JP2520816B2 - Identification code data recognition method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transmitting a unique identification (ID) code signal when a mobile station approaches a fixed station and detects a signal from the fixed station. The present invention relates to a method of recognizing identification code data between a mobile station and a fixed station.

[0002]

2. Description of the Related Art For example, in order to allow only a specific person to enter and exit a specific entrance / exit, conventionally, an ID card as a mobile station having an identification code is issued and the ID
The card was directly inserted into the doorway or a card reader installed on the side of the door to read it, and it was judged whether the identification code was given only to the person who can enter the room, and if it matched, the door was opened. In this case, the operation is extremely troublesome, so it is conceivable that a wireless signal is transmitted from the ID card, and when it approaches the entrance, it is automatically sensed to determine the content of the identification code of the ID card. . In this case, when a digital signal from the ID card is demodulated by the fixed station, a filter is interposed, so that it is desired to be able to surely demodulate while narrowing the bandwidth of the signal as much as possible.

[0003]

However, in order to transmit a wireless signal, it is necessary to modulate the carrier wave with the identification code data. There is a pulse modulation method using a pulse as this carrier wave, and there is a PPM (pulse position). Modulation), P
WM (pulse width modulation) and the like are known. However,
A simple data recognition method such as that of the present invention, which is sufficient to recognize an identification code, requires a large number of bits regardless of which modulation method is used, PPM or PWM.
There are problems that the frequency band is widened and that the pulse width during transmission changes to cause noise and malfunction.

It is an object of the present invention to provide a method of recognizing identification code data that makes identification code data from a mobile station as simple as possible and that demodulates the received fixed station more reliably. Is.

[0005]

According to the present invention, when a mobile station receives a signal transmitted from a fixed station, the mobile station transmits identification code data specific to the mobile station read by a clock read signal based on the received signal. And this is a fixed station,
In the method for controlling a controlled device by determining whether or not it is registered, binary data of an identification code in the mobile station is composed of "010" and "10" (or "101" and "01"). Then, the reading timing T of the sampling signal for reading the digital data demodulated by the fixed station is t <T <2t (t is a unit reading of data in the mobile station) from the falling (or the rising) of the data. It is a method for recognizing identification code data, which is characterized by being set in the range of (time).

[0006]

The fixed station repeatedly transmits from the transmitting / receiving coil 50 at regular intervals. Assuming that the ID card A10 has entered the area where signals can be received by the fixed station 11, I
The coil of the D card A10 receives the signal A2 (resonance)
Then, a clock read signal of cycle t is output from the first frequency dividing circuit 65, and the signal divided by 64 is
The second frequency divider circuit 66 divides the frequency by 128 and outputs it as a reset signal. The clock read signal of the first frequency dividing circuit 65 is sent to the identification code generating circuit 67, and the data "1" of the identification code data in the mobile station is changed to "01".
Unique identification code data in which data "0" is composed of "10" is generated. The identification code data from the identification code generation circuit 67 modulates the oscillation signal of the fixed station.

The oscillation signal of the fixed station A11 modulated by the identification code signal A3 of the ID card A10 is demodulated into a digital signal and input to the microcomputer 54. In this microcomputer 54, when data is input, the timer of the data acquisition circuit 72 is turned on at the falling edge of this data, and the sampling signal is output after the elapse of the set time of the timer, that is, the read timing time T, at that time. Data of the above is input to the RAM 75. That is, the set time T of the timer is set to t <T <2t, specifically T≈1.5t, where t is the cycle of the clock read signal. Since the first 5 bits are included in the input data as a header, assuming that the demodulated signal is "1" 1.5t after the fall, the next is "0".
Therefore, “10”, that is, the data is determined to be “0”. Then, 1.5t from the falling edge of the next pulse
After that, if it is "0", "10" continues until the next sampling, so "010", that is, the data is determined to be "1". Similarly, for example, the data “010
"0" is output. This data "0100" is converted into a decimal output 4. Thereafter, a 4-digit signal is sequentially output.
The identification code input by the discrimination circuit 73 is R
It is determined whether it is registered in AM75.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is an overall block diagram showing the relationship between a fixed station and a mobile station (ID card), and shows a case where a plurality of fixed stations are centrally managed at one location. It goes without saying that the present invention can be applied to only one fixed station and one mobile station. Further, as the controlled machine, for example,
A case will be described as an example where a fixed station detects a mobile station (ID card) having a specific identification code and the door automatically opens and closes.

Doors 12, 22, 3 as the controlled machines
Stations A are directly connected to or near 2, ...
11, fixed station B21, fixed station N31, ... Are installed. These fixed stations A11, 21, 31, ... Are coupled in parallel to a fixed station centralized management circuit 40, and this fixed station centralized management circuit 40 is coupled to a control circuit 41. The management circuit 40 controls opening / closing of the doors 12, 22, 32, ... As the controlled machines. The mobile station ID card A10, ID card B20, ID card N30, ...
When it receives a transmission request signal from the fixed stations A11, 21, 31, ..., It transmits its own identification code.

The ID card 10 (same for 20, 30, ...) And the fixed station 11 (same for 21, 31, ...) Will be described in detail with reference to FIG. The fixed station 11 is
An oscillation circuit 55 that generates a high frequency signal at fixed time intervals, an LC resonance circuit 56 that forms a high frequency electromagnetic field in the space that is composed of a transmission / reception coil 50 and a capacitor 57, a tuning circuit 51 that extracts an envelope signal from the received signal, and a voltage. Amplifying circuit 52 for amplifying, waveform shaping circuit 5 for shaping the input signal waveform
3. Data storage, determination, and fixed station centralized control circuit 40
It comprises a microcomputer 54 for exchanging signals with the microcomputer 54, a ROM 74 and a RAM 75 coupled to the microcomputer 54, and the microcomputer 54 is provided with a data fetching circuit 72 and a discriminating circuit 73.

The ID card 10 comprises a coil 60 and a capacitor 62, an LC resonance circuit 63 that resonates with a high frequency electromagnetic field formed in space by the coil 50 of the fixed station 11, and a clock signal synchronized with the resonance frequency. A clock extraction circuit 61, a first frequency division circuit 65 that divides the extracted clock signal by 64 and outputs a clock read signal (cycle t), and an output of the first frequency division circuit 65
Second frequency divider circuit 6 that divides the frequency by 28 and outputs a reset signal
6. A self-specific identification code, for example, data “1” is set to “01” by the clock read signal of the first frequency dividing circuit 65.
It is composed of an identification code generating circuit 67 for outputting data "0" with "10" and a switch element 68 such as FET, and the frequency at both ends of the coil 50 of the fixed station 11 is AM according to the identification code. It comprises a modulation circuit 69 for modulating.

The operation of the above arrangement will be described with reference to the waveform chart of FIG. 2 and the flowchart of FIG. (1) When the fixed station central control circuit 40 is turned on, the reset pulse signals of A1, B1, and N1 are sequentially sent to the fixed stations 11, 21, and 31 in a time-divisional manner, and after all are sent, the fixed station 11 is again sent. A reset pulse signal is sent to, and this is repeated thereafter.

(2) The fixed stations 11 and 2 are reset by the reset pulses A1, B1 and N1 from the fixed station centralized control circuit 40.
The reference numerals 1 and 31 respectively form a high-frequency electromagnetic field in a space. In the following description, the exchange of signals between the fixed station 11 and the ID card 10 will be described. By the reset pulse A1 from the fixed station centralized control circuit 40, the oscillation circuit 55
When the high frequency signal oscillates from, the high frequency electromagnetic field as the receivable area is repeatedly formed from the coil 50 of the LC resonance circuit 56 at regular intervals.

(3) Assuming that the ID card 10 has entered the area where the fixed station 11 can receive the signal A2,
A clock signal that resonates in the LC resonance circuit 62 including the coil 60 and the capacitor 62 of the ID card 10 and is synchronized with the resonance frequency is extracted by the clock extraction circuit 61, and this is divided by the first frequency division circuit 65 by 64. As shown in FIG.
A clock read signal of cycle t is output, and this 6
The signal divided by 4 is divided by 128 in the second dividing circuit 66 and output as a reset signal as shown in FIG. 2B.

The clock read signal of the first frequency dividing circuit 65 is sent to the identification code generating circuit 67 via the inverter to generate unique identification code data as shown in FIG. 2 (c). The identification code data in this mobile station
“1” is composed of “010”, and “0” is composed of “10”. At this time, a check digit or the like (not shown) is added to the identification code data. When the clock read signal of the first frequency dividing circuit 65 outputs 128 clocks, a reset signal is output from the second frequency dividing circuit 66 and the operation returns to the beginning again. The identification code data from the identification code generation circuit 67 is used as the switching element 6 of the modulation circuit 69.
8 is turned on and off to change the impedance, and the frequencies at both ends of the coil 50 of the fixed station 11 are AM-modulated.

(4) The voltage change amount of the signal modulated as shown in FIG. 2D by the identification code signal of the ID card 10 is subjected to envelope detection demodulation by the tuning circuit 51, and the amplification circuit 52.
2 is used for voltage amplification, and the waveform is shaped by the waveform shaping circuit 53.
A digital signal as shown in (e) is input to the microcomputer 54. In the microcomputer 54, when the data is input, the timer of the data capturing circuit 72 is turned on at the falling edge of the data as shown in the flowchart of FIG. 3, and after the set time of the timer, that is, the read timing time T elapses, A sampling signal as shown in FIG. 2F is output, and the data at that time is input to the RAM 75. That is, the set time T of the timer is t <T <2, where t is a unit reading time of data in the ID card 10.
t, specifically, T≈1.5t. In this case, since the clock signal of the first frequency dividing circuit 65 is read every 1 cycle (τ) as shown in FIG. 2A, the unit reading time t = clock It becomes the period τ. However, when data is read every m cycles (mτ) of the clock signal, the unit read time t = mτ. Since the input data contains the first 5 bits as a header, the demodulated signal is, for example, in the case of FIG.
After that, it is "1" and the next is "0".
0 ", that is, the data is determined to be" 0 ". Then, 1.5t after the trailing edge of the next pulse, it is "0", and "10" continues until the next sampling.
It is determined that the data is "010", that is, the data is "1". Similarly, the data “0100” is output. This data "0100" is converted into a decimal output 4. Thereafter, a 4-digit signal is sequentially output. It is determined whether or not the identification code input by the discrimination circuit 73 is registered in the RAM 75.

(5) If registered, the fixed station number of the fixed station 11 is added to the identification code, and the microcomputer 54 outputs the signal A4 of FIG. 4 to the fixed station centralized control circuit 40.

(6) The data A4 input to the fixed station centralized control circuit 40 is converted into predetermined data and then the control circuit 41.
Is output to

(7) By the control signal from the control circuit 41, the door 12 as the controlled machine is controlled to be opened, and when the person carrying the ID card A10 passes by, the door 12 as the controlled machine is passed. To close.

The above description is for the ID card 10 and the fixed station 1.
1 has been described, the same applies to the relationship between the ID card 20 and the fixed station 21 and the relationship between the ID card 30 and the fixed station 31.

In the above embodiment, the data "1" of the identification code data in the mobile station is composed of "010",
The data "0" is composed of "10", and the read timing T of the sampling signal for reading the digital data demodulated by the fixed station is set as the falling edge of the data.
However, the present invention is not limited to this embodiment, and as shown in FIG. 2 (g), the data "1" of the identification code data in the mobile station is composed of "101" and the data "0". , "01", and the sampling signal read timing T for reading the digital data demodulated by the fixed station can be the rising edge of the data. Further, in the case of FIG. 2 (e), the rising is used as the reference, and in the case of FIG. 2 (g), the falling is used as the reference,
The timing T is in the range of 2t <T <3t.

[0022]

As described above, according to the present invention, the binary data of the identification code in the mobile station is set to "010" and "10".
(Or “101” and “01”), and the reading timing T of the sampling signal for reading the digital data demodulated by the fixed station is t <T <2t from the falling (or rising) of the data. Since the identification code data is recognized by setting the range of (t is the cycle of the clock read signal), the following effects are obtained. (1) Even if a filter is provided in the fixed station, while keeping the bandwidth of the digital signal from the ID card as narrow as possible,
You can certainly demodulate. (2) No noise even if the pulse width changes. (3) It is suitable for transmitting simple data such as an identification code. (4) Not only can the ID card be a battery-less type, but even if the ID card is a battery built-in type, the battery consumption is extremely small.

[Brief description of drawings]

FIG. 1 is a block diagram of an ID card A10 and a fixed station A11 as a mobile station for implementing the method of the present invention.

FIG. 2 is an output waveform diagram of each unit.

FIG. 3 is a flow chart of a method according to the present invention.

FIG. 4 is an overall block diagram for performing the method of the present invention.

[Explanation of symbols]

10 ... ID card A as mobile station, 11 ... Fixed station A,
12 ... Door as controlled machine, 20 ... I as mobile station
D card B, 21 ... Fixed station B, 22 ... Door as controlled device, 30 ... ID card N as mobile station, 31 ... Fixed station N, 32 ... Door as controlled device, 40 ... Centralized control of fixed station Circuit, 41 ... Control circuit, 50 ... Coil, 51 ... Tuning circuit, 52 ... Amplification circuit, 53 ... Waveform shaping circuit, 54 ... Microcomputer, 55 ... Oscillation circuit, 56 ... Modulation circuit, 67 ... Capacitor, 60 ... Coil, 61 ... Clock extraction circuit, 62
... Capacitor, 63 ... LC resonance circuit, 65 ... First frequency dividing circuit, 66 ... Second frequency dividing circuit, 67 ... Identification code generating circuit, 68 ... Switch element, 69 ... Modulation circuit, 72 ... Data acquisition circuit, 73 ... discrimination circuit, 74 ... ROM, 75
... RAM.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-3-52437 (JP, A) JP-A-63-312726 (JP, A) JP-A-54-814 (JP, A) JP-A-60- 101857 (JP, A) JP-A-48-95542 (JP, A)

Claims (2)

(57) [Claims] 1. A method of transmitting identification code data specific to a mobile station read by a read clock signal and recognizing the identification code data in a fixed station, wherein binary data of the identification code in the mobile station is "010" and "10". (Or "10
1 "and" 01 "), and the read timing T of the sampling signal for reading the digital data demodulated by the fixed station is set to the data fall (or
A method for recognizing identification code data, characterized in that it is set in a range of a predetermined time from a rise). 2. A sampling signal read timing T is set by a timer of a data acquisition circuit in the fixed station.
The identification code data recognition method according to claim 1, wherein the identification code data is set to ≈1.5t (t is a unit reading time of data in the mobile station).