JPH08315446A - Optical information recording medium and optical information recording and reproducing device - Google Patents

Abstract

PURPOSE: To obtain an optical information recording means capable of simultaneously or in time division reproducing addresses and data by increasing the capacity of the addresses, single amplitude and data capacity. CONSTITUTION: The optical information recording medium 7 is provided thereon with a recording layer 12 for recording or reproducing address information and a recording layer 10 for recording or reproducing data information independently of each other. The address signals of sufficient signal amplitudes are obtd. by this constitution even if a track pitch is narrowed. The sure reproduction is thus executed and the memory capacity is greatly improved.

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 medium and an optical information recording device.

[0002]

2. Description of the Related Art Conventionally, CD-R (Compact Disk Reco)
rdable) and MD (Mini Disk) "Development of Mini Disc System" polyfile, 93, 5, p.34 to 36, optical disc media (optical information recording media), the absolute address on the disc surface (or In order to display (absolute time), the address (or time) information is FM-modulated, and the track groove is slightly meandered in accordance with the modulation.

FIG. 7 shows an example of the structure of a recordable optical disc 1. A recording layer 3 is formed on a substrate 2, and a track groove composed of a land 4 and a groove 5 is formed on the surface of the recording layer 3. L is called a track pitch and represents a track width. The groove 5 is formed to meander to show an absolute address.

Information is recorded on the optical disc 1 by recording a recording pit (recording mark) 5a by converging a light beam from the focus-controlled objective lens 6 on the groove 5. Information is reproduced by detecting the reflected light from the region of the meandering groove 5 in which the recording pit 5a is recorded.

[0005]

An FM signal corresponding to the meandering of the groove 5 is superimposed on the track error signal detected when the information is reproduced by using the reflected light from the optical disk 1. The address on the optical disc 1 can be known by extracting this FM signal using a bandpass filter or the like. The amplitude of the FM signal superimposed on such a track error signal increases as the degree of meandering of the groove 5 increases, which allows accurate signal detection.

In recent years, it has been desired to increase the capacity of the optical disc 1. As one means for increasing the recording capacity, there is a method of narrowing the track pitch L. However, in the case of the optical disc 1 in which the address information is obtained from the wobbling of the groove 5 as described above, the narrower the track pitch L is, the smaller the wobbling is limited, and the amplitude of the FM signal cannot be obtained sufficiently. As a result, it may not be possible to detect accurate address information.

[0007]

According to a first aspect of the invention, there is provided a first recording layer for recording or reproducing at least address information, and a second recording layer for recording or reproducing at least data information other than the address information. Was set up.

According to a second aspect of the invention, in the first aspect of the invention, the first recording layer in which the address information is recorded or reproduced is formed of a magneto-optical recording material.

According to the invention of claim 3, in the invention of claim 1, the second recording layer is formed of a rewritable recording material.

According to the invention of claim 4, claim 2 or 3
In the described invention, address information by magneto-optical recording is recorded in advance on the first recording layer.

According to a fifth aspect of the invention, in the second, third or fourth aspect of the invention, the second recording layer is formed on the side of the substrate on which the light beam is incident, and the first recording layer is located at a position distant from the substrate. Layers were formed.

According to a sixth aspect of the invention, in the invention of the second, third or fourth aspect, a light transmissive heat dissipation layer is provided between the first recording layer and the second recording layer.

According to the invention of claim 7, claims 1, 2,
Focus control means for converging a light beam in the area of the recording layer of the optical information recording medium described in 3, 4, 5 or 6, and address reproducing means for reproducing an address signal from a difference signal of reflected light from the optical information recording medium. And a data reproducing means for reproducing a data signal from a sum signal of reflected light from the optical information recording medium.

According to the invention of claim 8, in the invention of claim 1, between the first recording layer and the second recording layer,
A transparent substrate was provided.

According to a ninth aspect of the invention, in the eighth aspect of the invention, the first recording layer having an address formed by prepits is provided on the transparent substrate.

According to a tenth aspect of the invention, there is provided a focus control means for condensing the light beam on each recording layer of the optical information recording medium according to the eighth or ninth aspect, and the focus control means causes the first light beam to pass through the first light beam. Address detecting means for detecting the address signal from the reflected light by condensing on the recording layer, and moving the light beam focused on the first recording layer to the second recording layer based on the signal from the address detecting means. And a beam transfer means for controlling the beam.

According to an eleventh aspect of the present invention, focus control means for focusing the light beam on each recording layer of the optical information recording medium according to the eighth or ninth aspect and second recording of the light beam by the focus control means. Data recording means for collecting (focusing) on a layer to detect reflected light and reproducing a data signal, and first recording while focusing (focusing) a light beam on the second recording layer. An address reproducing means for detecting reflected light from the layer and reproducing an address signal is provided.

[0018]

According to the first aspect of the invention, the address information recording layer (first recording layer) for recording / reproducing the address information (which may include information for the synchronizing signal, etc.) and other than the address information By separately forming a data information recording layer (second recording layer) for recording and reproducing the data information, and reproducing each information from each of these recording layers, the same recording layer is formed as in the conventional case. Since neither information of address nor data is recorded, if the data capacity is prioritized, the address capacity and signal amplitude are limited, and conversely, if the address is prioritized, the data capacity is limited. It is possible to eliminate the phenomenon of OFF, which makes it possible to obtain address information with a sufficient amplitude even if the track pitch becomes narrow.

According to the second aspect of the present invention, the address information is recorded as a magneto-optical signal in the recording layer for address information, and the data information other than the address is recorded as a signal due to a change in light amount. It is possible to reproduce the signal and the signal of the light amount change (reflectance change) without interfering with each other.

According to the third aspect of the invention, when the address information recording layer is irradiated with a light beam to record the address, the recording layers for the data information other than the adjacent addresses are also recorded at the same time. Even in such a case, since the recording layer of the data information is rewritable, recording (rewriting) can be performed thereafter without any problem.

According to the invention of claim 4, the address information by magneto-optical recording is recorded in advance on the recording layer for address information before shipping, so that the user can save the time and effort of recording the address after shipping. it can.

In the fifth aspect of the invention, the recording / reproducing light beam is incident on the data information recording layer close to the substrate, and then is guided to the address information recording layer distant from the substrate. As a result, in particular, data information can be efficiently recorded on the recording layer.

According to the sixth aspect of the present invention, since the light transmissive heat dissipation layer is interposed between the recording layers, the magneto-optical film of the recording layer for address information is formed at the time of recording on the recording layer for data information. It can prevent being heated.

According to the invention of claim 7, a region of the address and data recording layer of the optical information recording medium is irradiated with a light beam, and the address reproduction means is used to change the address from the difference signal (magneto-optical signal) of the reflected light. By reproducing the signal and reproducing the data signal from the sum signal of the reflected light by using the data reproducing means, the detection of the address information and the reproduction of the data information can be simultaneously processed.

According to the invention described in claim 8, by providing a transparent so-called second substrate between the recording layer for address information and the recording layer for data information, the address information and the data information are It is possible to reliably detect the change in the amount of reflected light from each recording layer.

In the ninth aspect of the invention, since the address information is formed as pre-pits on the transparent recording layer on the second substrate, the desired information can be obtained by simple molding even when the track pitch is narrow. You can create an address.

In the tenth aspect of the invention, the focus control means is used to focus the light beam on the recording layer for address information, and the address detecting means is used to reflect the light beam from the recording layer for address information. After detecting the address signal by light, the light beam is moved from the recording layer for address information to the recording layer for data information by using the beam shifting means, and this time the reflected light from the recording layer for data information is reflected. This makes it possible to detect the data signal.

In the eleventh aspect of the invention, with the light beam being focused on the data information recording layer by using the focus control means, the data reproducing means is used to move the light beam from the recording layer for data information. When the reflected light is detected and the data signal is reproduced, the reflected light from the recording layer for address information is detected by the address reproducing means to reproduce the address signal, thereby reproducing the data information from the focused light beam. At the same time, address information can be detected from the defocused light beam.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1 to 3 (corresponding to the invention described in claims 1 to 7). The same reference numerals are used for the same parts as those in the conventional technique (see FIG. 7).

FIG. 1 shows an optical disk 7 (optical information recording medium).
The cross-sectional shape of is shown. A data layer 10 as a second recording layer is formed on a substrate (made of polycarbonate) 8 via a protective layer 9. The data layer 10 is composed of a phase change material. In addition, on the data layer 10,
An address layer 12 as a first recording layer is provided via a light transmissive heat dissipation layer 11. This address layer 12
Is made of a magneto-optical material, and a magneto-optical mark is recorded here as address information. A protective layer 13 and a protective layer 14 are sequentially stacked on the address layer 12. The protective layer 13 also serves as the reflective layer of the phase change type data layer 10 together with the address layer 12. The protective layer 14 is made of an ultraviolet curable resin. Thus, in the optical disc 7, the data layer 10 made of the phase change material is formed on the substrate 8 side, and the address layer 12 made of the magneto-optical material is formed at a position apart from the substrate 8. It is possible to record not only the address information but also the synchronization signal and the like (preformat information) on the address layer 12.

FIG. 2 shows the configuration of a signal detection optical system in a drive device (optical information recording / reproducing device) for recording / reproducing information on / from the optical disk 7. Objective lens 6 facing the optical disk 7 and focusing a light beam on the disk surface
Is arranged. The objective lens 6 is drive-controlled by a focus control means (not shown). A polarization beam splitter 15 is arranged on the optical path of the reflected light from the optical disc 7 obtained through the objective lens 6.
A light receiving element 16 is arranged on the optical path where the reflected light is reflected by the polarization beam splitter 15, and a light receiving element 17 is arranged on the optical path where the reflected light is transmitted. In addition, the light receiving element 16,
An amplifier 18 for obtaining the difference between the received light outputs and an amplifier 19 for obtaining the sum of the received light outputs are connected to 17. An address reproducing circuit 20 (address reproducing means) for reproducing an address signal from the difference signal of the received light output is connected to the amplifier 18. A data reproduction circuit 21 (data reproduction means) for reproducing a data signal from the sum signal of the received light output is connected to the amplifier 19.

In such a structure, the light beam emitted from the laser light source (not shown) is condensed by the objective lens 6 and enters from the substrate 8 side of the optical disk 7. As a result, the light beam reaches the data layer 10 and the phase change state changes, whereby a recording mark corresponding to the data information is formed, and thereby information is recorded on the optical disc 7. When reproducing information from the optical disk 7,
Similarly, when the light beam is incident from the substrate 8 side and is irradiated on the data layer 10, the recording mark changes the light intensity distribution of the reflected light, and the magneto-optical mark on the address layer 12 further changes the reflected light. The plane of polarization is rotated.

The reflected light whose light intensity distribution and polarization plane are changed in this way is divided into two by the polarization beam splitter 15 via the objective lens 6 in accordance with the rotation components (P, S polarization) of the polarization plane. And are guided to the light receiving elements 16 and 17, respectively. Then, the amplifier 18 causes the light receiving elements 16 and 17
The difference between the received light outputs of the two is obtained, and a magneto-optical signal is generated.
This magneto-optical signal is sent to the address reproducing circuit 20, whereby the address corresponding to the magneto-optical mark on the address layer 12 is reproduced. On the other hand, the light receiving element 1
The sum of the received light outputs of 6 and 17 is obtained, and the data signal is generated. This data signal is sent to the data reproducing circuit 21, and thereby the data corresponding to the recording mark of the data layer 10 is reproduced.

In this case, the data layer 10 gives strength to the reflected light but does not affect the polarization direction of the reflected light, so that the rotation direction of the reflected light itself does not change, whereby the polarity of the magneto-optical signal causes the data to disappear. An address signal independent of the signal can be accurately detected. Further, although the address layer 12 rotates in the polarization direction of the reflected light, but does not affect the reflected light amount, the data signal can be accurately reproduced by detecting the intensity of the reflected light amount. FIG.
Shows the waveform 22 of the detected data signal, the waveform 23 of the address signal when there is no recording mark, and the waveform 24 of the address signal modulated by the strength of the data signal. In this case, as can be seen from the waveform 24, although it is modulated to some extent in proportion to the strength of the waveform 22, it is understood that the polarity has not changed, and the address signal can be accurately detected. In this way, the address information and the data information can be reproduced simultaneously from the optical disc 7.

As described above, the optical disc 7 has the address layer 12 in which the address information is recorded and the data layer 10 in which the data information is recorded, which are formed separately from each other. Since both the information and the information are not formed in the same recording layer, the capacity of the address information and the signal amplitude are not limited, and the storage capacity can be expanded. Further, the data layer 10 is the address layer 10
Since the light beam is provided on the substrate 8 side more than the substrate 8 and the light beam at the time of recording first enters the data layer 10, the laser power at the time of recording can be efficiently used. Further, since the address layer 12 made of a magneto-optical material has a property of losing its magnetic field coercive force when the Curie temperature is reached by heating, the magnetization direction of the magneto-optical mark is reversed in the presence of an external magnetic field. May disappear, but
Since the heat dissipation layer 11 is provided between the address layer 12 and the data layer 10, at the same time as the quenching effect of the data layer 10 serving as a phase change layer, the heat at the time of recording of the data layer 10 is applied to the address layer 12 side. Therefore, the state of the recorded address can be maintained normally.

In this embodiment, it is premised that the address layer 12 has all the addresses recorded by the magneto-optical marks. However, when the drive device has a magnetic head and has a magneto-optical recording function. It is also possible for the user to write the address by himself / herself at the first stage of use.
In this case, the recording power of the light beam incident from the substrate 8 side requires a considerably large value, but the efficiency is improved by setting the incident direction of the light beam on the opposite side to the substrate 8 as shown in the direction A of FIG. You can write address information well. Further, the data layer 10 is a rewritable material (phase change,
In the case of the magneto-optical recording medium, it is possible to record only the address at the stage before shipping by recording from the direction A, which saves the user the trouble of address recording. When writing to the address layer 12, the data layer 1 is heated by a light beam.
Although an address may be recorded even at 0, there is no problem because the data layer 10 is made of a rewritable material and can be easily rewritten thereafter.

Next, a second embodiment of the present invention will be described based on FIGS. 4 and 5 (corresponding to the invention described in claims 8, 9, and 10). The same reference numerals are used for the same parts as those in the first embodiment.

FIG. 4 shows the sectional shape of the optical disk 25. A phase change data layer 10 is formed on a substrate (made of polycarbonate) 8 via a protective layer 9. A transparent substrate 26 is provided on the data layer 10. The substrate 26 is a so-called second substrate having a thickness (about 50 μm) which is about the manufacturing tolerance of the substrate 8 (first substrate). The material of the substrate 26 is made of photopolymer, and the substrate surface is an area for recording address information (area corresponding to the address layer 12). Pits 27 are formed on the surface of the substrate 26 as pre-pits indicating address information. The pits 27 are formed by a stamper after the substrate 26 is coated with an ultraviolet curable resin, and are cured by irradiation with ultraviolet rays.
Are located directly above the grooves 5 and are arranged along the groove forming direction. And such a pit 27
A reflective layer 28 and a protective layer 29 made of an ultraviolet curable resin are sequentially laminated on the substrate 26 on which is formed. Thus, in the optical disc 25, the data layer 10 is formed on the substrate 8 (first substrate) side, and the pits 27 indicating the address are formed on the substrate 26 (second substrate) side.

Since the substrate 26 is set to have a thickness which is approximately equal to the manufacturing tolerance of the substrate 8, the pit 27 indicating the address can be formed as a highly reliable embossed pit. In this case, if the embossed pits are formed in alignment along the area of the groove 5 of the substrate 8, the address and data are recorded in the same recording layer, so that the data layer 10 is relatively narrow as in the conventional case. It is possible to provide an address for each area. If the area of the groove 5 is eccentric (shifted) with respect to the row of embossed pits, 1
The data area indicated by one address extends over several rounds of the groove 5.

FIG. 5 shows a partial structure of a drive device for recording / reproducing information on / from the optical disc 25. An objective lens 6 is arranged at a position facing the optical disc 25, and an objective lens actuator 30 is arranged at a peripheral portion of the objective lens 6. A beam splitter 31 is arranged on the optical path of the objective lens 6, and the beam splitter 3
A semiconductor laser 32 and a light receiving element 33 are arranged on the optical paths separated by 1. A focus control circuit 34 is connected to the light receiving element 33. The focus control circuit 34 is connected to the objective lens actuator 30 via a calculator 35. The focus control circuit 34, the calculator 35, and the objective lens actuator 30 constitute a focus control means 36. Further, the light receiving element 33 includes an address detection circuit 37.
(Address detecting means) is connected. The address detection circuit 37 is connected to the focus jump circuit 39 via the controller 38. The controller 38 and the focus jump circuit 39 constitute a beam transfer means 40.

In such a structure, the semiconductor laser 3
The light beam emitted from the beam No. 2 is reflected by the beam splitter 31, condensed by the objective lens 6, and irradiated onto the surface of the optical disc 25. At this time, first, focus control is performed on the position of the pit 27 of the substrate 26 that will be the address layer. In this focus control, the reflected light from the optical disc 25 passes through the objective lens 6 and the beam splitter 31 and is detected by the light receiving element 33. The focus error signal Fe obtained by this is sent to the focus control circuit 34, and this focus control is performed. A control signal from the control circuit 34 is provided by driving and controlling the objective lens actuator 30 via the calculator 35. The focus error signal Fe can be detected by using a known detection method such as an astigmatism method.

With the focus control performed in this way, the reflected light from the pit 27 corresponding to the address layer is detected by the light receiving element 33, whereby the reproduction signal Rf is obtained.
Is generated. This reproduction signal Rf is supplied to the address detection circuit 3
7 and the address is detected. After this address detection, the control signal from the controller 38 is sent to the focus jump circuit 39. The focus jump circuit 39 gives an instantaneous offset to the actuator drive voltage of the objective lens actuator 30 output from the focus control circuit 34. As a result, focus control is performed and the light beam can be moved from the position of the address layer of the substrate 26 to the position of the data layer 10, and data can be recorded / reproduced at random positions. Further, when shifting the focus control from the data layer 10 to the address layer, the focus jump circuit 39 can give a momentary offset contrary to the case described above by a control signal from the controller 38. .
As a means for giving an instantaneous offset to the actuator drive voltage, it is possible to use a method of jumping to an adjacent track position which is performed by tracking control.

As described above, by providing the transparent second substrate 26 between the data layer 10 and the pits 27 indicating the address layer, it is possible to reliably detect each information as a change in the amount of reflected light. it can. Further, since the address is formed as the embossed pit on the transparent substrate 26, the desired address can be formed by simple molding.

Further, after the light beam is focused on the pit 27 on the substrate 26 showing the address layer and the address is detected from the reflected light, the light beam is pit 2 based on the control signal.
By moving the data from the position 7 to the data layer 10 and detecting the data, time division processing of address detection and data reproduction can be performed.

Next, a modified example of the second embodiment will be described with reference to FIG. 6 (corresponding to the invention of claim 11). The same parts as those in the second embodiment are designated by the same reference numerals.

FIG. 6A shows the configuration of the signal detection optical system in the drive device. The optical disc 25 is shown in a simplified manner in the data layer 10 and the address layer 27a (positions corresponding to the pits 27 on the substrate 26 in FIG. 4). In this case, the pit 25 (emboss pit) of the address layer 27a
Are formed so as to be aligned substantially along the groove 5 of the substrate 8.

An objective lens 6 is arranged at a position facing the optical disc 25, and a focus control means (not shown) for controlling the focus of the light beam condensed by the objective lens 6 to a predetermined position in the optical disc 25. No) is provided. A light receiving element 41 is arranged on the optical path of the objective lens 6. As shown in FIG. 6B, the light receiving element 41 is composed of a circular light receiving surface 41a formed in the central portion and a donut-shaped light receiving surface 41b formed in the peripheral portion thereof. The light receiving surface 41a is connected to the data reproducing circuit 42 (data reproducing means), and the light receiving surface 41b is connected to the address reproducing circuit 43 (address reproducing means).

In such a structure, light from a semiconductor laser (not shown) is applied to the data layer 10 of the optical disk 25 by the objective lens 6 in a state where the focal point P ₁ is formed. As a result, the reflected light from the data layer 10 passes through the objective lens 6 and the light receiving surface 41 of the light receiving element 41.
Irradiation is performed with the focal point P ₂ being focused on a.

Further, when the light beam is irradiated onto the data layer 10 in such a state that the focal point P ₁ is formed, the data layer 10 is a transparent film, so that the data layer 10 is formed.
The light beam that has passed through is irradiated onto the address layer 27a in a defocused state. In this case, the address layer 27
Since the light beam guided to a has an imaginary focal point Q ₁ , the reflected light from the address layer 27a has a tentative focal point Q ₂
Then, the light beam is irradiated onto the region of the donut-shaped light receiving surface 41b of the light receiving element 41 in a spread state.

In this case, the light receiving output from the light receiving surface 41a contains many signals from the data layer 10, and
The received light output of b includes many signals from the address layer 27a. Thus, the data signal Rf can be generated by sending the received light output from the light receiving surface 41a to the data reproducing circuit 42, and the received light output from the light receiving surface 41b can be sent to the address reproducing circuit 43 for processing. The address signal Ad can be generated by. Therefore, the data information can be detected from the focused light beam, and at the same time, the address information can be reproduced from the defocused light beam.

When the address and the data are recorded on the same recording layer 3 as in the conventional example (see FIG. 7), the width of the groove 5 must be equal to or larger than the width of the recording pit 5a indicating the data. While the meandering of the groove 5 must be suppressed to the extent that the recording pit does not protrude, in the case where the address is recorded in the independent address layers 12 and 27a as in each of the above embodiments. In addition, the width of the groove for the address may be formed thin, and the meandering degree of the groove for the address can be increased, so that a sufficient signal amplitude can be obtained. As a result, the capacity of the address and the signal amplitude are not restricted, and the data capacity is not restricted accordingly, and the storage capacity can be greatly improved.

[0052]

According to the invention described in claim 1, since the recording layer for address information and the recording layer for data information are provided independently, address information having sufficient signal amplitude even if the track pitch becomes narrow. Therefore, it is possible to provide an optical information recording medium which can be surely reproduced and whose storage capacity is significantly improved.

According to the second aspect of the present invention, the address information is recorded as a magneto-optical signal on the address information recording layer made of a magneto-optical material. Therefore, the address information and the light amount change signal by the magneto-optical signal are recorded. The data information other than the address can be reproduced at the same time, and the signal processing can be speeded up.

According to the third aspect of the invention, since the recording layer for data information is composed of a rewritable recording material, recording on the recording layer for data information occurs at the time of recording on the recording layer for address information. However, since the rewriting can be freely performed thereafter, no problem occurs in the recording layer for the data information, and thus the error rate can be reduced and the yield can be improved.

According to the fourth aspect of the present invention, since address information by magneto-optical recording is recorded in advance on the recording layer for address information, it is possible to save the trouble of address recording after shipping.
As a result, work efficiency can be improved and
The magneto-optical recording function on the drive device side becomes unnecessary.

According to the fifth aspect of the present invention, the recording layer for data information is formed on the side of the substrate on which the light beam is incident, and the recording layer for address information is formed at a position distant from the substrate. It is possible to reliably perform recording on the recording layer and to effectively use the recording power.

According to the sixth aspect of the present invention, the light transmissive heat dissipation layer is interposed between the recording layer for address information and the recording layer for data information. Therefore, the recording layer for address information is formed at the time of data recording. It can be prevented from being heated and the magnetization direction of the magneto-optical film can be stabilized, whereby highly reliable recording / reproducing of information can be performed.

According to a seventh aspect of the present invention, a light beam is focused on a region of a recording layer of an optical information recording medium, an address signal is reproduced from a difference signal of reflected light from the medium, and a sum signal of the reflected light is reproduced. Since the data signal is reproduced from, it is possible to process address detection and data reproduction at the same time.
This makes it possible to provide a device capable of high-speed data processing.

According to the eighth aspect of the present invention, since the transparent second substrate is provided between the recording layer for address information and the recording layer for data information, each information is surely changed as a light quantity change of reflected light. It is possible to detect and eliminate the trade-off between the data capacity and the address capacity (or the address signal amplitude), which makes it possible to obtain appropriate address information on a transparent substrate even when the track pitch is narrow. It becomes possible to form it as a pre-pit.

According to the ninth aspect of the present invention, since the address is formed as a prepit in the recording layer on the transparent substrate, a desired address can be formed by a simple molding, the manufacturing process can be simplified, and the reliability can be improved. It is possible to obtain highly accurate address information.

According to a tenth aspect of the present invention, after the light beam is focused on the recording layer for address information and an address signal is detected from the reflected light, the light beam is changed to a recording layer for address information based on the detection signal. Since the data signal is detected by shifting the recording layer to the data information recording layer, it is possible to provide an apparatus capable of performing address detection and data reproduction in time division.

In the eleventh aspect of the present invention, the defocusing light beam is emitted while the reflected light from the recording layer for data information irradiated with the focusing light beam is detected to reproduce the data signal. Since the address signal is reproduced by detecting the reflected light from the irradiated recording layer for address information, it is possible to perform the address detection and the data reproduction at the same time, which makes the structure relatively simple. It is possible to provide a device capable of high-speed data processing.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical disc according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a drive device used for the optical disc of FIG.

FIG. 3 is a waveform diagram showing various signal waveforms detected by the drive device.

FIG. 4 is a perspective view showing a second embodiment of the present invention with a part of the optical disc cut away.

5 is a block diagram showing a configuration of a drive device used for the optical disc of FIG.

FIG. 6 shows a modified example of the second embodiment of the present invention, in which (a) is a block diagram showing a configuration of a drive device,
(B) is a front view of the light receiving element.

FIG. 7 shows an example of the configuration of a conventional optical disc,
It is a perspective view which cuts and shows a part of optical disk.

[Explanation of symbols]

 7 Optical Information Recording Medium 10 Second Recording Layer 11 Heat Dissipation Layer 12 First Recording Layer 20 Address Reproducing Means 21 Data Reproducing Means 25 Optical Information Recording Medium 26 Substrate 27 Pre-Pits 36 Focus Control Means 37 Address Detecting Means 40 Beam Transition Means 42 Data reproducing means 43 Address reproducing means

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[Procedure amendment]

[Submission date] September 22, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

Conventionally, CD-R (Compact Dis c Reco
Rdable) or, MD (Mini Dis c) "Development of a mini disc system" poly file, 93,5, in the type of optical disc media such P.34～36 (optical information recording medium), an absolute address on the disk ( Alternatively, in order to display the absolute time), the address (or time) information is FM-modulated, and the track groove is slightly meandered according to the modulation.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

In such a structure, the light beam emitted from the laser light source (not shown) is condensed by the objective lens 6 and enters from the substrate 8 side of the optical disk 7. As a result, the light beam reaches the data layer 10 and the phase of the recording film is changed, whereby a recording mark corresponding to the data information is formed, and thereby information is recorded on the optical disc 7. When reproducing information from the optical disk 7,
Similarly, when the light beam is incident from the substrate 8 side and is irradiated on the data layer 10, the recording mark changes the light intensity distribution of the reflected light, and the magneto-optical mark on the address layer 12 further changes the reflected light. The plane of polarization is rotated.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

In this case, the data layer 10 gives strength to the reflected light but does not affect the polarization direction of the reflected light, so that the rotation direction of the reflected light itself does not change, whereby the polarity of the magneto-optical signal causes the data to disappear. An address signal independent of the signal can be accurately detected. Further, although the address layer 12 rotates in the polarization direction of the reflected light, but does not affect the reflected light amount, the data signal can be accurately reproduced by detecting the intensity of the reflected light amount. FIG.
The waveform 22 of the detected data signal, the waveform 23 of the address signal when there is no recording mark, and the waveform 24 of the address signal modulated by the strength of the data signal are shown in comparison. In this case, as can be seen from the waveform 24, although it is modulated to some extent in proportion to the strength of the waveform 22, it is understood that the polarity has not changed, and the address signal can be accurately detected. In this way, the address information and the data information can be reproduced simultaneously from the optical disc 7.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

Further, in this embodiment, the addressing layer 12 on the assumption that the address magneto-optical marks are recorded in at to have a magnetic head drive device, having a magneto-optical recording function In this case, the user can write the address by himself / herself at the first stage of use.
In this case, the recording power of the light beam incident from the substrate 8 side requires a considerably large value, but the efficiency is improved by setting the incident direction of the light beam on the opposite side to the substrate 8 as shown in the direction A of FIG. How to write address information well
Can also be considered . Further, when the data layer 10 is made of a rewritable material (phase change, magneto-optical), by recording from the direction A, only the address can be recorded at the stage before shipment. Thus, the user can save the trouble of address recording. When writing to the address layer 12, an address may be recorded on the data layer 10 due to heating by a light beam. However, by making the data layer 10 a rewritable material, it is possible to easily rewrite thereafter. There is no problem because it is done.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction content]

FIG. 4 shows the sectional shape of the optical disk 25. A phase change data layer 10 is formed on a substrate (made of polycarbonate) 8 via a protective layer 9. A transparent substrate 26 is provided on the data layer 10. The substrate 26 is a so-called second substrate having a thickness (about 50 μm) which is about the manufacturing tolerance of the substrate 8 (first substrate). The material of the substrate 26 is made of photopolymer, and the substrate surface is an area for recording address information (area corresponding to the address layer 12). Pits 27 are formed on the surface of the substrate 26 as pre-pits indicating address information. The pits 27 are formed by a stamper after the photopolymer is applied to the substrate 26, and are cured by the irradiation of ultraviolet rays.
Are located directly above the grooves 5 and are arranged along the groove forming direction. And such a pit 27
A reflective layer 28 and a protective layer 29 made of an ultraviolet curable resin are sequentially laminated on the substrate 26 on which is formed. Thus, in the optical disc 25, the data layer 10 is formed on the substrate 8 (first substrate) side, and the pits 27 indicating the address are formed on the substrate 26 (second substrate) side.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction content]

With the focus control performed in this way, the reflected light from the pit 27 corresponding to the address layer is detected by the light receiving element 33, whereby the reproduction signal Rf is obtained.
Is generated. This reproduction signal Rf is supplied to the address detection circuit 3
7 and the address is detected. After this address detection, the control signal from the controller 38 is sent to the focus jump circuit 39. The focus jump circuit 39 gives an instantaneous offset to the actuator drive voltage of the objective lens actuator 30 output from the focus control circuit 34. As a result, focus control is performed and the light beam can be moved from the position of the address layer of the substrate 26 to the position of the data layer 10, and data can be recorded / reproduced at random positions. Further, when shifting the focus control from the data layer 10 to the address layer, the focus jump circuit 39 can give a momentary offset contrary to the case described above by a control signal from the controller 38. .
As the means for providing a momentary offset to the actuator driving voltage can be performed by using the procedure to jump to an adjacent track position being performed by the tracking control.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

In this case, the light receiving output from the light receiving surface 41a contains many signals from the data layer 10, and
The received light output of b contains many signals from the address layer 27a. Thus, the data signal Rf can be generated by sending the received light output from the light receiving surface 41a to the data reproducing circuit 42, and the received light output from the light receiving surface 41b can be sent to the address reproducing circuit 43 for processing. The address signal Ad can be generated by. Therefore, the data information can be detected from the focused light beam, and at the same time, the address information can be reproduced from the defocused light beam.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0051

[Correction method] Change

[Correction content]

When the address and the data are recorded on the same recording layer 3 as in the conventional example (see FIG. 7), the width of the groove 5 must be equal to or larger than the width of the recording pit 5a indicating the data. While it is necessary to suppress the meandering of the groove 5 to the extent that the recording pit does not protrude, the meandering of the groove is used instead of the prepit.
Data layer 10 and address layer 27 when displaying a reply
With two layers a, the groove itself may be formed to have a small width, and the meandering degree of the groove for the address can be increased, so that a sufficient signal amplitude can be obtained. As a result, the capacity of the address and the signal amplitude are not restricted, and the data capacity is not restricted accordingly, and the storage capacity can be greatly improved.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0062

[Correction method] Change

[Correction content]

The invention described in claim 11 is focusing.
While reproducing the data signal by detecting the reflected light from the recording layer for the data information which is irradiated with the generated light beam,
Since defocusing light beam was made to reproduce the detected and address signals reflected light from the recording layer of address information which has been irradiated, it is possible to simultaneously process an address detection and data reproduction, which Thus, it is possible to provide an apparatus capable of high-speed data processing with a relatively simple structure.

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

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Claims (11)

[Claims] 1. An optical information recording medium having a first recording layer for recording or reproducing at least address information, and a second recording layer for recording or reproducing at least data information other than the address information. . 2. The optical information recording medium according to claim 1, wherein the first recording layer is formed of a magneto-optical recording material. 3. The optical information recording medium according to claim 2, wherein the second recording layer is formed of a rewritable recording material. 4. The optical information recording medium according to claim 2, wherein address information by magneto-optical recording is recorded in advance on the first recording layer. 5. The second recording layer is formed on the side of the substrate on which the light beam is incident, and the first recording layer is formed at a position distant from the substrate. Optical information recording medium. 6. Between the first recording layer and the second recording layer,
3. A light-transmitting heat dissipation layer is provided.
The optical information recording medium as described in 3 or 4. 7. Focus control means for focusing a light beam on a region of a recording layer of the optical information recording medium according to claim 1, and reflected light from the optical information recording medium. 2. An optical information recording / reproducing apparatus comprising: an address reproducing means for reproducing an address signal from the difference signal of 1. and a data reproducing means for reproducing a data signal from a sum signal of reflected light from the optical information recording medium. 8. Between the first recording layer and the second recording layer,
The optical information recording medium according to claim 1, further comprising a transparent substrate. 9. The optical information recording medium according to claim 8, wherein a first recording layer having an address formed by prepits is provided on a transparent substrate. 10. A focus control means for focusing a light beam on each recording layer of the optical information recording medium according to claim 8, and a focus control means for focusing the light beam on a first recording layer. Address detecting means for detecting an address signal from reflected light, and beam shifting means for shifting the light beam focused on the first recording layer to the second recording layer based on the signal from the address detecting means. An optical information recording / reproducing apparatus comprising: 11. A focus control means for focusing a light beam on each recording layer of the optical information recording medium according to claim 8; and a focus control means for focusing the light beam on a second recording layer. Data reproducing means for detecting reflected light to reproduce a data signal, and detecting reflected light from the first recording layer while converging the light beam on the second recording layer to detect an address signal. An optical information recording / reproducing apparatus comprising: an address reproducing unit for reproducing the information.