JPH03290780A - Steres bar code recording object and reading system for the same - Google Patents

Abstract

PURPOSE:To hold secrecy and to prevent forgery by providing a steres bar code, which is colorless and transparent in a visible light area, using an indium - stannum oxide or a stannum oxide on a substrate. CONSTITUTION:By attaching a thin film composed of the indium - stannum oxide or the stannum oxide onto a substrate 7 or coupling the powder of the indium - stannum oxide or of the stannum oxide onto the substrate 7 by coupling agent resin, a steres bar code 8 is provided to be completely colorless and transparent in the visible light area. When the substrate 7 of an ID card 6 to travel through a slit 3 and the steres bar code 8 are irradiated with infrared rays from a light emitting diode 1, the infrared rays irradiating the steres bar code 8 are reflected and the infrared rays irradiating the substrate 7 are transmitted and photodetected by a photodetector 2. Thus, the secrecy can be sufficiently held and the forgery can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stealth barcode recording medium provided with a stealth barcode that is colorless and transparent in the visible light region, and a reading method thereof.

[Prior Art] In recent years, optical means have been used to read barcodes printed on predetermined paper such as catalogs to determine the characteristics of the product.
It is used to obtain information such as prices, or to read the magnetic stripe magnetic barcode on prepaid cards, ID cards, etc. with a magnetic recording and reproducing device to obtain information such as amount, number of times, date, and other personal information. ing.

In such a case, if the barcode printed on the catalog or the like is a stealth barcode that cannot be seen with the naked eye, the catalog or other printed matter will be easier to see.

In addition, it is desirable that personal information recorded on the magnetic stripes of prepaid cards, ID cards, etc. be kept secret and difficult to forge. By doing so, secrecy can be maintained sufficiently and counterfeiting can be effectively prevented.

For this reason, stealth barcodes using phosphors that emit light in the infrared wavelength region are printed on printed materials such as catalogs to make them easier to read, as well as the characteristics of the products printed in the catalogs. Attempts are being made to make it possible to obtain information such as , prices, etc. (Tokuko 1977-
(No. 22326, Japanese Patent Publication No. 61-18231) [Problems to be Solved by the Invention] However, conventional stealth barcodes printed on catalogs, etc. using phosphors that emit light in the infrared wavelength region Because it is faintly colored, it is not completely colorless and transparent, and the barcode, which is supposed to be stealth, can be easily seen with the naked eye. For this reason, with conventional stealth barcodes using phosphors, when printed on printed matter such as catalogs, the printed matter becomes slightly difficult to see, and when printed with magnetic stripes on prepaid cards, ID cards, etc.
If the whereabouts of the indium-tin oxide are revealed, sufficient secrecy cannot be maintained, and counterfeiting cannot be effectively prevented. A thin film of indium-tin oxide or tin oxide is deposited on the substrate directly or through an ultraviolet absorbing layer by vacuum evaporation or the like, or indium-tin oxide or tin oxide powder is deposited on the substrate with a binder resin. By bonding directly or through an ultraviolet absorbing layer, a stealth barcode that is completely colorless and transparent in the visible light range can be created, making it possible to print on printed matter such as catalogs, prepaid cards, ID cards, etc. without making the print difficult to see. Also, it is possible to record information such as product characteristics, prices, and various personal information without knowing the location.

In addition, by irradiating this stealth barcode with infrared rays or reading the capacitance and conductivity using flow, etc., it can be printed on printed matter such as catalogs, prepaid cards, ID cards, etc. without making it difficult to see, and the location of the barcode can be known. Information such as product features and prices printed in catalogs, etc., as well as various personal information can be obtained from completely colorless and transparent stealth barcodes that are installed without being exposed. This ensures sufficient confidentiality and effectively prevents counterfeiting.

The present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a stealth barcode reading device that uses infrared rays. This stealth barcode reading device has a light emitting diode 1 that emits infrared rays and a light receiving element 2 that are vertically opposed to each other. A slit 3 is provided directly below the light receiving element 2, a slit 4 is provided above the light receiving element 2, and a filter 5 is further provided between the light receiving element 2 and the slit 4.

Reference numeral 6 denotes an ID card with a stealth barcode 8 provided on a substrate 7, which runs between a light emitting diode 1 and a light receiving element 2. During this time, infrared rays are emitted from the light emitting diode 1 and received by the light receiving element 2, resulting in a stealth bar code. 8 is read.

Here, the substrate 7 of the ID card 6 is made of a material that transmits infrared rays, such as a polyester film or a polypropylene film. In addition, the stealth barcode 8 can be made by depositing indium-tin oxide or tin oxide on the substrate 7 by vacuum evaporation or the like, or by depositing indium-tin oxide or tin oxide powder on an ultraviolet curable resin. or mixed with vinyl chloride-vinyl acetate copolymer, binder resin such as polyurethane resin, methyl ethyl ketone, tetrahydrofuran,
An oxide paint is prepared by mixing and dispersing it with an organic solvent such as ethyl cellosolve acetate, and this oxide paint is applied onto the substrate 7 and dried. reflect.

When the ID card 6 is run between the light emitting diode 1 and the light receiving element 2 and infrared rays are irradiated from the light emitting diode 1, the substrate 7 and stealth barcode 8 of the ID card 6 running through the slot 3 are struck. The infrared rays irradiated onto the stealth barcode 8 are reflected by the stealth barcode 8, and the infrared rays irradiated onto the substrate 7 are transmitted through the substrate 7, passed through the slit 4 and the filter 5, and are received by the light receiving element 2. . Then, the infrared light received by the light receiving element 2 is converted into an electrical signal, and as shown in FIG. 2, a fluctuating wave of output corresponding to the width of the stealth barcode 8 is obtained. The information is obtained and the stealth barcode 8 is read.

At this time, the infrared rays emitted from the light emitting diode 1 preferably have a wavelength center of 950 r+m and about 880 nm, and the light emitting diode 1 is a diode that can emit infrared rays with a wavelength center of 950 nra and about 8B0no+, for example. , CyaAs, GaAfAs, etc. are preferably used. In addition, the filter 5 is made of a material that cuts external light according to the wavelength of infrared rays.
A filter made of As absorbs light below 860 nm and transmits light above it, so when using infrared rays with wavelengths centered around 950 nm and 880 nm,
A filter made of 200aAs is used. In addition,
In addition, a commercially available filter having similar properties may be used in the form of a sheet film such as a plastic film.

FIG. 3 shows another example of a stealth barcode reading device that uses infrared rays. This stealth barcode reading device has a light emitting diode 1a that emits infrared rays and a light receiving element 2a that are tilted on both sides of a partition wall 9. A swan) 3a is provided directly below the light-emitting diode Ia, a swan h4a is provided below the light-receiving element 2a, and a filter 58 is further provided between the light-receiving element 2a and the slit 4a to emit light from the light-emitting diode la. When the traveling ID card 6 is irradiated with the infrared rays, it is reflected by the stealth barcode 8 on the substrate 7 and can be received by the light receiving element 2a.

In this case, the infrared rays reflected by the stealth barcode 8 are received by the light receiving element 2a and converted into electrical signals to obtain information about the width and spacing of the stealth barcode 8. be read.

Figure 4 shows another example of a stealth barcode reading device that uses infrared rays.
b and a light receiving element 2b are provided as appropriate, an optical fiber 10 is connected to the light emitting diode 1b, an optical fiber 11 is connected to the light receiving element 2b via a filter 5b, and the tips of the optical fibers 10 and 11 are placed on the running ID card 6. When the infrared rays emitted from the light emitting diodes 1b are irradiated onto the stealth barcode 8 on the substrate 7 of the ID card 6 traveling through the optical fiber 10, the stealth barcode 8 reflects the infrared light emitted from the light emitting diode 1b. The light receiving element 2b is transmitted through the optical fiber 11 and the filter 5b.
so that the light is received.

In this case, the infrared rays reflected by the stealth barcode 8 are received by the light-receiving element 2b via the optical fiber 10, and converted into electrical signals, which are then reflected by the stealth barcode 8.
information about the width and spacing of the bar code 8 is obtained and the stealth barcode 8 is read.

Figure 5 shows an example of a stealth barcode reading method that utilizes changes in capacitance. This stealth barcode reading method uses a pair of electrodes 12, 12 connected by wiring and to which a voltage is applied. , a pair of electrodes 12 arranged close to the running ID card 6 and to which a voltage is applied.
．． 12, the change in capacitance on the ID card 6 as it travels is measured. Such a change in capacitance is caused by a stealth barcode 8 made of a thin film of indium-tin oxide or tin oxide provided on the substrate 7 of the ID card 6, or a thin film of indium-tin oxide or tin oxide. Since the stealth barcode 8 containing the powder together with the binder resin has conductivity, when the pair of electrodes 12 and 12 reach the stealth barcode 8, the capacitance decreases and the stealth barcode 8 is formed. This occurs because the capacitance is different from that on the substrate 7, and this change in capacitance is measured.

In this case, a pair of electrodes 1 to which a voltage is applied
2.12, the change in capacitance when the ID card 6 that is running approaches the stealth barcode 8 is measured corresponding to the width of the stealth barcode 8, and The information is obtained and the stealth barcode 8 is read.

FIG. 6 shows another example of the stealth bar code reading method that utilizes changes in capacitance. is attached and connected, one electrode 14 to which a voltage is applied is brought into contact with this common electrode 13, and the other electrode 15 connected to the electrode 14 by wiring,
It is arranged close to the stealth barcode 8 of the ID card 6 that is traveling.

In this case, the other electrode 15 runs at the ID
When the stealth barcode 8 of the card 6 is brought close to the stealth barcode 8, the capacitance increases because the stealth barcode 8 has conductivity.
The change in capacitance above is measured. Since this change in capacitance corresponds to the width of the stealth code 8 of the ID card 6 that is running, information on the width and spacing of the stealth barcode 8 can be obtained, and the stealth barcode 8
is read.

FIG. 7 shows an example of a stealth barcode reading method that utilizes changes in current. In this stealth barcode reading method, each of the ID carts 6 running The traveling ID card 6 is brought into contact with the common electrode 13 attached to the stealth barcode 8, and the other electrode 17 connected to the electrode 16 by wiring.
The stealth barcode 8 of

In this case, the other electrode 17 runs on the ID
When it comes into contact with the stealth barcode 8 of the card 6, since the stealth barcode 8 is conductive, current is conducted.
On the other hand, even if the substrate 7 on which the still spur cord 8 is not formed is contacted, no current is conducted, so a change in the current conduction is measured. Since this change in conduction current corresponds to the width of the stealth barcode 8, information regarding the width and spacing of the stealth barcode 8 can be obtained and the stealth barcode 8 can be read.

Note that the ID card 6 is not limited to those shown in FIGS. 1 to 7, and in addition to providing the stealth barcode 8 on the substrate 7, a magnetic layer may be formed on a part of the substrate 7. Stealth barcode 8 on the magnetic layer formed on 7
In addition to providing the stealth barcode 8 directly on the substrate 7, an infrared absorbing layer may be provided on the substrate 7, and the stealth barcode 8 may be provided on this infrared absorbing layer. Since the infrared rays irradiated between the stealth barcodes 8 are better absorbed by the infrared absorbing layer, the contrast between the infrared rays reflected by the stealth barcodes 8 and the infrared rays transmitted between the stealth barcodes 8 is increased. The reading accuracy of the stealth barcode 8 is improved. Stealth barcode 8 provided on this sexual board 7
A topcoat layer that is colorless and transparent and transmits infrared rays may be further provided thereon. In this case, the topcoat layer protects the stealth barcode 8 and makes it difficult to get dirty and damaged.

For the infrared absorbing layer provided on the substrate 7, for example, an infrared absorbing agent such as a diimonium compound, CHCf:l, carbon powder, etc., an ultraviolet curable resin, a vinyl chloride-vinyl acetate copolymer, a polyurethane resin, etc. A binder resin, methyl ethyl ketone, methyl isobutyl ketone, toluene, tetrahydrofuran, and other organic solvents are mixed and dispersed to prepare an infrared absorbing paint, and this paint is applied onto the substrate 7 and dried to form a stealth barcode 8. The top coat layer to be further formed is prepared by preparing a top coat N paint by dissolving a binder resin such as an ultraviolet curable resin or a polyurethane resin in an organic solvent such as methyl isobutyl ketone or tetrahydrofuran. The stealth barcode 8 and board 7
It is formed by coating and drying.

In addition, in FIGS. 1 to 7 above, ID cards provided with stealth barcodes have been explained, but recording bodies provided with stealth barcodes are
Not limited to cards, prepaid carts,
It can be applied to anything that can be provided with a stealth barcode, such as printed materials such as bank cards, bankbooks, catalogs, etc., and has the same effect.

〔Example〕

Next, embodiments of the invention will be described.

Example 1 The length is 5.5 cm+, the width is 8.5 cm, and the thickness is 200 cm.
Predetermined printing is performed on a colorless and transparent polyester film of μm in size, and indium-
An ID card was made by vacuum-depositing tin oxide to create a stealth barcode made of indium-tin oxide in a predetermined shape with a thickness of 2,000 people and a width of 20 m.

The obtained ID card is passed through the stealth barcode reading device shown in Fig. 1 at a movement speed of 2°Own/see.
The infrared light emitting diode TLNl 13 (Ga
Infrared light emitting diode made of As, center wavelength 950n
Infrared rays with a center wavelength of 950 nra were irradiated from m)1.

A filter 5 made of GaAs with a thickness of 0.3 ann is passed through the slits 3 and 4 with a width of 0.3.
The infrared rays transmitted by the ID card 6 were received by a photodiode TPS612 (infrared receiving element made of silicon) 2, manufactured by Toshiba Corporation, located at a distance of 1.5 mm from the ID card 6, and converted into an electrical signal to read the stealth barcode.

Example 2 An ID card was made in the same manner as in Example 1, and this (7) I
The D card 6 is run through the stealth barcode reading device shown in FIG. 3 at a moving speed of 200 cm/sec.
Infrared light with a center wavelength of 950 na+ was irradiated at an incident angle of 30 degrees from an infrared light emitting diode TLNII3 (infrared light emitting diode made of GaAs, center wavelength 950 no+) la located 15 m from the ID card 6, manufactured by Toshiba Corporation.

Then, slits 3a and 4 with a slit width of 0.3 mm are used.
The infrared rays transmitted through the filter 5a made of GaAs with a thickness of 0.3 mm are transmitted through a photodiode TPS612 (manufactured by Toshiba Corporation) located at a distance of 15 mm from the ID card 6.
The light was received by an infrared light receiving element (2a) made of silicon and converted into an electrical signal to read the stealth barcode.

Example 3 An ID card was made in the same manner as in Example 1, and the ID card 6 was run at a moving speed of 20 an/sec using the stealth barcode reading device shown in FIG. TLN113 (GaAs
Infrared light emitting diode, center wavelength 950na+
) lb, infrared rays with a center wavelength of 950 nm were irradiated at a substantially vertical incident angle through an optical fiber 10 with a diameter of 0.1 ribs and a tip located at a distance of 1 m11 from the ID card 6. Then, the infrared rays are transmitted through a filter 5b made of GaAs with a thickness of 0.3 mm via an optical fiber 11 having a diameter of 0.15 mm and whose tip is at a distance of IIIlo from the ID card 6.
612 (infrared receiving element made of silicon) 2b received the light, converted it into an electrical signal, and read the stealth barcode.

Example 4 Indium-tin oxide powder 70 parts by weight (average particle size 2 μm) Polyurethane resin 30% Tetrahydrofuran 100% This composition was mixed and dispersed in a ball mill for 48 hours to prepare an oxide paint. Next, this oxide paint was applied onto a polyester film measuring 4.5 cm in length and 8.5 cm in width and having a thickness of 200 μm, which had been given a predetermined print, and was dried to form a film with a thickness of 1 μm and a width of 20 μm.
- A predetermined stealth barcode was formed to create an ID card.

Using the ID card thus obtained, a stealth barcode was read in the same manner as in Example 1.

Example 5 Using the ID card obtained in Example 4, a stealth barcode was read in the same manner as in Example 3.

When reading stealth barcodes in each example and comparative example, when the light passes through, the amount of light changes slightly due to the underlying printing, so the output is not constant, and when the light is reflected by the stealth barcode, the theoretical output is 0
However, due to dark current and some light passing through, a small amount of output is produced, so the output when passing through a stealth barcode is
Output I2 when passing through a part without stealth barcode
and I, /1. The ratio was calculated, and the average variation of the output (■1) when passing the stealth barcode was calculated.

Table 1 below shows the results.

Table 1 [Effects of the Invention] As is clear from Table 1 above, 1, /1. There is a sufficient difference in the ratio of Il, and the average variation of Il is small. Therefore, according to the stealth hard code recording medium and stealth barcode reading method obtained by this invention, it is possible to read stealth barcodes that are colorless and transparent in the visible light range. It can be seen that reading can be performed satisfactorily.

[Brief explanation of drawings]

FIG. 1 is a front view of the essential parts of an example of the stealth barcode reading device of the present invention, and FIG. 2 is a diagram showing the output waveform of the light receiving element when the stealth barcode reading device of FIG. 1 is used. 3 and 4 are front views of essential parts showing other examples of the stealth barcode reading device of the present invention, and FIGS. 5 to 7 show other examples of the stealth barcode reading method of the present invention. It is a schematic explanatory perspective view which shows an example. 1, Ia, Lb - light emitting diode, 2.2a.

Claims (1)

[Claims] 1. A stealth barcode that is colorless and transparent in the visible light range and is made of a thin film of indium-tin oxide or tin oxide, or a powder of indium-tin oxide or tin oxide together with a binder resin. A stealth barcode recording body 2 characterized in that a stealth barcode, which is colorless and transparent in the visible light region, is provided on a substrate, and an infrared absorbing layer is provided on the substrate, and an indium-absorbing layer is provided on the infrared absorbing layer. Stealth barcodes that are colorless and transparent in the visible light range, made of tin oxide or a thin film of tin oxide, or colorless and transparent in the visible light range, that are made of indium-tin oxide or tin oxide powder together with a binder resin. A stealth barcode recording body 3 characterized by having a stealth barcode provided thereon, made of a thin film of indium-tin oxide or tin oxide provided directly or via an infrared absorbing layer on the base of the stealth barcode recording body. A stealth barcode containing indium-tin oxide or tin oxide powder together with a binder resin is irradiated with infrared rays, and the reflected light from the irradiated infrared rays or between the stealth barcodes is A stealth barcode reading method 4 characterized in that a stealth barcode is read by transmitted light of a stealth barcode, a stealth barcode consisting of a thin film of indium-tin oxide or tin oxide provided on a base of a stealth barcode recording body, Alternatively, a pair of electrodes is brought close to a stealth barcode containing indium-tin oxide or tin oxide powder together with a binder resin, and the stealth barcode is read by the change in capacitance that occurs between the pair of electrodes. A stealth barcode reading method 5 characterized by a stealth barcode consisting of a thin film of indium-tin oxide or tin oxide provided on the base of the stealth barcode recording body, or a stealth barcode made of a thin film of indium-tin oxide or tin oxide. A stealth barcode comprising a powder together with a binder resin is attached and connected to the stealth barcode, with one electrode in contact with the common electrode and the other electrode in close proximity to the stealth barcode, thereby forming a connection between the two electrodes. Stealth barcode reading method 6, which is characterized by reading stealth barcodes by changes in capacitance that occur in the stealth barcode recording medium. A bar code, or a stealth bar code comprising indium-tin oxide or tin oxide powder together with a binder resin, is connected with a common electrode, with one electrode in contact with the common electrode and the other A stealth barcode reading method characterized by bringing an electrode into contact with the stealth barcode and reading the stealth barcode by changing the current conducted between the two electrodes.