JPH10171952A - Barcode, barcode system, its manufacture and method for reading barcode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barcode showing a high S/N, having a fine sensitivity and capable of sufficiently coping with a recording with a high recording density by including an organic compound having angle of rotation, detecting the angle of rotation and making information be readable. SOLUTION: In this barcode, the information can be read by including the organic compound having the angle of rotation and detecting that. Thus, the organic compound having the angle of rotation is used, but this angle of rotation means an angle in which the plane of polarization rotates according to the solid arrangement of optical active parts of a material, when a linear polarized light is irradiated to a compound which has optically active parts corresponding to the right-hand and left-hand rules in its molecule. Then, this phenomenon that the plane of polarization rotates is referred to as optical activity. The digital writing/reading of the information is realized using this characteristic and using the difference of the rotation angles of a barcode material painted part having angle of rotation and an unpainted part not having that.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a barcode, a barcode system using the barcode, a method of producing the barcode, and a method of reading the barcode.

[0002]

2. Description of the Related Art In recent years, the method of writing information using a bar code and taking out the information with a dedicated reader is easy and the cost is low.

For example, a system in which information specific to a product such as a price and a classification is written into the product itself using a barcode and read by a dedicated reading machine at a cash register is a system widely used mainly in large-scale stores. I have. It is also a well-known fact that many libraries use barcodes to manage information on collections, information on lending, information on users, and the like. Also, many companies use barcodes effectively to manage inventory and sales, or manage information about employees or customers. As you can see, barcodes already contain people, goods, prices,
It has become indispensable as a simple means of managing information and the like.

[0004] Barcode recording / reading methods are roughly classified into (1) a method utilizing light absorption, and (2) a method utilizing fluorescence emission by irradiation with excitation light.

The method (1) is a method of detecting the difference in reflected light intensity due to light absorption of a bar code by irradiating visible light, and most of the bar codes currently widely used absorb light well. Black composition is used. The greatest advantage of this method is that the apparatus and barcode material are inexpensive and the operation of the apparatus is simple. For this reason, it is now widely used in general applications. However, in this method, the intensity of reflected light due to light absorption is detected, so that the sensitivity does not become too high.

On the other hand, the method (2) is a method in which a bar code made of a composition to which a fluorescent substance is added is irradiated with light having an excitation wavelength of the fluorescent substance to detect the emission intensity of the fluorescent light.
The advantage of this method is that the signal can be digitally detected between the portion where the fluorescent substance is present and the portion where the fluorescent substance is not present because the light emission is monitored, so that the S / N ratio is high. The sensitivity is higher than that of the method 1). If the sensitivity is good, it is possible to sufficiently cope with a case where a barcode having a high recording density is used or a case where high-speed reading is required. However, in recent products, a fluorescent substance is often added in order to make the color vivid, and in such a case, fluorescence is detected even from a portion without a barcode.
In some cases, no signal could be detected, or information could not be read accurately.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has a high S / N ratio, has good sensitivity, and is sufficiently compatible with high-density recording. The aim is to provide a bar code to get.

[0008]

According to the present invention, there is provided a bar code comprising:
It contains an organic compound having an optical rotation, and can read information by detecting the optical rotation.

Further, a bar code system according to the present invention comprises a bar which includes a recording object and an organic compound provided on the recording object and having an optical rotation, and which reads out information by detecting the optical rotation. With code.

The method for producing a barcode system according to the present invention comprises, first, a step of dissolving an organic compound having an optical rotation in a solvent to prepare a coating solution, and using the coating solution on a recording object. Recording information by forming a predetermined code shape.

The method for producing a barcode system according to the present invention comprises, in a second step, a step of preparing a coating solution by dispersing an organic compound having an optical rotation in a polymer material; And recording information by forming a predetermined code shape using the method.

Third, in the method of manufacturing a barcode system of the present invention, a step of recording information by forming a predetermined code shape on a recording object using a polymer having a functional group having an optical rotation. Is provided.

Further, in the bar code reading method of the present invention, a bar code containing an organic compound having an optical rotation is provided on a recording object, and a bar code containing an organic compound having an optical rotation is converted into linearly polarized light by passing through a polarizer. And reading the information by splitting the light reflected through the barcode with a beam splitter and detecting its optical rotation.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The barcode of the present invention is formed using a recording material containing an organic compound having an optical rotation.

The bar code of the present invention may be substantially composed of an organic compound having an optical rotation. For example, it may be composed of an organic compound having the optical rotation dispersed in a polymer material.

A first preferred embodiment of the barcode of the present invention comprises an organic compound having an optical rotation and a polymer material in which the organic compound is dispersed.

In a second preferred embodiment of the barcode of the present invention, the organic compound having a rotation and the polymer material have no absorption in the visible light region. This gives a transparent barcode.

Further, the barcode system of the present invention includes a recording object and a barcode formed using a recording material containing an organic compound having an optical rotation and reading out information by detecting the optical rotation. .

The barcode system of the present invention may be formed directly on a recording object on which a barcode is to be formed.
A base material may be formed in advance on a recording object, and a barcode may be formed via the base material.

In a first preferred embodiment of the bar code system according to the present invention, a substance which becomes a mirror surface in the wavelength range of the reading light source is provided as a base material between the recording object and the bar code.

According to a second preferred embodiment of the bar code system of the present invention, a recording material which does not absorb the wavelength of the visible light and the light source for reading out and forms a bar code between the recording object and the bar code. Also, a polymer having a small refractive index and no optical rotation is provided as a base material. Thereby, both the barcode and the base material become transparent to visible light.

The barcodes according to the first and second preferred aspects can be appropriately combined with any of the barcode systems according to the first and second aspects.

As described above, in the present invention, an organic compound having an optical rotation is used. The optical rotation means that when linearly polarized light is incident on a compound having an optically active site corresponding to the right-hand / left-hand relationship in the molecule, the plane of polarization rotates in a fixed direction due to the configuration of the optically active site of the substance. Refers to the angle. Further, such a phenomenon that the plane of polarization rotates is called optical rotation.

In the present invention, utilizing this characteristic, digital writing / writing of information is performed by utilizing the optical rotation difference between the coated portion of the barcode material having the optical rotation and the uncoated portion having no optical rotation.
Implement reading.

The organic compound having an optical rotation used in the present invention is one that can be dissolved in a solvent for spraying and applied uniformly, or can be uniformly applied to a polymer material as a structural support. Any material that can be dispersed may be used. The magnitude of the optical rotation may be any value as long as the plane of polarization of the signal light that has passed through the sample rotates and is separated by a beam splitter and can be detected by a photodetector.
The value of (α) is suitably 2.0 ° or more, preferably 20.0 ° or more.

The organic compound having an optical rotation is preferably azafurin, ajumarin, abietic acid, α-amyrin, α-ionone, isohydrobenzoin, 1-isoborneol, d-isomenthol, d-isomentone, β-erythroidine. , 1-β-cadinene, d-trans-carboeol, 1-carbomenthol, d-carvone, quinidine, chlorophyll, erythrocinnamic acid dibromide, cholesterol, d-zavinel, trans-
1,2-cyclopropanedicarboxylic acid, trans-1,
2-cyclohexanedicarboxylic acid, trans-1,2-
Cyclopentanedicarboxylic acid, N, N'-diphenyl-
1,2-propanediamine, d-camphor, camphorquinone, cinchonidine, timosterol, 7-dehydrocholesterol, d-α-terpineol, 3-hydroxy-3-phenylpropionic acid, d-α-pinene,
d-β-pinene, 1-phenyl-ethanol, 1-phenyl-2-propanol, 2-phenylpropionic acid,
3-buten-2-ol, propylene oxide, 2-bromopentane, poplin, d-2-bornylamine, d
-Borneol, mandelic acid, mandelonitrile, mannol, trans-2-methyl-l-cyclohexanol, 2-methyl-l-cyclohexanone, 3-methyl-
1-cyclohexanone, 2-methylpiperidine, d-3
-P-menthen, i-1-p-menthen, 1-menthone, d-linalol, or asparagine, aspartic acid, alanine, arginine, isoleucine, ethionine, ornithine, kynurenine, glutamine, glutamic acid, cysteine, cystine, citrulline, It is selected from amino acids such as serine, tryptophan, threonine, valine, histidine, hydroxyproline, phenylalanine, proline, methionine, lysine, leucine, and derivatives thereof.

The polymer material for dispersing the organic compound having an optical rotation may be any as long as it is transparent and has a film forming ability.
Preferably it is between 2 and 1.6. Preferred polymer materials are aniline resin, polydiallyl phthalate, polysilane, polysiloxane, polyvinyl formal, polyethylene, allyl resin, polymethylstyrene, polypropylene, polymethacrylate, polyacrylate, polyester, polystyrene, polyvinyl acetate , Cellulose acetate, polyvinyl chloride, epoxy resin,
It is selected from phenolic resins, polyacetals, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polychlorotrifluoroethylene, polyamide and the like. The ratio of the organic compound having an optical rotation to be dispersed in the polymer material is 2 to 60% by weight, preferably 5% by weight, based on the polymer material to be dispersed.
Suitably, it is set to ５０50% by weight.

As an organic compound having an optical rotation,
According to the first barcode preparation method, select a compound having a large optical rotation and having no absorption in the visible region, dissolve in a solvent and spray uniformly, or use a polymer material transparent in the visible region. According to the second barcode manufacturing method of the present invention, the polymer material can be uniformly dispersed and used.

In this case, since the visible light is transmitted even in the barcode material-coated portion, a colorless and transparent barcode according to the second preferred embodiment of the barcode of the present invention can be obtained. Information that exists on the entire surface such as mail or printed matter and cannot be hidden with a barcode, or when it is a confidential matter that the barcode is used to record information, or a security check For example, such a bar code having high transparency is effective.

As an organic compound having an optical rotation for a transparent bar code, a polymer which does not absorb in the visible light range, can be dissolved in a solvent and can be sprayed uniformly, or is used as a structural support Any material can be used as long as it can be uniformly dispersed in the material. The magnitude of the optical rotation may be any value as long as the plane of polarization of the signal light that has passed through the sample rotates and can be detected by the photodetector 7 after being separated by the beam splitter. Suitably, it is 2.0 ° or more, preferably 20.0 ° or more.

As such an organic compound, for example, 1
-Isoborneol, d-isomenthol, d-isomentone, d-trans-carboeol, 1-carbomenthol, cholesterol, trans-1,2-cyclopropanedicarboxylic acid, trans-1,2-cyclohexanedicarboxylic acid, trans-1 , 2-Cyclopentanedicarboxylic acid, N, N'-diphenyl-1,2-propanediamine, d-camphor, camphorquinone, 7-dehydrocholesterol, d-α-terpineol, 3-
Hydroxy-3-phenylpropionic acid, d-α-pinene, d-β-pinene, 1-phenyl-ethanol, 1-
Phenyl-2-propanol, 2-phenylpropionic acid, 3-buten-2-ol, propylene oxide, d
-2-bornylamine, d-borneol, mandelic acid, trans-2-methyl-1-cyclohexanol,
2-methyl-1-cyclohexanone, 3-methyl-1-
Cyclohexanone, 2-methylpiperidine, or
Asparagine, aspartic acid, alanine, arginine, isoleucine, ethionine, ornithine, kynurenine, glutamine, glutamic acid, cysteine, cystine, citrulline, serine, tryptophan, threonine, valine, histidine, hydroxyproline, phenylalanine, proline, methionine, lysine, leucine, etc. And amino acids and derivatives thereof.

The polymer material which can be used for the transparent bar code and in which the organic compound having optical rotation is dispersed is not particularly limited as long as it has no film absorption in the visible light region and has a film forming ability. It is preferably between 1.3 and 1.6.

Examples of such polymer materials used for transparent barcodes include polysilane, polysiloxane, polyethylene, polymethylstyrene, polypropylene, polymethacrylate, polyacrylate, polyester, polystyrene, and polyvinyl acetate. , Polyvinyl chloride, epoxy resin, polyacetal, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polychlorotrifluoroethylene, polyamide and the like. The ratio of the organic compound having an optical rotation dispersed in the polymer material is 2 to 60% by weight, preferably 5 to 50% by weight based on the polymer material.
It is appropriate to use% by weight.

According to the present invention, the portion where the barcode material is applied has optical rotation, but the portion where the barcode material is not present basically has no optical rotation. However, when the object to be recorded is an optically active object, even in a portion without barcode material, the optical rotation is present, so that digital information cannot be read out, and the S / N ratio is greatly reduced. hand,
In some cases, reading may not be possible at all, or accurate reading of information may not be possible. In such a case, the influence of the optical rotation of the recording object can be eliminated by pre-coating an underlayer that does not absorb reading light at all and has high flatness.

In the first preferred embodiment of the barcode system of the present invention, any material that can be used as a base can be used as long as it does not absorb reading light and forms a mirror surface. Preferably, a metal such as aluminum, gold, silver, and tin forming a foil and an alloy compound thereof, or an optically inactive polymer material forming a layer having a lower refractive index than the composition forming a barcode is selected. Is done.

As such a polymer material, a material having a refractive index of preferably between 1.4 and 1.7 can be used. Preferred polymer materials include polydiallyl phthalate, polysilane, polysiloxane, polyethylene, allyl resin, polymethylstyrene, polypropylene, polymethacrylate, polyacrylate, polyester, polystyrene, polyvinyl acetate, cellulose acetate, epoxy resin, Phenolic resin, polyacetal,
Polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, acrylonitrile-styrene copolymer,
Acrylonitrile-butadiene copolymer, polyamide and the like can be mentioned.

In the case where the surface of the object to be recorded has extremely large irregularities and the intensity of the signal light entering the detection system cannot be increased, the above-described undercoat is applied regardless of the presence or absence of the optical rotation of the object to be recorded. Is preferred.

The second preferred embodiment of the bar code system of the present invention is preferably used when the object to be recorded has an optical rotation, and does not absorb the visible region and the light for reading out at all. By applying in advance an optically inactive base polymer material constituting a layer having a lower refractive index than the composition constituting the code, it is possible to secure transparency and eliminate the influence of the optical rotation of the object to be recorded. it can.

The material that can be used as the base preferably has a refractive index of between 1.4 and 1.7. Preferred materials include, for example, polysilane, polysiloxane, polyethylene, allyl resin, polymethylstyrene,
Polypropylene, polymethacrylate, polyacrylate, polyester, polystyrene, polyvinyl acetate, cellulose acetate, epoxy resin, polyacetal, polyvinyl alcohol, polyvinyl butyral,
Acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer and the like can be mentioned.

Even when the surface of the object to be recorded has very large irregularities and the signal light entering the detection system cannot have a sufficient intensity, it is preferable to apply the above transparent base.

According to the present invention, information can be written by printing a predetermined code on an object to be recorded using an organic compound having an optical rotation.

As a method of writing information by printing as described above and producing a bar code system, for example, the following method can be mentioned.

The first method for preparing a bar code system includes a step of dissolving an organic compound having an optical rotation in a solvent to prepare a coating solution, and a step of forming a predetermined code shape on a recording object by using the coating solution. And a step of recording information by forming a bar code.

As a second method for producing a bar code system, a step of dispersing an organic compound having an optical rotation in a polymer material to prepare a coating solution, and using this coating solution on a recording object, Recording information by forming a predetermined code shape.

As a third method for producing a barcode system, a polymer material having a functional group having an optical rotation is used,
A barcode manufacturing method includes a step of recording information by forming a predetermined code shape on a recording target.

Examples of the polymer material having a functional group having an optical rotation used in the third method for producing a barcode system include 1-isoborneol, d-isomenthol, and 1-isomenthol on the side chain of polymethacrylic acid. Carbomenthol, d-
α-terbioner, 1-phenyl-2-propanol, 3-buten-2-ol, d-borneol, or asparagine, tolulin, serine, tryptophan, threonine, valine, histidine, hydroxyproline, phenylalanine, proline, methionine, lysine, Polyacrylic acid esters with amino acids such as leucine, or 2
-Cyclopropanedicarboxylic acid, trans-1,2-cyclopentanecarboxylic acid, 3-hydroxy-3-phenylpropionic acid, mandelic acid or asparagine;
Polymer materials to which amino acids such as tolulin, serine, tryptophan, threonine, valine, histidine, hydroxyproline, phenylalanine, proline, methionine, lysine, and leucine are added are exemplified.

Further, since the above-mentioned examples of the polymer material having a functional group having an optical rotation are all polymer materials having no absorption in the visible light region, they can also be used as a transparent barcode material. .

According to the present invention, a bar code made of a recording material containing an organic compound having an optical rotation provided on a recording object and having a linearly polarized light for reading through a polarizer is read. And a step of reading information by separating the light reflected via the barcode with a beam splitter and detecting the rotation of the light, that is, detecting the rotation of the polarization plane. Is provided.

FIG. 1 is a diagram for explaining an example of a bar code reading method according to the present invention.

As shown in FIG. 1, in the apparatus for reading a bar code according to the present invention, a light source 1, a collimator lens 2, and a polarizer 3 are arranged such that light from the light source
2 are sequentially arranged so as to enter at a predetermined angle. The barcode 12 is displayed on the recording object 10.
It is formed with the reflection layer 11 interposed.

The light from the light source is collimated by the collimator lens 2, passes through the polarizer 3, and becomes linearly polarized light.
The bar code recording area 4 is irradiated. The emitted light is
In the bar code material uncoated portion 13, the light is directly reflected on the reflective layer 11, and in the bar code applied portion 12, the light passes through the inside and is reflected by the reflective layer 11.

The polarizer 5, the beam splitter 6, and the photodetector 8 composed of a photodiode allow the light reflected by the barcode material-uncoated portion 13 to pass therethrough and be detected by the photodetector 8. Placed in The photodetector 7 is arranged so as to detect only the reflected light that passes through the barcode 12 and is divided by the beam splitter 6.

The reflected light directly reflected on the reflection layer 11 is
The light passes through the polarizing plate 5 and completely passes through the beam splitter 6, and is thereafter detected by the photodetector 8. Barcode 12
The light reflected by passing through the mirror has a rotation angle in the polarization plane of the beam when passing through, and is split by the beam splitter 6,
The light is detected by the light detector 7.

When the optical rotation of a portion where information is recorded is scanned by using such an apparatus, the bar code material applied portion 12 (with optical rotation: signal 1) and the bar code material uncoated portion 13 (without optical rotation: Since the signal of signal 0) can be digitally detected by the photodetector 7, the S / N ratio can be dramatically improved as compared with a conventional recording / reading method using a barcode material.

As a light source for reading information, any light source may be used as long as it emits light in a wavelength range where the barcode material has no absorption. However, when the undercoat is applied in advance, the light must be in a wavelength range that is not absorbed by the material constituting the undercoat. In consideration of downsizing of the device and stability and cost of the light source, a laser diode having an emission wavelength range of 450 nm to 700 nm is preferable.

The barcode and its reading method can be applied in all fields where barcodes are currently used. In addition, since it is digital writing, it can be applied to all fields where high-speed signal reading such as postal code reading is required and all fields where a high S / N ratio is required. further,
When a transparent barcode is used, information exists on the entire surface of the object to be recorded, and it is impossible to cover it with a colored barcode, or when it is a confidential matter that the barcode is recorded Alternatively, the present invention can also be applied to a case where it is used for a security check.

[0057]

The present invention will be described below in detail with reference to examples.

Example 1 2-phenylpropionic acid (R-form: (α) =-93.1)
(Measurement solvent: benzene) 0.5 g and polymethyl methacrylate (5 g) were dissolved in acetone (50 ml) and stirred well until uniform. After leaving the polymer composition still to remove air bubbles, the thickness is 50, 75, 100, 125, 150, 17
Films of 5 μm and 200 μm were formed and dried under reduced pressure to completely remove the solvent. Using these films,
1 mm in a recording space of size cm × 2 cm
A bar code having a line-and-space pattern in which bar code material application portions having a width of 2 mm, 3 mm, 4 mm, and 5 mm were arranged at 1 mm intervals was produced.

The reading of information was performed by, for example, an apparatus having a configuration as shown in FIG.

Here, using a laser diode (ZnSe _0.36 Te _0.64 ) as the light source 1, the wavelength of 630 nm is converted into parallel light by the collimator lens 2, then converted into linearly polarized light through the polarizing plate 3, and recorded on paper. The bar code 4 is irradiated. If the optical system is arranged so that the light reflected by the barcode material-uncoated portion 13 completely passes through the beam splitter 6 after passing through the polarizing plate 5 and all the light is detected by the photodetector 8, Light is output to the photodetector 7 only when a rotation angle occurs in the polarization plane of the beam in the barcode material application section 12.

While scanning the barcode recording portion 4 at 10 m / sec, the intensity of light output to the photodetector 7 was monitored at 1 μs intervals, and replaced with 0 and 1 signals on a computer to reproduce recorded information. The information reading error at the time was measured. Table 1 shows the measured information reading error as an error width with respect to the original barcode width.

[0062]

[Table 1]

As is clear from Table 1, when the thickness of a bar code containing an organic compound having an optical rotation of 10% by weight with respect to the resin is 125 to 200 μm, the reading error is good, but 100 μm. Then somewhat good, 50μ
In the case of m and 75 μm, it is slightly defective.

Example 2 The weight of 2-phenylpropionic acid (R
Body: (α) =-93.1 ° Measurement solvent; benzene) and 5 g of polymethyl methacrylate were dissolved in 50 ml of acetone, and the mixture was stirred well until it became homogeneous. After leaving the polymer composition still to remove air bubbles, a 200 μm thick film was formed and dried under reduced pressure to completely remove the solvent. Using these films, 1 mm, 2 mm, 3 mm, 4 mm, 5 m
A barcode having a line & space type pattern in which barcode material application portions having a width of m were arranged at 1 mm intervals was produced.

The reading of information was performed in the same manner as in the first embodiment.

The information reading error of the bar code recording portion was measured in the same manner as in Example 1. The obtained information reading error is shown in Table 2 below as an error width with respect to the original barcode width.

[0067]

[Table 2]

As is clear from Table 2, when the amount of the organic compound having the optical rotation is 1% by weight with respect to the polymer material in which the organic compound is dispersed, it is slightly poor and 2% by weight.
Is somewhat good, and 5% by weight or more is good.

Example 3 2-phenylpropionic acid (R-form: (α) =-93.1)
(Measurement solvent: benzene) 0.5 g and resin 5 shown in Table 3
g was dissolved in 50 ml of acetone and stirred well until uniform. After leaving the polymer composition still to remove air bubbles, a film having a thickness of 200 μm was formed and dried under reduced pressure.
The solvent was completely distilled off. Using these films,
1 mm in a recording space of size cm × 2 cm
A barcode having a line & space pattern in which barcode material-applied portions having a width of 2 mm, 3 mm, 4 mm, and 5 mm were arranged at 1 mm intervals was produced.

The reading of information was performed in the same manner as in the first embodiment.

The information reading error of the bar code recording portion was measured in the same manner as in Example 1. The obtained information reading error is shown in Table 3 below as an error width relative to the original barcode width.

[0072]

[Table 3]

As is clear from Table 3, good reading is possible even when the organic compound having the optical rotation is dispersed using any resin.

Example 4 0.5 g of a compound having an optical rotation shown in Table 4 and 5 g of polymethyl methacrylate were dissolved in 50 ml of acetone, and the mixture was thoroughly stirred until the mixture became homogeneous. After leaving the polymer composition still to remove air bubbles, a 200 μm thick film was formed and dried under reduced pressure to completely remove the solvent. Using these films, 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm were placed in a recording space having a size of 2 cm × 2 cm.
A bar code having a line-and-space pattern in which bar code material-applied portions having a width of 1 mm are arranged at 1 mm intervals was produced.

The reading of information was performed in the same manner as in the first embodiment.

The information reading error was measured in the same manner as in Example 1. The measured information reading error is shown in Table 4 below as an error width with respect to the original barcode width.

[0077]

[Table 4]

As is clear from Table 4, in the case of 2-methyl-1-cyclohexane having an optical rotation (α) of less than 20 °, the reading error was slightly poor, and in the case of + 38.1 °, the reading error was slightly good. .1 °, + 87.6 ° and -18
In the case of 7.9, good results are obtained.

Example 5 As a substance to be recorded, a paper impregnated with 1-phenyl-2-propanol (R-form: [α] = + 30.2 ° measuring solvent; chloroform) was used, and a polyester (polyester) was previously set in the recording space. A refractive index of 1.57) was applied and dried well.
The film thickness of this base material was 100 μm. 2-phenylpropionic acid (R-form: [α] = − 93.1 ° measurement solvent;
0.5 g of benzene) and 5 g of polymethyl methacrylate (refractive index: 1.49) were dissolved in 50 ml of acetone, and thoroughly stirred until the mixture became homogeneous. After leaving the polymer composition still to remove air bubbles, a film having a thickness of 200 μm was formed.
After drying under reduced pressure, the solvent was completely distilled off. Using these films, a line & space type pattern in which 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm width bar code material application portions are arranged at 1 mm intervals in a recording space of 2 cm × 2 cm. A bar code having was prepared.

The reading of information was performed in the same manner as in the first embodiment.

As a result of measuring the information reading error in the same manner as in Example 1, there was no information reading error, and the original bar code pattern was reproduced.

[0082]

As described above, according to the present invention, it is possible to provide a bar code which has a remarkably improved S / N ratio, good sensitivity, and can sufficiently cope with high-density recording. .

Further, according to the present invention, a system free from erroneous signal reading can be realized in a field where high-speed signal reading is required.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a barcode reading method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Collimator lens 3, 5 ... Polarizer 4 ... Barcode recording part 6 ... Beam splitter 7, 8 ... Photodetector 10 ... Recording target 11 ... Reflective layer 12 ... Barcode coating part 13 ... Barcode material Uncoated part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G06K 7/12 G06K 7/12 Z

Claims (10)

[Claims] 1. A bar code comprising an organic compound having an optical rotation and reading out information by detecting the optical rotation. 2. The barcode according to claim 1, further comprising a polymer material in which the organic compound is dispersed. 3. The organic compound and the polymer material,
3. The barcode according to claim 2, wherein the barcode has no absorption in a visible light region. 4. A barcode system comprising a recording target and an organic compound provided on the recording target and having an optical rotation, and further comprising a barcode for reading out information by detecting the optical rotation. 5. The bar code system according to claim 4, wherein a material that becomes a mirror surface in a wavelength range of a reading light source is provided as a base material between the recording object and the bar code. . 6. A polymer that does not absorb visible light and the wavelength of a reading light source between the recording object and the barcode, has a smaller refractive index than the barcode, and has no optical rotation. The barcode system according to claim 4, wherein the barcode system comprises: 7. A method for preparing a coating solution by dissolving an organic compound having an optical rotation in a solvent, and recording information by forming a predetermined code shape on a recording object using the coating solution. And a method of manufacturing a bar code system. 8. A process of preparing a coating solution by dispersing an organic compound having an optical rotation in a polymer material, and forming information by forming a predetermined code shape on the recording object using the coating solution. Recording a bar code. 9. A method of manufacturing a barcode system, comprising a step of recording information by forming a predetermined code shape using a polymer having a functional group having an optical rotation on a recording object. 10. A linearly polarized readout light passing through a polarizer is incident on a barcode provided on a recording object and containing an organic compound having an optical rotation, and is transmitted through the barcode. The reflected light is split by a beam splitter,
A bar code reading method including reading information by detecting the optical rotation.