JP3637657B2 - Image forming apparatus, anti-counterfeiting document and ink - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus, an anti-counterfeit document, and ink suitable for use in preventing counterfeiting of banknotes, securities, and the like.
[0002]
[Prior art]
With recent improvements in the performance of color copiers, color printers, etc., there is an increased risk of counterfeiting banknotes, securities, gift certificates, entrance tickets for entertainment, and the like. In order to prevent this, image patterns such as banknotes are stored in the memory in advance, the image data of the original is collated with the contents of the memory, and if both are close, normal image output is not performed (for example, the corresponding portion (Painting black) is known. Further, a technique is known in which a dot pattern that is difficult to distinguish with the naked eye is included in the image data to be printed, and the manufacturing number of the copying machine or the like is displayed based on this pattern to facilitate tracking of the forger.
[0003]
However, it is difficult for the former technique to deal with all documents that should be prevented from forgery. In other words, the types of banknotes in circulation are limited, but the number of gift certificates, admission tickets, and the like is enormous, and it is not feasible to store all these image patterns in the memory. In the latter technique, it is easy to trace the forger after the forgery is performed, but there is a problem that the forgery itself cannot be prevented.
[0004]
By the way, a technique is known in which a metal fiber is included in a bill or the like with a predetermined distribution pattern, and the authenticity of the bill or the like is discriminated based on the metal fiber (Japanese Patent Publication No. 63-501250, Japanese Patent Laid-Open No. 6-87288, JP-A-6-79991). According to these techniques, a slit is formed across a waveguide that propagates microwaves. A bill or the like is inserted into the slit, and the transmittance of the microwave is measured. If a bill or the like is valid, the transmittance should fluctuate according to the distribution pattern, and whether the bill or the like is authentic is determined based on whether or not the variation in the transmittance is obtained.
[0005]
[Problems to be solved by the invention]
The various bills as described above are common in that the microwaves are reflected with at least some reflectivity, although the distribution patterns of the metal fibers are different. Therefore, it is considered that an original reading apparatus used in a copying machine or the like may radiate a microwave to the original in advance and read the original only when the original does not reflect the microwave.
[0006]
However, common paper is not the only material to be placed on the platen glass of a copying machine. For example, metal may be vapor deposited on the cover of a book and the title may be displayed in gold letters. For paintings, etc., gold foil may be scattered on the surface, which may require copying the printed circuit board. . In these cases, since the microwave is reflected by the metal portion of the copy, it is difficult to determine whether the copy is a forgery prevention document.
[0007]
The present invention has been made in view of the above-described circumstances. An image forming apparatus capable of accurately determining whether a copy is a forgery prevention document, and a forgery prevention document suitable for use with the image forming apparatus, and The object is to provide ink.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the configuration according to claim 1, a light source that emits light to a copy, an electromagnetic wave generating means that emits an electromagnetic wave toward the copy, and the electromagnetic wave generating means An electromagnetic wave receiving means for receiving an electromagnetic wave radiated and reflected by the object to be copied and outputting a reception level of the received electromagnetic wave; and simultaneously receiving light from the light source and an electromagnetic wave from the electromagnetic wave generating means for the object to be copied Based on the reception level output by the electromagnetic wave receiving means when radiated and the reception level output by the electromagnetic wave receiving means when only the electromagnetic wave generated by the electromagnetic wave generating means is radiated to the copy object , And determining means for determining whether or not to copy the object.
[0009]
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the copy is a document containing an optical semiconductor.
[0010]
According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the optical semiconductor has a property of increasing its conductivity when irradiated with light from the light source. The determining means determines whether or not to copy the copy based on the property.
[0011]
The anti-counterfeit document according to claim 4 is an anti-counterfeit document for determining whether or not copying is performed by the image forming apparatus according to claim 1, wherein the anti-counterfeit document is in an excited state with respect to light having a predetermined wavelength. It contains the optical semiconductor which raises.
[0015]
According to a fifth aspect of the present invention, there is provided an ink that is used for an object to be copied, which is determined by the image forming apparatus according to the first aspect, to be excited with respect to light having a predetermined wavelength. It contains an optical semiconductor whose conductivity is increased.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A. Configuration of Embodiment Hereinafter, a configuration of a document reading apparatus according to an embodiment of the present invention will be described. This document reading apparatus is used for a color copying machine.
In FIG. 1, reference numeral 1 denotes a platen glass, which is placed at a predetermined position on the glass frame 3. Reference numeral 4 denotes a glass presser, which fixes the platen glass 1 to the glass frame 3. Reference numeral 5 denotes a registration guide. On the upper surface, a position where the document 2 is to be placed is printed according to various document sizes (A4, B4, etc.). Reference numeral 6 denotes a lamp carriage which can move in parallel with the platen glass 1. Inside the lamp carriage 6, 7 is a lamp that radiates light to the document 2 via the reflection plates 8 and 8.
[0017]
This light is reflected on the document 2 and propagates along the optical axis PP ′ to the full-rate mirror 9, where it is reflected and then input to the CCD line sensor 10 via the half-rate mirror 15 and the lens 16 in order. The Reference numeral 11 denotes a transmission unit that outputs a microwave of a predetermined level, and this microwave is radiated toward the platen glass 1 by the transmission antenna 12. Here, the directivity of the transmitting antenna 12 is set so that the gain becomes the highest in the direction toward the light irradiation position (intersection of the optical axis PP ′ and the upper surface of the platen glass 1).
[0018]
Next, 14 is a receiving unit, detects the microwaves received via the receiving antenna 13, and outputs the result as the detection signal S _1. Therefore, the detection signal S ₁ has a level proportional to the RF level of the received microwave. Here, the receiving antenna 13 has the same directivity as the transmitting antenna 12, and is provided at a position that forms a line target with the transmitting antenna 12 with respect to the optical axis PP ′. Therefore, the reception level (that is, the detection signal S ₁ ) becomes maximum when the microwave is reflected from the upper surface of the platen glass 1.
[0019]
Next, the electrical configuration of the document reading apparatus will be described with reference to FIG.
In the figure, reference numeral 20 denotes a CPU which controls other components in the document reading apparatus based on a control program stored in the ROM 22. A RAM 21 is freely readable / writable by the CPU 20 and stores various variables used in the control program. An A / D converter 25 converts the detection signal S ₁ into a digital signal and supplies the digital signal to the CPU 20 via the input / output control unit 26. A main body control unit 23 controls the entire copying machine. An input / output control unit 24 exchanges various signals between the main body control unit 23 and the CPU 20.
[0020]
Next, the physical configuration of the forgery prevention document applied to this embodiment will be described. The forgery prevention document is a document containing an optical semiconductor by an appropriate method. For example, a product in which particles of an optical semiconductor are dispersed in a fiber of a document, a document in which an optical semiconductor is coated on the document, or a securities printed using an ink containing the optical semiconductor is applicable. An optical semiconductor is a substance that becomes excited when irradiated with light of the wavelength it absorbs, and increases its conductivity. When this is irradiated simultaneously with microwaves and light, the reflected wave of the microwaves The level increases.
[0021]
This embodiment utilizes this property. In other words, by comparing the level of the reflected wave between the case where microwaves are radiated to a copy object during copying and the microwave and light are emitted simultaneously and the case where only microwaves are radiated, an optical semiconductor is applied to the copy object. Can be determined. If the object to be copied contains an optical semiconductor, it is an anti-counterfeit document, and in this case, copying is stopped.
[0022]
As the optical semiconductor used for the anti-counterfeit document, either an inorganic semiconductor or an organic semiconductor can be used as long as it has a spectral sensitivity corresponding to the light source used for anti-counterfeiting. As the inorganic semiconductor, various materials used for inorganic photoreceptors for copying machines can be applied, and specific examples include the following substances.
[0023]
(1) Group VI such as Se and Te and compound semiconductors thereof.
(2) Group IV such as Si, Ge, Sn, and compound semiconductors thereof.
(3) III-V group such as GaAs and InP, and compound semiconductors thereof.
(4) II-VI groups such as ZnO, ZnSe, CdS, and compound semiconductors thereof.
These can be applied to either crystal or non-crystal.
[0024]
As the organic semiconductor, various organic semiconductors applicable to so-called OPC (organic photoreceptor) can be applied, and specific examples include the following compounds.
(1) Azo pigments such as monoazo pigments, bisazo pigments, trisazo pigments and tetrazo pigments.
(2) Perylene pigments such as perylene acid anhydride and perylene imide,
(3) Polycyclic quinone pigments such as anthraquinone derivatives, anthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives, and isoviolanthrone derivatives.
(4) Indigo pigments such as indigo derivatives and thioindigo derivatives.
(5) Metal phthalocyanine pigments such as copper phthalocyanine and titanyl phthalocyanine.
(6) Carbonium pigments such as diphenylmethane pigments, triphenylmethane pigments, xanthene pigments, acridine pigments.
(7) Quinone imine pigments such as azine pigments, oxazine pigments and thiazine pigments.
[0025]
(8) Methine pigments such as cyanine pigments and azomethine pigments.
(9) Quinoline pigments.
(10) Benzoquinone and naphthoquinone pigments.
(11) Naphthalimide pigments.
(12) Perinone pigments such as bisbenzimidazole derivatives.
(13) Azurenium pigment.
(14) Squarelium pigments.
(15) A eutectic complex formed from a pyrylium / thiapyrylium dye and a polycarbonate compound.
(16) Electron-donating compounds having electron-accepting substituents such as nitro, nitroso and cyano groups, and electron-donating substituents such as amino, phenyl, alkyl and heterocyclic groups Charge transfer complexes with compounds.
[0026]
Among these, azo pigments, perylene pigments, polycyclic quinone pigments, and phthalocyanine pigments are particularly preferable because of their excellent photoconductivity and weather resistance. Since these are also colored materials, when they are used as paints or inks, those having a desired color may be selected. When using, you may use together with the coloring material which does not have photoconductivity. When these are used as paints or inks, they are dispersed in an appropriate binder resin, but in the case of cards, they may be dispersed directly in the base plastic material (the dispersion ratio is relative to the binder resin or base plastic material). 5 to 100% by weight is preferred).
[0027]
Here, the wavelength of the light that excites the optical semiconductor differs depending on the type of the optical semiconductor. Therefore, if the type of the optical semiconductor is selected so that this wavelength matches the wavelength of the light generated by the lamp 7, the optical semiconductor can be excited by the lamp 7. That is, it is not necessary to provide a new light source to excite the optical semiconductor.
[0028]
B. Operation of Embodiment Next, the operation of this embodiment will be described.
First, when the start button is pressed in the copying machine main body, the main body control unit 23 issues a document reading command to the CPU 20. When receiving this command, the CPU 20 activates the program shown in FIG. When processing is started in the figure, the lamp carriage 6 is moved to the origin (position where the full-rate mirror 9 comes directly below the registration guide 5) in step SP1. Next, the lamp 7 is turned on, and “0” is substituted into the variables CT and XCT. Then, the microwave is transmitted via the transmission unit 11 and the transmission antenna 12.
[0029]
Next, when the process proceeds to step SP2, the lamp carriage 6 is moved at a constant speed in the sub-scanning direction (right direction in FIG. 1) by a predetermined length (for example, about several mm). During this period, the light radiated from the lamp 7 is reflected through the reflection plates 8 and 8, the document 2, and the full rate mirror 9 and input to the CCD line sensor 10. The CCD line sensor 10 outputs image data according to the intensity of the input light. The receiving unit 14 detects the received microwave and outputs a detection signal S ₁ . Next, when the process proceeds to step SP3, it is determined whether or not the current position of the lamp carriage 6 is a predetermined scan end position.
[0030]
Here, processing is determined to be "NO", the flow proceeds to step SP4, the detection signal in S ₁ is variable LF [CT] (SEQ LF elements CT. This specification, "Factors Y sequence X", "Variables X [Y] ”). Since the variable CT is initially set to “0” in step SP1, the detection signal S ₁ is substituted into the variable LF [0] here. Next, when the process proceeds to step SP5, the variable CT is incremented by “1”. When the above process ends, the process returns to step SP2.
[0031]
Next, in step SP2, the lamp carriage 6 is again moved at a constant speed in the sub-scanning direction by a predetermined length. Then, the process through the step SP3 is proceeds to step SP4, the variable LF [CT] (variable LF [1]) detection signals S ₁ is substituted into. Similarly, the lamp carriage 6 is moved in the sub-scanning direction by a predetermined length, and the detection signal S _{1 at} each part is sequentially substituted into a variable LF [CT] (CT = 0, 1, 2,...).
[0032]
Then, when the process proceeds to step SP3 after the lamp carriage 6 reaches the scan end position, “YES” is determined here, and the process proceeds to step SP6. The value of the variable CT at this time is hereinafter referred to as “CT _MAX ”. As in the known copying machine, the light incident on the CCD line sensor 10 until the lamp carriage 6 reaches the scanning end position is sequentially converted into image data, and an image memory (not shown) in the copying machine main body. Will be accumulated.
[0033]
Here, the configuration of the document 2 is shown in FIG. In the figure, reference numeral 2a denotes a forgery prevention document, which is a rectangular paper in which an optical semiconductor is dispersed. Security document 2a is at the time of turning on the lamp 7 has a microwave reflectance enough to detection signals S ₁ greater than a predetermined value L _a is obtained, at the time of extinction of the lamp 7 predetermined value L _b (where L _a> L _b ) It has a microwave reflectivity enough to obtain the following detection signal S ₁ . Further, 2b is plain paper coated metal film, which formed by fixing a metal foil on unevenness distribution on the surface of the plain paper, the extent to which the detection signals S ₁ comparable to the predetermined value L _a is obtained micro It has wave reflectivity.
[0034]
Further, 2c is a metal plate having a high microwave reflectivity, the detection signals S ₁ regardless on / off state of the lamp 7 is higher than the predetermined value L _a. 2d is plain paper, has a low microwave reflectance, and the detection signal S ₁ becomes lower than the predetermined value L _b regardless of whether the lamp 7 is turned on or off. The document 2 is configured by sequentially arranging these units (2a to 2d). Therefore, when the document 2 by the lamp carriage 6 is scanned, the detection signals S ₁ is as shown in FIG. 4 (a), the variable LF [CT] sampling results of the detection wave signal S ₁ is stored.
[0035]
Now, returning to FIG. 3, when the process proceeds to step SP6, the lamp 7 is turned off. Next, when the process proceeds to step SP7, it is determined whether or not the variable LF [CT] (currently the variable LF [CT _MAX ] last set in step SP4) exceeds _a predetermined value La. According to the graph of FIG. 4 (a), the time t ₄ after the detection signal S ₁ (and corresponding variable LF [CT]) is always less than the predetermined value L _a. Therefore, it is determined as “NO” here, and the process proceeds to Step SP12. Here, the lamp carriage 6 is returned by a predetermined distance (same distance as the distance scanned in step SP2) toward the origin, and the variable CT is decremented by “1”.
[0036]
Next, when the process proceeds to step SP13, it is determined whether or not the lamp carriage 6 has been returned to the origin. Since it has not yet returned at this time, it is determined as “NO”, and the process returns to step SP7. Thereafter, the loop of steps SP7, SP12 and SP13 is repeated, and each time step SP12 is executed, the lamp carriage 6 returns to the origin by a predetermined distance, and the variable CT is decremented. Even during such processing, microwaves are radiated through the transmission unit 11 and the transmission antenna 12, and the detection signal S ₁ corresponding to the reception level is output from the reception unit 14. The level of the detection signal S ₁ is shown in FIG. 4 (c) corresponding to FIGS. 4 (a) and 4 (b).
[0037]
Thus, the step SP12 is repeatedly performed, finally the lamp carriage 6 reaches the portion of the metal plate 2c, the detection signal S ₁ is rapidly increased. Immediately shown in FIG. 4 (c) At time t _7, which is in such a state. Subsequently, when the process returns to the step SP7, the magnitude relationship of the variable LF [CT] and the predetermined value L _a are compared. Variable LF [CT] at this time is obtained by sampling the detection signals S ₁ immediately before the 4 time t ₄ of (a), has a higher level than the predetermined value L _a. Therefore, it is determined “YES” here, and the process proceeds to step SP8.
[0038]
In step SP8, the detection signals S ₁ is or less than a predetermined value L _b is determined. As described above, at this point in time, the detection signal S ₁ rises and is higher than the predetermined value L _b , so it is determined “NO” here, and the process proceeds to step SP12. Thereafter, the loop of steps SP7, ₈ , 12, and 13 is repeated until time t8 is reached.
[0039]
Next, in a period of time t ₈ ~t _9, for the variable LF [CT] corresponding to the metal foil plain paper 2b, it is sequentially executed the determination of the sequential steps SP7. As described above, the metal foil plain paper 2b has a microwave reflectance enough to detection signals S ₁ comparable to the predetermined value L _a is obtained. However, in practice due to the effect of such unevenness and noise of the metal foil, the variable LF [CT] varies around the predetermined value L _a. Accordingly, the determination result in step SP7 also varies accordingly. However, in this period, detection signals S ₁ is always at a higher level than the predetermined value L _b.
[0040]
Accordingly, if “NO” is determined in step SP7, the process directly proceeds to step SP12. However, even if “YES” is determined, “NO” is determined in step SP8, and the process proceeds to step SP12. Eventually, in either case, the process proceeds to step SP12, and each time step SP12 is executed, the lamp carriage 6 returns toward the origin by a predetermined distance. As described above, the difference between the predetermined values L _a and L _b is set to be equal to or larger than the error width due to general noise or the like.
[0041]
Then, at time t ₉ after the period, for a variable LF [CT] corresponding to security document 2a, the determination in step SP7 is executed. Since these variables LF [CT] are obtained by sampling the detection signal S ₁ during the period (time t _{1 to} t ₂ ) during which the optical semiconductor is excited, it is determined as “YES” in step SP7. On the other hand, since the lamp 7 is turned off at this time and the optical semiconductor is not excited, “YES” is determined also in step SP8, and the process proceeds to step SP9.
[0042]
In step SP9, the variable XCT is incremented by “1”. Since the variable XCT has been previously reset to “0” in step SP1, it becomes “1” when step SP9 is first executed. Next, when the process proceeds to step SP10, it is determined whether or not the variable XCT has reached a predetermined limit value LIM. If "NO" is determined here, the process returns to step SP7 via steps SP12 and SP13.
[0043]
According to FIG. 4 (a) ~ (c) , the variable LF [CT] corresponding to security document 2a is always not less than the predetermined value L _a, the detection signals S ₁ is always less than the predetermined value L _b. Accordingly, thereafter, a loop composed of steps SP7 to SP10, 12, and 13 is repeatedly executed. Each time step SP9 is executed, the variable XCT is incremented by “1”. Each time step SP is executed, the lamp carriage 6 returns toward the origin by a predetermined distance. Then, when the variable XCT eventually exceeds the limit value LIM, the process proceeds to step SP11.
[0044]
Here, a command is output from the CPU 20 to the main body control unit 23 so as to take a forgery prevention measure. Here, the “counterfeit prevention measure” may be various types such as, for example, flashing the image memory to output a blank sheet, painting the sheet black, and not outputting the sheet itself. In short, any measure may be used as long as the user cannot obtain a normal copy. Here, the reason why the “counterfeit prevention measure” is taken only when the variable XCT exceeds the limit value LIM is that “the anti-counterfeiting measure” is taken due to dust adhering to the document 2 or a large noise temporarily on the detection signal S _1. This prevents the “counterfeit prevention measures” from being performed. Therefore, the limit value LIM may be set to a value that can detect small securities (for example, postage stamps).
[0045]
If the document 2 does not contain the forgery prevention document 2a, the lamp carriage 6 returns to the origin without the variable XCT reaching the limit value LIM. When step SP13 is subsequently executed, “YES” is determined, and the process proceeds to step SP14. Here, the CPU 20 instructs the main body control unit 23 to perform image output. When the main body control unit 23 receives this command, it prints the image data in the image memory on paper and outputs it.
[0046]
In the above embodiment, the light source used for determination of the forgery prevention document is used in combination with the light source used for reading the document. However, it goes without saying that the light source used for determination of the forgery prevention document may be provided separately. In this case, the degree of freedom of copy prohibition can be increased in that the light source can be selected in accordance with the original for which copy prohibition is desired.
[0047]
【The invention's effect】
As described above, according to the present invention, whether or not to copy a material to be copied is determined based on the reception level of the reflected wave in both states when the microwave and light are emitted simultaneously and when only the microwave is emitted. Therefore, it is possible to accurately determine whether or not the copy is a forgery prevention document.
[Brief description of the drawings]
FIG. 1 is a front view of an original reading apparatus according to an embodiment.
FIG. 2 is a block diagram of the embodiment.
FIG. 3 is a flowchart of a control program according to the embodiment.
FIG. 4 is an operation explanatory diagram of the embodiment.
[Explanation of symbols]
7 Lamp (light source)
11 Transmitter (electromagnetic wave generating means)
12 Transmitting antenna (electromagnetic wave generating means)
13 Receiving antenna (electromagnetic wave receiving means)
14 Receiver (Electromagnetic wave receiving means)
20 CPU (determination means)

Claims (5)

A light source that emits light to the copy;
Electromagnetic wave generating means for radiating electromagnetic waves toward the material to be copied;
An electromagnetic wave receiving means for receiving an electromagnetic wave radiated from the electromagnetic wave generating means and reflected by the object to be copied, and outputting a reception level of the received electromagnetic wave;
When the light from the light source and the electromagnetic wave from the electromagnetic wave generation means are simultaneously emitted to the copy object, only the reception level output by the electromagnetic wave reception means and the electromagnetic wave from the electromagnetic wave generation means to the copy object An image forming apparatus comprising: a determination unit that determines whether or not to copy the copy based on a reception level output from the electromagnetic wave reception unit when the electromagnetic wave is radiated .   2. The image forming apparatus according to claim 1, wherein the copy is a document containing an optical semiconductor. The optical semiconductor has the property of increasing its conductivity when irradiated with light from the light source,
3. The image forming apparatus according to claim 2, wherein the determination unit determines whether or not the copy of the object is to be copied based on the property. An anti-counterfeit document for determining whether or not to copy by the image forming apparatus according to claim 1,
An anti-counterfeit document characterized by containing an optical semiconductor that is in an excited state with respect to light of a predetermined wavelength and has increased conductivity. An ink used for a copy to be copied by the image forming apparatus according to claim 1,
An ink comprising an optical semiconductor that is excited with respect to light of a predetermined wavelength and has increased conductivity.

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