JPS6331834B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a printed matter discriminating device that discriminates whether a printed matter is correct or not while conveying it.

(Prior art) When determining whether a printed matter is correct or not, a common method is to focus on the characteristics of metallic elements (magnetism) and hue contained in the printing ink, and to determine whether these characteristics exist or not and by comparing with a reference amount. It is. The simplest method would be to consider the above-mentioned characteristics for the entire printed matter as a macroscopic detection amount, but in order to perform high-performance discrimination, it is necessary to divide the printed material into multiple parts and calculate the detection amount for each classification. It is necessary to consider it as a microscopic detection amount and to judge whether it is correct or not based on the similarity and degree of matching with the reference pattern.

Conventionally, for example, a method is known in which features are detected by moving a printed matter relative to a fixed detection head while running the printed material in a fixed direction. If you want to detect this feature as a divided pattern on the print surface, place a print detection element such as a photoelectric switch close to the detection head, and from the moment the print reaches the detection element, the number of divisions N will be detected. one of them
A method has been used in which a timer is operated to set a time T for the sorting area to pass through the sensing head, and the sorting signal is generated N times at every time T while the printed matter passes through the sensing element.

Here, as a conventional example, the distribution pattern of a metal element, such as iron (Fe), contained in printing ink is detected using a fluorescent X-ray method, the degree of agreement with a reference pattern is calculated, and the degree of agreement is determined to a certain degree. If it gets hot,
A device for determining authenticity will be explained.

Figure 1 shows the overall block diagram. First, an outline of the discrimination method will be described with reference to FIG.

A fixed area of printed matter 101 is irradiated by an X-ray generator 103 while being conveyed in the direction of the arrow by a conveyor belt 102 . If a metal element is present in the printed material, fluorescent X-rays are generated at a wavelength λ unique to the metal element and with an intensity proportional to the density of the metal element. This fluorescent X-ray is detected by an X-ray detector (proportional counter) 104.
When converted into an electrical signal, a pulse signal with a wave height corresponding to the contained element and a number compared to the contained density is obtained. After this pulse signal is amplified to an appropriate amplitude by a pulse amplifier 105, a pulse height discriminator circuit 106 discriminates only the pulse signal P1 having a pulse height corresponding to a specific element, in this case iron (Fe). Therefore, the pulse P
1 is counted by the data counter 107 for a certain period of time T, and the value P2 is that the printed matter is
04 for time T, length S=(V・T,
V is the density of Fe contained in the area (conveying speed). Therefore, the printed matter is the X-ray detection detector 1.
While passing through 04, count repeatedly at time T,
If the data is sequentially stored in the data register 108, the Fe element distribution pattern signal P3 obtained by dividing the print surface into N (=L/S, L is the length in the transport direction of the print)
is obtained.

A reference pattern signal P4 obtained by dividing genuine printed matter into N categories is stored in the reference pattern memory 109 in advance, and after the printed matter has passed through the detection head 104, it is read out at the same time as P3 under the control of the discrimination control circuit 110, and a match is made. A degree calculation circuit 111 obtains a degree of coincidence P5. The determination circuit 112 outputs a determination signal indicating authenticity when P5>PS (PS is the determination level) holds true. Here, the degree of matching is determined by N
Let it represent the difference |P3()−P4()|(=1 to n) between the division pattern signal P3 and the reference pattern signal P4.

Next, a method for dividing printed matter into N categories will be described. Division signal generation circuit 1 that generates a clear pulse CR to the data counter 107 and a shift pulse SP to the data register 108 in FIG.
Thirteen conventional examples are shown in FIG. The photoelectric switch 115a in FIG. 1 is placed close to the detection area of the detection head 104, facing the lamp 114a, and its output T2 normally outputs "0", and outputs "1" while the printed matter 101 is passing through. Output. Printed matter 10
At the moment when 1 reaches the photoelectric switch 115a, T2 rises from "0" to "1", and the differentiating circuit 203 generates a thin pulse S1 to clear the counter 204. AND circuit 202 passes the clock pulse CP of oscillator 201 while the printed matter is passing through.
A counter 204 counts the clock pulses CP and outputs a shift pulse SP every time a certain value is reached. The period T of the shift pulse SP is 10 times the printed matter.
1 is the time to move S (=V·T, V is the transport speed of the printed material), and S corresponds to the length of one divided area in the transport direction.

The shift circuit 205 delays the shift pulse SP by several clock pulses CP.
Outputs clear pulse CR to 07. The shift pulse SP and the clear pulse CR are continuously outputted while the printed matter passes over the photoelectric switch 115a, and as a result, the data register 108 stores S as 1.
Fe distribution pattern signals of N sections having a section area length are accumulated and compared and judged with the reference pattern signal using the above-mentioned judgment method.

However, in a printed material discrimination device that has such sorting means, if the conveying speed changes from a predetermined speed due to changes in time, temperature, humidity, power supply, etc., it must be detected every time even if the printed material is of the same type. It becomes difficult to accurately determine the divided areas, and it becomes impossible to match them with the reference pattern. (Changes in conveyance speed mentioned here are generally long-term changes.) Even if the printed matter is genuine, if the size differs from the standard due to shrinkage, etc., the detected classification area may be divided into predetermined classifications. A deviation occurs with respect to the area, and as a result, the signal does not match with the reference pattern signal, resulting in misjudgment. This situation is shown in FIG. 4b. The solid line P3 is the Fe distribution pattern signal when a genuine printed matter with regular dimensions is conveyed at a predetermined speed vm/s, and the dotted line P3' is a signal when a genuine printed matter is shortened due to shrinkage or when the conveying speed is increased. It is. As is clear from the figure, even though both are genuine printed materials, deviations occur in the Fe distribution patterns and the discrimination performance deteriorates.

As a means for performing classification unaffected by changes in conveyance speed, it is conceivable to use a tachogenerator or the like that generates pulses with a period synchronized with a conveyor belt drive roller (not shown) in place of the generator 201 in FIG. It is expensive, has a bad space factor, and cannot eliminate the deviation of the divided areas due to dimensional changes in the printed matter itself, so it is not practical.

(Problems to be Solved by the Invention) As described above, according to the conventional apparatus, the generation interval of shift pulses for classifying information from printed matter was fixed, so that the conveyance speed was set at a predetermined speed. If the size changes, or if the printed matter shrinks and deviates from the standard size, it will no longer match the standard pattern, resulting in a disadvantage that accurate determination of authenticity cannot be performed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a printed matter discriminating device that can inexpensively and accurately discriminate printed matter even if the conveyance speed or the length of the printed matter varies from a specified value.

[Structure of the Invention] (Means for Solving the Problems) The present invention detects the distribution of magnetic substances contained in printed matter, the printed pattern, or In a device that sequentially stores information such as hue distribution in a register and determines whether the printed matter is correct or not, or the type, etc. from this pattern information, a classification signal generation means for classifying information to the register for each divided area on the surface of the printed matter. and means for detecting a transit time determined in advance by the conveyance speed and length of the printed matter before the printed matter to be inspected reaches the detection head, and the classification signal generating means is provided with a means for detecting a passing time determined by the conveying speed and length of the printed matter before the printed matter reaches the detection head. This method is characterized in that the generation interval of the classification signal is determined based on the transit time.

(Function) When the present invention conveys a printed matter onto a conveyance path and detects pattern information on the surface of the printed matter from a detection head for each section area to determine whether the printed matter is correct or not, the present invention determines the transit time of the printed matter to the detection head prior to detection. By determining the generation interval of the classification signal that classifies the pattern information from the detection head according to the measured value, it is possible to always accurately match the reference pattern even if the conveyance speed fluctuates or the print itself shrinks. It is for making a judgment.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 3 shows an embodiment of the division circuit according to the present invention, which replaces the conventional division circuit shown in FIG. Furthermore, as shown in the block diagram of FIG. 1, a new set of photoelectric switch 115b and lamp 114b is added compared to the conventional one. FIG. 4a shows signal waveforms at each part.

The photoelectric switches 115a and 115b are the lamps 11
4a and 114b, and the output Ta,
T1 is normally "0" and outputs "1" while the printed material 101 passes through. The photoelectric switch 115b is placed on the conveyance path at a distance sufficiently far from the photoelectric switch 115a than the length of the maximum printed material. AND circuits 301 and 302 are photoelectric switches 115a and 11
While the printed matter 101 is passing through the generator 3
The pulse CP generated by 03 is counted by the counter 307, 3.
Sent on 04. Therefore, the counter 304 counts the time it takes for the printed matter 101 to pass through the photoelectric switch 115b, and takes the value as M. The division circuit 305 divides the count value M of the counter 304 by the number of divisions N and stores the resulting value Z (M/N) in the register 306. The count value of the counter 307 is the printed matter 101
While passing through the photoelectric switch 115a, that is, while leaving the detection field of view,
Each time it reaches the stored value Z of 6, it outputs a shift pulse SP to the data register 108, returns the count value to zero, and continues counting anew. The counter clear pulse CR is sent to the shift register 308.
This is a signal obtained by delaying the shift pulse SP by several clock pulses CP. N shift pulses SP and N counter clear pulses CR are each output. After the data counter value P2 is divided and stored in the data register 108 by the shift pulse SP, the data counter 107 is cleared by the counter clear pulse CR and new data is counted. This is repeated N times, and the data register 108 is divided into N sections.
Fe pattern is accumulated.

The above is for printed matter of regular length, and the fourth
In the waveform diagram in Figure a, all lines are shown as solid lines. On the other hand, the waveform for shrunk printed matter or when the conveyance speed increases above the specified speed is shown by a dotted line.
becomes the count value M′ (M′<M), and the division value Z′(=M′/
N), which is shorter than the period for printed matter of regular length, but it still generates N shift pulses SP' and counter clear pulse CR', and the data counter 10
7 output P2', data register 108 output P
3' is obtained. In other words, even if it is a shrunken printed matter,
Further, even printed matter whose conveyance speed is changing is classified into N pieces like regular printed matter.

This effect will be explained using FIGS. 4b and 4c.

Figure 4b shows the shift pulse SP generated using the conventional classification method and the P obtained from the counter clear pulse CR.
3, P3' pattern. As is clear from the figure, the pattern P3' of the shrunken print disappears at the rear and the phase is also shifted, so that even if it is a genuine print, the degree of coincidence with the regular pattern P3 becomes small.

FIG. 4c shows the pattern of P3 and P3' obtained from the shift pulse SP and counter clear pulse CR generated by the method according to the present invention. As is clear from the figure, there is no difference in the values in each category from the regular printed matter even for the shrunken printed matter, and the degree of agreement increases.
Authentic discrimination results can be obtained. On the other hand, even if the conveyance speed changes, the same effect can be obtained; for example, if the conveyance speed becomes faster, this is equivalent to shrinking the printed matter, so it can be processed in the same way.

In the embodiment, a shrunken printed matter has been described, but the same effect can be obtained even when a stretched printed matter is used. Furthermore, even if there are a plurality of printed matter having different lengths, if all N-divided Fe distribution patterns are to be detected, only one division circuit is required, and the circuit configuration can be simplified.
In this case, the reference pattern memory is required for the number of types of printed matter.

Furthermore, although the embodiment deals with the Fe distribution pattern, it goes without saying that other detection patterns such as hue may also be used.

Further, in the embodiment, the test material is divided into equal N divisions, but it is also possible to divide the printed material to be inspected into areas of arbitrary ratios. For example _, as _{shown in} FIG _.
A case where detection is performed by dividing into areas (N ₂ and N ₃ are natural numbers) will be explained using FIG. 3 and FIG. 6a. In FIG. 6a, 601 to 603 are the third
Corresponds to 305 to 307 surrounded by dotted lines in the figure, 601 is a divider, 602 is a register, 603
is a counter. This register 602 can store multiple values. The division circuit 305 in FIG. 3 divides the count value M by the number of sections N, but in this embodiment, the division circuit 601 divides the count value M by Wi=
Ni/(N ₁ + N ₂ + N ₃ ) (i = 1 to 3), and the value Zi = M x Wi (i = 1 to 3) is sequentially stored in register 6.
Store it in 02. While the printed material passes through the detection field of view, the counter 603 reads out the values of Zi in order.
The counter 603 counts until it reaches Zi, outputs the instantaneous shift pulse SP that matches, the counter 603 automatically zeros the count value, and transfers the shift pulse SP to the register 602.
By resetting it, the next Zi is read out, and this
The counter 603 continues counting until it reaches Zi. By continuing this operation until the printed matter finishes passing through, the printed matter is divided into N ₁ , N ₂ , N ₃ as shown in Figure 5.
It is possible to obtain shift pulses SP that are divided into ratios of . In the example described above, the case of three divisions was described, but if the storage capacity of the register 602 is increased, it is also possible to implement the process for any number of divisions.

In the embodiments described so far, all division circuits have been used to perform the classification, but by controlling the output frequency of the oscillator 303 according to the value M calculated in advance by the counter 304, You can also get the same effect. In this case, the means for controlling the output frequency of the oscillator 303 is as follows:
Either analog control or digital control is fine.
In the case of analog control, V ₀ C as shown in Figure 6b
(Voltage controlled oscillator) 604 may be used to convert the count value M into an analog value using a D/D converter 605 or the like, and the converted value may be input to the V ₀ C 604 . In the case of digital control, PLL (phase lock loop) type oscillation frequency control can be considered.

〔Effect of the invention〕

According to the present invention, just before detecting information from the printed matter surface, the passing time of the printed matter with respect to the detection head is measured, and based on the measured value, the generation interval of the classification signal for classifying the detected information is determined. In other words, since a sorting signal is generated according to the current conveyance speed and printed matter condition, it is possible to always accurately determine whether the conveyance speed is changed or the size of the printed matter changes.The practical advantage of this is that It is enormous.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the entire printed matter discrimination device, FIG. 2 is a diagram showing a conventional sorting circuit, FIG. 3 is a diagram showing an embodiment of the sorting circuit used in the present invention, and FIGS. Figures 4b and 4c are diagrams for explaining one embodiment of the present invention, Figure 5 is a diagram showing the effects of another embodiment of the present invention, and Figures 6a and 6b are diagrams for explaining an embodiment of the present invention. FIG. 7 is a diagram showing another embodiment of the invention. 301, 302... AND circuit, 303... Oscillator, 304, 307... Counter, 305... Division circuit, 306... Register, 308... Shift register.

Claims (1)

[Claims] 1. Information such as the distribution of magnetic substances contained in the printed matter, the printed pattern, or the distribution of hue is sequentially stored in a register by moving the printed matter relative to a fixed detection head while conveying the printed matter at a constant speed. , a device for determining whether a printed matter is correct or not, or its type, etc. from this pattern information, includes a classification signal generation means for classifying information to the register for each divided area of the printed matter surface, and a classification signal generating means for classifying information to the register for each divided area on the printed matter surface, and a classification signal generating means for classifying information to the register, and a classification signal generation means for classifying information to the register for each divided area on the printed matter surface, and a classification signal generating means for classifying information to the register, and means for detecting a passing time determined in advance by the conveyance speed and length of the printed matter, and the sorting signal generating means determines the generation interval of the sorting signal based on the passing time obtained by the passing time detecting means. A printed matter discrimination device characterized by: 2. The classification signal generating means is equipped with a first photoelectric switch and counter, a second photoelectric switch and counter, a clock generator, a divider, and a register, and the first photoelectric switch is configured to detect signals from the detection point by the detection head on the transport path. A second photoelectric switch is installed in front of the longest dimension of the printed matter to be inspected, a second photoelectric switch is installed close to the detection head on the conveyance path, and a first counter is installed in front of the longest dimension of the printed matter to be inspected. The clock pulses from the clock generator are counted while the clock pulses are being obtained, the divider divides this count value M by the number of sections N, the register stores this division value m, and the second counter counts the clock pulses from the clock generator. 2. The counting of the clock pulses is started from the time when the signal reaches the photoelectric switch No. 2 and a signal is obtained, and the pulse output every time the content of the register is reached is used as the division signal. Printed matter identification device. 3 When dividing the surface of the printed matter to be tested into ratios of P ₁ :P ₂ :...:P _N (N is a natural number), the divider divides the count value M into Pi -- _N 〓Pi ⁱ⁼¹ (i=1~ N) to find the 1-segment value mi, and the register is set to this mi
(i=1 to N) are sequentially stored, and the second counter outputs a classification signal every time the count value of the clock pulse sequentially reaches mi (i=1 to N) in the register. The printed matter discrimination device according to scope 2.