JP2000220331A - Optical key device - Google Patents

Abstract

(57) [Summary] [Object] To obtain an optical key device which is not worn or deteriorated by use and is hard to be copied by a third party. A key having an optical thin film having a spectral transmission characteristic that is not uniform with respect to wavelength; storage means for storing the spectral transmission characteristic of the optical thin film; and measuring a spectral transmission characteristic of a light beam transmitted through the optical thin film of the key. An optical key device comprising: a sensor; and a determination unit that compares a spectral transmission characteristic detected by the sensor with a spectral transmission characteristic stored in a storage unit and emits a predetermined electric signal when they match.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an optical key device.

[0002]

2. Description of the Related Art In a conventional key device, a key is properly contacted by physically contacting a key with a key cylinder in a keyhole, or electrically connecting a key to an electric contact to read a combination thereof. Or not. However, in such a structure in which the key and the determination unit are in contact with each other, as the number of times of use increases, abrasion and deterioration of conductivity are inevitable. Also, copying by a third party was easy.
On the other hand, a key device of a type in which a key does not contact a determination unit has also been proposed. For example, a key is formed with a shape to serve as a determination standard such as a punch hole or a notch, and the shape is read by irradiating light. There is something. However, since this type determines the physical shape of the key, there is a high possibility that it is copied to a third party.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide an optical key device which does not cause wear or deterioration due to use and which is difficult to be copied by a third party. .

[0004]

SUMMARY OF THE INVENTION An optical key device according to the present invention includes a key having an optical thin film having a spectral transmission characteristic that is not uniform with respect to wavelength; storage means for storing the spectral transmission characteristic of the optical thin film;
A sensor for measuring a spectral transmission characteristic of a light beam transmitted through the optical thin film of the key; and a predetermined electric signal when the spectral transmission characteristic detected by the sensor is compared with the spectral transmission characteristic stored in the storage means and matched. Determination means for issuing;
It is characterized by having. Since the optical key device having this configuration optically reads and determines the spectral transmission characteristics (wavelength dependence of light transmittance) of the optical thin film, wear and deterioration due to contact of the determination portion do not occur. Also, the transmission characteristic of the optical thin film is used for the determination, which cannot be identified from the appearance, and is difficult to be copied by a third party.

[0005] The light transmitted through the optical thin film is preferably white light.

The above-mentioned sensor includes a spectroscopic optical system for decomposing a light beam transmitted through an optical thin film into a spectrum; a light receiving element to which a spectrum from the spectral optical system is incident; an incident position of a light component on the light receiving element; Based on light intensity
Data generating means for generating spectral data of the light beam transmitted through the optical thin film; comparing the spectral data of the light transmitted through the thin film generated by the data generating means with the spectral data of the light beam not transmitted through the optical thin film Specifying means for specifying the spectral transmission characteristics of the optical thin film. At this time, it is preferable that the storage unit further stores spectral data of a light flux when the light flux is not transmitted through the optical thin film.

In the optical key device of the present invention, it is also possible that the storage means stores two or more different spectral transmission characteristics. In this case, this can be achieved by providing a plurality of keys corresponding to a plurality of spectral transmission characteristics stored in the storage means. Alternatively, providing a key support structure capable of changing the angle of the optical thin film with respect to the optical axis of the light beam incident on the optical thin film, and changing the angle of the optical thin film with respect to the incident optical axis by the key support structure Thus, it is also possible to configure so that different spectral transmission characteristics are measured by the sensor.

[0008] The predetermined electric signal generated by the determination means is preferably an unlock signal of a lock device.

[0009]

1 and 2 show an embodiment of an optical key device according to the present invention. This optical key device includes an optical key 11 and a key determination unit 20 into which the optical key 11 is to be inserted.

First, the optical key 11 will be described. The optical key 11 has a substrate portion 14 inserted into the grip portion 13 and the key determination portion 20, and the substrate portion 14 is formed of a material that does not transmit light. An opening 15 is formed substantially at the center of the substrate portion 14, and an optical thin film 16 is provided in the opening 15. As shown in the following Table 1, the optical thin film 16 in this embodiment is formed by alternately stacking a TiO ₂ layer and a SiO ₂ layer up to a seventeenth layer on a glass substrate (BK7) by a known thin film forming technique. I have. In Table 1, the fourth to fifteenth layers are omitted, but the odd-numbered layers are TiO ₂ layers and the even-numbered layers are SiO ₂ layers. As shown in the graph of FIG. 3, the optical thin film 16 thus formed has a spectral transmission characteristic that is not uniform with respect to wavelength (the light transmittance has wavelength dependence). Note that the spectral transmission characteristics referred to here are values obtained by continuously converting the light transmittance of a light-transmitting member such as an optical thin film for each wavelength into data. For example, a transmittance having no wavelength dependency with respect to the light transmittance. If it is an optical member, it will have uniform spectral transmission characteristics. The operation of the optical thin film 16 will be described later.

[0011]

The key determination section 20 has an insertion hole 21 into which the optical key 11 is inserted. A white light source 22 is provided above the insertion hole 21 in the key determination unit 20,
A visible light transmitting filter 23 is provided between the white light source 22 and the insertion hole 21. The visible light transmission filter 23 is
Of the white light emitted from the white light source 22, the visible region (wavelength 4
This filter transmits only light having a wavelength of from 00 nm to 700 nm, and the visible light reaches near the insertion hole 21.

When the optical key 11 is inserted into the insertion hole 21, the surface of the substrate portion 14, that is, the optical thin film 1 is removed.
6 is supported by a support member (not shown) so that the plane direction of the light source 6 is orthogonal to the optical axis O of the light beam from the white light source 22.

A slit 2 is provided on the optical path below the insertion hole 21.
4 is formed, and the light flux passing through the visible light transmission filter 23 is narrowed down by the slit 24, and then the concave diffraction grating 2 is formed.
Reaches 5. The light that has exited the slit 24 is diffracted by a concave diffraction grating 25 having a reflecting function, and only the first-order diffracted light is irradiated on the CCD 26 as a spectrum in the order of wavelength. The CCD 26 is a line sensor, and is installed so that the longitudinal direction thereof is oriented in the narrowing direction of the light narrowed by the slit 24 (the direction corresponding to the short direction of the slit 24). In the optical system of the present embodiment, This C
On the light incident surface of the CD 26, light of a longer wavelength is incident on the lower side in FIG. 2, and light of a shorter wavelength is incident on the upper side.

A light intensity detecting element having a predetermined geometric shape is provided on the CCD 26, and the light intensity in a predetermined wavelength region of the incident spectrum is determined at a resolution corresponding to the arrangement shape of the light intensity detecting element. Can be detected. That is, CC
Since light of different wavelengths enters D26 at different positions, spectral light intensity data can be obtained by monitoring the light incident position on the CCD 26 and the light intensity. The input interface 27 is a CCD 26
When light is incident on the CPU, the position of the light intensity detecting element and the detected intensity are converted so as to be readable by the CPU, and based on this, the CPU can obtain light intensity data of a spectrum.

The CPU 28 includes a memory unit 29 from which data can be read and written, and an output interface 30.
Connected to The output interface 30 determines that the optical key 11 is appropriate by a method described later.
When the determination is made in U28, an electrical signal for unlocking is transmitted to the electromagnetic lock 31 in response to the determination.

The above optical key device is prepared and used as follows. In the present embodiment, the lock operation of the electromagnetic lock 31 is performed by an external mechanical operation.

First, the white light source 22 emits light without inserting the optical key 11 into the insertion hole 21. Then, the light flux (visible light passing through the visible light transmission filter 23) from the white light source 22 is narrowed down by the slit 24, and the concave diffraction grating 2
The first-order diffracted light is irradiated on the CCD 26 in order of wavelength. At this time, the spectrum data detected via the CCD 26 represents the characteristics of the optical system of the key determination unit 20 in a state where the optical thin film 16 of the optical key 11 does not pass through. In the memory M1 of the memory unit 29. Further, in the memory M3, effective key data representing the spectral transmission characteristics of the optical thin film required for unlocking is recorded. Memory M
1. Recording of each data in M3 may be performed at the stage of manufacturing the device.

To unlock the electromagnetic lock 31,
The optical key 11 is inserted into the insertion hole 21. As described above, the optical key 11 includes the optical thin film 16 having a spectral transmission characteristic that is not uniform with respect to the wavelength.
Is inserted, the optical thin film 16 is located on the optical path between the white light source 22 (visible light transmitting filter 23) and the slit 24. Therefore, when the light beam from the white light source 22 passes through the optical thin film 16, the spectrum of the transmitted light changes according to the spectral transmission characteristics of the optical thin film 16.

The light transmitted through the optical thin film 16 of the optical key 11 is narrowed down by a slit 24, diffracted by a concave diffraction grating 25, and irradiated on a CCD 26 in order of wavelength. CCD26
Since a spectrum changed by passing through the optical thin film 16 is incident on the upper portion, if this is converted into data, a spectrum data value different from the white light source data previously stored in the memory M1 is obtained. This spectrum data value is stored in the memory M2 as optical key data.

Subsequently, the CPU 28 executes a process for removing the difference between the spectrum data value of the memory M2 and the spectrum data value of the memory M1. Then, a substantial change in the spectrum due to the influence of the optical thin film 16, that is, the spectral transmission characteristic of the optical thin film 16 is specified.

The degree of coincidence is statistically calculated by the CPU 28 as to whether or not the spectral transmission characteristics of the optical thin film 16 specified in this manner match the valid key data stored in the memory M3. If the degree of coincidence between the two data values is equal to or greater than the predetermined value, the CPU 28 outputs a determination that the optical key 11 is appropriate, and the output interface 30 transmits an unlocking electric signal in response to the determination. The lock is supplied to the lock 31, and the lock is released. On the other hand, if the degree of coincidence between the key data generated through the same processing as described above and the valid key data in the memory M3 is less than the predetermined value, the lock release operation is not performed. It should be noted that the degree of matching is valid at any time, but naturally, the higher the degree of matching between the inserted key data and the previously stored valid key data, the higher the determination accuracy, This makes it difficult to duplicate the key by the key device. In the present apparatus, such criteria for determining the degree of coincidence can be set and adjusted by software.

As described above, the optical key device of the present invention does not determine a key by a combination of a physical contact shape or a combination of electrical continuity unlike the conventional device, but a spectral transmission characteristic of an optical thin film, that is, a key. Since the wavelength dependence of the light transmittance is read, wear and deterioration due to contact between the key and the key determination unit do not occur in principle. In addition, the light transmission characteristics of the optical thin film cannot be identified from the appearance, and a nearly infinite pattern can be created by applying a well-known thin film technology. Also, by changing the spectral transmission characteristic data of the optical thin film stored in the key determination unit, it is possible to cope with various key patterns without changing the mechanical configuration. A new key can be easily handled.

FIGS. 4 to 6 show different embodiments. Constituent members common to the previous embodiment are denoted by the same reference numerals, and detailed description is omitted. In this embodiment, the optical key 11 is the same as the previous embodiment,
Are common. On the other hand, the key determination unit 120
As shown in FIG. 5 and FIG. 5, the angular position (solid line) where the plane direction of the optical thin film 16 is orthogonal to the incident optical axis O, and the gripper 1
It is possible to rotate and hold the optical key 11 at an angular position (two-dot chain line) tilted about 30 degrees from the axis 3 around the axis, and to set the optical key 11 at each angular position.
By holding the optical thin film 16 with respect to the optical axis O.
Can be positioned at different angles. That is, the angle of incidence of the light beam on the optical thin film 16 can be relatively changed. Hereinafter, the former holding angle of the optical key 11 (the optical thin film 16 is orthogonal to the optical axis O) is θ1, and the latter holding angle (the optical thin film 16 is inclined by about 30 degrees) is θ2.

When the optical key 11 is at the angle θ1, the plane direction of the optical thin film 16 is orthogonal to the optical axis O.
With regard to 6, the same spectral transmission characteristics (see FIG. 3) as in the previous embodiment are obtained. FIG. 6 shows the spectral transmission characteristics of the optical thin film 16 when the optical key 11 is at the angle θ2. At this angular position of the optical key 11, since the incident angle of the light beam on the optical thin film 16 changes, it can be read that the spectral transmission characteristics are different from those shown in FIG.

The optical key device of this embodiment is used as follows. First, similarly to the previous embodiment, the optical thin film 1
The spectrum data value in a state where the light does not pass through 6 is stored in the memory M1 of the memory unit 29 as white light source data. Further, the memory M31 stores effective key data θ1 representing the spectral transmission characteristics of the optical thin film at the angle θ1,
The memory M32 stores effective key data θ2 representing the spectral transmission characteristics of the optical thin film at the angle θ2.

At the time of unlocking, the optical key 11 is inserted into the key judging section 120 and, for example, is initially held at the position of the angle θ1. Then, as described above, the spectrum of the light changes as it passes through the optical thin film 16, and the light is separated by the concave diffraction grating 25 and detected by the CCD 26 to be converted into data. This spectral data value is stored in the optical key 11
Memory M as optical key data θ1 at the angle θ1
21 is recorded. The CPU 28 specifies the substantial spectral change when the optical key 11 is inserted at the angle θ1, that is, the spectral transmission characteristic of the optical thin film 16, from the spectral data values of the memories M1 and M21 by the above-described method. The effective key data θ1 to be compared with the specified spectral transmission characteristics is stored in the memory M31, and the CPU 28 determines the degree of coincidence between the spectral transmission characteristics of the optical thin film 16 and the effective key data θ1. If the degree of coincidence is equal to or greater than a predetermined value, the determination is held by the CPU 28. At this point, no lock release operation occurs.

Subsequently, the optical key 11 inserted into the key determination section 120 is rotated to the angle θ2. As a result, the optical thin film 16 gives a change in the spectrum of the transmitted light different from that at the angle θ1, and as a result, the CPU 28
Is different from that at the time of the insertion of the angle θ1. This data value is recorded in the memory M22 as optical key data θ2 at the angle θ2,
By comparing with the white light source data stored in the memory M1,
The spectral transmission characteristics of the optical thin film 16 at the angle θ2 are specified. The specified spectral transmission characteristics are obtained by the CPU 28.
The degree of coincidence with the valid key data θ2 stored in the memory M32 is determined. As a result, if the degree of coincidence is equal to or larger than the predetermined value, it is determined that the spectral transmission characteristic of the optical thin film 16 is appropriate at any of the angles θ1 and θ2, that is, the optical key 11 is appropriate. Is output to In response to this, the output interface 30 sends an electric signal for unlocking to the electromagnetic lock 31, and the unlock operation is performed.

As described above, by judging the validity (spectral transmission characteristics of the optical thin film) of the key at a plurality of rotation angle positions in a complex manner, the number of keys is not increased, the judgment accuracy is high, and copying is difficult. A device can be obtained. In this embodiment, the angle position of the optical key 11 is set to two positions. However, a configuration in which the determination is performed in a composite manner at three or more angle positions is also possible. Also in the present embodiment, the level of the matching degree at the time of determination can be set and adjusted by software.

In the above description, the optical key 11 is rotated in the key determination unit 120.
Two insertion holes corresponding to θ2 may be provided, and the optical key 11 may be removed from one insertion hole and then inserted into the other insertion hole.

The present invention is not limited to the above embodiments. For example, in each embodiment, the spectral optical element is a diffraction grating, but a similar effect can be obtained by using a prism instead of the diffraction grating.

The operation to be performed in accordance with the determination of the optical key is not limited to the unlocking operation of the electromagnetic lock. For example,
Although only the lock release operation has been described above, the lock operation can be performed according to the same principle. in this case,
In the configuration of the first embodiment, the lock signal and the lock release signal can be repeatedly generated according to the insertion of the optical key 11 by changing the operation of the output interface. Alternatively, a key having a thin film having a spectral transmission characteristic different from that of the optical key 11 for unlocking may be separately prepared, and this key may be used as a key dedicated to the lock operation. In the latter mode, the spectral transmission characteristic data on the lock operation exclusive key may be stored in advance. In other words, a plurality of different spectral transmission characteristic data are stored in the determination unit, and a plurality of keys having optical thin films corresponding to the respective spectral transmission characteristic data are provided.

In the device of the second embodiment, the control performed by the CPU and the output interface is changed,
One and the other of the angles θ1 and θ2 can be used as lock and unlock positions. Or,
It is also possible to control so that the optical key 11 is locked when the optical key 11 is inserted in the order of the angles θ1 and θ2, and unlocked when the optical key 11 is inserted in the reverse order (or vice versa).

Furthermore, the optical key device of the present invention is a key device of a type that performs a predetermined operation or processing by determining whether or not the key is appropriate, in addition to locking and unlocking. Can be widely applied.

[0035]

As described above, according to the present invention, it is possible to obtain an optical key device which does not cause wear or deterioration due to use and is hard to be copied by a third party.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an optical key device to which the present invention is applied.

FIG. 2 is a diagram showing the optical system of the optical key device viewed from the direction of arrow II in FIG. 1 together with the circuit configuration of the device.

FIG. 3 is a graph showing a spectral transmission characteristic of an optical thin film of an optical key.

FIG. 4 is a perspective view showing another embodiment of the optical key device to which the present invention is applied.

5 is a diagram showing the optical system of the optical key device viewed from the direction of arrow V in FIG. 4 together with the circuit configuration of the device.

FIG. 6 is a graph showing the spectral transmission characteristics of the optical thin film of the optical key when the rotation angle is changed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Optical key 14 Substrate part 16 Optical thin film 20 120 Key determination part 21 Insertion hole 22 White light source 23 Visible light transmission filter 24 Slit 25 Concave diffraction grating 26 CCD 27 Input interface 28 CPU 29 Memory part 30 Output interface 31 Electromagnetic lock

Claims (8)

[Claims] A key having an optical thin film having a spectral transmission characteristic that is not uniform with respect to wavelength; storage means for storing the spectral transmission characteristic of the optical thin film; and a spectral transmission characteristic of a light beam transmitted through the optical thin film of the key. An optical system comprising: a sensor for measuring; and a determination unit for comparing a spectral transmission characteristic detected by the sensor with a spectral transmission characteristic stored in a storage unit and emitting a predetermined electric signal when they match. Key device. 2. The optical key device according to claim 1, wherein the light transmitted through the optical thin film is white light. 3. The optical key device according to claim 1, wherein the sensor comprises: a spectroscopic optical system for decomposing a light beam transmitted through the optical thin film into a spectrum; and a light receiving element to which a spectrum from the spectroscopic optical system enters. Data generating means for generating spectral data of a light flux transmitted through the optical thin film based on the incident position of the light component on the light receiving element and the light intensity thereof; and the thin film transmitted light generated by the data generating means. An identification device for comparing spectral data with spectral data of a light beam that is not transmitted through the optical thin film to identify spectral transmission characteristics of the optical thin film. 4. The optical key device according to claim 3, wherein said storage means further stores spectral data of a light beam when not transmitted through the optical thin film. 5. The optical key device according to claim 1, wherein said storage means stores two or more different spectral transmission characteristics. 6. The optical key device according to claim 5, further comprising a plurality of keys corresponding to a plurality of spectral transmission characteristics stored in said storage means. 7. The optical key device according to claim 5, further comprising a key support structure capable of changing an angle of the optical thin film with respect to an optical axis of a light beam incident on the optical thin film,
An optical key device in which different spectral transmission characteristics are measured by the sensor by changing an angle of an optical thin film with respect to an incident optical axis by the key support structure. 8. The optical key device according to claim 1, wherein the predetermined electric signal generated by the determination means is an unlock signal of a lock device.