JPS6324147A - Device and method of detecting feature of paper-like articles - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background Art] This application is filed by George B., Parent
Jr., Glenn W., Zeiders and Jam.
Filed on January 8, 1985 by es P.
Apparatus and Method for Detecting Multiple Characteristics of Paper-like Materials'' (U.S. Application No. 817,273), a continuation-in-part application.

The present invention relates to a method and apparatus for detecting parameters of a paper-like material, and more particularly to a method and apparatus for detecting a plurality of parameters of a paper-like material produced on a continuously moving web.

When manufacturing raw materials, it is often desirable to monitor one abnormal parameter of the manufactured product. Particularly in the paper manufacturing industry, it is particularly important to constantly monitor the thickness and moisture content of the web of paper manufacturing machinery.

Furthermore, it is desirable to continuously measure the basic charge of paper, that is, the weight per unit area.

Various methods are known for performing such monitoring and measurements. For example, the moisture content of a moving web can be measured by microwave technology, such as that disclosed in US Pat. No. 4,484,133. According to this microwave technique, the signal regarding the water content output from the microwave energy is corrected for the thickness of the paper.

Various methods are also known for monitoring web thickness. Some of these techniques include, for example, U.S. Pat.
There is a technique disclosed in No. 0 that uses microwaves to determine the total thickness of moving paper.

However, there is no known technology, including the above-mentioned US patent, that discloses means for simultaneously generating spatial shapes of moisture and thickness over the entire width of the web. Therefore, it is desirable to be able to obtain such spatial shapes at the same time.

Techniques for measuring basis weight are also known in the art. However, conventional basic weight measurement techniques are not capable of displaying the absolute value of the basic weight as well as the thickness and moisture content over the entire width of the web. Additionally, prior art techniques for measuring web surface parameters often involve complex moving part scanning mechanisms. Accordingly, it would be desirable to provide an apparatus and method for simultaneously generating moisture, thickness, and basis weight spatial geometries without moving parts of the sensing device.

SUMMARY OF THE INVENTION According to the invention, a paper sheet comprising a beam of electromagnetic radiation, comprising radiation generating means for generating a plurality of beams having different frequencies and directing the beam onto the paper-like material at a suitable angle of incidence. An apparatus for detecting characteristics of a type is provided. The apparatus further comprises first signal generating means for generating different reflected and transmitted signals for each beam proportional to the intensity of each beam reflected from and transmitted through the paper. ,
and processing means for outputting moisture and thickness signals calculated from the plurality of reflection and transmission signals. In a preferred embodiment, the radiation generating means preferably comprises a plurality of microwave oscillators generating microwave signals of different frequencies. In the apparatus of the present invention, a plurality of such radiation generating means are spaced apart from each other over the entire width of the moving paper web.

In a preferred embodiment, the processing means also outputs a ratio of reflected and transmitted signals for each frequency to analyze the constructive and/or destructive interference effects of the coherent microwave radiation on the moisture content and thickness of the paper. Solve the simultaneous equations.

In a first embodiment, the device has second generating means for generating a base signal proportional to the base weight at the base position;
As a result, the processing means generates a spatial shape of the dry basis weight of the paper-like material calculated from the reference signal and the moisture and thickness signals.

In a second preferred embodiment, the apparatus of the invention comprises an incident signal generating means for generating a different incident signal proportional to the intensity of each beam incident on said paper material. The apparatus further includes processing means for outputting moisture, thickness, and sample weight signals calculated from the plurality of incident, transmitted, and reflected signals. In a second embodiment, the radiation means comprises a plurality of microwave transmitters generating microwaves 12 of different frequencies. The apparatus of the invention includes a plurality of such radiation generating means spaced apart over the entire width of a moving web of paper-like material.

The processing means outputs the ratio of the incident signal to the transmitted signal for each frequency and solves a system of equations to analyze the constructive and/or destructive interference effects of the coherent microwave radiation with respect to the moisture content, thickness and basis weight of the paper. .

The invention employs the principles of constructive and destructive interference caused by reflection and refraction of coherent radiation. Therefore, a brief explanation of this principle is useful in explaining the preferred embodiment of the invention.

Some reduction occurs when a beam of coherent radiation, such as microwave radiation, is directed into a dielectric material with a finite thickness. A portion of the incident radiation is reflected from the first surface, the unreflected portion passes through said surface 2 and is partially absorbed by the internal material. The radiation incident on the interior impinges on the second surface of the dielectric material and is reflected from within the dielectric material. This process of transmission, reflection and absorption is repeated until the microwave energy is reduced to zero. These processes occur regardless of the conditions of the incident radiation. That is, the same phenomenon occurs whether the microwaves are parallel, focused, or diffused. However, the way in which the components that are repeatedly reflected or transmitted interact with each other strongly depends on the coherent state of the incident radiation.

If the beam is not diverging, the reflected or transmitted components are said to be "coherently increasing." Both constructive and destructive interference can occur, ie radiation components can combine in-phase or out-of-phase. In each case, the radiation components are combined in a constant phase relationship determined only by the microwave wavelength, dielectric thickness, refractive index, and geometry.

When the incident radiation is diffused, reflection and transmission occur over a wide range of angles. Its effect is intricately dependent on the geometry of the dielectric material as well as the detailed description of the beam shape. When using a microwave beam to measure, for example, the moisture content of paper, the geometry of the measurement needs to be carefully analyzed. Each transmitted component passes through a thicker paper sheet containing a higher water content than the previous one, and for each component the paper sheet appears thicker than the previous component. These phenomena are well known and have influenced the design of many conventional systems using microwave measurements of water content.

FIG. 1 shows a dielectric sheet of paper 18 of thickness H with parallel sides. Identical parts are designated by the same numbers in the drawings. A coherent beam of microwave radiation is incident at an angle a to the vertical and is shown in FIG. 1 as a single beam A. The part of this beam reflected from the front surface is ray AI. The portion transmitted through the paper is shown as 8 oblique rays B1 from the opposite side. Ray B1 passes through the paper once, but its path length is not equal to H, but equal to H divided by the cob in of a'. In this case, a' is the angle that ray B1 makes with respect to the vertical while passing through the interior of paper 18. The angle a'' is determined by Snell's law. The part of the beam A reflected from the lower surface and transmitted through the upper surface is denoted by A2. The ray A'' is
Because it passes through twice, it receives an attenuation equal to the path that passes through the paper twice the thickness of the paper 18. The portion of beam A that is reflected from the top surface and transmitted to the bottom surface is indicated by B2.

As can be seen from Figure 1, three paths are created to pass through the paper. This process continues until the transmitted and reflected components of beam A are zero.

As can be seen from FIG. 1, if the total reflected energy is collected in one collector and the total reflected energy is collected in another collector, then both the transmitted energy and the reflected energy are absorbed by the paper 18. It is a complex function of the thickness H of paper and the absorption coefficient of paper]8. Absorption is a function of the water content of the paper and the dielectric constant of the dry paper.

Thickness must be taken into account in order to construct a microwave system for measuring the water content of paper.

In the prior art, it is known that energy measurements including reflected, transmitted, and absorbed components are affected by several components and multiple reflection phenomena. A feature of prior art methods is to minimize or compensate for the effects of such phenomena.

However, when the thickness of the paper changes, the prior art, which includes compensation and assumptions for simplicity, is not effective.

In this invention, the coherent influence is not compensated for in order to eliminate the dependence on paper thickness. Instead, the effect is used to simultaneously determine paper thickness and moisture without making any assumptions. That is, simultaneous measurements are performed by simultaneously irradiating the paper with 29 radiation fAJ beams having different wavelengths. This results in 29 equations with 29 unknowns for each point where transmission and reflection are measured. By solving these 29 simultaneous equations, the thickness and moisture content can be determined. In some applications, its validity can be checked by measuring the third wavelength.

The reflected and transmitted energy of the paper-like material to be analyzed can be expressed as the ratio R/T of the reflected power and the transmitted power.

The ratio R/T of the transmitted power to the reflected power can be reduced to the product of 29 functions of the complex refractive index of the water-containing paper n+ik, where the "surface coefficient" is 52 and the "bulk" coefficient is S i n2.

However, H represents the thickness of the paper, λ represents the wavelength, and both H and λ have the same unit.

Here, the water content is 0.1 to 60%, and the paper thickness is 0.0%.
01-0.25, the ratio R/T can be approximated as follows.

Therefore, the paper thickness H and water content M are given by the parametric solution of the above equation for the 29 variables H and M. From M, n(!=k is determined by the following equation.

n-np(1-M) +nv-M k=k (1-M) +k-M...(
5) v Here, it is the actual refractive index and stratified refractive index of the rolled paper to be measured.

Further, n and kp are the real refractive index and polarized refractive index of water, and are experimentally determined values. These values can be approximated by the following equation in the frequency range of 30 to 100 gigahertz (0.3 cm - 1.0 cm).

n+, -3,33λ+2.067 kw-4,08λ-2,04λ2 +0.98 -(
6) 0°3<λ<1.00z FIG. 2 is a block diagram of a system 10 embodying the present invention. A pair of transmitters 12 and 14 generate electromagnetic radiation at frequencies fl and fl, respectively. The wavelength of the highest frequency should be at least four times the thickness of the paper-like material being analyzed, so as not to obscure the results obtained.

In the preferred embodiment, transmitters 12 and 14 generate microwave radiation at 94 gigahertz and 47 gigahertz, respectively. Signals from transmitters 12 and 4 are fed to transmit antenna 16. Transmit antenna 16 outputs a pair of beams of coherent micro-radiation. This pair of beams is irradiated onto a sheet of paper 18 in the incident area. Accordingly, the present invention provides a radiation generating means that generates a plurality of beams of coherent electromagnetic radiation, each having a different frequency, and irradiates the paper material in the incident area with the beam. As shown in the embodiment, this radiation generating means includes a transmitter 1
2.14 and an antenna 16.

As can be seen from FIG. 2, a portion of the beam emitted by the antenna 16 is reflected by the paper 18 and reaches the reflected signal receiving antenna 20. The first and second beams having frequencies fl and fl are directed to the first and jX2 reflected signal detectors 22,24. Detectors 22 and 24 output reflected signals proportional to the intensity of each beam of each frequency reflected from paper 18.

A transmitted signal receiving antenna 26 is placed below the paper 18 and collects the first and second beams from the antenna 16 that have been transmitted through the paper 18. Antenna 26 directs the transmitted beam at frequencies fl and f2 to first and second transmitted signal detectors 28.30. Detectors 28 and 30 are paper 1
A transmission signal proportional to the intensity of each beam transmitted through the 8 is output.

Therefore, the invention provides a first signal generating means that generates different reflected and transmitted signals for each beam.

These signals are proportional to the intensity of the beam reflected from and transmitted through the paper material being analyzed, respectively. As shown in the embodiment, the first signal generating means includes a transmitted signal receiving antenna 26, first and second transmitted signal detectors 28.30, antenna 20, and first and second reflected signal detectors 22.24. configured.

The reflected and transmitted signals from the detectors 22.24.28.30 are the ratio signals Rfl/Tfl and Rf 2/T
is fed to a signal processor 32 which outputs f 2 . The ratio signal is a signal having a value proportional to the ratio of the intensities of the microwave radiation reflected from the paper 18 and the microwave radiation transmitted through the paper 18 for the first and second frequencies. This ratio signal is supplied to the computer 34 and is expressed by the formula (4
), the moisture signal and thickness signal are obtained. Computer 34 outputs signals representative of moisture content and thickness and provides them to display 36. Various configurations of the signal processor 32, computer 34, and display device 36 are possible. For example, the signal processor 32 may be connected to the detector 22.2.
4.28.30 to convert the reflected and transmitted signals into digital signals, and a microprocessor to calculate the digital ratio signal R/T. The computer 34 can be an IBM PC personal computer with medium class capabilities, for example. The display device 36 may be composed of a CRT display device that displays the moisture content and thickness values in alphanumeric characters, or may be composed of a plurality of numerical digital readout devices. The functions of signal processor 32 and computer 34 may also be performed by a plurality of analog-to-digital converters that provide output signals directly to the computer that calculates the ratio signal and solves equation (4) as described above.

The transmitter 12, 14, the transmitting antenna 16, the reflected signal receiving antenna 20, and the detectors 22 and 24 constitute a reflecting device that outputs a reflected signal. Transmission signal reception f<
The antenna 26 and the detector 28.30 constitute a transmission unit 40 which outputs a transmission signal.

FIG. 3 further shows a block diagram of a preferred embodiment of the invention. As can be seen in FIG. 3, a plurality of reflection units 38 and transmission units 40 are arranged on either side of a web 18 made on a fourdrinier machine and moving in the direction of arrow 42. Third
The transmitted and reflected signals at frequencies designated It and Ir, respectively, are provided to a signal processor 32.

As shown in FIG.
0 can be connected to a single signal processor 32. Signal processor 32 outputs digital signals representative of the intensity of microwave radiation reflected from and transmitted through the web for each frequency at various locations on the web. This intensity signal is
4 and the ratio signal R/T is calculated. Conversely, in some applications it may be better to connect signal processor 32 to the outputs of reflection unit 38 and transmission unit 40 and have signal processor 32 calculate the R/T signal.

Additionally, FIG. 3 shows a basic monitor 44 which generates a signal proportional to the basis weight of the moving web 18 at a fixed location at the end of the web 18. The output of base weight monitor 44 is provided to a second signal processor 46. Processor 46 converts the analog signal output by monitor 44 to a digital signal and performs appropriate scaling functions before providing it to computer 34. In a preferred embodiment, the base weight monitor includes:
Ohmart corporation
Type 1000 of n) is applicable. Type 1000 outputs a group of beta radiation from a radioactive cesium source and uses a radiation detector to measure the amount of beta radiation transmitted through the moving web 18. The radiation detector outputs an analog signal proportional to the electron population received. Note that other types of basic weight monitors, such as a combination of an electron gun and a detector, may also be used.

The signals from the monitor 44 are processed by a signal processor 46 and the computer 34 outputs a signal from the web 18 to the right side of the web 18, as shown in the position of the monitor 44 on the right side of the web 18.
is converted into a signal representing the peripheral basis weight of the wet paper at a reference position spaced from the edge of the paper.

The reflection unit 38 and the transmission unit 40 transmit the intensity signal 1
Output r and It. These signals are sent to computer 3
4 is a web 18 in a direction perpendicular to the direction of arrow 42
Outputs ratio signals at multiple positions. frequency f] and f
These ratio signals relative to 2 are used to calculate moisture content and thickness values for each location on the web in the manner described above. The web moisture content value at the location of the basis weight monitor 44 is combined 911 with the wet basis weight value from the monitor 44 to output the dry basis weight at the monitor location according to the following equation:

Dry basic weight (monitor) Peripheral wet basic weight (monitor x (1 - moisture)) The thickness of the web is combined with the basic serious injury value at the monitor position to generate the spatial shape of the dry basic weight of the web. You can.

Figure 4 shows the roll paper output 1 of a 300-inch fourdrinier machine.
FIG. 4 is a perspective view of a 32-position sensing array 46 that outputs a spatial profile of 8" widthwise thickness, water content, and basis weight. Although there are areas between the arrays that cannot be covered, most of the area is The properties of the paper across the width of the web are detected by an array of 32 locations, and in many applications such void areas are not important.In some applications, it may be desirable to have closer spacing between arrays. In this case, the spacing of the arrays 46 can be narrowed.If the arrays 46 are spaced sufficiently apart, they can necessarily be monitored continuously across the width of the web. .

On the far right side of FIG. 4, a pair of reflection units 38 are mounted on both sides of the board 48, and the reflection modules 5
It constitutes 0. A pair of transmission units 40 are mounted on both sides of the board 52, and a transmission module 54 is mounted on each side of the board 52.
It consists of

Array 46 has sixteen reflective modules 50, each mounted on a reflective frame 55 consisting of a plurality of horizontal upper reflective support beams and a plurality of lower reflective support beams. The reflective frame 56 is arranged in parallel, that is, each reflective module 5 is arranged side by side in a horizontal plane.
Supports 0.

Array 46 has a transmissive frame 62 formed by a plurality of horizontal upper transmissive support beams 64 and lower transmissive support beams 66. The transmission frame 62 supports the transmission module 52 arranged parallel to the horizontal plane of the reflection module 50 .

Array 46 further includes moving web 18 to be analyzed.
A vertical support member 68 supports the transmissive frame 62 and the reflective frame 56 to define an elongated aperture through which the
Consists of. Vertical support member 68 supports reflective module 50
are supported in one-to-one correspondence in the vertical direction. As a result,
A corresponding pair of reflection units 38 and transmission units 40 are aligned with equidistantly spaced incidence areas of the moving web 18'. Therefore, the present invention has a reflective module and a transmissive module in the horizontal plane extending parallel to each other;
The apparatus comprises means for supporting a reflective frame and a transmissive frame to define an aperture for receiving the web to be analyzed. The supporting means supports the reflective module and the transmissive module in a one-to-one correspondence in the vertical direction. As shown in the example, the support means consist of a vertical support 68.

A cable tray is formed between the upper reflective support beam 58 and the lower transmissive frame 62 and has a plurality of cables 72 connected to each reflective and transmissive unit 40. Cable 72 is connected to a power supply module 74 that supplies operating voltage to reflection unit 38 and transmission unit 4o.

Cable 72 is further connected to computer 34 at a suitable location remote from array 46.

Accordingly, computer 34 and display 36 are not shown in FIG. A cable 72 is connected to each transmission and reflection detector 22.24.28.30 via the signal processor 32 of each reflection and transmission module. The invention therefore provides means for connecting each transmission and reflection detector to the processing means. As shown in the embodiment, such a connection means is connected to the signal processor 3.
2 and a cable 72.

Note that the reflection unit 38 or the transmission unit 40 has two
The reflective module 50 or the transmissive module 54 may be configured with nine or more or fewer than nine. The design may include cost considerations, processing power issues of the signal processing sensor 32, or other compromises well known to those skilled in the art.

The details of the configuration of the reflection unit 38 and the transmission unit 4o are shown in FIG. Transmitter 12 is 47? It consists of a Gunn diode that generates a microwave carrier frequency of Δ and rutz. The FM modulator is installed in the transmitter 12,
It is not visible in Figure 5.

This two-week machine cooperates with transmitter 2 to perform FM modulation at 20 KHz. The output of the transmitter 2 is connected to a conical horn antenna 8o forming a beam 8].

The transmitter 14 consists of a Gunn diode transmitter 2g outputting a microwave carrier frequency of 94 GHz. A modulator, not visible in FIG. 5, is mounted within the transmitter 14,
Modulate the carrier frequency of the oscillator 14 with a frequency of 21 KHz. The output of transmitter] 4 is a conical horn antenna 82
and forms a beam 83 polarized in a direction orthogonal to -1,81. Transmitters 12 and 14 are American Mil
litech of 5outhDeerfield
It can be constructed using GDM gunn diodes manufactured by d company.

Beams 81 and 83 are reflected by mirrors 81 and 90;
It is directed to a dielectric supported grid filter 84 which acts as a beam combiner.

Mirrors 88 and 90 are off-axis knife mirrors, which can be provided, for example, of the GMP type from Millitech. The polarization of emitters 2 and 14 and the orientation of the grid filter are such that beam 81 is reflected from one surface of filter 84 and beam 83 is routed through filter 84 such that beams 81 and 83 are combined in a common path. It is inevitably meant to pass unhindered. The combined beam passes through a millimeter microwave planar hyperbolic lens 86 of dielectric material known under trademarks such as REXOLITE, TEFLON, or TPX. Combined beam 81.
83 passes through lens 86 and window 88 and is imaged onto an incident area 90 of web 18'.

Therefore, the present invention provides the first and second beams 81 .
Imaging means for parallelizing 83 and focusing the image on the web 18' to be analyzed are arranged downstream of the filter 84 (which functions as a beam combiner). As shown in the embodiment, the first focusing means is constituted by a lens 86.

The reflection unit 38 further includes a second lens 92 which receives a portion of the beams 81 and 83 reflected from the web 18'.
are doing. Beams 81 and 83 passing through lens 92 are
The image is focused on a reflective beam splitter 94 consisting of a grid filter supported by a dielectric. grid filter 8
4 and 94 are, for example, M i l l i t e c
A GDS filter from company h can be used. The reflection unit 38 also includes first and second reflection detectors 22.24.
have. The detector 2.24 consists of a detector that detects polarized light. Such detectors may consist, for example, of Schottky barrier beam lead diodes receiving 47 GHz and 94 GHz, respectively. Detector 22.24 is M i 1 + i t
A DXP type flat surface detector manufactured by ECH Corporation can be used.

The orientation of detectors 22 and 24 and the orientation of reflective beam splitter 94 are configured such that first beam 81 reflected from reflective beam splitter 94 is directed to detector 22 . Beam 83 necessarily passes unimpeded through reflective beam splitter 94 to detector 24 .

The invention therefore includes second imaging means for receiving and imaging the first and second beams reflected from the web being analyzed. As shown in the embodiment, the second imaging means comprises a lens 92.

The transmission means 40 transmits the beam 81 transmitted through the web 18'.
．． 83 has a lens 100 oriented to receive a portion of 83. The lens 100, like the lens 86.92, is manufactured by MILITECH.
shaped lenses can be used. A portion of the transmitted beams 81.83 is guided to the transmitted beam splitter 102 via the lens 100. The transmitted beam splitter 102 consists of a grid supported on a dielectric material, such as a GDS from Mitech. The transmission unit 40 further includes transmission detectors 28 .
A portion 83 of the transmitted beam is directed via beam splitter 102 to detector 28 and then necessarily through beam splitter 102 and antenna 106 to detector 30 .

The reflection unit 38 and the transmission unit 40 constitute a Gaussian microwave optical system, and the beams 81 and 83 have a Gaussian distribution of electric field in a direction perpendicular to the axis of propagation. Such a Gaussian beam retains its shape as it propagates away from its smallest diameter portion, ie, the beam waist.

The beam waist can be reimaged by lenses such as lenses 86 and 92 shown in FIG. The input and output waists shown in FIG. 6 are determined by the particular physical configuration and refractive index of the lens. In the preferred embodiment, lens 86 images combined beam 81.83 to form an output waist in the area of incidence of web 18.

The lens 92 is formed such that its input waist is also larger than the output waist of the lens 96. In this manner, the values of the reflected and transmitted signals provided by units 38 and 40 are not affected by the slope of the surface of web 18. In the preferred embodiment, the output waist of lens 86 is 0.
．． 6 cm and 1.5 cm, and the input waist of lens 92 is 2.5 cm.

It is not necessary to modulate and polarize beams 81 and 83 in orthogonal directions. However, by modulating and polarizing the beam with different modulation frequencies,
A ratio signal R/T with a more accurate value can be obtained. Furthermore, oscillator 12 and oscillator 1 of adjacent reflection units
Different weird 3 for 4! By selecting the I frequency, the insulation between the reflective modules is increased. As a result, the total number of modules for a given width of the web 18' can be increased, and detailed analysis of the parameters in the width direction of the web can be performed.

However, to obtain the benefits of this invention at the lowest cost, the transmissive and reflective modules are all identical. The modulator of such a module has a variable modulation frequency.

Each module is a part of the signal processor 32, and the reflection module and transmission module are mounted on a separate microprocessor 32a mounted on the board.
and 32b. Each module slides and plugs into each associated frame. Each slot in the transmissive and reflective frames is specified during fabrication of the correlated array with a particular sublayer wavenumber selected to maximize isolation from adjacent modules. This slot has a coded connection means, such as an 8-pin female connector.

Each bin of the connector is connected to a logic low level or logic high level voltage source. Each transmissive and reflective module has an 8-bin male connector 110 that is compatible with the female connector in each slot. When the modules are fully installed in their associated slots, the male connector of each module will be connected to a logic high level or logic low level signal. A microprocessor 32a and 32b onboard each module is connected to the correlated 8-bin male connector and interprets the logic pattern to set the modulation frequency of the modulator correlated to the modulator 12.14 of each reflection module. do.

In this way, optimal modulation frequency can be obtained for maximum performance and isolation, while retaining the same hardware advantages of each module? (You can.

Of course, various modifications can be made to this invention. For example, in the embodiment shown in FIG. 4, a reflective module is mounted above the moving web and a transmissive module is mounted below. However, the configuration may be reversed. Furthermore, the transmissive frame and the reflective frame do not have to be physically connected as shown in FIG. In some applications, a reflective frame may be mounted on the underside of the moving web, and a transparent frame may be mounted a dynamic distance above the moving web. It is also possible to mount the transmissive module above the ceiling, as long as proper design provides adequate alignment between the operating transmissive and reflective modules.

It may also be desirable to obtain a ratio signal measured at a third frequency. In particular, it may be desired to take the third frequency measurement at the same location at the end of the web as the basis weight monitor 44. In order to obtain the ratio signal R/T at the first and second frequencies fl, f2 at intervals in the width direction of the web, and to perform the determination of the basis weight m11 depending on the water content at that position. It is also possible to measure the electron absorption rate at the frequency of 11).

The second step is to solve the above equation (4) to obtain the real component and the pseudo component of the refractive index of the wet paper, and to obtain the ratio signal R/T of the frequencies f1 and f2 in the width direction of the web, and the equation The solution is to obtain a signal representing the moisture content and thickness. Finally, the density and basis weight are calculated using these results, and the surrounding dead tree weight and absolute dry basis weight values are obtained, and the spatial shape in the width direction of the paper roll is obtained.

FIG. 7 is a flowchart showing the processing of the computer 34. At block 400, the intensity value It of the transmitted signal is determined by the total transmission unit 40.
Read from. At block 402 it is determined whether the reading is correct. If correct, the reflection unit 38
The reflected intensity signal Ir outputted by is read at each position and at each wavelength. At block 406 it is determined whether the reflection reading is correct.

At block 408, the correct readings are used to calculate the R/T ratios for the 29 wavelengths at all locations. Validity is checked again at block 410. If all ratios are correct, the reflected and transmitted intensity values at the third wavelength measured at the location of basis weight monitor 44 are read.

The validity of these values is checked, and if correct, the refractive index n at each position is calculated from the R/T ratio of the three wavelengths in the block 4.
16. If these values are determined to be correct at block 418, the moisture content and thickness for each location are calculated at process 420 by solving equation (4).

At block 422, a measurement of the surrounding basis weight is made by the monitor 44. The dry base iW at the monitor 44 location is calculated from the moisture content at the monitor 44 location and the surrounding base weight value at block 424 . At block 42611-, concentration is calculated from the thickness and dry basis weight. Next, at block 428, the bone dry basis weight at all points is calculated from the moisture content, thickness, and concentration. This information is displayed at block 430.

If an incorrect reading is detected at block 402, the reading is deleted at block 404. The deletions are counted and accumulated at block 432 and summed at block 434. Similar deletion count values are block 406.436.438; block 41
0°440.442; and block 414.444,
442. All delete values are block 43
4 is added. If the total number of deletions exceeds a predetermined limit, error indication data is generated at block 444 and displayed at block 430.

In a second embodiment, a signal indicative of basis weight is calculated directly from the radiation signal in the same way as water content and thickness. In particular, such a basis weight signal is calculated from the ratio of the transmitted and incident radiation of the web 8 and the ratio of the reflected and incident radiation.

In the similarity equation of equation (4), the ratio of each reflected and incident radiation,
And the ratio of each transmitted and incident radiation can be expressed by a more rigorous formula.

2l−h+−〆1←←1− The exponent of equation (5) can be similarly described in more detail. (n ground αny+βnp+l−α−β 1(−α, +βk p
rIn the above formula, α is the thickness refractive index of water, and β
is the thickness refractive index of the pulp, and (1-[α+β]] is the refractive index of the air.

By solving these equations, the water content, thickness, and basic type Q can be obtained.The basic equation that is the basis of the formula 1 will be described below.

Let A be the amplitude of the incident wave A in FIG. 1, which is a composite wave. Each component of the reflected wave group or the transmitted wave group AI, A2.・・・
...AN, Bl, B2. ......For BN, the variable part of the phase shift of the wave function is F[-1
differs from the preceding variable by the corresponding amount. This 111 difference is expressed as 4π δ−Rb cos θ′ λ.

where H is the thickness of the medium, λ is the wavelength in air, and N is the complex refractive index of the medium.

When the total reflected waves are superimposed, the amplitude of the reflected waves is expressed by the following equation:

The relationship between 〒 and R is as follows.

nu cos θ′ = π 婁n−jk F! sinθ' −sinθ− cosθ'=1 −5in2 θl Yo'N GO! i
θ' = n J k = (n - jK)2 = (N
-jK) 2- 5in2 θn 2- to 2-2jnk-
N2- is 2-2jNK-5in2 θ Equating the real part and mantissa part, n2- is 2=N2- is 2-5in2θ nk-NK-1-N2-n2 is 2 Therefore, N2- is 2- 5in2θ→ n'-n2[N2-X2-sin2θ]-2 to N2
-0.

Solving with the previous equation, we get and becomes.

Similarly, becomes.

The output R of the reflected wave is given by the following equation.

R,,,(r)Ir)*1-,a,(1),a,(
1) *Similarly, when all the transmissions are superimposed, the amplitude of the transmitted wave is given by:

,,,,AL)zut)*'a2ak[c2ak+lr14cm"ak-21
r12cos(2αn-?r2)] When the electroelectric pect is perpendicular to the incident plane (TE wave is 47 gigahertz) The ratio of the output of the reflected wave to the incident wave is calculated by the following equation.

In the preferred embodiment of the invention of Section 1)-+1-MeIE-@2, the medium is paper. This paper consists of a mixture of water, air, bulbs and fillers. The optical path can be modeled as the sum of the optical paths passing through the paper.

/=, Σ H4j−HN where L is the optical path, +9 is the thickness of the third paper, and N is the complex refractive index of the No.th paper. In this case, the total paper thickness is;

When K is the complex refractive index of paper, it is as follows: SHAKU H−H NU +H RYO +HFZ vw pp aa Here, W represents water, p represents a bulb, and a represents air.

However, the following conditions apply.

FJ-N-jK, F(-N -jy, .

v v ν'F(-N-
jK, Nu -N -jK.

pp paa H(N-jK)=H(N-jK) +w
wwH(N
−jK )+H(N −jK )p
p p a
a aHN-jHK-HN
+HN +vv pp HN -j[HK +HK +HK
] a' a v v
Since the real parts of p p a a are equal, NH−NH+HN +HH ww pp aa and .

The indices of air are N-1 and K-0.

a a now, Assuming that, N-αN +βN+ (1-(α+β)).

Here, α is the decimal part of the thickness of water, and β is the decimal part of the thickness of the valve.

A similar formula holds for the mantissa part of the exponent.

K −α K + β K + [1−(α
+ β ) K aw p However, K-0, = αK + βK.

av
The p water and bulb indices are experimentally obtained values, nw
, np, kw, kp are 94 GHz and T 47 GHz. From the equations - and -, the medium index can be replaced with the paper index.

N-αN +βN +1-α-3 w p K-αH+βK w p T In the formulas - and -, the three I, α, β, and H There are unknown quantities.

Operating at 29 different frequencies, we solve 49 equations for 3 unknowns (and the fractional part (thickness) of water α
, the decimal part β of the thickness of the bulb, and the thickness of the paper H.

The basis weight of paper is given by Bd-ρpHp+ραHα Bd-ρ, βH+ρ, (1-(α+β))H. However, ρ is the concentration of the bulb, and ρ is the concentration of a air (a very small value).

Also, the basic weight of water is expressed as B −p αH W
v and ρ is the concentration of water.

■ Calculating the basic weight of a dry object and a water-containing object determines the percentage of weight of water.

As shown in FIG. 2, the transmitters 12.14 each have a temperature sensor 3.15. Temperature sensor 3.1
5 generates a signal proportional to the temperature of each Gunn diode oscillator and is connected to a signal processor 32 to obtain a signal indicative of the incident radiation applied to the web 18. Therefore, the temperature sensor 3.15 is connected to the transmitter 12.
A different incident signal for each beam provided by 14 constitutes an incident signal generating means for generating an incident signal proportional to the energy incident on the web 18.

Of course, other configurations may be used as the means for supplying the incident signal. Signal processor 32 outputs signals indicative of the ratio of transmission to incidence and the ratio of reflection to incidence.

Another embodiment of signal processing by the computer 34 is shown in FIG. This flowchart is almost the same as FIG. 7, and only the different parts will be described.

At block 400, the value of the transmission sensor is read, and at block 401, a signal indicating the incident power on the 17 web 18 is read. The same processing as in FIG. 7 continues up to professional step 409, where the ratio of reflection to incidence (R/I) and the ratio of transmission to incidence (T/I) are calculated. Next, proceed to block 421 i:l: where water content, thickness, and basis weight are calculated. All other points are the same as the flowchart in FIG.

Note that this invention is not limited to the above-described embodiments, and may be modified without departing from the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a diagram showing transmission and reflection modes of a beam of coherent radiation incident on paper, FIG. 2 is a schematic block diagram of a preferred embodiment of the present invention, and FIG. 3 is another embodiment of the present invention. 4 is a perspective view of a detection array according to another embodiment of the present invention; FIG. 5 is a plan view of a reflective module and a transmitting module of the array of FIG. 4; and FIG. Schematic diagram showing the operation of the microwave lens in Figure 7.
The figure is a flowchart showing the computer processing shown in FIGS. 2 and 3, and FIG. 8 shows the incident signal, reflected signal,
Flowchart 1 shows the processing of the embodiment in which the basic weight is calculated from the transmission signal and the transmission signal. A, Al, A2. AN, Bl, B2... Ray, a...
・Incidence angle, 18...paper, 12.14...transmitter, 1
6... Transmission antenna, 20... Reflected signal receiving antenna, 22.24.28.30... Detector, 34... Computer, 36... Display device, 38... Reflection unit, 40... - Transmission unit, 44...Basic weight monitor, 46...Detection array, 50...Reflection module,
56...Reflection frame, 62...Transmission frame, 7
2... Cable, 74... Power module, 81.8
3... Beam, 90... Incident area, 94... Reflection beam splitter, 100... Lens, 102...
Transmission beam splitter, 106...antenna. Applicant's representative Patent attorney Takehiko Suzue Figure 1 (No change in content) No. 6 Figure 722ζ'' No. 31'1

Claims (1)

Claims: 1. radiating means for generating a plurality of beams of coherent electromagnetic radiation, each having a different frequency, and emitting said beam onto a paper-like object in an incident area; reflecting from said paper-like object; and a first signal generating means for generating different reflected and transmitted signals for each beam proportional to the intensity of each beam transmitted through the paper-like material; moisture and thickness signals calculated from the plurality of reflected and transmitted signals. 1. A device for detecting characteristics of paper-like materials, characterized in that the device is comprised of a processing means for outputting. 2. The apparatus for detecting characteristics of paper-like materials according to claim 1, wherein the beam is a standing wave. 3. The radiation means is composed of a plurality of radiation means, each of the radiation means emits a beam to a different incident area provided at a distance on the paper-like material, and the processing means is configured for each of the radiation means. Detecting characteristics of a paper-like material according to claim 2, wherein the paper-like material is outputted with different moisture and thickness signals, thereby outputting a spatial shape of moisture and thickness characteristics for the paper-like material. device to do. 4. The apparatus for detecting characteristics of paper-like materials according to claim 3, wherein the radiation means is comprised of means for generating microwave radiation. 5. Detecting the characteristics of the paper-like material according to claim 4, wherein the means for generating microwaves generates radiation having a wavelength longer than four times the thickness of the paper-like material. device to do. 6. A second generating means for generating a reference signal proportional to the basis weight at the reference position, and the processing means generates a spatial shape of the basis weight of the paper-like material calculated from the reference signal and the moisture and thickness signals. An apparatus for detecting characteristics of paper-like materials according to claim 2, characterized in that the apparatus generates a characteristic of a paper-like material. 7. A transmission antenna and a reflection receiving antenna provided at a stationary position on one side of the surface of the moving web of the paper-like material, and a transmission antenna and a reflection receiving antenna provided at a stationary position on the opposite side of the surface of the moving web of the paper-like material. 7. A device for detecting characteristics of paper-like materials according to claim 6, characterized in that the device comprises a transmission receiving antenna. 8. The apparatus for detecting characteristics of paper-like materials according to claim 6, wherein the second generating means comprises means for generating a beam of particles. 9. The apparatus for detecting characteristics of paper-like materials according to claim 8, wherein the second generating means comprises means for generating an electron beam. 10. The apparatus for detecting characteristics of paper-like materials according to claim 9, wherein the second generating means is constituted by a radiation source that generates beta rays. 11. The apparatus for detecting characteristics of paper-like materials according to claim 9, wherein the second generating means is constituted by an electron gun. 12. The reflected and transmitted signals are coherent and proportional to the intensity of each beam reflected from and transmitted through the paper material.
A device for detecting the characteristics of paper-like materials as described in Section 1. 13. The paper-like material according to claim 1, wherein the processing means comprises means for solving simultaneous equations having functions of water content, thickness, and complex refractive index of the paper-like material. A device that detects the characteristics of 14. Claim 4, wherein the processing means comprises means for solving a plurality of simultaneous equations having functions of the water content and thickness of the paper-like material and the complex refractive index of the beam. A device that detects the characteristics of the described paper-like materials. 15. A plurality of radiating means for generating coherent microwave electromagnetic radiation, each radiating means generating a plurality of beams having a different frequency, each said radiating means transmitting said plurality of correlated beams to said paper-like a plurality of radiation means for directing radiation into different incident areas spaced apart from each other; first signal generating means for generating different reflected and transmitted signals for each beam; second generating means for generating a reference signal proportional to the basis weight at the reference position; and the plurality of reflected and transmitted signals and the reference. and processing means for processing different water content signals and thickness signals of each of the radiation means calculated from the signals to generate spatial shapes of water content and thickness of the paper-like material. A device that detects the characteristics of types. 16. generating a plurality of beams of coherent electromagnetic radiation having different frequencies; directing the plurality of beams to an incident area of the paper-like material; each beam reflected from the paper-like material and the The method is characterized by comprising the steps of: generating different reflected and transmitted signals proportional to the amount of each beam transmitted through the paper-like material; and calculating water content and thickness from the reflected and transmitted signals. , a method for simultaneously detecting multiple features of paper-like materials. 17. generating a plurality of beams of coherent electromagnetic radiation, each beam of a group having a different frequency than the other beams of the group; directing; generating different reflected and transmitted signals of the beams that are proportional to the intensity of each beam reflected from the paper-like material and the intensity of each beam transmitted through the paper-like material; and the step of: calculating values representing water content and thickness signals of the paper-like material from the reflected signal and the transmitted signal in each incident region, and generating spatial shapes of the water content and thickness of the paper-like material; A method for simultaneously detecting multiple features of paper-like materials. 18. generating a reference signal proportional to the basis weight of the paper-like material in a region of the plurality of incident areas; calculating a plurality of basis weight values from the reference signal and values representative of the moisture content and the thickness; 18. A method for simultaneously detecting a plurality of characteristics of a paper-like material according to claim 17, further comprising the step of: 19. The step of generating the reference signal comprises the steps of directing an electron beam to be transmitted through the paper material and measuring the amount of electron beam energy transmitted through the paper material. characterized by
A method for simultaneously detecting a plurality of characteristics of a paper-like material according to claim 18. 20. Generating a plurality of dry basis weight signals from the basis weight value and the moisture content value. How to detect at the same time. 21. The step of generating a plurality of beams of electromagnetic radiation comprises the step of generating a plurality of microwave signals; How to detect features simultaneously. 22. Simultaneously detecting a plurality of characteristics of a paper-like object according to claim 17, wherein the step of generating the plurality of signals comprises a step of generating a plurality of laser signals. Method. 23. a first radiation source generating a first beam of coherent electromagnetic radiation; a second radiation source generating a second beam of coherent electromagnetic radiation having a different frequency than said first beam; a first focusing means for parallelizing the first and second beams and directing the first and second beams with respect to the paper to be analyzed; and a second focusing means for receiving a second beam, and said reflected first and second beams.
a reflection unit comprising first and second reflection detection means for generating first and second reflection signals in response to the intensity of the beam; The first and second parts are attached and pass through the paper-like material to be analyzed.
a transmission unit comprising first and second transmission detection means for generating first and second transmission signals, respectively, in response to the intensity of the paper; and a paper to process and analyze the reflected and transmitted signals. 1. A device for analyzing paper types, comprising means for outputting a signal representing characteristics of the type. 24. A beam combiner disposed below the radiation source for directing the first and second beams along a common path. A device that analyzes aspects. 25, the second focusing means is provided at the lower stage of the second focusing means to direct the reflected first and second beams to the first and second beams;
a reflective beam splitter that directs the transmitted first and second beams to the first and second transmission detection means; Claim 24, characterized in that:
A device that analyzes the paper-like materials described in Section 1. 26. Analyzing paper-like materials according to claim 25, wherein the reflection unit reflects at least one of the first and second beams from the radiation source to the beam combiner. Device. 27. The apparatus for analyzing paper-like materials according to claim 25, wherein the reflection unit reflects the first and second beams from the radiation source to the beam combiner. 28. The apparatus for analyzing paper-like materials according to claim 27, wherein the reflecting means is constituted by an off-axis parabolic mirror. 29. The first and second reflective focusing means each comprises a lens of dielectric material, and the first reflective focusing means lens has an output beam waist size different from the input beam waist size of the second reflective focusing means lens. Claim 25 characterized in that
A device that analyzes the paper-like materials described in Section 1. 30, the first reflective focus means lens is
30. An apparatus for analyzing paper materials according to claim 29, characterized in that the apparatus has an output beam waist size larger than an input beam waist size of the reflective focusing means lens. 31. The paper type according to claim 25, comprising a transmission module composed of a transmission mounting board and a pair of transmission units mounted on opposite sides of the transmission mounting board. A device that analyzes 32. The paper type according to claim 31, comprising a reflection module composed of a reflection mounting board and a pair of reflection units mounted on opposite sides of the reflection mounting board. A device that analyzes 33. a plurality of transmission modules; the same number of reflection modules as the transmission modules; means for connecting the transmission detection means and the reflection detection means to the processing means; a transmission frame supporting the transmission modules juxtaposed on the horizontal plane; a reflective frame supporting reflective modules juxtaposed to said horizontal plane; and defining an aperture extending parallel to said horizontal plane, said reflective frame being adapted to receive a moving web of paper being an object to be analyzed; 33. An apparatus for analyzing paper-like materials as claimed in claim 32, characterized in that it is comprised of a transparent frame and a means for supporting it one-to-one in the vertical direction. 34. Analyzing paper-like materials according to claim 33, wherein the transmission module is disposed above the elongated aperture, and the reflection module is disposed below the elongated aperture. Device. 35. Each of the reflection units includes a first modulator that performs a first modulation on the first beam, and a second modulator that performs a second modulation on the second beam. An apparatus for analyzing paper-like materials according to claim 33. 36. The apparatus for analyzing paper-like materials according to claim 35, wherein the first modulators of adjacent reflection units perform modulation of different frequencies. 37. The reflective frame is composed of a plurality of control devices,
36. The method of analyzing a paper type according to claim 35, wherein each of the control devices is detachably connected to the reflection unit, and the modulator determines a modulation frequency in response to the control device. device to do. 38. radiating means for generating a plurality of beams of coherent electromagnetic radiation, each having a different frequency, and emitting said beam onto a paper-like object in an incident area; reflecting from said paper-like object; first signal generating means for generating reflected and transmitted signals proportional to the intensity of each transmitted beam and different for each beam; a moisture signal, a thickness signal and a thickness signal calculated from the plurality of reflected signals, transmitted signals and incident signals; 1. A device for detecting characteristics of paper-like materials, comprising processing means for outputting a basic weight signal. 39. The apparatus for detecting characteristics of paper-like materials according to claim 38, wherein the beam is a standing wave. 40. The radiation means is composed of a plurality of radiation means, each radiation means emits a beam to a different incident area provided at a distance on the paper-like material, and the processing means outputs different moisture signals, thickness signals and basic weight signals, thereby determining moisture characteristics,
40. An apparatus for detecting characteristics of paper-like materials according to claim 39, characterized in that the device outputs spatial shapes of thickness characteristics and basic weight characteristics. 41. An apparatus for detecting characteristics of paper-like materials according to claim 40, wherein the radiation means comprises means for generating microwave radiation. 42. Detecting the characteristics of a paper-like material according to claim 41, wherein the means for generating microwaves generates radiation having a wavelength longer than four times the thickness of the paper-like material. device to do. 43. The reflected and transmitted signals are coherent and proportional to the intensity of each beam reflected from and transmitted through the paper material.
A device for detecting characteristics of paper-like materials according to item 8. 44. The paper-like material according to claim 38, wherein the processing means comprises means for solving simultaneous equations having functions of water content, thickness, and complex refractive index of the paper-like material. A device that detects the characteristics of 45. Claim 41, wherein the processing means comprises means for solving a plurality of simultaneous equations having functions of the water content and thickness of the paper-like material and the complex refractive index of the beam. A device that detects the characteristics of the described paper-like materials. 46. Apparatus for detecting paper-like features as claimed in claim 38, characterized in that the beams have different polarizations. 47. An apparatus for detecting characteristics of paper-like materials according to claim 46, wherein said radiation means generates a pair of orthogonally polarized beams. 48. generating a plurality of beams of coherent electromagnetic radiation having different frequencies; directing the plurality of beams to an incident area of the paper-like material; each beam reflected from the paper-like material and the generating different incident, reflected and transmitted signals proportional to the amount of each beam transmitted through the paper-like material; calculating moisture content, thickness and basis weight from the incident, reflected and transmitted signals; A method for simultaneously detecting multiple features of a paper-like material. 49. generating a plurality of beams of coherent electromagnetic radiation, each beam of a group having a different frequency than the other beams of the group; directing; and generating different incident, reflected and transmitted signals of the beams proportional to the intensity of each beam reflected from the sheet of paper and the intensity of each beam transmitted through the sheet of paper. ; and calculate values representing a water content signal, a thickness signal, and a basis weight signal of the paper-like material from the incident signal, reflected signal, and transmitted signal in each of the incident regions, and calculate the water content, thickness, and a step of generating a spatial shape of basis weight. 50. The step of generating a plurality of beams of electromagnetic radiation comprises the step of generating a plurality of microwave signals. How to detect features simultaneously. 51. Simultaneously detecting a plurality of characteristics of a paper-like object as set forth in claim 49, wherein the step of generating the plurality of signals comprises a step of generating a plurality of laser signals. Method. 52. a first radiation source generating a first beam of coherent electromagnetic radiation; a second radiation source generating a second beam of coherent electromagnetic radiation having a different frequency than said first beam; a first focusing means for parallelizing the first and second beams and directing the first and second beams with respect to the paper to be analyzed; and a second focusing means for receiving a second beam, and said reflected first and second beams.
a reflection unit comprising first and second reflection detection means for generating first and second reflection signals in response to the intensity of the beam; The first and second parts are attached and pass through the paper-like material to be analyzed.
a transmission unit comprising first and second transmission detection means for respectively generating first and second transmission signals in response to the intensity of the first and second transmission signals applied to the paper-like material;
means for generating first and second incident signals indicative of the intensity of the beam; and means for processing the incident, reflected and transmitted signals and outputting a signal representative of the characteristics of the paper material to be analyzed. A device for analyzing paper-like materials.