JPH10171955A - Identification tag for traveling object and identification system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a system which identifies an individual traveling object by using an optical passive tag which reads identification information from a reflection intensity pattern which comes from an identification tag for a traveling object that is accompanied with moving and easily improving the directivity of light without any need to install a complicated device on the traveling object side. SOLUTION: A non-contact tag 10 on which identification information is written by carving diffraction grating on a near infrared reflection film that makes visible light permeate and reflects near infrared light is adhered on the inside of a vehicle within the operation range of a wiper of a windshield 31 of a vehicle 30 by a adhesive layer that makes visible light and near infrared light permeate. The tag 10 is irradiated with laser beams 23 from a near infrared laser 21, and identification information which is written on the tag 10 is discriminated from the intensity pattern of light that is received by a light receiving device 42 accompanying the movement of the vehicle 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an identification tag for a mobile object used for identifying an individual mobile object and an identification system using the identification tag for a mobile object.

[0002]

2. Description of the Related Art An identification tag on which identification information for identifying an individual vehicle is written is installed on a vehicle, and the identification information written on the identification tag is identified by an identification device installed at a plurality of positions. A system has been proposed in which an identification system is used to specify a passage route of each vehicle and the like, and traffic control is performed based on obtained information.

A conventional identification system will be described with reference to FIG. A microwave 52 including an access signal is transmitted from a microwave transmitting / receiving antenna 51. In response to the access signal, a microwave 54 including identification information is transmitted from a microwave tag 53 installed in the vehicle 30, the microwave 54 is received by the microwave transmitting / receiving antenna 51, and identification is performed based on the received microwave 54. The device 55 has determined the identification information.

[0004]

The microwave tag needs an antenna and a power supply for receiving and transmitting the microwave, and has a problem that the configuration of the device installed in the vehicle is complicated. In addition, it is necessary to transmit an access signal to one specific vehicle in order to individually recognize the vehicles. Therefore, it is necessary to increase the directivity of the microwave transmitted from the microwave transmitting / receiving antenna, but there is a problem that the structure of the microwave transmitting / receiving antenna becomes complicated in order to increase the directivity.

An object of the present invention is to provide an identification tag and an identification system for a mobile object which can simplify a device attached to the mobile object and a device for reading identification information.

[0006]

SUMMARY OF THE INVENTION A moving object identification tag and an identification system according to the present invention are configured as described below to solve the above-mentioned problems. (1) A moving object identification tag of the present invention (claim 1) is a moving object identification tag in which identification information for recognizing each moving object is written and attached to the moving object. A near-infrared reflective film that reflects the region light, and a diffraction grating that is formed in a predetermined region of the near-infrared reflective film and that changes the reflection angle of the near-infrared region light. Is written therein.

[0007] In the identification tag for a moving object according to (1), wherein the near-infrared reflecting film transmits visible light, and the visible light and the near-infrared light are attached. It is installed inside the glass and in the operating range of the means for removing stains on the glass by using an adhesive layer that transmits a region light.

[0008] The moving object identification tag is attached to a moving object such as a vehicle, a ship, an aircraft, and luggage. The infrared reflection film is made of a dielectric multilayer film or the like. (2) An identification system of the present invention (Claim 3) is a means for irradiating near-infrared region light to the moving object identification tag according to claim 1, which is attached to the moving object; Detecting means for detecting the reflected light intensity of the moving object, and an identification device for determining identification information unique to the moving object identification tag from the intensity pattern detected by the detecting means with the movement of the moving object. It is characterized by becoming.

The moving object identification tag and the identification system of the present invention have the following functions and effects by the above configuration. Diffraction gratings with different lattice constants and arrangement intervals are formed on the near-infrared reflective film of the moving object identification tag, and identification information unique to each moving object identification tag is written by combining the diffraction gratings. Then, the moving identification tag for the moving object is irradiated with near-infrared light, and the identification information is determined by the identification device from the intensity pattern of the reflected light from the identification tag for the moving object. Therefore, the moving object does not require a complicated electronic circuit or power supply in the moving object.

The wavelength of near-infrared light is 1/10 to 1/1000 of that of electromagnetic waves such as microwaves, and the directivity can be easily increased by combining a laser and a lens. There is no need to use a complicated antenna as used in the conventional identification system, and the device can be simplified.

When the mobile object identification tag is installed on a vehicle or a ship, the wiper or the like is installed in an operating range of a wiper or the like for clearing the field of view inside the windshield, so that dirt that hinders light transmission is removed by the wiper. And become more resistant to dirt. Furthermore, the near-infrared reflective film and the adhesive layer for bonding the near-infrared reflective film to glass transmit visible light, and thus do not obstruct the driver's view.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a non-contact tag according to one embodiment of the present invention. Here, FIG.
FIG. 1A is a plan view of a non-contact tag, and FIG. 1B is a cross-sectional view.

A non-contact tag (moving object identification tag) 10 includes a sheet 11, a near-infrared reflective film 12, and an adhesive layer 14. The sheet 11 is made of visible light (wavelength: about 350 nm to 7).
The sheet 11 transmits visible light and near-infrared light (wavelength: 70 nm).
A near-infrared reflective film 12 that reflects light from 0 nm to 2 μm) is formed. The sheet 11 is made of, for example, polycarbonate, and the near-infrared reflecting film 12 is made of, for example, a dielectric multilayer film. The near-infrared reflective film 12 can be made of a material other than the dielectric multilayer film.

In a predetermined region of the near-infrared reflective film 12, a diffraction grating 13 (13a, b, c) having a different lattice constant and having a lattice constant of about the wavelength of a laser beam, which will be described later, is engraved. The diffraction grating 13 is formed by using a general fine pattern forming method such as a photolithography method or a laser scribing method.

The adhesive layer 14 is formed of the near-infrared reflective film 12
It is provided above and transmits visible light and near-infrared light. Adhesive layer 1
Reference numeral 4 is used for attaching to a windshield described later, and desirably has a refractive index close to the refractive index of an object to be attached. As close as the refractive index of the windshield of the vehicle,
For example, there is EPO-TEK301-2 (manufactured by Epoxy Technology).

A vehicle identification system using the non-contact tag 10 will be described with reference to FIGS. A near-infrared laser 21 for irradiating the non-contact tag 10 with near-infrared light is provided. As the near-infrared laser 21, for example, 1.55
A semiconductor laser emitting a wavelength in the μm band is used.
A lens 22 for irradiating a laser beam 23 from the near-infrared laser 21 in a range not exceeding the vehicle width is provided.

The non-contact tag 10 is adhered to the inside of a windshield 31 of the vehicle 30 using an adhesive layer within an operating range of a wiper 32 provided on the vehicle to improve the driver's visibility. Since the stain on the outside of the windshield 31 is removed by the wiper 32, the stain on the transmission area of the laser beam 23 does not matter. In addition, the non-contact tag 10
Has the property of reflecting invisible near-infrared light and transmitting visible light, and therefore does not obstruct the driver's view of the vehicle 30.

The diffracted reflected light 2 from the non-contact tag 10
4 (24a, b, c) is provided with a slit 41. A light receiver 42 for measuring the intensity of light passing through the slit 41 is provided. An identification device 43 that determines the identification information written on the non-contact tag 10 from the measured light intensity pattern is provided.

FIG. 2 shows only the diffracted reflected light 24 reflected by the diffraction grating of the non-contact tag 10. The operation of the present embodiment will be described. The vehicle 30 is irradiated with laser light 23 from the near-infrared laser 21 via the lens 22. The laser light 23 is reflected by the near-infrared reflective film of the non-contact tag 10. Then, the diffracted reflected light 24 enters the light receiver 42 via the slit 41. The light receiver 42 converts the incident light intensity into an electric signal and outputs the electric signal to the identification device 43.

When the light is reflected by the non-contact tag 10, the reflection angle is changed by the diffraction grating. The grating constants of the diffraction gratings provided in the non-contact tag 10 are different,
Diffracted reflected light 24a, which is diffracted and reflected by each diffraction grating,
The reflection angles of b and c are also different. Therefore, vehicle 3
With the movement of 0, the diffracted reflected lights 24a, b, and c sequentially enter the light receiver 42 via the slit 41. Therefore, the light intensity received by the light receiver 42 changes, and the identification information written in the non-contact tag 10 is determined by the identification device 43 from the obtained light intensity pattern.

The identification information unique to each non-contact tag is written in the non-contact tag 10 by changing the lattice constant and the number of the diffraction gratings or by arranging the types of the diffraction gratings. be able to.

According to this embodiment, the reflection angle of near-infrared region light reflected by the diffraction grating of the non-contact tag is changed,
The identification information can be read from the intensity pattern of the reflected light that changes with the movement of the vehicle.

Further, by installing the non-contact tag inside the windshield within the operating range of the wiper, it is possible to suppress a change in light intensity due to dirt on the glass.

Further, since the sheet, the near-infrared reflective film, and the adhesive layer constituting the non-contact tag transmit light in the visible light range, they do not obstruct the driver's view. The present invention is not limited to the above embodiment. For example, a non-contact tag is not limited to identifying a vehicle, but can be used to identify a moving object such as a ship, an aircraft, or luggage.
When used for identifying luggage, the infrared reflection film may not have the property of transmitting visible light. The present invention is not limited to the above embodiment, and can be implemented in various modifications without departing from the spirit of the present invention.

[0025]

As described above, according to the present invention, by using an optical passive tag for reading out identification information from a reflection intensity pattern from a moving object identification tag accompanying movement, a complicated device is provided on the moving object side. It is not necessary to install a tag, and the directivity of light can be easily increased, so that the identification tag and the identification system can be easily simplified.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a non-contact tag according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an identification system using the non-contact tag of FIG. 1;

FIG. 3 is a schematic view showing the installation of a non-contact tag.

FIG. 4 is a schematic diagram showing a configuration of a conventional identification system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 non-contact tag (moving object type tag) 11 sheet 12 near-infrared reflective film 13 diffraction grating 14 adhesive layer 21 near-infrared laser 22 lens 23 laser beam 24 diffracted reflected light 30 vehicle (moving object) 31 windshield 32 wiper 41 slit 42 light receiver 43 identification device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G08G 1/01 G08G 1/13 1/13 G09F 3/00 M G09F 3/00 G06K 19/00 CE

Claims (3)

[Claims] An identification tag for a moving body, on which identification information for recognizing an individual moving body is written and attached to the moving body, comprising: a near-infrared reflective film for reflecting light in a near-infrared region; A diffraction grating formed in a predetermined region of the near-infrared reflective film to change a reflection angle of near-infrared region light, wherein unique identification information is written by a combination of the diffraction gratings. Mobile body identification tag. 2. The identification tag for a moving object according to claim 1, wherein the near-infrared reflective film transmits visible light, and transmits the visible light and the near-infrared light. Using an adhesive layer that transmits the area light, the inside of the glass,
A moving object identification tag, which is installed in an operating range of a means for removing stains on the glass. 3. A means for irradiating near-infrared region light to the moving object identification tag according to claim 1, which is attached to the moving body, and a detecting means for detecting the intensity of light reflected from said moving body. An identification device for identifying identification information unique to the mobile object identification tag from an intensity pattern detected by the detection means in accordance with the movement of the mobile object.