JPH04348207A - Thickness measurement method - Google Patents

Abstract

PURPOSE:To obtain a thickness evaluating apparatus which can evaluate the approximate thickness of a sheet of paper or the like by using the transmission data of light and a thickness evaluating method using the apparatus, whereby the average value of the thickness of the sheet of paper or the like is obtained from the amount of the transmitting light thereby to detect the kind of the overlapped or thin paper. CONSTITUTION:This apparatus is provided with a sensor means 101 for measuring the data of the transmitting light, corresponding to each pixel of a sheet of paper or the like, an amplifying means 102 for amplifying the data of the transmitting light, an A/D converting means 103 for A/D converting the amplified data, a data processing means 104 for computing the average value of the digital values of all the images of the data obtained corresponding to each pixel, and comparison/evaluating means 105, 108 for comparing the processed data with the dictionary data.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] A device for processing paper sheets in the field of information processing, which is a thickness determination device that can roughly determine the thickness of paper sheets using light transmission data. This article relates to the thickness determination method used.

0002

[Prior Art] In a paper sheet processing device, the entire paper sheet to be inspected is divided into minute areas, and each minute area is inspected by a plurality of optical sensors, magnetic sensors, etc. arranged in an array to detect its pattern. After measuring the shading, amplifying the measured value to a desired value, and A/D (analog to digital) conversion, the value is subjected to various image processing and compared with pre-prepared dictionary data. Determining the authenticity of items.

Conventionally, in paper sheet processing apparatuses such as those described above, a method of determining the thickness of paper sheets has been used as one item for determining authenticity. This is a machine that uses a displacement sensor to read the force with which a roller placed on the conveying surface of paper sheets is pushed upward when the paper sheets are transported, and converts it into an electrical signal to detect the thickness of the paper sheets. This is a method that uses standard sensors.

0004

[Problem to be Solved by the Invention] Conventionally, however, such mechanical thickness sensors require precision because of the need to detect the thickness of paper sheets in micrometer units due to their structure, and are therefore expensive. There was a problem. Further, although such precision is not required, there is a problem that it is inappropriate as an inexpensive device that requires a certain degree of thickness determination.

[0005]Furthermore, due to the structure, there is a risk of misjudging the thickness if the roller bounces due to minute dust etc. attached to the paper sheet or if a part of the paper sheet is bent, so another method is used. It was necessary to determine the thickness value using this as a reference and perform the thickness determination. Therefore, an object of the present invention is to determine the average value of the thickness of paper sheets from the amount of transmitted light, so that the determination of overlapped paper sheets and paper sheets that have become thin media can be performed using a hardware device. The objective is to make it easily possible by adding .

[0006]

[Means for Solving the Problems] In one embodiment of the present invention, as shown in FIG. 1, a sensor means 101 for measuring light transmission data corresponding to each pixel of a paper sheet, an amplifying means 102 for amplifying the data; and an A/D converting means 103 for A/D converting the amplified light transmission data.
, a light transmission data processing means 104 that calculates an average value for all pixels of the digital values of light transmission data obtained corresponding to the pixel, and a comparison determination means 105 that compares the processed data with dictionary data. , 108 is provided.

In another embodiment of the present invention, a thickness determination device equipped with a sensor means for measuring light transmission data of the paper sheet is used to carry out the next processing step, that is, to determine the light transmission data of each pixel of the paper sheet. a processing step for obtaining data; a processing step for amplifying the light transmission data; a processing step for converting the amplified light transmission data from an analog value to a digital value; a processing step for adding the light transmission data of each pixel; A processing step of dividing the added value by the total number of pixels to obtain an average value of light transmission data, a processing step of applying the processing step to a typical paper sheet to obtain the average value and storing it as a dictionary, and determining the thickness. A processing step of comparing the average value of light transmission data obtained for the paper sheet to be measured with an average value of a dictionary, and a processing step of determining whether the thickness of the paper sheet to be measured is normal or abnormal based on the comparison. A thickness measuring method using a thickness determining device is provided.

[0008]

[Operation] By using the present invention, the data of the amount of light transmission corresponding to each pixel of the paper sheet determined by the sensor means 101 is obtained, and after being amplified and A/D converted, the data is processed by the light transmission data processing means. Average light transmission amount data per pixel can be obtained. By obtaining this data for a typical paper sheet, storing it as a dictionary, and comparing it with the measured average light transmission amount data, it is possible to determine whether the thickness of this paper sheet is normal or abnormal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows a block diagram of a thickness determining apparatus as an embodiment of the present invention. This device includes a paper sheet entry sensor section 100, a sensor section 101, an amplification section 102,
A/D conversion section 103 , light transmission data processing section 104 ,
A dictionary comparison unit 105 as a comparison/determination unit, a dictionary data unit 108 , a storage unit 106 , and a central processing unit 107
Equipped with.

The sheet entry sensor section 100 detects that a sheet has been conveyed, and the central processing unit 107 receives this detection signal and activates the sensor section 101. When a paper sheet passes, the sensor section 101 irradiates light from one side and receives transmitted light from the other side. And sensor part 1
01 samples data as necessary times in accordance with the conveyance of paper sheets under the control of the central processing unit 107. The sampling is performed for each pixel over the entire paper sheet.

[0011] The sampled data is sent to the amplifying section 102.
After being amplified by the A/D converter 103 and converted from an analog quantity to a digital quantity, a light transmission data processing part 104 adds only the internal data of the paper sheet and divides it by the number of added data. Light transmission data per pixel is determined. Next, the dictionary comparison unit 105 compares the dictionary data in the dictionary data unit 108 with the light transmission data per pixel, and the paper leaf authenticity determination result is stored in the storage unit 106.
is stored in As the dictionary data, for example, a lower threshold value and an upper threshold value as described later are used.

FIGS. 3 and 4 are divided flowcharts of the processing in the apparatus of the embodiment, and both diagrams are connected at point a to form one flowchart. At the start of the process, first, the content N of the register representing the number of pixels inside the paper sheet is initialized to 0, and the content S of the paper sheet internal data addition register is initialized to 0. Next, in step 1 (S1), light transmission data (
Measured value) Determine whether or not X is internal data of the paper sheet. If it is not internal data, proceed to step 4 (S4), and if it is internal data, set N+1 to N (S2), set S+X to S (S3), and proceed to step 4.

In step 4, it is determined whether or not all data processing has been completed. If not, the process returns to step 1, and if it has been completed, the process proceeds to step 5 (S5). In step 5, the calculation S÷N is performed to obtain T (light transmission data value per pixel), and the process proceeds to step 6 (S6), where it is determined whether T is larger than the lower limit threshold of the dictionary data. When T is larger than the lower limit threshold, the process proceeds to step 7 (S7), and when it is not greater, the process proceeds to step 9 (S9). In step 7, T
It is determined whether or not is smaller than the upper limit threshold of the dictionary data. If T is smaller than the upper threshold, step 8 (S8
), and if it is not smaller, proceed to step 11 (S11).

In step 8, the determination result by the optical sensor that the thickness is normal is stored in the storage section. In step 9, it is detected that two or more sheets overlap, and the storage section stores the fact that the determination result by the optical sensor is abnormal regarding the thickness (S10). In step 11, it is detected that the paper sheet is a thin medium, and in step 12, it is determined that the thickness is abnormal based on the determination result by the optical sensor, and the result is stored in the storage section. In this way, the process ends.

The above-mentioned thickness determination is obtained by noting that there is a certain relationship between the thickness of paper sheets and the amount of transmitted light, as shown in FIG. The lower threshold value and the upper threshold value are each calculated by statistically processing the distribution of sample results of a large amount of data of paper sheets that can be input.

The present invention can be achieved by adding some functions (addition and average value calculation) to the light transmission data processing unit in a conventional paper sheet authenticity determination device, and can be used to confirm thickness determination in the conventional device. It is useful for In addition, the amount of transmitted light used in the device of the example is the part of the paper sheet (watermark part,
Although there are slight differences depending on the area with dark patterns or areas with Braille, etc., the values for areas with paper sheets and areas without paper sheets are around 40-60 (relative value) for the former, and 150 (relative value) for the latter.
Since the relative value is greater than 80 (relative value), the threshold value can be set to about 80 (relative value).

[0017] In the present invention, the reason why the average value of the amount of transmitted light per pixel is used as the object of comparison is that it is possible to detect missing tickets where a part of the paper sheet is missing, complete double-sheeted tickets, etc. Conventionally, when a ticket is missing, an abnormality has been detected by determining the light intensity addition value, and the following processing has not been performed. Additionally, two stacked tickets are detected with a small amount of transmitted light, but this has the disadvantage that it is not possible to distinguish them from missing tickets.

[0018]

Effects of the Invention According to the present invention, by determining the average value of the thickness of paper sheets from the amount of transmitted light, the determination of overlapping paper sheets and paper sheets that have become thin media can be made using a hard disk drive. This can be easily done by adding some additional clothing. Although the thickness value determined by the present invention is an approximate value and is not as accurate as a mechanical sensor, the effect is significantly increased by using both together. Since optical sensors are always used in conventional devices, less additional hardware is required when the present invention is applied to conventional devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the principle of the present invention.

FIG. 2 is a block diagram of a thickness determination device according to an embodiment of the present invention.

3 is a partial flowchart showing the processing in the apparatus of FIG. 2 together with FIG. 4;

4 is a partial flowchart showing processing in the apparatus of FIG. 2 together with FIG. 3;

5 is a characteristic diagram showing the relationship between the light transmission output value and the thickness of paper sheets in the sensor unit used in the apparatus shown in FIG. 2; FIG.

[Explanation of symbols] 100...Paper sheet entry sensor section 101...Sensor part 102...Amplification section 103...A/D conversion section 104...Light transmission data processing section 105...Dictionary comparison section 106...Storage section 107...Central processing unit 108...Dictionary data section

Claims (2)

[Claims] 1. A sensor means (101) for measuring light transmission data corresponding to each pixel of a paper sheet, an amplification means (102) for amplifying the light transmission data, and an analog pair of the amplified light transmission data. A/D conversion means (103) for digital conversion; light transmission data processing means (104) for calculating the average value for all pixels of the digital values of light transmission data obtained corresponding to the pixel; and the processing Comparison/judgment means (105,
108) A thickness determination device for determining the thickness of paper sheets. 2. A next processing step, that is, a processing step of obtaining light transmission data for each pixel of the paper sheet using a thickness determination device equipped with a sensor means for measuring light transmission data of the paper sheet. a processing step of amplifying the light transmission data; a processing step of converting the amplified light transmission data from an analog value to a digital value; a processing step of adding the light transmission data of each pixel; and a processing step of adding up the light transmission data of each pixel; a processing step of calculating the average value of the light transmission data by dividing; a processing step of applying each of the above processing steps to a typical paper sheet to obtain the average value and storing it as a dictionary; and a processing step of calculating the average value of the paper sheet whose thickness is to be determined. A thickness determination device is used, comprising a processing step of comparing the average value of the light transmission data obtained with the average value of the dictionary, and a processing step of determining whether the thickness of the paper sheet to be measured is normal or abnormal based on the comparison. How to measure thickness.