JP3576387B2 - Semiconductor circuit and moving object identification device provided with the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor circuit having a built-in lithium battery and a moving object identification device provided with the circuit.
[0002]
[Prior art]
A mobile object identification device is a device that performs reading and writing of a memory of a transponder from an interrogator in a non-contact manner using a wireless medium. As a product of the mobile object identification device, a satellite ID plate system has already been commercialized. Specifically, for example, when the interrogator reads data in an arbitrary area stored in the memory of the transponder, the interrogator transmits a read command, and the transponder receiving this command transmits the read command to the internal memory according to the content of the command. The communication is performed such that the data is pulled out from the server and the data is returned in the response.
[0003]
In the transponder of the moving object identification device, in order to prolong the life of the built-in lithium battery, in the operation standby state, the operation of the CPU is stopped and the mode is shifted to the sleep mode. In the sleep mode, only a memory backup is performed by supplying a very small current consumption of several μA. On the other hand, when performing communication processing, the CPU in the sleep mode enters the active mode, so that a current (eg, a current of about several tens of mA) that is several hundred to several thousand times that of the memory backup is supplied to drive the CPU and peripheral circuits. are doing.
[0004]
The lithium battery incorporated in the transponder has a characteristic that a conversion film is generated inside the lithium battery with the passage of time due to usage conditions such as current consumption and temperature, and the internal resistance of the battery increases. When the internal resistance increases, the voltage between the terminals of the battery decreases even though the remaining amount of the battery is sufficient, so that the battery cannot function as a normal power supply.
[0005]
If the CPU is constantly driven, no chemical conversion film is generated, but the battery life of the transponder becomes extremely short. Naturally, a battery whose life has expired cannot function as a product unless the battery is replaced, and cannot be sold as a product.
[0006]
Therefore, in the case of a system in which the interrogator and the transponder communicate with each other on a daily basis (for example, every day), a conversion film is not generated in the transponder, but the life of the battery is shortened.
[0007]
Also, if the transponder has not been used for a long period of time, or if the interrogator and the transponder rarely communicate with each other, the battery voltage of the transponder drops due to the chemical film. As a result, even if an attempt is made to use such a transponder, a warning is issued at the start of use that the battery voltage is low.
[0008]
The transponder includes a type in which the battery can be replaced and a type in which the battery and the circuit are all molded with resin. Since the molded battery and the circuit are integrally formed in a resin cabinet, the battery cannot be taken out. Therefore, once the voltage of the built-in battery drops, it is almost impossible to return the battery voltage to normal.
[0009]
The only way is to send commands continuously from the interrogator for several hours. If the CPU of the transponder is constantly running, the chemical conversion film disappears. However, such an operation requires a time of several hours for one transponder. Therefore, when the number of transponders is large, an enormous work time is required.
[0010]
In addition, there is a method in which the cabinet is destroyed to replace the built-in battery, and then molded again with resin. However, from the viewpoint of cost, this method is very expensive and is an unrealistic method.
[0011]
[Problems to be solved by the invention]
Furthermore, the transponder of the conventional mobile object identification device has the following problem.
[0012]
FIG. 4 shows a voltage change of a lithium battery incorporated in a transponder of a conventional mobile object identification device.
[0013]
In the transponder including the lithium battery in which the chemical conversion film is generated, the voltage is falling, and the voltage (V ₀ −ΔV) is lower than the normal voltage value V _{0 by} the voltage drop ΔV of the internal resistance.
[0014]
Immediately after the CPU becomes active mode (2) from a sleep mode (1), a moment to peak to decrease the voltage is much, as shown in FIG. 4, the voltage is at the moment the minimum voltage V _1. Thereafter, the voltage gradually recovers, and finally reaches a voltage (V ₀ −ΔV) lower than the normal voltage value V _{0 by} a voltage drop ΔV of the internal resistance.
[0015]
CPU becomes active mode (2) will operate at a low voltage including instantaneous minimum voltage V _1. Therefore, when the voltage of the lithium battery is checked for each communication in response to a command from the transponder, it is determined that the battery is running low even though the remaining battery level is sufficient, and a battery voltage drop warning is issued.
[0016]
In addition to the decrease in the battery potential due to the chemical conversion film, the voltage drop immediately after the CPU enters the active mode causes the transponder to malfunction even if the remaining battery level is sufficient.
[0017]
Therefore, at present, when the battery cannot be replaced, there is no way to ignore the battery voltage drop warning and continue using the battery, or replace the transponder itself. . Naturally, if the battery voltage drop warning is ignored and continued to be used, there is no problem with the remaining capacity of the battery based on the date of manufacture and the accumulated operating time. Only when it can be determined that the
[0018]
The present invention improves the transponder of the conventional mobile object identification device, eliminates the above-mentioned problems, discharges the activation current by inputting a command from the interrogator, and replaces the built-in lithium battery. It is an object of the present invention to provide a semiconductor circuit which can be refreshed and the voltage of a battery can be easily restored.
[0019]
[Means for Solving the Problems]
The semiconductor circuit of the present invention is a semiconductor circuit containing a lithium battery, a communication circuit for receiving a discharge start command from outside the semiconductor circuit, and an activation current for the lithium battery in response to the discharge start command. A control circuit that controls the discharge of the lithium battery in response to the discharge start command when the control circuit receives a discharge start command during discharge of the activation current by the control circuit. A response indicating that the activation current is discharging is returned, thereby achieving the above object.
The communication circuit may return a discharge start response in response to the discharge start command.
The control circuit may control discharge of the activation current by controlling a load between terminals of the lithium battery.
The control circuit controls the discharge of the activation current by limiting the time during which the activation current of the lithium battery is discharged after the voltage between the terminals of the lithium battery exceeds a predetermined threshold by a timer. You may.
The control circuit may control a communication process corresponding to a command other than the discharge start command during the discharge of the activation current.
The mobile object identification device of the present invention is a mobile object identification device including an interrogator and a transponder that returns a response in response to a command from the interrogator, wherein the transponder includes a lithium battery, A communication circuit that receives a discharge start command from the interrogator; and a control circuit that controls discharge of an activation current of the lithium battery in response to the discharge start command, wherein the communication circuit includes the control circuit During the discharge of the activation current, when receiving a discharge start command, in response to the discharge start command, returns a response indicating that the activation current of the lithium battery is discharging, thereby, The above object is achieved.
[0025]
Hereinafter, the operation will be described.
[0026]
According to the semiconductor circuit configured as described above, when a voltage drop occurs in the lithium battery built in the transponder of the moving object identification device due to the formation of a chemical conversion film, a command is transmitted from the interrogator to transmit the battery. The battery voltage can be easily returned to normal without taking out the battery.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0028]
FIG. 1 shows a configuration of a moving object identification device of the present invention.
[0029]
The mobile object identification device includes an interrogator 2 and a transponder 1 that returns a response in response to a command from the interrogator 2.
[0030]
Non-contact communication is performed between the interrogator 2 and the responder 1.
[0031]
The transponder 1 includes a lithium battery (not shown in FIG. 1; see FIG. 2) 60, a communication circuit 10 for receiving a discharge start command from the interrogator 2, and a lithium battery in response to the discharge start command. And a control circuit 30 for controlling the discharge of the 60 activation currents. The transponder 1 further includes a memory 20.
[0032]
The communication circuit 10 receives the command transmitted from the interrogator 2. The control circuit 30 reads data stored in the memory 20 based on the command sent from the communication circuit 10 and transmits the data from the communication circuit 10. The transmitted signal is received by the communication circuit 301 of the interrogator 2.
[0033]
A host device 33 such as a personal computer and the interrogator 2 can be connected via the ID controller 32. That is, the host device 33 such as a personal computer can control the interrogator 2 via the ID controller 32.
[0034]
The control circuit 302 of the interrogator 2 controls the communication circuit 301. For example, the control circuit 302 may control the communication circuit 301 based on a signal transmitted via the ID controller 32. The signal received by the communication circuit 301 is input to the control circuit 302.
[0035]
When the interrogator 2 reads data in an arbitrary area stored on the memory 20 of the responder 1, the interrogator 2 transmits a read command. When the transponder 1 receives the read command, the command is sent to the control circuit 30 via the communication circuit 10, and the control circuit 30 reads data from the internal memory 20 according to the content of the read command. The control circuit 30 sends the read data to the communication circuit 10, and the communication circuit 10 sends the data to the interrogator 2.
[0036]
FIG. 2 shows the configuration of the transponder 1 of the present invention in more detail.
[0037]
The transponder 1 is a semiconductor circuit. The present invention can be applied to semiconductor circuits other than the transponder.
[0038]
The transponder 1 has a built-in lithium battery 60. The transponder 1 includes a communication circuit 10 that receives a discharge start command from outside the transponder 1, and a CPU 30 that controls discharge of an activation current of the lithium battery 60 in response to the discharge start command.
[0039]
The communication circuit 10 receives a discharge start command from the interrogator (not shown in FIG. 2; see FIG. 1) 2. Further, the communication circuit 10 returns a discharge start response in response to the discharge start command. The communication circuit 10 can control the discharge of the lithium battery 60 from the interrogator 2 by receiving the discharge start command from the interrogator 2.
[0040]
The transponder 1 further includes a discharge load 40. The CPU 30 controls the discharge of the activation current by controlling the load (discharge load) 40 between the terminals of the lithium battery 60.
[0041]
The CPU 30 controls the discharge of the activation current based on the voltage between the terminals of the lithium battery 60 and the time management by the timer.
[0042]
The transponder 1 further includes a memory 20. The CPU 30 processes data in the memory 20.
[0043]
The CPU 30 can control a communication process corresponding to a command other than the discharge start command during the discharge of the activation current. For example, the CPU 30 can control the discharge load 40 to process data in the memory 20 during the discharge of the activation current.
[0044]
The transponder 1 further includes a battery voltage detection unit 50 that measures the voltage of the lithium battery 60. The communication circuit 10 transmits an output from the battery voltage detection unit 50 as data. When the data is output from the battery voltage detection unit 50, the data is sent to the CPU 30. The CPU 30 controls the discharging load 40 based on the data sent from the battery voltage detection unit 50, processes the data from the battery voltage detection unit 50 in parallel with the control, and modulates the modulation unit 103 of the communication circuit 10. Transmit to
[0045]
The communication circuit 10 includes a demodulation unit 101, a reception amplifier unit 102, and a modulation unit 103. Demodulation section 101 demodulates the received command and sends the demodulated command to reception amplifier section 102. The receiving amplifier unit 102 amplifies and outputs the command. The modulation unit 103 can modulate the data processed by the data processing circuit 30 and transmit the modulated signal to the interrogator 2 of the mobile unit identification device.
[0046]
The communication circuit 10 can return a discharge start response by the operation of the modulation unit 103 in response to the discharge start command by the operation of the demodulation unit 101.
[0047]
The operation of the interrogator 2 and the responder 1 of the mobile object identification device will be described with reference to FIGS.
[0048]
When a command is transmitted from the communication circuit 301 of the interrogator 2, the communication circuit 10 of the responder 1 receives the command. The demodulation unit 101 of the transponder 1 demodulates the received command and sends it to the reception amplifier unit 102. The command amplified by the receiving amplifier unit 102 is sent to the CPU 30. The CPU 30 controls the discharging load 40 based on the command. The discharge of the lithium battery 60 is performed while controlling the discharge load 40.
[0049]
By transmitting the discharge start command from the interrogator 2, it is possible to control the discharge of the lithium battery 60 in the transponder 1 of the mobile identification device from the interrogator 2 of the mobile identification device.
[0050]
FIG. 3 shows a step of discharging the lithium battery 60 in the transponder 1 shown in FIG.
[0051]
Hereinafter, the operation of the CPU 30 will be described with reference to FIGS.
[0052]
When the interrogator (not shown in FIGS. 2 and 3; see FIG. 1) 2 sends any command to the transponder 1, the CPU 30 of the transponder 1 enters the CPU activation interrupt state 201. The transponder 1 that has gone through the CPU activation interruption state 201 enters a command reception waiting state 202. Next, a state 203 is determined in which it is determined whether or not a predetermined time has elapsed in the command reception standby state 202 (reception standby time has elapsed). If no command is received for a certain period of time, the process proceeds to the CPU sleep transition state 207, and the CPU 30 enters the sleep mode.
[0053]
When a command is transmitted from the interrogator 2 in the command reception standby state 202, the command is demodulated by the demodulation unit 101 and amplified by the reception amplifier unit 102.
[0054]
When the demodulated command is transmitted from the reception amplifier unit 102 to the CPU 30, the state is changed to a state 204 in which it is determined whether the command has been normally received. If the command is normally received, the process proceeds to a state 205 for determining whether the command is a discharge start command. If the command is not received normally, the process returns to the command reception waiting state 202.
[0055]
When it is determined in the state 205 that the command is not the discharge start command and the command is not the discharge start command, the state becomes the state 206 in which the conventional processing according to the command is performed, and the CPU 30 performs the processing based on the command. Execute. After the processing is completed, the process proceeds to the CPU sleep transition state 207, and the CPU 30 enters the sleep mode.
[0056]
If it is determined in step 205 that the command is a discharge start command, if it is determined that the command is a discharge start command, the state becomes a state 208 of transmitting a discharge start response, and the transponder 1 transmits the interrogator 2 via the communication circuit 10. , A discharge start response is transmitted as a signal. Thereafter, the state becomes the activation current discharge start state 209, and the discharge of the lithium battery 60 is started.
[0057]
The transponder 1 returns a response in response to the command from the interrogator 2. Specifically, when the interrogator 2 transmits a discharge start command to the transponder 1, the transponder 1 having received the discharge start command transmits a discharge start response to the interrogator 2 prior to discharging the lithium battery 60. I do.
[0058]
The CPU 30 controls the discharge of the activation current by controlling the load 40 between the terminals of the lithium battery 60. Under the control of the CPU 30, the load 40 between the terminals of the lithium battery 60 is increased, and a specified current is passed to the extent that the chemical conversion film can be extinguished. As the load 40 at this time, a method may be used in which the CPU 30 itself is set as a load by setting the CPU 30 in an active mode, and a discharging load 40 having a resistor (not shown) is connected between terminals of the lithium battery 60 to load the load. May be used.
[0059]
After the activation current discharge start state 209, a command reception standby state 210 is set. Thereafter, the process proceeds to a state 211 in which timer adjustment control based on battery voltage measurement is performed. Based on the result of measuring the voltage of lithium battery 60 by battery voltage detection unit 50, CPU 30 adjusts and controls a timer.
[0060]
As described above, the CPU 30 controls the discharge of the activation current based on the voltage between the terminals of the lithium battery 60 and the time management by the timer. Specifically, the timer is operated by the CPU 30 until the amount of discharge required for the disappearance of the chemical conversion film flows to the lithium battery 60, and the lithium battery 60 is discharged while controlling the time. The discharge time is not simply determined as a fixed time after receiving the command, but the voltage of the lithium battery 60 is checked while discharging while using a timer. When the voltage of the lithium battery 60 rises above a threshold at which a warning of a battery voltage drop is issued, the CPU 30 further performs a time limit by a timer to perform a minimum discharge. In other words, by performing the discharge to such an extent that the consumption of the lithium battery 60 is minimized without performing unnecessary discharge, it is possible to prevent a warning that the battery voltage is low due to insufficient discharge from being issued again in a short time. To do.
[0061]
Thereafter, the process proceeds to the state 212 in which it is determined whether or not the discharge is completed based on the battery voltage measurement result and the elapsed time. When the discharge of the built-in lithium battery 60 of the transponder 1 is completed, the process proceeds to the CPU sleep transition state 207, the CPU 30 enters the sleep mode, and returns to the normal standby state.
[0062]
If the discharge has not been completed, the CPU 30 continues to wait for receiving a command while discharging the lithium battery 60. When the command is received, the command is transmitted from the reception amplifier unit 102 to the CPU 30 as described above. Thereafter, the process proceeds to a state 213 where it is determined whether or not the command has been normally received. If the command has been successfully received, the process proceeds to a state 214 where it is determined whether or not the command is a discharge start command. If the command has not been received normally, the process returns to the command reception waiting state 210, and the CPU 30 again waits for a command input.
[0063]
If it is determined in the state 214 that the input command is the discharge start command in the state 214 for determining whether or not the command is the discharge start command, the state is changed to a state 216 for transmitting a response indicating that the discharge is being performed. A response indicating that the discharge is being performed is transmitted to the interrogator 2 via the reference numeral 10. After transmitting the response, the process returns to the command reception waiting state 210 again.
[0064]
If it is determined that the input command is not the discharge start command in the state 214 for determining whether or not the command is the discharge start command, the process proceeds to the state 215 for performing the conventional processing, and the CPU 30 determines based on the input command. Perform normal processing. After the execution of the processing, the process returns to the command reception waiting state 210 again.
[0065]
The CPU 30 can control a communication process corresponding to a command other than the discharge start command during the discharge of the activation current. That is, the state from the command reception standby state 210 to the conventional processing 215 is different from the state from the command reception standby state 202 to the conventional processing 206, and the CPU 30 performs other processing while discharging the lithium battery 60. It is in a state where it can be done.
[0066]
In other words, by controlling the discharge of the lithium battery 60 and performing the conventional processing based on the command input via the communication circuit 10 in parallel with the CPU 30, the lithium battery 60 Even if a long time (for example, several hours) is required for the discharge, the CPU 30 can execute communication processing corresponding to a command other than the discharge start command without being limited to this processing time.
[0067]
Therefore, according to the transponder of the mobile object identification device of the present invention, when the mobile object identification device is used in a production line or the like, discharge of the lithium battery and normal processing can be performed simultaneously.
[0068]
For example, when using a transponder of a mobile identification device in a factory automation system, a self-diagnosis test of the transponder is generally performed on a line, and a memory check and a battery voltage check of the transponder are often performed. At this time, when the battery voltage drop warning occurs, the battery date is actually lowered by reading the date of manufacture of the transponder and the accumulated operation time data, or the voltage apparently drops due to the chemical conversion film. Can be easily determined.
[0069]
Therefore, according to the present invention, when the battery voltage is lowered by the chemical conversion film, if the discharge of the lithium battery is immediately executed by the discharge start command, the discharge of the lithium battery is simultaneously performed while the original operation is performed in the line thereafter. can do. As a result, the refresh of the lithium battery is completed several hours later without any problem. In other words, the conventional processing via communication can be executed without any trouble even during the discharging of the lithium battery, so that the line can be continuously used even during the discharging.
[0070]
Further, according to the transponder of the mobile object identification device of the present invention, the lithium battery can be refreshed by a simple method without taking out the lithium battery.
[0071]
For example, if the transponder is stored without being used for a long time, the battery voltage will be checked before delivery. When the battery voltage drop due to the chemical conversion film occurs, the battery can be delivered as it is without any problem by transmitting a discharge start command to refresh the battery. Since the lithium battery can be refreshed by a very simple operation without taking out the lithium battery, even when checking the transponder before delivery, anyone can check the transponder by a simple procedure. Therefore, even the sales department and the service department can check the transponder before delivery without requiring advanced technical knowledge.
[0072]
【The invention's effect】
According to the semiconductor circuit of the present invention, a discharge start command is received from outside the semiconductor circuit, and the discharge of the activation current of the lithium battery can be controlled in response to the discharge start command. Thus, the lithium battery can be refreshed by a very simple operation without taking out the lithium battery.
[0073]
Further, according to the semiconductor circuit of the present invention, even if the internal resistance of the lithium battery increases and the terminal voltage decreases, the conversion film can be extinguished by discharging a certain amount of activation current, and The battery voltage can be returned to a normal value. That is, even if the device has a built-in lithium battery whose terminal voltage has been reduced because it has not been used for a long period of time, it can be made usable by discharging the lithium battery. That is, what could not be delivered as a product in the past can be delivered as a product having no problem in quality.
[0074]
Further, according to the semiconductor circuit of the present invention, the control circuit can control a communication process corresponding to a command other than the discharge start command during the discharge of the activation current. Thus, communication processing is possible even during the discharge of the lithium battery, and the lithium battery can be discharged without affecting the operating system.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a moving object identification device of the present invention.
FIG. 2 is a diagram showing the configuration of the transponder 1 of the present invention in further detail.
FIG. 3 is a diagram showing a step of discharging a lithium battery 60 in the transponder 1 shown in FIG.
FIG. 4 is a diagram showing a voltage change of a lithium battery incorporated in a transponder of a conventional mobile object identification device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Communication circuit 20 Memory 30 Control circuit 40 Discharge load 50 Battery voltage detector 60 Battery

Claims (6)

A semiconductor circuit containing a lithium battery, a communication circuit for receiving a discharge start command from outside the semiconductor circuit, and a control circuit for controlling discharge of an activation current of the lithium battery in response to the discharge start command And a semiconductor circuit comprising:
The communication circuit, when receiving the discharge start command during the discharge of the activation current by the control circuit, indicates that the activation current of the lithium battery is discharging in response to the discharge start command. A semiconductor circuit that returns a response . The semiconductor circuit according to claim 1, wherein the communication circuit returns a discharge start response in response to the discharge start command. 2. The semiconductor circuit according to claim 1, wherein the control circuit controls discharge of the activation current by controlling a load between terminals of the lithium battery. 3. The control circuit controls the discharge of the activation current by limiting the time during which the activation current of the lithium battery is discharged after the voltage between the terminals of the lithium battery exceeds a predetermined threshold by a timer. The semiconductor circuit according to claim 1. 2. The semiconductor circuit according to claim 1, wherein the control circuit controls a communication process corresponding to a command other than the discharge start command during the discharge of the activation current. An interrogator and a mobile object identification device including a transponder that returns a response in response to a command from the interrogator, wherein the transponder transmits a lithium battery and a discharge start command from the interrogator. A communication circuit for receiving, and a control circuit for controlling discharge of the activation current of the lithium battery in response to the discharge start command, wherein the communication circuit is configured to discharge the activation current by the control circuit. A moving body identification device that, when receiving a discharge start command, returns a response indicating that the activation current of the lithium battery is discharging in response to the discharge start command .

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