JPS63121143A - Optical card and its manufacture - Google Patents

Abstract

PURPOSE:To inexpensively obtain a direct read after write (DRAW) type optical card having superior and stable recording sensitivity with simplified constitution, by making an optical recording layer into a pattern in a stripe shape. CONSTITUTION:An organic system thin film 9 is formed on a transparent substrate 1 as the optical recording layer. Next, by projecting a laser beam whose wavelength is absorbed by the organic system thin film 9 on a part equivalent to a track groove part 2 by stopping it, the optical recording part 3 is formed in the pattern of stripe shape by a heat mode method which diffuses and peels the organic system substance at the part of the track groove 2 where is the irradiated part of the organic system thin film 9. Next, by bonding a card base material 5 on the optical recording part 3 and the track groove part 2 through a bonding layer 4, the optical card can be obtained. In such way, it is possible to easily manufacture the DRAW type optical card capable of performing tracking, automatic focusing, and recording and reproduction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical card 3 and a method of manufacturing the same, and more particularly to a cart-shaped information recording carrier for optically recording and reproducing information and a method of manufacturing the same.

[Prior Art] In recent years, society has become increasingly information-oriented, and information recording carriers and information recording devices such as optical discs, optical cards, and optical tapes that record or reproduce optical information have become a means of efficiently handling a wide variety of information. Many playback devices have been proposed. On the information recording carrier, the binarized information is recorded as changes in reflectance and bits (
There are some methods that can be detected by converting changes in the intensity of reflected light due to changes in surface shape, such as the presence or absence of holes.

As a record carrier that relies on changes in optical reflectance, a so-called heat mode recording material has been proposed, which records by irradiating the two layers with a spot-like energy beam such as a laser beam to change the state of a part of the recording layer. has been done. These recording materials are so-called DRAW [
Direct read After write (direct
read, afterwrite)] medium capable of high-density recording, and additional writing is also possible.

In optical information recording and reproducing devices, there is a method in which grooves are formed in advance at regular intervals on the card surface for track servo for writing and reading. In this method, the grooves serve as a readout guide, which improves the accuracy of laser beam track control and enables faster access than conventional methods using substrates without grooves.

To form track grooves on a substrate, if the substrate is made of thermoplastic resin, a method of thermally transferring a stamper mold using a method such as injection molding or hot press molding at a temperature above the melting point, or a method of thermally transferring a stamper mold onto the substrate using a method such as injection molding or hot press molding at a temperature above the melting point, Apply a curable resin composition and apply a stamper.
A method of photo-transferring a stamper mold is conventionally known by bringing the molds into close contact with each other and curing the photocurable resin composition by irradiating the mold with ultraviolet rays or the like.

Next, an explanation will be given using an optical card as an example of an optical information recording carrier. FIG. 2 is a schematic cross-sectional view of a conventional optical cart. In FIG. 2, 6 is a transparent resin base material, 7 is a track portion, 8 is an optical recording layer, 4 is an adhesive layer, and 5 is a card base material.

In Fig. 2, information is recorded and reproduced using the transparent resin base material 6.
In conventional optical cards in which writing and reading are performed optically through the track section 7, in the case of the thermal transfer method described above, the track section 7 is integrated with the transparent resin base material 6 and is made of the same material. On the other hand, in the case of the optical transfer method, the track portion 7 is not made of the same material as the transparent resin base material 6, but is in a state of being bonded. In any case, a track groove corresponding to a light guide groove is formed in advance, and tracking can be performed using the phase difference of the laser beam by utilizing minute irregularities. Further, the optical cart is easily manufactured by forming the optical recording layer 8 on the track portion 7 and bonding the opaque cart base material 5 with the adhesive layer 4 interposed therebetween.

[Problems to be Solved by the Invention] As described above, since an optical card has a structure in which an optical recording layer is formed on a transparent resin base material having an uneven shape, first, an uneven shape is formed on a transparent resin base layer. must be formed,
In that case, the yield of stamper mold transfer and the cost of the stamper mold depend on the price of the optical card, so there is a problem that the manufacturing cost of the optical card increases. Furthermore, since the recording sensitivity of the optical recording layer depends on the film thickness, uniform film formation is required, but since the optical recording layer is formed on top of the uneven structure, it is difficult to reproducibly form a uniform film thickness. It has become difficult.

The present invention was made for the purpose of solving the above problems, and by patterning the optical recording layer into stripes, it is possible to create a DRAW type light beam with a simpler structure than the conventional one and with good and constant recording sensitivity. The purpose is to provide cards at low prices.

[Means for Solving the Problems] That is, the present invention provides an optical recording section patterned in stripes on a transparent substrate, and a card base material is laminated on the optical recording section via an adhesive layer. An optical card characterized in that an organic thin film is formed on a transparent substrate, and a portion of the organic thin film corresponding to the line width of a guide groove is peeled off using a laser beam heat mote method to form a striped pattern. This method of manufacturing an optical cart is characterized in that after an optical recording section is formed, a card base material is laminated onto the optical recording section via an adhesive layer.

The present invention will be explained in detail below.

FIG. 1 is a schematic cross-sectional view of an optical card according to the present invention. In FIG. 1, 1 is a transparent substrate, 2 is a track groove portion, 3 is an optical recording portion, 4 is an adhesive layer, and 5 is a card base material.

3 in FIG. 1, the optical card of the present invention is provided with a track groove portion 2 serving as a guide groove and an optical recording portion 3 made of an organic Q film patterned in a stripe shape on a transparent substrate l. A cart base material 5 is laminated on the recording section 3 via an adhesive N4.

The width of the track groove portion 2 is usually preferably 2 to 44 ta.

Further, the optical recording section 3 is formed in a stripe shape, and the line width thereof is usually preferably about 3 to 10 pm.

The track groove portion 2 is formed to such an extent that there is almost no organic thin film constituting the optical recording portion, or there is only a very thin organic film.

Next, a method for manufacturing an optical card according to the present invention will be explained.

FIGS. 3(a) and 3(b) are schematic process diagrams showing a method for forming the optical recording portion 3 patterned in the form of a strip of an optical card according to the present invention. First, in FIG. 3(a), an organic thin film 9 is formed as an optical recording layer on a transparent substrate l.

Next, in FIG. 3(b), the organic thin WJ 9 obtained in FIG. 3(a) is focused into a beam with a laser beam having a wavelength that is absorbed by the organic thin film 9 to form a beam corresponding to the track groove portion 2. By irradiating the area, the organic substance in the track groove portion 2, which is the irradiated area of the organic thin film 9, is scattered and peeled off. Such a method is called a heat mode method.

For example, by narrowing the beam diameter of the laser beam to approximately the width of the track groove, which is equivalent to the line width of the guide groove, it is possible to easily leave the optical recording section 3 on the transparent substrate and form the track groove 2. . Furthermore, by linearly scanning the laser beam, the optical recording section 3 can be formed into a striped pattern. Alternatively, the track grooves 2 can be formed by irradiating a high-power laser beam such as an excimer laser through an optical mask having an optical density pattern that allows the track grooves 2 to pass through.

In this case, all the track grooves can be formed by repeatedly applying laser beam pulses in steps.

As a result, there is almost no organic thin film in the track groove 2, or the film thickness is more than two orders of magnitude smaller than the initial film thickness, and the organic thin film is extremely thin.
Thin < May remain 0 Next, an optical card can be obtained by bonding the card base material 5 onto the optical recording section 3 and the track groove section 2 via the adhesive layer 4.

As the transparent substrate l, it is preferable to use a material with few inconveniences in optical recording/reproduction, and any material having high transmittance to the light used may be used, such as acrylic resin, polyester resin, polycarbonate resin, Vinyl resin, polysulfone resin, polyimide resin, polyacetal resin, polyolefin resin, polyamide resin, cellulose conductor, etc. can be used.

The optical recording unit 3 has a wavelength near the wavelength 1 of the light to be used.
In the case of 0 to 900 nm, it is preferable that there is a large difference between the reflectance of pits, etc., which are recorded areas, and that of unrecorded areas, and in order to record, there must be absorption in the above wavelength range. is necessary.

Further, it is preferable that the energy required to cause a change in reflectance by irradiation with an energy beam is small. Furthermore, the recording section (
It is preferable that the reflectance of pits, etc.) and undistributed Rfi& is hard to change.

Further, the organic F1 film 9 whose optical properties can be changed by an energy beam can be continuously coated using a solution or a dispersion system, which is preferable for mass production.

For example, anthraquinone derivatives (especially those having an indathrene skeleton), dioxazine compounds and their derivatives, triphuedithiazine compounds, phenanthrene derivatives, cyanine compounds, merocyanine compounds, biryllium compounds, xanthine compounds, triphenylmethane compounds, croconium pigments, azo pigments, crocones, azines, indigoids, polymethine pigments, azulenes,
Squarium derivatives, sulfur dyes and metal dithiolate complexes may be mentioned.

Such organic thin films such as dyes can be formed by known coating methods, such as dip coating, spray coating, spinner coating, bar code coating, blade coating, roll coating, and curtain coating. The thickness of the thin film is approximately 500 to 2000, preferably around 1000. In particular, from the viewpoint of recording sensitivity, it is desirable that the film be thin, but from the viewpoint of reproduction S/N ratio, it is desirable that it be thicker, and the optimum film thickness differs depending on the type of dye.

When applying a solvent solution of a dye, since the viscosity of the solvent solution is low, if it is applied onto a track portion that has a conventional uneven shape, a pool of liquid tends to occur in either the track groove portion or the optical recording portion. However, in the present invention, it is easy to form a uniform film because the coating is applied on the smooth surface of the transparent substrate l.

As the cart base material 5, any material that can be used as a normal card base material can be used, and specifically, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, polymethyl methacrylate. Acrylic polymers, polystyrene, polyvinyl butyral, acetyl cellulose, styrene-butadiene copolymers, polyethylene, polypropylene, polycarbonates, epoxies, acrylonitrile-butadiene-styrene copolymers, etc. are used. Depending on the case, metal sheets such as iron, stainless steel, aluminum, tin, copper, and zinc, synthetic paper,
Paper etc. can also be used. Furthermore, an A-layer body made of the materials mentioned above can also be used. These card base materials 5 may be pretreated to improve adhesion, such as corona discharge treatment, plasma treatment, and primer treatment, if necessary.

Examples of the adhesive layer 4 include hot melt type ethylene-vinyl acetate copolymer and its modified resin, ethylene-ethyl acrylate copolymer, vinyl acetate-acrylate copolymer, etc., and these are made of an organic thin film. Preferred for adhesion of optical recording layers.

In addition, heat-curing, photo-curing, photo-curing, and 8 combination adhesives may attack the optical recording layer, so they cannot be applied directly, so they must be applied partially or after being covered with a protective film. I can do it. These adhesives may be known ones and are not particularly limited.

The optical cart may be provided with a magnetic recording layer, an IC memory, an engraved image, a photograph, a character, a mark, an ink, an embossed character called an ink print, etc. on the front or back side of the optical card, if necessary.

Furthermore, a hard coat can be applied to the surface of the transparent substrate l to prevent scratches.

[Function] The optical card according to the present invention is formed by forming an organic thin film on a transparent substrate, and peeling off the portion corresponding to &l@ of the guide groove of the organic thin film using a laser beam heat mode method to form a striped pattern. After forming an optical recording section, a card base material is bonded to the optical recording section via an adhesive layer, and an optical recording section and a track groove patterned in stripes are provided on a transparent substrate. For example, if a dye-based thin film is used as an organic thin film, the reflectance of the track groove for incident light from the transparent substrate side is higher than that of the track groove. The reflectance of the recording portion is approximately 5% and j5%, respectively, and since the reflectance of the track groove portion is low, it is possible to sufficiently detect the tracking signal. Furthermore, since the reflectance of the optical recording section is three times that of the track groove, it is possible to fully utilize autofocus.

[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A diacetone alcohol solution (concentration: 3% by weight) of a dye represented by the following formula (I) was placed on a transparent methacrylic resin plate (manufactured by Nitto Jushi Kogyo Co., Ltd.) with a thickness of 0.4H as a transparent substrate.
A recording layer having a thickness of about 100 OA was formed by coating with a spinner.

CI) Next, a laser beam with a wavelength of 830 nm and a laser power of 10 layers W is irradiated onto the recording layer with a beam diameter of 3.5 pm to form an optical recording part with a line width of 10 pm and a depth of 0.1 g. A striped pattern with track grooves of &1 width and 3 ends was formed.

On the other hand, as a card base material, a thermoplastic adhesive (EVA
FLEX (manufactured by DuPont Mitsui Polychemical Co., Ltd.), and superimpose it so that it is in contact with the optical recording layer 1. The surface temperature is 12.
They were bonded together by pressure bonding using a heated roll at 0°C. After that, the surface of the transparent substrate 1 was coated with an epoxy acrylate hard coating agent (
An optical card was manufactured by coating the film with Azoka Ultra Set (manufactured by Asahi Denka Kogyo Co., Ltd.) and curing it with ultraviolet light.

'This optical card has a wavelength of 8:1 On, laser power of 0.
．． When reproduction was performed under the conditions of 4 watts, a beam diameter of 4.5 mm, a recording pit diameter of 3 mm, and a frequency of 80 KHz, a C/N ratio of 48 dB was obtained.

[Effects of the Invention] As explained above, according to the present invention, track grooves are not formed by an expensive stubber-type transfer consisting of uneven shapes as in the past, but an optical recording layer is formed using an organic thin film laser. A striped pattern can be formed using the optical heat mode method, and a DRAW type optical cart that can perform tracking, autofocus, recording and reproduction can be easily manufactured.

In addition, the track grooves are formed by peeling off the uniformly formed organic thin film using the heat mote method using laser light.
An optical cart with constant recording sensitivity can be obtained, and defects such as non-uniformity in film thickness that occur in the respective steps of forming track grooves and forming an optical recording layer, which are observed in conventional methods, can be suppressed.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an example of an optical card according to the present invention, FIG. 2 is a schematic cross-sectional view of a conventional optical cart, and FIG.
Figures (a) and (b) are schematic process diagrams showing a method for forming an optical recording section of an optical card according to the present invention. l...Transparent substrate 2...Track groove part 3
... Optical recording section 4 ... Adhesive layer 5 ... Card base material 6 ... Transparent resin base material 7 ... Track section 8 ... Optical recording layer 9 ... Organic thin film

Claims (2)

[Claims] (1) An optical card characterized in that an optical recording section patterned in stripes is provided on a transparent substrate, and a card base material is laminated on the optical recording section via an adhesive layer. (2) An organic thin film was formed on a transparent substrate, and a portion of the organic thin film corresponding to the line width of the guide groove was peeled off using a laser beam heat mode method to form an optical recording section patterned into stripes. A method for manufacturing an optical card, which comprises: thereafter laminating a card base material onto the optical recording portion via an adhesive layer.