JPS6196538A - Optical card - Google Patents

Abstract

PURPOSE:To realize a pigment optical card having high contrast and a high S/N by providing a recessed part for voids on the substrate, and forming a void having >=0.01mm size between an optical recording layer and a protective layer. CONSTITUTION:A recessed part for forming a void 5 is provided on the record ing part forming surface of a substrate 2 consisting of an acrylic resin, etc. A recording layer 3 consisting of a pigment composition and a protective layer 4 consisting of a resin are laminated on the substrate 2. The voids 5 having >=0.01mm size are formed between the recording layer 3 and the protective layer 4. When the voids 5 having >=0.01mm size are formed between the optical recording layer and the protective layer 4, the contrast can be increased by 2 times as compared with the conventional one, and an optical card having a high S/N can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. BACKGROUND OF THE INVENTION Technical Field The present invention relates to an optical card, and particularly to an optical card that performs heat mode optical recording.

Prior art and its problems In general, magnetic recording methods are widely known for recording and reproducing information. Examples include magnetic recording media such as magnetic tape, magnetic disks, and magnetic recording cards. One example of this usage is a magnetic card used as a cash card or the like.

As is well known, the magnetic recording/reproducing method allows information to be easily recorded, erased, and rerecorded. Therefore, if a magnetic card using this method is misused or placed in a magnetic field such as a magnet, the information recorded will change, resulting in low information reliability.
Magnetic cards have the disadvantage that they can only record low-density information due to magnetic field limitations, and furthermore, they can only record a very small amount of information due to limitations based on the size of the card.

Therefore, it is impossible to take a complicated signal form to prevent misuse due to the above-mentioned limitations on the magnetic card.

Recording and reproducing methods based on optical principles have recently been proposed to improve these drawbacks. Optical cards are examples of devices based on this optical recording and reproducing method.

This optical card has a wide range of applications, and is expected to be put to practical use in a wide variety of applications, including bank cash cards, credit cards, ID cards, driver's licenses, commuter passes, public phone cards, and gasoline purchasing cards. ing.

By the way, there is a heat mode optical recording medium that can be applied to an optical card.

This heat mode optical recording medium is an optical recording medium that uses recording light as heat. One example is a heat mode optical recording medium that uses recording light such as a laser to melt or remove a part of the medium to form a pit. There is a pit-forming type in which writing is performed by forming small holes, information is recorded using the pits, and reading is performed by detecting the pits with a readout light.

Until now, most of these pit-forming type media, especially those using a semiconductor laser as a light source that can make the device smaller, have a recording layer made of a material mainly composed of Te.

However, in recent years, because Te-based materials are harmful and there is a need to increase sensitivity and lower manufacturing costs, organic materials mainly containing various dyes have been used instead of Te-based materials. Proposals and reports on media using recording layers of this type are increasing.

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

However, when the recording layer and the protective layer are brought into close contact with each other in this way, the reflectance of the dye-based recording layer decreases.

It has the disadvantage of low contrast and S/N ratio.

(2) Object of the Invention An object of the present invention is to provide an optical card having a dye-based recording layer with high contrast and S/N ratio.

■Disclosure of invention Such objects are achieved by the invention described below.

That is, one aspect of the present invention is an optical recording section having a substrate and a recording layer made of a dye or a dye composition.

An optical card having a protective film, wherein a recess is formed in the substrate, and the recess forms a gap of 0.01 mm or more between the optical recording section and the protective film. It's a card.

■Specific structure of the invention Hereinafter, the specific configuration of the present invention will be explained in detail.

FIG. 1 shows an embodiment of the invention.

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

The substrate 2 is usually made of a resin material, and may be made of acrylic resin, polycarbonate, nylon, polyolefin, or the like.

However, considering printability, lamination, moisture resistance, strength, etc.
Polyvinyl chloride-based polymers are preferred. The polyvinyl chloride-based polymer may be a vinyl chloride homopolymer or a vinyl chloride copolymer such as vinyl chloride-vinyl acetate or vinyl chloride-maleic acid.

The thickness of the substrate 2 is approximately 0 mm, where 1=1.

A recessed portion is formed on the surface of the substrate 2 on which the optical recording portion is formed.

The recess is for forming a gap 5, which will be described later, and is set to be 0.01 mm or more in accordance with the gap length.

In this case, the depth of the recess is preferably equal to or less than the thickness of the substrate from the viewpoint of strength.

Further, the recess may be provided over almost the entire area of the substrate, or may be provided partially. When provided partially,
That portion may be used as a recording track.

Furthermore, the recesses may be in the form of continuous grooves or dots, or may be provided over the entire area of the substrate, if necessary.

Note that the recesses are formed by pressure molding.

It may be formed during injection molding.

A recording layer 3 is provided on the substrate z.

The recording layer may consist of a single dye or a single dye composition.

The dye to be used may be appropriately determined from among those that effectively absorb the writing light and reading light depending on the wavelengths of the writing light and reading light. In this case, the light source for these light sources is:
Since it is preferable to use a semiconductor laser because the device can be made smaller, the dyes are cyanine-based, phthalocyanine-based,
Anthraquinone type, azo type, triphenylmethane type, biryllium or thiapyrylium salt type, etc. are preferred.

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

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

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

The recording layer is made of ketone or ester.

A spinner coat or the like may be applied using an ether-based, aromatic-based, halogenated alkyl-based, or alcohol-based solvent, or vapor deposition may be performed.

Such a recording layer may have a thickness of 0.01 to 10 ILm, and preferably has a thickness of 0.05 to 14 m.

Note that a groove for tracking control can be provided, but in that case, the thickness of the recording track portion in the recording layer is
0.2gm or less, more preferably 0.05-0.15p
It is preferable to set it to m.

Such an optical recording layer may be used as an optical recording section by itself, or it may be formed as an optical recording section by providing an upper layer or a base layer on the recording layer.

As the upper layer or underlayer, a semi-transparent film (half-mirror single layer), a reflective layer, etc. may be provided above and below the recording layer.

Such an optical recording section is provided in a striped, rectangular, etc. shape on the entire surface or a part of the substrate depending on the use of the card.

Note that the recording layer only needs to be formed within the recessed portion, and may or may not be formed on the substrate convex portion other than the recessed portion.

A protective film 4 is provided on the optical recording section.

The protective film 4 is usually formed by fusing or adhering film bodies.

Various resins are suitable as the material for the protective film 4, but the above-mentioned polyvinyl chloride polymer is particularly suitable in terms of moisture absorption and scratch resistance.

The thickness thereof is approximately 0.1 to 1.0 mm.

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

Note that the protective film 4 may have various coating layers for preventing cracking.

The substrate also has an optical recording section and a storage area on both sides.
, and these may be provided only on one side.

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

Such a protective film sheet is fused or adhered to the convex portion of the substrate 2.

Due to such fixation of the protective film sheet, a gap 5 is formed between the protective film 4 and the recording section.

Such a void is 0.01+*m or more.

This is because if it is less than 0°01 mm, the contrast improvement effect will not be effective.

Note that, if necessary, recesses can also be formed in the protective film sheet to correspond to the recesses of the substrate.

Note that it is preferable that the entire surface of the recording layer be sealed from the outside by the protective film 4.

This eliminates deterioration of the recording layer.

■Specific Effects of the Invention According to the present invention, there are 0 and 0 between the optical recording section and the protective film.
Since a gap of 1 m or more is formed, contrast and S/N ratio are improved.

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

Experimental Example 85 x 54 x 0.3 mm vinyl chloride resin sheet with a thickness of 0.06 μm, 1.1'.

3.3.3', 3'-hexamethyl-4°4', 5.
5″-dipenzo-2,2′-indotricarbocyanine perchloride) (double, fc part) and NIR-PA
100'6 (manufactured by Mitsui Toatsu Chemical Co., Ltd., bisphenyldithiol-Ni complex) (1 part by weight) was provided.

On top of this, a sheet made of vinyl chloride resin and having a thickness of 0.3 mm was heat-sealed.

Note that recesses were formed in the substrate with a depth of 0.1 mm, a width of 3 mm, and an interval of 3 mm.

When recording and reproducing were performed using a semiconductor laser, the contrast was twice as high as when no recesses were formed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the optical card of the present invention. Explanation of symbols l・・・・・・・Optical recording card, 2......Substrate, 3... Recording layer, 4......protective member, 5・・・・・・Gap Applicant TDC Co., Ltd. Times Tokyo Magnetic Printing Co., Ltd. FIG.1

Claims (1)

[Claims] (1) In an optical card having a substrate, an optical recording section having a recording layer made of a dye or a dye composition, and a protective film, a recess is formed in the substrate, and the recess allows the optical recording section and the protective film to be connected to each other. An optical card characterized in that a gap of 0.01 mm or more is formed between the card and the card.