JP2008257489A - Non-contact ic tag system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact IC tag system for supplying a power from a reader/writer side, and for performing stable data signal transmission, and for performing spot-like transmission which does not interfere with each other even when there are several data to be written in an IC tag. <P>SOLUTION: In this non-contact IC tag system 10 equipped with a reader/writer 11 and an IC tag 12, the reader/writer 11 side is provided with a data transmission part 14 for transmitting a predetermined emission pattern with visible rays of light L, and the IC tag 12 side is provided with a data reception part 24 for receiving the emission pattern, wherein data are transmitted through the visible rays of light L, and a power is supplied through a carrier wave R to be transmitted from the reader/writer 11 side to the IC tag 12 side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a non-contact IC tag system using visible light for data signal transmission.

  In recent years, non-contact IC tags that can check and manage various information (data) such as serial numbers and date of manufacture of products or products by transmitting and receiving via radio waves (carrier waves) have been widely used. It has come to be used. As shown in FIG. 4, the basic configuration using this IC tag is made up of a sheet-like IC tag 3 attached to a product and the like, and a reader / writer 2 that exchanges data with this IC tag 3 via a carrier wave R. Become.

  The IC tag 3 includes an antenna 4 for receiving data carried on a carrier wave R, a memory unit 5 for storing the data, a control circuit 6 for controlling input / output of data, and the like. . The reader / writer 2 includes a main body 7 having a reading unit for data to be transmitted to the IC tag 3, a power supply unit, and the like, and data written to the IC tag 3 from the main body 7 via the carrier wave R. An antenna 8 for supplying transmission and power is provided.

  Since the IC tag 3 having the above-described structure is a passive type that does not have a power supply unit and supplies power from the reader / writer 2 via the carrier wave R, data and power can be transmitted with a single carrier wave. This is done via R. Thus, when transmitting data and electric power on the carrier wave R, the carrier wave R is subjected to processing such as predetermined modulation and encoding.

  FIG. 5 shows an example of a product management line using the IC tag 3. In this example, an IC tag 3 is attached to each product 9b flowing on the belt conveyor 9a, and a plurality of reader / writers 2 having antennas 8 are arranged at predetermined intervals below the belt conveyor 9a. It is configured. Different data is stored in each of the reader / writers 2, and such data is sequentially written in the IC tag 3 in the process of passing the product 9 b flowing on the belt conveyor 9 a. In such a system, when the reader / writer 2 is arranged adjacent to each other, a superposition region M where carrier waves R output from the respective antennas 8 overlap each other is generated, and this superposition region M is defined as the product 9b. May pass, incorrect data may be written to the IC tag 3.

In order to avoid such interference between the carrier waves R and to perform an accurate data writing operation, it is necessary to accurately correspond the antenna 8 provided on the reader / writer 2 side to the IC tag 3. For this reason, Patent Document 1 discloses a configuration example in which a light source for projecting spot light is provided on the reader / writer, and data is written at the timing when the spot light is projected onto an IC tag.
JP 2006-11839 A

  In the passive type IC tag, as described above, in order to transmit data and power on a single carrier wave R, the process for setting and adjusting the modulation degree on the carrier wave R is performed. Becomes complicated. In addition, processing such as encoding and band limitation for digitally encoding and transmitting data is required.

  Regarding the processing applied to the carrier wave R, if the degree of modulation is too high, power supply is insufficient during data transmission. Conversely, if the degree of modulation is too low, a data transmission error occurs. There is a problem that it is not easy to set or maintain.

  The carrier wave R is easily affected by environmental changes caused by electromagnetic waves emitted from surrounding electrical products, mobile phones, etc., weather phenomena, and the like. For this reason, there is a problem that transmission / reception error, transmission delay, etc. are likely to occur due to the occurrence of noise, especially during data transmission, and the reliability is insufficient.

  Further, as shown in FIG. 5, when writing different data from a plurality of readers / writers 2 to the IC tag 3, if the reader / writers 2 are arranged adjacent to each other, transmission using the carrier wave R is not possible. Interact with each other. For this reason, even if the direction of the antenna is adjusted by the spot light as shown in Patent Document 1, it is difficult to accurately aim the IC tag with the carrier wave R having a wide propagation range. There was a problem that data signals could not be transmitted.

  Therefore, an object of the present invention is to enable stable transmission of data signals while supplying power from the reader / writer side, and to perform spot-like transmission that does not interfere with each other even when there are a plurality of data to be written to the IC tag. It is to provide a non-contact IC tag system capable of performing the above.

  In order to solve the above problems, a non-contact IC tag system of the present invention is a non-contact IC tag system including a reader / writer and an IC tag, and transmits a predetermined light emission pattern by visible light to the reader / writer side. And a data receiving unit that receives the light emission pattern on the IC tag side, thereby transmitting data via the visible light and an IC tag via a carrier wave transmitted from the reader / writer side. Power is supplied to the side.

  According to the non-contact IC tag system according to the present invention, since data consisting of various types of information is transmitted through a visible light different from a carrier wave, stable high quality without being affected by an external environment or the like. Data can be transmitted. In addition, by separating the data transmission from the conventional carrier wave, the power transmission efficiency by the carrier wave is also improved.

  In addition, since visible light is used for the transmission of the data, the transmission range can be limited to the angle and distance at which the light reaches, so that it is possible to write data in a spot-limited range. Thus, even when a plurality of readers / writers are arranged adjacent to each other, necessary data can be accurately written without interference or interference between the plurality of data.

  Embodiments of a non-contact IC tag system according to the present invention will be described below in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a contactless IC tag system 10 of the present invention includes a reader / writer 11 and an IC that receives data and power via visible light L and radio wave (carrier wave) R emitted from the reader / writer 11. It consists of a tag 12.

  As shown in FIG. 2A, the reader / writer 11 includes a main body 13 that stores data and power to be transmitted to the IC tag 12, and a data transmitter 14 that transmits the data from the main body 13. And a power transmission unit 15 for transmitting power.

  The data transmission unit 14 includes a visible light pattern conversion unit 16 that converts writing information (data signal) stored in the main body unit 13 into a light emission pattern by visible light L, and the light emission pattern is directed outward. And a light emitting unit 17 for irradiation.

  The light emitting unit 17 is a spotlight that uses a light emitting diode or a laser diode as a light source, and is housed in the same casing as the main body unit 13 or arranged separately from the casing so as to be variable in a predetermined irradiation direction. The The light-emitting diodes are generally divided into visible light and infrared light, but those of visible light type used for lamps indicating the operating state of various devices, light sources for display boards, and the like are used. . In particular, a white LED or the like among the visible light type light-emitting diodes is suitable for the system configuration of the present invention because it has high luminance so as to be used for lighting equipment and the like. Such a light-emitting diode has a very high switching speed and excellent durability compared to other lighting devices, so that high-speed ON-OFF repeated operation necessary for communication using visible light is possible. is there. The infrared light-emitting diodes are mainly used for communication applications such as IrDA and sensor applications such as position detection, but can also be used in place of the visible light-type light-emitting diodes. .

  The visible light L emitted from the light emitting unit 17 is a light ray visible to the human eye having a wavelength of 380 to 770 millimicrons. In this visible light, there is a light emission pattern by high-speed blinking that cannot be recognized by human eyes, and a data signal composed of predetermined information is created by a combination of the light emission patterns.

  Further, when the light emitting unit 17 is provided separately from the reader / writer 11, as shown in FIG. 1, the light emitting unit 17 is provided on the light collector 18 having a reflective surface surrounding the periphery of the substrate on which the light emitting diode is mounted. It is accommodated and connected via a cable 19. Further, a stand portion or a clip can be provided so that the light collector 18 can be easily arranged or attached.

  The power transmission unit 15 generates a carrier wave R for supplying power to the IC tag 12 and amplifies the carrier wave R to a predetermined output, and a transmission unit for releasing the amplified carrier wave R into the air An antenna 22 is provided. As an example, the transmitting antenna 22 transmits a 13.56 MHz carrier wave R at 100 mW. However, since the amount of power varies depending on the required communication distance with the IC tag, the output is adjusted as much as possible within the regulations of the Radio Law. In addition, other frequencies (2.45 GHz / specific low power) can be used to supply power, but it is necessary to design the transmitter within a standard based on the Radio Law.

  The IC tag 12 is configured based on a thin sheet-like base material, and includes a data receiving unit 24, a power receiving unit 25, a control circuit 28, and a memory unit 29 as shown in FIG. Yes.

  The data receiving unit 24 detects a light emission pattern by the visible light L emitted from the light emitting unit 17 on the reader / writer 11 side, and converts the light emission pattern detected by the light receiving unit 27 into a digital data signal. And a data conversion unit 26 for conversion. The light receiving unit 27 includes a photodiode or a photo IC that includes a driver circuit in addition to the photodiode. The photodiode has a characteristic of converting received light into a current. Therefore, in this system configuration, the light data transmitted from the light emitting unit 17 is received, and the received light data is sent to the data conversion unit 26 of the IC tag 12 as it is. The data conversion unit 26 amplifies the data of the blinking period sent from the transmission unit by the photodiode and converts it into a digital signal. Further, in order to efficiently receive the visible light L emitted from the light emitting diode, the photodiode is light-shielded except for the light receiving surface, and is mounted on the surface so as to be directed outward from the end of the mounting substrate. Is done.

  The power receiving unit 25 includes a receiving antenna 32 for receiving a carrier wave R emitted from a transmitting antenna 22 on the reader / writer 11 side, and a carrier wave R captured via the receiving antenna 32. And a power conversion unit 31 that performs power conversion. The power converter 31 converts the carrier wave R received via the receiving antenna 32 into power for driving an IC tag. The carrier R having a frequency of 13.56 MHz is generally widely used, but a 900 MHz carrier or microwave (2.45 GHz) may be used.

  In this way, by detecting the carrier wave R transmitted from the reader / writer 11 with the receiving antenna 32 in the IC tag 12, power is generated using the induced electromotive force, and the control circuit 28 is thereby used. A clock signal is generated as a unit of time for executing an instruction via the. On the other hand, various information based on the data signal is written in the memory unit 29 by the light emission pattern by the visible light L emitted from the light emitting unit 17 of the reader / writer 11.

  Next, an application example using the non-contact IC tag system 10 will be described with reference to FIG. This application example is a system for sequentially writing information such as a serial number, date of manufacture, contents, etc. to an object 42 such as a product or a product that sequentially flows on the belt conveyor 41 and managing this information. A configuration example is shown. In the plurality of reader / writers 11 in this system, the light emitting units 17 are connected and arranged via cables 19. The main body 13 having a storage unit for data to be written to the IC tag 12 attached to the object 42 and a power supply unit are arranged together below the belt conveyor 41, and each light emitting unit 17 is connected to the IC tag 12. It is arranged in accordance with the passage interval of the object 42 marked with. The light emitting unit 17 is a spotlight using a light emitting diode as a light source, and is configured to have a single directivity by surrounding the light emitting diode with a cylindrical light collector 18. In this system, the light emitting unit 17 and the main body unit 13 are configured as a pair. However, the main body unit 13 has a single configuration, and a power supply unit common to the reader / writer; A switchable data transmission unit can be provided corresponding to each light emitting unit.

  As in the application example described above, the distance between the reader / writer 11 on the data transmission side and the IC tag 12 attached to the object 42 on the data reception side is relatively narrow, so that it is visible in the transmission of data signals within a limited range. Since the light L is used, only necessary information can be efficiently transmitted without being affected by an external electromagnetic field phenomenon or various noises. In particular, when different information is added to a single IC tag 12 from a plurality of readers / writers 11, the information does not interfere with each other. Further, since the light emitting unit 17 is independent of the reader / writer 11 and the irradiation direction of the visible light L can be changed, the position and direction of the object 42 to which the IC tag 12 on the information writing side is attached, or It becomes possible to adapt to the moving direction.

  The non-contact IC tag system 10 in the above application example is configured to sequentially write various information added to the object 42 such as a product while flowing on the belt conveyor 41. The present invention is not limited to the system, and can be applied to a management system for products and the like in a predetermined range such as a production line or a distribution line.

  As described above, in the contactless IC tag system according to the present invention, power transmission is performed using a conventional carrier wave, and data transmission including various kinds of information is separated and performed by visible light. Transmission and data transmission can be performed stably and accurately. Further, since the data transmission uses visible light as a medium, a data transmission error can be prevented by accurately determining the data writing position with respect to the IC tag.

1 is a schematic configuration diagram of a non-contact IC tag system according to the present invention. It is a system block diagram of the non-contact IC tag system. It is explanatory drawing which shows the application example of the merchandise management using the said non-contact IC tag system. It is a schematic block diagram of the conventional non-contact IC tag system. It is explanatory drawing which shows the application example of the merchandise management comprised using the conventional non-contact IC tag system.

Explanation of symbols

L Visible light R Carrier wave (Radio wave)
DESCRIPTION OF SYMBOLS 10 Non-contact IC tag system 11 Reader / writer 12 IC tag 13 Main part 14 Data transmission part 15 Power transmission part 16 Visible light pattern conversion part 17 Light emission part 18 Condensing body 19 Cable 21 Power modulation part 22 Antenna 24 Data reception part 25 Power receiving unit 26 Data converting unit 27 Light receiving unit 28 Control circuit 29 Memory unit 31 Power converting unit 32 Antenna 41 Belt conveyor 42 Object

Claims (5)

In a non-contact IC tag system including a reader / writer and an IC tag,
By providing a data transmission unit for transmitting a predetermined light emission pattern by visible light on the reader / writer side and a data reception unit for receiving the light emission pattern on the IC tag side, data is transmitted via the visible light. A non-contact IC tag system which supplies power to the IC tag side via a carrier wave transmitted from the reader / writer side. The non-contact IC according to claim 1, wherein the data transmission unit includes a visible light pattern conversion unit that converts data to be written on the IC tag side into the light emission pattern, and a light emission unit that irradiates the light emission pattern toward the outside. Tag system. The non-contact according to claim 1, wherein the data receiving unit includes a light receiving unit that detects the light emission pattern emitted from the light emitting unit, and a data conversion unit that converts the light emission pattern detected by the light receiving unit into data. IC tag system. The non-contact IC tag system according to claim 2, wherein the light emitting unit is configured by a light emitting diode or a laser diode. The non-contact IC tag system according to claim 3, wherein the light receiving unit is configured by a photodiode or a photo IC.

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