JPH0639188B2 - Light card - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical card, and more particularly to an optical card for performing heat mode optical recording.

Prior Art and Problems Thereof In general, a magnetic recording method is widely known for recording and reproducing information. For example, magnetic tape, magnetic disk,
A magnetic recording medium such as a magnetic card may be used. One example of this use is a magnetic card used as a cash card or the like.

As is well known, the magnetic recording / reproducing system can easily record, erase and re-record information. Therefore, a magnetic card using this method has a low reliability of information such as a change in recorded information when it is abused or placed in a magnetic field such as a magnet. In addition, the magnetic card can only record low density information due to the restrictions of the magnetic head,
Further, there is a drawback that only a very small amount of information can be recorded due to the limitation based on the size of the card. Therefore, the means of taking a complicated signal form for preventing abuse is impossible due to the above restrictions on the magnetic card.

In order to improve these drawbacks, a recording and reproducing system based on an optical principle has recently been proposed. Examples of the optical recording and reproducing system include an optical disk and an optical card.

Among them, optical cards have a wide range of applications, and are expected to be put into practical use in a wide variety of fields including bank cash cards, credit cards, identification cards, driver's licenses, commuter passes, public telephone cards, and gasoline purchase cards. There is.

By the way, as an optical recording medium applicable to the optical card, there is a heat mode medium.

This heat mode optical recording medium is an optical recording medium that uses recording light as heat, and as one example thereof, a part of the medium is melted and removed by recording light such as a laser and is called a pit. There is a pit formation type in which a small hole is formed for writing, information is recorded by this pit, and the pit is detected by reading light to perform reading.

Most of the pit formation type media, especially those having a semiconductor laser as a light source, which can miniaturize the device, have a recording layer mainly made of a material containing Te.

However, in recent years, Te-based materials are harmful, need to have higher sensitivity, and manufacturing costs need to be reduced. The number of proposals and reports on media using the above recording layer is increasing.

By the way, in an optical card, it is necessary to form a protective film on the recording layer in order to prevent damage to the recording layer. Since the protective film is laminated with the base material, the recording layer and the protective film are in close contact with each other.

However, if the recording layer and the protective layer are in close contact with each other as described above, there is a drawback that the contrast and the S / N ratio are small.

II OBJECT OF THE INVENTION It is an object of the present invention to provide an optical card with high contrast and S / N ratio.

III DISCLOSURE OF THE INVENTION Such an object is achieved by the present invention described below.

That is, the first invention is an optical card having a resin substrate, a recording layer containing a dye, and a protective layer, wherein the recording layer and the resin substrate are simultaneously deformed by irradiation of recording light. Is an optical card characterized by.

Further, a second invention is an optical card having a resin substrate, a recording layer containing a dye, and a protective film, wherein the recording layer and the resin substrate are simultaneously deformed by irradiation of recording light. Moreover, the optical card is characterized in that a space is provided between the recording layer and the protective film.

IV Specific Structure of the Invention Hereinafter, the specific structure of the present invention will be described in detail. An embodiment of the present invention is shown in FIGS. 1, 2 and 3.

As shown in FIGS. 1, 2, and 3, the optical card of the present invention has a substrate 2.

The substrate 2 is usually made of a thermoplastic resin material, and may be any of acrylic resin, polycarbonate, polyvinyl chloride, nylon, polyolefin, polyester and the like.

Considering the need to configure the recording layer and the substrate to be simultaneously deformed by irradiation with recording light, and the printability, stackability, moisture resistance, strength, etc., a polyvinyl chloride polymer is preferable. . Polyvinyl chloride polymers include, in addition to vinyl chloride homopolymers, vinyl chloride-
It may be a vinyl chloride copolymer such as vinyl acetate or vinyl chloride-maleic acid.

The thickness of the substrate 2 is about 0.1 to 1.0 mm.

In addition, a groove for tracking may be formed in such a substrate 2.

The recording layer 3 is provided on the substrate 2.

The recording layer 3 is configured to be deformed at the same time as the above-mentioned substrate 2 by irradiation of recording light.

As the recording layer, a dye alone or a dye composition can be used.

The dye to be used may be appropriately determined from those that effectively absorb the wavelengths of the writing light and the reading light. In this case, as these light sources, since it is preferable to use a semiconductor laser from the viewpoint that the device can be downsized, the dye is cyanine-based, phthalocyanine-based,
Anthraquinone-based, azo-based, triphenylmethane-based, pyrylium or thiapyrylium salt-based and the like, with high reflectivity are preferable.

When the dye composition is used as the recording layer, a self-oxidizing resin such as nitrocellulose or a thermoplastic resin such as polystyrene or nylon can be contained. Further, in order to prevent oxidative deterioration of the dye, a quencher may be contained. Furthermore, other additives may be contained.

In such a case, a mixture of an indolenine type cyanine dye and a bisphenyldithiol type quencher is particularly preferable.

It is also preferable to use these as an ionic bond between the cation of the dye and the anion of the quencher.

In this case, the recording layer may be applied by using a solvent such as a ketone type, an ester type, an ether type, an aromatic type, an alkyl halide type or an alcohol type.

Furthermore, the recording layer may have a metal layer provided by vapor deposition or the like. As the metal layer, Ag, Au, B
There are single metals or alloys such as i, In, Sn, Al, Ga, Ni and Cr.

At this time, a laminated body of a metal layer and a dye-based layer is formed.

As described above, the recording layer preferably exhibits high reflectivity with respect to the recording system or reproduction light, and in general, it preferably exhibits reflectance of 25% or more.

Such a recording layer may have a thickness of 0.01 to 10 μm, and particularly preferably a thickness of 0.05 to 0.1 μm.

Such a recording layer may be an optical recording unit by itself.
Alternatively, an optical recording part can be formed by forming an upper layer or a base layer on the recording layer.

Such an optical recording unit is provided on the entire surface or a part of the substrate in a stripe shape, a rectangular shape, or the like, depending on the application of the card.

As shown in FIGS. 1, 2, and 3, a protective film 4 is provided on the optical recording portion.

Although the protective film 4 can be formed by coating, it is usually formed by fusing or adhering a film body.

As the material of the protective film 4, various resins are suitable, but the above-mentioned polyvinyl chloride-based polymers are particularly preferred from the viewpoint of hygroscopicity, resistance to scratches and the like.

The thickness is about 0.1 to 1.0 mm.

This is because if it is less than 0.1 mm, recording and reproduction are hindered by the influence of dust and dust, and if it exceeds 1.0 mm, it becomes unsuitable for practical use.

In addition, the protective film 4 may have a coating layer for preventing various types of scratches.

Further, the substrate may have an optical recording layer and a protective layer on both sides thereof, and these may be provided on only one side.

In the latter case, a protective layer may be formed on the back surface of the substrate.

Such a protective film 4 is usually in close contact with the optical recording layer 3 as shown in FIG.

Further, as shown in FIG. 2 and FIG.
A void 5 may be formed between the optical recording layer 3 and the optical recording layer 3 in order to improve the contrast and the S / N ratio.

In the latter case, the S / N ratio and the contrast are further improved.

Such voids 5 are formed over the entire surface of the optical recording portion as shown in FIG. 2, or as shown in FIG.
By forming the convex portion 41 on the protective film 4, it can be partially formed. As a method of partially forming the void, other than the above, it is also possible to provide a concave portion or a convex portion on the substrate, interpose a spacer, or the like. The portion provided with this void serves as a normal recording track.

The length of the void 5 is determined by the height of the convex portion 41, the thickness of the spacer when a spacer is interposed, and the like.

The void length is usually 0.01 mm or more.
At this time, the contrast becomes extremely large.

The tip of the convex portion 41 of the protective film 4 is adhered or fused to the recording layer 3 or the substrate 2. When the spacer is interposed, the spacer may be formed of various resins such as polyester and polyvinyl chloride, and may be adhered or fused to the recording layer 3 or the substrate 2 and the protective film 4.

A pit 21 is formed in the optical card 1 of the present invention. The pits 21 are formed by melting and deforming a part of the substrate together with the recording layer by recording light such as laser light.

The diameter of the pit is usually about 0.8 to 10 μm, and the depth of the pit is usually about 0.05 to 1 μm.

The size and number of the pits may be determined in consideration of the required information storage capacity and various technical problems.

V. Specific Effect of the Invention According to the present invention, since the recording layer and the substrate are simultaneously deformed by irradiation of recording light, an optical card with improved contrast and S / N ratio can be obtained.

The present inventors conducted various experiments to confirm the effect of the present invention. An example is shown below.

Experimental example 1,1 ', 3,3,3', 3'-hexamethyl-4,4 ', 5,5'- with a thickness of 0.06 μm on a vinyl chloride resin sheet of 85 × 54 × 0.3 mm. Dibenzo-2,2 '
A recording layer made of indotricarbocyanine perchlorate (2 parts by weight) and IRA-PA-1006 [bisphenyldithiol Ni complex manufactured by Mitsui Toatsu Chemicals, Inc.] (1 part by weight) was provided.

A vinyl chloride resin 0.3 mm-thick sheet was heat-fused on this.

The substrate and the recording layer were configured to be simultaneously deformed by irradiation with recording light (semiconductor laser). The pit formed by the deformation has a depth of 0.3 μm and a width of 5 μm.
The interval was 0 μm.

When recording / reproducing was performed using a semiconductor laser, the contrast was remarkably improved as compared with the case where a Si-based undercoat was formed on the substrate to prevent simultaneous deformation of the substrate and the recording layer.

Further, when the protective film was provided with a void of 0.1 mm as shown in FIG. 3, the contrast was further improved.

[Brief description of drawings]

1, 2, and 3 are sectional views of the optical card of the present invention. Explanation of symbols 1 ... Optical card 2 ... Substrate, 21 ... Pit 3 ... Recording layer 4 ... Protective film, 41 ... Convex portion 5 ... Void

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroshi Hosaka 1-5-1 Taito, Taito-ku, Tokyo Within Tokyo Magnetic Printing Co., Ltd. (72) Inventor Ryohei Mimura 1-5-1 Taito, Taito-ku, Tokyo Within Tokyo Magnetic Printing Co., Ltd.

Claims (2)

[Claims] 1. An optical card having a resin substrate, a recording layer containing a dye, and a protective film, wherein the recording layer and the resin substrate are simultaneously deformed by irradiation of recording light. Optical card to do. 2. An optical card having a resin substrate, a recording layer containing a dye, and a protective film, wherein the recording layer and the resin substrate are simultaneously deformed by irradiation of recording light, and the recording layer is also formed. An optical card characterized in that a space is provided between the protective film and the protective film.