JPS6194248A - Optical card - Google Patents

Abstract

PURPOSE:To attain good contrast and a high S/N with an optical card by forming a >=0.01mm gap between an optical recording part and a protection film. CONSTITUTION:An optical card 1 contains a substrate 2 which usually uses the acrylic resin, polycarbonate, nylon, polyolefin, etc. The thickness of the substrate 2 is set at about 0.1-1.0mm, and a recording layer 3 is provided on the substrate 2. While a protection film 4 is formed on an optical recording part by melt-sticking or adhering a film matter of polymer of a polyvinyl chloride group with about 0.1-1.0mm thickness. Furthermore a gap 5 is formed between the optical recording part and the film 4 with >=0.01mm length. In other words, a desired recess is formed to the film 4, and the film 4 is melt- stuck or adhered to the layer 3 or the substrate 2 through a projected part excepting said recess of the film 4. The layer 3 is shielded entirely from an outside system with the film 4 to prevent the deterioration of the layer 3. In such a way, both the contrast and the S/N are improved.

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 rG tape, magnetic disks, and magnetic recording cards.
One example of this usage is a magnetic recording 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 magnetic recording cards using this method are misused or placed in the magnetic field of a magnet, the information recorded on them will change, resulting in low information reliability. Due to the card's limitations, it is only possible to record low-density information, and due to the size of the card, only an extremely small amount of information can be recorded.Therefore, in order to prevent misuse, The use of complex signal formats is also not possible due to limitations on one or more magnetic recording cards.

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.

The range of applications for this optical card is wide, and it is expected that it will 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, gasoline purchasing cards, etc. 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. There is a pit-forming type in which a small hole is formed to perform fortune telling, information is recorded using the pit, and the pit is detected with a readout light and read out.

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, Te-based materials have been found to be harmful, and there is a need for higher sensitivity.

Due to the need to lower manufacturing costs, Te
Instead, there are an increasing number of proposals and reports on media using recording layers made of organic materials containing various dyes.

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 2I retention film is laminated with the base material, the recording layer and the M retention film are in close contact with each other. However, when the recording layer and the protective layer are formed in this way, the dye-based recording layer has the disadvantage that the reflectance is lowered and the contrast and S/N ratio are low.

[IObject 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, the present invention provides an optical card having a substrate, an optical recording section having a recording layer made of one dye or a dye composition, and a protective film. This is an optical card characterized by having a.

■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 present invention.

As shown in the first factor, the optical card l of the present invention has a substrate 2.

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 l rigidity, laminability, #wet strength, etc.
Poly-enhanced vinyl-based polymers are preferred. The polyvinyl chloride-based polymer may include homopolybutylene chloride, vinyl chloride copolymers such as vinyl chloride-vinyl acetate, and vinyl chloride-maleic acid.

The thickness of the substrate 2 is approximately 0.1" 1.0 mm. A recording layer 3 is provided on the substrate 2.

The recording layer consists of one dye alone or one dye composition.

The pigments used are 1. Depending on the wavelengths of the sinking light and readout light, the light source may be appropriately determined from among those that can effectively absorb them. 1 Pigments are cyanine and phthalocyanine.

Anthraquinone type, azo type, triphenylmethane type, pyrylium or thiapyrylium salt type, etc. are preferred.

Further, when a single dye composition is used as a recording layer, a self-oxidizing resin such as nitrocellulose, or a thermoplastic resin such as polystyrene or nylon can be contained. In addition, a quencher may be included in order to prevent the dye from deteriorating due to fermentation. 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 the cation of the dye and the 7-ion of the quencher.

The J9 MI of the recording layer may be coated with a spinner coat using a ketone-based, ester-based, ether-based, aromatic-based, halogenated furkyl-based, or alcohol-based melt.

Such a recording layer may have a thickness of 0.001 to 1 Ou, and preferably has a thickness of 0.05 to 0.1 μm.

Note that the substrate may be provided with grooves for traffking control, but in this case, the thickness of the recording track portion in the recording layer is 0.21 Lm or less, more preferably 0.05-0.
．． The thickness is preferably 15 μm.

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

Upper or lower #! As a layer, semi-transparent Il is placed above and below the recording layer.
! (half-mirror single layer), a reflective layer, etc. may be provided.

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.

There is a protection l on the optical recording section! 4 is provided.

Although the adhesive layer 51124 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 lI 24, especially in terms of moisture absorption and scratch resistance.

The aforementioned polyvinyl chloride-based polymers are preferred.

The thickness thereof is approximately 0.1-1.0*■.

This is because if the value is less than 0.1, recording and reproduction will be inhibited by the shadow π of dust and dirt, and if it exceeds 1, Os-, it will become unsuitable for practical use.

Note that the protection v4 may have a coating layer for various types of IEs to prevent fireworks.

Further, the substrate 2 may have an optical recording section and a protective layer on both sides thereof, 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.

Under such a premise, a gap 5 is formed between the optical recording section and the protective film.

Forming the voids 5 by forming recesses in the protective film sheet 4 is suitable for manufacturing. This is because the recesses can be easily formed by pressure molding, injection molding, etc. during molding of the protective film sheet.

Such a gap should be 0.01 m or more.

This is because if it is less than 0.01×1, the contrast improvement effect will not be effective.

Note that, from the viewpoint of strength, it is preferable that the void size is 1/2 or less of the retention XIg.

Further, the void may be provided over the entire surface of the optical recording section.
It may be provided partially. When provided partially, that portion may be used as a normal recording track.

That is, it is sufficient to form the desired four portions on the 1[C film sheet and fuse or adhere to the recording layer or substrate at the convex portions other than the concave portions.

Further, the recesses to be bonded to the recording layer may be continuous or dotted. However, it is preferable that the entire surface of the recording layer is sealed from the outside by the protective film 4. Deterioration of the recording layer is eliminated.

■Specific Effects of the Invention According to the present invention, between the optical recording section and the protective film, 0,0
Since voids larger than is■ are 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.

Example 8 1.1', 3°3.3', 3' on a 5x54x0.3+*- vinyl chloride resin sheet with a thickness of 0.06 pm
-hexamethyl-4,4'.

5. Record consisting of 5'-dibenzo-2,2'-indotricarbocyanine barchlorate (Dejima in 2) and NrR-PA1006 (bisphenyldithiol Ni complex manufactured by Mitsui Toatsu Chemical Co., Ltd.) (lfiffi part) Layers were laid.

On top of this, a 0.3 mm thick sheet made of vinyl chloride resin and having recesses 3 mm wide and 3 mm apart was heat-sealed.

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 the drawing]

FIG. 1 is a sectional view of the optical card of the present invention. Explanation of symbols l...Optical card, 2...Substrate, 3...Recording layer, 4
...Protection member, 5...Void.

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 gap of 0.01 mm or more is formed between the optical recording section and the protective film. An optical card characterized by: