JP2003132484A - Method for improving recognition accuracy of object, equipment to be used therefor, and system using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for improving recognition accuracy of an object without altering a device utilizing infrared rays and further to provide equipment for implementing this method and a system using these pieces of equipment and method at low cost. SOLUTION: In the system for recognizing an object by sensing infrared rays, the method for raising accuracy in recognizing that the object contains glass flakes is provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a shape of an object,
A system using an infrared detector that recognizes / identifies a code or sign, for example, an intelligent transportation system (hereinafter,
(ITS)) or a POS system and the like, and to a method for increasing the recognition accuracy or the identification accuracy. Furthermore, the present invention relates to a device used in the method and various systems using the method.

[0002]

2. Description of the Related Art In ITS, it is necessary to accurately read letters and numbers on a license plate in order to identify each vehicle body. An infrared camera is used as the reading device, and the recognition accuracy is proportional to the sensitivity of the infrared camera and the amount of infrared light reflected from the license plate. Also, PO
Even in the S system, it is necessary to accurately read the barcode attached to the product or its packaging, and an infrared camera or an infrared detector is also used as the reading device. Furthermore, infrared cameras or infrared detectors are also used in systems that recognize the outer shape or presence of an object using transmitted light or reflected light. Since these are non-contact type, recognition processing time is short. It has very advantageous characteristics as an inspection device for industrial products.

[0003]

A high-sensitivity infrared camera may be used in order to improve the recognition accuracy of the device using infrared rays, but this increases the development cost of the entire system. In addition, since the high-sensitivity infrared camera responds to even a small amount of light, the ITS is used for applications where the usage environment changes greatly, especially outdoors, day or night.
In such cases, the recognition accuracy may decrease.

The present invention has been made by paying attention to such problems. It is an object of the invention to provide a method for improving the recognition accuracy of an object without improving an apparatus using infrared rays. Furthermore, it is to inexpensively provide a device for carrying out this method, and a system using these devices and methods.

[0005]

In order to achieve the above object, a method for improving recognition accuracy of the invention according to claim 1 is
In a system that senses infrared rays and recognizes objects,
The object contains glass flakes.

The method of improving recognition accuracy of the invention described in claim 2 is the method according to claim 1, wherein the glass flakes have silver (Ag), titanium nitride (TiN), titanium dioxide (TiO ₂ ) on the surface thereof. , Cobalt oxide (Co0), iron oxide (Fe ₂ O ₃ ), chromium oxide (Cr ₂ O ₃ ), indium oxide (In ₂ O ₃ ), tin oxide (Sn
O ₂ ), zinc oxide (ZnO) or antimony oxide (SbO) is a main component.

According to a third aspect of the present invention, in which the recognition accuracy is improved, the glass flakes have a composition of 0.1% iron oxide (Fe ₂ O ₃ ) in the first or second aspect of the invention.
~ 2 wt%, cerium (CeO ₂ ) 1-2 wt%, and cobalt oxide (CoO) 0-200ppm and selenium (Se)
0 to 20 ppm or nickel oxide
It contains 100 to 1,000 ppm of (NiO).

A method for improving the recognition accuracy of the invention according to claim 4 is the method according to any one of claims 1 to 3, wherein the glass flakes have an average particle size of 10 to 4,000 μm.
m, and an average thickness of 0.1 to 20 μm.

In the license plate of the fifth aspect of the present invention, glass flakes that reflect infrared rays are present in the letters or numbers.

In the license plate of the invention described in claim 6, the glass flakes reflecting infrared rays are present in the character or numeral portion, and the glass flakes absorbing infrared rays are present in the peripheral portion thereof.

In the bar code of the seventh aspect of the present invention, the glass flakes that reflect infrared rays are present in the code portions or in the intervals thereof.

In the bar code of the eighth aspect of the present invention, the glass flakes that reflect infrared rays are present at either the code portion or the interval thereof, and the glass flakes that absorb infrared rays are present at the other side. .

The package film of the invention described in claim 9 contains glass flakes that reflect infrared rays.

The ITS of the invention described in claim 10 uses the method described in any one of claims 1 to 4.

The POS system of the invention described in claim 11 uses the method described in any one of claims 1 to 4.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail.

The present invention is a method of increasing the recognition accuracy of an infrared detector by adding glass flakes to the object in a system for detecting infrared rays to recognize the object without particularly improving the infrared detector. Here, the object is a license plate or a vehicle body coating film in the ITS, and a bar code or a package film in the POS system. Glass flakes are flaky glass flakes, have an extremely large specific surface area, and have extremely high surface smoothness,
The reflected light has directivity, and strong reflected light can be obtained.
The means for incorporating the glass flakes into the object is not particularly limited, and the optimum means can be found by appropriately combining known means according to the form of the object. However, regardless of the shape of the object, it is desirable to arrange the smooth surfaces of the glass flakes so as to be along the surface of the portion where the reflected light is desired to be enhanced. By aligning the smooth surfaces of the individual glass flakes in the same direction,
This is because the reflected light becomes stronger. For example, when the object is a resin composition, if the glass flakes are kneaded in the resin in advance and injection-molded, the glass flakes will naturally be laminated along the outer surface of the resin composition. Strongly reflected light is obtained on all outer surfaces of. Also,
In order to increase the reflected light at a specific portion of the resin composition, or the letter or number portion of the license plate or the code portion of the bar code or its interval, glass flakes should be mixed in the ink or paint applied to the relevant portion. , They can be used according to standard methods. The glass flakes contained in the ink or paint are layered with smooth surfaces aligned along the surface of the object when the solvent is removed, so the reflected light at the place where it is applied is specifically enhanced. be able to. Therefore, the presence of the glass flakes only in the letter or number portion of the license plate or the code portion of the bar code or the interval thereof makes it possible to increase the reflected light at that portion, and improve the infrared detector in each of the above systems. Without doing
The recognition accuracy can be improved.

On the other hand, some glass flakes absorb infrared rays. The recognition accuracy can be further enhanced by using a combination of such infrared ray absorbing material and infrared ray reflecting material. For example, in the case of a license plate, if glass flakes that reflect infrared rays are placed in the numbers and letters and glass flakes that absorb infrared rays are placed in the periphery, the difference in infrared reflectance at the boundaries between the numbers and letters will be reduced. It becomes even larger and the recognition accuracy becomes higher.

The glass flakes have an infrared reflecting function or an infrared absorbing function. As a means of ensuring the infrared reflection function, silver (A
g), titanium nitride (TiN), titanium dioxide (TiO ₂ ), cobalt oxide (Co 0), iron oxide (Fe ₂ O ₃ ), chromium oxide (Cr ₂ O ₃ ), indium oxide (In ₂ O ₃ ), oxidation It can be mentioned that a thin film containing tin (SnO ₂ ), zinc oxide (ZnO) or antimony oxide (SbO) as a main component is provided. Among them, silver (Ag) is preferable because it has a large difference in refractive index from glass and has a high infrared reflectance. In addition, "to be a main component" means that the content rate of a composition component is 50 weight% or more. The thickness of this thin film is not particularly limited, but is preferably 50 to 150 nm. When the thickness is less than 50 nm, the function as an alkali barrier film becomes insufficient, so that the alkali component eluted from the glass flakes may deteriorate the resin composition or the paint over time. On the other hand, even if it is thicker than 150 nm, the infrared reflectance does not change much, so
This is disadvantageous in terms of film forming time or cost.

Further, as a means for ensuring the infrared absorbing function, iron oxide (Fe ₂ O ₃ ) is used as a composition component of glass flakes.
0.1 to 2% by weight, cerium (CeO ₂ ) 1 to 2% by weight, and cobalt oxide (CoO) 0 to 200 ppm and selenium (Se) 0 to 20 ppm, or Alternatively, it may be included that the nickel oxide (NiO) content is 100 to 1,000 ppm. Iron oxide and cerium are essential components for ensuring the infrared absorption function. When the iron oxide content is less than 0.1% by weight or the cerium content is less than 1% by weight, the infrared absorptivity of the glass flakes is not improved so much. On the other hand, if their content exceeds 2% by weight, the physical properties of the glass change significantly, making it difficult to form glass flakes. Further, it is preferable to use cobalt oxide and selenium in combination, and when they are not used, nickel oxide can be substituted.

The shape of the glass flakes is not particularly limited, but an average particle diameter of 10 to 4,000 μm and an average thickness of 0.1 to 20 μm are preferable. The glass flakes need to have a strength to withstand the pressure when the thermoplastic resin is injection-molded, and if they are too large, too thick, or too thin, they are easily crushed and cannot maintain a certain particle size. Further, the larger the average particle diameter, the higher the directivity and the stronger the reflected light in the specific direction, but on the other hand, the particle feeling of the glass flakes becomes too conspicuous, which may impair the original appearance of the coating film or the resin composition. Therefore, it is preferable to use glass flakes having the above-mentioned average particle size and average thickness.

The license plate in which the glass flakes reflecting infrared rays are present in the letter or number portion is not particularly limited in its structure and manufacturing method. For example, ink or paint containing glass flakes may be applied to the letter or number portions stamped and formed on the surface of the metal plate, or an adhesive film containing glass flakes may be attached to those portions. Good. Alternatively, a resin containing glass flakes may be molded into a desired letter or numeral shape, and these may be appropriately combined and bonded on a metal plate. Furthermore, when the glass flakes that reflect infrared rays and the glass flakes that absorb infrared rays are used in combination, an ink, paint or adhesive film containing the glass flakes that absorbs infrared rays is applied to the entire surface of the metal plate or It may be pasted, and a coating material containing glass flakes that reflect infrared rays may be applied from above by the above-mentioned means.

The form and manufacturing method of the bar code in which the glass flakes are present in either the code part or the interval thereof are not particularly limited. For example, a bar code is printed directly on a magazine or the like, and food or the like is often printed on a package container or a package film. In addition, it may be printed on the surface of the adhesive seal and attached to the product or the packaging container. By providing the glass flakes that reflect infrared rays only in one of the code portion of the barcode or the interval thereof, the recognition accuracy of the barcode can be improved. Black ink is usually used for the code part of the barcode, so glass flakes that reflect infrared rays
It is preferable that the bar code exists in the interval of the code part of the bar code. To make glass flakes reflecting infrared rays exist only in the space between the code parts of the barcode, form a base film containing the glass flakes on the entire printing surface before printing the barcode, or use a package film. If so, it can be realized by including glass flakes in the film. After that, if you print the barcode using black ink, etc., most of the infrared light will be absorbed by the black ink in the code part of the barcode, so glass that reflects infrared light only in the interval of the code part of the barcode. Flakes can be placed. Further, in order to further improve the recognition accuracy of the barcode, glass flakes that absorb infrared rays may be arranged in the code portion of the barcode. In order to arrange the glass flakes on the code portion of the barcode, the glass flakes may be mixed with the printing ink in advance and then the printing may be performed. In order to enhance the design of the product packaging, it is preferable to place glass flakes that reflect infrared rays in the code portion of the bar code, contrary to the case of the black ink, when the code portion of the bar code is illuminated.

Furthermore, when the shape of a product such as a resin molded product is inspected and controlled by using an infrared detector, infrared rays can pass through the object by incorporating glass flakes into the product or the coating film of the product. Since it is possible to prevent this or to completely reflect it on the surface, it is possible to reliably inspect the outer shape of the product in detail. Further, by using the infrared detector as described above, it is possible to inspect a large number of products in a short time.

When glass flakes are blended with ink or paint, the content of glass flakes with respect to the total solids (including glass flakes) of the ink or paint is 30 to 30.
It is preferably 60% by weight. The concentration of glass flakes in the ink or coating solution is preferably 5 to 30% by weight. If the content of the glass flakes is too high, the glass flakes are likely to peel off from the printed surface or the surface of the coating film. On the other hand, considering the applicability of ink or paint, the concentration of glass flakes is preferably in the above range.

The thickness of the coating film containing glass flakes is preferably 10 to 500 μm. 10 μm
If it is thinner, the water resistance will be insufficient. On the other hand, 500
If the thickness is thicker than μm, unevenness is likely to be formed on the surface of the coating film, and the directivity of reflected light may decrease.

When glass flakes are blended in the resin composition, the glass flake content is 5 to ensure that the glass flakes are present near the outer surface of the resin composition.
It is preferably 30% by weight.

By blending glass flakes in a packaging film for packaging products, it is possible to reduce detection omissions of the number of products in the manufacturing process.

Since these license plates, bar codes, package films and the like can be manufactured using known manufacturing methods and devices, the manufacturing cost is low. Further, in introducing these, since the infrared detector used in the conventional ITS or POS system can be used as it is, there is an advantage that the introduction cost is low. Therefore, according to the present invention, in the conventional system for recognizing an object by detecting infrared rays, it is possible to surely improve the recognition accuracy while suppressing the cost.

[0030]

EXAMPLES The present invention will be described in detail below with reference to examples. (Example 1) and (Comparative Example 1) Glass flakes coated with silver by an electroless plating method (RCFSX-5150PS 9023 manufactured by Nippon Sheet Glass Co., Ltd.)
Silver film thickness 100nm Average particle size 150μm Average thickness 5μ
m) was kneaded in a urethane clear paint so that the concentration was 12.3% by weight and the content rate in the total solid content was 40% by weight. The paint was applied to the surface by spraying so that the average film thickness was 100 μm. After confirming that the coating film was completely dried, the infrared reflectance of this license plate (Example 1) was measured according to JIS 3106. For comparison, a license plate of the same type without a coating film (Comparative Example 1)
The infrared reflectance was measured by the above means.
As a result, the license plate of Example 1 has wavelengths of 950 nm and 1,200 nm as compared with the license plate of Comparative Example 1.
In and, the reflectance was improved by about 30%. From this, it is understood that the use of the license plate of the present invention can improve the recognition accuracy of the characters and numbers in the system that recognizes an object by sensing infrared rays.

Example 2 Glass flakes that absorb infrared rays (manufactured by Nippon Sheet Glass Co., Ltd., average particle size: 150 μm, average thickness: 5 μm) were added to a urethane clear paint of the same type as in Example 1 at a concentration of 12.3% by weight and the total amount. Content of solid content 40% by weight
Kneaded so as to give an average film thickness of 1 by spraying on the entire surface of a license plate of the same type as in Example 1.
It was applied so as to be 00 μm. Then, by the same means as in Example 1, a paint containing glass flakes that reflect infrared rays was applied only to the letters and numbers.

After confirming that the paint is completely dried,
This license plate and the license plate of Example 1 were placed side by side on a black floor, and an infrared photograph was taken from 10 m above. When this photograph was shown to five sensory examiners, all the examiners obtained the evaluation that letters and numbers were clearly shown on the license plate of Example 2.

[0033]

Since the present invention is constructed as described above, it has the following effects. By using glass flakes with a smooth surface and a large specific surface area, infrared rays can be effectively reflected or absorbed, so that the recognition accuracy of the object can be improved without improving the conventional infrared ray-using device. Can be increased. Furthermore, it is possible to inexpensively provide a device for carrying out this method, and a system using these devices and methods.

Claims (11)

[Claims] 1. A system for recognizing an object by detecting infrared rays, wherein the object contains glass flakes to improve the recognition accuracy. 2. The glass flake has silver (A
g), titanium nitride (TiN), titanium dioxide (TiO₂), Oxidized Cova
Rut (Co0), iron oxide (Fe₂O₃), Chromium oxide (Cr₂O ₃), Oxidation
Indium (In₂O₃), Tin oxide (SnO₂), Zinc oxide (ZnO)
Or a thin film containing antimony oxide (SbO) as a main component
The method for improving the recognition accuracy according to claim 1, wherein 3. The glass flake contains, as composition components, 0.1 to 2% by weight of iron oxide (Fe ₂ O ₃ ) and 1 to 2% by weight of cerium (CeO ₂ ), and cobalt oxide. (CoO) is 0
~ 200 ppm and selenium (Se) 0 to 20 ppm, or nickel oxide (NiO) 100 to 1,000 pp
The method for enhancing recognition accuracy according to claim 1 or 2, wherein the method includes m. 4. The glass flakes have an average particle size of 10 to 10.
The method for enhancing recognition accuracy according to any one of claims 1 to 3, wherein the recognition accuracy is 4,000 µm and the average thickness is 0.1 to 20 µm. 5. A license plate in which glass flakes reflecting infrared rays are present in the letters or numbers. 6. A license plate in which glass flakes reflecting infrared rays are present in the letters or numbers and glass flakes absorbing infrared rays are present in the periphery thereof. 7. A bar code in which glass flakes reflecting infrared rays are present in the code part or in the interval thereof. 8. A bar code in which glass flakes reflecting infrared rays are present in either one of the code portions or their intervals, and glass flakes absorbing infrared rays are present in the other. 9. A package film containing glass flakes that reflect infrared light. 10. An intelligent transportation system using the method according to any one of claims 1 to 4. 11. A POS system using the method according to any one of claims 1 to 4.