JP2004048624A - Tag transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To process a plurality of tag information and process them nearly at the same time, in case that a transmittable range of a tag transmitter is limited in an area in which a seizure signal receiving coil inside of the tag transmitter can receive, and there are a plurality of tag transmitters in the receiving area of the receiver, enlarging a communication distance in which data communication of tag information is possible. <P>SOLUTION: Transmittable range of the tag transmitter is limited in the receivers area, while enlarging the communication distance by delivering a feeble radio wave or specific small power radio wave in a UHF band from the tag transmitter, by making receiving of a tag seizure signal in long wave length band as an opportunity. On the other hand, the transmission timing is that data transmission of tag information sent from each tag transmitter is made in time shifting, by a measure to randomly repeat transmission in a time multiplied a variable value stored inside of the tag by a random value of a random value generating part making the tag seizure signal as a clock. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tag system (RFID) for transmitting data of tag information (ID) stored in a tag transmitter in a tag transmitter to a receiving facility using radio frequency (RF).
[0002]
[Prior art]
FIG. 1 is a block diagram of a conventional tag transmitter, which comprises, for example, a start signal receiving coil 1, a parallel / serial converter 2, a data latch 3, an EEPROM 4, and a transmitter 5. Further, the tag system is used as an identification processing system for a mobile object, and is generally well known as being used in an ID management tag system for transmitting single data stored in advance at a short distance, a security system, and the like.
[0003]
Since the tag system as described above usually does not have the power of a battery or the like, the transmission power of the transmission unit 5 is extremely small, and the communication distance in which tag information data can be transmitted is limited to several cm to several tens cm.
Also, when there are a plurality of tag transmitters in the reception area of the receiver, since the plurality of tag transmitters transmit data, an interference condition occurs, and individual tag information cannot be processed. There was a problem that they could not be processed simultaneously.
[0004]
[Problems to be solved by the invention]
To summarize the problems of the prior art,
Assignment 1. A conventional tag system usually does not have the power of a battery or the like, so the transmission power of the transmission unit 5 is extremely small, and the communication distance for transmitting tag information data is limited to several cm to several tens cm. . In the method of always radiating a weak radio wave or a specific low-power radio wave to achieve the first problem and expanding the distance, there is a case where the radio wave can be received in a reception area of another receiver installed nearby. The problem is that it is necessary to limit the receiving area. 3. In a conventional tag system, when a plurality of tag transmitters exist in a reception area of a receiver, a plurality of tag transmitters transmit data, so that interference occurs and individual tag information cannot be processed. In a conventional tag system, when there are multiple tag transmitters in the reception area of the receiver, the multiple tag transmitters transmit data, resulting in interference, and multiple tag information cannot be processed almost simultaneously. is there. Therefore, the present invention has been made to solve the above-described problem, and the range in which the tag transmitter can transmit is determined by the activation signal receiving coil inside the tag transmitter while expanding the communication distance in which the tag information data can be transmitted. An object of the present invention is to limit the reception area to a receivable area and, when a plurality of tag transmitters exist in the reception area of the receiver, to process a plurality of tag information and to process the tag information almost simultaneously.
[0005]
[Means for Solving the Problems]
The present invention, while aiming to increase the communication distance of tag information data transmission from the tag transmitter, the range that can be transmitted by the tag transmitter is limited to the area that can be received by the activation signal receiving coil inside the tag transmitter, Since the communication distance is limited in the conventional method without a battery, the present invention has a battery, and the tag transmitter inside the tag transmitter receives a 100 KHz band tag activation signal transmitted from the activation signal transmission coil on the receiver side. At the same time, the above problem 1 is solved by transmitting a weak radio wave or a specific low-power radio wave in the UHF band from the tag transmitter to increase the communication distance over which the tag transmitter can transmit data.
When the tag transmitter transmits data only during the time when the tag transmitter signal of the 100 kHz band is received inside the tag transmitter, the tag transmitter of the 100 kHz band which is radiated into space as a radio wave through the coil coil antenna for transmitting the start signal. By appropriately setting the signal power and the radiation pattern, the above problem 2 is solved by limiting the reception area of the receiver,
On the other hand, the transmission timing from the tag transmitter is a time period obtained by multiplying the variable value stored in the EEPROM inside the tag transmitter and the random number value of the random number generator inside the tag transmitter using the tag start signal as a clock. By means of repeating the transmission at random, the data transmission of the tag information transmitted from each tag transmitter is shifted and transmitted, so that when there are multiple tag transmitters in the reception area of the receiver, Thus, the problems 3 and 4 can be solved by processing a plurality of pieces of tag information and processing them at substantially the same time.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 2 is a block diagram of a tag system showing one embodiment of the present invention. The tag transmitter 10, the starting signal transmitting coil antenna 11, the 100 KHz band starting signal transmitting unit 12, the UHF band receiving antenna 13, and the UHF band of the present invention. It comprises a receiver / data processing unit 14.
FIG. 3 is a block diagram of the tag transmitter 10 of the present invention. The activation signal reception coil 20, the clock generation unit 21, the M-sequence random number generation unit 22, the parallel / serial conversion unit 23, the UHF band transmission unit 24, the activation pulse generation and It comprises various timing generators 25, a data latch unit 26, a battery 27, and an EEPROM 28.
[0007]
Next, the operation of the tag system of the present invention will be described. The tag activation signal in the 100 KHz band generated by the 100 KHz activation signal transmission unit 12 is radiated to the space as radio waves via the activation signal transmission coil antenna 11. When the tag transmitter 10 of the present invention exists in this space, the radio wave radiated into the space enters the start signal receiving coil 20 in the tag transmitter 10 of the present invention, and the clock generator 21 generates a clock of about 100 KHz. create. When this clock is stabilized, the start pulse generation and various timing generators 25 set the internal gate signal 30 and generate a start pulse 31 upon the rise of the internal gate signal 30.
[0008]
Next, when a start pulse 31 generated by the start pulse generation and various timing generation sections 25 is generated, the data value to be transmitted from the tag transmitter 10 and stored in the EEPROM 28 in advance is stored in the data latch section 26. After that, the data value stored in the data latch unit 26 enters the parallel / serial conversion unit 23, and is sequentially transmitted by the UHF band transmission unit 24 by the shift register in the parallel / serial conversion unit 23, or the weak radio wave of the UHF band or a specific small signal. It is radiated to space as electric power radio waves. In the embodiment of the present invention, the communication distance can be increased to several meters.
[0009]
Next, the UHF band weak radio wave or the specific low-power radio wave transmitted from the tag transmitter 10 enters the UHF band reception antenna 13 and is demodulated as data by the UHF band receiver / data processing unit 14. The demodulated data is transferred to a higher-level system (for example, an aggregation system) via, for example, a LAN.
[0010]
On the other hand, the tag transmitter 10 multiplies the random number value generated by the M-sequence random number generation unit 22 by the variable value stored in the EEPROM 28 after the data transmission starts (or after the data transmission ends) ( After the transmission data transmission interval TP 35), the data value stored in the data latch unit 26 enters the parallel / serial conversion unit 23, and is sequentially shifted by the shift register in the parallel / serial conversion unit 23 into the UHF band by the UHF band transmission unit 24. Radiated into space again as a weak radio wave or a specific low-power radio wave. These series of operations are repeated while the internal gate signal 30 is set.
[0011]
When a plurality of tag transmitters exist in the reception area of the receiver, the random number value generated by the M-sequence random number generation unit 22 in each tag transmitter 10 and the variable value stored in the EEPROM 28 are used. Since the multiplied time (transmission data transmission interval TP35) is different, the data transmission timing of the tag information transmitted from each tag transmitter 10 is shifted. The UHF band receiver / data processing unit 14 is transmitted at a time interval obtained by multiplying the random number value generated by the M-sequence random number generation unit 22 of each tag transmitter 10 by a variable value stored in the EEPROM 28. Therefore, the individual pieces of received data can be sequentially processed by being received with deviations, so that it is possible to process a plurality of pieces of tag information almost simultaneously.
[0012]
The internal gate signal 30 of the tag transmitter 10 indicates that if the tag transmitter 10 cannot move to receive the tag activation signal in the 100 kHz band radiated from the activation signal transmission coil antenna 11 due to the movement of the tag transmitter 10, the tag transmitter 10 Stop sending data. Due to the above operation, the tag transmitter 10 transmits the data of the tag information only when the tag activation signal in the 100 KHz band is received, so that the 100 KHz radiated to the space as radio waves via the activation signal transmission coil antenna 11 is transmitted. By appropriately setting the power and the radiation pattern of the tag activation signal of the band, it is possible to limit the reception area of the receiver. Note that the battery 27 is consumed while the internal gate signal 30 is set in each element inside the tag transmitter 10, thereby suppressing consumption of the battery 27.
Further, in the embodiment of the present invention, the starting signal of the long wave band uses about 100 KHz, but other long wave band frequencies may be used as the starting signal.
FIG. 4 is a time chart illustrating the operation of the tag transmitter 10.
[0013]
【The invention's effect】
According to the present invention, when the tag transmitter receives a tag activation signal of about 100 kHz in the long wave band transmitted from the activation signal transmission coil on the receiver side, the tag transmitter transmits a weak radio wave in the UHF band. Alternatively, by transmitting a specific low-power radio wave, the range in which the tag transmitter can transmit can be limited to an operationally necessary area while expanding the communication distance that the tag transmitter can transmit.
However, in the conventional method, the distance from the starting signal transmitting coil antenna is limited to several cm to several tens of centimeters.Therefore, when the starting signal transmitting coil antenna is installed, a reinforcing bar or the like is placed directly under a concrete road surface, an iron bridge or other road surface. On a road surface that disturbs the radiation pattern of the radio wave from the start signal transmitting coil antenna, the influence of the radio wave radiation from the start signal transmitting coil antenna is imposed, so that the setting method of the start signal transmitting coil antenna is restricted.
In the present invention, it is possible to limit the range in which the tag transmitter can transmit to the area required for operation while expanding the communication distance that the tag transmitter can transmit. There is an advantage that the restriction can be eased in the method of installation such as hanging from the ceiling. Further, there is an advantage that the receiving section of the tag transmitter can be constituted by a simple resonance circuit.
On the other hand, the transmission timing from the tag transmitter is randomized by the time obtained by multiplying the variable value stored in the EEPROM inside the tag transmitter and the random number value of the random number generator inside the tag transmitter by using the tag activation signal as a clock. Means that repeats the transmission of the tag information, it is possible to transmit the tag information data transmitted from each tag transmitter at a different timing, and when there are multiple tag transmitters in the reception area of the receiver In, the receiver and the data processing unit can sequentially process the data by receiving the data from the individual tag transmitters shifted, so that it is possible to process a plurality of pieces of tag information almost simultaneously.
[Brief description of the drawings]
FIG. 1 is a block diagram of a conventional tag transmitter. FIG. 2 is a block diagram of a tag system of the present invention. FIG. 3 is a block diagram of a tag transmitter of the present invention. FIG. 4 is an operation time of the tag transmitter of the present invention. Chart diagram [Explanation of symbols]
1 is a starting signal receiving coil,
2 is a parallel / serial converter,
3 is a data latch unit,
4 is an EEPROM,
5 is a transmitting unit,
10 is a tag transmitter of the present invention,
11 is a starting signal transmitting coil antenna,
Reference numeral 12 denotes a 100 KHz band activation signal transmission unit,
13 is a UHF band receiving antenna,
14 is a UHF band receiver / data processing unit,
20 is a starting signal receiving coil,
21 is a clock generator,
22 is an M-sequence random number generator,
23 is a parallel / serial converter,
24 is a UHF band transmitter,
25 is a start pulse generation and various timing generation unit,
26 is a data latch unit,
27 is a battery,
28 is an EEPROM,
30 is an internal gate signal,
31 is a starting pulse,
32 is a transmission gate signal,
33 is a data read time TL,
34 is transmitting data,
35 is a transmission data transmission interval TP.

Claims (2)

A means for generating a weak radio wave or a specific low-power radio wave by receiving a start signal in the long wave band, and a variable value stored in a recording element inside the tag transmitter and a random number generating means inside the tag transmitter. A tag transmitter that repeats transmission randomly at a time obtained by multiplying a random number value inside the tag transmitter by an internal variable value. A means for generating a weak radio wave or a specific low-power radio wave by receiving a start signal in the long wave band, and a variable value stored in a recording element inside the tag transmitter and a random number generating means inside the tag transmitter. A transmission method in the tag transmitter, wherein the transmission is randomly repeated at a time obtained by multiplying a random number value inside the tag transmitter by an internal variable value.

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