Paper Document Validation Apparatus

Abstract

An apparatus for detecting authenticity of paper currency or documents being printed with intaglio type printing so that the printing raises bumps or contours on the surface of the document. Authentication is made by detecting a predetermined section of the document which has uniformly spaced bumps or contours from the surface thereof commonly formed by parallel uniformly spaced lines by some type of mechanical transducer, normally in the configuration of a vertically sensitive phonograph needle. Relative movement is provided between the needle and the document at a uniform speed so that an audio frequency is detected by the needle moving over the bumps or contours. If the audio frequency is within a proper band, it actuates an audio sensitive reed. The vibration of the reed closes a circuit that indicates authentication and payout, or any other output signal is then generated.

Description

PRIOR ART

There are many ways now in use to establish the validity of paper currency or documents, and they range from the use of magnetics, to actual measurement by infrared radiation of ink thickness, which is the technique described in my U.S. Pat. No. 3,457,421. In the course of experimentation in the field of paper currency validation, my efforts have been directed to the end of establishing that the document has been printed by the intaglio process, and has a thick layer of ink. In this intaglio process, the ink is carried beneath the surface of the printing plate, in grooves cut by hand or machine, and thus is capable of providing a heavy layer of ink on the document or currency, and hence a bump or measurable contour. This is in direct contrast to the type of printing obtained with reproducing machines, or by letter press or offset processes, where there is no appreciable or measurable ink buildup.

Attempts have been made in the past by the petitioner to utilize the printed information on the surface of the document by scanning it or scratching it, or the like. My prior art techniques suffer from their complete inability to differentiate the signal from the noise of scratching the paper, relative movement of the parts, etc. In other words, proper signal to noise ratios to obtain any worthwhile signal information has been substantially impossible. To the best of my knowledge, no one has ever provided a successful electromechanical transducer readout to indicate validation of U.S. paper currency, or any document printed by the intaglio printing process.

Therefore, it is the general object of my invention to provide an apparatus utilizing an electromechanical transducer to provide document validation for documents printed with the intaglio printing process, or having sufficiently raised ink characteristics on the surface of the document that such characteristics can be detected with a suitable electromechanical transducer.

These and other objects of my invention are achieved by providing an apparatus to detect authenticity of paper documents having at least one section of uniformly spaced surface unevenness which comprises a frame defining a testing area, electromechanical transducer means positioned within the testing area adapted to engage the document entering therein, means to carry a document and effect relative uniform movement between the document and the transducer means in the testing area, means to generate an audio frequency signal from the engagement of the document by the transducer means during the relative movement therebetween, and an audio frequency sensitive switch actuated by the proper signal from the transducer means to indicate an authentication.

For a better understanding of the invention reference should be had to the accompanying drawings wherein:

FIG. 1 is a block diagram schematic illustration of the structural and circuit components necessary to achieve operation of the preferred embodiment of my invention;

FIG. 2 is a greatly enlarged illustration of the surface area of a document printed by the intaglio process and showing the relationship of the electromechanical transducer to the bumps and contours on the surface thereof; and

FIG. 3 is a view of a piece of paper currency illustrating the probable areas of the currency where the electromechanical transducer will engage the document to measure uniformly spaced lines.

In effect, the objects of the invention are achieved by combining a simple phonograph cartridge with a predetermined uniform relative motion of the paper currency being examined to the cartridge, with an extremely high "Q" electromechanical filter, known as a resonant reed relay. Utilizing these elements as described hereinbelow, I find it possible to determine accurately that a document is of the precise design, and is printed by the intaglio process, and may be assumed to be genuine with a high order of security. The device described hereinafter with relation to the drawings is of value in many instances where my infrared technique defined in my U.S. Pat. No. 3,457,421 may lack definition due to an absence of absorption of infrared radiation in some transparent inks. My device described hereinbelow is applicable to well over 95 percent of higher denominations of paper currency now in use throughout the world.

With reference to the embodiment of the invention shown in FIG. 1 of the drawings, the numeral 10 indicates a document-carrying frame which is driven between fixed stops 12 and 14 by engagement with a screw 16 rotatably driven by a motor 18. Any other suitable mechanism to effect relative movement of the frame 10 would meet the objects of the invention. Appropriate microswitches 20 and 22 engage with the stops 12 and 14, respectively, upon movement of the frame 10 to either stop or reverse the drive of motor 18 as selectively desired to control the translating movement of frame 10 with respect to the screw 16. The motor 18 is preferably of the synchronous type and is driven from an appropriate alternating current source 24 so that the movement of frame 10 is as nearly uniform as possible between the stops 12 and 14.

I contemplate that any suitable structure to support a document 30 on the top of frame 10 as by engaging with a suitable bed 32, for example, would be satisfactory. However, a tray, slide, or other bill-accepting mechanism to be carried by frame 10 would work quite satisfactorily.

The objects of the invention are achieved by mounting an electromechanical transducer 34, such as a phonograph cartridge, for example, which is of the vertical responsive type, or one for playing hill and dale recordings so that a transducer pickup 36 carried on arm 38 will engage with the surface of document 30 lightly in the manner of a phonograph needle with a record, as the document 30 moves beneath it upon the translation of frame 10 between stops 12 and 14.

For the purposes of illustration, assume a speed of frame 10 of about 3 inches per second, and a line repetition rate on the document 30 of 100 lines per lineal inch, the cartridge 34 will present a signal to an amplifier 40 of 300 Hz. This signal upon proper amplification drives a relay coil 42. A reed of spring steel or other magnetically affected material, which has a mechanically resonant period of 300 Hz., and is indicated by numeral 44, is appropriately suspended near coil 42 as illustrated. Due to its natural predetermined period of 300 Hz., the reed 44 will be readily excited into resonance by a 300 Hz. signal induced into coil 42. This type of reed 44 is not readily effected by any other frequency, except frequencies of extremely high amplitude. Typically, such a reed can be made to resonate at a center frequency of plus or minus 1 Hz. It can also reject other frequencies of extreme amplitudes, when they are displaced as little as 3 to 5 Hz. from the center frequency. A reed of this type is available to the public, and a typical reed would be one made by W. S. Deans Co. of Gardena, Calif.

This resonant vibration of reed 44 then causes reed 44 to impinge on contact 46 closing an electrical circuit through lines 48 and 50 to properly actuate a payout or authentication apparatus indicated by block 52. It should be understood that any suitable device can be actuated by the closing of the circuit between wires 48 and 50 by the vibration of reed 44 and its engagement with contact 46.

FIG. 2 illustrates a greatly enlarged view of the security 30 showing the raised bumps or contours 30a on the surface thereof. Preferably, the measurement of these raised bumps is in the portrait background section indicated by numeral 31 in FIG. 3 as the bumps caused by the lines in this background section are uniformly spaced and parallel to each other. I have found that the needle of the electrotransducer pickup 36 very easily slides over the contours or bumps 30a and because of its vertical responsive characteristics, will provide pronounced peak signals and an extremely accurate frequency determination as the document 30 is moved at a uniform speed with relation thereto. I have also found that I can measure either the vertical or horizontal lines in the portrait background section of U.S. paper currency, for example, by effecting the relative movement in either the vertical or horizontal direction between the document and the transducer needle pickup. I have found that exact registration with a particular path with respect to the document is not necessary as I allow some floating relationship of the cartridge 34 and needle 36 so that it tends to center itself between the lines which run parallel to the direction of movement of frame 10 so as not to be disturbed by those lines, but to center itself and only read those lines which extend transversely to the direction of movement of the needle 36 with respect to the document 30.

Thus, it should be seen that the objects of my invention have been achieved by providing a frequency pickup with an electromechanical transducer achieved by the uniform movement of a document with respect to the transducer, or vice versa. An extremely high signal to noise ratio is possible because the tone causes resonant vibration of a predetermined reed of steel suspended near the coil. The vibration of the reed of steel will only occur if the frequency generated is within a predetermined bandwidth. Hence, an extremely high signal to noise ratio is achieved. The vibration of the reed closes the circuit and indicates an authentication.

While in accordance with the patent statutes only the best known embodiment of the invention has been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby, but that the inventive scope is defined in the appended claims.

Claims

What I claim is:

1. Apparatus to detect authenticity of paper documents having at least one section of uniformly spaced surface bumps or contours, which apparatus comprises

a frame defining a testing area,

electromechanical transducer means positioned within the testing area adapted to engage the surface of a document entering therein and produce a signal indication thereof,

means to carry a document and effect relative uniform movement between the document and the transducer means in the testing area,

means to generate an audio frequency signal from the signal indication of the transducer means, and

an electromechanical filter including an audio frequency sensitive switch actuated by a proper frequency signal from the last said means to indicate an authentication.

2. Apparatus according to claim 1 where the means to carry the document and effect relative uniform movement comprises a document-carrying frame, a screw threadably received by the frame, motor means to rotatably drive the screw to effect translational uniform movement of the frame relative to the screw, and means to effect reversible control and stopping action of the motor occasioned by the movement of the frame.

3. An apparatus according to claim 1 where the electromechanical transducer means is a piezoelectric needle pickup which includes an amplifier to effect amplification of the electrical signal from the piezoelectric needle pickup.

4. Apparatus to detect authenticity of paper documents having at least one section of uniformly spaced surface bumps or contours, which apparatus comprises

a frame defining a testing area,

electromechanical transducer means positioned within the testing area adapted to engage the surface of a document entering therein and produce a signal indication thereof,

means to carry a document and effect relative uniform movement between the document and the transducer means in the testing area,

means to generate a frequency signal from the signal indication of the transducer means, and

a frequency sensitive switch actuated by a proper frequency signal from the last said means to indicate an authentication, the frequency-sensitive switch being a reed which has a mechanical resonant period so as to be readily excited into resonance by a proper frequency signal.

5. An apparatus according to claim 4 where the reed is made of spring steel, and its natural predetermined period of resonance is determined by the rate of relative movement between the document and the piezoelectric pickup needle, and the spacing of the lines in the portrait background section of the type document which is to be engaged by the pickup needle.

6. Apparatus to detect authenticity of a test article having at least one section of uniformly spaced bumps or contours on the surface thereof which are at least slightly raised with respect to the surface thereof which comprises a frame to carry a test article, an electromechanical transducer means having a pickup needle adapted to engage the surface of the test article, means to effect relative uniform movement between the frame and the transducer means to have the pickup needle pass over the uniformly spaced bumps or contours on the surface of the test article to generate an electrical frequency signal indication of the lines, means to amplify the frequency signal, and a filter actuated only by a proper frequency signal from the signal amplification generation means operatively connected thereto to indicate an authentication.

7. Apparatus according to claim 6 and where said filter includes a coil means receiving said amplified signal, and a frequency selective switch operatively connected to said coil means.

8. Apparatus according to claim 6 where the filter includes a metal reed which has a mechanical resonant period so as to be readily excited into resonance by a proper frequency signal.