JPS61132381A - Optical card - Google Patents

Abstract

PURPOSE:To enhance contrast and S/N of a recording layer comprising a coloring matter, by a method wherein bubbles are generated at a recording part by irradiation with recording light, thereby deforming an optical recording part. CONSTITUTION:The optical card 1 comprises a base 2, on which a recording layer 31 is provided. The optical recording part 3 may be constituted solely of the recording layer 31, but is preferable to constitute the optical recording part 3 of the recording layer 31 and a reflective layer 35 provided on the upper or lower side of the layer 31. By this, contrast is enhanced. The optical recording part is deformed when a bubble is generated in the recording layer 3 by irradiation with recording light. The bubble is ordinarily generated in the form of being convex in the direction opposite to the base. Accordingly, where the optical recording part comprises the reflective layer 35 which is deformed in response to the deformation of the layer 31, the layer 35 is preferable formed of a material which can be deformed in response to the deformation of the recording layer 31. A protective covering layer 4, which is a coated scratch- preventive layer, may be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION 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 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 re-recorded. Therefore, if a magnetic card using this method is misused or placed in a magnetic field caused by a magnet, the information recorded on the card will change, resulting in low information reliability. Further, magnetic carts have the disadvantage that they can only record information at a low density due to limitations of the magnetic head, 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 adopt a 1i crude signal format to prevent misuse due to the limitation of 5 or more magnetic carts.

Recording and reproducing methods based on optical principles have recently been proposed to improve these drawbacks. Examples of devices based on this optical recording and reproducing method include optical discs and optical cards.

Among these, optical cards have a wide range of applications, and are 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 telephone cards, and gasoline purchasing cards. There is.

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.

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 Q layer made of a material mainly composed of Te.

However, in recent years, due to the toxicity of Te-based materials, the need for higher sensitivity, and the need to lower manufacturing costs, organic materials, mainly containing various dyes, have been replaced with Te-based materials. An increasing number of proposals and reports are being made regarding media that use recording units.

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

However, when pits are formed by bringing the recording area and the protective layer into close contact in this way, the reflectance of the dye-based recording area decreases.
It has the disadvantage of low contrast and S/N ratio.

II. OBJECTS OF THE INVENTION An object of the invention is to provide an optical card having a dye-based recording portion with high contrast and S/N ratio.

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

That is, the present invention provides an optical card having a substrate, an optical recording section having a recording section, and a protective film, which is configured so that air bubbles are generated in the recording section by irradiation with recording light, thereby deforming the optical recording section. It is an optical card featuring the following.

■Specific structure of the invention Hereinafter, a 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 of the present invention has a substrate 2. As shown in FIG.

The substrate 2 is usually made of a thermoplastic resin material, and may be made of acrylic resin, polycarbonate, polyvinyl chloride, polyvinyl chloride, nylon, polyolefin, etc. However, the material is subject to printability, lamination, moisture resistance, and strength. Considering that,
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 O11 to 1.0 mm.

A recording section 31 is provided on the substrate 2 .

The recording portion is preferably made of a dye alone or a dye composition.

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

Further, when the dye composition is used as the recording part, it may 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 be contained.

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 the cation of the dye and the 7-ion of the quencher.

Although any of these can generate bubbles depending on the recording conditions, it is preferable that the recording portion contains a self-oxidizing resin to make bubble generation more efficient.

The recording layer is made of ketone, ester, ether,
Coating may be performed using aromatic, halogenated alkyl, alcohol, or other solvents. Alternatively, vapor deposition may be performed.

Such a recording portion may have a thickness of 0.01 to 104 m, and preferably has a thickness of 0.05 to 0.1 m.

Such an optical recording section 31 may be used as the optical recording section 3 by itself. Or the upper echelons of the recording department.

Alternatively, an underlayer can be provided to form an optical recording section.

As the upper layer or base layer, it is preferable to provide a reflective layer 35 above or below the recording section 31. This improves the contrast.

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.

Further, as shown in FIG. 1, the optical recording section is configured to be deformed by generating bubbles in the recording section 3 by irradiation with recording light. Formed in a convex shape.

Therefore, when providing a reflective layer 35 that deforms as the recording section 31 deforms in the optical recording section, the reflective layer should be made of a material that can deform as the recording section deforms. For example, A, Au, Examples include Bi, In, Sn, Ga, Ni, and Cr.

The thickness of this reflective layer is usually 100 to 100 lo.

Approximately O people.

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

Although the protection s4 can be formed by coating, it is usually formed by fusing or adhering a film body.

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 the thickness 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 be unsuitable for practical use.

Note that the protective film 4 may have various coating layers for preventing flaking. Also, the substrate may have an optical recording section and a protective layer on both sides, and these may be provided only on one side. You can leave it there.

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

Such protection! 115i4 is normally in close contact with the optical recording section 3, as shown in FIG.

In addition, protection It! J4 is bonded or fused to the recording section 3 or the substrate 2.

V. Specific Effects of the Invention According to the present invention, an optical card with improved contrast and S/N ratio can be obtained. 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 PVC resin sheet with 0.06jL11 thickness 1.1', 3°3.3', 3
'-hexamethyl-4,4'.

5.5'-dibenzo-2,2'-indotricarbocyanine verchlorate (2 parts by weight) and IRA-FA Ichiban 1006 [bisphenyldithiol N1fi form manufactured by Mitsui Toatsu Chemical Co., Ltd.] (1 part by weight) and 1 part by weight of nitrocellulose (R5-80), and a 300 mm thick reflective layer of Au were provided.

A 0.3 mm thick sheet of vinyl chloride resin was heat-sealed onto this.

Comparing the structure in which air bubbles are generated in the recording area to deform the recording area as in Section E, and the recording area in which the recording area does not contain nitrocellulose and are recorded in such a way that air bubbles are not formed, the contrast is lower. It has improved significantly.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an optical card according to the present invention. Explanation of symbols 1... Optical card, 2... Substrate, 3... Optical recording section, 31... Recording section, 35...
・Reflection layer, 4...protection! f film, Applicant TDC Co., Ltd. IFjl Tokyo Magnetic Printing Co., Ltd.・εij::i l-”

Claims (2)

[Claims] (1) An optical card having a substrate, an optical recording section having a recording section, and a protective film, characterized in that the optical recording section is deformed by generating bubbles in the recording section by irradiation with recording light. A light card. (2) The optical card according to claim 1, wherein the recording section has a recording section and a reflective layer, and bubbles are generated at the interface between the recording section and the reflective layer.