JPH07287868A - Disk, manufacture thereof and reproducing device therefor - Google Patents

Abstract

PURPOSE:To provide a disk usable for a storage medium of stereoscopic dynamic images in the MPEG(MOTION PICTURE CODING EXPERT GROUP) system, etc., capable of reproducing them easily and easy to massproduce. CONSTITUTION:Recording tracks 6a and 6b are concurrently molded by two opposing stampers C and D and further two reflection layers 3a and 3b are formed respectively on two sides of a disk base section 1. By these procedures, concurrent formation of recording tracks and reflecting layers are realized and a disk 10 both sides of which are recorded with information is easily formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium such as an optical disc on which information is recorded, a manufacturing method thereof, and a reproducing apparatus thereof.

[0002]

2. Description of the Related Art With the recent increase in the amount of information, rationalization of paperwork, and paperlessness, documents such as documents and drawings are optically read, and the read image information is compressed to record a large-capacity recording medium such as an optical disk. Has been put into practical use, and an information file device capable of storing, storing, and retrieving image information recorded on the recording medium as required and displaying or printing it has been put into practical use (for example, "Optical Disk Filing System by Sanyo Electric Co., Ltd .; SOF-FS21 '').

Furthermore, MPEG (Motion Picture Coding)
Expert Group; ISO 11172 (MPEG1), ISO 13818 (MPEG2))
In a compression method for performing compression using intra-image unit compression such as image compression and inter-image unit compression by referencing another image, it can also be used as a storage medium for a stereoscopic moving image that decodes and reproduces compression-encoded stereoscopic moving image data. It is used.

[0004]

However, when used as a storage medium for a stereoscopic moving image, if the left and right images are recorded alternately on one recording track, the interval between frames becomes long and the image information The density becomes low and good image quality cannot be secured. Therefore, two optical disks or the like are used to read out the left and right images from both of the synchronized optical disks. However, it is necessary to completely synchronize the rotations of both optical discs, and the control needs to synchronize the rotation control and tracking control of both optical discs, which makes the reproducing apparatus expensive.

Therefore, a recording medium which can be used as a storage medium for stereoscopic moving images of the MPEG system and the like, which can be easily reproduced and which is suitable for mass production, and a manufacturing method thereof, and a reproducing apparatus thereof are provided. Is an issue.

[0006]

According to another aspect of the present invention, there is provided a storage medium in which a recording track is simultaneously formed on both surfaces of a disk substrate portion by two stampers facing each other in a disk for recording information. A reflective layer is formed on both surfaces of the formed disk substrate portion.

A storage medium according to a second aspect of the present invention is such that the recording tracks on both sides of the disk substrate portion of the first aspect are spirals in mutually opposite directions.

According to a third aspect of the present invention, the recording medium on both sides of the disk substrate portion of the first aspect has spiral recording tracks in the same direction.

A storage medium according to a fourth aspect of the present invention is a storage medium in which the reflective layers on both sides of the disk substrate portion of the first aspect are total reflection layers.

According to a fifth aspect of the present invention, there is provided a storage medium in which the reflective layers on both sides of the disk substrate section according to the first aspect are semitransparent films.

According to a sixth aspect of the present invention, there is provided a storage medium, wherein the translucent films on both surfaces of the disk substrate portion of the fifth aspect are provided with a transmittance of 30 to 60.
It is a percentage.

A method of manufacturing a storage medium according to claim 7 is
A step of forming a disk substrate portion for simultaneously forming recording tracks on both sides by two stampers facing each other, a step of forming a reflective layer on both sides of the disk substrate portion on which the recording tracks are formed, and the disk And a protective layer forming step of forming protective layers on the surfaces of the reflective layers on both sides of the substrate portion.

A reproducing apparatus for a storage medium according to an eighth aspect,
A recording medium in which recording tracks are simultaneously formed on both surfaces of a disk substrate portion by two stampers facing each other, and a reflective layer is formed on both surfaces of the disk substrate portion on which the recording tracks are formed. The reflective layer is a semi-transparent film, and the simultaneously recorded information is read from the back surfaces of the two.

[0014]

According to the first aspect of the present invention, in a disc for recording information, recording tracks are simultaneously formed on both sides of the disc substrate portion by two stampers facing each other, and the recording tracks are reflected on both sides of the disc substrate portion. A layer is formed, and at the same time, recording tracks can be formed on the front and back.

According to a second aspect of the present invention, since the recording tracks on both sides of the disk substrate section of the first aspect are spirals in opposite directions, front and back reproduction can be performed simultaneously.

According to the third aspect of the present invention, since the recording tracks on both sides of the disk substrate section of the first aspect are spirals in the same direction, the front and back can be continuously reproduced.

According to a fourth aspect of the present invention, the reflection layers on both sides of the disk substrate portion of the first aspect are total reflection layers.
Information can be read from and reproduced from recording tracks on the front sides of each other.

According to a fifth aspect of the present invention, the reflective layers on both sides of the disk substrate portion of the first aspect are semitransparent films.
Information can be read and reproduced from the recording tracks on the back side of each other.

According to a sixth aspect of the present invention, since the translucent films on both surfaces of the disk substrate portion of the fifth aspect have a transmittance of 30 to 60%, reflection noise is reduced and recording tracks on the backside of each other are reduced. Can read and reproduce information.

According to a seventh aspect of the present invention, a step of forming a disk substrate portion for simultaneously forming recording tracks on both surfaces is performed by two stampers facing each other, and a reflective layer is formed on both surfaces of the disk substrate portion on which the recording tracks are formed. Since the storage medium is manufactured by the step of forming the reflective layer and the step of forming the protective layer on the surfaces of the reflective layers on both surfaces of the disk substrate, the recording tracks on the front and back sides can be formed at the same time.

According to another aspect of the present invention, in the reproducing apparatus, recording tracks are simultaneously formed on both surfaces of the disk substrate portion by two stampers facing each other, and reflective layers are formed on both surfaces of the disk substrate portion on which the recording tracks are formed. In this recording medium, the reflective layers on both sides of the disc substrate are semi-transparent films, and the recorded information is read simultaneously from the back surfaces of each other. You can also do it.

[0022]

EXAMPLES Hereinafter, a recording medium of the present invention and a method for manufacturing the same,
An example of the reproducing apparatus will be described.

1 to 6 are explanatory views showing a recording medium and a manufacturing method thereof according to an embodiment of the present invention.

FIG. 1 is a cross-sectional view for explaining a recording medium molding process according to an embodiment of the present invention, FIG. 2 is a cross-sectional view in which a center hole of the recording medium molded according to FIG. 1 is formed, and FIG.
FIG. 4 is a sectional view in which a reflective layer is formed on the recording medium, and FIG. 4 is a sectional view in which a protective layer is formed on the recording medium in FIG. 5 is a plan view of a spiral in which recording tracks on both sides of a recording medium according to an embodiment of the present invention are opposite to each other. FIG. 6 is a plan view of both sides of a recording medium according to an embodiment of the present invention on which recording tracks on both sides are in the same direction. It is a top view of the spiral of. In these figures, the thickness, recording track, etc. are exaggerated from the actual state.

In FIG. 1, an upper mold A and a lower mold B are molding dies for an optical disk, and an internal space of the upper mold A and the lower mold B accommodates an upper nickel (Ni) stamper C and a lower nickel stamper D. The thickness of the disk substrate portion 1 is set so that the reflective surface of the optical disk can be formed when the disk is molded in this state. The upper nickel stamper C and the lower nickel stamper D are accurately set to the upper mold A or the lower mold B.

A synthetic resin is injected from an injection port E into the internal space of the mold formed by the upper mold A and the lower mold B. This corresponds to the molding process of the disk substrate portion 1 of this embodiment.

In FIG. 2, the disk substrate 1 is molded by the injection molding method shown in FIG.
Is drilled. The disk substrate portion 1 is made of an acrylic resin, a polycarbonate resin, a polyvinyl chloride resin, or the like, and is a synthetic resin having a light-transmitting property that transmits laser light. This disc substrate portion 1 corresponds to a substrate of a conventional optical disc, has a form of a disc body having a center hole 2, and has a pair of front and back surfaces 1a and 1b facing each other on the upper and lower sides, that is, the front and back sides. is doing. The center hole 2 is a portion that is directly or via a clamping hub or the like attached to a spindle that is rotationally driven by a motor.

In FIG. 3, the reflective layer 3a on the upper surface and the reflective layer 3b on the lower surface of the disk substrate 1 are, in the present embodiment, made of a vapor-deposited film or sputtered film of a metal such as aluminum in which phase pits are formed. There is. Specifically, the reflective layers 3a and 3b are formed by forming pits on the surface of the disk substrate portion 1 by a method such as injection molding and then depositing or sputtering a metal such as aluminum on the surface including the pits. . This is the reflection layer 3a of this embodiment,
This corresponds to the forming step of 3b.

In particular, in this embodiment, the reflective layers 3a and 3b on both sides of the disk substrate 1 are semitransparent films so that information can be read from the back sides of each other. Incidentally, the translucent film of the present example has a transmittance of 30% according to an experiment by the inventors.
The reflection noise is reduced, and information can be read from the recording tracks on the back side of each other. The translucent film can be used in the range of transmittance of 30 to 60%, and the most suitable characteristic was obtained in the range of transmittance of 40 to 50%.

In FIG. 4, a protective layer 4a shown by a solid line is formed on the upper surface of the reflective layer 3a on both surfaces of the disc substrate 1, and a protective layer 4b is formed on the lower surface of the reflective layer 3b.
Are configured. The protective layers 4a and 4b are the reflection layer 3
The protective layers 4a and 4b prevent the laser light incident on the disk substrate portion 1 from being reflected as such and returned to the optical pickup as noise. Also works as.

Further, the reflective layers 3 on both sides of the disk substrate portion 1
A protective layer 5a is formed on the upper surface of a by a broken line, and a protective layer 5b is formed on the lower surface of the reflective layer 3b. This protective layer 5
a and 5b, when the reflection layers 3a and 3b are totally reflected, the reflection layers 3a and 3b are read from both surfaces.
In order to adjust the transmission distance of the protective layer to about 1.2 mm,
The protective layer 5a, 5b is thickened to form the disk 10. It should be noted that this corresponds to the step of forming the protective layers 5a and 5b in this embodiment.

In the disk 10 constructed as described above, the recording tracks 6a formed on the reflection layer 3a and the recording tracks 6b formed on the reflection layer 3b of the disk substrate portion 1 are formed.
As shown in FIG. 5, the recording tracks 6a on the front and back sides are spirals in the same direction as viewed from above,
That is, it is a spiral in the same direction as seen from the top side, and conversely, if the top side of FIG. 5 is inverted to the bottom side, the spiral in the opposite direction, that is, the opposite of FIG. 5 seen from the top side is seen. It is a spiral of direction. In other words, the recording track 6a is formed in the left rotation direction on the upper surface of FIG. 5, and the recording track 6b is formed in the right rotation direction on the lower surface of FIG.
The recording tracks 6a and the recording tracks 6b on both sides formed on the reflective layer 3a are spirals in opposite directions.

In the case where the recording tracks 6a and the recording tracks 6b on both sides of this kind have a spiral shape in the opposite directions, for example, the upper surface is a recording area of an image corresponding to the right eye, and the lower surface is recording of an image corresponding to the left eye. It is suitable for reproduction in the case of a stereoscopic image such as a region.

Further, the disk 10 constructed as described above.
6, the recording tracks 7a formed on the reflection layer 3a and the recording tracks 7b formed on the reflection layer 3b of the disc substrate portion 1 are opposite to each other when the recording tracks 7a on the front and back sides are opposite to the recording tracks 7b as shown in FIG. A spiral in one direction, that is, a spiral in the opposite direction when viewed from above can be used. That is, the recording track 7a is formed on the upper surface of FIG. 6 in the counterclockwise rotation direction, and the recording track 7b is formed on the lower surface of FIG. 6 in the counterclockwise rotation direction. The recording track 7a and the recording track 7b have a spiral shape in the same direction.

In the case where the recording tracks 7a and the recording tracks 7b on both sides of this kind are spiral-shaped in the same direction as each other, for example, after the upper surface is reproduced, the reproduction can be continued from the lower surface by the same rotation, and the reproduction can be continued. It is suitable for the case of performing the output.

Next, a reproducing apparatus will be described for the case where the recording tracks on both sides shown in FIG. 5 are spirals in opposite directions, and for the recording tracks on both sides shown in FIG. 6 are spirals in the same direction. .

FIG. 7 is an overall block diagram of the reproducing apparatus for reproducing the recording tracks shown in FIG. 5 from the spiral storage medium in the opposite directions.

In FIG. 7, the disk 10 is, for example,
A CD-ROM signal is recorded in the CD format. The spindle motor 21 is a motor that drives the disk 10 to rotate, and is controlled to rotate by the spindle servo 22 to rotate the disk 10 at a constant speed. Also,
The spindle servo 22 moves the pickup 23R and performs focus control and tracking control of the pickup 23R according to a control command from a control circuit (not shown).

The Rch information corresponding to the right-eye information recorded on the back surface of the disc 10 is optically read by the pickup 23R. The read signal from the pickup 23R is input to the CDDA decoder 25R via the amplifier 24R, and the CDDA decoder 25R demodulates the data detected by the pickup 23R to perform error correction, and for information exceeding the error correction range, 1 1-bit correctness / incorrectness determination information cannot be generated for each byte (8 bits). The CD-ROM decoder 26R descrambles and demodulates it into a CD-ROM format. The MPEG decoder 27R decodes Rch image data that has been compression-encoded in the MPEG system (a compression system that performs compression using intra-image unit compression and inter-image unit compression by referring to another image).

The Lch information corresponding to the left-eye information recorded on the surface of the disk 10 is optically read by the pickup 23L, and the read signal from the pickup 23L is input to the CDDA decoder 25L via the amplifier 24L. CDDA decoder 25L is pickup 23
The data detected by L is demodulated, error correction is performed, and CD
-The ROM decoder 26L descrambles and demodulates to the CD-ROM format. Also, MP
The EG decoder 27L decodes the compression-encoded Lch image data in the MPEG system.

At this time, the pickup 23R and the pickup 23L move in the radial direction (center direction) of the disk 10 at the same speed. In particular, although the pickup 23R and the pickup 23L are shown at positions separated by 180 degrees in the drawing, when the present invention is carried out, the pickup 23R and the pickup 23L can be set at positions facing each other. In this case, it is easy to reduce the mechanical error between the two.

As described above, in the reproducing apparatus of this embodiment, the recording tracks 6a and 6b are simultaneously formed on both surfaces of the disk substrate portion 1 by the two stampers C and D facing each other, and the recording tracks 6a and 6b are formed. In the disc 10 in which the reflection layers 3a and 3b are formed on both sides of the formed disc substrate portion 1, the reflection layers 3a and 3b on both sides of the disc substrate portion 1 are semitransparent films, and information recorded simultaneously from the back surface of each other. Is read.

FIG. 8 is an overall block diagram of a reproducing apparatus for reproducing the recording tracks shown in FIG. 6 from the spiral storage medium in the same direction.

In FIG. 8, the disk 10 is, for example,
A CD-ROM signal is recorded in the CD format. The spindle motor 31 is a motor that drives the disk 10 to rotate, and is controlled to rotate by the spindle servo 32 to rotate the disk 10 at a constant speed. Also,
The spindle servo 32 moves the pickup 33U and performs focus control and tracking control of the pickup 33U according to a control command from a control circuit (not shown).

The upper surface information corresponding to the information recorded on the surface of the disk 10 is optically read by the pickup 33U. The read signal from the pickup 33U is input to the CDDA decoder 35 via the amplifier 34U and the switch 38, and the CDDA decoder 35 demodulates the data detected by the pickup 33U and performs error correction.
For information exceeding the error correction range, it is impossible to generate 1-bit correctness determination information per 1 byte (8 bits). The CD-ROM decoder 36 descrambles the bits and demodulates them into a CD-ROM format. Also, the MPEG decoder 37 decodes the image data that has been compression-encoded in the MPEG system (a compression system that performs compression using intra-image unit compression and inter-image unit compression by referring to another image).

When the pickup 33U optically detects the end of the upper surface information corresponding to the information recorded on the surface of the disk 10, the CD-ROM decoder 36 judges that the upper surface information has ended, and switches the switch 38. By switching the switch 38, the lower surface information recorded on the back surface of the disk 10 is optically read by the pickup 33D, and the read signal from the pickup 33D is the amplifier 34D and the switch 3.
Is input to the CDDA decoder 35 via
The compression-coded image data is decoded via the decoder 35, the CD-ROM decoder 36, and the MPEG decoder 37.

At this time, the pickup 33D picks up when the pickup 33U finishes detecting.
Detection is started and the disk 10 is sequentially moved in the radial direction. Especially, in the figure, the pickup 33U is placed at a position facing each other.
The pickup 33D and the pickup 33D are shown.
3D can be set at a position 180 degrees apart. In this case, it is easy to reduce the mechanical error between the two.

As described above, in the disk of this embodiment, the recording tracks 6a, 6b, 7a and 7b are simultaneously formed on both surfaces of the disk substrate 1 by the two stampers C and D facing each other, and the recording track 6a is formed. , 6b, 7a, 7b are provided with reflective layers 3a, 3b on both sides of the disk substrate 1, which can be the embodiment of claim 1.

In the disk of the above embodiment, the recording tracks 6a, 6b, 7a and 7b are simultaneously formed on both surfaces of the disk substrate 1 by the two stampers C and D facing each other in the disk 10 for recording information. Then, the disk substrate portion 1 on which the recording tracks 6a, 6b, 7a, 7b are formed
The reflective layers 3a and 3b are formed on both surfaces of the above, and at the same time, the recording tracks 6a, 6b, 7a and 7b can be formed on the front and back sides.

Therefore, at the same time, the recording tracks 6a, 6
Since the reflection layers 3a and 3b can be formed on both sides of the disc substrate portion 1 on which b, 7a and 7b are formed, one disc 10 is formed by joining two reflection layers on one side of the disc substrate portion on which recording tracks are formed. Since it is not formed, the disk 10 having information recorded on both sides can be easily formed.

Further, the disk of this embodiment has two opposing disks.
Recording tracks 6a and 6b are simultaneously formed on both surfaces of the disk substrate portion 1 by the individual stampers C and D, and reflective layers 3a and 3b are formed on both surfaces of the disk substrate portion 1 on which the recording tracks 6a and 6b are formed. In the disc 10, the recording tracks 6a and 6b on both sides of the disc substrate 1 are spirals in mutually opposite directions, so that the recording tracks 6a and 6b on the front and back sides can be reproduced at the same time. This can be the embodiment of claim 2.

In this type of embodiment, since the front and back recording tracks 6a and 6b can be reproduced at the same time, it is efficient to use them as a storage medium for obtaining different information such as a stereoscopic image and stereo at the same time and combining them. It can be controlled, and the cost of the reproducing apparatus can be reduced.

In the disk of this embodiment, the recording tracks 7a and 7b are simultaneously formed on both surfaces of the disk substrate 1 by the two stampers C and D facing each other, and the recording tracks 7a and 7b are formed. In the disk 10 in which the reflective layers 3a and 3b are formed on both surfaces of the substrate unit 1,
The recording tracks 7a and 7b on both sides of the disc substrate 1 are
Since the spirals are in the same direction as each other, the front and back can be continuously reproduced, and this can be the embodiment of claim 3.

Therefore, in this kind of embodiment, since the recording track 7b on the back side can be reproduced when the reproduction of the recording track 7a on the front side is completed, it is suitable for reproducing information for a continuous long time, Efficient control is possible and the cost of the reproducing device can be reduced.

Further, the discs of this embodiment have two opposing disks.
Recording stamps 6a, 6b, 7a, 7b are simultaneously formed on both sides of the disc substrate 1 by the individual stampers C, D, and reflected on both sides of the disc substrate 1 on which the recording tracks 6a, 6b, 7a, 7b are formed. In the disc 10 having the layers 3a and 3b formed, since the reflection layers 3a and 3b on both sides of the disc substrate portion 1 are total reflection layers, the reproduction of the front and back recording tracks 6a, 6b, 7a and 7b is simultaneously performed. You can This can be the embodiment of claim 4.

Therefore, in this embodiment, the protective layers 5a, 5a
Although it is necessary to make b thicker, since the front and back recording tracks 6a, 6b, 7a, 7b can be reproduced at the same time, different information such as stereoscopic images and stereos can be obtained at the same time and used as a storage medium for combining them. Efficient control is possible and the cost of the reproducing device can be reduced. Also, at the time when the reproduction of the recording track 7a on the front surface is completed,
Since the recording track 7b on the back surface can be reproduced, it is suitable for reproducing a long continuous information, efficient control is possible, and the cost of the reproducing device can be reduced.

In the disk of this embodiment, recording tracks 6a, 6b, 7a and 7b are simultaneously formed on both surfaces of the disk substrate portion 1 by two stampers C and D facing each other, and the recording tracks 6a, 6b and 7a are formed. , 7b are formed on both surfaces of the disk substrate portion 1 to form reflective layers 3a and 3b. The reflective layers 3a and 3b on both surfaces of the disk substrate portion 1 are semi-transparent films, and information recorded sequentially from the front and back surfaces is recorded. Since the reading is performed, the recording tracks 6a, 6b on the back side of each other,
Information can be read and reproduced from 7a and 7b, and this can be the embodiment of claim 5.

Therefore, in this embodiment, the protective layers 4a, 4a
It is not necessary to make b thick, and at the same time, recording tracks 6 on the front and back
Since reproduction can be performed by reading the back side of a, 6b, 7a, 7b, when different information such as a stereoscopic image and stereo is obtained at the same time and used as a storage medium for combining them, efficient control becomes possible. Moreover, the cost of the reproducing apparatus can be reduced. And the recording track 7a on the surface
Since the recording track 7b on the back side can be reproduced when the reproduction of is finished, it is suitable for the case of reproducing a continuous long time information, efficient control is possible, and the cost of the reproducing apparatus can be reduced. You can

In particular, in this embodiment, since the translucent films on both surfaces of the disk substrate 1 are made to have a transmittance of 30 to 60%, the reflection noise is reduced and the information is recorded from the recording tracks on the back sides of each other. Can be read and played.
This can be the embodiment of claim 6.

Further, in the disc manufacturing method of the present embodiment, a step of forming the disc substrate portion 1 in which the recording tracks 6a, 6b, 7a, 7b are simultaneously formed on both sides by two stampers C, D facing each other. , The recording track 6a,
Steps of forming the reflective layers 3a and 3b for forming the reflective layers 3a and 3b on both surfaces of the disk substrate portion 1 on which the disk substrate portions 6b, 7a and 7b are formed, and the reflective layers 3a and 3b on both surfaces of the disk substrate portion 1.
The protective layer 4a, 4b, 5a, 5b is formed on the surface of the disk, and the step of forming the protective layer 4a, 4b, 5a, 5b is performed.
The recording tracks 6a, 6b, 7a, 7b on the front and back sides can be formed at the same time, and this can be the embodiment of claim 7.

Therefore, the disc 10 for recording information
, Two recording stamps 6a, 6b, 7a, and
7b are simultaneously molded to form the recording tracks 6a, 6b, 7
Reflective layers 3 are formed on both sides of the disk substrate portion 1 on which a and 7b are formed.
a, 3b can be formed, and at the same time, recording tracks 6a,
6b, 7a, 7b can be formed. Therefore, since the reflection layers 3a and 3b can be formed on both sides of the disc substrate portion 1 on which the recording tracks 6a, 6b, 7a and 7b are formed at the same time, two reflection layers on one side of the disc substrate portion on which the recording tracks are formed are joined. Since a single disk 10 is not formed as a result, it is possible to easily form the disk 10 on which information is recorded on both sides.

Furthermore, in the disc reproducing apparatus of this embodiment, the recording tracks 6a, 6b, and 6b are formed on both sides of the disc substrate 1 by the two stampers C and D facing each other.
7a and 7b are simultaneously molded, and the recording tracks 6a and 6 are
In a disc 1 in which reflective layers 3a and 3b are formed on both sides of a disc substrate portion 1 on which b, 7a and 7b are formed, the reflective layers 3a and 3b on both sides of the disc substrate portion 1 are semitransparent films and The recorded information is read out simultaneously from the back surface, and the surface on one side can be reproduced by a ready-made reproducing device, which can be the embodiment of claim 8.

Therefore, the plurality of pickups 23R,
23L has the same speed, and the pickups 33U and 33D sequentially move in the radial direction of the disk 10 to reduce the mechanical error between the two and it is not necessary to uniformly control the speeds of a plurality of disks. , The device becomes cheap.

[0064]

As described above, according to the disc of claim 1, in the disc for recording information, the recording tracks are simultaneously formed on both surfaces of the disc substrate portion by the two stampers facing each other. A reflective layer is formed on both sides of the disk substrate part on which
At the same time, recording tracks can be formed on the front and back. Therefore,
At the same time, since the reflective layers can be formed on both sides of the disc substrate portion on which the recording tracks are formed, the two reflecting layers on one side of the disc substrate portion on which the recording tracks are formed are not joined to form one disc. It is possible to easily form a disc having information recorded on both sides. Therefore, MPE
It can be used as a storage medium for stereoscopic moving images such as the G system, can be easily reproduced, and can be easily manufactured for mass production.

According to the disc of claim 2, claim 1
Since the recording tracks on both sides of the disk substrate are spirals in opposite directions, front and back reproduction can be performed at the same time. Therefore, in addition to the effect of claim 1, since it is possible to reproduce the recording tracks on the front and back sides at the same time, it is efficient when used as a storage medium for obtaining different information such as a stereoscopic image and stereo at the same time and combining them. It can be controlled, and the cost of the reproducing apparatus can be reduced.

In the disk of claim 3, claim 1
Since the recording tracks on both sides of the disk substrate are spirals in the same direction, the front and back can be continuously reproduced. Therefore, in addition to the effect of the first aspect, since it is possible to reproduce the recording track on the back surface at the time when the reproduction of the recording track on the front surface is completed, it is suitable for reproducing a continuous long time information, The price for the software will be reduced, and efficient control will be possible.

According to the disc of claim 4, claim 1
The reflective layers on both sides of the disk substrate section are total reflection layers, and information can be read from and reproduced from recording tracks on the front sides of each other. Therefore, in addition to the effect of claim 1, although it is necessary to thicken the protective layer, since the recording tracks on the front and back can be reproduced at the same time, different information such as a stereoscopic image and stereo can be obtained at the same time, and the combined information can be stored. When used as a medium, efficient control is possible and the cost of the reproducing apparatus can be reduced. Further, since the recording track on the back side can be reproduced when the reproduction on the recording track on the front side is completed, it is suitable for reproducing a continuous long-time information, and the cost for the software of the disc is reduced, which is efficient. It can be controlled, and the cost of the reproducing apparatus can be reduced.

In the disk of claim 5, claim 1
The reflective layers on both sides of the disk substrate are semi-transparent films, and information can be read from and reproduced from recording tracks on the back sides of each other. Therefore, in addition to the effect of claim 1, there is no need to particularly thicken the protective layer, and at the same time, reproduction can be performed by reading the back surfaces of the front and back recording tracks.
When different information such as stereoscopic image and stereo is obtained at the same time and used as a storage medium for combining them, efficient control becomes possible. Moreover, the cost of the reproducing apparatus can be reduced. Then, when the reproduction of the recording track on the front surface is completed, the recording track on the rear surface can be reproduced,
This is suitable for reproducing information for a continuous long time, efficient control is possible, and the cost of the reproducing device can be reduced.

According to the disk of claim 6, claim 5
The translucent film on both sides of the disk substrate part of
Since it is set to 0%, in addition to the effect of claim 5, it is possible to reduce reflection noise and read and reproduce information from recording tracks on the back sides of each other.

According to a seventh aspect of the present invention, there is provided a method of forming a disk substrate portion in which recording tracks are simultaneously formed on both surfaces by two stampers facing each other, and both surfaces of the disk substrate portion on which the recording tracks are formed are formed. Since the storage medium is manufactured by the step of forming the reflective layer for forming the reflective layer and the step of forming the protective layer for forming the protective layer on the surfaces of the reflective layers on both surfaces of the disk substrate portion, the recording media on the front and back sides are simultaneously formed. Can be formed. Therefore, the recording tracks can be simultaneously formed on both sides of the disk substrate by the two stampers facing each other, and the reflective layers can be formed on both sides of the disk substrate on which the recording tracks are formed, and the recording tracks can be formed on the front and back sides at the same time. Therefore, the reflective layers can be formed on both sides of the disk substrate portion on which the recording tracks are formed at the same time.
Since one disc is not formed by joining the discs, it is possible to easily form discs having information recorded on both sides. It can also be used as a storage medium for stereoscopic moving images such as the MPEG system, is easy to reproduce, is suitable for mass production, and is easy to manufacture.

In the disk reproducing apparatus according to the present invention, recording tracks are simultaneously formed on both surfaces of the disk substrate portion by two stampers facing each other, and reflective layers are formed on both surfaces of the disk substrate portion on which the recording tracks are formed. In the recording medium having the above-mentioned structure, the reflective layers on both sides of the disc substrate are semitransparent films, and the recorded information is read simultaneously from the back surfaces of each other. Playback can also be performed. Therefore, it is not necessary to reduce the mechanical error between the plurality of pickups at the same speed or alternately use the pickups for reading, and to uniformly control the speeds of the plurality of disks. , The device becomes cheap. It can also be used as a storage medium for stereoscopic moving images such as the MPEG system, and can be used for each one side of the disk substrate portion.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a molding process of a recording medium according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the recording medium formed according to FIG. 1 with a center hole formed therein.

3 is a cross-sectional view of a reflective layer formed on the recording medium of FIG.

4 is a cross-sectional view of a protective layer formed on the recording medium of FIG.

FIG. 5 is a plan view of a spiral in which recording tracks on both sides are opposite to each other in a recording medium according to an embodiment of the present invention.

FIG. 6 is a plan view of a spiral in which recording tracks on both sides of a recording medium according to an embodiment of the present invention are in the same direction.

FIG. 7 is an overall block diagram of a reproducing apparatus for reproducing the recording tracks shown in FIG. 5 from a spiral storage medium whose directions are opposite to each other.

FIG. 8 is an overall block diagram of a reproducing apparatus for reproducing the recording tracks shown in FIG. 6 from a spiral storage medium in the same direction.

[Explanation of symbols]

 C, D stamper 1 disk substrate part 3a, 3b reflective layer 4a, 4b, 5a, 5b protective layer 6a, 6b, 7a, 7b recording track 10 disk 23R, 23L pickup 25R, 25L CDDA decoder 26R, 26L CD-ROM decoder 27R , 27L MPEG Decoder 33U, 33D Pickup 35 CDDA Decoder 36 CD-ROM Decoder 37 MPEG Decoder

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G11B 7/26 531 7215-5D

Claims (8)

[Claims] 1. In a disc for recording information, recording tracks are simultaneously formed on both sides of a disc substrate portion by two stampers facing each other, and reflective layers are formed on both sides of the disc substrate portion on which the recording tracks are formed. A storage medium characterized by the above. 2. The storage medium according to claim 1, wherein the recording tracks on both surfaces of the disk substrate are spirals in mutually opposite directions. 3. The storage medium according to claim 1, wherein the recording tracks on both surfaces of the disk substrate are spirals in the same direction. 4. The reflective layers on both sides of the disk substrate are
The storage medium according to claim 1, wherein the storage medium is a total reflection layer. 5. The reflective layers on both sides of the disk substrate are
The storage medium according to claim 1, wherein the storage medium is a semitransparent film. 6. The storage medium according to claim 5, wherein the translucent films on both surfaces of the disk substrate portion have a transmittance of 30 to 60%. 7. A method of manufacturing a disk for recording information, comprising: a step of molding a disk substrate portion for simultaneously molding recording tracks on both surfaces by two stampers facing each other; both sides of the disk substrate portion on which the recording tracks are formed. A method of manufacturing a storage medium, comprising: a reflective layer forming step of forming a reflective layer on the disk; and a protective layer forming step of forming a protective layer on the surfaces of the reflective layers on both surfaces of the disk substrate portion. 8. A recording medium in which recording tracks are simultaneously formed on both surfaces of a disk substrate portion by two stampers facing each other, and reflective layers are formed on both surfaces of the disk substrate portion on which the recording tracks are formed. A reproducing apparatus for a storage medium, characterized in that the reflective layers on both sides of the disk substrate are semitransparent films, and the recorded information can be read simultaneously from the back surfaces of each other.