JPH06257338A - Key and locking device using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a key with a novel structure that has high reliability and is simple for users, and a locking device using the key. [Structure] The key has a structure in which a metal body having a shape indicating the key information and the material is embedded in a non-conductive insulating material and formed in a flat plate shape. On the other hand, the locking device has a coil that allows the key to pass through the hollow portion, a self-excited oscillation circuit that generates an oscillation signal in cooperation with the coil, and a coil that is generated when the key passes through the hollow portion of the coil. Frequency detection circuit that detects changes in the frequency of the oscillation signal due to changes in the impedance and inductance of the coil due to the action of the eddy current generated in the metal body due to the magnetic field being generated, and a detection circuit that detects changes in the amplitude of the oscillation signal And a determination control circuit for determining the authenticity of the key by using the characteristic of the change between the frequency signal output from the frequency detection circuit and the amplitude signal output from the detection circuit as the key information of the metal body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key having a novel structure and a locking device for locking and unlocking with the key,
In particular, the present invention relates to a lock device that determines the key based on an electrical / magnetic principle.

[0002]

2. Description of the Related Art Conventionally, a locking device for locking and unlocking with a mechanical key having a key mountain has been generally used.
With the progress of electronic technology in recent years, a so-called magnetic detection type locking device that operates by decrypting key information magnetically recorded on a so-called magnetic card and an optical decryption of a bar code corresponding to the key information An optical reading type locking device or the like that operates has been developed, and a locking device having various functions has been developed in consideration of use and simplicity.

[0003]

However, in the above-described magnetic detection type locking device, the magnetic card equivalent to the key is recognized to be excellent in portability, but the magnetic recording for magnetically recording key information. Since the medium is easily damaged and it is easy to read by a commercially available card reader or imitate using a magnetic tape or the like, there is a problem in reliability. Further, since there is a case where the magnetic head incorporated in the locking device malfunctions due to the positioning accuracy, there is a problem that maintenance management becomes complicated.

In the above-mentioned optical reading type locking device, the bar code is liable to be adversely affected by dirt and the like, so that there is a problem in reliability, and further, there is a problem that it is abused because it is easily copied. .

The present invention has been made in view of such problems, and has a high reliability which is an original function,
Moreover, it is an object of the present invention to provide a key having a novel structure that can be conveniently used by a user and a locking device using the key.

[0006]

In order to achieve such an object, a novel key is to embed a metal body having a shape representing key information and material into an insulating material having non-conductivity and to form a flat plate shape. It is configured to be formed.

On the other hand, in the locking device, a coil that allows the key to pass through the hollow portion, a self-excited oscillating circuit that generates an oscillation signal in cooperation with the coil, and the key that passes through the hollow portion of the coil. Sometimes, a frequency detection circuit for detecting a change in frequency of the oscillation signal due to a change in impedance and inductance of the coil due to an action of an eddy current generated in the metal body by a magnetic field generated in the coil, The detection circuit for detecting the amplitude change of the oscillation signal, and the characteristic of the change between the frequency signal output from the frequency detection circuit and the amplitude signal output from the detection circuit are used as the key information of the metal body to verify the authenticity of the key. And a determination control circuit for determining.

[0008]

The above-mentioned key having such a structure is excellent in mechanical strength and can be formed into a lightweight, thin and small shape.

On the other hand, in the locking device, a self-excited oscillation circuit that generates an oscillation signal in cooperation with the coil magnetically detects the shape and material characteristics of the metal body embedded in the key,
At the same time, an oscillation signal having a frequency and amplitude corresponding to these shapes and materials is output. Therefore, the determination control circuit determines the type and authenticity of the key by collating the change in the frequency and the amplitude as the characteristic parameter with the reference characteristic data stored in the storage memory in advance.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the structure of a detection sensor 2 for detecting the inserted key 1. First key 1
Is a card-shaped flat body having a length and width of several centimeters to ten and several centimeters and a thickness of several millimeters,
It has a structure in which a metal plate 3 having a predetermined shape and material representing key information is integrally molded with non-transparent plastic. Therefore, the metal plate 3 is fixedly embedded so that it cannot be seen from the outside.

Next, the detection sensor 2 includes a base 4 formed of an insulating material such as plastic, a coil 5 provided on the base 4, and a core for preventing the coil 5 from being affected by external magnetism. It has 6 and 7. Here, a slit-shaped hollow hole 4a for inserting the card-shaped key 1 is formed in the base body 4, and flange portions that are orthogonal to the insertion direction of the key 1 and face each other at a predetermined interval W. 4b,
4c is formed integrally with the outer wall. The coil 5 is formed by winding the wire between the flange portions 4b and 4c, and the core 6 is formed on the flange portions 4b and 4c.
The coil 5 is covered by tightly fitting the coil 7. For convenience of explanation, FIG. 1 shows a state in which the core 7 is removed from the flange portions 4b and 4c.

Next, the circuit configuration of the electric circuit to which the detection sensor 2 is connected will be described with reference to FIG. The electric circuit includes a feature extraction circuit 8 that extracts feature information of the shape and material of the metal plate 3 when the key 1 is inserted into the hollow portion 4a.
A determination control circuit 9 for identifying the shape and material of the metal plate 3 from the characteristic information and determining the authenticity of the key 1 based on the identification result.

First, the feature extraction circuit 8 includes capacitors C1 and C connected in series to both ends 5a and 5b of the coil 5, respectively.
In addition, the coil 5 has one end 5b connected to a predetermined voltage source V _EE and the other end 5a connected to the non-inverting input contact of the comparator 10. The comparator 10 operates with a predetermined power source voltage V _DD and power supplied from ground, its inverting input contact is connected to the voltage source V _EE , and its output contact is a load resistor R.
It is connected to a predetermined voltage power supply V _CC1 via L and to a common connection contact P of the capacitors C1 and C2 via a feedback resistor Rf.

Here, the circuit composed of the comparator 10, the resistors RL and Rf, the capacitors C1 and C2, and the coil 5 constitutes a Colpitts type self-excited oscillator.
An oscillating signal Q having a frequency and an amplitude determined by the circuit constant of a tuning circuit composed of C2 and the coil 5 is generated at the non-inverting input terminal of the comparator 10, and a magnetic field having a magnetic flux density corresponding to the cross current flowing in the coil 5 is generated. Occur. Since this magnetic field is generated in the hollow hole 4a in FIG. 1, the key 1 is inserted into the hollow hole 4a to pass through this magnetic field.

Here, when the metal body 3 of the key 1 passes through the magnetic field of the coil 5, the inductance and impedance of the coil 5 change under the influence of the eddy current generated in the metal body 3, and the coil 5 and the capacitor C1. , C2 changes the circuit constant of the tuning circuit, so that the amplitude and frequency of the oscillation signal Q change. The inductance (L) of the coil 5 theoretically changes according to the relationship of the following equation.

[0017]

[Equation 1]

The amplitude of the oscillation signal Q is proportional to the cross-sectional area of the portion affected by the magnetic flux when the metal body 3 traverses the magnetic field, and the larger the cross-sectional area, the smaller the amplitude. Is a specific frequency according to the material (magnetic permeability) of the metal body 3. Further, if the metal body 3 is a material having a magnetic permeability higher than that of air, the frequency becomes lower as the cross-sectional area increases, and conversely, if the metal body 3 is a material having a magnetic permeability lower than that of air, The larger the cross-sectional area, the higher the frequency.

The oscillation signal Q generated in this way is
It is constantly input to the frequency detection circuit 11 and the detection circuit 12, the frequency detection circuit 11 detects a frequency change of the oscillation signal Q and outputs frequency data Df indicating the frequency, and the detection circuit 12 outputs the envelope amplitude of the oscillation signal Q. Is detected and amplitude data Dh indicating its amplitude is output. Then, these data Df and Dh are supplied to the determination control circuit 9 having an arithmetic function such as a microprocessor. The frequency detection circuit 1
A known frequency discrimination circuit for detecting the frequency of the crossover signal can be applied to 1, and a known detection circuit such as a diode detection circuit for detecting the envelope amplitude of the crossover signal can be applied to the detection circuit 12. The determination control circuit 9 has a built-in A / D converter and has frequency data Df and amplitude data Dh.
Is digitally processed as a digital data to identify the characteristics of the shape and material of the metal body 3 based on the data Df and Dh, and the result of the identification is stored in a storage memory built in the determination control circuit 9 in advance. The authenticity of the key 1 is determined by collating the reference characteristic data stored in.

Further, the output of the judgment control circuit 9 is connected with an actuator M in a locking mechanism 13 for performing a locking (locking) and an unlocking (unlocking) operation via a drive power supply circuit, and A display means 14 is connected to display whether the locking mechanism 13 is in a locked state or an unlocked state, and to display a warning when a regular key is not inserted. In this embodiment, the display means 14 is a liquid crystal display provided on a display panel mounted on a door or the like.

Next, the operation of the locking device having the above construction will be described with reference to FIGS. 3 and 4. First, in FIG. 3, in order to clarify the principle of the present invention, a case where the metal body 3 embedded in the key 1 is circular, which is the most basic shape, will be described. Therefore, when the key 1 is inserted into the hollow hole 4a of the detection sensor 2, as shown in FIG. 3A, the circular metal body 3 passes through the hollow portion of the coil 5 along the direction A. To do.

When the metal body 3 is not inserted into the hollow portion of the coil 5 as before a certain time t1, the inductance of the coil 5 is uniquely determined when the metal body 3 is not affected by the magnetic field. An oscillation signal Q having a constant frequency and amplitude is generated [see FIG. 3 (b)]. Along with this, the amplitude data Dh output from the detection circuit 12 has a constant amplitude H0.
[See FIG. 3C] The frequency data Df output from the frequency detection circuit 11 also has a constant frequency [see FIG. 3D].

Next, as shown at a certain time t2, when the tip portion of the metal body 3 reaches the tip portion of the coil 5, an eddy current is generated in the tip portion due to the influence of the magnetic field, and at the same time, the inductance and the inductance of the coil 5 are increased. The Impedus has changed,
The frequency and amplitude of the oscillation signal Q start to change. here,
When the magnetic permeability of the metal body 3 is higher than that of air, the amplitude of the amplitude data Dh decreases and the frequency data D
The frequency of f also decreases. Further, as the metal body 3 advances into the hollow portion of the coil 5, the generation of the eddy current gradually increases, and the frequency and the amplitude of the oscillation signal Q change in accordance with the change.
The amplitude of the amplitude data Dh and the frequency of the frequency data Df change.

Then, as shown at time t3, the metal body 3
When the central part of the coil coincides with the central part of the coil 5, the eddy current generated in the metal body 3 becomes maximum, and the amplitude of the oscillation signal Q and the amplitude data Dh is the bottom value H1 as shown in the figure.
At the same time, the frequency of the frequency data Df becomes the lowest.

Next, when the metal body 3 is gradually disengaged from the coil 5 during the time t3 to t4, the oscillation signal Q,
The amplitude data Dh and the frequency data Df are restored to the original state.

Then, as shown at time t4, the metal body 3
When the rear end of the coil 5 overlaps with the rear end of the coil 5, the oscillation signal Q
And the amplitude H2 of the amplitude data Dh approaches H0, and at the same time,
The oscillation signal Q and the frequency data Df also have the same frequency as at the time point t2.

Next, when the metal body 3 is completely removed from the coil 5 at time t5, the influence of the magnetic field is eliminated, so that the oscillation signal Q, the amplitude data Dh and the frequency data Df are obtained.
Is at time t1.

As described above, the amplitude data Dh and the frequency data Df show with high accuracy the characteristics of the shape (in particular, the cross-sectional area and diameter) and the material of the metal body 3. Then, the determination control circuit 9
Determines that the true key 1 has been inserted when the changes in the amplitude data Dh and the frequency data Df match the previously registered reference characteristic data. If the locking mechanism is in the locked state before the key 1 is inserted, the actuator M is instructed to perform the unlocking operation and the display means 14 displays a message indicating that the unlocking operation is being performed. , On the contrary, key 1
If the locking mechanism is in the unlocked state before is inserted, the actuator M is instructed to perform the locking operation, and the display means 14 displays a message indicating that the locking operation is being performed.

Further, although the metal body 3 having the most basic shape has been described as an example in FIG. 3, as shown in FIG.
The key 1 to which the metal body 3 having a more complicated shape is applied is the coil 5
The operation when it is inserted into
As shown in (b) and (c), before the metal body 3 is inserted into the coil 5, at t6, the amplitude data Dh and the frequency data Df have constant amplitude and frequency. Then, as the first peak portion 3a of the metal body 3 gradually passes through the coil 5, the amplitude of the amplitude data Dh and the frequency data D
When the frequency of f changes and the cross-sectional area of the crest portion 3a that crosses the coil 5 becomes maximum, a trough portion having the lowest amplitude and frequency is generated at t7. Further, the second mountain portion 3 of the metal body 3
When b passes through the coil 5, the values of the amplitude data Dh and the frequency data Df change according to the cross-sectional area of the coil 5, and when the cross-sectional area of the peak portion 3b crossing the coil 5 becomes maximum, the valley portion as illustrated at t8. Occurs. Furthermore, the third mountain portion 3 of the metal body 3
When c passes through the coil 5, the values of the amplitude data Dh and the frequency data Df change according to the cross-sectional area of the coil 5, and when the cross-sectional area of the crest 3c that crosses the coil 5 becomes maximum, the trough as illustrated at t9. Occurs. Furthermore, the fourth mountain portion 3 of the metal body 3
When d passes through the coil 5, the values of the amplitude data Dh and the frequency data Df change according to the cross-sectional area of the coil 5, and when the cross-sectional area of the crest 3d crossing the coil 5 becomes maximum, the trough as shown in FIG. Occurs.

As described above, even if the metal body 3 having a complicated shape is applied, the characteristics of the shape and the material can be detected with high accuracy. Therefore, by using the metal body 3 having a complicated shape, complicated key information can be obtained. The key 1 can be realized, and copying and forgery can be prevented.

Further, according to this embodiment, it is possible to provide a key having excellent mechanical strength, and it is also possible to provide a highly accurate locking device having an extremely simple structure. In addition, this key can provide convenience to the user, and, in combination with the use of this key, a highly reliable locking device can be provided.

Next, another embodiment will be described with reference to FIG.
In FIG. 5, the same or corresponding parts as in FIG. 1 are designated by the same reference numerals.

First, the key 1 used in this embodiment has a card-like shape in which a metal body 3 having a shape representing the key information is integrated by plastic molding, as in the case shown in FIG. The feature of this embodiment is that a plurality of sets of flange portions 4b ₁ and 4c facing each other at predetermined intervals are provided on the outer wall of a plastic base body 4 in which a hollow hole for inserting the key 1 is formed.
_{1 ~4b n,} 4c _n are integrally formed, n pieces of coils 5 ₁ to 5 _n is wound between each pair of flanges. Further, each of the coils 5 _{1 to} 5 _n has a characteristic extraction circuit 8 shown in FIG.
It is connected to the n-number of feature extraction circuit 8 ₁ to 8 _n equal configuration when all amplitude data Dh ₁ ~Dh _n and frequency data Df ₁ ~Df _n is outputted from the feature extraction circuits 8 ₁ to 8 _n It is supplied to the determination control circuit 9, and the lock mechanism 13 and the display means 14 are connected to the output of the determination control circuit 9.

The locking device having the above-mentioned structure has the coils 5 _{1 to} 5 _n and the feature extracting circuits 8 ₁ to 8 _n, which are in a connection relationship, _{respectively.}
Is substantially equivalent to the provision of n circuits shown in FIG. Therefore, independent magnetic fields are generated from the respective coils 5 _{1 to} 5 _n, and the metal body 3 of the key 1 passes through these magnetic fields. Since the impedance and the inductance of the coils 5 _{1 to} 5 _n change due to the eddy current generated in the metal body 3 when the metal body 3 passes through each magnetic field, the respective amplitude data Dh _{1 to} Dh _n The frequency data Df _{1 to} Df _n are shown in FIG.
Similar to the above, the shape and material characteristics of the metal body 3 change.

The judgment control circuit 9 uses these amplitude data D
By programming process changes in h ₁ ~Dh _n and frequency data Df ₁ ~Df _n, identify the shape and material of the metal body 3, further the identification result, characteristics of the reference that is previously registered in the storage memory If it matches the data, it is determined that the true key 1 has been inserted. If the locking mechanism is in the locked state before the key 1 is inserted, the actuator M is instructed to perform the unlocking operation and the display means 14 displays a message indicating that the unlocking operation is being performed. , On the contrary, key 1
If the locking mechanism is in the unlocked state before is inserted, the actuator M is instructed to perform the locking operation, and the display means 14 displays a message indicating that the locking operation is being performed.

As described above, according to this embodiment, since the shape and material characteristics of the metal body 3 are detected by using the plurality of coils 5 _{1 to} 5 _n , the metal body 3 can be identified with higher accuracy. Is possible. Furthermore, by changing / adjusting the widths and the arrangement intervals of the coils 5 _{1 to} 5 _n , it is possible to detect the main part of each part of the metal body 3 with particularly high accuracy and to position the convex / concave positions indicating the key information. It is possible to make a higher-level judgment such as judging the authenticity of the key 1 from the relationship.

Next, still another embodiment will be described with reference to FIGS. 6 and 7. 2 and 5 in these figures.
The same parts as or corresponding parts are indicated by the same reference numerals. First,
The difference from the locking device shown in FIG.
The n coils 5 _{1 to} 5 _n wound around each of the flanges 4 b ₁ and 4 c _{1 to} 4 b _n and 4 c respectively correspond to single wire rods.
It is constructed by continuously winding for _n times.
That is, all the coils 5 _{1 to} 5 _n are electrically connected in series, and the tips of the _first and _nth coils 5 ₁ and 5 _n have the same characteristics as those of the feature extraction circuit 8 shown in FIG. It is connected to the extraction circuit. Therefore, this embodiment has the circuit configuration shown in FIG.

In the locking device having such a structure,
When the key 1 is not inserted, the impedance and inductance of the coils 5 _{1 to} 5 _n and the capacitors C 1 and C 2
The frequency and amplitude of the oscillation signal Q are determined by the circuit constants determined by the capacitance of On the other hand, when the metal body 3 in the key 1 progresses gradually in these coils 5 ₁ to 5 _n, coil 5 ₁ to 5 due to the eddy current generated in the metal body 3 due to the influence of the magnetic field of the respective _Since the impedance and the inductance of _n change, the amplitude and frequency of the oscillation signal Q change according to the shape and material of the metal body 3. And this oscillation signal Q
Frequency data Df representing information on the amplitude change and frequency change of
And the amplitude data Dh are the frequency detection circuit 11 and the detection circuit 12
And the decision control circuit 9 outputs these data D
By identifying the shape and material of the metal body 3 based on f and Dh, and further comparing the identification result with the reference feature data stored in the storage memory in the determination control circuit 9,
Determine the authenticity of key 1. Then, the locking mechanism 13 and the display means 14 are controlled based on the determination result.

As described above, according to this embodiment, the characteristics of the shape and the material of the metal body 3 can be detected by the coils 5 _{1 to} 5 _n electrically connected. Further, since the detection processing is performed by one feature extraction circuit, the circuit scale can be reduced and the circuit can be easily adjusted as compared with the case of using the plurality of feature extraction circuits shown in FIG. And so on.

In the embodiments described with reference to FIGS. 1 to 7, the rectangular key 1 has been described, but the present invention is not limited to this, and may be arbitrarily selected according to the application. Can be in the shape of.

The metal body 3 embedded in the key 1 is not limited to a single metal material, and each portion of the metal body 3 may be formed of different kinds of metal materials.
Since the key information can be extracted from the above-mentioned frequency data Df by using a plurality of kinds of metal materials, it is possible to realize a higher and more reliable key and a locking device using the key.

Further, since the amplitude of the above-mentioned oscillation signal Q changes depending on the cross-sectional area when the metal body 3 crosses the magnetic field, not only the side surface of the metal body 3 is uneven, but also the thickness is uneven. It may be shaped.

Further, a shape having an annular portion may be formed by forming a hole in any portion of the metal body 3.

As described above, since the key information can be specified by the shape and material of the key, an extremely complicated key including a large amount of information can be realized, and further, in combination with the locking device. It is possible to realize a system having a high crime prevention function.

[0045]

As described above, according to the present invention, first, a novel key is formed by embedding a metal body having a shape and a material for expressing key information in an insulating material having non-conductivity and forming a flat plate shape. With such a structure, it is possible to realize a key that is excellent in mechanical strength, light in weight, thin, and small, and provides convenience to the user. Furthermore, since a key that is extremely complicated and contains a large amount of information can be realized, it is possible to provide a key having an excellent crime prevention function that can prevent duplication and forgery.

On the other hand, in the locking device, the self-excited oscillation circuit for generating an oscillation signal in cooperation with the coil magnetically detects the shape and material characteristics of the metal body embedded in the key, and at the same time, these Output an oscillation signal having a frequency and amplitude corresponding to the shape and material, and the determination control circuit determines the type and authenticity of the key using the change in the frequency and amplitude as the characteristic parameters. Information can be detected with high accuracy. Therefore, in combination with the novel key of the present invention, it exerts an excellent function when realizing a system having a high crime prevention function.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing a structure of a key and a detection sensor according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing an overall configuration of a locking device according to an embodiment.

FIG. 3 is an explanatory diagram for explaining the operation principle of the locking device according to the embodiment.

FIG. 4 is an explanatory diagram for further explaining the operation of the locking device according to the embodiment.

FIG. 5 is a configuration explanatory view showing a configuration of a locking device according to another embodiment.

FIG. 6 is a structural explanatory view showing the structure of a locking device according to still another embodiment.

FIG. 7 is a circuit diagram showing a configuration of a locking device according to still another embodiment.

[Explanation of symbols]

1 ... Key, 2 ... Detection sensor, 3 ... Metal body, 4 ... Substrate, 4a
... hollow _{hole, 4b, 4c, 4b 1,} 4c 1 ~4b n, 4c
_n ... flange, 5,5 ₁ to 5 _n ... coil, 6 ... core, 8, 8 ₁ to 8 _n ... feature extraction circuit, 9 ... judgment control circuit, 10 ... comparator, 11 ... frequency detecting circuit, 12 ... Detection circuit, 13 ... Locking mechanism, 14 ... Display means, C1, C2 ...
Capacitor, RL, Rf ... Resistance, M ... Actuator.

Claims (2)

[Claims] 1. A key characterized in that a metal body having a shape and a material representing key information is embedded in a non-conductive insulating material and formed into a flat plate shape. 2. A coil for passing a key formed by embedding a metal body having a shape and material representing key information in an insulating material having non-conductivity and formed into a flat plate into a hollow portion, and the coil. A self-excited oscillating circuit that generates an oscillating signal by cooperation, and an eddy current generated in the metal body by the magnetic field generated in the coil when the key passes through the hollow portion of the coil, by the action of the coil. A frequency detection circuit that detects changes in the frequency of the oscillation signal due to changes in impedance and inductance, a detection circuit that detects changes in the amplitude of the oscillation signal, a frequency signal output from the frequency detection circuit, and the detection signal. A lock control device, comprising: a determination control circuit that determines the authenticity of a key by using the characteristic of a change with an amplitude signal output from the circuit as key information of the metal body.