JP2922474B2 - Target and system for verifying truthfulness of object - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target for verifying the authenticity of an object, for example, a document, and a system therefor, and more particularly, to a radio frequency responsive material used in an automatic identification system for automatically identifying an item using a radio frequency signal. The present invention relates to manufacturing, radio frequency responsive targets using this material, and systems for automatic radio frequency identification of items using such targets.

[0002]

2. Description of the Related Art Automatic identification systems are widely used for inputting data to computer systems and for controlling the operation of equipment. Systems operating at radio frequencies are often used for non-contact automatic identification of identification objects or for automatic identification when gaze communication between the identification object and the sensor is not allowed. An automatic radio frequency identification (RF / AID) system is based on its operation, generally on a "target" acting as a transponder. Upon receiving the radio frequency interrogation signal, the target generates and responds to a detectable radio frequency response signal. Such targets have been in the form of tags or labels attached to identification targets. As used in the description of the present application, the term "target" refers to a radio frequency responsive means attached, printed, stuffed, or otherwise combined with an identification object. Also, in the description of the present application, the term "radio frequency" is used because the most frequently used in automatic identification is in the region of the electromagnetic spectrum. It can be understood that it also includes.

[0003] Automatic identification systems are still being used in a wide variety of ways, such as monitoring people, animals, locations, and objects, and their use is being considered. Examples of the application of such automatic identification include material management such as automatic storage and retrieval of materials, luggage management, luggage management such as transportation, rental car or theft thereof, asset management such as prevention of resale, and easy management of facilities. Includes human identification for access control or patient transport, and animal identification for automatic feeding of animals.

One of the major attributes that currently available RF / AID systems have limited their use is the nature of the cost of the target. The situation where the high cost of this target can be justified is that if the target attached to the purchased item is removed and the target is reused with other items, the item to be identified is expensive or important. And the item is likely to be abused without any effective control system. Another attribute that has limited the use of RF / AID systems is the size of the target. Typically, targets are several inches long, which limits the use of RF / AID systems when the item to be identified is small or when the target is not desired to be prominent.

[0005] Both of these attributes are mostly due to the structure commonly used in RF / AID targets and their operating frequencies. Such a target typically includes an antenna for receiving a radio frequency interrogation signal, radio frequency processing means for determining receipt of the interrogation signal, and a radio frequency response signal detectable from the target in response to the processing means. Includes radio frequency transmitting means for transmitting. Current automatic identification systems typically operate at much lower frequencies.

Due to the cost, size, and limited amount of information of prior art targets, existing RF / A
One example of an application in which ID technology has not been used is in the identification of securities documents including financial instruments such as banknotes and credit cards. Large-scale counterfeiting of banknotes using these technologies, from what is called color copying of banknotes to what is called fake printing of real banknotes, is a problem. Credit card fraud such as magnetic programming of counterfeit cards and reprogramming of genuine cards is spreading. Existing identification techniques for the identification of such items are clearly inadequate. Normal business documents (documents) are protected from being copied or used without any rights or authority, and whether they are originals,
It would be desirable to be able to prove authenticity, but there is no effective means to do so.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new RF / AID system suitable for a wide range of uses that could not be achieved by the prior art while avoiding the above-mentioned disadvantages of the prior art. It is what we aim for.

[0008]

In order to solve the above-mentioned problems, the present invention includes several embodiments useful for providing a new automatic identification device. According to one aspect of the invention, a radio frequency target includes a plurality of resonators that resonate at a plurality of radio frequencies. The resonance frequency of the resonator is used to provide identification data. In a preferred embodiment according to this first aspect of the invention, the resonator is a passive solid state resonator. In a particularly preferred embodiment, the resonator is made of a material belonging to the quartz family, such as a quartz crystal, and is formed with various desirable properties and shapes.

According to another aspect of the present invention, a method of fabricating a target having a resonator that provides identification data includes measuring a resonance frequency of the resonator. In a most preferred embodiment according to this aspect of the invention, the resonator to be used for a particular target is selected according to a pre-measured resonance frequency of the resonator. According to yet another aspect of the invention, an item is transmitted by transmitting a radio frequency interrogation signal to a target field and evaluating the response of the target field to determine whether the field contains a resonator. Be identified. In a particularly preferred embodiment according to this aspect of the invention, the frequency of the interrogation signal is varied to determine the response of the target field to different frequencies. Also, in a particularly preferred embodiment according to this aspect of the invention, the presence or identification of the target in the target field is:
The target field response is evaluated according to the frequency indicating that it is within the resonator field.

In accordance with yet another aspect of the present invention, a radio frequency target includes a plurality of resonators, which are located at spatially distinguishable locations within the target. The spatial position of the resonator is used to prepare the identification data, and the resonance frequency of the resonator can also prepare the identification data, but is not always necessary. According to this aspect of the invention, a radio frequency interrogation signal is transmitted to the target field and the radio frequency response of the target field is evaluated to determine whether the response includes the resonator and its location. The item is thereby identified. The spatial position of the resonator in the target field having a suitable resonance frequency, and possibly the resonance frequency of the resonator, is determined to evaluate the information contained in the target.

In accordance with yet another aspect of the present invention, there are provided various methods of making a target having a resonator that is spatially distinguishable. In the first method, the resonator is arranged at a predetermined information transfer position during the production of the target, and specific predetermined information is encoded. In the second method, the resonators are arranged at random positions during the production of the target, and the positions at which the resonators are placed on the target are determined. In a preferred embodiment of this second method, based on the position determination of the resonator, an automatically readable translation code is then generated, whereby the standard identification system provides the random resonator position information and the translation code information. By working with, you create the information you want to be a target attribute in a standard format. The translation code is encoded in the target itself or stored separately.

In accordance with yet another aspect of the present invention, there is provided a system for automatically obtaining information from a target including information regarding a location of the resonator in the target. In a preferred embodiment according to this aspect of the invention, a transceiver (transponder) for transmitting an interrogation signal to a target and receiving a response signal therefrom includes a resonant aperture opening adjacent to a location on the interrogated target. I have. A resonator having a resonance frequency close to the frequency of the aperture,
When present in the interrogated target, a large reflection of the interrogation signal occurs, which can easily be detected as a response signal carrying information. In a particularly preferred embodiment according to this aspect of the invention, the transceiver device includes a plurality of such remotely located detection devices, so that information acquisition from distant target locations can occur simultaneously, and the identification process can be performed quickly. .

According to yet another aspect of the invention, the resonator has a conductive structure printed, embedded, or otherwise applied to a dielectric substrate forming the target. The geometry of each structure determines the frequency that gives a detectable radio frequency response. Such frequencies and / or spatial locations of the conductive structures inform the target. This aspect of the invention is useful for identifying documents, and in a particularly preferred embodiment, the conductive structure comprises a structure in the form of alphanumeric characters that are readable by ordinary persons. This will be clearly described below, including other aspects of the present invention.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The system according to the present invention is capable of automatic item identification in a manner that is free from restrictions on gaze detection imposed in barcode systems and short-range detection imposed on magnetic coding systems. , Similar to existing RF / AID systems. The system of the present invention differs from existing RF / AID systems in that it can operate with low cost targets with small and / or large information densities. The system can also operate from a great distance and in a limited area. The information storage component according to the present invention can be formed on a target that can be easily applied to a wide range of items to be identified. Such items can be reliably identified using various low cost interrogation systems.

FIG. 1 is a diagram generally showing functional elements of an RF / AID system. The system comprises radio frequency response means 12
Includes a target 10 that acts as a carrier. Such a target 10 is attached to or incorporated into an item and detected and / or identified by a device called a scanner or reader that includes a radio frequency transmitter 20 and a radio frequency receiver 30. The transmitter 20
Radio frequency interrogation signal 26 in the desired target field
Includes a signal generator 22 coupled to an antenna 24 for generating a signal. Receiver 30 receives the radio frequency response signal via antenna 34 coupled to signal processor 32. The signal processor 32 generates an output 38 indicative of the presence of the target in the target field in response to the response signal received by the antenna 34. This output 38 is sent to a computer or other identification information processing system 39. Transmitter 20 and receiver 30 can be physically integrated into a single transceiver unit, or the functions of antennas 24 and 34 can be made doable by a single antenna. The system shown in FIG.
It is also possible to design to detect radio frequency responsive means in a field near the antenna, a field far from the antenna, or both fields.

FIG. 2 is a detailed view of the preferred radio frequency response means 12 shown in FIG. The response means 12 includes a plurality of devices that resonate at radio frequencies. FIG.
Are the frequencies fa, fb, fc. . . fn, ie, resonators 12a, 12b, 12c,. . . 12n is shown. These frequencies represent a subset of the possible resonance frequencies provided by the resonator in the target. In some aspects of the invention, the resonators may have the same resonance frequency that is not intended to provide identification information. Also,
In other aspects of the invention, the resonators can have different resonance frequencies, and certain frequencies there provide identification data to the target. FIG. 3 shows a preferred embodiment of the resonator 12n. The resonator comprises a piece of solid material having a magnitude, electromagnetic properties, and / or mechanical properties that resonate at radio frequencies. Although illustrated as rectangular prisms in the figure, it can be seen that various shapes are used for devices having stable radio frequency response characteristics.

One preferred resonator 12n is a quartz crystal. The crystal has electrical, mechanical properties that can be used as accurate, robust, reliable, and stable frequency determining elements. While resonators suitable for use in the present invention may consist solely of quartz crystals, it is also desirable to modify it, for example to improve its Q-factor, to adapt its properties to a particular use. For example, it is also desirable to dope quartz with another material, for example gallium. It may also combine a quartz crystal with a metallic auxiliary structure forming an antenna to improve the coupling of radio frequency energy incident on the crystal, or alternatively, as is done for example in surface acoustic wave devices.
It is desirable to control the mode of operation of the quartz crystal. Quartz crystal is the preferred resonator, but useful solid resonators can of course be made from other crystalline materials or even amorphous solids. For example, other preferred resonators include thin dipoles
s), materials that operate in electron paramagnetic resonance, and ferrite materials that operate in ferroelectric mode. In addition, other characteristics besides the resonance of such resonators may be detected to obtain identification information, as described below with respect to some embodiments of the present invention. For example, a short circuit effect of a thin dipole or similar resonant conducting structure can be detected by a suitable transceiver.

Such a resonator 12n can be configured to resonate at several frequencies and to obtain identification information on the target using those several frequencies. Anyway, the resonator has at least one resonance frequency,
That is, some embodiments of the present invention are configured to resonate at the information carrier frequency in the system. Although various ranges of frequencies may be used in the system according to the invention, higher frequencies may be preferred for various reasons, such as availability, required resonator size, identification range, and control over the interrogation signal. Thus, for example, frequencies above about 1 GHz are preferred, especially frequencies above about 10 GHz. The frequency can be used up to 500 GHz which is close to the frequency of visible light.

FIG. 4 is a diagram showing an outline of how identification information is prepared according to an embodiment of the present invention. FIG.
Is a graph showing the relationship between attribute numerical values and frequency with respect to frequency. Frequency domain can be multiple bands or "windows"
, Each of which represents a binary number or bit value. Thus, the number of n-bits requires n distinct frequency bands. One or more "start" bits are required for the target. Therefore, for example, 60.0-6
The 0.1 GHz identification band is divided into ten 10 MHz wide windows, including several "stop" bands between the desired adjacent windows. In this system, these windows are defined as representing one start bit and one 9-bit data word. With respect to the example shown in FIG. 2, any of the resonators 12 there
Is also required to belong to one of the ten frequency windows defined in this example system, and 10
One resonator is required to provide one start bit and all nine available bits to the target.

From FIG. 3, one bit of information is required to provide one bit of information by resonance, and one solid resonator as shown is required, and although sufficient, the individual resonators forming each of the identification resonance means of FIG. It is understood that it is desirable to use a large number of crystal resonators. Increasing the number of individual resonators is an inexpensive and reliable way to increase the responsiveness of the target to the interrogation signal strength applied to the target. Thus, by providing a large number of crystals, each having a frequency in the window, the presence of corresponding data bits at the target can be determined using low power interrogation transmission and / or low gain reception which is highly desirable in a given application. Detection from a long distance.

An important point of the present invention is that an inexpensive, accurate and stable target resonance device can be provided. As mentioned above, the preferred resonant device includes a quartz crystal forming a solid passive resonator. At present, quartz crystals are produced in large quantities for frequency determination, but probably those manufactured by current manufacturing techniques are:
Too expensive for those trying to use it economically with the RF / AID system according to the invention. Such expensive crystals are carefully cut to precise dimensions to make products that meet the very tight frequency tolerance requirements.

In order to avoid the limitations of existing production techniques and to produce in large quantities and inexpensively the crystals used in the system according to the invention, there is provided a novel production method comprising a total of two steps. The first step is to mass-produce solid-state resonators, such as quartz crystals, inexpensively, so that each resonator has resonance characteristics that fall reasonably well into the identification band of the system. Second
In the stage, the characteristics of the resonators as manufactured are measured, and the resonance characteristics of the individual resonators are determined.

A preferred method of providing a solid-state resonator is to form a resonator made of a solid material to a substantially desired size, and measure the resonance characteristics of the resonator to select the resonator. Applicants believe that the following method satisfies the needs of the present invention. When the quartz is heated sufficiently, the quartz becomes somewhat soft before it liquefies. The quartz thus heat-softened can be easily cut and / or shaped into a size and shape suitable for use as a radio frequency resonator. Accordingly, the quartz mass is heated and softened, cut into individual crystals through a forming die in a process similar to extrusion, and then cooled, for example, by a quenching process. The quenching process is
This is performed by immersing the crystal in water, oil, petroleum-based liquid, or other hydrogen, oxygen, or carbon-based liquid. The crystals so produced are collected for further processing. Of course, other methods can provide a number of crystal resonators or other resonators having substantially appropriate characteristics.

[0024] Desirably, the process of manufacturing resonators with nearly correct resonance characteristics will produce a characteristic distribution that exactly corresponds to the resonance characteristics required for the resonator in each window. A general manufacturing process is to make a resonator having another distribution, for example, the resonator has a normal distribution of frequencies. Such a distribution is RF
Desirably, it substantially matches the range of the particular identification band used in the / AID system. For example, FIG.
It shows a nearly normal distribution centered on 0.05 GHz. This distribution is between 60.0 and 60.1 as described with respect to FIG.
This is a distribution that occurs in the process of fabricating resonators with approximately the same number in each GHz window.

When production of a resonator having different characteristics starts,
The resulting resonator is incorporated into an information transport target. 6 and 7 show two target manufacturing methods that can be identified by the frequency for RF / AID. FIG. 6 shows a preferred method according to the invention for producing such a target. In step 40, a set of resonators is manufactured by a process designed to manufacture resonators having different resonance frequencies near the desired value. The frequency of each resonator is measured at step 42, and at step 44 the resonators are sorted by frequency according to the measurements made at step 42. For example, a quartz crystal resonator may be assembled as described above, carried to a measurement system similar to the system shown in FIG. 1, and each crystal may be identified, or preferably identified, with another crystal having the same or similar frequency. Are separated and sorted. Referring to FIGS. 4 and 5, upon completion of the sorting step 44, ten containers are provided, each containing crystals from only one frequency window representing only one information bit. A set of crystals having frequencies representing the bits of the identification digital word is selected at step 46, and at step 48 a target is created using the selected crystals. According to the method shown in FIG. 6, a target including predetermined identification data is created.

In contrast, the method shown in FIG. 7 is a method of creating a target that includes random or uncontrolled identification data instead of predetermined identification data. After assembling the resonators having different frequencies in step 50,
In step 52, one set of resonators is randomly selected,
Then, in step 54, the target is incorporated. Then
In step 56, measurement is performed to determine the frequency of the resonator incorporated in the target. The measured data is stored at step 58 so that it will be validated when the target receives the interrogation signal during actual use.

FIG. 8 illustrates a preferred method of generating and processing a radio frequency signal according to the present invention. According to this method, the target field receives interrogations for the resonator that can occur by changing the transmission frequency within a range that includes the applicable information carrying band of the system. FIG.
In the pair of graphs shown in FIG. 1, the upper graph is a graph showing the change of the interrogation signal frequency with respect to time, and the lower graph is a graph showing the possible radio frequency response coming from the target field at the same time interval. As shown in the upper graph of FIG. 8, the frequency of the interrogation signal changes from the lower limit to the upper limit, and the lower limit and the upper limit correspond to FIG.
fs and fn. When the upper limit frequency fn is reached at the time T, this change is repeated immediately or after a certain time. Preferably, the frequency sweep is substantially linear and continuous, as shown, but other predetermined changes may be used. The lower graph of FIG. 8 shows the response signal generated by the target field and detected by the signal processor 32. This signal indicates the difference from the background signal and is shown by spikes in the figure, but may take other shapes. The graph below shows the key features of the swept frequency measurement. That is, the identification data indicates that it can be easily detected by measuring the time at which a spike or other resonance effect occurs during the response.

Referring to FIG. 4, if the frequency band is partitioned into ten windows by a start bit and a low frequency window showing nine data bits from the lower bits of f1 to the upper bits of f9. The data word indicated by the response of 8 is 10,0001000
Becomes Such a serial data structure can be easily and inexpensively evaluated. Using the start bit frequency as described above, or using other data structures that can be evaluated by relative frequency determination, rather than absolute frequency determination, can reduce the cost of the detection equipment. As a result, it is possible to avoid the difficulty and cost of performing high-resolution and high-accuracy frequency measurement at high frequencies.

The lower graph of FIG. 8 shows a response signal having an amplitude greater than the signal received at another frequency and with spike-shaped identification information. Also notice that the response signal forms a trough or a notch (V-step) where the resonator absorbs energy at a particular frequency, eg, the resonance frequency. What is needed is whether the resonator is providing a detectable difference in the response signal at an identifiable frequency, ie, whether the response signal is greater or less than another frequency.

It should be noted that by transmitting a high power interrogation signal with a small duty cycle, a low average power level can be maintained while using a large measurement signal. For example, 1 from low frequency to high frequency
The interrogation signal, which is swept at ms intervals and then pauses for 9 ms, resulting in a 10% duty cycle, increases the available response signal level by a factor of 10 from a given average transmit power level.

The system described above is applicable to a wide range of targets and identifications. For example, the resonator is very small, on the order of the wavelength of the interrogation signal. 10
Half-wavelength sized resonators at frequencies on the order of 100 GHz are quite small, and many are used to generate high-density identification data much larger than the nine bits illustrated with respect to the description of the earlier figures. Can be provided. A particularly desirable mode of application of the resonator identification set is to encode "ink" in a matrix of sticky radio frequency transparent material
It is a usage to form This ink can be widely applied to various types of materials, and can be used to identify those materials. A notable use of this ink is in document identification. Inks containing radio frequency resonators can be applied to tag or identify a wide variety of documents. The scope of application of this ink is to replace barcodes, indicia printed on checks, banknotes, etc., electrostatographically copied documents, laser printed documents, or any other printed by thermal transfer technology or otherwise. It covers a wide range from inclusion to toner that allows monitoring and / or identification of documents. The crystal of the identification crystal or a set thereof can also be encapsulated in a microcapsule or included in the body of the material to be identified.

Another notable application of this ink is to modify the response characteristics of the target. This application has been made in the prior art, for example, in the deactivation of retail theft control tags and labels. The system of the present invention can also modify the response characteristics of the target, for example, to deactivate the target or otherwise change the information it contains. FIG. 9 shows a system for correcting the response characteristics of the target. The resonator 60 is coupled via a coupling means 62 to a resonance correcting means 64 having resonance characteristics. This coupling means 62 changes due to external influences, and changes the coupling between the resonator and the resonance correcting means 64. When an appropriate stimulus is given to the coupling means 62, FIG.
The resonance characteristics of the whole system shown in Fig. 4 change and change the information there. By including one or more such systems in the target, the target has the ability to change the target information.

One possible example of the system shown in FIG.
It is a quartz crystal encapsulated in microcapsules of a heat-deformable medium that functions as both the coupling means 62 and the resonance modifying means 64. At low radio frequency power levels, the mechanical coupling between the capsule and the resonator affects the natural resonance characteristics of the resonator. Applying a high level of radio frequency power sufficient to generate heat due to the movement of the resonator deforms the encapsulating medium, thereby changing the coupling and effect of the encapsulating medium on resonance characteristics. This change can be interpreted as a change in information. Another example of a tunable resonator is a pair of crystal resonators that are mechanically coupled by a thermally deformable medium. When the resonators are integrated, they both exhibit a first resonance frequency.
When a high level of power is applied at the resonant frequency, the resulting heat deforms the coupling medium, and each component resonator resonates at its own resonant frequency, changing the information contained in the target.

FIG. 10 illustrates various aspects of the present invention in which the spatial position of the resonator at the target gives information to the target and information is obtained from the target by detecting that position. It is shown that it is possible. These aspects are particularly useful for identifying items of a target that can be easily accessed by a transceiver reader that facilitates discrimination of the spatial position of the resonator within the target. Examples of such uses are:
With a two-dimensional area (plane) that can be encoded by the resonator and with well-known document handling techniques,
One example is the identification of documents that can be separated and handled individually. Other examples include credit cards and similar card sized documents traditionally formed of plastic and encoded by magnetic means, which can be handled by well-known card handling devices. The label or tag applied to the surface for the identification of the cards can again be spatially encoded by the resonator. All such specific embodiments are collectively referred to herein as "documents." As already mentioned, in aspects of the invention, the resonance frequency of the resonator is used for important information about the target.

FIG. 10 shows a document 70, which is encoded with positional type information from a set 72 of resonators 72a-72n attached thereto. Although these resonators 72 are shown as line segments, the resonators may be, for example, thin metal pieces, i.e., thin dipoles made of elongated metal or metal-treated material having chaff properties.
(thin dipole). Such a dipole resonates at an interrogation frequency such that the length of the dipole is one half its wavelength. Metallized glass fibers can be used as thin dipoles, the diameter of which is about 0.001 inch. Various lengths of glass fiber can be used depending on the desired resonant frequency and the nature of the reader, but in this example a length of 1/4 inch is used. FIG. 10 shows rows 1, 2,
3,. . . m and columns 1, 2, 3,. . . A rectangular array consisting of n is indicated by a dotted line. This mxn array is typically formed by an encoding / decoding (or "coding") scheme and is defined by a scanner or reading device that reads the document 70, but is not necessarily an attribute of the document 70. While it is possible to accurately determine the spatial location of each resonator in a document, in a preferred embodiment, by detecting the presence of a resonator in a spatial "window",
Avoid this annoying task. That is, a preferred reading device determines the presence or absence of a resonator anywhere within a predetermined area of a document containing an array element (m, n) as one information bit under a particular encoding scheme. I do. The read information bits are organized as a single data word or multiple words (eg, each row or column is considered a byte). As described in detail below for the reading device,
The origin of the array can be determined with respect to the location of the resonator of the document containing the "start" data, or the document itself, for example with respect to the edge of the document.

FIGS. 11 and 12-14 show two generally available methods of providing a document containing information encoded by the spatial position of the resonator. These FIGS. 11 and 1
3 and FIG. 14 are each separated by a horizontal dashed line,
The upper part of the dashed line consists of the "writing" or preparation of the coded document, the lower part consists of the "reading" of the document and, if readable, the decoding of the coded information there. ing. In the method shown in FIG. 11, a document is encoded by arranging a resonator at a predetermined position, and the method shown in FIGS.
In the method shown in FIG. 14, the document is encoded by arranging the resonators at random positions.

In the flow chart of FIG. 11, a resonator is first fabricated at step 80 to provide a resonator that is properly included in the document to be identified. In step 81, the coding (encoding) system used for encoding the document is determined. The coding system combines predetermined information with a predetermined spatial location in the document, and can be selected from a set of available coding systems. In step 82, the information to be encoded in the document is determined. In step 83, the position in the document at which the specific information to be encoded (determined in step 82) is to be encoded is determined according to the particular encoding system used (determined in step 81). In step 84, the resonator is arranged at the position of the document determined in step 83. This step 84 can be performed by placing the resonator during the stage of making the substrate for the document. For example, a paper pulp web (eg, for banknotes) may be placed from a source of resonators, or a soft plastic (eg, for a card) may be in a fluid state as it was formed. Place it from a resonator source before the printing or magnetic encoding material is applied. Step 84 may also be performed by applying a resonator to the document after completion of the substrate and before or after printing, magnetic material, or other non-resonant information carrier material is applied to the document. You can do it. After completion of step 84, "writing" on the document is performed by providing a resonator at a predetermined spatial position carrying information.

The reading steps 86 and 88 in FIG.
Is performed using a reading device as described below with reference to FIG. In step 86, the position of the resonator in the document is determined. This step includes a discriminating step of determining the characteristics of each resonator from, for example, the frequency of the resonators and determining whether it is genuine, or whether further information can be identified. In step 88, if there is any information in the document, using the encoding system to be applied to the document (if authentic and properly encoded),
The document is decoded under the encoding system based on the position of the resonator determined in step 88.

In performing step 84 of the method shown in FIG. 11, it is difficult and costly to control the position of the resonator.
14 to FIG. 14 are preferable. In step 90, a resonator is fabricated to provide a resonator supply. In step 92, the resonators are randomly or uncontrolledly placed on the document. This step 92 is performed during or after the formation of the document substrate and before or after the application of other information carriers, such as printing, magnetic material, and the like. In step 94, the positions of the resonators randomly arranged in the document are determined by passing through a reading device shown in FIG. 15, for example. In step 95, the information that is desired to be encoded in the document (ie, the information indicated by the location of the resonator) is determined. In step 96, the determined information is used as the attribute of the spatial position of the resonator determined in step 94.

Step 96 is performed in several ways. One is shown in FIG. 13 and the other is shown in FIG.
It is shown in FIG. Each of these figures includes a reading step appropriate for the particular information attribution method shown. In FIG. 13, an attribute setting step 96b of information is a step of storing data relating a resonator position in a document to information serving as the attribute. This step is implemented, for example, in a digital memory including a reading device, or receiving information from the reading device. Such data is created as a look-up table. In the reading process of the document incorporating the information, first, in step 98, the position of the resonator in the document to be read is determined. Next, in step 98, the stored data is examined to search for data corresponding to the determined position. When the position data is found, the embedded information is extracted from the stored data, and the document is decrypted. In a simple example, if the information of interest consists only of authentic information, the stored data consists only of the position of the resonator of each authentic document created using the writing step. During the reading process, if a data entry is found at such a location, the document is determined to be authentic, ie, genuine, otherwise it is determined to be counterfeit, ie, not genuine. The method shown in FIG. 13 requires that the reading device can access the stored data generated during the writing process.

The method shown in FIG. 14 does not need to save the position and information relating to each authentic document (performed in step 96b), and is suitable for a case where information obtained from the document in a specific format is desired to be output by a reading device. It is. Therefore,
At step 96c, a translation code is generated. The translation code is an algorithm or data used in a predetermined algorithm. When this translation code is applied to position information of a document, information desired to be attribute of the document is given in a predetermined format. Thus, the translation code is unique to each different document resonator position set and to the formatted information that is attributed to each different document. In step 102,
Save the translation code and complete the writing process. In step 104, when the reading process starts, the resonator position of the document to be read is determined. In step 106, the stored translation code is read. In step 108, the translation code is applied to the determined resonator position to determine document information (if any) and decode the information.

As an example showing the difference between the methods shown in FIGS. 13 and 14, let's look at the method of checking a credit card. The system preferably includes a number of commercial equipment readers located at different locations, each of which preferably has the ability to determine whether the submitted card is a genuine card. The verification method provides the merchant with information printed on the card, such as a card number written in Arabic numerals, expiration date, cardholder name written in English, etc., in a certain format that can be compared to the merchant. In the method shown in FIG. 13, when reading the resonator location of the card, the merchant references the location information from the submitted card and obtains a database containing stored data on all valid credit cards to obtain formatted attribute information. Need to access It is not practical for such a huge amount of information to be stored by a merchant's reader, so the resonator position information and decoding information is stored between the merchant's reader and the large central database. Must be replaced at FIG.
In the method shown in FIG. 4, the translation code storage step 102 is performed by storing the code on the card itself, so that it is difficult to place the resonator in a predetermined position. This can be avoided by performing, for example, printing, bar coding, magnetic coding, and the like. To decode the resonator information and give it to the merchant in the desired format, each merchant's reader only needs to apply the translation code to the determined resonator position data (possibly, (In combination with the means for automatically reading the data). This can be done autonomously by the merchant's reader without accessing the central database.

FIG. 10 shows a translation code incorporated in the document 74. The translation code is located in an area 76 of the document, which area may be a complete part of the document itself, or may comprise a label applied to the document 74 or the like. Translation codes are alphanumeric characters 76a, barcode symbols 76b, magnetic materials 76c, radio frequency responders 7.
6d or other types. These types can be used alone or in combination.

FIG. 15 is a block diagram schematically showing a document reading apparatus which can be used to read the document shown in FIG. 10 by the method shown in FIGS. 11 and 12 to 14. The components of the reading device are contained in a housing 111, which has an entrance 112 for receiving the document to be read.
And transport means 116 for transporting documents along a path P from the entrance 112 to the exit 114. Radio frequency source 112 is coupled to a resonant aperture 120 provided adjacent to path P. It is preferable that at least one, and preferably a plurality of such resonance diaphragms 120 are included.
When a plurality of resonance diaphragms 120 are used, their resonance frequencies may be the same or different. A radio frequency detector 124, such as an envelope detector, is arranged to detect radio frequency energy generated by an RF (radio frequency) source 122 preselected by the resonant aperture 120. As the dipole taggant moves along path P and covers the aperture of the resonant aperture 120, the aperture aperture has a low impedance close to a short circuit. In such a situation, a large reflection of the irradiating radio frequency occurs and the radio frequency energy is kept constant but greatly reduces the radio frequency voltage at the aperture. Such a condition could be to place a detector on the radio frequency source side of path P (shown in FIG. 15) to detect the energy reflected from the resonant aperture or to reverse the path P as viewed from RF source 122. It is detected by placing a detector on the side and detecting the energy propagating through the resonant aperture 120. control/
Processor 126 controls the operation of reader 110 and processes information derived from the document. This functional block is executed by various systems based on a microprocessor, and the configuration can be said to be easy for those skilled in the art. The preferred system is
It includes a microprocessor, a memory containing an operation program of the system according to the present invention, and an interface device for connecting the microprocessor to other functional blocks shown in FIG.

The longitudinal position of the resonator in the document being scanned correlates the maximum low impedance effect detected by the radio frequency (RF) detector 124 with the position of the document along the path P. Can be determined by For example, regarding the embodiment shown in FIG.
An edge detector 118 is provided that outputs a signal to the control / processor 126 when an edge of the document passes the edge detector 118. This edge detector 118
It comprises a light source and a photodetector arranged so that the light path from the light source to the photodetector is blocked by a document carried along the path P. The control / processor 126 can determine the position of the document edge with respect to the edge detector at any time by integrating the document speed along the path P some time from the edge detection. The document speed is responsive to either a speed signal transmitted from the transport means 116 to the control / processor 126, or a control signal transmitted to the transport means 116 if the document speed is controlled by the control / processor 126. Determined by control / processor. The position of the document edge with respect to the resonant aperture 120 is calculated according to the distance between the resonant aperture and the edge detector.

As indicated above, the edge detector 118 may be omitted and other means may be employed to construct a reference space frame for determining the location of a taggant in a document. These other means include the use of a radio frequency detector 124 to detect a "start" taggant in the document, or another means to detect printing or other features that provide one or more spatial reference points on the document. The use of a type of detector (such as a photodetector) is included.

In the preferred embodiment of the reader 110, each resonant aperture is fixed in its own position, and when a document is entered at the entrance 112 and transported with its edge 74 leading, each aperture will be one column of the document. You can read.
A plurality of resonant apertures are suitably provided (in combination with the radio frequency source 122 and the radio frequency detector 124),
Each is arranged laterally along the path P so that one column of the document can be read. Such an arrangement is shown in FIG. 16 and will be described later. However, it will be appreciated that the spatial location of the taggant relative to the two-dimensional area of the document can be detected using other methods and other types of equipment. For example, as the document is advanced along path P, single resonance aperture 120 may be reciprocated laterally to sweep or scan each row of the document. Also, the document is fixed in the reading device 10, and a single resonance stop 1
20 can also be moved in both the vertical and horizontal directions, thereby eliminating the need for the document conveying means 114. While such a reader minimizes the need for a radio frequency device, its mechanical complexity can make the device less desirable compared to the reader shown in FIG.
On the other hand, eliminating the need for relative movement of the document and the resonant stop 120, one resonant stop (radio frequency generator and radio frequency generator) for each grid element (i, j) where the taggant can be placed by the document coding system. By providing (in combination with detectors) mechanical complexity is minimized. However, apart from a system that uses only a small number of possible taggant positions, the cost and complexity of providing many radio frequency systems would make such an approach undesirable.

Once the spatial reference of the document in the reader 110 has been determined, the longitudinal position of the document relative to the taggant 72 can be determined by the control / processor 126 by the radio frequency detector 124 to determine the minimum impedance at the diaphragm 120. It can be determined based on the time to detect the value and the speed of movement of the document along the path P. Generally, the surface of the document is distributed in grid or array coordinates (i, j) by the software of the control / processor 126. Each grid element (i, j) is assigned a binary value (1 or 0) depending on whether a minimum value of impedance is detected at the document position corresponding to this grid element. The assignment of data bits to lattice elements can be done in various ways.
For example, several times the minimum value of the impedance is measured and compared to a time "window" applicable to the spatial boundaries of the grid elements. As an alternative, a data holding device such as a latch is provided for each lattice element, and the lattice element is operated for a predetermined time interval corresponding to a time interval on the resonance aperture, and the data storage element is operated. A comparator produces a logical output according to whether the impedance of the resonant aperture exceeds a threshold. The logical value is held in the data storage element.

The reader 110 includes an output 128 for local output of information obtained by reading a document. The output 128 is, for example, a display for visually displaying alphanumeric characters. In addition, the reading device 110 is an I / O
Port 130 includes, for example, a modem for transmitting information obtained by reading a document to a remote location over communication channel 132. In general, outputting information from a document in a predetermined and convenient form is more convenient than outputting as a binary sequence or binary word of raw data indicating whether a taggant is present at each grid element. It is preferable to output. Therefore, the control / processor 126 is configured as shown in FIGS.
And 14 respectively comprise data processing algorithm means for performing the decoding steps 88, 100 or 108 respectively. If the method shown in FIG. 14 is to be adopted, the reading device 110 automatically includes a translation code reading device for automatically reading the translation code of the document and supplying the translation code to perform the step 108. preferable. The light source 144 such as a photodiode is
Together with the photodetectors, they form part of an edge detector 118 (typically located above path P, but not shown here).

FIG. 16 is a plan view of an interface surface of a document used in the document reading apparatus shown in FIG. Although the reading device 110 of FIG. 15 is shown as a block diagram, this plan view of FIG. 16 is viewed downward from the path P toward the resonance diaphragm 120, the edge detector 118, and the transport means 116 of FIG. It corresponds to the thing of the time. A plurality of feed rollers 142 driven by suitable means (not shown) such as a motor, including transport means 116, are arranged to transport the document along or near surface 140, with or near surface 140. You. Each such feed roller 142 is positioned adjacent a cooperating drive or idle roller (above path P, and therefore not shown) to form a nip (roll gap) through which documents pass through roller 142. Conveyed by the rotation of. Other known document transport techniques, such as a belt system, can also be employed. Each of the plurality of radio frequency holes arranged on the surface 140 has a resonance aperture and is illuminated from below by a radio frequency source (not shown). At least one such hole and aperture is provided for each column of the grid array (FIG. 10) defined by the coding system used. As shown in FIG. 16, two apertures are preferably provided for each column, ie, vertically deflected aperture 146 and aperture 148 and horizontally deflected aperture 150 and aperture 152. It is preferred to use both such horizontally and vertically deflected components whenever the orientation of the taggant in the document changes. For example, as shown in FIG. 10, the dipoles 72 are arranged at various angles ranging from 0 ° to 360 °. This is the result of the random arrangement of the dipoles or the purposeful arrangement of the dipoles at a predetermined angle. The dipole detection is generally a cosine function of the angle of the dipole with respect to the deflection axis of the resonant aperture. Accordingly, the dipole 72a of FIG. 10 has a maximum short circuit effect near the stop 148 and a minimum impedance effect near the stop 152. The opposite is true for dipole 72c. Thus, the orientation of the dipole taggant in the document can be used to encode the document information in addition to the location of the grid, and use both horizontal and vertical deflection antenna elements to determine the angular orientation of the dipole. Thus, the information can be decoded. If the dipole orientation is not used to encode information, both horizontal and vertical deflection antenna elements are used to ensure that at least one of the apertures has a detectable impedance change, so that the dipole has its orientation. Regardless, it can be detected with reliability.

A variation of the present invention, particularly desirable for use with credit cards and similar documents, is shown in FIGS. FIG. 17 shows the "back" side of a card 172, such as a credit card, and FIG. 18 shows the side of the card with emphasis on thickness. The card has a conventional structure as a whole, for example, a pair of inner plastic layers 160, 162 consisting of an opaque PVC sheet having a thickness of 0.012 inches and a clear P05 layer having a thickness of 0.0005 inches.
It includes a pair of outer plastic layers consisting of a VC sheet. Printing is provided between the outer and inner layers, with the outer layer visually protecting the print. Card 1
Reference numeral 72 denotes a conventional magnetic data storage means, for example, a magnetic strip 168.

The difference of this card 172 from the conventional one is that the card 172 includes a plurality of resonators, and information is encoded by the positions of the resonators in the card. A preferred resonator is a thin dipole 170 of the type described above, such as a metal or metalized fiber. Also,
The resonator may comprise a metal or conductive structure disposed on a non-conductive substrate, as described below with reference to FIG. The dipole 170 may be located anywhere on the card, but the preferred location is the inner layer 16.
It is preferably between 0 and 162, and is placed in a predetermined position for encoding specific information or is randomly placed before laminating the inner layer in the card manufacturing process. The dipoles may be distributed uniformly over the entire area of the card or, as shown, limitedly distributed over a predetermined area. A particularly preferred location of the data encoded resonator 170 is in the area adjacent to the magnetic strip 168, as shown in FIGS.
This position is preferred for a number of reasons, including the difficulty of duplicating the card, the first of which is that the card is magnetically and "swipe"
pe) "is also capable of reading both types of data by using a radio frequency by a credit card reader of the" type ". FIG. 19 schematically shows a card reader which can read both types of encoded data.

This reading device includes means for reading magnetic data contained in the magnetic strip of the card, and means for reading radio frequency data from the card. The device is configured as a swipe-type reading device, which in use has one side of the card, the opposite side of which is placed in the slot, i.e. the lead track, and the card is manually placed along the slot on the wall of the slot. Pass in front of the fixed reader. The slot or lead track 182 shown in FIG. 19 includes a pair of sidewalls 184, 186, and a magnetic detector 190, such as a magnetic strip read head, is adjacent to the magnetic strip when the card is swiped through the slot. To one of the slot walls. The output of the magnetic detector 190 is provided to a control / processor 188 which controls /
A processor processes the received data and outputs data to local output device 20.
2. Generate output to, for example, a visual display, and communicate with other devices via I / O port 202 as needed. In addition to the normal functions of this magnetic card reader, the device shown in FIG. 19 also includes a radio frequency reader. The preferred device shown in FIG. 19 includes a radio frequency (RF) source 192 that provides radio frequencies to the radiation holes via a circulator 194. This radiation hole 1
96 is located on the wall 186 of the slot 182. Radio frequency energy propagates from radio frequency source 192 through circulator 194, antenna aperture 196, and further through the space of the slot to wall 184 opposite the slot. The wall 184 of the slot reflects energy back into the antenna aperture 196 where an appropriate amount of energy is collected and propagated through the circulator 194 to the radio frequency detector 198. This radio frequency detector 198
Can be constituted by a diode functioning as an envelope detector. This reading device functions as a transmission line having a standing wave.

The radio frequency reading device operates in the slot 18
When there is nothing at 2, the power at the detector 198 is mechanically positioned to peak. This positioning can be accomplished by setting the gap between the detector 198 and the opposing wall 184 to be 1/4 of the wavelength at an operating frequency of about 25 GHz. As the card containing the thin dipole passes through slot 182, the dipole substantially short-circuits the radiating hole and shifts the phase of the standing wave in the transmission line by approximately 90
° shift. The resulting energy drop is detected by radio frequency detector 198 and the detection signal is controlled /
Sent to processor 188. The spatial location along the card where such energy reduction occurs can be determined very accurately because the detection system measures the absence of standing waves during radio frequency transmission. This allows
A high-density pack with a radio frequency element and a large data capacity becomes possible.

The combination of magnetic data that can be read by a single reader and radio frequency data in a single card offers several advantages.
First, the magnetic strip can be used to store translation code data for use in the coding systems described above. Second, the magnetic strip contains clocking data that can be shared with the card and used to form a suitable reference spatial frame for radio frequency measurements. FIG.
The reading device shown in (1) includes a document conveying means capable of controlling or measuring the speed of the document as the document passes through the radio frequency detector, but corollates a spatial position having the detected radio frequency data. Therefore, the swipe-type reading device lacks a document conveying means.
To illustrate the change in speed of moving the card through the slot in the device shown in FIG. 19, the detected radio frequency signal is a time correlated with the detected magnetic signal, including the magnetic clocking signal. These can be used to construct a spatial framework for the encoded radio frequency information.

FIG. 20 is a graph showing various signals generated by the reading device shown in FIG. The horizontal axis is located along the card to be read and the vertical axis shows the signal amplitude. Waveform 214 shows the clocking signal stored on the magnetic strip. Waveform 212 is a radio frequency signal provided by detector 198 and includes a reduction in energy caused by the presence of three dipoles at different spatial locations along the card. Such signals are due to the arrangement of the dipoles on the left side of the card, as shown separately in FIG. Alternatively, if the dipoles are randomly distributed as shown on the right side of the card in FIG. 17, a plurality of randomly oriented dipoles in the antenna field may be smoother, as shown in waveform 210 in FIG. Draw the waveform of the radio frequency amplitude versus (vs) position. This radio frequency amplitude vs.
The position waveform characteristics can be used to uniquely identify the card. Further, the information may be an attribute of the data obtained by sampling the detected radio frequency amplitude at a given spatial location, and may be an attribute of the detected amplitude.

Although the reader of FIG. 16 has one radio frequency detector and one magnetic detector, it can include a plurality of radio frequency systems including systems having different deflections, operating frequencies, and the like. It turns out that it is. If the card is passed through a radio frequency head, magnetic data can be obtained at the same time, and a plurality of magnetic detectors can be provided so that the position can be determined. Finally, it can be seen that the magnetic head and the radio frequency head can be positioned along any slot wall at the appropriate location to perform the required measurements.

FIG. 21 shows a type of target that can be used to advantage in many RF / AID systems. Target is substrate 2
20, on which a plurality of resonator structures are arranged. The target substrate is preferably formed of a thin plastic sheet, for example, a 0.0005 inch thick polyester film or PVC film. The structure responsive to radio frequency disposed on the target substrate is preferably a metal structure, for example, a structure made of aluminum. FIG. 21 shows a substrate 220 on which some type of radio frequency responsive metal structure is disposed. Thin dipoles can be placed on this substrate, and the dipoles 224 and 226 shown resonate at different frequencies due to their different lengths. More complex structures can be advantageously used. These structures include structures 222 in the form of letters, numbers, or other characters or symbols. Such a structure has, in addition to the transmission of information that can also be determined by visual inspection, a resonating property with respect to the radio frequency associated with the size and shape of the character. Although a thin film with aluminized letters as shown in FIG. 21 is used in US currency as a counterfeit prevention measure, this structure itself does not form part of the present invention. However, in accordance with the present invention, such a structure can be read at radio frequency and by correlating the actual radio frequency response with the expected frequency response for a given character set, currency and object Can be proved authentic. If the character set is determined in advance, the reading device can have information on the expected radio frequency characteristics of the character set in advance. If the information contained in the target is not uniform and is not predetermined, the resonant structure can be read optically, at radio frequency, and the result can be used to prove the authenticity of the target. Correlated. Other structures sized and shaped for a particular radio frequency resonant response
It is also possible to arrange in. For example, metallized 2
28 provides both resonance frequency and phase information.

A given target may include one or several different types of radio frequency responsive structures suitable for its use. Depending on the type of resonator included in the target and the information contained in the resonator,
These resonators are read by a wide variety of readers, including the far field frequency responsive reader shown in FIG. 15 or FIG. 19, or the near field frequency responsive reader. Thus, the target of FIG. 21 functions like the target 12 of FIG. 2, the document of FIG. 10, or is laminated between the layers of the card of FIG. 17 to provide a radio frequency response data component.

The target shown in FIG. 21 can be manufactured by various techniques. These manufacturing techniques involve coating a plastic film substrate with a thin layer of metal (eg, 300 angstroms thick) by vapor deposition or equivalent means, and printing or resisting the area where the metal layer should remain on the finished target. The method includes a step of protecting with a developable resist and removing other metal layer regions by chemical etching.

FIG. 22 is a block diagram illustrating the general functions of a preferred radio frequency reading system according to the present invention. A radio frequency (RF) source 240 is coupled to the transmission line 242 and generates a radio frequency signal carried along the transmission line. The transmission line 242 includes at least one radiation hole 246 through which a radio frequency signal is radiated into space. A radio frequency (RF) detector 248 is arranged to receive a radio frequency signal affected by the presence of radio frequency responsive objects in the near field region of the radiation hole 246. The radio frequency reader is in the near field region of the radiation hole 246,
Output signal 24 having a signal component responsive to radio frequency conditions
9 is provided by a radio frequency detector 248 provided at various physical positions satisfying the function of outputting the signal 9. By detecting signals responsive to radio frequency conditions in the near field region, the location and characteristics of objects that respond to radio frequency, such as resonators, can be determined. The reading device shown in FIGS.
1 includes an embodiment of the general system shown in FIG.

FIG. 23 has the general functions shown in FIG.
FIG. 20 illustrates a suitable microwave reading system suitable for use with the reading device of FIGS. 15, 16, and 19; In FIG. 23, a radio frequency source, such as a Gunn diode, provides a signal to waveguide 250. The signal is sent from waveguide 250 to waveguide 252 by ferrite circulator 262. The waveguide 252 has an opening 254
, Where the signal is emitted into the near field region. The opening illustrated in FIG. 23 is the opening 254 of the stop 256. Although the use of the stop 256 is desirable for various reasons, it need not be provided, and the waveguide 252 may simply terminate the radiation hole. The signal returning to the device from the aperture via waveguide 252 is sent by circulator 262 via waveguide 258 to a detector diode where it is detected. Thus, circulator 262 acts as a duplexer coupling both the source and the detector to the aperture.

Rather than providing a conventional antenna to direct radio frequency radiation into a beam in the far field from the aperture, in accordance with the present invention, the apparatus does not use such an antenna, but instead uses a target in the near field of the aperture. Can be read. Therefore, the target guide is provided to position and / or guide the target so that the target can move near the opening,
Radio frequency response characteristics of the target can be detected in a small area of the target, and the detected radio frequency response characteristics can be correlated with the position of the target exhibiting those characteristics, and identification data can be read from the target. . The signal path through waveguide 250, circulator 262, and waveguide 252 corresponds to and is an embodiment of the transmission line of FIG. In FIG.
The signal path from 4 to the detector diode is not shown as a separate functional block as in the general diagram of FIG.

FIG. 24 is a diagram showing another use of the present invention. FIG. 24 shows a micro floppy disk of a type commonly used as a read / write medium which can be detachably attached to a computer. The disk 270 with a thin layer of magnetic material placed on the surface of a plastic substrate called a "cookie"
72 is provided rotatably. According to the present invention, a radio frequency responsive object, such as a thin dipole 278, can be incorporated on or in the disk 276 to identify the information. The diskette of FIG. 24 is similar in many respects to the card of FIG. 17 and can be mounted in a similar manner. Therefore, radio frequency responsive objects include thin dipoles having a "chuff" nature and metal-treated objects formed on the plastic disk substrate itself, which are randomly attached or placed in a predetermined spatial position. It is also possible to provide identification data using the resonance frequency of the object in addition to the spatial location. These things can be placed on the magnetic material itself,
It is also possible to arrange them on a disk. The identification data provided on such a diskette 270 includes protected data for the purpose of preventing illegal duplication of a program, or data held in a magnetic material on the diskette,
For example, radio frequency readable data can be used in encryption algorithms used to encrypt and decrypt information magnetically stored on diskettes. The use of such a diskette requires a diskette drive with both a radio frequency head and a magnetic head. Such drives can be made in a manner similar to that shown in FIGS. 16 and 18 with the necessary mechanical and other changes as appropriate for use. The application of the present invention to a computer diskette is facilitated by the fact that the diskette drive already has a read head. Providing the diskette drive with the additional capability of reading radio frequency encoded information is a relatively simple matter.

Although specific embodiments of the present invention have been described above, it will be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of functional elements of an RF / AID system.

FIG. 2 is a block diagram showing details of a radio frequency response means of FIG. 1;

FIG. 3 shows a preferred radio frequency response means.

FIG. 4 is a graph showing a method for converting numerical data into a frequency attribute.

FIG. 5 is a graph showing a distribution of a resonance frequency in a manufacturing process of the resonator.

FIG. 6 is a flowchart showing a target creation process according to the present invention.

FIG. 7 is a flowchart showing another creation process of the target creation process according to the present invention.

FIG. 8 is a graph illustrating a preferred method for generating and processing a radio frequency signal.

FIG. 9 is a block diagram showing a resonator that changes resonance characteristics to change information of a target.

FIG. 10 is a schematic diagram of a document having information encoded by the position of the resonator.

FIG. 11 is a flowchart showing a reading and writing process of information encoded on a document by a spatial position of a resonator.

FIG. 12 is a flowchart showing another reading and writing process of information encoded on a document by a spatial position of a resonator.

FIG. 13 is a flow chart following FIG. 12 showing another reading and writing process of information encoded in a document by the spatial position of the resonator.

FIG. 14 illustrates another reading and writing process of information encoded in a document by the spatial position of the resonator.
FIG.

FIG. 15 is a block diagram showing functional elements of the document reading device according to the present invention.

16 is a diagram showing an effective surface of the document reading device shown in FIG. 15 facing a document.

FIG. 17 is a front view of another document having information encoded by the spatial position of the resonator.

18 is a side view of the document shown in FIG.

19 is a diagram showing another document reading device used for reading the document shown in FIG.

20 illustrates various signals generated by reading the document of FIG. 17;

FIG. 21 is a diagram showing a tag or a target in which objects responding to a plurality of radio frequencies are arranged on a substrate.

FIG. 22 is a block diagram illustrating functions of a near-field radio frequency reading system according to the present invention.

FIG. 23 is a diagram illustrating a microwave reading system that embodies the system of FIG. 22;

FIG. 24 is a diagram showing a diskette on which radio frequency readable information is encoded.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Target 12 ... Resonator 20 ... Transmitter 30 ... Receiver 39 ... Antenna

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G06K 19/06 G06K 17/00 G06K 19/07 G06K 19/10

Claims (26)

(57) [Claims] A target for certifying the authenticity of a document arranged in a fixed array on a substrate, occupying a random spatial position on said substrate and including a plurality of thin dipoles formed from an elongated metal body. The target of claim 1, wherein the fixed arrangement of thin dipoles generates a composite radio frequency waveform associated with the document when the plurality of thin dipoles are illuminated by radio frequency energy. 2. The target according to claim 1, wherein the plurality of thin dipoles are randomly arranged in the fixed arrangement on the substrate. 3. The target of claim 2, wherein each of the thin dipoles has a random angular orientation on the substrate. 4. The target of claim 1, wherein the fixed arrangement corresponds to a disciplined arrangement of the plurality of thin dipoles on the substrate. 5. The target of claim 4, wherein each of said thin dipoles has a disciplined angular orientation on said substrate. 6. The target of claim 1, wherein said thin dipole is formed from a metallized fiber. 7. The target of claim 6, wherein the thin dipole is formed from a metalized glass fiber. 8. The target of claim 1, wherein said thin dipole is formed from aluminum. 9. The target of claim 1, wherein each of the thin dipoles resonates at an interrogation frequency having a half wavelength equal to the length of the thin dipole. 10. The target according to claim 1, wherein the substrate is selected from the group consisting of paper and plastic. 11. The target according to claim 10, wherein the thin dipole is disposed between an inner layer and an outer layer of plastic. 12. The target of claim 1, wherein the substrate has a surface area, and the plurality of thin dipoles are disposed over the entire surface area. 13. The target of claim 1, wherein the substrate has a surface area, and wherein the plurality of thin dipoles occupy only a portion of the surface area. 14. A system for proving authenticity of an object, comprising: (A) a radio frequency source illuminating the object with a signal from a radio frequency source; and (B) responding to a signal from the radio frequency source. A radio frequency detector for receiving a composite radio frequency response signal from the object; and (C) a processor coupled to the detector for determining whether the composite radio frequency response signal is a genuine response signal. A plurality of thin dipoles disposed in a fixed array of said objects, each of said thin dipoles being formed from an elongated metal body having a fixed spatial position on said object; A system comprising: a fixed array of dipoles generating the composite radio frequency response signal when the plurality of thin dipoles are illuminated by a signal from the radio frequency source. 15. The system of claim 14, wherein the plurality of thin dipoles are randomly arranged in the fixed array. 16. The system of claim 15, wherein each of said thin dipoles has a random angular orientation. 17. The system of claim 14, wherein the fixed arrangement corresponds to a disciplined arrangement of the plurality of thin dipoles. 18. The system of claim 17, wherein each of said thin dipoles has a disciplined angular orientation. 19. The system of claim 14, wherein said thin dipole is formed from a metallized fiber. 20. The system of claim 14, wherein said thin dipole is formed from aluminum. 21. The system of claim 14, wherein each of the thin dipoles resonates at an interrogation frequency having a half wavelength equal to the length of the thin dipole. 22. The system of claim 14, wherein the plurality of thin dipoles are located on a substrate of the object. 23. The system of claim 22, wherein said substrate is selected from the group consisting of paper or plastic. 24. The system of claim 23, wherein the thin dipole is located between an inner and outer layer of plastic. 25. The system of claim 22, wherein said substrate has a surface area and said plurality of thin dipoles are disposed over the entire surface area. 26. The system of claim 22, wherein the substrate has a surface area, and wherein the plurality of thin dipoles occupy only a portion of the surface area.