JP2007317317A - Two-layer optical disk for testing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a two-layer optical disk for test suitable for adjusting optical pickup of an optical disk device, by virtually composing a recordable optical disk with a read-only optical disk. <P>SOLUTION: The two-layer optical disk for test is used for adjusting the optical pickup of the optical disk device. The two-layer optical disk includes: a first recording layer in which at least either of pit height or track pitch is adjusted in the read-only optical disk so as to obtain the same signals as those obtained by the optical pickup when the optically-recordable optical disk is reproduced; and a second recording layer in which at least either of the pit height or the track pitch is adjusted in the read-only optical disk so as to obtain the same signals as those obtained by the optical pickup when an optical disk of a type different from the recordable optical disk is reproduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a test double-layer optical disk used for optical pickup adjustment of an optical disk apparatus that reproduces a CD, DVD, HD DVD, Blu-ray disk, and the like.

  In an optical disc apparatus using an optical disc such as a CD, DVD, HD DVD, or Blu-ray disc as a recording medium, light is emitted from a light source built in the pickup in order to read information recorded on the optical disc during reproduction.

  Then, the light reflected by the optical disk is received by a photodetector in the pickup, and an error signal such as tracking is generated. Further, by driving the tracking servo based on this error signal, the pickup can follow the track of the optical disc.

  Here, a test optical disc is used to adjust the optical pickup of the optical disc apparatus. In this case, taking DVD as an example, various types of optical disks such as DVD-R, DVD + R, DVD-RW, DVD + RW, and DVD-RAM exist as recording DVDs.

  Then, when testing a plurality of types of optical discs in this way, a method of exchanging the discs for each inspection process and a plurality of types of optical discs bonded to each other at the inner and outer peripheral portions as shown in FIG. There is a method using a disk.

A technique for configuring a plurality of types of optical disks as one is described in Patent Document 1 below. Further, a technique for constructing a test optical disc is described in Patent Document 2 below.
Japanese Patent Laid-Open No. 11-25578 (first page, FIG. 1) Japanese Patent Laying-Open No. 2003-157588 (first page, FIG. 1)

  As shown in FIG. 3 above, when a plurality of types of optical discs are formed by laminating an inner peripheral disc and an outer peripheral ring-shaped disc, mechanical properties such as rotational balance, eccentricity accuracy, and durability are provided. There is a problem of low stability.

  In Patent Document 1, different formats are recorded in areas obtained by dividing an optical disk into a plurality of parts in the radial direction. Specifically, a standard CD format and a double-density CD format are recorded on a single playback-only CD.

  In Patent Document 2, a read-only optical disk that is set to be equivalent to the reflectance of a recordable optical disk is configured, and a recordable optical disk whose performance may change depending on the lot is stable. It describes that it is constructed in a pseudo manner by an optical disk dedicated to reproduction in a state.

  Note that even if the recordable optical disk is artificially constituted by a read-only optical disk, sufficient performance cannot be obtained as a test optical disk for adjusting the optical pickup of the optical disk device, focusing on the reflectance. .

  That is, since a recordable optical disc is recorded by a layer change or a dye change, a tracking error signal of an optical pickup appears differently from a read-only optical disc that is recorded depending on the presence or absence of pits. For this reason, when paying attention to the reflectance, the pseudo configuration is not sufficient. For this reason, it has been impossible to adjust the tracking error signal obtained at the time of reproduction by the optical pickup.

  In the three-beam tracking method of the optical pickup, a tracking error signal is generated using a preceding beam and a rear beam called a sub beam in addition to a main beam. When this optical pickup is adjusted, the RF signals of the preceding beam and the rear beam are adjusted so that each beam is irradiated so that a certain amount of phase difference is obtained with respect to the RF signal of the main beam. There is a need. When the phase difference is adjusted beyond this certain amount, the tracking capability of the optical pickup is greatly affected. The phase adjustment depends on the track pitch of the optical disk. Therefore, it is necessary to adjust the phase difference to a certain amount for each track pitch so that discs having different track pitches can be normally reproduced. Taking DVD as an example, DVD + R has a track pitch of 0.74 μm and DVD-RAM has a track pitch of 0.615 μm. Actually, when adjusting the pickup, the phase difference is adjusted to a certain amount for each track pitch. It is necessary to In addition, it is necessary to perform the main beam and sub beam phase adjustment of the optical pickup using the three-beam tracking method using a plurality of disks having different track pitches, and there is a problem that adjustment work is complicated. Was.

  The present invention artificially configures a recordable optical disc by a read-only optical disc, and pseudo-configures a plurality of types of recordable optical discs on one disc, and is suitable for adjustment of an optical pickup of an optical disc apparatus. An object of the present invention is to realize a test optical disc.

The present invention as means for solving the above-described problems is as described in the following (1) to (6).
(1) The invention described in claim 1 is a test double-layer optical disc used for optical pickup adjustment of an optical disc apparatus, and a signal obtained by the optical pickup when an optically recordable optical disc is reproduced. A first recording layer in which at least one of pit height or track pitch is adjusted in a read-only optical disc so that the same signal can be obtained, and the optical pickup obtains an optical disc of a different type from the optical disc. And a second recording layer in which at least one of the pit height or the track pitch is adjusted in a reproduction-only optical disc so that the same signal as that obtained can be obtained.

  (2) According to the second aspect of the present invention, the first recording layer and the second recording layer are arranged so that the same signal as that obtained by the optical pickup can be obtained when an optically recordable optical disk is reproduced. 2. The test double-layer optical disc according to claim 1, wherein both the pit height and the track pitch are adjusted.

  (3) The invention according to claim 3 is characterized in that the first recording layer has the same tendency as the characteristic of the tracking error signal obtained by the optical pickup when an optically recordable optical disk is reproduced. 2. The test double-layer optical disc according to claim 1, wherein both the pit height and the track pitch are adjusted in the second recording layer and the second recording layer.

  (4) In the invention according to claim 4, the order of the RF signal of the main beam and the RF signal of the sub beam obtained when a plurality of optically recordable optical disks having different track pitches is reproduced by a three-beam optical pickup. 2. The test double layer according to claim 1, wherein a track pitch is adjusted in the first recording layer and the second recording layer so as to obtain a characteristic having the same tendency as the phase difference characteristic. It is an optical disk.

  (5) The invention according to claim 5 is characterized in that when at least one of the first recording layer and the second recording layer reproduces a plurality of optically recordable optical discs of different types, 4. The reproduction-only optical disc has a plurality of areas in which at least one of the pit height or the track pitch is adjusted so that the same signal as that obtained by the pickup can be obtained. Or a test double-layer optical disc.

  (6) The invention according to claim 6 is characterized in that when at least one of the first recording layer and the second recording layer reproduces a plurality of optically recordable optical discs of different types, 5. The test double-layer optical disk according to claim 4, wherein the reproduction-only optical disk has a plurality of areas whose pit heights are adjusted so that the same signal as that obtained by the pickup is obtained.

According to the present invention, the following effects (1) to (6) can be obtained.
(1) According to the first aspect of the present invention, the test double-layer optical disk used for adjusting the optical pickup of the optical disk apparatus is constituted by a read-only double-layer optical disk, and the optical pickup is used when a recordable optical disk is reproduced. When playing back an optical disc of a type different from the first recording layer in which at least one of the pit height or track pitch is adjusted in a read-only optical disc so that a signal having the same characteristics as the obtained signal can be obtained And a second recording layer in which at least one of the pit height or the track pitch is adjusted in a read-only optical disc so that a signal having the same characteristics as the signal obtained by the optical pickup is obtained. deep.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, the test double-layer optical disk for adjusting the optical pickup of the optical disk device has sufficient performance when focusing on the reflectance. The disadvantage of not being obtained is eliminated by adjusting at least one of the pit height or the track pitch, and a signal having the same characteristics as that obtained by an optical pickup can be obtained when an optically recordable optical disk is reproduced. .

  This makes it possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by artificially configuring a recordable optical disc by a read-only optical disc.

  In addition, different recordable optical discs can be simulated by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that the physically stable state is maintained. Is possible.

  (2) In the invention according to claim 2, the first recording layer and the second recording layer are arranged so that a signal having the same characteristics as the signal obtained by the optical pickup can be obtained when an optically recordable optical disk is reproduced. In, both the pit height and the track pitch are adjusted.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, the test double-layer optical disk for adjusting the optical pickup of the optical disk device has sufficient performance when focusing on the reflectance. The disadvantage that it cannot be obtained is eliminated by adjusting both the pit height and the track pitch, and a signal having the same characteristics as the signal obtained by the optical pickup when an optically recordable optical disk is reproduced can be obtained.

  This makes it possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by artificially configuring a recordable optical disc by a read-only optical disc.

  In addition, different recordable optical discs can be simulated by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that the physically stable state is maintained. Is possible.

  (3) In the invention according to claim 3, the first recording layer and the second recording layer are provided so that characteristics having the same tendency as the characteristics of the tracking error signal obtained by the optical pickup can be obtained when a recordable optical disk is reproduced. Then, both the pit height and the track pitch are adjusted.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, it is sufficient to pay attention to the reflectance as a test double-layer optical disk for adjusting the tracking of the optical pickup of the optical disk device. The disadvantage that performance cannot be obtained is eliminated by adjusting both the pit height and the track pitch, and when the optically recordable optical disk is reproduced, a signal having the same characteristics as the signal obtained by the optical pickup can be obtained. .

  This makes it possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by artificially configuring a recordable optical disc by a read-only optical disc.

  In addition, different recordable optical discs can be simulated by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that the physically stable state is maintained. Is possible.

  (4) In the invention according to claim 4, the order of the RF signal of the main beam and the RF signal of the sub beam obtained when a plurality of optically recordable optical disks having different track pitches is reproduced by a three-beam optical pickup. The track pitch is adjusted in the first recording layer and the second recording layer so that characteristics having the same tendency as the phase difference characteristics can be obtained.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, the reflectivity is considered as a test double-layer disk for adjusting the phase of the three-beam optical pickup of the optical disk device. The disadvantage that sufficient performance cannot be obtained is eliminated by adjusting the track pitch.

  This makes it possible to realize a test double-layer optical disc in a state suitable for phase adjustment of the three-beam optical pickup of the optical disc apparatus by simulating a recordable optical disc by a read-only optical disc.

  In other words, in an optical disc composed of two layers, a media signal having a different track pitch is recorded in each of the first layer and the second layer. The phase of the optical pickup can be adjusted efficiently for two types of media with different track pitches on the disc.

  (5) The invention according to claim 5 is obtained by an optical pickup when reproducing a plurality of optically recordable optical discs of different types in at least one of the first recording layer and the second recording layer. A plurality of areas in which at least one of the pit height or the track pitch is adjusted are provided on the reproduction-only optical disc so that the same signal as that obtained can be obtained.

  As a result, it is possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by simulating three or four or more types of recordable optical discs by a read-only optical disc. Become.

  Also, different recordable optical discs can be reproduced by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that three or more types of recording can be performed. Although the optical disk is constructed in a pseudo manner, it becomes possible to maintain a physically stable state.

  (6) The invention according to claim 6 is obtained by an optical pickup when reproducing a plurality of optically recordable optical discs of different types in at least one of the first recording layer and the second recording layer. A plurality of areas in which the track pitch is adjusted are provided on a reproduction-only optical disc so that the same signal as that obtained can be obtained.

  As a result, it is possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by simulating three or four or more types of recordable optical discs by a read-only optical disc. Become.

  Also, different recordable optical discs can be reproduced by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that three or more types of recording can be performed. Although the optical disk is constructed in a pseudo manner, it becomes possible to maintain a physically stable state.

The best mode (embodiment) for carrying out the present invention will be described below in detail with reference to the drawings.
The read-only test double-layer optical disc of the first embodiment will be described with reference to FIG.

  First, in FIGS. 1A and 1B, a first substrate 11 that is a transparent substrate that is made of polycarbonate or the like and is closest to the light incident surface, and a layer L0 that is closest to the light incident surface. 1 is a first reflective film 21 formed on the first substrate 11 constituting In this case, the lower side of the paper in FIGS. 1A and 1B is the light incident surface.

  In FIG. 1C and FIG. 1D, the second substrate 12 that is made of polycarbonate or the like and is a transparent substrate far from the light incident surface, and the layer L1 that is far from the light incident surface. This is a second reflective film 22 formed on the second substrate 12. In this case, the upper side in FIG. 1C and FIG.

  1 (e) and FIG. 1 (f) which is an enlarged view thereof, the first substrate 11 which is a transparent substrate which is made of polycarbonate or the like and is closest to the light incident surface, and the light incident surface. A first reflective film 21 formed on the first substrate 11 constituting the closest layer L0, a second substrate 12 made of polycarbonate or the like, which is a transparent substrate far from the light incident surface, and a light incident surface It is the 2nd reflective film 22 comprised in the 2nd board | substrate 12 which comprises the layer L1 of the side far from. In this case, two layers for test are formed by bonding using the adhesive layer 30 constituting the intermediate layer and the first substrate 11 of FIG. 1B and the second substrate 12 of FIG. 1D reversed. An optical disc is configured. In this case, the lower side of the paper in FIGS. 1E and 1F is the light incident surface. Furthermore, a label surface 40 on which a label or the like is printed is configured on the side opposite to the light incident surface.

  Here, as shown in FIG. 1 (f), which is a partially enlarged view of FIG. 1 (e), the first substrate 11 and the second substrate 12 are each formed with pits as read-only optical disks. The light from the objective lens of the optical pickup is irradiated.

  Further, here, the first substrate 11 and the first reflective film 21 constitute the first recording layer in the claims. Here, the second substrate 12 and the second reflective film 22 constitute a second recording layer in the claims.

A method for manufacturing the reproduction test double-layer optical disc having the above-described configuration will be described in order.
[Step 1-1]
First, a DVD-ROM single-layer stamper is used as a stamper on which digital data information is formed, and a first substrate having a thickness of 0.6 mm and having information source pits all around by injection molding or 2P method. 11 is made.

  Here, the pit height and track pitch of the first substrate 11 are optically recordable optical discs (DVD-R, DVD + R, DVD-RW) with the lower planes of FIGS. , DVD + RW or DVD-RAM) is determined so that the same signal as that obtained by the optical pickup can be obtained.

  That is, the pit height and the track pitch of the first recording layer are determined so that characteristics having the same tendency as the characteristics of the tracking error signal obtained by the optical pickup can be obtained when an optically recordable optical disk is reproduced.

  Or, the characteristics having the same tendency as the characteristics of the phase difference between the RF signal of the main beam and the RF signal of the sub beam obtained when a plurality of optically recordable optical disks having different track pitches are reproduced by a three-beam optical pickup. The track pitch of the first recording layer is determined so as to be obtained.

[Step 1-2]
Next, a first reflection film 21 for total reflection is formed by vacuum deposition or the like using a sputtering apparatus or the like from the inner circumference to the middle circumference on the first substrate 11.

[Step 2-1]
Then, a stamper which is a DVD dual layer parallel track path is used as a stamper on which information of digital data is formed, and an information source pit is provided around the entire circumference by an injection molding method or a 2P method. Two substrates 12 are made.

  Here, the pit height and the track pitch of the second substrate 12 are different from those of the first substrate 11, and the pit height and the track pitch are different from those of the first substrate 11. In addition, the upper uneven surface in FIGS. 1C and 1D is used as a light incident surface, and the spiral direction is also reversed. Then, when an optically recordable optical disc (DVD-R, DVD + R, DVD-RW, DVD + RW, or DVD-RAM) is reproduced, the same signal as that obtained by the optical pickup is determined. To do.

  That is, the pit height and track pitch of the second recording layer are determined so that characteristics having the same tendency as the characteristics of the tracking error signal obtained by the optical pickup can be obtained when an optically recordable optical disk is reproduced.

  Or, the characteristics having the same tendency as the characteristics of the phase difference between the RF signal of the main beam and the RF signal of the sub beam obtained when a plurality of optically recordable optical disks having different track pitches are reproduced by a three-beam optical pickup. The track pitch of the second recording layer is determined so as to be obtained.

[Step 2-2]
Next, a second reflection film 22 for total reflection is formed by vacuum deposition or the like using a sputtering apparatus or the like from the middle circumference to the outer circumference on the second substrate 12.

[Step 3]
The first substrate 11 created in step [1-1] and step [1-2] and the second substrate 12 created in step [2-1] and step [2-2] are mutually connected. The reflective film 21 and the reflective film 22 are bonded to each other with the adhesive layer 30 therebetween. In this case, the thickness of the adhesive layer 30 is adjusted so that the entire thickness of the double-layer optical disc is set.

[Step 4]
Further, a label or the like is printed on the flat surface of the second substrate 12 to complete a test double-layer optical disc.

Hereafter, the characteristic part of this invention is demonstrated in detail.
Recordable optical discs such as DVD-R, DVD + R, DVD-RW, DVD + RW, and DVD-RAM are recorded by layer change or dye change. Therefore, a read-only optical disc (DVD- The appearance of a tracking error signal of an optical pickup is different from that of a ROM.

  For this reason, the pseudo configuration is not sufficient when focusing on the reflectance as in the prior art. Therefore, in this embodiment, attention is paid to the pit height Hp and the track pitch Pt. The pit height is sometimes referred to as pit depth, but in this specification, it is referred to as pit height.

  That is, in the read-only optical disk of the present embodiment, as a test double-layer optical disk for adjusting the tracking of the optical pickup of the optical disk device, a sufficient performance cannot be obtained by focusing on the reflectance. The configuration is as follows.

  (1) A test double-layer optical disk used for optical pickup adjustment of an optical disk device is constituted by a read-only double-layer optical disk, and a signal having the same characteristics as a signal obtained by an optical pickup when a recordable optical disk is reproduced The first recording layer in which at least one of the pit height or the track pitch is adjusted in a read-only optical disc, and the signal obtained by the optical pickup when reproducing an optical disc of a different type from the optical disc In order to obtain a signal having the same characteristics as those described above, a read-only optical disc is provided with a second recording layer in which at least one of the pit height or the track pitch is adjusted.

  In this case, a signal obtained by an optical pickup when reproducing various recordable optical discs such as an optical disc recorded by dye change and an optical disc recorded by layer change is obtained in advance, and the same signal as that signal is obtained. Therefore, it is desirable to adjust the pit height Hp and the track pitch Pt in a reproduction-only optical disc so that can be obtained by pickup.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, the test double-layer optical disk for adjusting the optical pickup of the optical disk device has sufficient performance when focusing on the reflectance. The disadvantage of not being obtained is eliminated by adjusting at least one of the pit height or the track pitch, and a signal having the same characteristics as that obtained by an optical pickup can be obtained when an optically recordable optical disk is reproduced. .

  This makes it possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by artificially configuring a recordable optical disc by a read-only optical disc.

  In addition, different recordable optical discs can be simulated by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that the physically stable state is maintained. Is possible.

  (2) Preferably, pits are formed in the first recording layer and the second recording layer so that a signal having the same characteristics as the signal obtained by the optical pickup can be obtained when an optically recordable optical disk is reproduced. Adjust both height and track pitch.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, the test double-layer optical disk for adjusting the optical pickup of the optical disk device has sufficient performance when focusing on the reflectance. The disadvantage that it cannot be obtained is eliminated by adjusting both the pit height and the track pitch, and a signal having the same characteristics as the signal obtained by the optical pickup when an optically recordable optical disk is reproduced can be obtained.

  This makes it possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by artificially configuring a recordable optical disc by a read-only optical disc.

  In addition, different recordable optical discs can be simulated by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that the physically stable state is maintained. Is possible.

  (3) More preferably, the pits are formed in the first recording layer and the second recording layer so that characteristics having the same tendency as the characteristics of the tracking error signal obtained by the optical pickup when a recordable optical disc is reproduced can be obtained. Adjust both height and track pitch.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, it is sufficient to pay attention to the reflectance as a test double-layer optical disk for adjusting the tracking of the optical pickup of the optical disk device. The disadvantage that performance cannot be obtained is eliminated by adjusting both the pit height and the track pitch, and when the optically recordable optical disk is reproduced, a signal having the same characteristics as the signal obtained by the optical pickup can be obtained. .

  This makes it possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by artificially configuring a recordable optical disc by a read-only optical disc.

  In addition, different recordable optical discs can be simulated by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that the physically stable state is maintained. Is possible.

  (4) The same tendency as the phase difference characteristic between the main beam RF signal and the sub beam RF signal obtained when a plurality of optically recordable optical disks having different track pitches are reproduced by a three-beam optical pickup. The track pitch is adjusted in the first recording layer and the second recording layer so that the above characteristics can be obtained.

  As a result, when a recordable optical disk is constructed by a reproduction-only optical disk, the reflectivity is considered as a test double-layer disk for adjusting the phase of the three-beam optical pickup of the optical disk device. The disadvantage that sufficient performance cannot be obtained is eliminated by adjusting the track pitch.

  This makes it possible to realize a test double-layer optical disc in a state suitable for phase adjustment of the three-beam optical pickup of the optical disc apparatus by simulating a recordable optical disc by a read-only optical disc.

  Also, different recordable optical discs can be simulated in different layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches. Is possible.

  (5) Further, in at least one of the first recording layer and the second recording layer, the same signal as that obtained by the optical pickup when a plurality of optically recordable optical discs of different types is reproduced. As can be obtained, a plurality of areas in which at least one of the pit height or the track pitch is adjusted are provided on a read-only optical disc.

  Here, the pit height and track pitch of the first substrate 11 are optically recordable optical discs (DVD-R, DVD + R, DVD-RW) with the lower planes of FIGS. , DVD + RW, DVD-RAM), so that the same signal as that obtained by the optical pickup can be obtained, and in the first area (inner circumference) and the second area (middle circumference) Decide to accommodate different optical disks. In addition, you may comprise so that it can respond to a several area | region similarly in the 2nd board | substrate 12 (refer FIG.2 (c) (d)). As in the case of FIG. 1, the first substrate 11 and the second substrate 12 are bonded to each other via the adhesive layer 30 so that the reflective film 21 and the reflective film 22 face each other. In this case, the thickness of the adhesive layer 30 is adjusted so that the entire thickness of the double-layer optical disc is set.

  As a result, it is possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by simulating three or four or more types of recordable optical discs by a read-only optical disc. Become.

  Also, different recordable optical discs can be reproduced by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that three or more types of recording can be performed. Although the optical disk is constructed in a pseudo manner, it becomes possible to maintain a physically stable state.

  (6) Further, in at least one of the first recording layer and the second recording layer, the same signal as that obtained by the optical pickup when a plurality of optically recordable optical discs of different types is reproduced. As obtained, a plurality of areas in which the track pitch is adjusted are provided on a reproduction-only optical disc.

  As a result, it is possible to realize a test double-layer optical disc in a state suitable for adjustment of the optical pickup of the optical disc apparatus by simulating three or four or more types of recordable optical discs by a read-only optical disc. Become.

  Also, different recordable optical discs can be reproduced by two layers, and each layer is composed of the same read-only optical discs with different pit heights and track pitches, so that three or more types of recording can be performed. Although the optical disk is constructed in a pseudo manner, it becomes possible to maintain a physically stable state.

  In order to adjust the optical pickup of the optical disk apparatus by using the configuration as described in (1) to (6) above, when the test double-layer optical disk is a DVD, a read-only DVD-ROM is used. Thus, it is possible to simulate two types or three or more types of various optical discs of recording DVDs (DVD-R, DVD + R, DVD-RW, DVD + RW, DVD-RAM).

  In addition, when the inventor conducted an experiment, when reproducing various recordable optical disks with a reproduction-only optical disk, good results were obtained by setting the pit height Hp and the track pitch Pt as follows. .

  In general, in a read-only DVD-ROM, the tracking error signal is maximum at a pit height λ / 8n, and the tracking error signal is minimum at a pit height λ / 4n. Further, in the detection of the tracking error signal by phase difference detection as in the 3-beam method, the tracking error signal changes when the track pitch changes. The track pitch of DVD-RAM is 0.615 μm, and the track pitch of DVD ± R and DVD ± RW is 0.74 μm.

  In this case, an optically recordable optical disc can be obtained by forming a read-only DVD-ROM using any two of the following (1) to (5) as the first recording layer and the second recording layer. When reproducing, the same signal as that obtained by the optical pickup can be obtained. Note that any combination of the first recording layer and the second recording layer may be used.

  (1) DVD-R: By setting the pit height Hp to 150 nm and the track pitch Pt to 0.74 μm, the same tracking error signal as the push-pull signal obtained when reproducing the DVD-R was obtained.

  (2) DVD + R: By setting the pit height Hp to 150 nm and the track pitch Pt to 0.74 μm, the same tracking error signal as the push-pull signal obtained when the DVD + R was reproduced was obtained.

  (3) DVD-RW: By setting the pit height Hp to 30 nm and the track pitch Pt to 0.74 μm, the same tracking error signal as the push-pull signal obtained when reproducing the DVD-RW was obtained.

  (4) DVD + RW: By setting the pit height Hp to 30 nm and the track pitch Pt to 0.74 μm, the same tracking error signal as the push-pull signal obtained when DVD + RW was reproduced was obtained.

  (5) DVD-RAM: By setting the pit height Hp to 70 nm and the track pitch Pt to 0.615 μm, the same tracking error signal as the push-pull signal obtained when reproducing the DVD-RAM was obtained.

Note that the above experimental results are based on the material used by the applicant of the present invention for the experiment, and detailed specific numerical values may vary when the composition of the materials is different.
Further, according to the present embodiment, by adjusting the pit height Hp and the track pitch Pt, the same characteristics as those of a signal obtained by an optical pickup of one beam when an optically recordable optical disk is reproduced. Adjust so that signals can be obtained, or when reproducing a plurality of optically recordable optical discs with different track pitches, a signal having the same characteristics as those obtained with a three-beam optical pickup is obtained. It is also possible.

  For example, the first recording layer composed of the first substrate 11 and the first reflective film 21 has a pit height Hp of 150 nm and a track pitch Pt of 0.74 μm, and the second substrate 12 and the second reflective film 22. The second recording layer is configured to have a pit height Hp of 70 nm and a track pitch Pt of 0.615 μm, so that the first recording layer is a DVD + R and the second recording layer is a DVD-RAM read-only optical disc. It becomes possible to configure in a pseudo manner. As a result, a signal having the same characteristics as the signal obtained by the optical pickup when two types of optically recordable optical disks are reproduced can be obtained.

  The combination of the first recording layer and the second recording layer is not limited to the above example. Further, the specific numerical values of the pit height Hp and the track pitch Pt are not limited to the above values. Further, the range in which the reflective film is provided (the first reflective film (inner circumference to middle circumference) and the second reflective film (middle circumference to outer circumference)) is not limited to the above specific examples.

  As a result of the configuration as described above, it is possible to reduce the problem that the performance varies depending on the lot of recordable optical discs when the optical pickup is tested. Further, not only can the recordable optical disk be configured by a reproduction-only optical disk in a pseudo manner, but also a sufficient performance can be obtained as a test double-layer optical disk for adjusting the optical pickup of the optical disk apparatus.

  In other words, according to this embodiment, a recordable optical disk is formed by a reproduction-only optical disk, and a test double-layer optical disk in a state suitable for adjustment of the optical pickup of the optical disk apparatus can be realized. . In this case, different recordable optical discs can be reproduced in a plurality of layers of the first recording layer and the second recording layer, and the plurality of regions have the same reproduction although at least one of pit height and track pitch is different. Since it is constituted by a dedicated optical disk, it becomes possible to maintain a physically stable state. In addition, since an optical disc that can be recorded with a read-only optical disc can be configured in a pseudo manner, manufacturing costs can be reduced.

  Also, in an apparatus capable of reproducing a plurality of standard recordable optical discs, the optical pickup can be adjusted for a plurality of standard optical discs without exchanging the discs. Adjustment is possible under uniform conditions, which is preferable. In addition, since it is not necessary to replace the disk, it is possible to suppress the consumption of the disk and the apparatus.

  Note that the test disc in the above embodiment is useful as a test disc for various optical discs of existing standards as long as it conforms to the specification of a DVD single-sided dual layer disc. Moreover, it is also possible to apply to various optical discs that are not included in the specification of the DVD single-sided dual layer disc.

It is sectional drawing which shows the cross-sectional structure of the test double layer optical disk which is embodiment of this invention. It is sectional drawing which shows the cross-sectional structure of the test double layer optical disk which is embodiment of this invention. It is sectional drawing which shows the cross-sectional structure of the conventional double-layer optical disk for a test.

Explanation of symbols

11 First substrate 12 Second substrate 21 First reflective film 22 Second reflective film 30 Intermediate layer 40 Label surface

Claims (6)

A test double-layer optical disk used for optical pickup adjustment of an optical disk device,
First recording layer in which at least one of pit height or track pitch is adjusted in a read-only optical disc so that the same signal as that obtained by the optical pickup can be obtained when reproducing an optically recordable optical disc When,
Second recording in which at least one of the pit height and the track pitch is adjusted on a read-only optical disc so that the same signal as that obtained by the optical pickup can be obtained when an optical disc of a different type from the optical disc is reproduced. Layers,
A double-layer optical disc for testing, comprising: Both the pit height and the track pitch in the first recording layer and the second recording layer so that the same signal as that obtained by the optical pickup can be obtained when an optically recordable optical disc is reproduced. Has been adjusted,
The test double-layer optical disc according to claim 1. The pit height is increased in the first recording layer and the second recording layer so that the same characteristic as the characteristic of the tracking error signal obtained by the optical pickup can be obtained when the optically recordable optical disk is reproduced. And track pitch are both adjusted,
The test double-layer optical disc according to claim 1. A characteristic having the same tendency as the characteristic of the phase difference between the RF signal of the main beam and the RF signal of the sub beam obtained when a plurality of optically recordable optical disks having different track pitches is reproduced by a three-beam optical pickup can be obtained. As described above, the track pitch is adjusted in the first recording layer and the second recording layer,
The test double-layer optical disc according to claim 1. In at least one of the first recording layer and the second recording layer, the same signal as that obtained by the optical pickup can be obtained when a plurality of optically recordable optical discs of different types are reproduced. As described above, it has a plurality of areas in which at least one of the pit height or the track pitch is adjusted in a read-only optical disc,
The test double-layer optical disc according to any one of claims 1 to 3. In at least one of the first recording layer and the second recording layer, the same signal as that obtained by the optical pickup can be obtained when a plurality of optically recordable optical discs of different types are reproduced. As described above, the read-only optical disc has a plurality of areas in which the pit height is adjusted,
The test double-layer optical disc according to claim 4.

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