JP2003213585A - Apparatus for monitoring paper quality, paper machine and method for making paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for monitoring paper quality, with which paper quality can properly be evaluated without being affected by influence of disturbance. <P>SOLUTION: A video camera 1 and a light emitting device 2 are opposingly arranged with a traveling line of wet paper 10 traveling in contact with at least one wire 20 between and the wet paper 10 is taken as a static two-dimensional image by the video camera 1. The image taken by the video camera 1 is processed by an image processor 6b and at least one, preferably both of a low-frequency noise component of density fluctuation and a periodic high-frequency noise component of density fluctuation are removed. Then, the quality of the wet paper is analyzed by the image processed by the image processor 6b and the analyzed result is indicated on a display 6c in time series. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quality monitoring device capable of evaluating the quality of paper manufactured by a paper machine in real time, a paper machine using the same, and a paper manufacturing method.

[0002]

2. Description of the Related Art FIG. 17 is a block diagram showing a schematic configuration of a general paper machine. The paper raw material liquid ejected from the head box 101 is dehydrated by one or a plurality of dehydrating devices on the wires of the former section 102 or between a pair of wires to form wet paper. The wet paper web formed by the former portion 102 is further squeezed by the press portion 103, and then the dryer portion 104.
Heat-dried to form paper. After that, the caliper (paper thickness) and the smoothness of the paper surface are adjusted by the calendar unit 105, and then the paper reel unit 106 winds the paper.

Texture is one of the items for quality inspection of paper manufactured through these steps. The texture means the degree of mass unevenness in the paper surface due to the dispersion and entanglement of pulp fibers, and has been conventionally judged by visual evaluation through the paper through transmitted light. The texture is even and uniform, and the texture can be adjusted mainly by adjusting the dehydrator of the former section. In recent years, in order to more objectively evaluate the formation, various types of formations have been put into practical use, which can quantify the formation by appropriately cutting, sampling, and measuring the paper after winding the reel. However, in such off-line measurement, it takes time to feed back the result of formation evaluation to the operation, so a formation evaluation method that can evaluate in real time has been proposed.

As one of such formation evaluation methods, there is a technique disclosed in Japanese Utility Model Publication No. 1-98199. In this technique, a detection device including a laser light source and a light receiver is arranged in a wire portion (former portion) of a paper machine so that the laser light passes through the wet paper web and the wire. Each frequency of the transmitted light detected by this detector shows the signal waveform of the overlay of the wet paper web and the wire, and the transmitted light is subjected to frequency analysis to form the overlay of the wet paper web and the wire. An index is created, and this formation index is converted into a formation index of paper using a constant according to the type of wire and the type of paper.

However, this technique is mainly based on the fluctuation of transmitted light in the running direction of the wet paper in the formation evaluation,
Information as a surface is missing. Also, the correspondence between the received light intensity at each frequency and the formation index changes depending on the raw material properties,
There is also a problem that the operator cannot grasp the feeling during papermaking. This is because, for example, the formation changes in various forms from granular to cloud-like due to the difference in fiber length, but when it is decomposed into frequency components as described above, the relation between the formation index and the unevenness of the formation index becomes rather unclear. It is due to becoming. Therefore, in order to intuitively make a one-to-one correspondence between the visual evaluation and the formation index for the mass variation of paper or wet paper, it is rather to quantify the grayscale variation of the two-dimensional image as in the technique described below. good.

As a technique of using a two-dimensional image for texture evaluation, there is a technique of Japanese Patent No. 2084674. With this technology,
The running paper is captured as a two-dimensional image by the video camera, A / D converted, and stored in the memory. The information in the memory is input to the first to third image signal processing devices in response to a calling instruction from the first image signal processing device. The first image signal processing device performs formation analysis by frequency analysis and standard deviation processing. The second image signal processing device also performs paper defect analysis. The third image signal processing device performs streak analysis on paper. Based on the output signals of the first to third image signal processing devices and the jet speed, wire speed and raw material concentration signals of the paper machine, the jet speed, wire speed and raw material concentration are The correlation analysis is performed by the arithmetic device, and the results of the correlation analysis are displayed on the display device. Thus, patent 20
The technology of No. 84674 makes it possible to easily understand the relationship between jet speed, wire speed, and raw material concentration, which are factors that affect the formation and streak of running paper, and prevent formation deterioration and streak during papermaking operation. It is structured so that countermeasures can be taken easily.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The technique of No. 084674 does not take into consideration variations in light and shade in the image due to disturbances such as irradiation unevenness of the light emitting device, wire patterns of wires or random high frequency noise. Therefore, when the influence of these disturbances is large, there is a problem that the formation cannot be properly digitized and feedback cannot be properly fed back to the operation. In particular, when the stroboscopic light emitting device is used as the light emitting device, the stroboscopic light emitting device is a point light source, and the emission intensity has a characteristic of decreasing in the concentric direction with the emission center being the maximum, so that the unevenness of light and shade has a great influence. It is considered to be a thing.

In recent years, a system in which a paper defect detection device is provided with a texture evaluation function has appeared. Basically, these are so-called "papers" that have been subjected to texture evaluation after drying in a dryer section. I have to. Paper that has become defective due to formation evaluation is reused as a raw material, but paper that has undergone a drying process cannot be used as a good quality raw material because the physical properties of paper such as formation deteriorate due to deterioration of pulp properties. . In other words, in the conventional existing system, if the paper that has become defective due to the texture evaluation is reused, the quality such as texture may be further deteriorated.
Therefore, there has been a demand for an improvement method that minimizes the reuse of the raw material as it is.

Further, in a multi-layer paper machine equipped with a plurality of head boxes for making high basis weight paper such as paperboard, only the surface layer is made of an expensive raw material with excellent paper quality, and In many cases, inferior quality raw materials are used for the layer, so that the texture or surface feeling of the surface layer is particularly important. However, since the conventional system can only evaluate as at least one sheet of paper, if there is a problem in quality such as formation of the surface layer, is there a problem with the formation in the dehydration unit that forms the surface layer, or It was unclear whether there was a problem in combining the surface layer and the layer below it, and it took time to solve the problem.

The above problems are not limited to the formation. That is, it is a problem common to all quality monitoring devices that evaluate the quality of paper. For example, one of the paper qualities is the presence or absence of defects (abnormalities that impair the homogeneity of the product such as dust spots, foreign substances, scratches, and folds). Image analysis using a camera is used to detect this defect.Even if the former is attempted to detect this defect, the influence of disturbance such as irradiation unevenness of the light emitting device, wire pattern of wires, or random high-frequency noise will occur. If it is large, the defect cannot be detected accurately. On the other hand, when defect detection is performed on the so-called "paper" that has been dried in the dryer unit, even if the defective paper is reused as a raw material, it cannot be a good quality raw material.

The present invention was devised in view of the above problems, and an object thereof is to provide a paper quality monitoring device which enables proper paper quality evaluation without being affected by the influence of disturbance. To do. In particular, we provided a paper quality monitoring device that made it possible to quantify the proper formation, and by using this quality monitoring device, we made it possible to easily manufacture optimally adjusted paper. And a paper manufacturing method, and further, to provide a paper machine capable of effectively reusing damaged paper that has become defective due to formation evaluation, and an efficient paper manufacturing method using the paper machine. And

In addition, a paper quality monitoring device that enables accurate detection of defects is provided, and by using this quality monitoring device, a paper machine and a paper machine that can easily manufacture defect-free paper are provided. It is an object of the present invention to provide a manufacturing method, and further, to provide a paper machine capable of effectively reusing broke that has become defective due to defect detection, and an efficient paper manufacturing method using the paper machine.

[0013]

In order to achieve the above object, the paper quality monitoring apparatus of the present invention improves the background processing capacity by adopting the following configuration. That is, the paper quality monitoring device of the present invention is
The video camera and the light-emitting device are arranged to face each other with the running line of the wet paper web running in contact with at least one wire,
A video camera captures the wet paper as a static two-dimensional image. The image captured by the video camera is processed by the image processing device to remove at least one, preferably both, of the low frequency noise component of the grayscale variation and the periodic high frequency noise component of the grayscale variation. Then, the quality of the wet paper web is analyzed from the image processed by the image processing device, and the analysis result is displayed in time series on the display device.

Although the light emitting device irradiates the wet paper from the back side, it cannot always irradiate uniformly within the visual field range of the video camera. For this reason, irradiation unevenness may occur to some extent, but by removing the low-frequency noise component of the shading fluctuation as described above, it becomes possible to remove the background light amount fluctuation due to the irradiation unevenness of the light emitting device from the image. . Preferably, the background image including the irradiation unevenness is extracted by moving average processing, and the deviation of the average luminance between the extracted background image and the original image, that is, the background light amount variation is removed from the original image. This treatment is also effective, for example, when the traveling wire becomes dirty due to continuous use.

When the basis weight is low, the wire mark of the wire may appear in the image. By removing the periodic high-frequency noise component of the shading variation, the wire mark is erased from the image. It will be possible. Preferably, the periodic high frequency noise component is extracted by the two-dimensional Fourier transform, the specific frequency component is removed, and then the inverse Fourier transform is performed.

From the above, according to this quality monitoring device, it is possible to properly analyze the quality of paper without being influenced by the influence of disturbance such as uneven irradiation or wire marks. The analysis results are displayed on the display device in chronological order, so that the operator can easily grasp and evaluate the actual paper quality from the analysis results as a sensation and provide appropriate feedback to the operation. become.

More preferably, after the above processing is performed by the image processing apparatus, the image averaging processing is further performed. The averaging process is performed in predetermined pixel units according to the visual field range and resolution of the video camera. By this processing, random high frequency noise components in the image can be removed, and more appropriate paper quality analysis can be performed. Also,
As a display method by the display device, it is preferable to display the analysis result as a trend graph. According to such a display method, it becomes possible to visually and easily perform quality evaluation.

As a mechanical measure for reducing the influence of disturbance, it is effective to attach a light shielding cover to the video camera. It is also effective to attach a stain adhesion preventing cover to at least one, preferably both of the video camera and the light emitting device in order to reduce the influence of disturbance due to the adhesion of stain. Further, if at least one of the video camera and the light emitting device, preferably both, is provided with a retracting means for retracting the image capturing position to a retracted position off the wet paper web line, dirt can be prevented from being attached when not in use. can do. In this case, it is more effective to provide a dirt removing unit for removing dirt attached to the video camera or the light emitting device at the retracted position. If the dirt is removed at the retracted position as described above, the dirt may be dropped. It is also possible to prevent the wet paper from running out.

The video camera and the light emitting device are not limited to one set, and it is of course possible to arrange a plurality of sets. In particular, by disposing a plurality of sets in the width direction of the wet paper, it is possible to perform an appropriate quality analysis even when there is a variation in quality in the width direction. Further, instead of arranging a plurality of sets of video cameras and light emitting devices as described above, a video camera moving means for moving the video cameras in the width direction of the wet paper is provided, and the wet paper is moved while moving the video camera in the width direction. Still two-dimensional images may be captured at a plurality of positions in the width direction. In this way, the quality analysis can be performed at a plurality of positions in the width direction even by scanning in the width direction with one video camera. in this case,
It is preferable that the light emitting device is also movable in the width direction of the wet paper web by the light emitting device moving means and is moved in the width direction in synchronization with the movement of the video camera by the video camera moving device.

The above video camera and light emitting device are
When it is not necessary to make it movable, it can be embedded in the frame of the paper machine passed across the width of the wet paper web.
By embedding it in the frame in this way, it can be attached with high rigidity, and it is possible to prevent blurring in the imaging direction of the video camera and blurring of the optical axis of the light emitting device. As the light emitting device, a stroboscopic light emitting device that emits light intermittently in synchronization with image capturing by a video camera is suitable. When the wet paper web is running at high speed, it is necessary to increase the image capture speed of the video camera accordingly, but if you try to cope with this by increasing the shutter speed on the video camera side, the cost will increase. . However, with a strobe light emitting device, on / off of strobe light emission can be used instead of the shutter of a video camera, and the on / off speed of strobe light emission should be faster than the shutter speed of a video camera. Therefore, the cost can be kept low. Note that the stroboscopic light emitting device has a large irradiation unevenness because it is a point light source, but by removing the low-frequency noise component of the grayscale fluctuation as described above, the background light amount fluctuation due to the uneven irradiation of the stroboscopic light emitting device is also sufficiently removed from the image. be able to.

Further, it is highly effective to use a line camera as the video camera and a continuous light emitting device capable of continuous irradiation as the light emitting device. When a line camera is combined with a continuous light emitting device, it is not a point light source like a stroboscopic light emitting device but a parallel light source, so uneven irradiation is reduced. Also, when scanning in the paper width direction or continuously capturing images, it is easier to increase the shutter speed on the camera side by using continuous light emitting devices connected in the width direction rather than arranging multiple strobe light emitting devices side by side. become.
Even in the case of a continuous light emitting device, irradiation unevenness may occur due to slight misalignment of the optical axis from the video camera, etc., but of course the effect of uneven irradiation is eliminated by removing the low frequency noise component of the grayscale fluctuation as described above. Can be removed.

In particular, when the formation is monitored as the quality of the paper, the calculation device statistically processes the variation in the density of the image processed by the image processing device, and the formation index showing the superiority or inferiority of the formation of the wet paper. And the display device is configured to display the calculated formation index in time series (for example, by a trend graph). According to the quality monitoring device having such a configuration (hereinafter referred to as formation monitoring device), an appropriate formation index can be calculated without being affected by the influence of disturbance such as irradiation unevenness or wire marks. Since the calculated formation index is displayed on the display device in time series, the operator can easily grasp the actual formation as a sensation from the formation index, and appropriate feedback to the operation is possible. Become. The display on the display device is preferably displayed as a correlation graph of the formation index for each time series with the adjustment parameter of the paper machine that correlates with the formation of the wet paper. Examples of the adjustment parameter include the properties of the paper type and pulp chemicals, the concentration of the paper raw material liquid, the jet speed of the head box, the traveling speed of the wire, the dehydration pressure of the dehydrator or the pressing pressure of the blades constituting the dehydrator. To be According to such a display, the operator can at a glance grasp the degree of influence of each adjustment parameter on formation adjustment or the guideline for adjustment.

The present invention also provides a paper machine using the above-mentioned formation monitoring device and a method for producing paper using the paper machine. This paper machine is a paper machine provided with a former section for forming wet paper while dewatering a paper raw material liquid ejected from a headbox on a wire or between a pair of wires by one or more dewatering devices. An adjusting device that adjusts at least one of the exemplified adjusting parameters is provided, and an image capturing unit including a video camera and a light emitting device that constitutes the above-mentioned formation monitoring device is provided in the former section. Then, using the paper machine having such a configuration, the parameters are adjusted by the adjusting device so that the formation index displayed on the display device during papermaking becomes a desired value, and the desired formation index is obtained. Paper is manufactured by the value. In addition, adjustment of the parameters,
It is performed so that the formation index becomes optimum within the allowable range of other physical properties of paper.

According to the paper machine having the above-described structure and the method for producing paper using the paper machine, the operator can easily understand the formation by feeling the formation index displayed on the display device in time series. As a result, proper feedback to the parameter adjustment by the adjusting device is possible, and as a result, it becomes possible to easily manufacture the optimally texture-adjusted paper. Further, since the texture of the paper is estimated from the wet paper in the former part, the texture change with respect to the adjustment parameter can be grasped instantly. Therefore, it is possible to quickly adjust to the optimal formation and reduce the risk of paper breakage. It is also effective for improving the operator's skills.

The image capturing unit may be provided at a plurality of positions along the running line of the wet paper web. By providing multiple image capture units along the travel line in this way, it is possible to monitor the formation at each stage, and by feeding back the monitoring results to the parameter adjustment by the adjustment device, a more optimal location can be obtained. It becomes possible to adjust the total.

More preferably, the paper machine further comprises a discharging device for discharging the wet paper from the traveling line between the former part and the dryer part inlet. Then, using the paper machine having such a configuration, the parameters are adjusted by the adjusting device so that the formation index displayed on the display device during papermaking becomes a desired value, until the desired formation index is obtained. During the period, the wet paper is discharged from the running line by the discharging device, and when the desired formation index is obtained, the wet paper is returned to the running line and papermaking is performed with the parameter value that gives the desired formation index. To manufacture.

According to the paper machine having such a structure and the method for producing paper using the paper machine, when the paper machine is started up, when the brand is changed, or immediately after the paper is cut, the wet paper is wetted upstream of the dryer section. Since it is possible to adjust the optimal formation while ejecting the paper, it is possible to suppress the risk of paper breakage far more than the adjustment while winding the paper on the reel and the effort for dealing with it. Further, since the broke paper discharged during the adjustment is reused in the wet paper state, the pulp property is hardly deteriorated and can be effectively reused as a high-quality raw material.

Further, in a multi-layer papermaking machine such as paperboard, when it is desired to create quality by paying attention only to the formation state of the surface layer, the dehydration unit for forming the surface layer may be provided with the above image capturing unit. The quality of only the surface layer can be improved accurately. Further, by installing the image capturing unit at a plurality of locations including the dehydration unit that forms the surface layer, for example, when a problem occurs in the quality of the surface layer, when the formation state in the surface layer and the multilayer in the subsequent flow By comparing with the formation state, it is possible to identify at which place the paper quality is deteriorated and the quality can be efficiently improved.

When defects such as dust spots, foreign substances, scratches and breaks that impair the homogeneity of the product are monitored as the quality of the paper, the image processed by the image processing device is filtered to obtain a wet paper web. And the display device is configured to display the analyzed position in the width direction of the defective portion in time series. According to the quality monitoring device having such a configuration (hereinafter referred to as a defect monitoring device), the presence of a defective portion in the wet paper can be properly analyzed without being influenced by the influence of disturbance such as irradiation unevenness and wire marks. be able to. Since the analyzed position in the width direction of the defective portion is displayed on the display device in time series, the operator can easily grasp the actual defect state as a sensation from the analysis result, and the proper feedback to the operation can be obtained. It will be possible. Preferably, the arithmetic unit is configured to identify the defect type as well as the defect type, and the defect type is displayed together with the width direction position of the defect unit on the display device. The defect type can be specified based on the shape of the detected defect portion. By displaying the defect types together, it becomes possible to more easily visually perform the defect evaluation.

Further, the correspondence relationship between the widthwise position of the defective portion detected by the former portion and the widthwise position of the defective portion detected by another part is calculated by a calculation device in consideration of the amount of paper draw and shrinkage. It is also preferable to obtain and display the position of each defective portion in the width direction on the display device in an overlapping manner. In this case, more preferably, the arithmetic unit estimates the defect occurrence point on the papermaking line based on the result of superimposing a plurality of defect parts, and displays the estimated defect occurrence point on the display device. In this way, by displaying the estimation result of the defect occurrence point,
Adjustment work by the operator becomes extremely easy. Also,
Even if the estimation result is not displayed, the position in the width direction of each defective portion is displayed in an overlapping manner so that the operator can easily specify the defect occurrence location. Further, it is preferable that the detection sensitivity of the defective portion by the arithmetic unit can be adjusted by the sensitivity adjusting means. Since the tolerance of defects varies depending on the paper type, it is possible to achieve both quality and stable operation by allowing the detection sensitivity to be adjusted according to the usage situation.

The present invention also provides a paper machine using the above-mentioned defect monitoring device and a paper manufacturing method using the same. This paper machine is a paper machine provided with a former section for forming wet paper while dewatering a paper raw material liquid ejected from a headbox on a wire or between a pair of wires by one or more dewatering devices. The defect monitoring device is provided, and the image capturing unit including the video camera and the light emitting device that constitutes the defect monitoring device is provided in the former section. Then, using a paper machine having such a configuration, the location of the defect on the papermaking line is identified based on the widthwise position of the defect portion displayed on the display device during papermaking, and the identified location of the defect is adjusted. Papermaking is carried out to produce paper.

According to the paper machine having the above-mentioned structure and the paper manufacturing method using the same, the operator is present on the wet paper web by observing the widthwise position of the defective portion displayed on the display device in time series. Since defects can be easily grasped as a sensation, it becomes easy to identify where defects occur on the papermaking line, and it becomes possible to quickly produce defect-free paper and reduce the risk of paper breaks. it can.

The image capturing unit may be provided at a plurality of locations along the running line of the wet paper. By providing multiple image capturing units along the travel line in this way, it is possible to monitor the presence or absence of defects at each stage, and by feeding back the monitoring results to the identification of the defect occurrence point, there is no defect. The paper can be manufactured more quickly.

More preferably, the paper machine further comprises a discharging device for discharging the wet paper from the traveling line between the former part and the dryer part inlet. Then, using the paper machine having such a configuration, the wet paper is discharged from the traveling line by the discharging device while the defective portion is displayed on the display device, and when the defective portion is not displayed, the wet paper is returned to the traveling line. Papermaking is carried out to produce paper. According to the paper machine having such a configuration and the paper manufacturing method using the paper machine, since the broke discharged during the adjustment is reused in the wet paper state, there is almost no deterioration of the pulp property and the quality of the raw material is high. Can be effectively reused as

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a paper quality monitoring device as an embodiment of the present invention. The quality monitoring device is a video camera 1, strobe (strobe light emitting device) 2, camera amplifier 3, strobe amplifier 4
And a computer 6. Of these, the image capturing unit consisting of the video camera 1 and the strobe 2 is arranged in the former section of the paper machine and is connected online to the computer 6 arranged in the operation room. The camera amplifier 3 and the strobe amplifier 4 may be attached to the video camera 1 and the strobe 2, or may be attached to the computer 6.

As the video camera 1, for example, a CCD camera can be used. The video camera 1 is installed above the wet paper web 10 that travels with the wire 20 in the former section, and the strobe 2 is installed so as to face the video camera 1 with the wire 20 and the wet paper web 10 sandwiched therebetween. Further, the optical axis of the strobe 2 and the image pickup direction of the video camera 1 are adjusted to coincide with each other. In addition, video camera 1
It is also possible, of course, to install the underside of the wet paper web 10 and the strobe 2 above.

The video camera 1 and the strobe 2 are designed to operate simultaneously upon receiving a trigger signal from the computer 6. Specifically, the trigger signal is periodically transmitted from the image capturing board 6a of the computer 6 to the camera amplifier 3 and the strobe amplifier 4. Upon receiving the trigger signal, the camera amplifier 3 transmits a capture signal to the video camera 2, and the strobe amplifier 4 transmits a light emission signal to the strobe 2. The strobe 2 emits light intermittently in synchronization with the light emission signal, and the video camera 2 synchronizes with the capture signal in the wet paper web 10.
Is captured and captured as a static two-dimensional image. The still two-dimensional image of the wet paper web 10 captured by the video camera 2 is transmitted as an image signal to the camera amplifier 3, and is further captured by the computer main body (image processing device, arithmetic device) 6b from the image capturing board 6a. The computer body 6b processes the captured image to calculate the formation index of the wet paper 10,
A function of displaying the calculated formation index on the monitor (display device) 6c, and a function of analyzing the existence of a defective portion on the wet paper 10 and displaying the analyzed position in the width direction and the defect type on the monitor 6c. have. The function of the computer 6 will be described in detail later. In FIG. 1, only one set of the video camera 1 and the strobe 2 is provided, but it is of course possible to provide a plurality of sets of image capturing units in the width direction of the running line of the wet paper 10. In this case, if the processing capacity of the computer 6 is sufficient, it is of course possible for one computer 6 to process image signals from a plurality of sets of image capturing units.

FIG. 2 is a view showing a concrete mounting structure of the wet paper 10 of the video camera 1 and the strobe 2 near the running line. The mounting structure described here is only for the video camera 1 and the strobe 2 according to the present invention.
However, the present invention is not limited to this and is merely an example of a mounting structure that can be adopted. Here, the video camera 1 is surrounded by a box 7 and is suspended from the retract arm 8 together with the box 7. Box 7 is
It is a cylindrical and colored cover member, and it has a stain prevention function that prevents the video camera 1 from being soiled by the stock liquid that scatters from the running wet paper web 10, and prevents external noise light from entering the video camera 1. It has a light-shielding function. However, a transparent shield is attached to the bottom surface of the box 7 in order to ensure a stain prevention function while allowing light within the visual field range of the video camera 1 to pass through.

The retracting arm 8 can be expanded and contracted in the axial direction by an actuator (not shown) (or can be rotated around a predetermined point outside the traveling line).
It has become. The video camera 1 is at the position (image capture position) shown in FIG. 2 during monitoring, but when the monitoring is completed, the retractable arm 8 contracts (or swivels).
As a result, the wet paper web 10 is withdrawn together with the box 7 to the outside of the traveling line (withdrawal position). In this way, by installing the video camera 1 on the running line of the wet paper web 10 only during monitoring and evacuating it outside the running line when finished,
It is possible to minimize the adhesion of dirt to the box 7.

On the other hand, the strobe 2 is a machine frame 1 which is stretched across the running line of the wet paper web 10 in the width direction.
Embedded in 8. By being embedded in the mechanical frame 18 as described above, it is possible to prevent the optical axis from being displaced or from being shaken at the time of imaging. As with the video camera 1, the strobe 2 may be covered with a cover for preventing dirt, and the strobe 2 may reach the retracted position outside the traveling line of the wet paper 10 at the end of monitoring like the retractable arm 8 of the video camera 1. It is also possible to provide a retracting means for retracting. Further, it is of course possible to embed the video camera 1 in the machine frame 18.

FIG. 3 is a view showing another example of a concrete mounting structure in the vicinity of the running line of the wet paper 10 of the video camera 1 and the strobe 2. Here, both the video camera 1 and the strobe 2 are configured to be movable in the width direction of the running line of the wet paper 10. The video camera 1 is suspended on a rope 11 for camera scanning that is stretched across the width of the wet paper web 10 in the width direction. The camera scanning rope 11 is wound around the pulley 12 and two reciprocating lines are used for the wet paper 1.
The video camera 1 is fixed to one of them through a fixed rope 13 and is hooked to the other by a hook 14. As a result, by rotating the pulley 12 and the camera scanning rope 11 by an actuator (not shown), the video camera 1 moves so as to cross the running line of the wet paper 10 in the width direction.

On the other hand, the strobe 2 is arranged on a strobe scanning rail 15 laid in the width direction below the running line of the wet paper 10. An actuator (not shown) is attached to the strobe 2 so that the strobe 2 can be moved along the strobe scanning rail 15 so as to cross the traveling line of the wet paper 10 in the width direction. The strobe scan rail 15 and the camera scan rope 11 are installed parallel to each other, and the camera scan rope 11 is also installed.
The actuator for rotating the strobe 2 and the actuator for moving the strobe 2 along the strobe scanning rail 15 are synchronized. As a result, the video camera 1 and the strobe 2 can be moved in the width direction of the running line of the wet paper web 10 while maintaining the positional relationship in which the wet paper web 10 and the wire 20 are opposed to each other. It is possible to scan in the direction.

According to such a mounting structure, it is not necessary to arrange a plurality of sets of the video camera 1 and the strobe 2 in the width direction. Further, if the wet paper web 10 can be moved to the outside of the traveling line, it is possible to retreat to the outside of the traveling line at the end of monitoring to minimize the adhesion of dirt, as in the structure shown in FIG. The moving means for moving the video camera 1 and the strobe 2 in the width direction is not limited to the rope as shown in FIG. 3, and various mechanisms such as a screw rod and a linear actuator may be adopted. You can Further, here, the strobe 2 is also moved in synchronization with the video camera 1, and it is preferable that the strobe 2 and the strobe 2 move while maintaining the positional relationship in this way. It does not have to be perfectly synchronized, and it need not be a complete translation. Further, the position of the strobe 2 may be fixed in some cases. This is because, according to the present invention, it is possible to correct the irradiation unevenness by the strobe 2 in the image processing as will be described later. This is because the influence can be eliminated.

By the way, as described above, by evacuating the video camera 1 to the outside of the running line of the wet paper 10 at the end of the monitoring, it is possible to minimize the adherence of dirt to the video camera 1, but the adhered dirt is minimized. Since it cannot be left alone, it must be removed by some means. FIG. 4 exemplifies a stain removing means therefor. Here, by blowing air from the blow box 16 toward the transparent shield 7b on the bottom surface of the box 7, the stain attached to the transparent shield 7b is removed. There is. At the same time, the box 7 is rotated at a high speed around the rotary shaft 7a by a motor (not shown) so that the dirt on the side surface of the box 7 is also blown away and removed. Of course, these are examples of the stain removing device, and it is possible to spray a water stream or scrape the stain with a wiper. Note that the dirt removal work is performed at the retracted position of the wet paper web 10 outside the traveling line. When the stains are removed on the running line, the removed stains may drop on the wet paper 10, which not only deteriorates the quality of the product but also causes a break in the post process. Because it will be. Of course, the above dirt removing means can be applied not only to the video camera 1 but also to the strobe 2.

Next, the specific arrangement of the image capturing unit consisting of the video camera 1 and the strobe 2 on the paper machine will be described. Although the image capturing unit is attached to the former section of the paper machine as described above, the structure of the former section is not a single structure but various structures exist depending on the papermaking method. Fig. 5 shows the structure of the former part (twin wire former) for one-layer papermaking, Fig. 6 shows the structure of the former part for four-layer papermaking, and Fig. 7
Shows the structure of the two-layer former.
Hereinafter, an arrangement example of the image capturing units in the former section shown in FIGS. 5 to 7 will be described, but this is merely an example, and the actual arrangement of the image capturing units is not limited to the following arrangement.

First, in the former portion having the structure shown in FIG. 5, the loop-shaped bottom wire 20 and the top wire 21 are synchronously rotated while being partially guided while being guided by a plurality of guide rolls. Then, the raw material liquid 23 is ejected from the head box 22 toward the inlet portion where the bottom wire 20 and the top wire 21 come into contact with each other. The raw material liquid 23 ejected from the head box 22 is dehydrated by a plurality of dehydrating devices 24, 25 and 26 while being sandwiched between the wires 20 and 21, thereby forming a wet paper web. The formed wet paper is the bottom wire 2
0 and the top wire 21 are attached to the bottom wire 20 side at the exit portion where they are separated from each other, and are further dehydrated on the bottom wire 20 by a dehydration device 27 and then transferred to a press unit (not shown). Here, the image capturing unit (the video camera 1 and the strobe 2) is arranged on the upstream side of the dehydrating device 27 so as to image the wet paper on the bottom wire 20.

In the former part having the structure shown in FIG. 6, a plurality of bottom wires 33, 3 are provided for one top wire 43.
6, 39, and 42 are sequentially arranged in the rotation direction of the top wire 43, and each part is in contact with each other and synchronously rotates. Then, head boxes 31, 34, 3 for supplying the raw material liquid are respectively provided at the inlets where the top wire 43 and the bottom wires 33, 36, 39, 42 come into contact with each other.
7, 40 are provided. Further, dehydrating devices 32, 35, 38, 41 are provided at the contact portions between the top wire 43 and the bottom wires 33, 36, 39, 42, respectively. Each dehydrator 32, 35, 38, 41 has a corresponding bottom wire 33, 36, 39, 42 and top wire 43.
Together with this, it forms a dehydration unit.

With such a structure, first, the raw material liquid ejected from the head box 31 is dehydrated by the dehydrating device 32 while being sandwiched between the wires 43 and 33, and the surface layer (first
A wet paper web to be a layer is formed. Next, the raw material liquid is supplied from the head box 34 onto the surface wet paper, and the wire 4
The second layer of the wet paper is formed by being dehydrated by the dehydrating device 35 while being sandwiched between 3, 36. Subsequently, the raw material liquid is supplied from the head box 37 onto the second layer, and is dehydrated by the dehydrating device 38 while being sandwiched between the wires 43 and 39, thereby forming the third layer of the wet paper, and further, the third layer. The raw material liquid is supplied from the head box 40 onto the layer,
The fourth layer of wet paper is formed by being dehydrated by the dehydration device 41 while being sandwiched between the wires 43 and 42. As a result, the wet paper web is attached to the bottom wire 42 side at the outlet where the wires 43 and 42 are separated, but at this time, four wet paper webs from the surface layer to the fourth layer are formed on the bottom wire 42. Here, the image capturing unit (the video camera 1 and the strobe 2) is first connected to the top wire 43 and the fourth wire.
One set is arranged at the outlet with respect to the bottom wire 42 (the outlet of the fourth dehydration unit) so as to image the four-layer wet paper on the fourth bottom wire 42. Further, another set is also arranged at the outlet of the top wire 43 and the first bottom wire 33 (the outlet of the first dehydration unit) so that the surface wet paper on the top wire 43 can be imaged. There is. The reason why the surface wet paper is imaged in this manner is that the surface is a portion particularly visible to the consumer, and the texture of the surface has a great influence on the quality of the entire product.

Although the image capturing unit is provided in each of the first and fourth dehydrating units here,
An image capturing unit may also be provided in the third dehydrating unit. When multiple image capturing units are provided along the running line in this way, the formation at each stage can be monitored, and by feeding back the monitoring results, more optimal formation adjustment is possible. Become. For example, when a problem occurs in the quality of the surface layer, the quality of the surface layer is deteriorated by comparing the formation state in the surface layer with the formation state in the case of a multi-layer in the subsequent flow at which combining place. It is possible to easily identify whether or not there is.

In the former portion having the structure shown in FIG. 7, the top wire 55 and the bottom wire 52 are synchronously rotated while partially contacting each other, and the raw material liquid for the surface layer is supplied from the head box 53 onto the top wire 55. Then, the raw material liquid for the lower layer is supplied from the head box 50 onto the bottom wire 52. Both the top wire 55 and the bottom wire 52 are provided with a horizontal traveling area, and the raw material liquids supplied from the respective head boxes 53, 50 travel on these horizontal traveling areas on the respective wires 55, 52 respectively for dehydration equipment groups. It is dehydrated by 54 and 51. Then, the surface wet paper formed on the top wire 55 and the lower wet paper formed on the bottom wire 52 are combined in the contact region of the top wire 55 and the bottom wire 52, whereby a two-layer wet paper is obtained. It is formed. The formed two-layer wet paper web is attached to the bottom wire 52 side at the exit portion where the bottom wire 52 and the top wire 55 separate from each other, and is transferred to a press unit (not shown). Here, one set of image capturing units (video camera 1 and strobe 2) is first arranged at the exits of the top wire 55 and the bottom wire 52, and images the two-layer wet paper on the bottom wire 52. Has become. Further, another set is also arranged on the top wire 55 on the downstream side of the dehydration device group 54, and the surface wet paper on the top wire 55 is imaged.

Next, the functions of the computer 6 are shown in FIG.
And it demonstrates in detail using FIG. FIG. 8 is a flowchart showing the flow of calculating the formation index by the computer 6. First, the computer 6 executes step S
In 10 and S20, the video camera 1 and the strobe 2 are operated in synchronization. Then, in step S30, the still two-dimensional image of the wet paper web 10 captured by the video camera 1 is captured by the computer body 6b via the image capture board 6a. The computer main body 6b inspects a part of the captured image for a high contrast part (step S40). In this inspection, for example, when the brightness distribution range of the previous image is exceeded during scanning of the image, or when the grayscale variation amount changes abruptly, it is determined that there is a specific high contrast region. When only the specific region has high contrast, it is considered that the wet paper web 10 has a defect, and in that case, the processing of step S130 and subsequent steps described later is performed.

On the other hand, the background light amount variation removing process (step S50) and the periodic noise removing process (step S60) are performed on the image determined to be normal in step S40. The processing of steps S50 and S60 is shown in FIG.
In the above, either one is selected, but both processes may be sequentially performed, and it is more preferable to perform both processes in such a manner. The contents of each process will be described in detail below with reference to FIGS. 9 and 10.

The background light amount variation removing process in step S50 is a process for removing the background light amount variation due to the uneven illumination (light emission unevenness) of the strobe 2 from the image. Strobe 2
Is a point light source, it cannot illuminate the entire field of view of the video camera 1 uniformly, and a background light amount variation occurs such that it gradually becomes dark in the concentric direction or from one side to the other side. Appears as a low-frequency noise component of grayscale fluctuation in the image captured by the video camera 1. Therefore, the computer main body 6b as the image processing apparatus eliminates the influence of the disturbance due to the uneven irradiation by removing the low frequency noise component of the grayscale fluctuation from the original image. Specifically, the computer main body 6b first performs a moving average process, which is a known method, on the original image as shown in FIG. By the moving average process, the high frequency component of the grayscale variation is leveled and the background image is extracted. This background image contains low-frequency noise components that have not been averaged by the moving average process, that is, irradiation unevenness as a background light amount variation (above, step S
501). Next, the computer main body 6b performs step S5.
As 02, the background image extracted in step S501 is subtracted from the original image, and the average luminance of the original image is added to the deviation. In other words, the deviation of the average luminance between the extracted background image and the original image, that is, the background light amount variation is removed from the original image. By the above processing, an image in which the fluctuation of the background light amount due to the uneven irradiation of the strobe 2 is removed is obtained.

The periodic noise removing process in step S60 is a process for removing the wire mark of the wire 20 from the image. Since the wire 20 is knitted in a mesh shape, a mesh-like shadow is formed on the wet paper 10 when the wire 20 and the wet paper 10 are seen through. This appears as a periodic high-frequency noise component of grayscale fluctuation in the image captured by the video camera 1. Therefore, the computer main body 6b as the image processing apparatus removes the wire mark of the wire 20 from the image by removing the periodic high-frequency noise component of the grayscale variation from the original image. Specifically, first, the computer main body 6b sends an FF to the original image as shown in FIG.
Two-dimensional Fourier transform by T is performed. The relationship between each frequency and intensity is derived by the two-dimensional Fourier transform as shown in the graph in the figure, and the periodic noise appears as a peak (above, step S601). Next, computer body 6
b is, after removing the specific frequency component that gives the peak intensity from the two-dimensional Fourier transform image in step S602,
Inverse Fourier transform is performed. An image in which the wire mark of the wire 20 is erased is obtained by the above processing.

In this way, with respect to the image formed by removing the background light amount fluctuation and the wire mark of the wire 20 due to the uneven irradiation of the strobe 2, the computer main body 6b
It is inspected again whether there is a part with high contrast in a part (step S70). This inspection may be performed only in step S40 immediately after the image is captured as described above, but if the background light amount variation due to the uneven irradiation or the periodic noise due to the wire mark is large, the defect detection accuracy is reduced as well as the formation. . Therefore, in this embodiment, the defect inspection is performed again after the background light amount variation and the wire mark are removed and after the processing by the averaging filter described later. When only the specific region has high contrast, it is considered that the wet paper web 10 has a defect, and in that case, the processing of step S130 and subsequent steps described later is performed.

On the other hand, for the image determined to be normal in step S70, the computer main body 6b as the image processing apparatus, as shown in FIGS. 8 and 11, changes the background light amount due to uneven irradiation of the strobe 2. The image from which the wire mark of the wire 20 is removed is averaged by the averaging filter (step S80). This averaging process is performed as necessary depending on the visual field range and resolution of the video camera 1. Although the size of the averaging filter depends on the resolution, a CCD camera having a general resolution preferably performs the averaging process in a unit of 1 mm × 1 mm square. By this averaging process, random high-frequency noise components of grayscale fluctuations in the image can be smoothed, and an image in which the influence of randomly added noise is eliminated can be obtained.

After the averaging process, the computer main body 6b
Inspects again whether there is a part with high contrast as described above (step S90). When only the specific region has high contrast, it is considered that the wet paper web 10 has a defect, and in that case, the processing of step S130 and subsequent steps described later is performed. On the other hand, if the determination in step S90 is normal, step S10
The processing after 0 is performed.

In steps S100 to S120, the computer main body 6b functions as an arithmetic unit, and in step S5
The density variation of the image from which the influence of the disturbance is removed by the processing of 0, S60, and S80 is statistically processed. Specifically, the luminance distribution of all the pixels forming the image is obtained (step S10).
0). Then, the standard deviation of the obtained brightness distribution is obtained, and the formed value is used as an index indicating the superiority or inferiority of the formation, that is, the formation index, and the formation is digitized (step S110).
The formation index calculated by the computer body 6b is displayed on the monitor 6c as a trend graph as shown in FIG. 11 or 12 (step S120). In addition,
When a plurality of video cameras 1 are arranged in the width direction of the wet paper 10 or the video camera 1 scans in the width direction, image processing and formation index calculation are performed for each measurement position and calculated. The formation index is also displayed as a separate trend graph for each measurement position.

On the other hand, if it is determined in steps S40, S70, and S90 that there is a high contrast specific area, the computer main unit 6b proceeds to step S
The processing of 130 to S160 is performed. First, step S13
At 0, a threshold value for the binarization process is calculated. A general method can be used as the threshold value calculation method, and a detailed description thereof will be omitted because the threshold value calculation method itself is not the gist of the present invention. For example, even if preset brightness is used as the threshold value. Of course, the threshold value may be calculated from the change in the shading variation amount. Further, the threshold may be calculated from the distribution characteristic determination such as the discriminant distribution method or the mode method, or the threshold may be calculated from the edge gradient. However, in any case, it is preferable that the threshold value can be adjusted so that the detection sensitivity of the defect can be adjusted by the operation of the operator. The tolerance of defects differs depending on the paper type, and if the detection sensitivity is low, unacceptable defects will be overlooked and the quality will be degraded.However, if the detection sensitivity is higher than necessary, the allowable defects will also be detected. Excessive waste paper may be generated due to removal of the cause of occurrence, or the paper machine may be stopped. Therefore, by making it possible to adjust the detection sensitivity according to the usage situation, it is possible to achieve both quality and stable operation.

In step S140, the image is binarized using the calculated threshold value. As a result, the defect target portion is extracted from the image. FIG. 13A shows an image of a normal wet paper and a graph showing a distribution of luminance values of pixels forming the image. As shown in FIG. 13A, in the case of a normal wet paper image, the luminance values are gently distributed around the average value. On the other hand, when there is a defect, for example, when there is a dark-colored defect such as a foreign matter as shown in FIG. 13B, the dark-colored side from the average value is also shown as shown in the graph of FIG. 13B. A small peak occurs, and the peak portion on the dark side corresponds to the defective portion. On the other hand, for example, in FIG.
When there is a light-colored defect such as a pinhole as shown in FIG. 13C, a small peak appears on the light-colored side of the average value as shown in the graph of FIG. The peak part of corresponds to the defective part. Therefore, the computer main body 6b as the arithmetic unit sets the threshold value in the valley between the peaks in step S130, and in the binarization processing in step S140, the dark color side is more than the threshold value in the dark color defect and the light color defect is more than the threshold value. The light color side is extracted as a defect portion.

Next, the computer main body 6b calculates the shape feature amount of the defect extracted in step S140. Then, the defect type of the defective portion is specified from the calculated shape feature amount (step S150). A method of identifying a defect type using a shape feature amount is publicly known, and detailed description thereof is omitted because it is not the gist of the present invention. For example, area, circumference, spread / circularity, ferret diameter, and contrast Etc., or a combination thereof can be used as the shape feature amount.
The extracted defective portion is displayed on the monitor 6c by a trend graph as shown in FIG. 14 (step S1).
60). In the trend graph, the position of the defective portion in the width direction (position in the width direction of the wet paper web 10) is displayed together with the defect type. Here, the case where pinholes, bugs, dirt, holes, and streaks are present as defects is shown. In FIG. 14, the defective portions indicated by black squares indicate dark defects, and the defective portions indicated by open squares indicate bright defects. In addition, when detecting the presence or absence of a defective portion in the wet paper web 10 as described above, the video camera 1 is used.
It is preferable that the entire width of the wet paper 10 can be inspected by arranging a plurality in the width direction of 0 and scanning the video camera 1 in the width direction.

As described above, according to the above quality monitoring device, an appropriate formation index can be calculated without being affected by the influence of disturbance such as irradiation unevenness and wire marks.
Then, the calculated formation index is displayed in time series on the monitor 6c using a trend graph, so that the operator can easily grasp the actual formation as a sense from the formation index and it is appropriate for the operation. Feedback is possible.
It should be noted that the moving average process used as the method for removing the low-frequency noise component of the grayscale variation in step S50 and the two-dimensional Fourier used as the method for removing the periodic high-frequency noise component of the grayscale variation in step S60. The conversion is merely an example of a method that the present invention can adopt, and the present invention is not limited to these.

Further, according to the quality monitoring device described above, the presence of the defective portion in the wet paper can be properly analyzed without being affected by the influence of disturbance such as irradiation unevenness and wire marks. The analyzed widthwise position of the defect portion is displayed in time series on the monitor 6c together with the defect type using a trend graph, so that the operator can easily grasp the actual defect state as a sensation from the analysis result. , Appropriate feedback to the operation becomes possible.
Although the defect type of the defective portion is also displayed in FIG. 14,
If at least the position of the defective portion in the width direction is specified, it becomes easy to specify the location of the defect on the papermaking line.

Finally, a method for producing paper by a paper machine equipped with the above quality monitoring device will be described. The parameters that affect the formation of paper include the concentration of the paper raw material liquid, the jet speed of the head box (jet speed), the traveling speed of the wire, and the dehydration pressure of the dehydrator. Of these, the ejection speed of the headbox and the traveling speed of the wire are correlated, and generally, the ratio of the ejection speed (J) of the headbox to the traveling speed (W) of the wire (J / W ratio) is treated as a parameter. Be seen. For example, in the former section shown in FIG. 5, the concentration of the raw material liquid 23, the J / W ratio between the wires 20 and 21 and the head box 22, and the dehydration pressure of the dehydration devices 24, 25 and 26 are parameters for adjusting the formation. Becomes Each parameter is adjusted by operating various adjustment devices such as an opening adjustment device of the head box 22 and a jet pressure adjustment device. These adjustment devices can be remotely operated by an operation panel arranged in the operation room. The operator adjusts the parameters so that the formation index becomes a desired value while visually observing the trend graph of the formation index displayed on the monitor 6c, and the paper making is performed with the parameter value at which the desired formation index is obtained. I do.

Here, FIG. 15 is a characteristic diagram showing the influence of the J / W ratio on the aspect ratio of tensile strength, and FIG. 16 is a characteristic diagram showing the influence of the opposing dewatering blade linear pressure on the interlayer strength. is there. The operator selects parameters (here, the J / W ratio and the opposing dewatering blade linear pressure) such that the formation index approaches the best within the allowable range of the other paper properties shown in these characteristic diagrams. In the trend graph of FIG. 12, the J / W ratio is first adjusted to select the J / W ratio (1.06) that gives the best formation index, and then the opposing dewatering blade linear pressure is adjusted. The linear pressure (0.6) that gives the best combined index is selected. As a result, the aspect ratio of the tensile strength and the interlaminar strength can be adjusted to an optimum formation while being kept within the allowable range.

Further, according to the above quality monitoring apparatus, the position of the defective portion in the width direction is displayed on the monitor 6c together with the defect type in a trend graph as shown in FIG. The operator identifies the occurrence position and the cause of the defect on the papermaking line from the information such as the position in the width direction of the defect portion displayed on the monitor 6c, the defect type, the defect occurrence period, and the like. Then, after removing the cause or adjusting the point considered to be the cause, the papermaking is restarted, and the monitor 6c checks whether or not there is a defect. The above operation is repeated, and when the defect is resolved, papermaking as the main operation is started.

As described above, according to the paper machine according to the present embodiment and the paper manufacturing method using the same, the operator can easily see the formation index by observing the formation index displayed in time series on the monitor 6c. Because you can grasp
Appropriate feedback to the parameter adjustment by the adjusting device is possible, and as a result, optimally texture-adjusted paper can be easily manufactured. Particularly, since the formation is estimated from the wet paper on the former portion, the formation change with respect to the adjustment parameter can be grasped instantly. Therefore, it is possible to quickly adjust to the optimal formation and reduce the risk of paper breakage. Further, since the adjustment result is promptly fed back, it is easy to learn the adjustment technique, which is effective for improving the skill of the operator.

Further, according to the paper machine and the paper manufacturing method using the same according to the present embodiment, the widthwise position of the defective portion existing in the wet paper is displayed on the monitor 6c in time series together with the defect type. Therefore, since the operator can easily grasp the defects existing in the wet paper as a sensation, it becomes easy to identify the location of the defects on the papermaking line,
It is possible to quickly manufacture a paper without defects and reduce the risk of paper breakage.

Although the wet paper determined to be defective by the formation evaluation and the wet paper determined to be defective are discharged as spoiled paper,
In the paper machine according to the present embodiment, the waste paper is discharged and disposed at any position from the former section to the dryer section inlet. The broke can be discharged by cutting the wet paper in the width direction with a water jet or the like and dropping it below the traveling line when the lower surface of the wet paper is free. However, the structure of the discharging device that discharges the damaged paper is not limited to this. In this way, the wet paper can be discharged as broke before it is dried in the dryer, so that the formation can be accurately estimated from the wet paper on the former as described above, and the defect can be detected. Because it can be accurately detected. Therefore, according to the paper machine according to the present embodiment and the paper manufacturing method using the paper machine, the wet paper is provided on the upstream side of the dryer section at the time of start-up of the paper machine, at the time of changing the brand, or immediately after the paper break. Since it is possible to adjust to an optimal formation without any defects while discharging the sheet, it is possible to suppress the risk of paper breakage far more than the adjustment while winding the paper on the reel and the effort for dealing with it. Further, since the broke discharged during the adjustment is reused in the wet paper state, there is almost no deterioration in the pulp property and there is an advantage that it can be effectively reused as a high-quality raw material.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, although the strobe light emitting device is provided as the light emitting device in the above-described embodiments, a continuous light emitting device capable of continuous irradiation may be provided instead of the strobe light emitting device. In this case, it is preferable to use a line camera as the video camera. By combining a continuous light emitting device with a line camera, it is possible to obtain substantially parallel light, and it is possible to reduce uneven irradiation as compared with a strobe light emitting device which is a point light source. However, even in this case, it is quite possible that the irradiation unevenness may occur due to the deviation of the optical axis from the line camera. Therefore, it is effective to remove the low frequency noise component of the grayscale fluctuation by the image processing as described above.

When the strobe light emitting device and the continuous light emitting device are compared, the strobe light emitting device can use on / off of strobe light emission instead of the shutter of the video camera, and the on / off speed of strobe light emission is different from that of the video camera. Since it is possible to easily increase the shutter speed rather than to increase the shutter speed, there is an advantage that the cost can be kept low when coping with the speeding up of wet paper. On the other hand, the continuous light emitting device has an advantage that it can reduce uneven irradiation as described above. In addition, when scanning a wet paper web running at high speed in the width direction or continuously capturing images, a continuous light emitting device and a line extending in the paper width direction are provided rather than arranging a plurality of strobe light emitting devices side by side. It is easier to increase the shutter speed on the line camera side using a camera, and the cost can be kept low. In a low-speed paper machine such as a general multi-layer paper machine, an image capturing unit in which a general video camera is combined with a continuous light emitting device can sufficiently cope.

Further, the quality monitoring apparatus according to the above-mentioned embodiment has two functions, namely, a function as a formation monitoring apparatus and a function as a defect monitoring apparatus, but only one of the functions is provided. It may be provided. Alternatively, two functions may be provided so that the operator can arbitrarily select one of the functions.

When the above quality monitoring device is used as a defect monitoring device (defect detection device), one or a plurality of defect detections are performed at any position from the press part to the reel part in addition to the former part. It is preferable to arrange the device. If only one is arranged, it may be arranged between the dryer section and the calendar section (between the after dryer section and the calendar section if there is a size press section). By arranging a plurality of defect detection devices along the papermaking line in this manner, it becomes possible to accurately identify the location of the defect on the papermaking line by associating the detection data of each defect detection device. For example, when a defect that cannot be detected by the former unit is detected by the press unit, it can be specified that the defect has occurred in the press unit. In this case, the defect detection device installed at a place other than the former portion does not necessarily have to be the quality monitoring device described above, and a general defect detection device may be used.

[0074]

As described above in detail, according to the paper quality monitoring apparatus of the present invention, the light emitting device is irradiated by removing the low frequency noise component of the grayscale fluctuation and the periodic high frequency noise component of the grayscale fluctuation. Since it is possible to eliminate the influence of disturbance such as unevenness and wire marks of wires, it is possible to properly analyze the quality of paper without being affected by the disturbance. Since the obtained analysis results are displayed on the display device in time series, the operator can easily grasp and evaluate the actual paper quality as a feeling from the analysis results, and provide appropriate feedback to the operation. You can

In particular, when the formation is monitored as the quality of the paper, the formation can be properly digitized, and the obtained formation index is displayed in time series on the display device.
The operator can easily grasp the actual formation as a feeling from the formation index. Therefore, according to the paper machine and the paper manufacturing method using the quality monitoring device as the formation monitoring device, the operator can easily grasp the formation as a feeling from the formation index displayed in time series on the display device. As a result, proper feedback to the parameter adjustment by the adjusting device is possible, and as a result, optimally texture-adjusted paper can be easily manufactured. Further, since the texture of the paper is estimated from the wet paper in the former part, the texture change with respect to the adjustment parameter can be grasped instantly, and the optimal texture can be quickly adjusted.

Further, a discharging device for discharging the wet paper from the traveling line is provided between the former portion and the inlet of the dryer portion, and the wet paper is discharged from the traveling line until the desired formation index is obtained. As a result, the spoiled paper discharged during the adjustment can be reused in the wet paper state. Therefore, the deterioration of pulp properties can be reduced and the pulp can be effectively reused as a high-quality raw material, and the paper can be efficiently produced.

Further, when the defect is monitored as the quality of the paper, it is possible to properly analyze the existence of the defective portion in the wet paper, and the analyzed position in the width direction of the defective portion is displayed on the display device in time series. Therefore, the operator can easily grasp the actual defect state as a sensation from the analysis result. Therefore, according to the paper machine and the paper manufacturing method using the quality monitoring device as the defect monitoring device, the operator is present on the wet paper by observing the widthwise position of the defective portion displayed in time series on the display device. Since it is possible to easily grasp the defects that occur as a sense,
It becomes easy to identify the location of the defect on the papermaking line, and it becomes possible to quickly manufacture a paper without any defect.

Further, a discharging device for discharging the wet paper from the traveling line is provided between the former portion and the dryer portion inlet, and the wet paper is discharged from the traveling line by the discharging device while the defective portion is displayed on the display device. By discharging, the spoiled paper discharged during the defect elimination can be reused in the wet paper state.
Therefore, the deterioration of pulp properties can be reduced and the pulp can be effectively reused as a high-quality raw material, and the paper can be efficiently produced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a quality monitoring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of attachment of a video camera and a strobe light emitting device of the quality monitoring device of FIG.

FIG. 3 is a diagram showing an example of mounting a video camera and a stroboscopic light emitting device of the quality monitoring device of FIG.

4A and 4B are diagrams showing examples of measures for preventing dirt on a video camera of the quality monitoring device of FIG. 1, in which FIG. 4A is a side view of the box, and FIG. 4B is a bottom view thereof.

5 is a diagram showing an example of arrangement of an image capturing unit of the quality monitoring device of FIG. 1 on a paper machine (single-layer paper making).

6 is a diagram showing an arrangement example of an image capturing unit of the quality monitoring device of FIG. 1 on a paper machine (four-layer paper making).

7 is a diagram showing an arrangement example of an image capturing unit of the quality monitoring device of FIG. 1 on a paper machine (two-layer paper making).

8 is a diagram showing a processing flow in the quality monitoring device of FIG.

9 is a diagram showing a flow of background light amount variation removal processing in the processing flow of FIG. 9;

FIG. 10 is a diagram showing a flow of periodic noise removal processing in the processing flow of FIG. 9;

11 is a diagram showing in detail the calculation flow after the averaging process in the process flow of FIG. 9;

FIG. 12 is a formation trend graph displayed on the display device of the quality monitoring device of FIG. 1.

13A and 13B are views for explaining a defect detection method by the quality monitoring device of FIG. 1, where FIG. 13A is a diagram showing an image of a normal wet paper sheet and its luminance value distribution, and FIG. 13B is a dark defect. FIG. 3 is a diagram showing an image of a wet paper sheet and its luminance value distribution, and FIG. 7C is a diagram showing an image of a wet paper sheet having a bright color defect and its luminance value distribution.

FIG. 14 is a defect trend graph displayed on the display device of the quality monitoring device of FIG.

FIG. 15 is a graph showing characteristics of parameters (J / W ratio) for formation adjustment.

FIG. 16 is a graph showing the characteristics of parameters (opposite dewatering blade linear pressure) for formation adjustment.

FIG. 17 is a block diagram showing a configuration of a general paper machine.

[Explanation of symbols]

1 Video Camera 2 Strobe 3 Camera Amplifier 4 Strobe Amplifier 6 Computer 6a Image Capture Board 6b Computer Main Body 6c Monitor 7 Dirt Prevention and Shading Box 7b Transparent Shield 8 Evacuation Arm 10 Wet Paper 11 Camera Scan Rope 12 Pulley 13 Fixed Rope 14 Hook 15 Strobe scan rail 16 Blow box 18 Frame 20, 21, 33, 36, 39, 42, 43, 52, 5
5 wire 22, 31, 34, 37, 40 head box 24, 25, 26, 27, 32, 35, 38, 41, 5
1,54 Dehydration equipment

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanobu Matsumoto             Hiroshima Prefecture Mihara City Itozakicho 5007 Mitsubishi Heavy Industries             Paper and printing machinery division F-term (reference) 4L055 CE90 DA25                 5C054 CB04 CD01 CF05 FC01 FC12                       FC16 HA05

Claims (29)

[Claims] 1. A video camera that captures a wet paper web running in contact with at least one wire as a static two-dimensional image; and a light-emitting device that is arranged opposite to the video camera with a running line of the wet paper webbing interposed therebetween. An image processing apparatus that processes an image captured by the video camera to remove at least one of a low-frequency noise component of grayscale fluctuation and a periodic high-frequency noise component of grayscale fluctuation; and A paper quality monitoring device comprising: a calculation device for analyzing the quality of the wet paper web from an image; and a display device for displaying a result of analysis of the quality of the wet paper web by the calculation device in time series. 2. The paper quality according to claim 1, wherein the image processing apparatus further performs an averaging process on the processed image according to a visual field range and a resolution of the video camera. Monitoring device. 3. The paper quality monitoring device according to claim 1, wherein the video camera is provided with a light shielding cover. 4. The paper quality monitoring device according to claim 1, wherein a dirt adhesion prevention cover is attached to at least one of the video camera and the light emitting device. . 5. A retracting means for retracting at least one of the video camera and the light emitting device from an image capturing position to a retracted position off the running line of the wet paper web is provided. The paper quality monitoring device according to any one of 1. 6. The paper quality monitoring device according to claim 5, further comprising a stain removing unit that removes stains attached to the video camera or the light emitting device at the retracted position. 7. The paper quality monitoring according to claim 1, wherein a plurality of sets of the video camera and the light emitting device are arranged in a width direction of the wet paper web. apparatus. 8. A video camera moving means for moving the video camera in the width direction of the wet paper web, wherein still two-dimensional images are captured by the video camera at a plurality of positions in the width direction of the wet paper web. To do
The paper quality monitoring device according to claim 1. 9. The light emitting device moving means for moving the light emitting device in the width direction of the wet paper web while synchronizing with the movement of the video camera by the video camera moving means. Paper quality monitoring device. 10. The paper according to claim 1, wherein at least one of the video camera and the light emitting device is embedded in a frame extending across the width of the wet paper web. Quality monitoring equipment. 11. The light emitting device is configured as a stroboscopic light emitting device which emits light intermittently in synchronization with capturing of an image by the video camera.
0. The paper quality monitoring device according to any one of 0. 12. The video camera according to claim 1, wherein the video camera is configured as a line camera, and the light emitting device is configured as a continuous light emitting device that continuously emits light. The described paper quality monitoring device. 13. The display device is configured to calculate a formation index indicating the superiority or inferiority of the formation of the wet paper web by statistically processing the density variation of the image processed by the image processing device. The paper quality monitoring device according to claim 1, wherein the formation index calculated by the calculation device is displayed in a time series. 14. The display device displays the formation index for each time series as a correlation graph with an adjustment parameter of a paper machine that correlates with the formation of the wet paper web. Paper quality monitoring device. 15. A paper machine provided with a former section for forming wet paper while dewatering a paper raw material liquid ejected from a headbox on a wire or between a pair of wires by one or more dewatering devices. The paper quality monitoring device described in 13 or 14, and the properties of the paper type and pulp chemicals, the concentration of the paper raw material liquid, the ejection speed of the head box, the traveling speed of the wire, the dehydration pressure of the dehydrator or the dehydrator. An adjusting device for adjusting at least one parameter among the pressing pressure of the constituent blades, and an image capturing unit including the video camera and the light emitting device is provided in the former section. , Paper machine. 16. The paper machine according to claim 15, wherein the image capturing unit is provided at a plurality of positions along the running line of the wet paper web. 17. The paper machine according to claim 15, further comprising a discharging device that discharges the wet paper from the traveling line between the former portion and the dryer inlet. 18. A method for producing paper using the paper machine according to claim 15 or 16, wherein the adjusting device is such that the formation index displayed on the display device during papermaking is a desired value. The paper manufacturing method is characterized in that the above-mentioned parameters are adjusted by the method described above, and papermaking is carried out with the parameter values at which a desired formation index is obtained. 19. A method for producing paper using the paper machine according to claim 17, wherein the adjusting device adjusts the formation index displayed on the display device during papermaking to a desired value. The wet paper is discharged from the running line by the discharging device until the desired formation index is obtained by adjusting the parameters, and when the desired formation index is obtained, the wet paper is returned to the running line. A method for producing paper, which comprises performing papermaking with a parameter value for obtaining a desired formation index. 20. The arithmetic unit is configured to filter an image processed by the image processing unit to analyze the presence of a defective portion in the wet paper, and the display unit is analyzed by the arithmetic unit. 13. The paper quality monitoring device according to claim 1, wherein the position in the width direction of the defect portion is configured to be displayed in time series. 21. The computing device is configured to identify a defect type of the defective portion, and the display device displays the position in the width direction of the defective portion together with the defect type. Paper quality monitoring device. 22. The computing device obtains a correspondence relationship between a widthwise position of the defective portion and a widthwise position of the defective portion detected by different parts of the paper machine in consideration of the amount of paper draw and shrinkage. The display device is characterized in that the width direction position of the defective portion is displayed so as to overlap with the width direction position of the defective portion detected in the other part. 20. The paper quality monitoring device according to 20 or 21. 23. The arithmetic unit is configured to estimate a defect occurrence point on a papermaking line based on a result of superimposing the plurality of defect portions, and the display device displays the estimated defect occurrence point. 23. The paper quality monitoring device according to claim 22, wherein: 24. The paper quality monitoring apparatus according to claim 20, further comprising sensitivity adjusting means for adjusting the detection sensitivity of the defective portion by the arithmetic unit. . 25. A paper machine provided with a former section for forming a wet paper while dewatering a paper raw material liquid ejected from a headbox on a wire or between a pair of wires by one or more dewatering devices. 20. A paper machine comprising the paper quality monitoring device according to any one of 20 to 24, wherein an image capturing unit including the video camera and the light emitting device is provided in the former section. 26. The paper machine according to claim 25, wherein the image capturing unit is provided at a plurality of positions along the running line of the wet paper web. 27. The paper machine according to claim 25 or 26, further comprising a discharge device for discharging the wet paper web from a traveling line between the former portion and the dryer entrance. 28. A method for producing paper using the paper machine according to claim 25 or 26, wherein a defect on a papermaking line is detected based on a position in a width direction of a defective portion displayed on the display device during papermaking. A method for producing paper, characterized in that an occurrence point is specified, and the specified defect occurrence point is adjusted to perform papermaking. 29. A method for producing paper using the paper machine according to claim 27, wherein the location of a defect on the papermaking line based on the widthwise position of the defective portion displayed on the display device during papermaking. Adjusting the defect occurrence point by specifying, while the defective portion is displayed on the display device, the wet paper is discharged from the traveling line by the discharging device, and when the defective portion is no longer displayed, the wet paper is removed. It is characterized by returning to the running line and making paper.
Paper manufacturing method.