JPH08175085A - Contactless signal coupler and electronic apparatus system - Google Patents

Abstract

PURPOSE: To improve the transmission efficiency of a signal coupler using a sheet coil and to make progress of the performance of an electronic apparatus system having such a coupler by providing a magnetic sheet having high permeability on the back surface side of the coil. CONSTITUTION: Even if an interval between sheet coils 5a and 6a is the same as that between contactless signal couplers 5 and 6, the quantity of a magnetic flux which can pass the coil of the secondary side of that generated from the coil of the primary side, i.e., electromagnetic bonding force is remarkably increased since the sheets 5b, 6b of high permeability materials are extended to the back surface of the coils. Thus, a signal transmission gain between the coils 5a and 6a is increased, and the power level of the signal obtained from the coil of the secondary side is increased. Since the sheets 5b, 6b perform functions of magnetic shields for covering the back surface side with respect to the coils 5a, 6a, it is scarcely affected by the electromagnetic noise, whereby the S/N ratio is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contactless signal coupler which enables signal transmission to and from an external device without a conductive connection, and an IC card or a print equipped with such a signal coupler. The present invention relates to an electronic device system having a substrate and the like, and is particularly useful for an electronic blackboard system.

[0002]

2. Description of the Related Art It is easiest to use mechanical contacts as a signal coupler for externally inputting / outputting information to / from an independent device such as an IC card having a built-in electronic circuit such as PROM or MPU. is there. However, the contacts are vulnerable to dirt and abrasion and have a problem with reliability. On the other hand, the photocoupler is a signal coupler that is resistant to dirt and abrasion, but there are problems in that it cannot be applied to a sheet-like object such as an IC card and cannot be used for power supply of a power source because of its thickness. It was Therefore, an electromagnetic signal coupler using a sheet coil, which can be easily thinly formed on the surface of an arbitrary object by printed wiring, has been widely used.

FIG. 14 is an explanatory view of a conventional signal coupler using a sheet coil, and FIG. 14 (a) shows the sheet coil as seen from the upper surface and formed in a spiral shape. FIG. 1B shows an example of a printed circuit board provided with a sheet coil. In the figure, 1 and 2 are two printed circuit boards for signal coupling, and 3a, 3b and 3c are three printed circuit boards formed on the printed circuit board 1. Sheet coils 4 are ICs to which each sheet coil is connected. Sheet coils corresponding to the sheet coils 3a, 3b, 3c of the printed board 1 are also provided in the printed board 2. FIG. 3C shows a cross section of the printed circuit boards 1 and 2 shown in FIG. 2B when cut laterally at the portion of the sheet coil 3a. 3a 'in the figure
Indicates a sheet coil provided at a position in the printed board 2 facing the sheet coil 3 a in the printed board 1.

When signal coupling is performed between two printed circuit boards, the printed circuit boards 1 and 2 are stacked with the sheet coils 3a and 3a 'properly facing each other as shown in FIG. 14 (c). To match. As a result, the two sheet coils 3a and 3a 'can be electromagnetically coupled to each other.
Since one transformer is configured as shown in FIG. 5, signal transmission can be performed between the printed boards 1 and 2 without contact or contact.

However, the number of turns of the sheet coils 3a and 3a 'that can be formed by the printed wiring is as small as several tens of turns, and since the magnetic permeability of the surrounding material is small in the air core, the inductance of the sheet coils 3a and 3a' is small. It is not possible to make mutual induction between 3a and 3a 'sufficiently large, and it is used for ordinary signal transmission in IC cards and the like. The transmission efficiency at a frequency of about 100 KHz was considerably low. This low transmission efficiency is particularly problematic when power is supplied from a power source to a printed circuit board that does not contain a battery via a sheet coil.

In the recent electronic blackboard system, a necessary number of types of IC cards called chips in which individual data such as names and item names are written are attached to the board surface of the electronic blackboard to visually create a table. Some have made it possible to automatically read individual data from the IC of the attached chip and perform data processing on the table.

As described above, in the electronic blackboard system, since the individual data assigned to the chips are various, conventionally, a part of the IC in the chip is used as the RAM, and the R for each chip.
The method of writing the individual data assigned to the AM has been adopted. For this reason, it is necessary to provide a data read / write control circuit on the chip, which makes the chip and the electronic blackboard circuit plural and expensive. In addition, the RAM requires a battery to make the stored data non-volatile.
The AM capacity must be sized according to the maximum value of the data length of individual data, and increasing the memory capacity will increase battery consumption and shorten the chip life, while limiting the memory capacity to a small value. Then, there arises a problem that the allowable data length of the individual data is limited.
Further, in the RAM, since the stored data may be destroyed by static electricity, there is a problem in the stability of the information held by the chip.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the transmission efficiency of a signal coupler using a sheet coil and to improve the system performance of electronic devices equipped with such a signal coupler. There is.

Further, according to the present invention, in the electronic blackboard system, the circuit configuration is simplified, the power consumption of the chip is reduced, the life of the chip is lengthened, and the memory length is small without limiting the data length of individual data. The purpose is to enable flexible allocation of various individual data to each chip and to stabilize the information stored in the chip.

[0010]

SUMMARY OF THE INVENTION The present invention is a contactless signal coupler using a sheet coil for non-conductive signal coupling between devices of an electronic device system such as an electronic blackboard system. By providing a magnetic sheet with high magnetic permeability on the side, the signal transmission efficiency is improved.

According to another aspect of the present invention, in an electronic blackboard system, information to be written in each chip is identification information unique to the chip, which is independent of individual data used in actual processing,
After reading this unique identification information from the chip, it is converted into predetermined individual data by the conversion table. As a result, the data held in the memory in the chip only needs to have a data length that can identify each chip, and the individual data assigned to the chip is registered only in the conversion table.
By putting this conversion table on the electronic blackboard side so that it can be rewritten arbitrarily, it is not necessary to rewrite the identification information held in the memory of the chip.

FIG. 1 is an explanatory diagram showing the basic configuration of the present invention by an exemplary method. FIG. 1 (a) is a schematic view of a contactless signal coupler according to the present invention, in which 1 and 2 are printed circuit boards, which are detachable and independent from each other for signal transmission. It is a device.

Reference numeral 4 is an IC. Reference numerals 5 and 6 are contactless signal couplers used so as to face each other. 5a
Sheet coils 6 and 6a form a coil on the primary side and a coil on the secondary side of the transformer when coupled, and enable signal transmission.

Reference numerals 5b and 6b are magnetic sheets of a high magnetic permeability material, and a magnetic material such as permalloy having a high μ in the transmission signal frequency band is used. The magnetic sheets are provided along the back surfaces of the sheet coils 4a and 5a, respectively.

FIG. 1 (b) is a sectional view showing an operating state in which the printed circuit board 1 and the printed circuit board 2 of FIG. 1 (a) are connected, and the sheet coils 5a and 6b are closely and face each other. There is.

FIG. 1C is an explanatory view of the electromagnetically coupled state, and 7 and 8 in the figure show average magnetic paths of magnetic flux. Magnetic sheet 5 provided on the back surface of each sheet coil 5a, 6a
By b and 6b, the electromagnetic coupling force of the sheet coils 5a and 6a is increased, and the signal transmission efficiency is improved.

FIG. 1D is a schematic diagram of the electronic blackboard system according to the present invention. In the figure, 10 is an electronic blackboard and 12 is a chip. The chip 12 has a memory 12a in which identification information unique to the chip is written. When the chip 12 is attached to the electronic blackboard 10, the memory 12a is identified. Information is read into the electronic blackboard 10. The read identification information is converted into arbitrary individual data by the conversion table 10a. The conversion table 10a is placed in the electronic blackboard 10a or in a processing device (not shown) to which the electronic blackboard 10 is connected and is rewritable.

[0018]

As shown in FIG. 1 (c), in the contactless signal coupler according to the present invention, even if the distance between the sheet coils 5a and 6a is the same, the magnetic flux generated by the primary side sheet coil is generated. The amount of magnetic flux that can penetrate the secondary side sheet coil, that is, the electromagnetic coupling force is remarkably increased by the magnetic sheets 5b and 6b made of a highly magnetically permeable material extending to the back surface of each sheet coil. As a result, the signal transmission gain between the sheet coils 5a and 6a is increased, and the power level of the signal obtained from the secondary side sheet coil is increased.

Further, since the magnetic sheets 5b and 6b also function as magnetic shields that cover the back side of the sheet coils 5a and 6a, they are less susceptible to electromagnetic noise and S / N is improved.

Further, as shown in FIG. 1 (d), in the electronic blackboard system according to the present invention, it is sufficient that the chip 12 stores unique identification information that does not need to be rewritten. The chip corresponding individual data required according to the
Can be arbitrarily assigned to.

For this reason, a writing control system to the chip is unnecessary, the system configuration is simplified, and the conversion table 10a can be easily updated, so that flexible operation is possible. In addition, the memory 1 of the chip 12 for storing identification information
Information can be easily stabilized by configuring 2a with a PROM or the like.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic blackboard system will be described below as an embodiment of an electronic device system provided with a contactless signal coupler according to the present invention.

In this embodiment of the electronic blackboard system, an electronic information card called a chip equipped with a memory IC or the like is attached to the board surface of the electronic blackboard system to exchange signals with the electronic blackboard system, and the items are transferred from the chip. Data such as name and name can be automatically input, and it is possible to remarkably simplify the creation of a control table and the data input in, for example, labor management or process management.

FIG. 2 is a system schematic diagram of the electronic blackboard system, and FIG. 2A shows the front surface of the electronic blackboard.
(B) indicates the side surface. In FIGS. 2A and 2B, 10 is an electronic blackboard (the front surface is a whiteboard), and 11 is provided for each of a plurality of cells arranged in a grid on the board surface of the electronic blackboard 10. Driver / sensor DR / SN, 12 is a chip that can be attached to an arbitrary cell of the lattice, 13 is a chip controller that controls the acquisition of information from the chip, 13a is a conversion table, 14 is a data processing device, 15 is an MPU, and 16 is The memory 17 is a keyboard. Here, a case where a management table is constructed on the electronic blackboard will be described as an example.

The built-in memory of each chip 12 stores ID (identification) information unique to the chip, and the electronic blackboard such as the name, product name and process name assigned to the chip is stored on the surface of the chip. The individual data that is the element of the management table to be created is described above. A management table that can be visually recognized is created by attaching a required number of such various chips 12 to appropriate cell positions on the board surface of the electronic blackboard.

The chip controller 13 is an electronic blackboard 10.
The DR / SN 11 of each cell is scanned, the ID information is fetched from the chip attached to the cell, converted into individual data assigned to the chip using the conversion table 13a, and the position information of the chip is read. Along with it, it is transferred to the data processing device 14. The data processing device 14 builds a management table in the memory 16 from the ID information and the position information, and processes the data input from the keyboard 17 in a conversation with the operator. The conversion table 13a
May be provided in the data processing device 14.

FIG. 3 is an external view of the chip 12, and FIG.
3A shows the front surface of the chip, and FIG. 3B shows the back surface of the chip. As shown in FIG. 3A, the chip surface is
An ID such as a name is written in characters or symbols. This clerk may be easily rewritten. Further, as shown by 18 and 19 in FIG. 3B, the contactless signal coupler composed of the sheet coil and the magnetic sheet described in FIG. 1 is provided on the back surface of the chip, and each sheet coil is inside the chip. Is connected to the IC 20 embedded in the. The contactless signal combiner 18 is used for power supply, and the contactless signal combiner 19 is used for reading ID information. Further, as shown by 21a and 21b, pins such as magnets or soft iron that are sensitive to magnetic force are provided on the back surface of the chip, and the magnetic force provided corresponding to each cell position on the board surface of the electronic blackboard 10 is provided. The chip can be magnetically attracted to the board surface by acting with a member or a magnet that is sensitive to.

FIG. 4 is a block diagram of the chip circuit.
Is an operation waveform diagram thereof. In FIG. 4, 18a is a power coil and 19a is a lead coil, which correspond to the sheet coils in the contactless signal couplers 18 and 19 of FIG. 3, respectively. Further, 21 is a serial PROM, 22 is a power supply circuit, 2
Reference numeral 3 is a clock extraction circuit, and 24 is a read circuit.

The serial PROM 21 continuously outputs the data stored therein to the data terminal serially in a bit series in accordance with the clock input to the clock terminal (see the waveform of FIG. 5C). (See the waveform in (d)).

A pulsed magnetic field having a constant period (for example, 10 μs) is applied to the power supply coil 18a from the driver DR of the electronic blackboard. The power supply circuit 22 rectifies the pulse voltage (see the waveform of FIG. 5A) induced in the power supply coil 18a and converts it into a DC voltage, and the power supply terminals of the serial PROM 21, the clock extraction circuit 23, and the readout circuit 24. Supply to.

The clock extraction circuit 23 includes a power supply coil 18
The pulse voltage output from a is inverted (see the waveform in FIG. 5B), further divided by 1/2 to perform waveform shaping to extract the clock (see the waveform in FIG. 5C), and the serial PROM 2
1 to the clock terminal. The serial PROM 21 starts the operation of reading data from the time when the clock is applied.

The read circuit 24 is a serial PROM 2
The output data from 1 (see the waveform in FIG. 5D) is converted into a signal (see the waveform in FIG. 5E) to drive the lead coil 19a and transmit it to the sensor SN of the electronic blackboard.

The configuration of the chip circuit shown in FIG. 4 does not require a built-in power source such as a battery, uses a serial PROM for the memory, and adds transmission control information to the stored data itself (described later). With this, the read control circuit of the memory and the transfer control circuit of the read data can be eliminated, and the configuration is extremely simple.

By the way, since both the power supply power and the clock are obtained from the induced voltage of the power supply coil 18a, the frequency of the pulse magnetic field for driving the power supply coil 18a, that is, the drive frequency of the driver DR of the electronic blackboard is either the clock frequency or the It is convenient to use a frequency twice the clock frequency as in the circuit of FIG. However, since the inductance of the sheet coil of the non-contact signal coupler is still very small because the air gap remains even if the magnetic sheet is provided, the resonance frequency becomes considerably high. In the electromagnetic coupling type contactless signal coupler, the transmission efficiency decreases as the drive frequency moves away from the resonance frequency. Therefore, when the drive frequency is lower than the resonance frequency in the circuit of FIG. There is a problem.

The chip circuit having the configuration shown in FIG. 6 is an improvement of this point, in which a clock oscillation circuit 25 is provided instead of the clock extraction circuit 23 in the circuit configuration of FIG. The clock oscillation circuit 25 generates a clock of 100 KHz, for example, for the serial PROM 21 by self-excited oscillation, and the power supply coil 18 a is used only for supplying power to the power supply circuit 22. Therefore, the power coil 1
Driver DR for contactless signal combiner 18 including 8a
It is possible to use a frequency that can be expected to have a higher transmission efficiency, such as 1 MHz, as the driving frequency of. However, in this circuit, the clock is asynchronous to the chip controller 13.

FIG. 7 is an explanatory diagram showing a basic data format of data stored in the serial PROM 21. In order to eliminate the need to provide a read data transfer control circuit in the chip, the data itself is stored in the serial PROM 21 in the asynchronous transmission data format in which a preamble and a postamble are added in advance, and the read data is directly stored in the chip controller. Asynchronous transmission to 13 is possible. In the illustrated basic data format, the preamble indicates the beginning of data transfer, and is composed of all “1” with the number of bits equal to or more than (bit width of data + bit width of parity bit P), and data represents all types of ID information. The number of bits that can be identified and the postamble indicate the end of data transfer, and are configured by all “0” of the number of bits of (data bit width + parity bit bit width) or more.

FIG. 8A is an explanatory diagram showing a multi-data format when the ID information is composed of a plurality of data 1, 2, ..., N. Each data is separated by a start bit S, and a preamble and a postamble are added to the entire data.

If the number of bits of the serial PROM 21 is larger than the number of bits of the data to be transferred, FIG.
As shown in, the same data frame is repeated multiple times to form a multi-frame format.

FIG. 9 is a circuit configuration diagram of the chip controller 13 in FIG. In FIG. 9, the chip controller 13 includes a CPU circuit 26, a memory 27, a chip control circuit 28, a console 29, and an interface 30.

The CPU circuit 26 is the chip controller 1
3. Control of the whole 3 and processing of converting the ID information fetched from the chip 12 into predetermined code data, and command and data transmission / reception control with the data processing device 14 are performed.

The memory 27 is used to store ID information, a conversion table of ID information and individual data, and other work data. The chip control circuit 28 scans a group of drivers / sensors DR / SN11 of the electronic blackboard 10 to drive the attached chip 12, receives signals from the chip 12, and controls to take in ID information. Details will be described later.

The console 29 has key switches for operation and a display for displaying control information and messages. The interface 30 controls signal transfer with the interface 31 in the data processing device 14.

FIG. 10 shows the driver / sensor DR / SN1.
2 is a circuit configuration diagram of FIG. In FIG. 10, the driver / sensor DR / SN 11 includes a drive coil 32, a sense coil 33, a coil drive circuit 34, and a coil sensor circuit 35.
It is composed of

Drive coil 32 and sense coil 3
Reference numeral 3 is a sheet coil of the contactless signal coupler shown in FIG. 1, and the respective attached chips face the power supply coil 18a and the lead coil 19a shown in FIG.

The coil drive circuit 34 inputs the coil drive signal sent from the chip controller 13 to drive the drive coil 32 by power switching. The coil sensor circuit 35 amplifies and shapes the signal induced in the sense coil 33 and sends it to the chip controller 13 as sense information.

FIG. 11 is a circuit configuration diagram of the chip control circuit 28 in the chip controller 13 shown in FIG. The general operation will be described below. The chip address counter 36 is a driver arranged in each grid cell of the electronic blackboard 10 shown in FIG. 2 according to an instruction from the CPU circuit 26.
Chip addresses for scanning the sensor DR / SN are continuously generated. This chip address is added to the decoder / selector circuit 37 and the data selection circuit 39, respectively. The decoder / selector circuit 37 sends the coil drive signal generated from the oscillator circuit 38 to one driver / sensor DR / SN corresponding to the given chip address. The data selection circuit 39 also selects the sense information output from the same driver / sensor DR / SN and sends it to the sense timing circuit 40. The chip circuit is assumed to have the structure shown in FIG. Therefore, here, the sense timing circuit 40 can synchronously detect the bits in the sense information by using the coil drive signal output from the oscillation circuit 38, and sequentially output the bit value of the detection result to the serial-parallel conversion circuit 41. Send out.

The serial-parallel conversion circuit 41 converts the input serial data into parallel data, and the preamble detection circuit 42, the start bit detection circuit 43, the parity bit check circuit 44, the postamble detection circuit 45, and the data register 46 are converted into parallel data. The data is sent, the input data is analyzed in accordance with the basic data format or the multi-data format, data having no parity error is extracted, and read into the same detection circuit 47 twice consecutively. Identical detection circuit 4 twice consecutively
7 compares the sequentially read data with the previous data, detects whether they are the same, and outputs the result to the CPU circuit 2
Send to 6.

FIG. 12 is a detailed circuit diagram of a specific example of the chip circuit having the configuration shown in FIG. In FIG. 12, 48
Is a sheet coil corresponding to the power supply coil 18a in FIG. 4, and a coil having 40 turns is used. Then 49
Is a rectifier diode, 50 is an overvoltage protection diode, 51
Are smoothing capacitors, and these are the power supply circuit 22 of FIG.
Is configured. Next, 52 is an inverting circuit and 53 is a D-FF, which constitute the clock extraction circuit 23 of FIG.
Reference numeral 54 is an EPROM, which is the serial PROM 21 of FIG.
Equivalent to. Reference numeral 55 is a D-FF, which corresponds to the read circuit 24 in FIG. 56 is a sheet coil corresponding to the lead coil 19a in FIG.
A coil of turns is used.

Next, a concrete example of a conversion table for converting the unique ID information stored in the chip into individual data is shown in FIG.
This will be described below. FIG. 13A shows the basic individuality of the conversion table, and gives the correspondence between the unique ID information of each registered chip and the individual data assigned to it. When the chip ID information is input to the chip controller,
The conversion table is searched using the ID information as a key, and the individual data of the entry having the same ID information as the input ID information is output.

FIGS. 13B and 13C show an example of changing the individual data to be assigned to the chip, and FIG.
ID in the PROM of the chip to be changed in the state before the change
= 117 is written, and "B work" is written on the surface of the chip. On the other hand, the conversion table shows "ID
= 15 ”,“ D = 117 ”, and“ ID = 308 ”, the ID information of the three chips and the individual data“ A ”corresponding to each of them.
"Work", "B work", and "C work" are registered. Here, it is assumed that the individual data assigned to the "B work" chip is changed to "D work".

FIG. 13C shows the state after the change. The ID information (“117”) of the PROM of the chip is not changed, only the notation is changed to “D work”, and the ID of the conversion table is 117. The entry having "" is rewritten so as to correspond to the individual data "D work".

FIG. 13D shows an example of registering a new chip. ID = 25 for PROM of new chip
7 is written, and “F work” is described as individual data. As a result, the conversion table shows “ID =
An entry associating "257" with "F work" is added.

As described above, the conversion table can be easily changed and added, and similarly, the chips registered in the conversion table can be deleted.

[0054]

According to the present invention, the signal transmission efficiency of the contactless signal coupler can be remarkably enhanced by a simple means of adding a magnetic sheet to the sheet coil. Further, since the noise is reduced by the magnetic shielding effect of the magnetic sheet, the signal-to-noise ratio can be improved. Since the magnetic sheet is thin, even if it is applied to an IC card or the like, the total thickness does not need to be increased so much, and the increase in cost caused thereby is slight.

According to the present invention, a write circuit for the chip, a command analysis function of the chip, and a memory write function are unnecessary, so that a simple and inexpensive system can be provided.

According to the present invention, since a writing circuit for the chip and a memory write function are unnecessary, there is no problem of data destruction due to static electricity of the chip, and a highly reliable system can be provided.

According to the present invention, since the chip does not have a battery, the life of the battery is not limited by the life of the battery, and a long-life chip can be provided. According to the present invention, by storing the data originally necessary for the chip in the conversion memory, when the information amount of the data increases, it is possible to easily cope with the change in the data amount by increasing the capacity of the inexpensive memory.

Further, by applying such a non-contact signal combiner to a large number of inter-device signal combiners in an electronic device system such as an electronic blackboard system, system reliability can be improved and drive power can be reduced. Therefore, the weight of the entire system can be reduced.

Further, in the electronic blackboard system, only the unique ID information is stored in the chip, and the electronic blackboard side allocates it to arbitrary individual data, thereby simplifying the overall system structure and reducing the cost. Improves reliability and flexibility.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is a system schematic diagram of an electronic blackboard system according to an embodiment of the present invention.

FIG. 3 is an external view of a chip.

FIG. 4 is a configuration diagram of a chip circuit.

FIG. 5 is an operation waveform diagram of the chip circuit.

FIG. 6 is another configuration diagram of the chip circuit.

FIG. 7 is an explanatory diagram of a basic data format.

FIG. 8 is an explanatory diagram of a multi-data format and a multi-frame format.

FIG. 9 is a circuit configuration diagram of a chip controller.

FIG. 10 is a circuit configuration diagram of a driver / sensor DR / SN.

FIG. 11 is a circuit configuration diagram of a chip control circuit.

FIG. 12 is an explanatory diagram of a specific example of a chip circuit.

FIG. 13 is an explanatory diagram of a specific example of a conversion table.

FIG. 14 is an explanatory diagram of a signal combiner using a conventional sheet coil.

[Explanation of symbols]

 1, 2 Printed circuit board 4 IC 5, 6 Non-contact signal coupler 5a, 6a Sheet coil 5b, 6b Magnetic sheet

Claims (11)

[Claims] 1. A contactless signal coupler for transmitting a signal between independent electronic devices, comprising a sheet coil and a magnetic sheet of a high magnetic permeability material provided along a back surface of the sheet coil. A non-contact signal coupler characterized in that 2. An electronic device system comprising a plurality of independent electronic devices for signal transmission between devices, wherein each electronic device has a side surface for signal coupling, a sheet coil, and a back surface of the sheet coil. An electronic device system comprising a contactless signal coupler formed of a magnetic sheet of a high magnetic permeability material provided as described above. 3. The plurality of electronic devices according to claim 2,
One is an IC card, which is an electronic device system. 4. The plurality of electronic devices according to claim 2,
One is an electronic device system, which is a printed circuit board. 5. The electronic device according to claim 2, wherein one of the electronic devices comprises means for rectifying a signal supplied from another electronic device via a contactless signal coupler to obtain power supply power. Characteristic electronic device system. 6. The one of the plurality of electronic devices according to claim 2.
One is an electronic blackboard, the other one is an electronic blackboard chip, and each of the electronic blackboard and the electronic blackboard chip is provided with a magnetic attraction means, and the electronic blackboard chip is provided with an IC and has no contact. An electronic device system characterized by being connected to a signal combiner. 7. An electronic blackboard system comprising an electronic blackboard and a chip that can be attached to the surface of the electronic blackboard and can perform signal transmission with the electronic blackboard, wherein the chip stores unique identification information. The electronic blackboard has means for reading the unique identification information from the chip, and the read unique identification information is converted into arbitrary individual data using a conversion table. Electronic blackboard system. 8. An electronic blackboard, an electronic blackboard chip that can be attached to the surface of the electronic blackboard, and a chip controller that controls reading of information from any electronic blackboard chip attached to the electronic blackboard. In an electronic blackboard system, a chip for an electronic blackboard has a memory in which unique identification information is stored, a means for supplying a clock to the memory, and a unique contactless signal combiner for the unique identification information read from the memory. And means for rectifying a signal supplied from the electronic blackboard through another non-contact signal coupler to obtain power source power, and has no information writing control means. Electronic blackboard system to do. 9. The memory according to claim 8, wherein the memory is a serial P
An electronic blackboard system which is a ROM and stores unique identification information and control information. 10. The electronic blackboard system according to claim 8, wherein the control information is for asynchronously transmitting predetermined identification information. 11. The electronic blackboard according to claim 8, wherein a conversion table for converting identification information unique to the electronic blackboard chip into predetermined individual data is provided on the electronic blackboard or a processing device for processing data of the electronic blackboard and is attached to the electronic blackboard. An electronic blackboard system characterized in that the unique identification information read from any electronic blackboard chip is converted into corresponding individual data by referring to the above table.