JP2007238324A - Method of detecting abnormal condition of folded paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of detecting the abnormal state of paper for enabling stable counting with high accuracy by detecting the abnormal states of a plurality of paper sheets during counting while preventing erroneous counting. <P>SOLUTION: The method comprises steps for aligning the plurality of folded paper sheets 1, irradiating them with light to generate brightness 5 and a shadow 6 on back portions 2 and recessed portions between the back portions, respectively, using a TV camera 7 for taking their images, converting the obtained image signals into multi-valued signals for the intensity of brightness, detecting the intensity of brightness in a range from one retainer plate through the plurality of paper sheets to the other retainer plate for one horizontal scanning line of the image signals, detecting a plurality of positions on the horizontal scanning line exceeding a reference value in the upward direction, calculating a plurality of lengths up to the position exceeding adjacent reference values in the upward direction, comparing them with the plurality of lengths up to the position exceeding the adjacent reference values previously detected and recorded by the same method for the plurality of paper sheets having no abnormality in the upward direction, and detecting the existence of the abnormalities of the plurality of folded paper sheets when the lengths are greater than a set length allowable rate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for detecting an abnormal state of a folded sheet, and more particularly to a method for detecting an abnormal state of a folded sheet of a printed material such as a catalog, a pamphlet, and a manual.

A large number of printed materials of the same type, such as catalogs, pamphlets, and manuals, are folded by a folding machine in order to arrange them into a predetermined size, and in that state, arrange them into a predetermined number of sheets. Therefore, it is necessary to count. As a method of counting such folded paper, as described in Patent Documents 1 and 2, etc., image information is obtained by imaging the back of the paper with a color TV camera or a monochrome TV camera, A method has been proposed in which luminance information is obtained using a luminance meter and the obtained video information and luminance information are binarized or binarized and counted.
Japanese Patent Laid-Open No. 61-272892 JP-A-3-238579

  However, even when multiple sheets of folded paper are imaged, a small number of sheets are misaligned and the back of the sheet is recessed, resulting in unexpected fraud. There is a risk of miscounting due to the alignment state of sheets, and sheets having different thicknesses due to a folding problem may be mixed in a plurality of sheets, or two sheets of folded sheets may overlap each other to have a thickness. There may be twice as many sheets of paper, which may not be suitable as a product, and the function of simply counting the number of sheets is not sufficient, requires visual inspection after counting, and requires a great deal of labor and cost. It was necessary.

  The present invention detects an erroneous count due to the occurrence of a small number of subtle irregularities that cannot be avoided during imaging of a plurality of folded sheets of the same type, and includes in a plurality of sheets. By detecting improper products at the time of counting, such as mixed sheets with different thicknesses of very few sheets and sheets with different thicknesses due to overlapping of folded sheets, It is intended to provide a method for detecting abnormal states of paper that can detect abnormal states at the time of counting and prevent erroneous counting and improper mixing of products to enable stable and accurate counting. Is.

  The present invention achieves the above-mentioned object, and the invention of claim 1 arranges a plurality of folded sheets, presses the aligned sheets from both sides with a pressing plate, and illuminates the back from an oblique direction. Illuminate the projections on the back and create shadows on the recesses between the backs. The backs of the aligned sheets and the pressing plates on both sides are front TV cameras, and the shadows are the TV cameras. The image signal obtained by (1) is imaged so as to be perpendicular to the horizontal scanning line of the image signal, and the obtained image signal is converted into a multivalued signal with respect to the intensity of brightness. Then, the intensity of the brightness up to the other pressing plate is detected for one horizontal scanning line of the image signal, and the intensity of the brightness signal for one horizontal scanning line is set to the set bright part and shadow part. Compared with the reference value that distinguishes between the start and end of the horizontal scanning line, the reference A plurality of positions on the horizontal scanning line that exceed the upper direction are detected, and then, on the horizontal scanning line, the length from the position of the starting end to the position where the reference value is exceeded upward for the first time, and the adjacent from the first time to the last A plurality of lengths up to a position exceeding the matching reference value in the upward direction and a length from the last position exceeding the reference value in the upward direction to the position of the end of scanning are respectively calculated, and the same for a plurality of sheets having no abnormality in advance. The length from the position of the start edge detected and recorded by the method of the first time to the position where the reference value was exceeded upwards for the first time, and a plurality of lengths from the first time to the end where the adjacent reference values were exceeded for the upward direction Finally, the length from the position exceeding the reference value in the upward direction to the position at the end of scanning is sequentially compared, and if the set length is larger than the allowable ratio, the presence of abnormalities in the folded sheets is confirmed. Features that detect The invention of claim 2 aligns a plurality of folded sheets, presses the aligned sheets with a pressing plate from both sides, and obliquely strikes the back part from the oblique direction. Irradiate light to create a bright part on the convex part of the back part and a shadow part on the concave part between the backs. The back part of the plurality of aligned sheets and the pressing plates on both sides are a TV camera from the front, and the shadow part is the TV The image signal obtained by the camera is imaged so as to be perpendicular to the horizontal scanning line of the image signal, and the obtained image signal is converted into a multivalued signal with respect to the intensity of brightness. Then, the intensity of the brightness up to the other pressing plate is detected for one horizontal scanning line of the image signal, and the intensity of the brightness signal for one horizontal scanning line is detected based on the set bright portion and shadow. Compared with the reference value for distinguishing the part, A plurality of positions on the horizontal scanning line that exceed the reference value in the upward direction, and then, on the horizontal scanning line, the length from the position of the start end to the position that exceeds the reference value in the upward direction for the first time, and from the first time A plurality of lengths up to the position exceeding the adjacent reference value up to the last and a length from the position exceeding the reference value up to the position of the end of scanning are calculated respectively, The length from the start edge position that was detected and recorded using the same method to the position that exceeded the reference value upward for the first time, and the length that exceeded the adjacent reference value from the first time to the end. When the average value of the length and the length from the position that finally exceeds the reference value upward to the position of the end of scanning are sequentially compared, and are larger than the set length allowable ratio, a plurality of folded sheets Detecting the presence of anomalies A method of detecting an abnormal state of the folded processed sheet is characterized.

  According to the method for detecting an abnormal state of a folded sheet according to the present invention, an erroneous count due to the occurrence of a small number of subtle irregular states that cannot be avoided when imaging a plurality of folded sheets of the same type. Can be detected at the time of counting, and a few sheets with different thicknesses mixed in a plurality of sheets or sheets with different thicknesses due to overlapping of folded sheets are not used. Appropriate products can be detected at the time of counting. By detecting the abnormal state of the plurality of sheets at the time of counting, it is possible to perform stable and highly accurate counting in which erroneous counting of sheets is prevented and improper mixing of products is prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an example of a sheet folded to a desired size. 1 is a folded sheet, 2 is a back part of the folded sheet 1, and the back part 2 is a semicircle as shown in the figure. Become a shape. As the folded sheet 1, various kinds of sheets having different colors, folded shapes, and thicknesses can be used. However, in the same counting, the same kind of sheet 1 is used and the same kind of color, folded shape. It is desirable to use a thick one. Among them, there are a few abnormal states such as an alignment state, thickness, and overlap, and the present invention detects such abnormal states.

  FIG. 2 shows a means for detecting an abnormal state of a plurality of folded sheets 1, and aligns the folded sheets 1 so that the back portions 2 are aligned on the same plane, and press plates from both sides. 3, and the illumination device 4 irradiates light from an oblique direction in front of the back part 2 to generate a bright part 5 at the convex part of the back part and a shadow part 6 at the concave part between the backs. The illuminating device 4 may be arranged on either the right side or the left side, but if it is arranged in both the right and left diagonal directions and irradiated from both diagonal directions, uniform illumination is possible. is there. It is desirable that the angle of illumination and the distance between the lighting device 4 and the paper 1 are appropriately adjusted so that a shadow is easily generated between the backs depending on the folding shape of the paper 1 and the thickness of the paper. Horizontal scanning of the shadow portion 6 and the TV camera signal is performed so that all the shadow portions 6 are imaged by the television camera 7 in which the back portion 2 and the holding plates 3 on both sides of the aligned sheets 1 are fixedly arranged in front of the same. Take an image so that it is perpendicular to the line. The position of the television camera 7 is preferably the center of the plurality of sheets 1 so that left and right can be imaged uniformly. The obtained image is checked on the image monitor 8 to obtain a good image.

  Next, when the TV camera 7 is a color TV camera, the image signal obtained from the color TV camera is separated into the three primary colors of red, green and blue by the three primary color separation circuit 9 and sent to the computer 10 for separation into the three primary colors. The intensity of each color of the converted signal is converted into a multivalued color signal for each point constituting the horizontal scanning line. All of the obtained signals of the three primary colors can be used for counting, or the optimum color signal that appears most strongly according to the color of the paper can be selected and used as a representative signal. In particular, when the paper color is amber / blue, only the blue signal appears clearly and the intensity of the red / green color becomes unclear, so it is better not to use it for counting to prevent miscounting. Often good. In the case of dark blue / blue paper colors, it is difficult to count using a monochrome camera. Therefore, it is desirable to use a color television camera for counting papers of these colors.

  When the television camera 7 is a monochrome television camera, the obtained image signal is not sent to the three primary color separation circuit 9 but directly to the computer 10 in FIG. 2, and the brightness of the image signal is set to each point constituting the horizontal scanning line. Is converted to a multi-valued signal.

  In counting the plurality of sheets 1 aligned, the intensity of the signal at each point constituting the horizontal scanning line from one pressing plate 3 through the plurality of sheets 1 to the other pressing plate 3 is expressed as a shadow. Detects one horizontal scanning line in a direction perpendicular to the unit 6, and displays the horizontal scanning line composing point on the X axis and the signal strength on the Y axis on the computer monitor 11 as shown in FIG. Then, a graph connecting the points indicating the signal strength for each point of the horizontal scanning line composing points with a straight line is displayed. In this graph, the bright part 5 and the shadow part 6 form peaks and valleys and appear to swing, and the bright part 5 and the shadow part 6 can be known as the difference in signal strength.

  Using the appearance of this signal, the color intensity of one horizontal scanning line is analyzed from one holding plate 3 through the plurality of sheets 1 to the other holding plate 3. However, as shown in FIG. 3, it can be seen that there is a problem in accurate counting and calculation due to the fact that subtle noise occurs in the middle of the peak and valley as shown in FIG.

  As shown in the graph of FIG. 3, when noise is included in the signal due to the shape of the back portion, the characteristics of the paper, and the printing state, a moving average is performed using the following formula in order to remove the noise, and the graph shown in FIG. It is desirable to remove noise as shown in FIG. FIG. 3 shows the state of the graph before the actual moving average, and FIG. 4 shows that the number of sheets is 24, the number of horizontal scanning line constituting points is 640, the average number is 12, and the actual moving average after moving average is obtained. A graph is shown.

An example in which noise is removed using a moving average method using mathematical expressions will be described below.
FIG. 5 is a schematic graph in which the strength of the obtained signal is displayed from the start edge of the horizontal scanning line to three sheets of paper. The horizontal scanning line is shown on the X axis, the signal strength is shown on the Y axis, and the horizontal The signal strengths S0, S1, S2, S3,... S48, S49, S50, and S51 from the scanning line start end are plotted on a graph and connected between the points, and S6, S25, S30, and S45. It can be seen that noise is included. These points stand out from the average tendency before and after.

  Therefore, in order to remove these noises, the signal strength Sx of each point from the horizontal scanning line start end to the end end is averaged, and the signal strength of each point and a plurality of points around it are averaged. By correcting to the average value, the protrusion from the average tendency before and after is removed. Therefore, the average value of the arbitrary point Sx is a value obtained by averaging the signal strengths of the point Sx and a plurality of points around it. Here, assuming that the number before and after (average number) used for averaging is n before and after, the total number (average number) used for averaging is n + n + 1.

Thus, to explain with an example where n = 3, the average value of the point S3 is
Average value of S3 = (S0 + S1 + S2 + S3 + S4 + S5 + S6) ÷ (3 + 3 + 1).
Therefore, the average value of an arbitrary point Sx when n = 3 is calculated as follows.
Average value of Sx = (S (x−3) + S (x−2) + S (x−1) + Sx + S (x + 1) + S (x + 2) + S (x + 3)) ÷ (3 + 3 + 1)
Therefore, in general, the average value of an arbitrary point Sx when n = n is calculated as follows.
Average value of Sx = (S (x−n) +... + S (x−1) +... + Sx +... + S (x + 1) +... + S (x + n)) ÷ (n + n + 1)

However, as in the case of S0, when there is no data on the front side of the point, or when n = 5 and the required number of data does not exist on the front side, as in the case of S4, the horizontal scanning line ends similarly. If necessary data does not exist on the back side near the edge, averaging is performed only with existing data.
That is, when n = 5 and S4, the calculation is performed according to the following formula.
Average value of S4 = (S0 + S1 + S2 + S3 + S4 + S5 + S6 + S7 + S8 + S9) ÷ (4 + 5 + 1)
It should be noted that an appropriate value of n is preferably selected depending on the state of the sheet to be counted, but is preferably about 40% to 60% of the value obtained by dividing the number of points constituting the horizontal scanning line by the scheduled number of sheets. .

FIG. 6 is a graph when noise is removed by moving average using the above calculation formula, and the thicknesses of a plurality of sheets 1 can be counted using this graph.
When actually counting the number of sheets 1 and the thickness, etc., the same type of sheets 1 with no ideal abnormality are properly aligned between the holding plates in advance and imaged, and the obtained image information is appropriate. To create a graph in which the bright and shadow areas clearly appear, and to detect the number of points where the reference line and graph that can clearly distinguish the bright and shadow areas intersect when the transition from the shadow area to the bright area , And the thickness of the ideal paper 1 is measured and recorded, and then the actual same type of paper 1 divided so as to have almost the same number as necessary is the same press plate as above. Acquire the image status by interval, imaging status, and averaged number, create a graph, count the actual number of sheets, calculate the thickness of the paper, and compare the recorded thickness with the actual paper thickness Thus, an abnormal state such as the actual thickness of the plurality of sheets 1 can be detected. Hereinafter, this principle will be described in detail.

  FIG. 7A shows a state in which 12 sheets of the same type of folded and ideally uniform sheet are arranged between the pressing plates 3. FIG. 7B shows an image of the signal at each point constituting the horizontal scanning line by taking an image from one presser plate 3 of FIG. 7A to the other presser plate 3 through a plurality of folded sheets 1. This is a graph in which one horizontal scanning line is detected and moving averaged with an appropriate number of averages, and appears in a shape in which the signal intensity of the bright part and the shadow part alternately amplitude. Here, as shown in the figure, a reference line that clearly separates the bright part from the shadow part is set, and the graph exceeds the reference line from the bottom to the upper end from the horizontal scanning line start end to the end end, and is determined to be a bright part A plurality of positions a, b, c, etc. on the horizontal scanning line entering the area that can be detected are detected. Next, the length from the horizontal scanning line start end to the position that first exceeds the reference line in the upward direction is calculated, and this is shown as the start end length (length from the start end) A in the figure. Further, a plurality of lengths between adjacent positions that exceed the reference line in the upward direction are calculated, and these are shown as sheet thickness lengths B, C, D,... The length from the position exceeding the reference line to the end of the horizontal scanning line is calculated, and this is shown as end end length (length to end end) M in the figure. Each length from A to M is calculated and recorded sequentially, and the total length between adjacent positions from B to L is calculated and recorded, and the number of times the graph crosses the reference line in the upward direction is integrated, The number of sheets is recorded, and the average length between adjacent positions from B to L is calculated and recorded.

  Note that even if the subject that is originally imaged uniformly is the same type of paper at the center and at the edge, depending on the lens performance of the camera to be imaged, the imaging angle, etc., the thickness of the paper as in B to L in this example In many cases, the length corresponding to the length is different. The respective lengths recorded here are used as comparative recorded values when inspecting abnormal states such as thickness and unevenness of a plurality of sheets of the same shape used for actual counting using the same device.

  FIG. 8A shows a state in which 12 sheets of actual inspection paper that have been folded are arranged between the pressing plates 3. In this figure, the case where there is a sheet having a different thickness due to a defect in the folding process on the fourth sheet from the left is shown. FIG. 8B shows the intensity of the signal at each point constituting a horizontal scanning line by taking an image from one presser plate 3 of FIG. 8A to the other presser plate 3 through a plurality of folded sheets 1. This is a graph in which one horizontal scanning line is detected and moving averaged with an appropriate number of averages, and appears in a shape in which the signal intensity of the bright part and the shadow part alternately amplitude. Here, as shown in the figure, a reference line that clearly separates the bright part from the shadow part is set, and the graph exceeds the reference line from the bottom to the upper end from the horizontal scanning line start end to the end end, and is determined to be a bright part A plurality of positions a, b, c, etc. on the horizontal scanning line entering the area that can be detected are detected. Next, the length from the horizontal scanning line start end to the position exceeding the reference line in the upward direction first is calculated. This length is shown as a start end length (length from the start end) A in the drawing. Furthermore, a plurality of lengths between adjacent positions exceeding the reference line in the upward direction are calculated. These are shown as sheet thickness lengths B, C, D ·· L, etc. in the figure. Finally, the length from the position exceeding the reference line in the upward direction to the end of the horizontal scanning line is calculated. This length is shown as the end length (length to the end) M in the figure. Each length from A to M is sequentially calculated and recorded.

The calculated start end length, sheet thickness length, and end end length are compared with the corresponding comparative recording values. In the figure, the calculated lengths are 7 (B) corresponding to the calculated lengths. The calculated and recorded length is shown in parentheses.
When the allowable value is 10% and the calculated value is compared with the corresponding comparative recording value, the calculated value of the thickness of the fourth sheet from the left is 16, and the comparative recording value is 14, so (16 −14) ÷ 14 × 100 = 14.3%, which is found to be thicker than the permissible range, indicating that there is a sheet with an abnormal thickness, or that there is a lifting abnormality due to unevenness. If there is an abnormality in the paper thickness, the ratio of the difference between the calculated value and the recorded value for comparison is often less than 30%, and this is the case in this example. It can be clearly determined that it exists.

  As described above, when the number of actual inspection sheets is the same as the number of sheets of comparative recording values, the calculated lengths are compared with the corresponding lengths, and the calculated numerical values are set. If the value is larger than the value, it is possible to detect the presence of abnormally thick paper or the presence of irregularities due to unevenness, but the actual number of sheets at the time of inspection differs from the number of recorded values for comparison. However, if the same number is detected because the sheets are uneven, it is possible to detect the abnormal state of the sheet in the same manner. This will be described in detail below.

  FIG. 9A shows a state in which 13 sheets of actual inspection paper that have been folded are arranged between the pressing plates 3. This figure shows a state in which the first sheet from the left is not aligned and the sheet is lifted and the count value is 12. FIG. 9B shows an image with the same configuration as FIG. 7B, and the signal of each point has the same value as FIG. 7B from the bottom to the top in the horizontal scanning line start end to the end end. Detects the position of the horizontal scanning line that exceeds the reference line and enters the area that can be determined as a bright part, calculates the start edge length, paper thickness length, and end edge length, and compares them with the corresponding comparative recording values To do. In the figure, each calculated length and the corresponding length calculated and recorded in FIG. 7B are shown in parentheses.

  When the allowable value is 10% and the calculated recording value is compared with the corresponding comparative recording value, the calculated value of the thickness (starting end length) of the first sheet from the left is 21, and the comparative recording value is 9. Therefore, (21−9) ÷ 9 × 100 = 133.3%, which is found to be thick beyond the allowable range, indicating the presence of abnormally thick paper or the presence of abnormal lifting due to unevenness. The abnormal condition of the paper lift is often 50% or more of the difference between the calculated value and the recorded value for comparison, and this is the case in this example. Can be determined.

  As described above, when the actual number of inspection sheets is the same as or the same as the number of sheets of comparative recording values, the calculated lengths are compared with the corresponding lengths. If the measured value is larger than the set tolerance, it is possible to detect the presence of abnormal paper width or the presence of abnormal lifting due to irregularities, but the actual number of paper at the time of inspection is for comparison. For example, when the number of recorded values is larger than the recorded value, the number of times of exceeding the reference line in the upward direction is different, so the number of adjacent position lengths is increased by the larger number, Since there is no length at the adjacent position corresponding to the comparison recording value, comparison cannot be made, and this case will be described in detail below.

  FIG. 10A shows a state in which 13 sheets of actual inspection paper that have been folded are placed between the pressing plates 3. The state from which the sheet | seat from which thickness differs by the malfunction of a folding process exists in the 6th sheet from the left is shown. FIG. 10B is an image with the same configuration as FIG. 7B, and the signal of each point has the same value as FIG. 7B from the bottom to the top in the horizontal scanning line start end to the end end. Detects the position of the horizontal scanning line that exceeds the reference line and enters the area that can be determined as the bright portion, calculates the start edge length, the sheet thickness length, and the end edge length, and compares them with the corresponding comparative recording values. . Each calculated length and the corresponding length calculated and recorded in FIG. 7B are shown in parentheses. In the case of this example, the number of calculated values is 13, which is 12 comparison recording values, which are different and there are few comparison recording values. Use the averaged value.

  When the allowable value is 10% and the comparison recording value (average value) corresponding to the calculation value is compared, the calculation value of the thickness of the sixth sheet from the left is 16, and the comparison recording value (average value) is 14 (16−14) ÷ 14 × 100 = 14.3%, it is found that the thickness exceeds the allowable range, and it is possible to detect the presence of abnormally thick paper or the presence of abnormal lifting due to unevenness. . If there is an abnormality in the paper thickness, the ratio of the difference between the calculated value and the recorded value for comparison is often less than 30%, and this is the case in this example. It can be clearly determined that it exists.

  As described above, in addition to the case where the actual number of test sheets is different from the number of sheets for comparative recording values, the actual number of test sheets is the same as the number of sheets for comparative recording values. However, even when there is an abnormal lifting state due to unevenness, the actual number of sheets for inspection differs from the number of sheets for comparison recording values. Hereinafter, this case will be described in detail.

  FIG. 11A shows a state in which 12 sheets of actual inspection paper that have been folded are placed between the pressing plates 3. This shows a state in which the second sheet from the left is not aligned and the sheet is lifted and the count value is 11 sheets. FIG. 11 (B) images with the same configuration as FIG. 7 (B), and the signal of each point has the same value as FIG. 7 (B) from the lower end to the upper end in the horizontal scanning line start end to end end. Detects the position of the horizontal scanning line that exceeds the reference line and enters the area that can be determined as the bright portion, calculates the start edge length, the sheet thickness length, and the end edge length, and compares them with the corresponding comparative recording values. . The calculated lengths and the corresponding lengths calculated and recorded in FIG. 7B are shown in parentheses. In this example, the number of calculated values is 11, and the comparison record is recorded. Since there are 12 different values and there are many comparative recorded values, the recorded average value is used as the corresponding comparative recorded value.

  When the allowable value is 10% and the comparison recording value (average value) corresponding to the calculation value is compared, the calculation value of the thickness of the first sheet from the left is 26, and the comparison recording value is 14. (26−14) ÷ 14 × 100 = 85.7%, and it is found that the thickness exceeds the allowable range, and it is possible to detect an abnormal lifting due to the presence or unevenness of the sheet having an abnormal thickness. If there is an abnormal paper lift, the difference between the calculated value and the recorded value for comparison is often 50% or more. This is the case in this example, but there is an abnormal condition in any case. Then it can be clearly determined.

  FIG. 12 shows an example of a display screen of the computer monitor during the counting inspection, in which the calculated number is displayed numerically and the constituent points from the horizontal scanning line start end to the end end are displayed in the graphic paper information display area. If an abnormal sheet is detected, an approximate position is displayed in a graphic form within the area based on the detected position information to indicate the occurrence and location of the abnormality. In the case of this example, it indicates that an abnormality is detected around the second sheet from the right end.

  As described above, when the number of actual inspection sheets is the same as the number of sheets of comparative recording values, the calculated lengths are compared with the corresponding lengths, and the calculated numerical values are set. If the value is larger than this value, the presence of abnormally thick paper or the presence of irregularities due to unevenness is detected, and the number of sheets calculated simultaneously at the time of inspection differs from the stored number of sheets. If there are many, the number of times of exceeding the reference line in the upward direction is different, so the number of length information of adjacent positions increases as the number increases, and the length of the stored adjacent positions to be compared does not exist. When a large number of sheets are arranged between the press plates installed at the same interval, the sheets are compressed as a whole, resulting in a change in the position and shape of the sheets, and the lengths of the stored adjacent positions are compared. Vs. Therefore, the start end length and end end length are compared with the stored start end length and end end length, respectively, and the length of adjacent positions is the average of the stored lengths of adjacent positions. If the calculated value is larger than the set allowable value, the presence of abnormal paper or the presence of abnormal lifting due to unevenness is detected, and the paper When the number of sheets is different from the stored number, and the number of sheets is smaller than the recorded value for comparison, the sheet spacing is increased by arranging the sheets with the smaller number of sheets at the same interval, resulting in a change in the position and shape of the sheet. The length of the adjacent position is compared with the stored start end length and the end end length, respectively, since the length of the stored adjacent position is less reliable for comparison. Remembered If the calculated value is larger than the set allowable value compared to the average value of the lengths of adjacent positions, the presence of abnormally thick paper or the presence of abnormal lifting due to unevenness is detected. .

In this example, the calculation and comparison are performed with reference to the start edge of the horizontal scanning line, but almost the same result is obtained when calculation and comparison is performed with reference to the end edge. Since the calculated thickness may differ depending on the delicate shape, the accuracy can be further improved by performing the calculation and comparison from two directions from the start end and the end end.
When the number of sheets is different from the comparison stored value, the error increases, so it is desirable that the allowable value used for the comparison is larger than that for the same number of sheets. In addition, when the number of sheets is different, it is difficult to detect a subtle abnormality in thickness, so that it is often used mainly for unevenness of sheets.

  It is a top view which shows an example of the folded paper.   It is explanatory drawing which shows the means to count the number of sheets of the several folded paper 1. FIG.   This is a graph showing horizontal scanning line composing points on the X-axis and signal strength on the Y-axis, showing a state in which noise before moving average is included.   This is a graph showing horizontal scanning line composing points on the X-axis and signal strength on the Y-axis, and shows a state in which noise after moving average is removed.   It is a schematic graph up to three sheets of paper, and shows a state in which noise before moving average is included.   It is a schematic graph up to three sheets of paper, and shows a state in which noise after moving average is removed.   (A) is a plan view showing an example of a plurality of folded sheets 1, and (B) is from the start end to the end of one horizontal scanning line obtained by imaging the sheet (A). It is the graph which displayed the strength of the signal so as to correspond to the position of (A).   (A) is a plan view showing another example of a plurality of folded sheets 1, and (B) ends from the start end of one horizontal scanning line obtained by imaging the sheet of (A). It is the graph which displayed the strength of the signal to correspond to the position of (A) to the end.   (A) is a plan view showing another example of a plurality of folded sheets 1, and (B) ends from the start end of one horizontal scanning line obtained by imaging the sheet of (A). It is the graph which displayed the strength of the signal to correspond to the position of (A) to the end.   (A) is a plan view showing another example of a plurality of folded sheets 1, and (B) ends from the start end of one horizontal scanning line obtained by imaging the sheet of (A). It is the graph which displayed the strength of the signal to correspond to the position of (A) to the end.   (A) is a plan view showing another example of a plurality of folded sheets 1, and (B) ends from the start end of one horizontal scanning line obtained by imaging the sheet of (A). It is the graph which displayed the strength of the signal to correspond to the position of (A) to the end.   It shows an example of a display screen of a computer monitor during counting inspection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Folded paper 2 Back part 3 Holding plate 4 Illumination device 5 Bright part 6 Shadow part 7 Television camera 8 Image monitor 9 Three primary color separation circuit 10 Computer 11 Computer monitor

Claims (2)

  Align multiple folded sheets, press the aligned sheets from both sides with a pressure plate, irradiate the back with light from an oblique direction, and add a bright part to the convex part of the back and a shadow part to the concave part between the backs The back and the holding plates on both sides of the plurality of aligned sheets were imaged with a television camera from the front so that the shadow portion was perpendicular to the horizontal scanning line of the image signal obtained by the television camera. The image signal is converted into a multi-valued signal with respect to the intensity of the brightness, and the intensity of brightness from one pressing plate through a plurality of sheets to the other pressing plate is determined by one horizontal scanning line of the image signal. The intensity of the signal of the brightness of one horizontal scanning line is compared with the set reference value for distinguishing the bright part from the shadow part, and from the start end to the end end of the horizontal scanning line , Detecting a plurality of positions on the horizontal scanning line exceeding the reference value upward, and then On the horizontal scanning line, the length from the position of the start end to the position where the reference value is first exceeded upward, the plurality of lengths from the first time to the end where the adjacent reference value is exceeded upward, and finally Calculate the length from the position that exceeds the reference value upward to the position of the end of scanning, and detect the reference value for the first time from the position of the start edge that was detected and recorded in advance for a plurality of sheets with no abnormality in advance. The length to the position exceeding the upper direction, the multiple lengths from the first to the last adjacent reference value to the position exceeding the upper direction, and the position from the last exceeding the reference value to the position of the end of scanning A method for detecting an abnormal state of a folded sheet, wherein the presence of an abnormality in a plurality of folded sheets is detected when the length is sequentially compared with a set length and is larger than an allowable ratio of the set length. .   Align multiple folded sheets, press the aligned sheets from both sides with a pressure plate, irradiate the back with light from an oblique direction, and add a bright part to the convex part of the back and a shadow part to the concave part between the backs The back and the holding plates on both sides of the plurality of aligned sheets were imaged with a television camera from the front so that the shadow portion was perpendicular to the horizontal scanning line of the image signal obtained by the television camera. The image signal is converted into a multi-valued signal with respect to the intensity of the brightness, and the intensity of brightness from one pressing plate through a plurality of sheets to the other pressing plate is determined by one horizontal scanning line of the image signal. The intensity of the signal of the brightness of one horizontal scanning line is compared with the set reference value for distinguishing the bright part from the shadow part, and from the start end to the end end of the horizontal scanning line , Detecting a plurality of positions on the horizontal scanning line exceeding the reference value upward, and then On the horizontal scanning line, the length from the position of the start end to the position where the reference value is first exceeded upward, the plurality of lengths from the first time to the end where the adjacent reference value is exceeded upward, and finally Calculate the length from the position that exceeds the reference value upward to the position of the end of scanning, and detect the reference value for the first time from the position of the start edge that was detected and recorded in advance for a plurality of sheets with no abnormality in advance. The average value of the length to the position exceeding the upper direction, the length of the position exceeding the adjacent reference value from the first time to the last, and the position of the scanning end from the position that finally exceeds the reference value upward In order to detect the abnormal state of the folded paper, it detects the presence of abnormalities in multiple folded papers when it is compared with the length of the paper in order Method.

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