JP3325117B2 - Paper fiber orientation measuring method and fiber orientation measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber orientation measuring method and a fiber orientation measuring apparatus suitable for measuring the fiber orientation characteristics of paper at rest or during a papermaking process.

[0002]

2. Description of the Related Art In order to produce high quality paper, it is necessary to measure the paper quality and fiber orientation characteristics of the produced paper. A conventional fiber orientation measuring apparatus of this type is disclosed in JP-A-4-57.
No. 983, a non-contact type orientation meter,
There is a fiber orientation measuring device described in JP-A-113205, etc., and these devices make use of the incidence and reflection of light on paper.

[0003] Although these conventional devices are suitable for measuring the fiber orientation characteristics of the cut sample, there is an inconvenience in measuring the fiber orientation characteristics of the web in the paper making process. For this reason, the present applicant has already proposed a fiber orientation measuring method and a fiber orientation measuring apparatus capable of measuring the fiber orientation characteristics of a web in a paper making process online (Japanese Patent Application No. 5-62581).
issue).

In this method for measuring the fiber orientation of paper, non-polarized light is radiated perpendicularly to the paper surface of a stationary or running paper, and the paper is irradiated with a surface parallel to the paper surface on the incident side of the detection light on the paper surface. At eight or more locations on the circumference in the parallel plane centered on the intersection with the optical axis, the light reflected by the paper surface is captured almost simultaneously, and the fiber orientation index, fiber orientation angle, etc. are obtained from the intensity of the reflected light. Is characterized by calculating the fiber orientation characteristics of, the fiber orientation measuring device that has realized this method, the projection means for irradiating non-polarized light perpendicular to the paper surface of the stationary or running paper, It is arranged on the circumference of the detection light on the incident side of the detection light and on the circumference in the parallel plane centered on the intersection of the plane parallel to the paper plane and the incident optical axis, and the light receiving unit is located between the paper plane and the incident optical axis. Eight or more light receiving means for capturing light reflected by the paper surface facing the intersection, An optical information processing circuit for receiving the reflected light intensity measured by each light receiving means, appropriately processing the input signal and outputting light intensity information, and a fiber orientation index from the output signal of the optical information processing circuit. And an arithmetic circuit for calculating a fiber orientation angle and the like.

[0005]

Generally, the fiber orientation of paper produced by a paper machine such as a fourdrinier type is almost determined by a wire part. In addition, if the papermaking conditions such as the supply state of the raw material to the wire part and the operation state of the wire part are constant, the fiber orientation shows a substantially constant value in the paper flow direction (machine direction). Therefore, when trying to measure the fiber orientation of paper on a paper machine, the fiber orientation in the paper flow direction is almost constant, so the running paper web moves and the light intensity reflected from the measurement point on the shifted paper surface Is measured, the fiber orientation can be calculated. When the measurement is performed by such a method, it is not necessary to simultaneously measure the reflected light intensity of the same portion of the running paper web. That is, a plurality of light receiving means is not required unlike the fiber orientation measuring apparatus which has already been applied by the present applicant.

However, in order to grasp the fiber orientation characteristics,
It is necessary to measure fiber orientation for 360 °.

In view of the fact that it is not necessary to precisely measure the fiber orientation of the same portion of a paper web running on a paper machine at the same time, the present invention requires a single light receiving means. It is a main object of the present invention to provide a method and an apparatus for measuring the fiber orientation of paper, which can detect the fiber orientation characteristics of each animal.

[0008]

SUMMARY OF THE INVENTION As a technical means for achieving the above-mentioned main object, a method for measuring the fiber orientation of paper according to the present invention is described. And irradiates a detection light consisting of at least 8 on a circumference in a plane parallel to the plane of paper on the incident side of the detection light, the intersection of the plane parallel to the plane of paper and the incident optical axis.
Of the light reflected by the paper surface at
Sequentially captures polarized light vibrating in a direction parallel to, supplemental
It is characterized in that to calculate the fiber orientation characteristics such as fiber orientation index or fiber orientation from the intensity of the reflected light.

[0009] Further, for a stationary or running paper surface,
Irradiates the detection light composed of unpolarized light vertically,
The plane parallel to the paper on the incident side of the detection light and the incident optical axis
At least on the circumference in the parallel plane centered at the intersection of
Light reflected by the paper at eight locations
Polarized light oscillating in the direction perpendicular to the plane is sequentially captured and compensated.
Fiber orientation index or fiber orientation from the added reflected light intensity
It is characterized by calculating fiber orientation characteristics such as angles.
You.

Furthermore, by taking out reflected light reflecting the fiber orientation from the light reflected by the paper fibers at the time of measurement and processing the data with this reflected light, it is possible to grasp the orientation characteristics as accurately as possible. Then, using linearly polarized light instead of unpolarized light as the detection light, irradiate the detection light composed of linearly polarized light perpendicularly to the paper surface of the stationary or running paper, and change the oscillation direction of the linearly polarized light to the incident light. Pivoted about an axis, and at least eight points on the circumference of the plane parallel to the plane of the drawing on the incident side of the detection light on the incident side of the plane of the drawing and the incident optical axis. The light reflected by the paper is transmitted through a polarizer that separates linearly polarized light oscillating in the same direction as the oscillation direction of the linearly polarized light to sequentially capture the linearly polarized light, and the distribution of the intensity of the reflected light is approximated by a curve. Before
It is characterized by determining a fiber <br/>維配direction angle for to contribute to the evaluation of the fiber orientation characteristics of serial paper.

The linearly polarized light that reflects well on the surface of the fiber and reduces the light incident on the paper layer as much as possible is the polarized light that vibrates in the direction perpendicular to the incident / reflective surface. When linearly polarized light is used, the linearly polarized light that is the detection light is polarized light that vibrates in a direction perpendicular to the incident / reflective surface.

In order to more accurately grasp the fiber orientation characteristics when irradiating either unpolarized light or linearly polarized light, the light reflected by the paper surface is captured by a plane parallel to the paper surface and incident light. It is characterized in that it is carried out at positions at substantially equal intervals on the circumference around the intersection with the axis.

The fiber orientation measuring apparatus suitable for carrying out the paper fiber orientation measuring method according to the present invention includes:
A light projecting unit that irradiates a non-polarized detection light perpendicularly to the paper surface of the stationary or running paper, and is disposed on the non-polarized light incident side of the paper surface, and pivots around the incident optical axis, A light-receiving unit facing at the intersection of the paper surface and the incident optical axis and capturing at least one light-receiving unit that reflects the light reflected by the paper surface; and the reflected light intensity measured by the light-receiving unit is input. An optical information processing circuit that appropriately processes and outputs light intensity information, and an output signal of the optical information processing circuit contributes to evaluation of fiber orientation characteristics of the paper.
And an arithmetic circuit for determining a fiber orientation angle, wherein the light received by the light receiving means sequentially captures light reflected by the paper surface at least at eight points on the turning trajectory during the turning of the light receiving means.

A light projecting means for irradiating a non-polarized detection light perpendicularly to the paper surface of the stationary or running paper;
An annular reflecting mirror for reflecting reflected light emitted from the light projecting unit and reflected on the paper surface in a direction passing through a fixed point on an incident optical axis; and reflecting the reflected light from the annular reflecting mirror in the direction of the incident optical axis. A measuring light reflecting mirror that rotates about the optical axis; a light receiving unit that captures light reflected by the measuring light reflecting mirror; and a reflected light intensity measured by the light receiving unit. An optical information processing circuit that appropriately processes a signal to output light intensity information; and an output signal of the optical information processing circuit contributes to evaluation of fiber orientation characteristics in the paper.
And an arithmetic circuit for calculating the fiber orientation angle for causing
During one rotation of the measuring light reflecting mirror, the light reflected by the paper surface is sequentially captured by the light receiving means for at least eight places of the annular reflecting mirror.

Further, when irradiating with non-polarized light,
The light receiving means for capturing and measuring is provided with a polarizer for separating polarized light oscillating from reflected light in one of a direction parallel or perpendicular to an incident / reflective surface.

Further, in order to provide a fiber orientation measuring apparatus using linearly polarized light as the detection light, the linearly polarized detection light is irradiated perpendicularly to the paper surface of the stationary or running paper and rotated about the optical axis. And a light projecting means, which is arranged on the incident side of the linearly polarized light on the plane of the paper, rotates around the incident optical axis in synchronization with the rotation of the light projecting means, and the light receiving unit is positioned between the plane of the paper and the incident optical axis. At least one light receiving unit that captures the linearly polarized light by passing through a polarizer that separates linearly polarized light that oscillates in a direction equal to the oscillation direction of the linearly polarized light and that reflects the light reflected by the paper surface facing the intersection; An optical information processing circuit that receives the reflected light intensity measured by the means, processes the input signal as appropriate, and outputs light intensity information ;
Calculate fiber orientation angle to contribute to evaluation of fiber orientation characteristics
The light receiving means sequentially captures light reflected by the paper at at least eight locations on the turning trajectory during the turning of the light receiving means.

[0017] In addition to irradiating detection light composed of linearly polarized light perpendicularly to the paper surface of the stationary or running paper,
A light projecting unit that rotates about the optical axis, an annular reflecting mirror that reflects reflected light emitted from the projecting unit and reflected on the paper surface in a direction passing through a fixed point on the incident optical axis, and reflected by the annular reflecting mirror Reflecting the reflected light in the direction of the incident optical axis, the measuring light reflecting mirror that rotates in synchronization with the rotation of the light projecting means about the optical axis, and the reflected light reflected by the measuring light reflecting mirror, A light-receiving unit that transmits a polarizer that rotates in synchronization with the light-projecting unit corresponding to the linearly-polarized light and captures the linearly-polarized light, and a reflected light intensity measured by the light-receiving unit are input, and the input signal is appropriately converted. An optical information processing circuit that outputs light intensity information by processing the optical information processing circuit; and an output signal of the optical information processing circuit contributes to evaluation of fiber orientation characteristics in the paper.
And an arithmetic circuit for determining a fiber orientation angle for the light. The light reflected by the paper surface at least at eight positions of the annular reflecting mirror during one rotation of the light projecting means and the polarizer is received by the light receiving means. It is characterized by capturing sequentially.

Further, the linearly polarized light which is the detection light is a polarized light which oscillates in a direction perpendicular to the incident / reflective surface, or is at a position where the orbit of the light receiving means or the annular reflecting mirror is divided at substantially equal intervals. The reflected light is captured by the light receiving means.

[0019]

The detecting means irradiates the detection light from the direction perpendicular to the paper surface with the reflected light, and applies the reflected light to the center of the intersection of the incident light axis with the surface parallel to the paper surface on the incident side of the detection light on the paper surface. Since the light is captured at at least eight locations on the circumference in a parallel plane, the angles formed by the incident optical axis and the reflected optical axis are equal for all measurement positions.

When the paper to be detected is stationary, the fiber orientation can be measured within the range of 360 ° with respect to the same portion of the paper surface. Therefore, the variation in the intensity of the reflected light captured at each position depends on the orientation of the paper surface. It will show a tendency according to the characteristics. For this reason, orientation characteristics such as a fiber orientation index and a fiber orientation angle are required from the variation in the intensity of the reflected light.

When the paper to be detected is running on a paper machine or the like, it is not possible to measure the reflected light intensity with respect to the same portion of the paper web. However, since the fiber orientation of the web running on the paper machine is substantially constant, the reflected light intensity will be substantially equal when the measuring angles of the light receiving means are equal. Therefore, by constantly measuring the intensity of the reflected light, the tendency of the orientation characteristics of the paper web can be obtained. If the tendency deviates from this tendency, it can be determined that the predetermined paper quality is not maintained.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus for measuring the fiber orientation of paper according to the present invention will be specifically described below with reference to the illustrated embodiments.

FIG. 2 is a front view schematically showing the fiber orientation measuring apparatus, in which a light projecting means 10 is disposed above the paper surface 1a of the paper 1 whose fiber orientation characteristics are to be measured. The light projecting means 10 includes a semiconductor laser 11, a lens 12, a polarizer 13, and a quarter wave plate 14.
The laser light emitted by the semiconductor laser 11 is transmitted through the lens 12, the polarizer 13, and the quarter-wave plate 14 to obtain circularly polarized light Li. Circularly polarized light is light that travels while rotating its polarization direction and is different from non-polarized light that has no polarization characteristics, but is regarded as non-polarized light because the rotation period of the polarization direction is extremely short, about 10 ^-15 seconds. be able to. Of course, a light emitting means having a halogen lamp or the like emitting non-polarized light and an optical system for converting non-polarized light into parallel light may be used. The light projecting means 10 is arranged at a position where the circularly polarized light Li is irradiated onto the paper surface 1a in a vertical direction.

On the other hand, as shown in FIGS. 1 and 2, the light receiving means 20 comprises a polarizer 21 and a light receiving element 22 for converting light intensity into an electric signal. And this light receiving means 20
Is provided so that the light receiving portion turns around the incident optical axis while maintaining the state where the light receiving section faces the intersection of the incident optical axis of the circularly polarized light Li and the paper surface 1a. Therefore, the laser light emitted from the light emitting means 10 is reflected on the paper surface 1a,
The reflected light Lr is captured by the light receiving means 20.

The reflected light Lr captured by the light receiving means 20
Is transmitted through the polarizer 21 to be separated into predetermined polarized light, and then enters the light receiving element 22. At this time, the incident and reflected light angle θr between the circularly polarized light Li and the reflected light Lr is 0.
Although it is in the range of ° <θr <90 °, in order to calculate the fiber orientation, it is desirable that the reflectance of light reflecting the fiber orientation is higher, and for that purpose, it is desirable to increase the incident / reflection angle θr.

FIG. 7 is a schematic perspective view for explaining an embodiment of a mechanism for rotating the light receiving means 20 around an incident optical axis. The light receiving means 20 is accommodated in a through hole 23a formed in a part of the rotatable gear 23, and is fixed in a state where the light receiving part faces the intersection between the incident optical axis of the circularly polarized light Li and the paper surface 1a. Have been. A pinion 24 meshes with the gear 23, and power is transmitted to the pinion 24 from a drive device (not shown) to rotate the gear 23. This gear
The light projecting means 10 is disposed above the light source 23, and the incident optical axis of the light projecting means 10 and the rotation center axis of the gear 23 are aligned. The boss 23b of the gear 23 is hollow, and
From 10, the circularly polarized light Li is irradiated on the paper surface 1 a through the hollow portion.

The mechanism for turning the light receiving means 20 with its light receiving portion facing the intersection of the incident optical axis and the paper surface 1a is as follows.
A mechanism using a planetary gear device or a link device other than the mechanism shown in FIG. 7 may be used.

An encoder (not shown) for detecting the rotation angle of the gear 23 is provided to detect that the gear 23 has rotated a predetermined angle. This encoder is preferably of a non-contact type such as an optical type. The output signal of the encoder detects, for example, a state in which the gear 23 is rotated by 45 °, and when the detection signal is output, the light receiving means 20 sequentially captures the reflected light Lr. During one revolution, the reflected light Lr can be captured at a position where the revolution trajectory is divided into eight equal parts.
If the speed ratio between the gear 23 and the pinion 24 is 1/8 and an encoder is provided in the pinion 24, the rotation path of the light receiving means 20 is divided into eight equal parts for each rotation of the pinion 24. The reflected light Lr can be captured.

Further, if the capturing position of the reflected light Lr by the light receiving means 20 is locally densely arranged on the above-mentioned orbit, data in a direction in which the paper surface 1a is deviated is collected, and accurate fiber orientation characteristics are obtained. Can not be obtained. Therefore, it is desirable that the light receiving means 20 be captured at substantially equal intervals on the turning trajectory. In the case where the fiber orientation of the paper web can be estimated to be substantially along the flow direction of the paper paper, as in the case of measuring the orientation characteristics of the paper web on the paper machine, the reflected light Lr is captured. It is acceptable to capture at an easy position.

Further, the polarizer 21 of the light receiving means 20 separates the polarized light oscillating in the direction perpendicular to the incident / reflective surface including the incident light Li and the reflected light Lr from the reflected light Lr, or It separates polarized light that vibrates in a direction parallel to the incident / reflective surface. Therefore, the light receiving element 22 captures only the polarized light that oscillates in the vertical direction or the polarized light that oscillates in the parallel direction according to the disposed polarizer 21. Note that the reflected light Lr is received by the light receiving element without separating the polarized light without using the polarizer 21.
It may be something that is captured in 22. Since the reflectance of the light reflecting the fiber orientation becomes the highest in the polarized light oscillating in the direction perpendicular to the incident / reflective surface, the intensity of the reflected light Lr is determined by using the polarizer 21 for separating the polarized light. It is desirable to measure

In the embodiment shown in FIG. 7, a structure in which one light receiving means 20 is provided has been described, but two or more light receiving means 20 may be provided. Then, for example, two light receiving means 20
If they are used, place them in a 180 ° relationship. In the case of three, an interval of 120 ° is provided for each. It should be noted that if the number of the light receiving means 20 increases, the measurement accuracy can be improved.

As shown in FIG. 5, the output terminal of the light receiving element 22 is connected to the input terminal 31a of the optical information processing circuit 31, and the intensity of the reflected light Lr captured by the light receiving element 22 is an electric signal. And is input to the optical information processing circuit 31. The optical information processing circuit 31 appropriately processes the input light intensity signal to obtain the reflected light L captured by the light receiving element 22.
The optical information signal includes the intensity F of r and the measured position angle θ of the light receiving element 22 on the turning trajectory of the light receiving means 20. An arithmetic circuit 32 is connected to the output side of the optical information processing circuit 31, and the arithmetic circuit 32 converts the input optical information signal into

By applying to F (θ) = C (1 + ηCOS2 (θ−α)), an orientation index η representing the strength of the fiber orientation on the paper 1a and an orientation angle α representing the direction of the fiber orientation on the paper 1a. Is calculated. In Equation 1, F represents light intensity, and θ represents light receiving means.
20 measurement position angles and C represents the average value of the reflected light intensity. Equation 1 is a part of the Fourier series and is known as a periodic function that approximates the fiber orientation of the paper from the collected data. In addition to this equation, von Meis (Von Mises) function, elliptic function, etc. can also be used.

The orientation index η and orientation angle α calculated by the arithmetic circuit 32 are displayed on display means 33 such as a CRT display device connected to the arithmetic circuit 32,
It is printed by a printer or plotter connected to 32.

FIG. 8 schematically illustrates a fiber orientation measuring apparatus according to another embodiment in which one light receiving means 20 performs measurement at a measuring angle of 360 ° when measuring the reflected light intensity on the paper surface. FIG. An annular reflecting mirror 25 having a reflecting mirror portion 25a formed on the inner surface is provided below the light projecting means 10. The circularly polarized light Li emitted from the light projecting means 10 is
1a, and the reflected light Lr is reflected by the reflecting mirror portion 25 of the annular reflecting mirror 25.
The light is reflected at a and passes through a point above the light projecting means 10 and on the incident optical axis. Then, the measurement light reflecting mirror 26 is rotatably provided around the optical axis at the passing point on the optical axis.
The light reflected by the annular reflecting mirror 25 and incident on the passing point is reflected upward along the optical axis. Above the measuring light reflecting mirror 26, a light receiving means 20 including a polarizer 21 and a light receiving element 22 is provided so as to capture light reflected by the measuring light reflecting mirror 26. And
Each time the measurement light reflecting mirror 26 rotates by a predetermined angle, the reflected light is captured by the light receiving means 20. For example, if the reflected light is captured every time the measuring light reflecting mirror 26 rotates 45 °, 360 ° can be set to 8 at a predetermined point on the paper surface 1a.
Fiber orientation can be measured at equally divided angular positions.

Further, the embodiment shown in FIG.
There between the position of the d ₀ of a ₀ shown in phantom, which has been described for the case of reciprocating motion along the arc centered on the axis of incidence light, and corresponds to FIG 1. The same parts as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In general, when the light intensity of reflected light is measured on paper manufactured by a paper machine such as a fourdrinier type, as shown in FIG. 4, the reflected light intensity from the paper surface 1a is expressed as a periodic function of the period π. By measuring in the range, the fiber orientation characteristics of the paper can be determined. That is, since the fiber orientation characteristics of the web are related to the light intensity, the fiber orientation characteristics of the web can be substantially determined from the result obtained by measuring the period. For this reason, in this embodiment, the light receiving means 20 is reciprocated, and the paper
It shows a device for measuring the reflected light from 1a. When the measurement position angle θ at the measurement position a ₀ is 0 °, the light intensity at the measurement position at the measurement position angle θ of 180 ° can be estimated from the data at the measurement position a _0. It is not necessary to collect Therefore,
180 to capture reflected light at four locations within a 180 ° range
The reflected light is captured at 45 ° intervals obtained by dividing the angle into four equal parts. That is, the light receiving means 20 is reciprocated within a range of 135 °, and the reflected light is captured every 45 ° during the movement. Then, the collected reflected light intensity is data at the measurement position angle θ of a ₀ , b ₀ , c ₀ , and d ₀ in FIG.
By shifting by 180 °, the data of a ₁ , b ₁ , c ₁ , and d ₁ can be estimated in FIG.

In order to reciprocate the light receiving means 20 on an arc, for example, in the mechanism shown in FIG. 7, a reversible rotating motor is used as a motor of a driving device for driving the pinion 24.
What is necessary is just to make it reverse at a rotation angle of 135 degrees.

In the above-described embodiment, the detection light emitted from the light projecting means 10 has been described as non-polarized light (circularly polarized light). There is linear polarization that is easy to process,
Further, linearly polarized light that best reflects the fiber orientation of the paper is polarized light that vibrates in a direction perpendicular to the incident / reflective surface. Therefore, polarized light oscillating in the direction perpendicular to the incident / reflective surface from the light projecting means 10 is irradiated from the perpendicular direction toward the paper surface 1a, and polarized light oscillating in the direction perpendicular to the incident / reflective surface is separated from the reflected light. By capturing the reflected light, the reflected light that best reflects the fiber orientation can be captured, and the reflected light that contributes to the fiber orientation can be reliably captured.

When linearly polarized light is used as detection light, FIG.
As shown in FIG. 2, the quarter wave plate 14 of the light projecting means 10 shown in FIG.
Next, a polarizer 15 is provided so that the light transmitted through the quarter-wave plate is further transmitted through the polarizer 15. As the polarizer 21 of the light receiving means 20, one that transmits linearly polarized light that oscillates in the same direction as the oscillation direction of the linearly polarized light emitted from the light projecting means 10 is used.

In order for one light receiving means 20 to capture reflected light at a plurality of locations on the circumference, the light receiving means 20
Is rotated about the incident optical axis. Incidentally, since linearly polarized light is emitted from the light projecting means 10, the linearly polarized light must oscillate in a predetermined direction with respect to the incident / reflective surface. For this reason, it is necessary to rotate the light projecting means 10 about the optical axis and synchronize the turning of the light receiving means 20 with the rotation of the light projecting means 10.

When the mechanism shown in FIG. 7 is used, if the light emitting means 10 is fixed to the boss 23b of the gear 23, the light emitting means 10 and the light receiving means 20 can be synchronized. . In the mechanism shown in FIG. 8, the rotation of the light projecting means 10 and the rotation of the measurement reflecting mirror 26 are synchronized, and the polarizer 21 is rotated in synchronization with them.

Also, when irradiating linearly polarized light, reflected light is captured at at least eight places on the orbit of the light receiving means 20.

When irradiating linearly polarized light from the light projecting means 10, reflected light can be captured while the light receiving means 20 reciprocates along an arc centered on the incident optical axis.
In this case, the light projecting means 10 is rotated at a predetermined angle, and the light receiving means 20 is reciprocated in synchronization with the rotation.

The operation of the fiber orientation measuring method and the fiber orientation measuring apparatus according to the present invention constituted as described above will be described below.

In the embodiment shown in FIG. 7, when power is transmitted from a drive unit (not shown) to the pinion 24, the pinion 24
And the gear 23 meshing therewith rotate. This gear 23
, The light receiving means 20 is fixed, so that the rotation of the gear 23 causes the light receiving means 20 to turn. Gear 23
Rotates around the incident optical axis, the light receiving means 20 also turns around the incident optical axis. Moreover, the light receiving means
Since the light receiving unit 20 turns while facing the intersection of the paper surface 1a of the paper 1 whose fiber orientation is to be measured and the incident optical axis, the reflected light Lr reflected on the paper surface 1a is captured by the light receiving means 20. Then, the reflected light Lr is captured at an appropriate position while the light receiving means 20 is turning.

The capture of the reflected light Lr is performed, for example, by receiving an output signal of an encoder (not shown) for detecting the rotation angle of the gear 23. Also, the capture of the reflected light Lr
It is preferable that the detection is performed at least at eight positions of the turning trajectory of the light receiving means 20, and that the light receiving unit 20 is captured at a position where the turning trajectory is equally divided into eight. When the reflected light Lr is captured at the position where the turning trajectory is equally divided into eight, a ₀ , b ₀ , c ₀ , d ₀ , a shown in FIG.
_1, b _1, c _1, reflected light data of d ₁ is to be taken. When the reflected light Lr is captured by the light receiving element 22, it is photoelectrically converted and input to the optical information processing circuit 31, where the light intensity signal is appropriately processed and transmitted to the arithmetic circuit 32. In the operation circuit 32, the operation according to the above equation 1 is executed, and the fiber orientation index η
And the orientation angle α are calculated.

The number of measurement positions is not limited to eight, and may be more than eight. If the angle position at which the reflected light Lr is captured and the reflected light intensity are detected, capture is performed continuously during turning. It may be something like that. That is,
As the number of capture positions increases, the accuracy of the measured fiber orientation characteristics improves.

In order to measure the orientation characteristics of a sample (paper) cut into one oval, the sample is fixed on a sample table and the light receiving means 20 is rotated once to rotate the sample at 360 ° with respect to a predetermined point of the sample.
If the data relating to the reflected light intensity is collected in the range described above and the sample table or the fiber orientation measuring device is moved and data is sequentially collected at a predetermined point on the sample, the two-dimensional fiber orientation distribution of the sample can be measured. Further, if the measurement is performed on the front and back of the sample, the fiber orientation distribution on the wire surface and the felt surface of the sample can be measured, and the fiber orientation distribution on the front and back of the sample can be measured.

In order to measure the fiber orientation characteristics of the paper web during the paper making process, a support is provided on both sides in the width direction of the paper machine, and a guide rail is stretched over the support, and the fiber orientation measuring device is used. What is necessary is just to install it on a paper machine, being guided by a guide rail so as to be movable. And
By scanning the fiber orientation measuring device in the cross machine direction along the guide rail, the fiber orientation characteristics of the web in the machine direction and the cross machine direction can be measured. In this case, because the paper web is moving, it is not possible to measure at one point on the paper surface at 360 °. However, since the fiber orientation on the paper machine should be in a certain direction, the same fiber orientation should be obtained at the same position in the width direction of the paper machine. Is obtained. That is, if data deviating from the fiber orientation data is obtained, the quality of the paper being manufactured will be different from the predetermined quality. Furthermore, if this apparatus is installed on the wire side and the felt side of the paper web during the paper making process and is scanned in the cross machine direction, the front-back difference of the fiber orientation characteristics in the machine direction and the cross machine direction can be measured. . When scanning is not performed, the fiber orientation characteristics of the paper web with respect to the machine direction can be measured.

As shown in FIG. 3, when the light receiving means 20 is reciprocated within a predetermined angle range around the incident optical axis, the reflected light Lr is reflected at an appropriate position during the reciprocating movement. Capture. Then, as described above, if the reflected light Lr is captured within the range of 180 °, the fiber orientation characteristics over 360 ° can be estimated from the data. In addition, if the measurement points correspond to the collection of eight data points at equal intervals while the light receiving means 20 makes one turn in the above-described embodiment, four measurement positions at equal intervals between 180 ° To collect data. That is, the light receiving means 20 is set to 1
A reciprocating motion in a range of 35 ° may be performed, and data may be collected every 45 °. Note that the measurement accuracy can be improved by increasing the number of measurement positions, but the angle range in which the light receiving means 20 reciprocates increases.

Further, the linearly polarized light from the light projecting means 10 is
Even when the light is irradiated, the light emitting means 10 is rotated or rotated within a predetermined angle range, and the light receiving means 20 is rotated or reciprocated along an arc to rotate or rotate the light emitting means 10. , The light receiving means 20 can always capture a predetermined linearly polarized light. In addition, by using polarized light that oscillates in a direction perpendicular to the incident / reflective surface as the linearly polarized light, the measurement processing can be performed with reflected light that most reflects the fiber orientation.

Further, even with a device for irradiating linearly polarized light, the fiber orientation characteristics of each of the felt surface and the wire surface of the paper 1 can be measured. Further, the fiber orientation can be measured with sufficient accuracy for a web running on a paper machine.

Next, the embodiment shown in FIG. 9 will be described. FIG. 9 is a schematic front view corresponding to FIG. 2, and the same portions as those in the above-described embodiment are denoted by the same reference numerals and description thereof will be omitted. .
At the position where the light receiving unit 20 is provided, a polarizer 21 and a reflected light input unit 41 are provided as a light receiving unit. An optical fiber 42 is connected to the reflected light input section 41, and a light receiving element (not shown) is connected to the output side of the optical fiber 42, and light transmitted through the optical fiber 42 enters the light receiving element. I have to do it.

The light reflected on the sheet 1a is a polarizer.
The transmitted light 21 is separated into polarized light that oscillates in a direction perpendicular or parallel to a plane including the incident optical axis Li and the reflected optical axis Lr, and is incident on the reflected light incident part 41. Then, the light passes through the optical fiber 42, enters a light-receiving element (not shown), is subjected to photoelectric conversion, and is subjected to an optical information processing circuit in the same manner as described above.
The orientation index η and orientation angle α are input to the arithmetic circuit 32.
Is calculated.

In the embodiment shown in FIG. 10, an optical fiber 42 is connected to the reflected light input section 41, and the output section of the optical fiber 42 is connected to the optical fiber 42.
43 faces the polarizer 21 so that the linearly polarized light transmitted through the polarizer 21 enters the light receiving element 22. FIG. 10 is also a schematic front view corresponding to FIG. 2, and the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof will be omitted. In this structure, the polarization characteristic of the light reflected on the paper surface 1a needs to be preserved up to the output unit 43. Therefore, the optical fiber 42 has a single polarization plane preservation mode.

Therefore, the reflected light reflected on the paper surface 1a enters from the reflected light input unit 41 and passes through the optical fiber 42 while maintaining the polarization characteristics. The reflected light emitted from the output unit 43 passes through the polarizer 21 and is separated into polarized light oscillating in a direction perpendicular to or parallel to a plane including the incident optical axis Li and the reflected optical axis Lr. And
The separated polarized light is captured by the light receiving element 22. Then
Photoelectric conversion is performed by the light receiving element 22 and input to the optical information processing circuit 31 in the same manner as described above, and the arithmetic circuit 32 calculates the orientation index η and the orientation angle α.

In the configuration using the optical fiber 42, only the input end of the optical fiber 42 is provided at the portion of the fiber orientation measuring device installed near the paper 1, so that The parts are reduced in size and weight. For this reason, when performing on-line measurement by scanning in the cross-machine direction, it is possible to reduce the space for installing the relevant portion and reduce the power for driving the apparatus in the cross-machine direction.

Although the embodiment shown in FIG. 9 has been described with respect to the configuration using an optical fiber for the light receiving means 20,
It is also possible to adopt a configuration using an optical fiber for 10, or a configuration using an optical fiber for both the light projecting means 10 and the light receiving means 20, and it is possible to further reduce the size and weight of the above parts.

[0058]

As described above, according to the method and apparatus for measuring the fiber orientation of paper according to the present invention, the fiber orientation characteristics of the paper can be measured by at least one light receiving means. The size and weight of the fiber orientation measuring device can be reduced.

Also, since linearly polarized light is applied to the paper surface of the paper whose fiber orientation characteristics are to be measured, linear polarized light corresponding to the linearly polarized light among the reflected light from the paper surface is captured. The data can be collected by the polarization that contributes to the measurement of. In addition, by using the linearly polarized light as a polarized light that oscillates in a direction perpendicular to the incident / reflective surface, data can be collected using reflected light that best reflects the fiber orientation.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic structure of a measuring unit in one embodiment of a fiber orientation measuring device according to the present invention.

FIG. 2 is a diagram showing a schematic structure of a measuring unit of the paper fiber orientation measuring apparatus according to the present invention, and is a schematic front view of FIG. 1;

FIG. 3 is a plan view showing a schematic structure of a measuring section in another embodiment of the fiber orientation measuring apparatus according to the present invention.

FIG. 4 is a graph for explaining characteristics of light intensity on the surface of a general paper.

FIG. 5 is a schematic circuit block diagram showing a configuration for arithmetically processing an optical information signal of the fiber orientation measuring apparatus according to the present invention.

FIG. 6 is a schematic front view corresponding to FIG. 2, showing a schematic structure of a measuring unit according to another embodiment of the paper fiber orientation measuring apparatus according to the present invention.

FIG. 7 is a schematic perspective view for explaining one embodiment of the mechanism of the fiber orientation device according to the present invention.

FIG. 8 is a schematic perspective view for explaining another embodiment of the mechanism of the fiber orientation device according to the present invention.

FIG. 9 is a diagram for explaining another embodiment of the fiber orientation measuring device according to the present invention, and is a schematic front view corresponding to FIG. 2;

FIG. 10 is a view for explaining still another embodiment of the fiber orientation measuring apparatus according to the present invention, and is a schematic front view corresponding to FIG. 2;

[Explanation of symbols]

 1 Paper 1a Paper surface 10 Light emitting means 11 Semiconductor laser 12 Lens 13 Polarizer 14 Quarter wave plate 15 Polarizer 20 Light receiving means 21 Polarizer 22 Light receiving element 23 Gear 24 Pinion 25 Ring reflector 26 Measurement light reflector 31 Optical information Processing circuit 32 Arithmetic circuit 33 Display means 41 Reflected light input section 42 Optical fiber Li Incident light Lr Reflected light θr Incident reflected light angle

Continuation of the front page (72) Inventor Akio Hatano 5-21-1, Oji, Kita-ku, Tokyo Nippon Paper Industries Central Research Laboratory (56) References US Patent 3,807,868 (US, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) D21F 7/00 D21F 7/06 G01B 11/26 G01N 21/89

Claims (12)

(57) [Claims] A non-polarized detection light is irradiated perpendicularly to a paper surface of a stationary or running paper, and a surface parallel to the paper surface on the incident side of the detection light on the paper surface and an incident optical axis. Light reflected by the paper surface at least at eight places on the circumference in the parallel plane centered at the intersection of
Paper and calculates the fiber orientation characteristics such as the direction parallel polarized light vibrating sequentially captured, the fiber orientation index or fiber orientation from the intensity of supplemented the reflected light with respect to incident reflection surface of the Fiber orientation measurement method. 2. The apparatus according to claim 1, wherein the paper is stationary or running.
Directly irradiate unpolarized detection light, A plane parallel to the plane of the drawing, on the side of the detection plane where the detection light is incident.
On the circumference in the parallel plane centered on the intersection of
Light reflected by the paper at least at eight places
Of the polarized light that vibrates in the direction perpendicular to the
To capture From the supplemented intensity of the reflected light, the fiber orientation index and fiber distribution
Paper characterized by calculating fiber orientation characteristics such as direction angle
Fiber orientation measurement method. 3. A method of irradiating detection light composed of linearly polarized light perpendicularly to a paper surface of a stationary or running paper, and rotating a vibration direction of the linearly polarized light about an incident optical axis. Vibration of the linearly polarized light reflects light reflected by the paper surface at at least eight locations on the circumference in the parallel surface centered on the intersection of a plane parallel to the paper surface and the incident optical axis on the detection light incident side. Transmitting a polarizer that separates linearly polarized light oscillating in the same direction as the direction and sequentially capturing the linearly polarized light, and calculating fiber orientation characteristics such as a fiber orientation index and a fiber orientation angle from the intensity of the reflected light. Characteristic paper fiber orientation measurement method. 4. The method according to claim 3, wherein the linearly polarized light as the detection light is a polarized light that vibrates in a direction perpendicular to the incident / reflective surface. 5. The method according to claim 1, wherein the light reflected by the paper surface is captured at positions at substantially equal intervals on the circumference around an intersection of a plane parallel to the paper surface and an incident optical axis. The method for measuring the fiber orientation of paper according to any one of claims 1 to 4. 6. A light projecting means for irradiating a non-polarized detection light perpendicularly to a paper surface of a stationary or running paper, and being arranged on the non-polarized light incident side of the paper surface and centering on an incident optical axis. And at least one light receiving unit in which the light receiving unit faces the intersection of the paper surface and the incident optical axis and captures light reflected by the paper surface, and the reflected light intensity measured by the light receiving unit is input. ,
An optical information processing circuit that appropriately processes the input signal to output light intensity information; and an arithmetic circuit that calculates a fiber orientation index, a fiber orientation angle, and the like from an output signal of the optical information processing circuit, The paper fiber orientation measuring device according to claim 1, wherein the light reflected by the paper surface is sequentially captured at least at eight points on the turning orbit while the light receiving means is turning. 7. A light projecting means for irradiating a non-polarized detection light perpendicularly to a paper surface of a stationary or running paper, and a reflected light emitted from the light projecting means and reflected on the paper surface on an incident optical axis. An annular reflecting mirror that reflects in a direction passing through the fixed point of, a reflecting light reflected by the annular reflecting mirror in a direction of the incident optical axis, and a measuring light reflecting mirror that rotates around the optical axis; Light receiving means for capturing the reflected light reflected by the measuring light reflecting mirror, and the reflected light intensity measured by the light receiving means is input;
An optical information processing circuit that appropriately processes the input signal to output light intensity information; and an arithmetic circuit that calculates a fiber orientation index, a fiber orientation angle, and the like from an output signal of the optical information processing circuit, A fiber orientation measuring device for paper, wherein the light reflected by the paper surface is sequentially captured by the light receiving means at least at eight places of the annular reflecting mirror during one rotation of the reflecting mirror. 8. The light receiving device according to claim 6, wherein the light receiving means includes a polarizer for separating polarized light oscillating from reflected light in one of a direction parallel and a direction perpendicular to the incident / reflective surface. Item 7. A paper fiber orientation measuring apparatus according to any one of Items 7. 9. A light projecting means which irradiates a detection light composed of linearly polarized light perpendicularly to a paper surface of a stationary or running paper and rotates about an optical axis, and an incident side of the linearly polarized light on the paper surface. Are arranged around the incident optical axis in synchronization with the rotation of the light projecting means, and the light receiving unit faces the intersection of the paper surface and the incident optical axis and reflects the light reflected by the paper surface of the linearly polarized light. At least one light receiving unit that transmits a polarizer that separates linearly polarized light that oscillates in the same direction as the vibration direction and captures the linearly polarized light, and the reflected light intensity measured by the light receiving unit is input,
An optical information processing circuit that appropriately processes the input signal to output light intensity information; and an arithmetic circuit that calculates a fiber orientation index, a fiber orientation angle, and the like from an output signal of the optical information processing circuit, The paper fiber orientation measuring device according to claim 1, wherein the light reflected by the paper surface is sequentially captured at least at eight points on the turning orbit while the light receiving means is turning. 10. A light projecting means which irradiates a detection light composed of linearly polarized light perpendicularly to a paper surface of a stationary or running paper, and rotates about an optical axis; An annular reflecting mirror for reflecting the reflected light in a direction passing through a fixed point on the incident optical axis, and reflecting the reflected light from the annular reflecting mirror in the direction of the incident optical axis, and centering around the optical axis. A measuring light reflecting mirror that rotates in synchronization with the rotation of the light projecting means, and the reflected light reflected by the measuring light reflecting mirror is transmitted through a polarizer that rotates in synchronization with the light projecting means corresponding to the linearly polarized light. A light receiving unit that captures the linearly polarized light, and a reflected light intensity measured by the light receiving unit is input,
An optical information processing circuit that appropriately processes the input signal to output light intensity information; and an arithmetic circuit that calculates a fiber orientation index, a fiber orientation angle, and the like from an output signal of the optical information processing circuit, A light-reflecting means for sequentially capturing light reflected by the paper at least at eight positions of the annular reflecting mirror during one rotation of the means and the polarizer; . 11. The fiber orientation measurement of paper according to claim 9, wherein the linearly polarized light as the detection light is a polarized light that oscillates in a direction perpendicular to the incident / reflective surface. apparatus. 12. The light receiving device according to claim 6, wherein the reflected light is captured by the light receiving device at a turning orbit of the light receiving device or at a position where the annular reflecting mirror is divided at substantially equal intervals. Paper fiber orientation measuring device.