JPH0457983A - Non-contact orientation meter - Google Patents

Abstract

PURPOSE:To determine the orientation of paper at a small measuring area by projecting a band light through a half mirror and a cone mirror to a paper surface with a specific objective optical means and determining the reflectivity difference between the above light and a band light passed through a light path reverse to the above path and reflected with the half mirror. CONSTITUTION:A light beam projected from a light source 1 is passed through a collimator lens 2 and a diaphragm mechanism 3 to form a band light, which is transmitted through a half mirror 7. The obtained rotating narrow band light is projected to the upper face of a cone prism 8. The light reflected with the upper surface of the prism is passed through cone prisms 9, 10 and projected to the surface of a paper 11 from right and left at an incidence angle theta and the light reflected from the paper is transmitted through a light path reverse to the above path and reflected with the half mirror 7. The reflectivity difference is detected by a detector 13 and the fiber direction of the paper is determined by an arithmetic circuit 14.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a non-contact orientation meter, and more specifically, it is a non-contact online orientation meter that measures the direction (orientation) of moving paper fibers during the papermaking process in a non-contact manner. This invention relates to a non-contact orientation meter that can perform measurements.

<Conventional technology> Conventionally, this type of non-contact type orientation meter uses a conventional fiber orientation method using a laser beam as shown in FIG.
Fiber Orientation (hereinafter referred to as “fibre orientation”)
A schematic diagram of the technology of the measurement system (abbreviated as “FO”)
Figure 6 is a diagram used to explain Figure 5) is known. ).

In FIGS. 5 and 6, A is a laser beam generating means (semiconductor laser) A1. An upper detection sensor includes a laser optical means A2, a mirror A3, etc., and B is an image optical means B provided at the bottom of the paper C.

Mirror B2. As shown in FIG. 6, it is equipped with a diode array B3 consisting of four diodes D1 to D4 for measuring the FO ratio and diodes D5 to D6 for detecting other values related to calculations for paper fiber measurement, an arithmetic circuit 84, etc. This is the lower detection sensor.

In such a configuration that uses one type of sensor on both sides, a semiconductor laser generates a parallel light beam and concentrates it on the paper surface (the projected beam has a diameter of 100 to 200 μm), and this projected beam is bundled inside the fiber of the paper. , which then diffuses the light and propagates it along the fiber. At this time, light traveling along the fibers aligned with the main axis of the FO has a low probability of colliding with fibers that are perpendicular to each other, so the attenuation rate is small. The final spot on the paper web will therefore have a diameter of about The spot becomes circular), and the main axis of the ellipse overlaps with the main direction of the FO.

As a result of the above, the final light spot is enlarged and then projected onto the diode array-83 (represented by Lj in Figure 6), which allows all elements of the ellipse to be calculated mathematically. It becomes possible. That is, the signal obtained here is sent to the arithmetic circuit B4 to calculate the FO ratio and the FO angle (the angle of deviation of the main direction of the FO).

<Problems to be Solved by the Invention> However, such conventional devices are affected by paper thickness and require a relatively large area for measurement, which makes them very difficult to solve in the paper making process. There was a point U between which it is difficult to use paper that moves at high speeds (ie online measurements are difficult).

The present invention was made in view of the problems of the conventional technology, and aims to provide a one-sided sensor configuration, a small measurement area, a short measurement time, and an angle of incidence that is small. The purpose of the present invention is to provide a non-contact type orientation meter that can measure the direction (orientation) of paper fibers in a non-contact manner without undergoing any changes in paper fibers.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides a non-contact method for measuring the orientation of fibers of a non-measurable object in a non-contact manner by applying light from a light source to the object to be measured. In the orientation meter, an optical means for collimating the light from the light source section, an aperture mechanism having a rotating structure having a slit for converting the collimated light into an elongated linear light, a half mirror, and a rotating light source passing through the half mirror. Splitting, distributing, condensing, and integrating means that divides and distributes the elongated fluorescent light approximately at the center, condenses and integrates the returned light after the division and distribution, and returns it to the half mirror. and a rotationally moving division/light distribution unit from the division/light distribution/concentration/integration means.
After the light distribution, the light is sequentially focused onto the object to be measured so that the light beams come from the left and right sides of the same optical path, and this focused rotating light is reversed to the splitting, light distribution, focusing, and integrating means. objective optical means for returning the light on the same optical path; a light detection means for measuring the light reflected by the half mirror of the condensed and integrated light from the splitting, light distribution, condensing and integrating means; The apparatus is characterized by comprising a calculation circuit capable of calculating the orientation of the fibers of the object to be measured based on the signal from the detection means.

After the light emitted from the light source is collimated, it passes through a diaphragm with a rotating long and narrow slit, becomes a long and thin line of light (hereinafter referred to as "fluorescence J"), and heads toward the half mirror. This passed fluorescent light enters from the top surface of the conical prism, and then is reflected from this top surface portion and heads toward the first umbrella-shaped internal reflection mirror or cone prism. The fluorescent light reflected by the surface is directed to another book-shaped internal reflection mirror or cone prism, and the fluorescent light reflected from the umbrella-shaped internal reflection mirror or cone prism is applied to the paper surface to be measured at a predetermined distance. At this time, the fluorescent light comes from the left and right sides of the same optical path.As a result, the fluorescent light that is not reflected by the paper (hereinafter referred to as "reflection band light") is The light travels through the conical prism through the opposite optical path to the half mirror above the conical prism, and after being reflected by the half mirror, enters a detector that measures the difference in reflectance of the reflection band light.

Here, in the case of reflection by paper, the reflectance is highest when the direction of the fibers and the direction of the optical axis are parallel, and the lowest when the opposite is the case.

Thus, the orientation of the paper can be measured by this difference in reflectance. In other words, the fluorescent light on the surface of the paper formed based on such an optical system does not rotate at high speed, and after propagating the result of this rotation through the same path, it enters the detector from the half mirror. Regarding the amount of light, it is measured that the direction showing the maximum value is the direction of the fiber. Such an optical system is also characterized in that, since the fluorescent light enters from the left and right, changes in reflectance due to changes in the angle of incidence on the paper are canceled out.

<Example> Examples will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a specific embodiment of the non-contact type orientation meter of the present invention. Further, FIGS. 2 and 3 are diagrams for explaining FIG. 1.

In FIGS. 1 to 3, 1 is a light source section.

This light source section may be composed mainly of a laser device, or, for example, as shown in the figure, a commonly used light source 1a is used and the light from this light source is spread by an optical means 1b. The light source section 1 may be configured to emit light after being reflected by the reflecting mirror 1d through the diaphragm (pinhole) 1c, but there are no particular limitations on the structure, etc. of this light source section 1.

2 collimates the light emitted from light source section 1 (parallel light)
This is an optical means (hereinafter referred to as "collimating lens") that

As shown in FIG. 2, reference numeral 3 designates an aperture mechanism having an elongated slit 3a in its central portion and converts the collimated light into elongated linear light, so-called fluorescent light.

This diaphragm mechanism 3 is configured to rotate in a predetermined direction about the fluorescent light with its central part as the rotation center axis, and for this purpose, for example, as shown in the figure, a gear mechanism is provided on its outer periphery (of course (Although it may be a rotation transmission mechanism),
Another gear mechanism 4 that meshes with this gear mechanism can be configured to be rotated by the motor 5. The slit 3a of the aperture mechanism when rotating as shown in FIG.
The rotational position of can be detected and measured, for example, by arranging the encoder 6 on the other side of the gear 4 (or on the opposite side of the aperture mechanism 3).

8 divides the rotating elongated fluorescent light that has passed through the half mirror 7 around its center and distributes (spectrums) the light to a series of optical systems to be described later. In order to condense and integrate the light (light), it has a conical shape so that the fluorescent light incident on the top surface is divided and distributed near the center of the fluorescent light, and is reflected by a part of the conical top mirror, which will be described later. Splitting, distributing, condensing, and integrating light beams directed toward a series of optical systems, and at the same time, the return light from this series of optical systems is reflected by a portion of this upper mirror and directed toward the half mirror 7, for example, by a conical prism or a conical mirror. means (hereinafter referred to as a "conical mirror").

K focuses the distributed half-fluorescent light on the paper 11, which is the object to be measured, after being divided by the conical mirror 8, and converts this focused light (measuring light) into a cone again. This is an objective optical means consisting of the series of optical systems mentioned above that collects (returns) the light onto the mirror 8. This objective optical means can be constructed of, for example, a pair of umbrella-shaped internal reflection mirrors or a cone prism.

It goes without saying that one of these may be an internal reflection mirror and the other a cone prism, or vice versa, or both may be the same.Therefore, here we will use a cone prism. The following explanation will be given assuming that a pair is used.

What is important here is that the reflecting surfaces face each other in a straight line (therefore, the installation configuration may be as shown by the broken line in Figure 1), and in this case, the upper cone prism (hereinafter referred to as " The main-shaped inclination angle of the reflecting surface 9a of the first cone prism (referred to as "first cone prism") 9 is such that the optical path (light trail) of the reflected rotating semi-fluorescent light is formed by the diaphragm mechanism 3, as shown in FIG. When the fluorescent light travels parallel to the rotation center axis OL, it is determined by the angle relationship of the reflecting surface of the conical mirror 8. In addition, the lower cone prism (hereinafter “second
The inclination angle of the reflecting surface 10a of the cone prism 100 reflects the rotating half-fluorescent light from the first cone prism 9 on the half-slanted surface 10a onto the central axis of rotation oL of the surface of the paper 11. It is set so that it can be projected at a predetermined angle θ. This means that by projection, light beams come from the left and right on the same optical path, so that they appear as fluorescent light on paper. If arranged like this, the paper fibers of the projected light
The reflection band light having an intensity based on the direction is guided to the conical mirror 8 through the opposite optical path.

13 is about the light (reflection band light) reflected by the half mirror 7 of the light which is collected by the conical mirror 8 and becomes a band shape again.
This condensing lens 12 after being condensed by the condensing lens 12
This is a detection means for measuring the difference in reflectance installed at the focal position of the This detection means 13 allows the intensity of the measuring light to be 0/
The E-converted (optical/electrical converted) signal is sent to the arithmetic circuit 1.
Guided by 4.

Therefore, in the calculation circuit 14, based on the position of the slit detected by the encoder 6, that is, the position of the fluorescent light on the paper surface, and from the correlation with the intensity of the measurement light, the fiber direction when reflected by the paper is determined. The orientation of the paper is calculated based on the fact that the reflectance is highest when the optical axes are parallel, and the lowest when the opposite is true.

The operation of such a configuration will be explained below.

The light emitted from the light source section 1 is collimated by the collimating lens 2, becomes rotating fluorescent light at the slit 3a of the rotating aperture mechanism 3, and heads toward the half mirror 7. The rotating fluorescent light that has passed through the half mirror is directed to the conical prism 8. In the 0-cone prism 8 directed toward the 0-cone prism 8, the rotating fluorescent light is split at the center and distributed as a half-fluorescent light to the first cone prism 9. The first cone prism 9 further guides this rotationally distributed semi-fluorescent light to the second cone prism. Therefore, the second cone prism 10 guides the rotationally distributed semi-fluorescent light at an angle θ to the central axis of rotation of the paper surface. Light is focused from the left and right on the same optical path so that it becomes fluorescent light on the oL. The collected fluorescent light on the surface of the paper rotates in accordance with the slit 3a. At this time, since the fluorescent light enters from the left and right, changes in reflectance due to changes in the angle of incidence on the paper are canceled out.

This rotated and focused light then propagates through the opposite optical path as reflection band light according to the brightness based on the orientation of the fibers of the paper, and is collected (returned) by the conical mirror 8. The reflection band light collected and integrated by the 0-cone mirror 8 is directed toward the half mirror 7, and the reflection band light reflected by the half mirror 7 is collected by the condenser lens 12 and sent to the detection means 13 as measurement light. It is measured that the direction showing the maximum value of the amount of incident light is the direction of the fiber. In other words, the measurement light measured by the detection means is converted into an electrical signal and guided to the arithmetic circuit 14, and the arithmetic circuit calculates it based on the signal from the encoder 6, and as a result, the paper 11
The orientation of is measured.

<Other Examples> The present invention is not limited to the contents described above.
For example, the configuration may be as follows.

■: For example, if the surface of the paper 11 is coated with a coating material (laminate) or the like 11a as shown in the explanatory diagram for other embodiments in FIG. 4, the structure of FIG. If left as is, it will be reflected on the surface as shown by the broken line α in Figure 4, so in order to avoid this, the slit 3a is
P polarized light (P Measures such as attaching a polarizing plate (not shown) in the direction in which the light is reflected by the surface of the fiber 11b inside the fiber 11b are taken.

By taking such measures, as shown in Figure 4,
The incident light (incident at the Brewster angle depending on the refractive index of the coating material) passes through the coating material 11a as shown by the solid line, and it becomes possible to measure the direction of the internal fibers as described above.

■: Instead of the detection means 13 configured to perform O/E conversion in FIG. 1, a camera such as an ITV may be used as the detection means, and in this case, the position of the slit remains unchanged for image detection. Therefore, the encoder 6 becomes unnecessary. That is, in this case as well, it is possible to measure the direction (orientation) of the fibers, although the sensitivity is lower than that described above. At this time, it is also possible to detect the structure (irregularities) on the paper surface. In this case, it goes without saying that the arithmetic circuit should also have a corresponding configuration (for example, a function capable of image analysis, etc.) and functions.

■: If a laser is used as a light source, the structure on the paper surface can be observed as speckles.

■: For example, regarding division, light distribution, light concentration, and integration methods,
For example, when looking at division, it is sufficient to divide the rotating band of light that has passed through the half mirror around its center, so the apex facing the half mirror may have a somewhat flat shape as shown in Figure 1. It suffices if the structure is such that it can divide, distribute, condense, and integrate the light rotating before and after it.

<Effects of the Invention> Since the present invention is configured as described above, it produces the following effects.

■The orientation of fibers inside two papers can be measured without contact.

■: Since the optical path is not one-sided, that is, the light travels left and right on the same optical path, changes in reflectance due to changes in the incident angle are canceled out.

■It can be made smaller because it has a two-rotation symmetrical optical system. Moreover, since the sensor can be used on one side, the device as a whole can be made smaller from this point of view as well.

■: Since the measurement time is short, online measurement is possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a specific embodiment of the non-contact type orientation needle of the present invention, FIGS. 2 and 3 are illustrations for explaining FIG. 1, and FIG. 4 is an explanation for other embodiments. Figure for, No. 5
The figure is a schematic configuration diagram of a technology of a conventional fiber orientation measurement system using a laser beam, and FIG. 6 is a diagram for explaining FIG. 5. DESCRIPTION OF SYMBOLS 1... Light source part, 2... Optical means (collimating lens), 3... Aperture mechanism, 7... Half mirror 18...
・Dividing, light distribution, focusing, integrating means (conical mirror), K...
- Objective optical means, 11...paper, 12...condensing lens, 13...detector. Figure 1

Claims (1)

[Claims] A non-contact orientation meter that measures the orientation of fibers of a non-measurable object in a non-contact manner by applying light from a light source to the object, includes an optical means for collimating the light from the light source, and an optical means for collimating the collimated light. A diaphragm mechanism having a rotating structure having a slit that converts light into elongated linear light, a half mirror, and a rotating elongated light band that has passed through the half mirror and is divided approximately at the center.
Splitting, distributing, concentrating, and concentrating the returned light after the division and distribution, and returning it to the half mirror.
A integrating means and a rotationally moving split/distributed light from the splitting/light distribution/focusing/integrating means are sequentially focused onto the object to be measured so that the light beams come from the left and right with respect to the same optical path. and an objective optical means for returning the condensed rotating light to the division/light distribution/concentration/integration means through the same optical path in the opposite direction; and an arithmetic circuit capable of calculating the orientation of the fibers of the object to be measured based on at least a signal from the photodetecting means. Features a non-contact orientation meter.