JP3651187B2 - Optical recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an optical recording medium, and more specifically, at least a metal reflection film and a light transmission layer are formed on one main surface of a substrate, and light is incident from the light transmission layer side to perform recording and / or reproduction. The present invention relates to an optical recording medium.
[0002]
[Prior art]
  In a conventional optical recording medium, for example, as shown in FIG. 24, a concavo-convex pattern such as pits and grooves indicating information signals is formed on at least one main surface on a light-transmitting substrate 51 formed by injection molding. The metal reflection film 52 and the protective film 53 are sequentially formed on the uneven pattern forming surface. In such an optical recording medium 50, light is incident through the objective lens 54 from the surface 51a of the surface of the substrate 51 on which the protective film 53 is not formed, and information signals are recorded and / or reproduced. Is called.
[0003]
  By the way, as a method for realizing further high-density recording of the optical recording medium, a method is proposed in which the numerical aperture of the objective lens of the optical pickup is increased to reduce the spot diameter of the reproduction light, and recording is performed in accordance with this. Has been.
[0004]
  In the optical recording medium using this method, in order to increase the numerical aperture of the objective lens, it is necessary to reduce the thickness of the substrate through which the reproduction light is incident and transmitted. This is because when the numerical aperture of the objective lens is increased, an allowable amount of an angle (hereinafter referred to as a tilt angle) at which the disk surface deviates from the vertical with respect to the optical axis of the optical pickup is reduced. This is because it is easily affected by the aberration due to the thickness of the substrate. Accordingly, in the above-described magneto-optical recording medium, the thickness of the substrate is made as thin as possible so as to minimize the influence of aberration due to the thickness of the substrate.
[0005]
[Problems to be solved by the invention]
  By the way, it seems that further higher recording density will be required in the future, and it is necessary to make the substrate thinner. Therefore, as shown in FIG. 25, a metal reflection film 62 and a light transmission layer 63 are sequentially formed on a substrate 61 having a concavo-convex pattern formed on one main surface 61b, and light is incident from the light transmission layer 63 side. An optical recording medium 60 for recording and / or reproducing information signals has been proposed. In this optical recording medium 60, it is possible to cope with an increase in the numerical aperture of the objective lens by making the light transmission layer 63 thinner.
[0006]
  By the way, also in this optical recording medium 60, information is recorded and / or reproduced while the central portion thereof is supported by the support member and rotated in the in-plane direction.
[0007]
  Specifically, as shown in FIG. 25, the optical recording medium 60 has a central hole 61a formed at the center thereof, and a first hole disposed on a turntable (not shown) via the central hole 61a. The clamp member 110 and a disk-like metal-like second clamp member 111 installed in the drive are sandwiched and supported in the thickness direction.
[0008]
  The first clamping member 110 has a bottomed cylindrical shape with a size that fits into the center hole 61a, and has a shape having a flange on the opening end side. A part of the optical recording medium 60 is placed on the collar portion with the bottomed cylindrical portion fitted into the center hole 61a. At this time, a magnet 112 is disposed in the cavity of the first clamp member 110, and the optical recording medium 60 is sandwiched in the thickness direction and supported by the magnetic force attracted by the magnet 112 and the second clamp member 111. And clamped. Here, a positioning pin 113 is attached to a substantially central portion of the bottom of the first clamp member 110. In addition, a hole that fits the positioning pin 113 is formed at the approximate center of the second clamp member 111. That is, the positioning pin 113 penetrates a predetermined substantially central portion of the second clamp member 111 and connects the first clamp member 110 and the second clamp member 111. The second clamp member 111 is attached to the drive via a disk loading mechanism (not shown).
[0009]
  Here, in order to support the optical recording medium 60 by the support member, the light transmission layer 63 side is placed on the first clamp.TheA clamping surface 64 is formed on the circumferential side of the center hole 61a as a mounting surface on the flange portion of the member 110.
[0010]
  Therefore, as described above, in the optical recording medium at the time of clamping, since the surface of the light transmission layer becomes a clamping region, the surface property of the light transmission layer significantly affects the clamping state.
[0011]
  For example, as shown in FIG. 26, in an optical recording medium 70 in which a metal reflective film 72 and a light transmission layer 73 are laminated on a substrate 71, a vertical projection 73a is formed on the light transmission layer 73. In addition, the optical recording medium 70 itself is tilted to cause a skew, resulting in large surface blurring.
[0012]
  Further, as shown in FIG. 27, in an optical recording medium 80 in which a metal reflective film 82 and a light transmission layer 83 are sequentially laminated on a substrate 81, lateral projections 73a and 73b toward the center hole of the light transmission layer 83 are provided. If formed, large eccentricity will occur.
[0013]
  If the surface property of the light transmission layer is not preferable, the optical recording medium itself is tilted and skew or eccentricity occurs, so that surface blurring increases or the optical recording medium surface shifts with respect to the optical axis. End up. As a result, there is a problem that coma aberration occurs in the recording / reproducing signal and the signal characteristics deteriorate.
[0014]
  Therefore, the present invention has been proposed in view of the conventional situation, and has a light transmission layer on at least one main surface of the substrate, and recording and / or reproduction is performed by making light incident from the light transmission layer side. An object of the present invention is to provide an optical recording medium in which the eccentricity and the surface blur are small in the optical recording medium to be performed, the recording / reproducing characteristics are improved, and the recording medium can cope with high density recording.
[0015]
[Means for Solving the Problems]
  In the optical recording medium according to the present invention completed to achieve the above-described object, a metal reflective film and a light transmission layer are sequentially formed on at least one main surface side of a disk-shaped substrate, and from this light transmission layer side. This is an optical recording medium on which recording and / or reproduction is performed by entering light and having a clamping region supported by a support on the inner peripheral side of the substrate.
[0016]
  In particular, the optical recording medium according to the present invention has a height of 0.1 mm in the clamping area.
No more protrusionsAt the same time, the inner periphery of the light transmission layer that becomes the clamping region does not contact the clamp member.It is characterized by this.
[0017]
  Here, a center hole is formed at the center of the substrate, the light transmission layer has an annular shape centering on the center hole, and the inner diameter of the light transmission layer is larger than the diameter of the center hole. Have.
[0018]
  In the optical recording medium according to the present invention configured as described above, since there are no protrusions having a height of 0.1 mm or more in the clamping area, the optical recording medium is prevented from being shaken. An angle deviating from a direction perpendicular to the optical axis (hereinafter referred to as a tilt angle) can be reduced, and coma generated during recording and reproduction can be suppressed.
[0019]
  Further, in the optical recording medium according to the present invention, by making the inner diameter of the light transmission layer larger than the diameter of the central hole formed in the substrate, the contact with the inner peripheral portion of the light transmission layer that is particularly prone to protrusion is minimized. Since clamping can be performed while suppressing, surface blurring of the optical recording medium can be suppressed, and coma aberration generated during recording and reproduction can be suppressed.
[0020]
  In the optical recording medium according to the present invention,The clamp region is formed by a convex portion formed on the substrate, and a concave portion having a depth of at least 0.1 mm is formed around the convex portion, and the concave-convex signal pattern, the metal reflection film, the thickness of 0.1 mm are formed in the concave portion. Forming a light transmission layer made of a 1 mm disc-shaped sheet;By not forming the light transmission layer in the clamping region, the clamping of the optical recording medium is performed not on the light transmission layer but on the molded substrate. Usually, the substrate is formed by means such as injection molding, but the substrate thus formed has a smooth surface. That is, in the optical recording medium according to the present invention as described above, clamping is performed on a smooth substrate, so that the optical recording medium can be prevented from shaking and coma occurring during recording and reproduction can be suppressed.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0022]
  As an optical recording medium to which the present invention is applied, a read-only optical recording medium is exemplified below, but an optical recording medium capable of recording / reproducing such as a magneto-optical recording medium may be used.
[0023]
  FIG. 1 is a sectional view showing a state in which an optical recording medium 1 to which the present invention is applied is clamped by a clamp member 100.
[0024]
  As shown in FIG. 1, an optical recording medium 1 to which the present invention is applied has a metal reflection film 3 and a light transmission layer 4 sequentially formed on a substrate 2 having an uneven signal pattern formed on the surface. In the optical recording medium 1, light is incident from the light transmission layer 4 side through the objective lens 5 to reproduce the information signal.
[0025]
  As shown in FIG. 1, the substrate 2 has a concavo-convex pattern composed of a groove-shaped concave portion 2 a and a hill-shaped convex portion 2 b. And this recessed part 2a and the convex part 2b are a signal pattern. As a material of the substrate 2, polycarbonate resin or methacrylic resin is mainly used. Furthermore, a modified polycarbonate resin is used as a material having good thermal characteristics. As other materials, plastic materials such as acrylic resin, polyolefin resin, and epoxy resin are used.
[0026]
  As a material of the metal reflection film 3, a metal material such as Al, Au, Ag, or the like is used. In particular, from the viewpoint of reflection characteristics, it is preferable to use a material containing at least Al. The metal reflective film 3 is formed by sputtering the above-described material by either ion beam sputtering or magnetron sputtering.
[0027]
  The light transmitting layer 4 is formed by applying an ultraviolet curable resin (hereinafter referred to as UV resin) by a spin coating method or the like and curing it with ultraviolet rays. Moreover, the thickness of the light transmission layer 4 is preferably about 10 μm to 177 μm, for example. The thickness range of the light transmission layer 4 is, for example, from −5.26 (λ / NA 4) μm to +5, where λ is the wavelength of light incident on the optical recording medium 1 and NA is the numerical aperture of the objective lens 5. .26 (λ / NA 4) μm is preferable.
[0028]
  Further, as schematically shown in FIG. 2, the optical recording medium 1 has a clamping area 6 supported by a support on the inner peripheral side, and an information signal is recorded and reproduced in an annular shape outside the clamping area 6. And an information recording area 7 to be performed.
[0029]
  FIG. 3 is a diagram showing a clamping area of the optical recording medium 1 to which the present invention shown in FIG. 1 is applied.
[0030]
  In particular, as shown in FIG. 3, the optical recording medium 1 to which the present invention is applied has no protrusion 8 having a height of 0.1 mm or more on the clamping region 6.
[0031]
  Therefore, in the optical recording medium 1 to which the present invention is applied, even when the protrusion 8 is present on the clamping area 6, the height of the protrusion 8 is limited to a predetermined value or less, and the surface property of the clamping area 6 is controlled. By doing so, surface blurring of the optical recording medium 1 during clamping can be suppressed. As a result, the tilt angle of the optical recording medium 1 can be reduced, and coma aberration that occurs during recording and reproduction can be suppressed.
[0032]
  Therefore, according to the optical recording medium 1 to which the present invention is applied, the recording / reproducing characteristics can be improved and high-density recording can be effectively realized.
[0033]
  As described above, even when the protrusion having a height of 0.1 mm or more does not exist, that is, when the protrusion 8 exists in the clamping region 6, the height is 0.1 mm or less to suppress the surface blur. It is effective for the following reasons.
[0034]
  First, as a case where the surface shake is the largest, a case where the protrusion 8 as shown in FIG. 3 is present on the inner peripheral surface of the clamping region 6 will be taken as an example. The surface shake at this time is defined based on the tilt angle as described in detail below.
[0035]
  Usually, in the case of a read-only optical disc having a diameter of about 120 mm, the clamping area is in the range of 26 mm to 33 mm in diameter. In the case of a large-capacity optical disk having the same size as the optical disk and a recording density of 6 to 8 times, the clamping area is in the range of 22 mm to 33 mm in diameter. Accordingly, it is preferable that the clamping region 6 of the optical recording medium to which the present invention is applied is a region having a diameter in the range of 22 mm to 33 mm.
[0036]
  In the optical recording medium 1, when there is a phenomenon (hereinafter referred to as tilt) that is deviated from the direction perpendicular to the optical axis, coma aberration occurs in the recording / reproducing signal and signal characteristics deteriorate.
[0037]
  Factors for the tilt include a warp of the optical recording medium alone, a tilt of the bearing of the player, and a surface shake at the time of clamping. When designing the optical recording medium 1, it is necessary to control the tilt angle caused by these factors. For example, the maximum tilt angle allowed as the tilt angle caused by the warp of the optical recording medium alone is 0.6 ° for the read-only optical disc and 0.4 ° for the large-capacity optical disc.
[0038]
  Therefore, in the next generation high-density optical disc system, the maximum tilt angle within the allowable range (hereinafter referred to as the maximum allowable tilt angle) among the tilt angles caused by the warp of the single disc is 0.4 °. It is considered that the maximum allowable tilt angle due to the tilt of the bearing of the player is 0.3 ° and the maximum allowable tilt angle due to the surface shake during clamping is 0.2 °.
[0039]
  From the above, assuming that θ is 0.2 ° in the maximum allowable tilt angle diagram when the surface deflection of the optical recording medium 1 is maximum, the maximum allowable value of the height of the protrusion 8 is calculated as shown below. be able to. Here, the tilt angle θ is maximized when the protrusion 8 is present on the innermost peripheral portion of the clamping region 6 as described above. Therefore, the height of the protrusion 8 at this time is assumed to be h.
[0040]
  The following approximate expression (1) is derived from h / (16.5 + 11) ≦ 0.2 / 360 × 2π.
[0041]
  h ≦ 0.1 (1)
  From the above formula (1), it is found that when the protrusion 8 is present in the clamping region 6, the height h of the protrusion 8 is preferably 0.1 mm or less. That is, it has been found that the clamping region 6 needs to have no protrusion having a height of 0.1 mm or more.
[0042]
  BookAs shown in FIG. 4, the optical recording medium 10 to which the invention is applied has a metal reflective film 12 and a light transmission layer 13 sequentially laminated on a substrate 11 and a center formed at the center of the substrate. The inner diameter of the central hole 13a in the light transmitting layer 13 having an annular shape is larger than the diameter of the hole 11a.Is formed.Here, the light transmission layer 13 has an annular shape with a center hole 11 a formed in the substrate 11 as a center.
[0043]
  As described above, the optical recording medium 10 has the inner diameter 13a of the light transmission layer 13 larger than the inner diameter 11a of the substrate. Since pinging can be performed, surface blurring and eccentricity of the optical recording medium 10 can be suppressed, and coma generated during recording and reproduction can be suppressed.
[0044]
  In other words, it is possible to avoid the phenomenon that the protrusions 73a and 73b as shown in FIG.
[0045]
  In addition, it becomes a reference example of the present inventionAs the optical recording medium 20, as shown in FIG.
22 and a light transmission layer 23 are sequentially laminated, and the clamping region 21
The light transmission layer 23 is not formed on a.At this time, no protrusion having a height of 0.1 mm or more is present on the substrate 21 which becomes the clamping region 21a.
[0046]
  As described above, the optical recording medium 20 is not affected by the surface property of the light transmission layer 23 because the light transmission layer 23 is not formed in the clamping region 21 a and thus clamping is performed on the substrate 21. Further, the surface blurring of the optical recording medium 20 is suppressed, and coma aberration that occurs during recording and reproduction can be suppressed.
[0047]
  Also,Others to which the present invention is appliedAs shown in FIG. 6, the optical recording medium 30 has a metal reflective film 32 and a light transmission layer 33 sequentially stacked on a substrate 31, and a convex portion 31 a is formed at a substantially central portion of the substrate 31. There are also examples in which the convex portion 31a is used as a clamping region.
[0048]
  Here, the light transmission layer 33 is not formed on the convex portion 31a, and there is no projection having a height of 0.1 mm or more. And this convex part 31a is the 1st clan.TheIt is mounted on the collar part of the member 110, and this mounting surface is used as a clamping region.
[0049]
  As described above, in the optical recording medium 30, since the convex portion 31 a of the substrate 31 is used as a clamping region, clamping is performed on the convex portion 31 a of the substrate 21, thereby affecting the surface property of the light transmission layer 33. Therefore, the surface blur of the optical recording medium 20 can be suppressed, and coma aberration generated during recording and reproduction can be suppressed.
[0050]
  In addition, it becomes a reference example of the present inventionAs shown in FIG. 7, as the optical recording medium 40, a metal reflective film 42 is formed on a substrate 41, and a sheet-like light transmission layer 44 is opposed to the metal reflective film 42 via an adhesive resin 43. What is formed is also mentioned. Here, the sheet-like light transmission layer 44 is bonded to the metal reflective film 42 with an adhesive resin 43.
[0051]
  ThisAs in FIG. 6, the optical recording medium 40 has a convex portion 41 a formed at a substantially central portion of the substrate 41, and this convex portion 41 a is a first clamp.TheIt is mounted on the collar part of the member 110, and this mounting surface is used as a clamping region.
[0052]
  As described above, in the optical recording medium 40, since the convex portion 41a of the substrate 41 is used as a clamping region, chucking is performed on the convex portion 41a of the substrate 41. It is possible to suppress coma aberration that occurs during recording and reproduction. Moreover, since the sheet-like light transmission layer 44 is bonded to the optical recording medium 40, the surface property of the light transmission layer 44 is preferable, and the recording / reproduction characteristics are improved.
[0053]
  Below, the manufacturing method of the optical recording media 20 and 40 mentioned above is demonstrated in detail with reference to drawings.
[0054]
  FigureAs shown in 5Reference example of the present inventionThe optical recording medium 20 is manufactured as follows.
[0055]
  First, as shown in FIG. 8, a substrate 21 having a concavo-convex signal pattern on one principal surface 21b is formed by injection molding. Then, as shown in FIG. 9, a metal reflection film 22 is formed on one main surface 21b on which the signal pattern of the substrate 21 is formed by using a sputtering method.
[0056]
  Next, as shown in FIG. 10, a disk-shaped disc made of polycarbonate having a diameter of about 35 mm and a thickness of 0.1 mm is formed in the substantially central portion of the substrate 21 on which the metal reflective film 22 is formed, that is, in the portion 21a serving as a clamping region. A seat 24 is installed. Here, the thickness of the sheet 24 may be 0.1 mm or less.
[0057]
  Next, as shown in FIG. 11, an ultraviolet curable resin (hereinafter referred to as UV resin) 25 is dropped onto a substantially central portion 21 a where the sheet 24 is installed.
[0058]
  Next, as shown in FIG. 12, the substrate 21 is rotated, and the UV resin 25 is uniformly formed on the entire surface of the substrate to a desired thickness.
[0059]
  Next, as shown in FIG. 13, the UV resin 25 formed on the entire surface of the substrate is irradiated with ultraviolet rays from the UV lamp 101 to cure the UV resin 25.
[0060]
  Next, as shown in FIG. 14, the UV resin 25 formed on the entire surface of the substrate is trimmed to form the light transmission layer 23 with the same thickness as the sheet 24.
[0061]
  Finally, as shown in FIG. 15, by using a punching machine, high pressure air is blown from the substrate 21 to the light transmission layer 23 in the direction of arrow A in the figure to push up the sheet 24, and the sheet 24 is peeled off. The optical recording medium 20 is manufactured.
[0062]
  The optical recording medium 20 as shown in FIG. 5 can be manufactured by the manufacturing method described above.
[0063]
  In order to more stably install the sheet on the substrate 21, as shown in FIG. 16, a sheet 26 having a convex portion 26a formed at a substantially central portion may be used.
[0064]
  Further, in order to more stably install the sheet on the substrate 21, as shown in FIG. 17, a recess 27a that can be joined to the sheet 28 when the substrate 27 is molded by injection molding may be provided. . In this case, the shape of the substrate 27 is different from the shape of the substrate 21 of the optical recording medium 20 as shown in FIG.,lightThe point which controls the surface property of a permeable layer has an effect similar to FIG.
[0065]
  AlsoThe figureThe optical recording medium 40 as shown in 7 is manufactured as follows.
[0066]
  First, as shown in FIG. 18, a convex portion 41a is formed from the center to a diameter of 35 mm by injection molding, and a concave-convex signal pattern is formed from the diameter of 35 mm to the outer peripheral portion. The depth d of the concave portion is 0.1 mm. The board | substrate 41 is shape | molded so that it may become the above.
[0067]
  Next, as shown in FIG. 19, a metal reflective film 42 is formed on the signal pattern of the substrate 41 by sputtering.
[0068]
  Next, as shown in FIG. 20, a disk-like sheet 44 trimmed so as to have a center hole diameter of 35.1 mm, an outer diameter of 119 mm, and a thickness of 0.1 mm is prepared. Then, after dropping the UV resin 45 on the metal reflective film 42, the sheet 44 is disposed on the UV resin 45.
[0069]
  Next, as shown in FIG. 21, the substrate 41 on which the sheet 44 is disposed is rotated to form the UV resin 45 on the entire surface of the metal reflective film 42. At this time, the thickness of the UV resin 45 becomes uniform to 5 μm.
[0070]
  Finally, as shown in FIG. 22, the entire surface of the sheet 44 is irradiated with ultraviolet rays from the UV lamp 102 to cure the UV resin 45, and the sheet 44 and the substrate 41 are bonded to manufacture the optical recording medium 40. To do.
[0071]
  The optical recording medium 40 as shown in FIG. 7 can be manufactured by the manufacturing method described above.
[0072]
  It is preferable that the optical recording media 20 and 40 manufactured as described above are formed by sputtering, for example, SiN so as to have a thickness of 100 nm on the light transmission layers 23 and 43. Thereby, the signal surface is hard and smoothed, and the recording / reproducing characteristics can be further improved.
[0073]
  Moreover, it is preferable to form Al on the surface opposite to the light transmitting layers 23 and 43 on the surfaces of the substrates 21 and 41 so as to have a thickness of 30 nm. Thereby, the warp of the optical recording medium due to moisture absorption can be reduced.
[0074]
  It should be noted that the light transmission layer as described above can be formed on the signal patterns on both sides of the optical recording medium having the signal patterns on both sides of the substrate.
[0075]
  Moreover, it has the structure as described aboveLightThe recording media 10, 20, 30, and 40 may be used together.
[0076]
  As the clamping member, as shown in FIG. 23, the first clamping member 200 has a vertical portion 201, and the thickness of the vertical portion 201 is substantially the same as the thickness of the light transmission layer 4. Even a shape is preferable. In this case, since the surface blur is due to the surface property of the inner diameter side surface 2c of the smooth substrate 2, it does not depend on the surface property of the light transmission layer 4, and can be within an allowable range.
[0077]
【The invention's effect】
  As described above in detail, in the optical recording medium according to the present invention, since there is no protrusion having a height of 0.1 mm or more in the clamping region, the optical recording medium is prevented from being shaken and the tilt angle is reduced. As a result, coma aberration occurring during recording and reproduction can be suppressed. Therefore, according to the optical recording medium of the present invention, the recording and / or reproducing characteristics can be improved, and it is possible to sufficiently cope with high density recording.
[0078]
  Further, in the optical recording medium according to the present invention, the inner diameter of the annular light transmission layer is larger than the diameter of the central hole formed in the substrate, so that it is in contact with the inner peripheral portion of the light transmission layer particularly prone to protrusion. Therefore, it is possible to suppress the surface blur of the optical recording medium, and it is possible to suppress coma aberration that occurs during recording and reproduction. Therefore, according to the optical recording medium of the present invention, the recording / reproducing characteristics can be improved, and it is possible to sufficiently cope with the high density recording, and the yield in the manufacturing process can be improved.Furthermore, since the height of the clamping region is not different from the height of the light transmitting layer surface, positioning in the height direction can be performed accurately.
[0079]
  In the optical recording medium according to the present invention,The clamping region is formed by the convex portions formed on the substrate,By not forming the light transmission layer in the clamping region, the clamping of the optical recording medium is performed not on the light transmission layer but on the molded substrate. Usually, since the substrate molded by injection molding has a smooth surface, in the optical recording medium according to the present invention as described above, since the clamping is performed on the substrate, the surface blurring of the optical recording medium is suppressed, It is possible to suppress coma aberration that occurs during recording and reproduction. As a result, recording / reproduction characteristics can be improved, high-density recording can be sufficiently handled, and the manufacturing process can be simplified and the yield can be improved to improve production efficiency. it can.Furthermore, since the difference between the surface height of the light transmission layer and the height of the clamping portion is small, it can be positioned within a height range that is easily accessible when clamped.
[Brief description of the drawings]
FIG. 1 shows the present invention.A reference exampleIt is sectional drawing which shows an example of an optical recording medium.
[Figure 2]lightIt is a perspective view which shows an example of a recording medium.
FIG. 3 is a cross-sectional view of an essential part showing an example of a protrusion existing in a clamping region.
FIG. 4 is an optical recording medium to which the present invention is applied.the body'sIt is principal part sectional drawing which shows an example.
FIG. 5 shows the present invention.A reference exampleIt is principal part sectional drawing which shows another example of an optical recording medium.
FIG. 6 is a cross-sectional view of the main part showing another example of an optical recording medium to which the present invention is applied.
FIG. 7A reference exampleIt is principal part sectional drawing which shows another example of an optical recording medium.
FIG. 8A reference exampleIt is a schematic diagram explaining the mode of the shaping | molding board | substrate in an example of the manufacturing method of an optical recording medium.
FIG. 9A reference exampleIt is a schematic diagram explaining a mode that a metal reflective film is formed on a board | substrate in an example of the manufacturing method of an optical recording medium.
FIG. 10 shows the present invention.A reference exampleIt is a schematic diagram explaining a mode that a sheet | seat is installed in a clamping area | region in an example of the manufacturing method of an optical recording medium.
FIG. 11 shows the present invention.A reference exampleIt is a schematic diagram explaining a mode that UV resin is dripped in an example of the manufacturing method of an optical recording medium.
FIG. 12 shows the present invention.A reference exampleIt is a schematic diagram explaining how a UV resin is uniformly formed by rotating an optical recording medium in an example of a method for manufacturing an optical recording medium.
FIG. 13 shows the present invention.A reference exampleIt is a schematic diagram explaining a mode that UV resin in an example of the manufacturing method of an optical recording medium is hardened with a UV lamp.
FIG. 14 shows the present invention.A reference exampleIt is a schematic diagram explaining how a UV resin is trimmed to form a light transmission layer in an example of a method for manufacturing an optical recording medium.
FIG. 15 shows the present invention.A reference exampleIt is a schematic diagram explaining a mode that a sheet | seat is peeled in an example of the manufacturing method of an optical recording medium.
FIG. 16 shows the present invention.A reference exampleIt is a schematic diagram which shows another example of the sheet | seat used in an example of the manufacturing method of an optical recording medium.
FIG. 17 shows the present invention.A reference exampleIt is a schematic diagram which shows another example of the board | substrate of an optical recording medium.
FIG. 18 is a schematic diagram showing a state of a molded substrate in another example of a method for producing an optical recording medium to which the present invention is applied.
FIG. 19 is a schematic diagram for explaining how a metal reflective film is formed on a substrate in another example of a method of manufacturing an optical recording medium to which the present invention is applied.
FIG. 20 is a schematic diagram for explaining a state in which a disc-shaped sheet is disposed in a clamping region and bonded by a UV resin in another example of a method for manufacturing an optical recording medium to which the present invention is applied.
FIG. 21 is a schematic diagram illustrating a state in which an optical recording medium on which a sheet is arranged is rotated in another example of a method for manufacturing an optical recording medium to which the present invention is applied.
FIG. 22 is a schematic diagram for explaining how a UV resin is cured by a UV lamp in another example of a method for producing an optical recording medium to which the present invention is applied.
FIG. 23 is a schematic view of the relevant part showing another example of a clamping member used in an optical recording medium to which the present invention has been applied.
FIG. 24 is a cross-sectional view showing an example of a conventional optical recording medium.
FIG. 25 is a cross-sectional view showing a state in which an optical recording medium is clamped.
FIG. 26 is a cross-sectional view of an essential part for explaining an example of an optical recording medium having protrusions formed on a light transmission layer.
FIG. 27 is a cross-sectional view of an essential part for explaining another example of the optical recording medium in which a projection is formed on the light transmission layer.
[Explanation of symbols]
  1, 10, 20, 30, 40 Optical recording medium, 2, 11, 21, 31, 41 substrate, 3, 12, 22, 32, 42 Metal reflective film, 4, 13, 23, 33, 43 Light transmission layer, 6 Clamping area, 8 protrusions

Claims (2)

A metal reflection film and a light transmission layer are sequentially formed on at least one main surface side of the disk-shaped substrate, and recording and / or reproduction is performed by irradiating light from the light transmission layer side, and the inner periphery of the substrate. In an optical recording medium having a clamping region supported by a clamp member on the side,
A central hole is formed at the center of the substrate, and the light transmission layer has an annular shape centering on the central hole, and a protrusion having a height of 0.1 mm or more exists on the inner peripheral side of the annular shape. The light transmission layer has an inner diameter larger than the diameter of the center hole, and the inner periphery of the light transmission layer does not contact the clamp member during clamping. Optical recording medium. A metal reflection film and a light transmission layer are sequentially formed on at least one main surface side of the disk-shaped substrate, and recording and / or reproduction is performed by irradiating light from the light transmission layer side, and the inner periphery of the substrate. In an optical recording medium having a clamping region supported by a clamp member on the side,
A convex portion having a center hole is formed in the central portion of the substrate, the clamping region is formed by the convex portion, and a concave portion having a depth of at least 0.1 mm is formed around the convex portion. An optical recording medium , wherein a concave and convex signal pattern, a metal reflection film, and a light transmission layer made of a disc-shaped sheet having a thickness of 0.1 mm are sequentially formed in the recess .

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