JPH01150248A - Information recording medium and optical information recording medium - Google Patents

Abstract

PURPOSE:To enable the recording of music, etc., with a CD format and the reproduction thereof with a CD player by recording the lead-in information prescribed in the standards for compact disks (CD) on the inside circumferential side of a substrate and providing a recording layer which allows writing/reading on the outside circumferential side thereof. CONSTITUTION:Prebits are inscribed as the lead-in information on the doughnut part 2 on the outside of a central circular hole part 1 of the substrate and the recording layer 3 is provided on the outside circumferential part thereof. The music, etc., are recorded by the CD format signal on the layer 3 by using a laser beam of a high energy density. The recorded music, etc., can be reproduced by the CD player. Calling out of the recorded information in time unit is possible as well.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an information recording medium and a CD format signal that can be advantageously used for recording and reproducing compact disc (CD) format signals using a high energy density laser beam. The present invention relates to a method for recording information on the information recording medium.

[Technical Background of the Invention] In recent years, information recording media that use high energy density beams such as laser light have been developed and put into practical use. This information recording medium is called an optical disk and can be used as a video disk, an audio disk, a large-capacity still image file, and a large-capacity RL computer disk memory. Among these information recording media, compact discs (CDs) are widely used for audio reproduction of music and the like.

Compact discs (CDs) generally contain EFM (Eight to Four) signals such as CD format signals.
(teenModulation) It consists of a plastic disk-shaped transparent substrate in which holes (pits) containing digital audio signal information are formed in advance, and a reflective thin film and a protective film made of metal such as aluminum provided on this substrate. . Information from a CD is read by irradiating the optical disc with a laser beam, and CD format signals and the like are read by changes in reflectance depending on the presence or absence of pits.

Based on the CD standard, the CD length is 1.2 to 1.4 m.
By rotating and recording at a constant linear speed of /second, the pit width is 0.8 μm and the track pitch is 1.6 μm within the range of a signal surface inner diameter of 45 mm and a signal surface outer diameter t t of 6 mm.
It is required to have a maximum recording time of 74 minutes. Conventional audio CDs have pits formed on the substrate in advance (therefore, they do not have a recording layer) and are only for playback, and have the disadvantage that information cannot be recorded or edited. Direct Rea W
It is desired to develop a dAfterWrite (writable) type CD.

In addition, files such as documents, data, and still images can also be stored on CD-ROM (Read Only Memory).
y) or CD-1 (Interactive) is desired.

The basic structure of a normal DRAW type information recording medium is as follows:
A disc-shaped transparent substrate made of plastic, glass, etc.
It has a recording layer made of metal or semimetal such as Bi, Sn, In, Te, etc. provided thereon. Information is written on a recording medium by, for example, irradiating the recording medium with a laser beam, and the irradiated portion of the recording layer absorbs the light and locally increases in temperature, resulting in physical changes such as pit formation. Alternatively, information can be recorded by causing a chemical change such as a phase change to change its optical properties. Information is also read from the optical disk by irradiating the optical disk with a laser beam, and +ff information is generated by detecting reflected or transmitted light according to changes in the optical characteristics of the recording layer.

As described above, writing and reading information on an optical disc is usually performed by irradiating a laser beam onto a predetermined position on the disc surface.

On the other hand, since there is a strong desire to increase the amount of information recorded on optical discs, efforts are being made to increase the density of recording parts such as bits. As the density of the recording area increases, it becomes difficult to irradiate the laser beam correctly at a predetermined position.Recently, the laser beam is guided to accurately trace the irradiation target position (generally called tracking). ), tracking guide grooves (pregrooves) or tracking marks (servo bits) are often provided on the disk surface. The former method of providing tracking guide grooves on the disk in advance is called the continuous groove method, and the latter method of placing tracking marks here and there on the track is called the sample servo method.In particular, recently optical systems and signal processing systems have become easier. The sample servo method is attracting attention because of the fact that the focus signal does not reflect the guide groove.

In a DRAW type compact disc (optical disc) having the above-described configuration, access information to be retrieved is recorded in various forms because it is necessary to retrieve recorded information accurately and quickly. For example, in the case of an external memory for a computer or an electronic file memory, this access information is stored as a preformat signal in the head part of the sector structure, and in the case of an audio disc (compact disc), it is stored as a preformat signal on the inner circumference of the disc. Lead-in information is recorded in the program area, and subcode information is recorded in the program area. The former memory disk is for recording data and documents;
A recorded document can be recalled by a preformat signal as needed. Furthermore, the latter audio disc has information already recorded on it, and the music, etc. that one wants to listen to can also be called up using lead-in information and subcode information.

However, since it is not possible to record music or the like on the former memory disk, there is currently no optical disk that is easy to recall and on which music and the like can be recorded.

[Object of the Invention] The present invention provides an information recording medium and a recording method thereof that can record music, etc. in a CD format signal using a high energy density laser beam and easily reproduce it on a commercially available CD player. The purpose is to provide.

[Summary of the Invention] The present invention has a pre-pit section on which lead-in information specified in the compact disc standard is recorded on the inner donut-shaped surface of a disk-shaped substrate having a circular hole in the center.
and an information recording medium in which a writeable and/or readable recording layer is provided on the surface of the substrate on the outer circumferential side of the pre-pit portion; and; a donut-shaped surface on the inner circumferential side of the disk-shaped substrate having a circular hole in the center. information, which has a pre-pit section on which lead-in information specified in the compact disc standard is recorded, and a recording layer that can be written and/or read on the surface of the substrate on the outer peripheral side of the pre-pit section. Optical information recording comprising recording a CD format signal by irradiating light onto the recording layer on the outer peripheral side of the pre-pit portion while rotating the recording medium at a constant linear velocity of 1.2 to 2.8 m/sec. It's in the method.

[Effects of the Invention] As shown above, the information recording medium of the present invention is provided with a pre-pit section on the inner circumferential side in which lead-in information that allows the above-mentioned recording to be easily called up is recorded, and A recording layer is provided on the outer circumferential side, and is capable of recording music and the like in CD format signals using a high energy density laser beam. Music and the like can be recorded on the recording layer in the form of a CD format signal using a high energy density laser beam. Furthermore, these recorded information (music) can be played by commercially available compact disc players.

Therefore, in the information recording medium of the present invention, since the lead-in information is recorded on the inner circumference as described above, the recording time (15 minutes, 30 minutes, 45 minutes,
It is possible to provide discs with a fixed number of minutes (minutes, etc.), and to call up the recorded information in time units (minutes, seconds, etc.).
access).

[Detailed Description of the Invention] The information recording medium of the present invention can be manufactured, for example, by the following method.

The substrate used in the present invention can be arbitrarily selected from various materials used as substrates for conventional information recording media. For example, it can be manufactured by molding a plastic material such as polycarbonate resin or polyacrylic resin, or by laminating a resin layer having pregrooves on a flat substrate such as a plastic plate or glass plate. These methods are already generally known.

The information recording medium of the present invention has a pre-pit section on which lead-in information specified in the compact disc standard is recorded on the donut-shaped surface on the inner circumferential side of a disk-shaped substrate having a circular hole in the center; A recording layer is provided on the surface of the substrate on the outer peripheral side of the portion. That is, the information recording medium of the present invention is represented by two sheets as shown in FIG. It consists of a recording section 3.

This recording part is a recording layer part that can record music, etc. in CD format signals using a high energy density laser beam, and the above recording can be easily called up in the pre-pit part on the inner circumference side. Lead-in information can be recorded. For example, in the case of a compact disc, it is a disc-shaped board with an outer diameter of 120 mm and an inner diameter of about 15 mm, and the lead-in information above indicates that the inner diameter is 44 to 48 mm.
The information is recorded on a donut portion having an outer diameter of 48 to 52 mm, and a recording portion capable of recording music and the like in the form of a CD format signal is provided on the outer periphery of the donut portion.

The L-doin information consists of a track numbered 1 to n and an index numbered m, to m1 corresponding to the track, where n is an integer of 99 or less, and m, to It is common for each mI+ to have an integer index number of 99 or less. n is an integer less than or equal to 99 that is divisible by 10, and m, ~m
Preferably, the index numbers of each of n are all 60. In particular, it is preferable that n is 10.50.60 or 90.

In addition, in order to accurately and quickly call based on the lead-in information, the surface of the substrate on the outer peripheral side of the pre-pit section may have a tracking guide groove or a sample servo type wobble pit. preferable. After the recording layer is provided on the substrate, it is preferable that recording is performed within the groove or in full bloom in the case of a tracking guide groove, and on the blank surface in the case of an oblong pit. In particular, it is preferable to record on the grooves because good tracking performance can be obtained.

Music and the like can be recorded on the recording layer of the present invention in the form of a CD format signal using a high energy density laser beam. Furthermore, this information (music) can be played back by a commercially available compact disc player.

In the information recording medium of the present invention, lead-in information that allows the above-mentioned recording to be easily called up is recorded in the prepit portion on the inner circumferential side. This leave-in information is recorded on the inner side in the form of tracks and indexes as described above, so by setting these values to 0,
Like an audio tape, the recording time (15 minutes, 3
It is possible to provide discs with fixed lengths (0 minutes, 45 minutes, etc.). In addition, the lead-in information records the number and order of the song, the beginning and end of the song, and the time of the song, and when recording and playing back, the lead-in information on the inner side is first read. The recorded information can be recalled in time units (minutes, seconds).
be able to. An undercoat layer may be provided on the surface of the substrate on which the recording layer of the present invention is provided for the purpose of improving planarity, improving adhesive strength, and preventing deterioration of the recording layer.

Materials for the undercoat layer include, for example, polymeric substances such as polymethyl methacrylate, acrylic acid/methacrylic acid copolymer, nitrocellulose, polyethylene, polypropylene, and polycarbonate; organic substances such as silane coupling agents; and inorganic oxides. (Si02, Aj2203, etc.) and inorganic substances such as inorganic fluoride (MgF2).

In the case of glass substrates, alkali metal ions and alkaline earth metal ions released from the substrate can be harmful to the recording layer! In order to prevent No. 29, it is desirable to provide an undercoat layer made of a polymer having a hydrophilic group and/or a maleic anhydride group, such as a styrene/maleic anhydride copolymer.

The undercoat layer can be formed by, for example, dissolving or dispersing the above-mentioned substance in a suitable solvent, and then applying this coating solution to the substrate surface by a coating method such as spin cording, dip coating, or extrusion coating.

On the substrate of the present invention, pregrooves (tracking guide grooves) may be provided by molding on the substrate surface for the purpose of tracking grooves, or a pregroove layer may be provided by the method described below. Materials for layers such as pre-grooves include:
A mixture of at least one monomer (or oligomer) of acrylic acid monoester, diester, triester, and tetraester and a photopolymerization initiator can be used. The layer thickness of the layer such as the pregroove is generally in the range of 0.05 to 100 μm, preferably 0.05 to 100 μm.
It is in the range of 1 to 50 μm.

An intermediate coating layer may be formed on the surface of the substrate having prepits (or on the surface of the undercoat layer).

The intermediate coating layer can be formed on the substrate surface by a known coating method. Examples of known coating methods include a spin code method and a dip coat method.

Note that examples of the intermediate layer formed by the coating method include an adhesive layer, a heat insulating layer, a reflective layer, a sensitivity enhancement layer (gas generation layer), and the like.

When the intermediate coating layer is a heat insulating layer, for example, polymethyl methacrylate, acrylic acid/methacrylic acid copolymer,
Styrene/maleic anhydride copolymer, polyvinyl alcohol, N-methylol/acrylamide copolymer, styrene/sulfonic acid copolymer, styrene/vinyltoluene copolymer, chlorinated polyethylene, chlorosulfonated polyethylene, nitrocellulose, poly It can be formed using a coating solution in which polymeric substances such as vinyl chloride, polyester, polyimide, vinyl acetate/vinyl chloride copolymer, ethylene/vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, etc. are dissolved in a solvent. .

A coating solution using chlorinated polyethylene or nitrocellulose is preferred, and chlorinated polyethylene is particularly preferred.

The layer J (average layer thickness) of the intermediate coating layer is determined in consideration of the characteristics required of the intermediate layer. The layer thickness of the intermediate coating layer is usually in the range of 100 to 1000 angstroms.

A recording layer is provided on the substrate (via an undercoat layer, intermediate layer, and pregroove layer if desired).

Examples of materials used for the recording layer include Te, 2n, I
Metals such as n, Sn, Zr, An, Cu, Ge; Bi, A
Metalloids such as S and Sb; semiconductors such as Ge%Si; and alloys thereof, or combinations thereof. In addition, sulfides, oxides of these metals or metalloids,
Compounds such as borides, silicon compounds, carbides and nitrides; and mixtures of these compounds with metals can also be used in the recording layer.

The recording layer can be formed on the intermediate coating layer using the above recording material by a method such as vapor deposition, sputtering, or ion blasting. The recording layer may be a single layer or a multilayer, but its layer thickness is generally in the range of 100 to 5,500 angstroms in view of the optical density required for optical information recording.

The recording layer is formed on the substrate (or on the undercoat layer) using the above-mentioned recording layer material by a known method such as vapor deposition, sputtering, or ion blasting. However, if desired, an intermediate layer may be interposed between the undercoat layer and the recording layer. The recording layer may be a single layer or a multilayer.

Preferably, a protective layer is provided on the recording layer. The protective layer is preferably a laminate of a soft protective layer made of a soft resin material and a hard protective layer made of a hard resin material. This laminate is laminated on the recording layer with the soft protective layer side facing the recording layer side. Examples of the soft resin material include polycrethane, polyvinylidene chloride, ethylene/vinyl acetate copolymer, silicone rubber, styrene/butadiene rubber, polyvinylidene chloride, and polyacrylic acid ester. Typically these are solution applied, latex applied,
It is applied onto the recording layer by a method such as melt coating, and is subjected to treatments such as drying and heating if necessary to form a soft protective layer. The thickness of the soft protective layer is usually in the range of 100X to 5 μm, preferably in the range of 0.3 to 3 μm. Examples of hard resin materials include ultraviolet curing resins and thermosetting resins. Usually, these are applied onto the soft protective layer by a method such as solution coating, and if necessary UV irradiation is applied.
A hard protective layer is formed by processing such as heating. The thickness of the hard protective layer is usually in the range of 0.1 to 10 μm, preferably in the range of 1 to 3 μm.

The surface of the substrate opposite to the side on which the recording layer is provided is coated with inorganic substances such as silicon dioxide, tin oxide, and magnesium fluoride, or thermoplastic resins and photocurable resins to improve scratch resistance and moisture resistance. It may be provided by a thin film made of a polymer material such as mold resin, or by a method such as vacuum heating, sputtering, or coating.

A 1v-layout type information recording medium can be manufactured by joining two substrates having the above structure using an adhesive or the like. In an air sandwich type recording medium, at least one of the E disk-shaped substrates has the above-mentioned structure, and a ring-shaped outer spacer and an inner spacer are interposed therebetween, or one or both of the substrates is It can be manufactured by joining via protrusions provided on the.

Next, the optical information recording method of the present invention will be explained.

In the optical information recording method of the present invention, an information recording medium having a recording layer provided on the outer circumferential side of the pre-pit portion where the lead-in information is recorded is rotated at a constant linear speed of 1.2 to 2.8 m/sec. The CD format signal is recorded by irradiating the recording layer on the outer peripheral side of the pre-pit area with light. -Generally, recording light is 750 to 850 nm.
A semiconductor laser beam having an oscillation wavelength in the range of is used.

With the information recording medium of the present invention, recording can be performed with a laser power of 10 mW or less.

In addition, in order to perform the above-described recording on the recording layer,
It is preferable that the surface of the substrate on the outer peripheral side of the pre-pit portion has a tracking guide groove or a wobble pit of a sample servo type, etc., and tracking control is preferably performed by this. After the recording layer is provided on the substrate, recording is preferably performed on or between the grooves in the case of tracking guide grooves, or on the brane surface in the case of wobble pits. In particular, it is preferable to record on the grooves because good tracking performance can be obtained.

Information can be reproduced by rotating the recording medium at the same constant linear velocity as described above, irradiating semiconductor laser light from the substrate side, and detecting the reflected light. In the present invention, since the recording layer has a high reflectance of 60% or more on a plain plane, it can be read satisfactorily using an IFi CD player.

Next, examples of the present invention will be described. However, each of these does not limit the present invention.

[Example] A pre-pit is carved as lead-in information in a donut-shaped portion ranging from an inner diameter of 46 mm to an outer diameter of 50 mm, and a pre-pit is carved to a depth of 0.07 μm in a range of an inner diameter of 45 mm to an outer diameter of 116 mm.
A disc-shaped polycarbonate substrate (outer diameter:
120 mm, inner diameter: 15 mm, thickness: 1.2 mm), a recording layer was provided by co-evaporation at a ratio of In:GeS:Au=66:22:12 (weight ratio). The lead-in information has 90 tracks and 60 indexes for each index.

Next, sound information was recorded using the following time program.

1) Bird (Lark) cry 00:00-05:12
2) Sound of waves 06: 00-09:
523) Car exhaust sound 10:00-15:
324) People talking 16:00-45:
215) Reference signal (2kHz sine wave) 46:00~
50:00 Information was reproduced from the optical disc on which the above recording had been performed using a CD player (Technics 5L-XP7, Matsushita Electric Industrial ■).

When accessing track 5, index 59,
One second later, the sound of waves was played.

Also, when track 15, index 59 was accessed, human speech was played back one second later.

As shown in this embodiment, by using the information recording medium of the present invention, it is possible to access arbitrarily recorded information in seconds (in seconds).

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an information recording medium of the present invention. 1: Circular hole part, 2: Pre-pit part, 3: Recording section

Claims (1)

[Claims] 1. A disk-shaped substrate having a circular hole in the center has a prepit section on the inner circumferential side of the donut-shaped surface on which lead-in information specified in the compact disc standard is recorded, and the substrate surface on the outer circumferential side of the pre-pit section. An information recording medium provided with a recording layer that can be written to and/or read from. 2. The lead-in information consists of tracks numbered 1 to n and indexes numbered m_1 to m_n corresponding to the tracks, where n is an integer of 99 or less, and each of m_1 to m_n is 99. The information recording medium according to claim 1, having the following integer index numbers. 3. The above n is an integer of 99 or less that is divisible by 10,
3. The information recording medium according to claim 2, wherein the index numbers of m_1 to m_n are all 60. 4. Claim 1, characterized in that a tracking guide groove is provided on the surface of the substrate on the outer peripheral side of the pre-pit portion.
Information recording medium described in section. 5. 2. The information recording medium according to claim 1, further comprising wobble pits for tracking on the surface of the substrate on the outer peripheral side of the pre-pit portion. 6. A disk-shaped substrate having a circular hole in the center has a prepit section on the inner circumferential side of the donut-shaped surface on which lead-in information specified in the compact disc standard is recorded, and the substrate surface on the outer circumferential side of the pre-pit section. While rotating an information recording medium provided with a recording layer that can be written to and/or read from at a constant linear speed of 1.2 to 2.8 m/sec, the recording layer on the outer peripheral side of the pre-pit portion is An optical information recording method comprising recording a CD format signal by irradiating light. 7. The lead-in information consists of tracks numbered 1 to n and indexes numbered m_1 to m_n corresponding to the tracks, where n is an integer of 99 or less, and each of m_1 to m_n is 99. 7. The optical information recording method according to claim 6, wherein the following integer index numbers are used. 8. The above n is an integer of 99 or less that is divisible by 10,
8. The optical information recording method according to claim 7, wherein the index numbers of m_1 to m_n are all 60. 9. 7. The optical information recording method according to claim 6, wherein the CD format signal is recorded on or between the tracking guide grooves by irradiating the recording layer with light. 10. 7. The optical information recording method according to claim 6, wherein the recording layer is irradiated with light to record a CD format signal in a plain portion accompanying wobble pits.