD for the recording / reproducing controller 40.
Supply to. The recording / reproducing controller 40 carries out various recording operations and reproducing operations of the optical information recording / reproducing apparatus in response to various operations from the user, so that the recording modulating circuit 31, the light source driver 32, and the information data demodulating circuit 3 are performed.
3. Control the recording / reproducing head 100, the spindle motor and the slider mechanism. At this time, during the recording operation, the recording / reproducing controller 40 causes the data recording layers 22a, 22b,
Alternatively, in order to start recording from the head position of the unrecorded area in 22c, the head position is searched based on the disk address AD. Further, during the reproducing operation, the recording / reproducing controller 40 obtains the reproduction elapsed time, the remaining time, etc. by referring to the disc address AD and displays them on a display unit (not shown).

The clock signal generating circuit 38 calculates the signal level representing each control pit Pc formed on the control reflection surface 24 of the optical disc 200 from the added read signal obtained by adding the above read signals Ra to Rd, as shown in FIG. A clock pulse is generated each time it is detected. Then, the clock signal generation circuit 38 generates a clock signal of a predetermined frequency that is phase-synchronized with the pulse train of this clock pulse, and supplies this to the recording modulation circuit 31 and the information data demodulation circuit 33 as the synchronous clock signal CK. To do. At this time, if the cycle of the clock pulse generated according to the reading of the control pit Pc is longer than the cycle of the synchronous clock signal CK, a relatively inexpensive long wavelength laser light source can be used as the second light source 12. .

Next, recording and reproducing operations by the optical information recording / reproducing apparatus will be described. When a recording or reproduction start command is issued from the recording / reproduction controller 40, the objective lens 16 of the recording / reproduction head 100 causes the second laser beam, which is responsible for reading various control information together with the first laser beam, to be the control reflection surface 24 of the optical disc 200. Focusing control is performed so as to focus substantially on the top. Furthermore, the objective lens 16
Is tracking-controlled so that the second laser beam traces on the track (shown by the broken line in FIG. 2) of the control reflection surface 24 of the optical disc 200. As a result, the first laser beam for recording or reading the information data is tracking-controlled so that its beam extension axis traces the track of the control reflection surface 24, and the data recording layers 22a, 22b, Or, focus on 22c. Therefore, during the recording operation, an information mark carrying information data is formed on the data recording layer 22a, 22b, or 22c according to the tracking control. On the other hand, during the reproducing operation, the information mark recorded on the data recording layer 22a, 22b, or 22c is read according to the tracking control. At this time, the synchronous clock signal CK is obtained by reading the control pits Pc formed on the control reflection surface 24 along the track as shown in FIG. Furthermore, based on the meandering form of the pit row by the control pits Pc,
A disc address AD representing a position on the disc is acquired. Then, various recording or reproducing processes are executed based on the synchronous clock signal CK and the disc address AD read from the control reflection surface 24. At this time, even if any of the data recording layers 22a, 22b, or 22c is the reproduction target (or the recording target), the tracking error signal, the synchronization clock signal, and the disc address acquired from the control reflection surface 24 are obtained. Based on the above, the recording or reproducing process as described above is performed. That is, various control information acquired from the control reflection surface 24 is stored in the data recording layer 22.
It is commonly used during the recording process (or reproduction process) for each of a, 22b, and 22c.

Thus, the optical disc 200 according to the present invention
In addition to the data recording layer 22 on which the information data is recorded, a control pit Pc which carries each of a synchronization clock signal CK serving as a synchronization reference when recording this information data and a disc address AD indicating a position on the disc is formed. It is provided with the formed control mark layer (control reflective surface 24 and disk substrate 25). Further, in the optical information recording / reproducing apparatus according to the present invention, the laser beam is simultaneously applied to both the data recording layer 22 and the control reflection surface 24 by transmitting the data recording layer 22. Thereby, while the synchronous clock signal CK and the disc address AD are respectively acquired from the control reflection surface 24, the recording or reproducing process of the information data with respect to the data recording layer 22 is executed based on the acquired synchronous clock signal CK and the disc address AD. I am trying to do it.

Therefore, according to the present invention, the phase of the synchronization clock is maintained even when the recording layer jump is made during the reproducing operation, so that the information data is immediately recorded or reproduced from the jumped data recording layer. It is possible to start the operation. Furthermore, since it is not necessary to form pits that carry the synchronization clock and the disk address in the data recording layer, it is possible to uniformly apply the recording material to the surface of the data recording layer 22.

In the above embodiment, the first light source 11 for generating the first laser beam for recording or reading on the data recording layer 22 and the second laser beam for reading from the control reflection surface 24 are used. Although the second light source 12 for generating the light source is provided separately, the number of the light source itself may be one. For example, the second light source 12 shown in FIG. 1 is omitted, and a hologram element is used instead of the combining prism 13. Due to the action of the hologram element, the focal point of the laser beam emitted from the first light source 11 can be on both the data recording layer 22 and the control reflection surface 24 of the optical disc 200. During the recording operation,
Since the laser beam emitted from the first light source 11 is modulated by the information data, the control pit Pc cannot be read well from the control reflection surface 24 as it is. Therefore, a front monitor element (not shown) that detects the leaked light of the laser beam emitted from the first light source 11 is provided near the first light source 11. Then, based on the level of leaked light detected by the front monitor element, the recording modulation component is canceled from the read signals Ra to Rd output by the second photodetector 114. This allows
The control pits Pc are satisfactorily read from the control reflection surface 24, and various control information such as a tracking error signal, a focusing error signal, a synchronizing clock and a disk address can be acquired.

Further, in the above embodiment, the control reflection surface 2
The disc address AD indicating the position on the disc in which the control pit Pc is formed is obtained based on the meandering form of the pit row by the plurality of control pits Pc formed in No. 4, but is not limited to this. Not a thing. For example, the disc address AD indicating the position on the disc where the control pit Pc is formed may be acquired based on the pit length of the control pit Pc. On this occasion,
The pit length of the control pit Pc is multiplied in accordance with the change of the disk address so that the synchronous clock signal CK can be acquired well even if the pit length of the control pit Pc changes.

In the above embodiment, Ag and I are used as the recording materials applied to the data recording layers 22a to 22c.
Although a phase change recording material made of n, Sb, Te (silver, indium, antimony, tellurium) is used, an organic dye recording material or a magneto-optical recording material may be used. Further, in the above embodiment, the optical disc 200 is used as the optical recording medium, but the shape of the medium is not limited to the disc shape, and for example, a rectangular shape as shown in FIG. It may be an optical card. Also in such an optical card, as in the optical disc 200, the transparent cover layer 2
1, data recording layers 22a to 22c, and control reflection surface 24
It is comprised from the board | substrate 25 provided with. A plurality of control pits Pc are formed on the control reflection surface 24 of the optical card in a form as shown in FIG. 5B, meandering along the tracks shown by the broken lines.

Further, the optical disk 20 shown in the above embodiment.
0 (or optical card) has three data recording layers 22a to 22c in one disk (or card), but the number of data recording layers provided in one medium is four or more, or a single layer. May be Further, in the embodiment, a concave control pit Pc is adopted as a control mark to be recorded on the control reflection surface 24 so as to carry each of the synchronous clock signal CK and the disc address AD, but the shape of this control mark is The shape is not limited to the concave shape. in short,
The control mark is not limited to a convex or concave pit, and in the case of phase change recording, for example, any one of the mark and the space may be represented.

[0030]

As described in detail above, the optical recording medium according to the present invention has a data recording layer on which information data is to be recorded, a synchronization clock serving as a synchronization reference when recording the information data, and an on-disk. A control mark layer on which control marks each bearing a disc address indicating a position are formed is laminated. Further, in the optical information recording / reproducing apparatus according to the present invention, a laser beam for reading or recording is transmitted through the data recording layer of the optical recording medium and is simultaneously irradiated to each of the data recording layer and the control mark layer. Thus, while reading each of the synchronization clock and the disc address from the control mark layer, the recording or reproducing process of the information data with respect to the data recording layer is executed based on the synchronization clock and the disc address.

Therefore, according to the present invention, the phase of the synchronization clock is maintained even when the recording layer jump is made during the reproducing operation, so that the information data is immediately recorded or reproduced from the jumped data recording layer. It is possible to start the operation. Furthermore, since it is not necessary to form pits that carry the synchronization clock and the disk address in the data recording layer, it becomes possible to apply the recording material uniformly to the surface of the data recording layer, and the manufacture of the optical recording medium becomes easy. .

[Brief description of drawings]

FIG. 1 is a diagram showing a cross-sectional structure of an optical disc according to the present invention.

2 is a diagram showing an example of an array form of control pits Pc formed on a control reflection surface 24 of the optical disc shown in FIG.

FIG. 3 is a diagram showing a configuration of an optical information recording / reproducing apparatus according to the present invention.

FIG. 4 is a diagram showing light receiving surfaces of a first photodetector 113 and a second photodetector 114.

FIG. 5 is a view showing the structure of an optical card according to another embodiment of the present invention.

[Explanation of symbols for main parts]

11 First light source 12 Second light source 13 Synthetic prism 16 Objective lens 24 Control reflective surface 37 Address demodulation circuit 38 Clock signal generation circuit 114 second photodetector 200 optical disks

Claims (10)

[Claims] 1. An optical recording medium in which information data is recorded or reproduced by light irradiation, wherein at least one data recording layer in which the information data is to be recorded, and at the time of recording the information data An optical recording medium, comprising: a control mark layer, which is formed by arranging a plurality of control marks that carry a synchronization clock signal serving as a synchronization reference in series, and is stacked. 2. The optical recording medium according to claim 1, wherein the control mark also carries address information indicating a position on the optical recording medium. 3. The optical recording medium according to claim 1, wherein the control marks have the same length. 4. The optical recording medium according to claim 1, wherein each of the control marks is arranged in a meandering manner. 5. The optical recording medium according to claim 1, wherein each of the control marks is arranged in a meandering shape corresponding to the address. 6. The optical recording medium according to claim 1, wherein the optical recording medium is disk-shaped, and the control marks are arranged in a spiral or concentric manner. 7. The optical recording medium according to claim 1, wherein each of the control marks has a pit shape. 8. The optical recording medium according to claim 1, wherein the control mark is formed only on the control mark layer of the data recording layer and the control mark layer. 9. Recording or reproducing of information data to or from an optical recording medium in which at least one data recording layer and a control mark layer in which a plurality of control marks for carrying a synchronous clock are arranged in series are laminated. An optical information recording / reproducing apparatus for performing the above, wherein the optical axes of the first laser beam and the second laser beam having different focusing positions are made to coincide with each other, and the data recording layer and the control mark layer are irradiated simultaneously. Means for reproducing the synchronous clock based on an electric signal obtained by photoelectrically converting the reflected light from the control mark layer by the second laser beam, and the means for reproducing the synchronous clock from the data recording layer by the first laser beam. Means for photoelectrically converting the reflected light to obtain a read signal; and a means for demodulating the read signal at a timing according to the synchronous clock. Means for reproducing the information data recorded in the optical recording layer, and recording modulation processing for the information data to be recorded in the optical recording medium at a timing according to the synchronous clock to obtain a modulated recording signal. An optical information recording / reproducing apparatus comprising: a means and a means for generating a laser beam having an optical power corresponding to the modulated recording signal as the first laser beam. 10. The control mark also carries address information indicating a position on the optical recording medium, and is obtained by photoelectrically converting light reflected from the control mark layer by the second laser beam. The optical information recording / reproducing apparatus according to claim 9, further comprising means for reproducing the address information based on an electric signal.