JPH07311982A - Optical recording medium and its manufacturing device and method - Google Patents

Abstract

PURPOSE:To obtain an inexpensive and high-quality optical recording medium and its manufacturing device and method where no dust is generated when writing medium information. CONSTITUTION:A recording layer 2 containing coloring matter, a reflection layer 3, and a protection layer 4 are successively laminated on a transparent resin substrate 1. In the title optical recording medium, medium information is recorded at the innermost periphery part of the optical recording medium as an optically changing matter 5 of the recording layer 2 whose data can be read by the reflection of light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium, and more particularly to a single-plate type high-rewritable write-once optical recording medium having a recording layer of a dye capable of recording a large amount of information, and a manufacturing method and manufacturing apparatus thereof. .

[0002]

2. Description of the Related Art A single plate type recordable optical recording medium is known in which a metal reflection layer is provided on a recording layer made of a dye, and a protective layer is further provided thereon (Optical Data Storage 1989).
Technical Digest Series Vol.1 45 (1989), JP-A-2
-132656, JP-A-2-168446, etc.). This type of optical recording medium can be used interchangeably with CD-ROM players and CD-I players, which are commercially available compact disc (hereinafter abbreviated as CD) players.

By the way, in an optical recording medium, information about the origin of the medium, such as the name of the manufacturing company of the medium, the name of the manufacturing factory, the manufacturing line, the manufacturing date, etc. (generally referred to as medium information in this specification), is generally provided. As recorded, these media information are usually readable by the human eye. However, recently, in order to make the management of the medium efficient, an optical recording medium has been proposed in which the medium information can be read by a writer or a reader. In such an optical recording medium, after forming a reflective layer, the reflective layer is removed by, for example, laser light and medium information is written as a bar code or the like, and then a protective film for protecting the reflective layer is formed. What you have done is known. When the medium information is read by a writer or reader, it is usually read by utilizing reflection or transmission of light.

However, in the case of manufacturing the above optical recording medium, dust is generated when the reflective layer is removed, and the dust adheres on the remaining reflective layer, degrading the quality of the medium. there were. According to the investigations by the present inventors, the reflective layer is generally made of a very thin and soft metal film, so that the reflective layer is easily scratched when dust is removed, and the dust deposited on the reflective layer Was difficult to remove. Then, when a protective layer is formed on the reflective layer while the removal of dust is incomplete, coating defects due to dust are likely to occur, and the generated coating defects not only deteriorate the appearance of the medium, Cracks occur in the protective layer near the area where dust adheres,
Alternatively, it was found that peeling of the film is easily caused.

On the other hand, in JP-A-5-258352, a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated on a transparent resin substrate so that medium information can be read by a writer or a reader. In manufacturing a certain optical recording medium, after the first protective layer is formed on the reflective layer, laser light is radiated from above the first protective layer to remove the reflective layer to obtain medium information. A technique has been proposed in which writing is performed and a second protective layer is formed thereon. It is said that this technique can eliminate the above-mentioned problems caused by the generation of dust.

[0006]

However, the use of the technique described in the above publication has the following problems. (1) A high-power laser marker such as a YAG laser marker with a second harmonic oscillation unit is required for writing medium information, which makes the equipment expensive and raises the cost. (2) The dust generated when writing the medium information must be completely removed, and the charge removal blow is required. (3) Since it is necessary to provide a protective layer again on the portion where the medium information is written, the number of steps is increased and a step can be formed at the portion where the medium information is written. Streak-like unevenness in film thickness occurs.

The present invention solves the above-mentioned problems of the prior art, and provides an inexpensive and high-quality optical recording medium in which dust is not generated when writing medium information, and a manufacturing apparatus and manufacturing method thereof. The purpose is to

[0008]

In order to achieve the above object, according to the present invention, there is provided an optical recording medium in which a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated on a transparent resin substrate. There is provided an optical recording medium characterized in that the medium information is recorded on the innermost peripheral portion of the optical recording medium as an optically changed substance of a recording layer which can be read by reflection of light.

According to the present invention, there is provided an apparatus used for manufacturing the above optical recording medium, which is at least:
Rotate media information and a turntable that rotates at an equal angular velocity while clamping an optical recording medium that is formed by sequentially stacking a recording layer containing a dye, a reflective layer, and a protective layer on a transparent resin substrate and generating a rotation origin pulse. It has a data pulse generator that outputs a data pulse in synchronization with the origin pulse, a pickup that mounts a laser that emits light according to the data pulse and a lens that condenses the laser light so that it can move in the radial direction of rotation of the optical recording medium. An apparatus for manufacturing an optical recording medium is provided.

Further, according to the present invention, there is provided a method for producing the above optical recording medium, which comprises a transparent resin substrate, and a recording layer containing a dye, a reflective layer and a protective layer, which are sequentially laminated. Is rotated at an equal angular velocity, and the optical recording medium is irradiated with laser light synchronized with the rotation to scan in the radial direction,
There is provided a method for manufacturing an optical recording medium, which is characterized in that the optically changed substance of the recording layer is formed in an arc shape.

The present invention will be described in detail below. As shown in FIG. 1, the optical recording medium of the present invention basically comprises a transparent resin substrate 1, a recording layer 2 containing a dye, a reflective layer 3 and a protective layer 4, which are sequentially laminated, and The optical recording medium is characterized in that the medium information is recorded on the innermost peripheral portion of the optical recording medium as an optically variable substance 5 of the recording layer 2 which can be read by reflection of light. Here, the optically changed substance of the recording layer is a substance that forms a pit portion during normal recording, and is altered or deformed by heating with laser light, and has optical characteristics (transmittance, reflectance at the wavelength of the reproduction laser light). Etc.) are different from those before recording. The medium information to be written is, for example, the name of the medium manufacturer,
Information on the origin of the medium, such as the name of the manufacturing plant, the name of the manufacturing line, the date of manufacture, the manufacturing lot, etc. It is preferable that the medium information be replaced with numbers and recorded as a bar code as shown in FIG. Further, it is preferable that the medium information is provided in an arc shape. Further, it is preferable that the medium information is recorded as an optically changed substance 5 of the recording layer 2 by laser light.
In the optical recording medium of the present invention, since the medium information is recorded as the optically changed substance 5 of the recording layer 2, dust is not generated, reliability is improved, and recording can be performed using a low output laser. There is an advantage that the manufacturing cost is low.

The medium information written as the optically changed substance 5 of the recording layer 2 can be read by a writer or a reader. As a reading method, light may be irradiated and the difference in the amount of reflected light or transmitted light may be detected.

Next, an apparatus and method for manufacturing the optical recording medium of the present invention will be described. FIG. 3 is an apparatus for manufacturing an optical recording medium according to the present invention, and more specifically, an innermost circumference of a medium in which a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated on a transparent resin substrate. FIG. 3 is a diagram schematically showing an apparatus for recording medium information as an optically changed substance of a recording layer that can be read by reflection of light in a section. In the figure, 11 is a turntable, 12 is a data pulse generator, 13 is a pickup, and 14 is an optical recording medium for recording medium information. The turntable 11 is configured such that the optical recording medium 14 is attached so that the transparent substrate faces downward and is rotated at a constant angular velocity (CAV). A rotary encoder (not shown) is attached to the turntable 11, and one rotation origin pulse (see FIG. 4) is generated by one rotation. The data pulse generator 12 is
In addition to inputting the medium information, a rotary origin pulse is input from the rotary encoder, and the medium information is output as a data pulse in synchronization with the rotary origin pulse. In this case, the medium information recorded on the optical recording medium 14 as the character information is read by an optical means, and the read information is used as the medium information.
Is preferably provided to form the data pulse. The pickup 13 is equipped with a laser that emits light in response to the data pulse and a lens that collects the laser light emitted from the laser, and is movable in the radial direction of rotation of the optical recording medium.

In order to form an optically changed substance of the recording layer as medium information, the optical recording medium 14 is attached to the turntable 11 so that the transparent substrate faces downward, and the turntable 1 is turned on.
Rotate 1 at a constant angular velocity. The rotary encoder generates one rotation origin pulse each time the turntable 11 makes one rotation, and supplies it to the data pulse generator 12.
On the other hand, image reading means such as a scanner (1 in FIG.
By 5), the medium information recorded as character information (image information) on the inner circumference (φ15 to φ33) of the disc is supplied to the data pulse generation unit 12, and the data pulse generation unit 12 converts the medium information into data pulses. The data pulse generator 12 then
The data pulse is output to the pickup 13 in synchronization with the rotation origin pulse. In the pickup 13, the laser emits light in response to the data pulse, the laser light is focused on the recording layer of the optical recording medium 14 through the lens, and the laser-irradiated portion is in an optically changed state. Then, the pickup is gradually moved in the outer peripheral direction to record all medium information. In this case, it is preferable that the rotation speed of the optical recording medium (rotation speed of the turntable 11) is 100 to 1000 rpm, the radial moving speed of the pickup is 0.1 to 1 mm / s, and the laser power is 5 to 20 mW. It is preferable that the pickup 13 is set so that its moving speed in the radial direction becomes slower toward the outer peripheral side of the optical recording medium. By doing so, the laser power shortage when the linear velocity becomes high can be compensated.

Next, required characteristics of each part of the optical recording medium according to the present invention will be described. First, the transparent resin substrate used in the present invention is preferably one that transmits light for recording and reading signals. The light transmittance of the resin substrate is preferably 85% or more, and one having small optical anisotropy is desirable. Examples of such a resin substrate include a substrate using a thermoplastic resin such as an acrylic resin, a polycarbonate resin, a polyamide resin, a vinyl chloride resin, or a polyolefin resin. Of these, a molded resin substrate of an acrylic resin, a polycarbonate resin, or a polyolefin resin is preferable from the viewpoint of mechanical strength of the substrate, easiness of giving a groove or a reproduction-only signal, and economical efficiency, and a polycarbonate resin is particularly preferable. Substrates are most preferred. The resin substrate is usually formed by injection molding or casting. The shape of these substrates may be plate-like, film-like, circular or card-like. Grooves for controlling the recording position may be formed on the surfaces of these substrates, or pits for partially reproducing only information may be formed. Such grooves and pits are preferably added when the resin substrate is produced by injection molding or casting.

The optical recording medium of the present invention has a basic structure in which a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated on a transparent resin substrate, but the recording layer containing the dye. The dyes used for are polymethine dyes,
Examples thereof include phthalocyanine dyes, naphthalocyanine dyes, naphthoquinone dyes, azulene dyes, and dithiol metal complex dyes, which have absorption in the oscillation wavelength range of a semiconductor laser. These dyes may be substituted with various kinds of substituents in order to control solubility in a solvent, recording characteristics and the like. Further, these dyes may be used alone or in combination of two or more. Among these dyes, phthalocyanine dyes and naphthalocyanine dyes are preferable in consideration of dye durability.

In the present invention, the recording layer containing the above-mentioned dye can be usually formed by a coating method such as spin coating, spraying or dipping. When the dye is formed by a coating method, it is preferable that the dye is dissolved and applied in a solvent that does not damage the resin substrate, that is, a solvent that does not substantially dissolve the resin for the substrate. Generally, the film thickness of the recording layer is preferably 500 to 2000Å. In the present invention, after forming the recording layer, the outermost recording layer may be removed with a solvent in order to improve the adhesion of the protective layer.

When the recording layer containing a dye is formed, a resin such as nitrocellulose, ethyl cellulose, acrylic resin, polystyrene resin, urethane resin, a leveling agent, an antifoaming agent, etc. may be used in addition to the above-mentioned dye. They can also be used in combination as long as the effects of the present invention are not impaired.

In the present invention, the reflective layer provided on the recording layer is usually preferably a metal thin film. Considering the compatibility with ordinary CD players, a material having a reflectance of 60% or more on the groove of the medium is preferable. Preferred metals for forming the reflective layer include aluminum, gold,
Examples thereof include silver, copper, platinum, nickel, and alloys containing these metals as one component. Such a metal reflective layer is vapor deposited,
The film can be formed by a method such as spatter. The thickness of these reflective layers is usually preferably about 500 to 2000 Å. As a matter of course, it is preferable to form the reflective layer beyond the groove portion.

In the present invention, a protective layer is provided on the reflective layer, and a resin is usually used to form this protective layer. From the viewpoint of the protective effect, a thermosetting resin, particularly a thermosetting resin, is used. An ultraviolet curable resin is preferable in terms of productivity. The thickness of the protective layer is preferably about 1 to 15 μm, and the protective layer is preferably formed over the outer edges of the recording layer and the reflective layer (to the outer side thereof).

Next, examples of the present invention will be described. Example 1 3 parts by weight of a mixture of a phthalocyanine dye represented by the following formula (1) and a phthalocyanine dye represented by the following formula (2) in a molar ratio of 100: 20: 100 parts by weight of 2-ethoxyethanol To be a coating solution. A recording layer having a thickness of about 1300Å was formed on a polycarbonate substrate by the spin coating method using the above coating solution. Next, a gold reflection layer of about 1000 liters was provided by a sputtering method, and a UV-curable resin was spin-coated on the gold reflection layer and was irradiated with ultraviolet rays to be cured to form a protective layer, thereby preparing an optical recording medium.

[0022]

[Chemical 1]

[0023]

[Chemical 2]

Next, the above optical recording medium was attached to a turntable and rotated at a constant angular speed of 300 rpm to give a diameter of 39.
A laser beam is focused on the recording layer surface on the circumference of mm by a pickup, and a rotation origin pulse is used as a trigger to generate a bar code converted data pulse.
Recording was performed by emitting a laser having a wavelength of m at 6.0 mW in response to a data pulse. While recording, move the pickup 0.2 to the position of 42.8 mm diameter on the medium.
The recording medium was moved at a speed of mm / s to form an arc-shaped bar code as shown in FIG. 5 as medium information to obtain an optical recording medium according to the present invention.

[0025]

According to the present invention, because of the above-mentioned constitution, the following remarkable effects can be obtained. (1) Since the medium information is recorded by the optical change of the recording layer, dust is not generated and a high quality optical recording medium can be provided. (2) Since the medium information can be recorded with a low output laser, an optical recording medium can be provided at low cost. (3) Since the medium information is recorded by emitting laser light in synchronization with the rotation origin pulse, for example, when the medium information is recorded by a bar code, the bar code is not distorted and the medium information can be accurately read.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing the basic structure of an optical recording medium of the present invention.

FIG. 2 is a diagram showing a state in which medium information is recorded as a barcode.

FIG. 3 is a diagram schematically showing an apparatus for manufacturing an optical recording medium according to the present invention.

FIG. 4 is a diagram showing a relationship between a rotation origin pulse and a data pulse.

FIG. 5 is a diagram showing a bar code representing medium information formed in the embodiment of the present invention.

[Explanation of symbols]

 1 Transparent Resin Substrate 2 Recording Layer 3 Reflective Layer 4 Protective Layer 5 Optical Change (Media Information) 11 Turntable 12 Data Pulse Generator 13 Pickup 14 Optical Recording Medium

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G11B 7/26 501 5017215-5D

Claims (3)

[Claims] 1. An optical recording medium in which a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated on a transparent resin substrate, and the medium information reflects light at the innermost peripheral portion of the optical recording medium. An optical recording medium, which is recorded as an optically changed substance of a recording layer that can be read by. 2. An apparatus used for manufacturing the optical recording medium according to claim 1, wherein at least a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated on a transparent resin substrate. A turntable that clamps an optical recording medium and rotates at a constant angular velocity while generating a rotation origin pulse, a data pulse generator that outputs medium information as a data pulse in synchronization with the rotation origin pulse, and emits light in response to the data pulse. An apparatus for manufacturing an optical recording medium, comprising a pickup on which a laser and a lens for condensing a laser beam are mounted so as to be movable in a rotation radius direction of the optical recording medium. 3. A method for producing an optical recording medium according to claim 1, wherein an optical recording medium comprising a transparent resin substrate, on which a recording layer containing a dye, a reflective layer and a protective layer are sequentially laminated, at a constant angular velocity. The method for producing an optical recording medium is characterized in that the optical recording medium is rotated in a radial direction, and the optical recording medium is scanned in the radial direction while irradiating the optical recording medium with a laser beam in synchronization with the rotation, thereby forming an optical change in the recording layer in an arc shape.