JPH01280274A - Response method of transponder in object identification device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] In order to identify objects conveyed by a belt conveyor or the like, an interrogator that emits radio waves to ask questions, and an interrogator that receives the radio waves and is activated to respond to the questions from the interrogator. Regarding the response method of the transponders in the object identification device to prevent interference when multiple transponders are activated at the same time in an object identification device consisting of a transponder, an interrogator can read information responded by multiple transponders. The interrogator is brought into the communicable range of the radio waves transmitted by the interrogator, generates a carrier wave when receiving the radio waves, modulates the carrier wave with preset information, and sends it to the antenna. In a transponder that responds to a question from the interrogator, a delay means is provided for delaying the time from when the interrogator receives the radio wave to when the carrier wave is generated by a preset time; When a plurality of transponders are brought into the communication range of the radio waves transmitted by the transponder, the plurality of transponders may contact the interrogator at different times depending on the time set in the delay means. Configure it to respond.

[Industrial application field]

In order to identify objects conveyed by a belt conveyor or the like, the present invention is an object identification device comprising an interrogator that emits radio waves to interrogate the object, and a transponder that receives the radio waves and is activated to respond to the interrogator's questions. In recent years, as user needs have diversified,
For example, in the manufacturing industry, which is forced to change its production format from mass production of a small number of products to production of a large number of products in small quantities, there is a need for technology to identify individual products during the manufacturing process.

For example, if multiple products are transported on a belt conveyor and the parts added to each product are different, the parts that need to be prepared in the subsequent process will be different, so it is necessary to identify the products to be transported on the belt conveyor in advance. It is necessary to have each department prepare parts necessary for post-processing.

For this purpose, an object identification device is used that makes it possible to collect index information such as numbers necessary to identify products by interrogating the products on the conveyor belt with an interrogator and having a responder respond. However, since the interrogator is fixed and the transponder moves with the product, the interrogator emits radio waves to activate the transponder and make it report the index information, but multiple transponders simultaneously It is necessary that there is no inconvenience when activated.

[Conventional technology]

FIG. 3 is a block diagram illustrating the conventional technology.

When the computer system 1 is notified by the detection signal of the sensor 8 that the pallet 5 on the belt conveyor 7 has reached the position where the interrogator 2 should be activated, it sends an activation signal to the interrogator 2 and the antenna 3 Send out radio waves. This radio wave can communicate within a space similar to an inflated balloon, and is called LOBE9. And this LOB
The maximum width X of E9 is, for example, approximately 1 m.

The transponder 4 is, for example, an IC card attached to the pallet 5, and when it receives the radio waves sent out by the interrogator 2, it changes from a standby state to reduce power consumption to a state in which it responds to the question from the interrogator 2. Shifts to the active state, generates a carrier wave, modulates this carrier wave with information described below, sends it to the antenna, and sends it to the antenna, which is set in advance.
The operator answers the interrogator 2 with information identifying the product 6 that has been loaded and transported.

The interrogator 2 receives and demodulates the radio waves sent from the antenna of the transponder 4, extracts the information sent by the transponder, and notifies the computer system 1 of the information. Therefore, the computer system 1 can recognize the type of product 6 that has been delivered, and can instruct, for example, to arrange parts and the like required in the post-processing process.

FIG. 4 is a block diagram illustrating an example of the responder 4. As shown in FIG.

The radio waves sent out by the interrogator 2 are received by the antenna 10, selected by the demultiplexer 11 that separates the received radio waves sent out by the interrogator 2 from the carrier waves sent out by the transponder 4, and sent to the demodulator 1.
2 and demodulated by a demodulator 12. The signal demodulated by the demodulator 12 is waveform-shaped in the activation signal generation circuit 13 and sent out as a signal for switching the operation mode of the data processing circuit 14.

That is, when the activation signal generation circuit 13 does not receive the radio waves sent by the interrogator 2, it sends a low level signal to the 5TBY terminal of the data processing circuit 14, and the interrogator 2 sends the radio waves to the demodulator. 12 sends a signal, it sends a high level signal to the 5TBY terminal of the data processing circuit 14, and after sending a low level signal for a certain period of time to the RES terminal of the data processing circuit 14, it sends a high level signal. do.

The data processing circuit 14 includes a processor 17, a RAM 18, and an R
Consists of OM19, port 20, etc., processor 17
operates by reading the program stored in the ROM 19, and when the 5TBY terminal becomes low level, it enters standby mode, stops the clock, etc., reduces the current consumption of the data processing circuit 14 to a few μA, and transmits the carrier wave through the port 20. The operation of the generator 16 is stopped. However, RAM18
is supplied with current and retains its stored contents.

When the 5TBY terminal becomes high level, the processor 17 enters the active mode and causes the clock oscillation circuit to oscillate, but while the RES terminal is at low level, it waits for the clock oscillation frequency to stabilize, and waits for the clock oscillation frequency to stabilize after a certain period of time. R.E.
When the S terminal becomes high level, the processor 17 activates each part in the data processing circuit 14, activates the carrier wave generator 16 via the port 20 to send a carrier wave to the modulator 15, and also outputs the data stored in advance from the RAM 18. Additionally, information such as a number identifying the product is read out and sent to the modulator 15 via the port 20.

The modulator 15 modulates the carrier wave sent out by the carrier wave generator 16 with the information, and sends it out to the antenna 10 via the demultiplexer 11.

As described above, the reason why the responder 4 switches the data processing circuit 14 and the carrier wave generator 16, which consume large amounts of power, to the standby state or the active state is when the pallet 5 or the like moving on the belt conveyor 7 This is because since the interrogator 2 is installed, the power is supplied by a battery or the like, and it is necessary to minimize the power consumption except for the time to respond to the interrogator 2.

[Problem to be solved by the invention]

FIG. 5 is a diagram explaining the problem.

As explained in FIG. 3, when the conventional transponder 4 receives the radio waves transmitted by the interrogator 2, the data processing circuit 14 operates in the active mode due to reception of the radio waves, and transmits response information to the interrogator 2. Send.

Therefore, as shown in FIG. 5, since the width of the pallets 5 and 5' placed on the belt conveyor 7 is small and the distance between them is narrow, the sensor 8 detects the pallet 5, and the computer system 1 activates the interrogator 2. When transmitting radio waves from the antenna 3, within the communicable space of the transmitted radio waves, that is, L
If transponders 4 and 4'' simultaneously exist within the width X of OBE 9, transponders 4 and 4'' respond simultaneously to the radio waves sent by interrogator 2.

In this case, the frequencies of the radio waves transmitted by the transponders 4 and 4 are the same, and the predetermined information is transmitted at the same time.
There is a problem in that the interrogator 2 cannot read the information sent by the transponders 4 and 4' due to interference.

In view of these problems, the present invention has been developed so that the transponders 4 and 4° respond to the radio waves sent out by the interrogator 2, and the data processing circuit 14
By setting a difference in the time when the transponders go into active mode and having the remaining transponders respond after one transponder completes the response, the radio waves sent by each transponder are prevented from being superimposed, and the interrogator 2 The purpose of the transponder is to be able to read the information sent by each of a plurality of transponders.

[Means to solve the problem]

FIG. 1 is a block diagram of the principle of the present invention.

The same reference numerals as in FIG. 4 indicate the same functions. Radio waves transmitted by the interrogator are received by an antenna 10, selected by a branching filter 11, and demodulated by a demodulator 12. The signal demodulated by the demodulator 12 undergoes waveform shaping in the activation signal generation circuit 13 and is sent to the data processing circuit 22 and the delay means 21.

When the activation signal generation circuit 13 does not receive the radio waves sent by the interrogator, it sends a low-level signal to the 5TBY terminal of the data processing circuit 22 via the delay means 21, and the interrogator sends the radio waves and demodulates them. When the device 12 sends out a signal, it sends out a high level signal to the delay means 21 while keeping the RES terminal of the data processing circuit 22 at a low level. The delay means 21 delays this high-level signal by a preset time and sends it to the 5TBY terminal of the data processing circuit 22.

When the delay means 21 sends a high-level signal to the 5TBY terminal of the data processing circuit 22, the activation signal generation circuit 13 sets the RES terminal of the data processing circuit 22 to a high level after a certain period of time has elapsed. When the 5TBY terminal becomes high level and the RES terminal also becomes high level, the data processing circuit 22 activates the carrier wave generator 16 to send the carrier wave to the modulator 15, and also sends information to the modulator 15. . Therefore, the modulator 15 modulates the carrier wave sent out by the carrier wave generator 16 with this information, and sends it out to the antenna 10 via the demultiplexer 11.

When the data processing circuit 22 finishes sending out the preset information, it stops the carrier wave generator 16 and stops the carrier wave being sent to the modulator 15. Then, when the interrogator stops transmitting radio waves, or the transponder moves out of the communicable range of the radio waves transmitted by the interrogator, and the delay means 21 again transmits a low-level signal to the 5TBY terminal, the standby state is entered. .

[Effect]

By configuring as described above, the transponder receives the radio waves sent out by the interrogator, generates a carrier wave after a preset time delay in the delay means 21, and modulates this carrier wave to respond. By setting the delay means 21 of each transponder to a different time, it is possible to prevent multiple transponders from simultaneously responding to the radio waves sent by the interrogator, thereby reducing interference. can be prevented.

〔Example〕

FIG. 2 is a block diagram of a circuit showing one embodiment of the present invention.

The same reference numerals as in FIG. 4 indicate the same functions. Radio waves transmitted by the interrogator are received by an antenna 10, selected by a branching filter 11, and demodulated by a demodulator 12. The signal demodulated by the demodulator 12 undergoes waveform shaping in the activation signal generation circuit 13 and is sent to the data processing circuit 22 and the time constant circuit 23.

The activation signal generation circuit 13 sends a low-level signal to the 5TBY terminal of the data processing circuit 22 via the time constant circuit 23 when the radio waves sent by the interrogator are not received. When the demodulator 12 sends out a signal, it sends out a high level signal to the time constant circuit 23 while keeping the RES terminal of the data processing circuit 22 at a low level. The time constant circuit 23 delays this high-level signal by a preset time to generate 5 TBY of the data processing circuit 22.
Send to terminal.

When the 5TBY terminal becomes high level, the processor 17 of the data processing circuit 22 enters the active mode and causes the clock oscillation circuit to transmit, but while the RES terminal is at low level, it waits for the clock oscillation frequency to stabilize.

When the time constant circuit 23 sends a high-level signal to the 5TBY terminal of the data processing circuit 22, the activation signal generation circuit 13 activates the RES of the data processing circuit 22 after a certain period of time has elapsed.
Set the terminal to high level. When the 5TBY terminal becomes high level and the RES terminal also becomes high level, the processor 17 of the data processing circuit 22 activates each part in the data processing circuit 22, and then reads out the program from the ROM 19.
It operates based on the instruction, starts the carrier wave generator 1G via the boat 20, sends out the carrier wave to the modulator 15, reads out pre-stored information for distinguishing products from the RAM 18, and outputs the carrier wave via the boat 20. The signal is sent to the modulator 15.

Therefore, the modulator 15 modulates the carrier wave sent out by the carrier wave generator 16 with this information, and sends it out to the antenna 10 via the demultiplexer 11.

When the processor 17 of the data processing circuit 22 finishes sending out the information previously stored in the RAM 18, it stops the carrier wave generator 16 via the boat 20, and stops the carrier wave being sent to the modulator 15.

Then, when the interrogator stops transmitting radio waves or the transponder moves out of the communicable range of the radio waves transmitted by the interrogator, and the time constant circuit 23 again transmits a low-level signal to the 5TBY terminal, it enters standby mode. , the clock etc. are stopped to reduce the current consumption of the data processing circuit 22 to several μA, but R
A current is supplied to AM18 to hold the memory contents.

Therefore, for example, if the time from when the transponder 4 shown in FIG. The time from receiving the signal to generating the carrier wave is TIl
Then, interference can be prevented by setting the constant of the time constant circuit 23 of the responder 4' so that TA<TB.

Note that the response devices are set so that, for example, the delay time becomes longer in sequence according to the order in which they are conveyed by a belt conveyor or the like.

〔Effect of the invention〕

As explained above, the present invention is applicable to the case where a plurality of transponders are brought into the communication range of the radio waves transmitted by one interrogator.
It is now possible to shift the transmission time period of the radio waves that each transponder sends to the interrogator, and to prevent the radio waves sent from multiple transponders from overlapping, the interrogator collects information without the risk of interference. I can do it.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of a circuit showing an embodiment of the invention, Fig. 3 is a block diagram explaining the conventional technology, and Fig. 4 is an example of a transponder. The block diagram to be explained, FIG. 5, is a diagram explaining the problem. In the figure, 1 is a computer system, 2 is an interrogator, 3.10 is an antenna, 4 is a responder, 5 is a pallet, 6 is a product, 7 is a belt conveyor, 8 is a sensor, 9 is a LOBE, 11 is a duplexer , 12 is a demodulator, 13 is an activation signal generation circuit, 17 is a processor, 18 is a RAM, 19 is a ROM,
20 is a port 21 is a delay means, and 23 is a time constant circuit. 20 moves of the blower 3 ■

Claims (1)

[Claims] The interrogator is brought into the communicable range of the radio waves transmitted by the interrogator, and upon receiving the radio waves, generates a carrier wave, modulates the carrier wave with preset information, and sends it to the antenna (10). and, in the transponder that responds to the question from the interrogator, a delay means (21) for delaying the time from when the interrogator receives the radio wave to when the carrier wave is generated by a preset time. If a plurality of transponders are brought into the communicable range of the radio waves transmitted by the interrogator, each of the plurality of transponders is set in the delay means (21). 1. A response method of a transponder in an object identification device, characterized in that the transponder responds to the interrogator in different time zones.