ES2184646B1 - METHOD OF ANALYSIS OF THE VISUAL CLOUDY OF THE SECURITY ROLE, AND DEVICE FOR THE PRACTICE OF THE SAME. - Google Patents

Abstract

Method of analysis of the visual cloudiness of the security paper, and device for its implementation. The paper to be analyzed is passed through an acquisition unit (2), on a platform (5) thereof, from an entrance (6) to an exit (7), conveniently conducted by a guide (8) and pulled by a traction motor (10) with the collaboration of photocells (9-9 '') that detect the entry and exit of the paper, specifically by passing it through a transmitter-receiver assembly (12), in which the light beam is modulated by non-uniformity in paper thickness, variations in light modulation that are converted into voltage variations to be supplied to a processing and display unit in which a data acquisition card participates and a computer, where the signal becomes digital and where it is processed to extract the parameters that will characterize the cloudiness of the paper sample.

Description

Method of analysis of the visual cloudiness of the security paper, and device for the implementation of the same.

Object of the invention

The present invention relates to a new method of analysis of the visual aspect that presents the role of security, such as paper money, once manufactured and before being printed, looks very similar to that of a cloudy sky, for what internationally this visual feature is called `` cloudiness '', a denomination that will be used throughout the present description

The measure of this visual characteristic is of very important since the cloudiness of the substrate alters Several features of the final document.

The invention also concerns the process for the implementation of said method.

Background of the invention

Very varied solutions are known that measure or determine the translucency of a document to determine the cloudiness or visual appearance that presents a paper sample, or well to characterize them in some other way. In this sense there may be cited, among others, those set forth in US Pat. 4,630,845 for `` Document authentication system '' and EP 0268450 for `` Authentication method and system '', which describe document authentication systems based on translucency of a document. However, in these documents such translucency it is measured only in a certain area of a document so characterize and authenticate it, recording the information in a visible magnetic mark that incorporates the document itself and that is the one that stores the information that will then be compared with a certain pattern

Description of the invention

The method proposed by the invention allows analyze the visual aspect that the paper presents, that is the cloudiness, once manufactured and before being printed, for establish any type of assessment in this regard.

To do this and more specifically in this method The following operational phases are established:

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the paper is made pass between a light emitter and receiver, properly faced, the nominal frequency of these elements being corresponding to near infrared, that is to say with a length of wave between 870 and 980 nanometers.

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Non-uniformity of the paper generates a modulation in the incident light beam, and the variations in modulation are transformed into variations of voltage, which after being amplified and filtered are transferred to A data acquisition card.

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The captured signal by the data acquisition card is processed in a computer through software specifically developed to effect.

The device for the implementation of said method consists of an electro-mechanical unit acquisition, and a control computer that runs software developed exclusively for this purpose. The electromechanical unit of acquisition includes a housing where the paper is guided by a traction motor, photocells for position detection of the paper during its journey, and guides for a correct centering and displacement of it. Also, this electromechanical unit includes the corresponding adjustment systems, both of the traction motor speed, such as torque sensitivity sender-receiver

The adjustment unit is responsible for controlling the speed of said paper traction motor, as well as of adjust symmetry levels and torque sensitivity sender-receiver

The processing unit converts the signal analog voltage coming from the unit detector acquisition in a digital signal by means of the corresponding card of acquisition connected to the computer, in which the program cited computer will deduct the parameters that characterize Quantitatively the cloudiness.

Description of the drawings

To complement the description that is being performing and in order to help a better understanding of the characteristics of the invention, according to a preferred example of practical realization of it, is accompanied as an integral part of said description, a set of drawings where with character Illustrative and not limiting, the following has been represented:

Figure 1.- Shows a representation photographic of a banknote paper in which the cloudiness or visual aspect of the paper.

Figure 2.- Shows a block diagram corresponding to the cloudiness analysis device that It constitutes the object of the present invention.

Figure 3.- Shows, according to a representation in perspective, the set of elements corresponding to the diagram in the previous figure, except for the computer.

Figure 4.- Shows, according to a representation schematic in perspective, the acquisition unit that participates in the set of figures 2 and 3.

Preferred Embodiment of the Invention

In view of the figures outlined you can Observe how, to analyze the cloudiness of paper (1) represented in figure 1, an acquisition unit is used (2), a control and adjustment unit (3) and a unit of processing and visualization (4), the latter materialized in the combination of a data acquisition card and a computer.

The acquisition unit (2) materializes in a electromechanical element, in which a housing participates determinant of a higher platform (5) on which move the paper (1) to be analyzed, from an input (6) to a exit (7), platform on which a guide (8) is established for correct positioning and displacement of the paper.

An input photoelectric cell (9) detects the presence of paper on the acquisition unit (2), and puts in operating a drive motor (10), assisted by a potentiometer (11), while output photocells (9 ') interrupt the drive of said motor (10).

In the middle area of the platform (1) you establishes a transmitter-receiver set (12), as per example materialized in a light emitting diode (LED), having both the transmitter and the receiver a nominal frequency corresponding to near infrared, i.e. a wavelength between 870 and 980 nanometers, with the emission peak located at 930 nanometers.

The beam of light coming from the emitter crosses the paper and is picked up by the detector, so that as a consequence of non-uniformity in paper thickness, the beam light incident on the detector is modulated, determining The characteristics of cloudiness.

The said housing has a connector (14) to through which the acquisition unit (2) relates to the control and adjustment unit (3), which is responsible for controlling the motor speed (10) of paper traction, as well as adjusting symmetry levels and torque sensitivity transmitter-receiver, through a series of controls (fifteen). This unit also has an electronic filter, which provides the appropriate signal to the control computer (4) for subsequent treatment and representation.

As for the processing unit (4), this receives the analog voltage signal from the detector of the acquisition unit (2), converts it into a digital signal through the corresponding acquisition card and, once stored in memory, the computer performs the necessary processing to extract the parameters that will characterize the cloudiness of the paper sample (1). This stage of analysis is the fundamental part of the process, from which the parameters that characterize will be deduced Quantitatively the cloudiness. The parameters evaluated concern to the digitized signal, both in the spatial domain and in the transformed domain (frequencies). The analysis includes treatment signal statistic in both domains.

From the operational point of view the device requires a previous adjustment, specifically a motor adjustment (10) until a constant speed is achieved, through the potentiometer (11), and after achieving said motor adjustment, an adjustment is made opacity to its central value over the possible dynamic range. For achieve it adjusts the potentiometer of the symmetry control of the control unit (3), so that the output voltage level provided by the sensor falls in the center of the scale vertical.

After the average opacity adjustment, the sample of paper is passed through the device again, capturing the opacity signal throughout the entire paper, signal that is subsequently processed.

Claims (5)

1. Method of analysis of the visual cloudiness of the security paper, which with the purpose of extracting information on the uniformity of the paper in terms of opacity or cloudiness level, and being of the type of those that consist of passing the paper to analyze between a sender and receiver, generating the lack of paper uniformity a modulation in the incident light beam that is transformed into a voltage variation that is filtered, amplified and transferred to the data acquisition card where they are processed by means of a Specific software is characterized in that the nominal frequency at which the emitter and receiver elements work corresponds to the near infrared, that is, with a wavelength between 870 and 980 nanometers. 2. Device for the implementation of the method of the preceding claim, characterized in that it comprises an acquisition unit (2), a control and adjustment unit (3) and a processing and display unit (4) comprising the aforementioned acquisition card and a computer. 3. Device according to claim 2, characterized in that the acquisition unit (2), electromechanical in nature, incorporates a housing in which an upper platform (5) is established, for displacement of the paper (1) to be analyzed from an input ( 6) at an exit (7), platform (5) assisted by a paper positioning guide (8) and in which an emitter-receiver (12) is established, assisted by a fiber optic support (13), said unit also incorporating a traction motor (10) for the paper, controlled by an input photocell (9) and at least one output photocell (9 '), as well as with the control and adjustment unit (3), counting for this purpose with a connector (14) for connection of the acquisition (2) and control and adjustment units (3). Device according to claim 2, characterized in that the adjustment unit (3), responsible for controlling the speed of the paper traction motor (10), as well as adjusting the levels of symmetry and sensitivity of the transmitter-receiver assembly (12 ), incorporates an electronic filter that provides the appropriate signal to the computer of the processing unit (4), for further processing and representation. Device according to claim 2, characterized in that the processing unit (4) receives the analog voltage signal from the detector (12) of the acquisition unit and converts it into digital via the acquisition card, stores it in memory and The computer performs the necessary processing to extract the parameters that will characterize the cloudiness of the paper sample (1).