JP6926286B2 - Evaluation device - Google Patents

Description

The present invention relates to an evaluation device for evaluating the characteristics of a membranous body.

Evaluation devices for evaluating the characteristics of samples are widespread. As such an evaluation device, one that uses an electromagnetic wave is known because there is little damage even if the sample is irradiated.

Patent Document 1 describes an evaluation device of a method called terahertz time region spectroscopy (THz-TDS method). The evaluation device uses a terahertz wave which is an electromagnetic wave having a frequency of 0.1 THz to 10 THz and a wavelength of 300 μm to 3 mm. Since the terahertz wave belongs to the boundary region between light and radio waves, it has both the straightness of light and the transparency of radio waves.

The evaluation device described in Patent Document 1 includes a transmitting unit that emits an electromagnetic wave and a receiving unit that receives the electromagnetic wave. A sample to be measured is arranged between the transmitting unit and the receiving unit. When the electromagnetic wave transmitted by the transmitting unit irradiates the sample, a part of the electromagnetic wave is absorbed by the sample and the other part transmits the sample. The evaluation device is based on the difference between the current waveform acquired by the receiving unit receiving the other part of the electromagnetic wave and the current waveform acquired by the receiving unit receiving the electromagnetic wave when the sample is not arranged. Evaluate the characteristics of the sample.

JP-A-2002-277394

By the way, the degree of absorption of electromagnetic waves by a sample depends on the distance through which the electromagnetic waves pass through the sample and the absorption coefficient of the sample. When the distance that the electromagnetic wave passes through the sample is small, the electromagnetic wave absorbed by the sample decreases. In this case, the difference between the two current waveforms described above becomes small.

Therefore, in a sample having a small thickness such as a film-like body, the transmission distance of electromagnetic waves is small, so that the difference between the two current waveforms described above is also small. Therefore, the apparatus described in Patent Document 1 has a problem that the characteristics of the film-like body cannot be evaluated accurately.

There is also a need to evaluate the characteristics of the molded product using the above-mentioned evaluation device before shipping. However, there is a problem that it is troublesome to set the film-like body in the evaluation device.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an evaluation device capable of evaluating the characteristics of a film-like body with high accuracy while transporting the film-like body.

The present invention is an evaluation device for evaluating the characteristics of a film-like body, in which the film-like body is supported by an outer peripheral surface, and a roller that conveys the film-like body by rotating around a rotation axis and electromagnetic waves are transmitted. A waveguide member that is arranged between a transmitting unit that transmits, a receiving unit that receives an electromagnetic wave transmitted by the transmitting unit, and the transmitting unit and the receiving unit, and guides the electromagnetic wave transmitted by the transmitting unit to the receiving unit side, and a receiving unit. It is provided with a calculation unit for deriving the characteristics of the film-like body by performing a predetermined calculation based on the electromagnetic wave received by. The waveguide member has a reflective surface that faces the outer peripheral surface of the roller with a gap and forms a waveguide with the outer peripheral surface. The reflecting surface is configured to guide the electromagnetic wave transmitted by the transmitting unit to the receiving unit while reflecting it between the electromagnetic wave and the outer peripheral surface of the roller.

According to the above configuration, the film-like body is supported by the outer peripheral surface of the roller and is conveyed by the rotation of the roller. The present invention evaluates the characteristics of the film-like body during transportation in this way. Therefore, for example, when the molded film-like body is conveyed from the molding machine by a roller, the characteristics of the film-like body can be evaluated. Therefore, it is possible to evaluate the characteristics of the membranous body with little effort.

Further, according to the above configuration, the electromagnetic wave emitted by the transmitting unit is guided to the receiving unit while being reflected between the outer peripheral surface of the roller and the reflecting surface of the waveguide member. Therefore, the electromagnetic wave is transmitted through the film-like body a plurality of times. As a result, it becomes possible to increase the transmission distance of electromagnetic waves in the film-like body and accurately evaluate the characteristics of the film-like body.

According to the present invention, it is possible to provide an evaluation device capable of evaluating the characteristics of a film-like body with high accuracy while transporting the film-like body.

It is a schematic diagram which shows the principle model. It is a graph which shows the current waveform acquired by the arithmetic unit of FIG. It is a front view which shows the waveguide member of FIG. It is a perspective view which shows the waveguide member of FIG. It is an enlarged view which shows the waveguide member of FIG. It is an enlarged view which shows the waveguide member of FIG. It is an enlarged view which shows the waveguide member of FIG. It is a perspective view which shows the evaluation apparatus which concerns on 1st Embodiment. It is a front view which shows the evaluation apparatus of FIG. It is a perspective view which shows the evaluation apparatus which concerns on the modification of 1st Embodiment. It is a perspective view which shows the evaluation apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows the XII-XII cross section of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components are designated by the same reference numerals as much as possible in each drawing, and duplicate description is omitted.

[Principle model]
First, the outline of the principle model 1 of the evaluation device will be described with reference to FIGS. 1 and 2. The principle model 1 is an apparatus for evaluating the optical characteristics (for example, absorption rate, refractive index, transmittance, etc.) of the film-like body M using terahertz time region spectroscopy. The film-like body M is an object whose thickness dimension is smaller than other dimensions. Examples of the film-like body M that can be evaluated include cotton fabrics, cupra fabrics, resin films, and the like. As shown in FIG. 1, the principle model 1 includes a transmitting unit 2, a receiving unit 3, a waveguide member 4, and a calculation unit 7.

The transmitting unit 2 is a device that transmits an electromagnetic wave to an external space. Specifically, the transmitting unit 2 generates a terahertz wave which is an electromagnetic wave having a frequency of 0.1 THz to 10 THz and a wavelength of 300 μm to 3 mm. The transmitting unit 2 has a mechanism capable of transmitting a terahertz wave, such as a femtosecond laser, a photoconducting antenna, a terahertz transmitting resonance tunnel diode (RTD), and a terahertz quantum cascade laser. FIG. 1 simplifies these and illustrates the transmitting unit 2 as one unit. The transmitting unit 2 emits an electromagnetic wave based on a control signal received from a control device (not shown).

The receiving unit 3 is a device that receives the electromagnetic wave transmitted by the transmitting unit 2. The receiving unit 3 is arranged at a distance from the transmitting unit 2. The receiving unit 3 has a plurality of members such as a light conductive element. FIG. 2 simplifies these and illustrates the receiving unit 3 as one unit. The receiving unit 3 can receive the electromagnetic wave transmitted by the transmitting unit 2 and detect the electric field strength of the electromagnetic wave as a current.

The waveguide member 4 is a member arranged between the transmitting unit 2 and the receiving unit 3. The waveguide member 4 has a waveguide 40 inside. The end of the waveguide 40 is open. Specifically, the waveguide member 4 has waveguide plates 5 and 6 facing each other with a gap between them, and the gap corresponds to the waveguide 40. The film-like body M is arranged in a part of the waveguide 40. As will be described later, the electromagnetic wave transmitted by the transmitting unit 2 is guided to the receiving unit 3 by passing through the waveguide 40.

In order to facilitate understanding, as shown in FIG. 1, the orthogonal coordinates in which the directions in which the waveguide plates 5 and 6 face each other are the Z direction and the directions orthogonal to the Z direction are the X direction and the Y direction are set. It will be described using. Also in FIGS. 3 and 3 and later, the coordinates corresponding to the orthogonal coordinates are shown.

The calculation unit 7 is a device for deriving the characteristics of the film-like body M. The arithmetic unit 7 is connected to at least the receiving unit 3. The calculation unit 7 derives the characteristics of the film-like body M by performing a predetermined calculation based on the current detected by the reception unit 3.

The calculation unit 7 acquires the current waveform shown in FIG. 2 from the reception unit 3. FIG. 2 shows a change in the current detected by the receiving unit 3 after the electromagnetic wave is transmitted from the transmitting unit 2. The waveform of the current Er detected by the receiving unit 3 when the film-like body M is not arranged on the waveguide 40 is shown by a solid line. On the other hand, the waveform of the current Em detected by the receiving unit 3 when the film-like body M is arranged on the waveguide 40 is shown by a broken line. The waveforms of the current Er and the current Em have a peak at the timing when the electromagnetic wave is received by the receiving unit 3.

When the film-like body M is not arranged in the waveguide 40, the electromagnetic wave transmitted by the transmitting unit 2 reaches the receiving unit 3 with almost no absorption in the waveguide 40. In this case, the peak of the waveform of the current Er appears clearly. The waveform of such a current Er is acquired prior to the evaluation of the film-like body M.

On the other hand, when the film-like body M is arranged in the waveguide 40, a part of the electromagnetic wave transmitted by the transmitting unit 2 is absorbed by the film-like body M in the waveguide 40. The other part of the electromagnetic wave passes through the film-like body M, passes through the waveguide 40, and reaches the transmitting part 2. That is, the waveform of the current Em shows that of the electromagnetic wave after transmission including multiple reflections. Therefore, the peak of the waveform of the current Em is smaller than that of the waveform of the current Er. Further, the peak of the waveform of the current Em appears slightly later than the timing at which the peak of the current Er appears.

The calculation unit 7 performs predetermined processing on each of the waveforms of the currents Er and Em. Specifically, the calculation unit 7 calculates the complex Fourier components of the waveforms of the currents Er and Em, and calculates the ratio between the two. The ratio of the two corresponds to the complex amplitude transmittance and is expressed as a function of the complex refractive index. Therefore, the calculation unit 7 can derive the complex refractive index, which is one of the optical characteristics of the film-like body M, based on the complex amplitude transmittance obtained in advance in the experiment.

In the principle model 1 configured as described above, in order to evaluate the characteristics of the film-like body M with high accuracy, the difference between the waveform of the current Er and the waveform of the current Em must be significant. In other words, it is necessary to configure the principle model 1 so that the difference between the waveforms of the currents Er and Em becomes remarkable depending on the presence or absence of the film-like body M in the waveguide 40.

Therefore, in the principle model 1, the configuration of the waveguide member 4 is devised in order to make the difference between the waveforms of the currents Er and Em remarkable. Next, the configuration of the waveguide member 4 will be described with reference to FIGS. 3 to 7.

As shown in FIGS. 3 and 4, the waveguide plates 5 and 6 have a plate shape in which the X-axis direction is the longitudinal direction and the Z-axis direction is the thickness direction. The waveguides 5 and 6 are made of aluminum. The dimensions Lx of the waveguide plates 5 and 6 in the X-axis direction are about 90 mm. As shown in FIG. 3, the waveguides 5 and 6 have reflecting surfaces 50 and 60 on one side surface thereof.

The reflective surfaces 50 and 60 are polished to be smooth surfaces with few irregularities. As a result, as will be described later, scattering when electromagnetic waves are reflected on the reflecting surfaces 50 and 60 is suppressed. The reflecting surfaces 50 and 60 have inlet-side tapered portions 51 and 61, flat portions 52 and 62, and outlet-side tapered portions 53 and 63.

The flat portions 52 and 62 are flat surfaces located at the center of the reflecting surfaces 50 and 60 in the X-axis direction. The dimensions Lx1 of the flat portions 52 and 62 in the X-axis direction are about 30 mm. The waveguide plates 5 and 6 are arranged so that the flat portions 52 and 62 are parallel to each other with a gap in the Z-axis direction. The dimension d of the gap in the Z-axis direction is set to be equal to or lower than the wavelength of the electromagnetic wave transmitted by the transmitting unit 2 (for example, 200 μm). The portion of the waveguide 40 formed between the flat portion 52 and the flat portion 62 is referred to as a film-like body arrangement portion 42. For the sake of understanding the explanation, the waveguide 40 is shown extremely large in FIGS. 3 to 7.

The film-like body M is arranged in the film-like body arrangement portion 42 so that its thickness direction is not orthogonal to the Z direction. Specifically, the film-like body M is arranged in the film-like body arrangement portion 42 so that its thickness direction coincides with the Z direction and extends along the flat portions 52 and 62. Both ends of the film-like body M in the Y-axis direction are fixed by jigs (not shown) so as not to come into contact with the flat portions 52 and 62.

The inlet-side tapered portions 51 and 61 are located closer to the transmitting portion 2 (not shown in FIG. 3) than the flat portions 52 and 62, and are surfaces continuous with the flat portions 52 and 62. The inlet-side tapered portions 51 and 61 are curved so as to project toward the waveguide 40. The portion of the waveguide 40 formed between the inlet side tapered portion 51 and the inlet side tapered portion 61 is referred to as an inlet portion 41. In the inlet portion 41, the inlet-side tapered portions 51, 61 are formed so as to gradually approach each other toward the X-axis direction. In other words, the inlet portion 41 is formed so that its width gradually decreases toward the X-axis direction.

The outlet-side tapered portions 53 and 63 are located closer to the receiving portion 3 (not shown in FIG. 3) than the flat portions 52 and 62, and are surfaces continuous with the flat portions 52 and 62. The outlet-side tapered portions 53 and 63 are curved so as to project toward the waveguide 40. Of the waveguide 40, a portion formed between the outlet side tapered portion 53 and the outlet side tapered portion 63 is referred to as an outlet portion 43. In the outlet portion 43, the outlet-side tapered portions 53 and 63 are formed so as to gradually separate from each other toward the X-axis direction. In other words, the outlet portion 43 is formed so that its width gradually increases toward the X-axis direction.

As shown in FIG. 5, the electromagnetic wave transmitted by the transmitting portion 2 (not shown in FIG. 5) first enters the inlet portion 41 from the end portion of the waveguide 40 in the −X direction. FIG. 5 schematically shows the traveling direction of the electromagnetic wave by the arrow A1. As shown by the arrow A1, the electromagnetic wave reciprocates in the Z direction by being repeatedly reflected by the inlet side tapered portions 51 and 61.

Further, as described above, the inlet side tapered portions 51 and 61 are curved so as to project toward the waveguide 40. Therefore, the inlet side tapered portions 51 and 61 reflect the electromagnetic wave so as to direct the X direction. Further, since the width of the inlet portion 41 gradually decreases toward the X-axis direction, the moving distance of the electromagnetic wave in the Z direction gradually decreases. As a result, the electromagnetic wave travels toward the film-like body arrangement portion 42 while converging.

The electromagnetic wave that has passed through the inlet portion 41 then enters the membrane-like body arrangement portion 42 as shown in FIG. As described above, the dimension d of the film-like body arrangement portion 42 in the Z-axis direction is smaller than the wavelength of the electromagnetic wave. In general, electromagnetic waves are difficult to pass through gaps whose dimensions are smaller than wavelength due to their diffraction limits.

In the principle model 1, the flat portions 52 and 62 are formed of aluminum, which is a metal material. When the electromagnetic wave that has entered the film-like body arrangement portion 42 travels in the vicinity of the flat portions 52 and 62, among the components of the electric field of the electromagnetic wave, the component parallel to the surface is shielded by free electrons in the metal and does not exist. , The boundary condition that only the components perpendicular to the surface are present is satisfied. Even when the dimension d of the film-like body arrangement portion 42 is set to be equal to or less than the diffraction limit of the electromagnetic wave, this boundary condition is satisfied, and the electromagnetic wave can travel while being reflected by the flat portions 52 and 62.

As shown by the arrow A2, the electromagnetic wave is repeatedly reflected by the flat portions 52 and 62, and travels in the film-like body arrangement portion 42 while reciprocating in the Z direction. Therefore, the electromagnetic wave repeatedly transmits the film-like body M arranged in the film-like body arrangement portion 42 in the thickness direction thereof. Specifically, a part of the electromagnetic wave that has reached the film-like body M is absorbed by the film-like body M, and the other part passes through the film-like body M.

The electromagnetic wave that has passed through the membranous body arrangement portion 42 then enters the outlet portion 43 as shown in FIG. As shown by the arrow A3, the electromagnetic wave reciprocates in the Z direction by being repeatedly reflected at the outlet side tapered portions 53 and 63.

Generally, when an apex angle is formed at the end of a waveguide, electromagnetic wave diffraction occurs at the apex angle. As a result, electromagnetic waves are diffused from the end of the waveguide, and the electromagnetic waves that can be received by the receiving unit 3 are reduced.

In the principle model 1, as described above, the outlet-side tapered portions 53 and 63 are curved so as to project toward the waveguide 40. As a result, the diffusion of electromagnetic waves at the end of the waveguide 40 is suppressed. The electromagnetic wave that has passed through the outlet unit 43 in this way is received by the receiving unit 3.

According to the principle model 1 configured as described above, the electromagnetic wave emitted by the transmitting unit 2 is guided to the receiving unit 3 while being reflected between the pair of reflecting surfaces 50 and 60. The film-like body M is arranged so that its thickness direction is not orthogonal to the direction in which the reflecting surfaces 50 and 60 face each other. Therefore, the electromagnetic wave is transmitted through the film-like body M a plurality of times in the thickness direction thereof. As a result, it becomes possible to increase the transmission distance of electromagnetic waves in the film-like body M and accurately evaluate the characteristics of the film-like body M.

By the way, the smaller the dimension d of the film-like body arrangement portion 42, the more the electromagnetic wave can be converged on the film-like body arrangement portion 42, and the evaluation accuracy can be improved. However, when the dimension d between the reflecting surfaces 50 and 60 is less than the wavelength of the electromagnetic wave, the electromagnetic wave cannot pass through the film-like body arrangement portion 42 due to the diffraction limit.

Therefore, in the principle model 1, the reflecting surfaces 50 and 60 are formed of a metal material. According to this configuration, even when the dimension d between the reflecting surfaces 50 and 60 is smaller than the wavelength of the electromagnetic wave, the electromagnetic wave is a film-like body due to the interaction with the free electrons existing on the reflecting surfaces 50 and 60. It becomes possible to pass through the arrangement portion 42. As a result, the electromagnetic wave can be converged on the film-like body arrangement portion 42, and the evaluation accuracy of the characteristic can be improved. This configuration is particularly suitable when the electromagnetic wave transmitted by the transmitting unit 2 is a terahertz wave having a longer wavelength than other electromagnetic waves.

Further, the reflecting surfaces 50 and 60 have inlet-side tapered portions 51 and 61 that gradually reduce the width of the waveguide 40 from the transmitting portion 2 side toward the film-like body arranging portion 42 side. According to this configuration, the electromagnetic wave transmitted from the transmitting unit 2 can be guided to the film-like body arranging unit 42 while being converged by the inlet-side tapered portions 51 and 61. As a result, it becomes possible to further improve the evaluation accuracy of the characteristics.

Further, the inlet side tapered portions 51 and 61 are curved so as to project toward the waveguide 40. According to this configuration, the electromagnetic wave transmitted from the transmitting unit 2 can be directed more toward the film-like body arranging unit 42. As a result, the electromagnetic waves can be converged with high efficiency, and the evaluation accuracy of the characteristics can be further improved.

Further, the reflecting surfaces 50 and 60 have outlet-side tapered portions 53 and 63 that gradually increase the width of the waveguide 40 from the film-like body arranging portion 42 side toward the receiving portion 3 side. According to this configuration, the diffraction of the electromagnetic wave at the end of the waveguide 40 can be suppressed, and the electromagnetic wave that has passed through the film-like body arrangement unit 42 can be more reliably received by the receiving unit 3.

Next, an evaluation device according to an embodiment to which the principle model 1 is applied will be described. The evaluation device described below is applied to the manufacturing process of a film-like body. Specifically, the evaluation device is applied to a step of transporting a film-like body from a molding machine (not shown), and evaluates the characteristics of the film-like body during transportation.

[First Embodiment]
The evaluation device 1A according to the first embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a perspective view showing the evaluation device 1A. FIG. 9 is a front view showing the evaluation device 1A, and shows an enlarged view of the vicinity of the waveguide plate 5A, which will be described later. Among the configurations of the evaluation device 1A, those having the same functions as the configuration of the principle model 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The evaluation device 1A evaluates the optical characteristics of the film-like body M1 molded by a molding machine (not shown), and detects defects occurring in the film-like body M1 based on the optical characteristics. The film-like body M1 has a band shape and is molded by cross-linking the polymer with a molding machine. The evaluation device 1A detects the presence or absence of a site in which the polymer is not properly crosslinked in the film-like body M1.

The evaluation device 1A is incorporated in a transfer device that conveys the film-like body M1. The evaluation device 1A includes a transmitting unit 2, a receiving unit 3, a waveguide 5A, a calculation unit 7 (see FIG. 8), a roller 8, an inlet side lens 91, and an outlet side lens 92.

The roller 8 is a device that conveys the film-like body M1. The roller 8 has a substantially cylindrical shape and can rotate about the rotation shaft 81 shown in FIG. The film-like body M1 is arranged so that the direction in which the rotation shaft 81 extends and the width direction coincide with each other, and one side surface thereof abuts on the outer peripheral surface 831 of the roller 8 and is supported.

When an actuator (not shown) is driven, the roller 8 receives a force from the actuator and rotates in the direction indicated by the arrow R1. Along with this rotation, the film-like body M1 advances toward the outer peripheral surface 831 of the roller 8 as shown by the arrow A4. The membranous body M1 folds back along the outer peripheral surface 831 and proceeds in the direction indicated by the arrow A5.

As shown in FIG. 9, the roller 8 has a skeleton portion 82 and a metal film 83. The skeleton portion 82 is provided in the central portion of the roller 8 and forms the skeleton of the roller 8 having a substantially cylindrical shape. The metal film 83 is provided on the outer peripheral portion of the skeleton portion 82, and is made of aluminum. The surface of the metal film 83, which is also the outer peripheral surface 831 of the roller 8, is polished to be a smooth surface with few irregularities. As a result, as will be described later, scattering when the electromagnetic wave is reflected on the outer peripheral surface 831 is suppressed.

The waveguide plate 5A is a member having a plate shape. The waveguide 5A is made of aluminum and is curved along a part of the outer peripheral surface 831 of the roller 8. Further, as shown in FIG. 9, the waveguide 5A faces the outer peripheral surface 831 with a gap of dimension d. The gap corresponds to the waveguide 40A. The film-like body M1 is arranged in this waveguide 40A. The transmitting unit 2 and the receiving unit 3 are arranged so as to face each other with the waveguide 40A in the circumferential direction of the roller 8. The waveguide plate 5A, together with the metal film 83 of the roller 8, exhibits the same function as the waveguide member 4 of the principle model 1 described above.

As shown in FIG. 9, the waveguide 5A has a reflecting surface 50A on one side surface thereof. The reflective surface 50A is polished to be a smooth surface with few irregularities. Further, the reflecting surface 50A has an inlet side tapered portion 51A, a central portion 52A, and an outlet side tapered portion 53A.

The inlet side tapered portion 51A is located on the transmitting portion 2 side with respect to the central portion 52A and is a surface continuous with the central portion 52A. The inlet side tapered portion 51A is curved so as to project toward the outer peripheral surface 831 of the roller 8. Of the waveguide 40A, the portion formed between the inlet side tapered portion 51A and the outer peripheral surface 831 is referred to as an inlet portion 41A. In the inlet portion 41A, the inlet side tapered portion 51A is formed so as to gradually approach the outer peripheral surface 831 toward the receiving portion 3 side. In other words, the inlet portion 41A is formed so that its width gradually decreases toward the receiving portion 3 side.

The central portion 52A is a surface located at the central portion of the waveguide 5A. The central portion 52A is arranged so as to form a gap having a dimension d from the outer peripheral surface 831 of the roller 8. The dimension d is smaller than the wavelength of the electromagnetic wave transmitted by the transmitting unit 2. Of the waveguide 40A, the portion formed between the central portion 52A and the outer peripheral surface 831 is referred to as the central portion 42A.

The outlet-side tapered portion 53A is located on the receiving portion 3 side of the central portion 52A and is a surface continuous with the central portion 52A. The outlet-side tapered portion 53A is curved so as to project toward the outer peripheral surface 831 of the roller 8. Of the waveguide 40A, the portion formed between the outlet side tapered portion 53A and the outer peripheral surface 831 is referred to as an outlet portion 43A. In the outlet portion 43A, the outlet side tapered portion 53A is formed so as to gradually approach the outer peripheral surface 831 toward the receiving portion 3 side. In other words, the outlet portion 43 is formed so that its width gradually increases toward the receiving portion 3 side.

The inlet-side lens 91 and the exit-side lens 92 are elements that refract electromagnetic waves. The inlet side lens 91 and the outlet side lens 92 converge or diverge the electromagnetic waves incident from one side surface and emit them from the other side surface. The inlet side lens 91 is arranged between the transmitting portion 2 and the waveguide 40A. The entrance side lens 91 is arranged so that its plane faces the transmitting portion 2. The outlet side lens 92 is arranged between the waveguide 40A and the receiving unit 3. The outlet side lens 92 is arranged so that its plane faces the receiving unit 3.

As shown in FIG. 9, the electromagnetic wave transmitted by the transmitting unit 2 first incidents on one side surface of the inlet side lens 91. By passing through the inlet side lens 91, the electromagnetic wave is diverged in the direction in which the rotation shaft 81 of the roller 8 extends, and is emitted from the other side surface. As a result, the electromagnetic wave is emitted over a wide range in the width direction of the film-like body M1.

The electromagnetic wave transmitted through the entrance side lens 91 enters the entrance portion 41A of the waveguide 40A. FIG. 9 schematically shows the traveling direction of the electromagnetic wave by the arrow A4. As shown by the arrow A4, the electromagnetic wave reciprocates in the radial direction of the roller 8 by being repeatedly reflected by the inlet side tapered portion 51A and the outer peripheral surface 831 of the roller 8.

Further, as described above, the inlet side tapered portion 51A is curved so as to project toward the waveguide 40A. Therefore, the inlet side tapered portion 51A reflects the electromagnetic wave so as to direct the receiving portion 3. Further, since the width of the inlet portion 41A gradually decreases toward the receiving portion 3, the moving distance of the electromagnetic wave in the radial direction of the roller 8 gradually decreases. As a result, the electromagnetic wave travels toward the central portion 42A of the waveguide 40A while converging.

The electromagnetic wave reciprocates in the radial direction of the roller 8 and repeatedly transmits the film-like body M1 supported by the outer peripheral surface 831 of the roller 8 in the thickness direction thereof. Specifically, a part of the electromagnetic wave that has reached the film-like body M is absorbed by the film-like body M, and the other part passes through the film-like body M.

The electromagnetic wave that has passed through the inlet portion 41A then enters the central portion 42A. As described above, the dimension d of the central portion 42A is smaller than the wavelength of the electromagnetic wave. However, due to the above-mentioned interaction between the electromagnetic wave and the free electron, the electromagnetic wave can travel in the central portion 42A.

The electromagnetic wave that has passed through the central portion 42A then enters the exit portion 43A. As shown by the arrow A4, the electromagnetic wave reciprocates in the radial direction of the roller 8 by being repeatedly reflected by the outlet side tapered portion 53A and the outer peripheral surface 831 of the roller 8.

As described above, the outlet-side tapered portion 53A is curved so as to project toward the outer peripheral surface 831 of the roller 8. As a result, the electromagnetic wave passes through the outlet portion 43A without being diffused at the end of the waveguide 40A.

The electromagnetic wave that has passed through the outlet portion 43A is then incident on one side surface of the outlet side lens 92. The electromagnetic wave passes through the outlet side lens 92, converges in the direction in which the rotation shaft 81 of the roller 8 extends, and is emitted from another side surface. The electromagnetic wave is received by the receiving unit 3 arranged so as to face the other side surface of the outlet side lens 92.

The calculation unit 7 (see FIG. 8) acquires a current waveform from the reception unit 3. The calculation unit 7 evaluates the optical characteristics of the film-like body M1 based on the difference between the current waveform when the film-like body M1 is arranged on the waveguide 40A and the current waveform when the film-like body M1 is not arranged. .. Based on the optical properties, it is possible to detect that the film-like body M1 has a site where the polymer is not properly crosslinked.

According to the configuration of the evaluation device 1A, the film-like body M1 is supported by the outer peripheral surface 831 of the roller 8 and is conveyed by the rotation of the roller 8. The evaluation device 1A evaluates the characteristics of the film-like body M1 during transportation in this way. Therefore, for example, when the molded film-like body M1 is conveyed from the molding machine by the roller 8, the characteristics of the film-like body M1 can be evaluated. Therefore, it is possible to evaluate the characteristics of the membranous body M1 with less effort.

Further, according to the configuration of the evaluation device 1A, the electromagnetic wave emitted by the transmitting unit 2 is guided to the receiving unit 3 while being reflected between the outer peripheral surface 831 of the roller 8 and the reflecting surface 50A of the waveguide 5A. Therefore, the electromagnetic wave is transmitted through the film-like body M1 a plurality of times in the thickness direction. As a result, the transmission distance of electromagnetic waves in the film-like body M1 can be increased, and the characteristics of the film-like body M1 can be evaluated with high accuracy.

Further, the outer peripheral surface 831 of the roller 8 and the reflective surface 50 of the waveguide 5A are formed of a metal material. According to this configuration, even when the dimension d between the reflecting surface 50A and the outer peripheral surface 831 of the roller 8 is smaller than the wavelength of the electromagnetic wave, the electromagnetic wave is free electrons existing on the reflecting surface 50 and the outer peripheral surface 831. By interacting with, it becomes possible to pass through the waveguide 40A. As a result, it becomes possible to converge the electromagnetic wave on the waveguide 40A and improve the evaluation accuracy of the characteristics. This configuration is particularly suitable when the electromagnetic wave transmitted by the transmitting unit 2 is a terahertz wave having a longer wavelength than other electromagnetic waves.

Further, the reflecting surface 50A has an inlet-side tapered portion 51A that gradually reduces the width of the waveguide 40A from the transmitting portion 2 side to the receiving portion 3 side. According to this configuration, the electromagnetic wave transmitted from the transmitting unit 2 can be guided to the receiving unit 3 side while being converged by the inlet side tapered portion 51A. As a result, it becomes possible to further improve the evaluation accuracy of the characteristics.

Further, the inlet side tapered portion 51A is curved so as to project toward the outer peripheral surface 831 side. According to this configuration, the electromagnetic wave transmitted from the transmitting unit 2 can be directed toward the receiving unit 3. As a result, the electromagnetic waves can be converged with high efficiency, and the evaluation accuracy of the characteristics can be further improved.

Further, the reflecting surface 50A has an outlet-side tapered portion 53A that gradually increases the width of the waveguide 40A from the transmitting portion 2 side to the receiving portion 3 side. According to this configuration, the diffraction of the electromagnetic wave at the end of the waveguide 40A can be suppressed, and the electromagnetic wave that has passed through the waveguide 40A can be more reliably received by the receiving unit 3.

Further, the evaluation device 1A includes an inlet-side lens 91 that diverges the electromagnetic wave transmitted by the transmitting unit 2 between the transmitting unit 2 and the waveguide 40A. According to this configuration, by diverging the electromagnetic wave, the electromagnetic wave can be transmitted over a wide range of the film-like body M1. Therefore, it becomes possible to evaluate the characteristics of the membranous body M1 over a wide range.

Further, the evaluation device 1A includes an outlet side lens 92 that converges the electromagnetic wave that has passed through the waveguide 40A between the waveguide 40A and the receiving unit 3. According to this configuration, the electromagnetic wave that is diverged by passing through the inlet side lens 91 and has passed through the waveguide 40A can be converged toward the receiving unit 3. This makes it possible for the receiving unit 3 to reliably receive the electromagnetic wave while transmitting the electromagnetic wave over a wide range of the film-like body M1.

[Modification example]
The evaluation device 1B according to the modified example of the first embodiment will be described with reference to FIG. FIG. 10 is a perspective view showing the evaluation device 1B. Among the configurations of the evaluation device 1B, those having the same functions as the configurations of the principle model 1 and the evaluation device 1A are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The evaluation device 1B includes waveguide plates 5B1 and 5B2. The waveguides 5B1 and 5B2 are made of aluminum and are curved along a part of the outer peripheral surface 831 of the roller 8. The waveguides 5B1 and 5B2 are independent of each other and are arranged so as to be adjacent to each other in the direction in which the rotation shaft 81 extends. The waveguide plates 5B1 and 5B2 face each other with a gap of dimension d from the outer peripheral surface 831. The gap becomes a waveguide independent of each other. The membranous body M1 is arranged so as to cross each waveguide.

Further, the evaluation device 1B includes two transmitting units 2 and two receiving units 3 (in FIG. 10, the illustration of one transmitting unit 2 is omitted). The transmitting unit 2 and the receiving unit 3 are arranged so as to face each other with each waveguide sandwiched in the circumferential direction of the roller 8. The waveguide plates 5B1 and 5B2, together with the metal film 83 of the roller 8, exhibit the same functions as the waveguide member 4 of the principle model 1 described above.

Further, an inlet side lens 911, 912 and an outlet side lens 921, 922 are arranged at the end of each waveguide formed by the waveguide plates 5B1 and 5B2. Specifically, the inlet side lens 911 and the outlet side lens 921 are arranged to face each other across the waveguide formed by the waveguide 5B1, and the inlet side lens 912 and the outlet side sandwich the waveguide formed by the waveguide 5B2. The lens 922 and the lens 922 are arranged to face each other.

According to the configuration of the evaluation device 1B, the electromagnetic waves emitted by the two transmitting units 2 travel while reflecting different waveguides, and are received by the receiving units 3 that are different from each other. Therefore, the characteristics of the film-like body M1 can be evaluated for each portion different in the direction in which the rotation shaft 81 extends. Therefore, when detecting a defect occurring in the film-like body M1, it becomes possible to specify the location where the defect occurs in more detail.

[Second Embodiment]
The evaluation device 1C according to the second embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 is a perspective view showing the evaluation device 1C. FIG. 12 is a cross-sectional view showing a cross section of XII-XII of FIG. 11, and shows an enlarged view of the vicinity of the waveguide 5C. Among the configurations of the evaluation device 1C, those having the same functions as the configurations of the principle model 1 and the evaluation devices 1A and 1B are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In the evaluation device 1C, the roller 8C has portions whose radius gradually changes at both ends in the direction in which the rotating shaft 81 extends. Specifically, the outer peripheral surface 831C of the roller 8C has an inlet tapered portion 61C and an outlet side tapered portion 63C, and the roller 8C has a radius thereof of the inlet tapered portion 61C and the outlet side tapered portion 63C. It is configured to change in. The inlet tapered portion 61C and the outlet side tapered portion 63C are curved so as to project toward the waveguide 40C, which will be described later.

Further, the transmitting unit 2 and the receiving unit 3 are arranged apart from each other in the direction in which the rotating shaft 81 of the roller 8C extends. Further, as shown in FIG. 12, the waveguide 5C faces the outer peripheral surface 831C of the roller 8C with a gap of dimension d. The gap corresponds to the waveguide 40C, and is formed so that the direction in which the rotation shaft 81 extends is the longitudinal direction. The transmitting unit 2 and the receiving unit 3 are arranged so as to face each other with the waveguide 40C in the direction. The waveguide plate 5C, together with the metal film 83C of the roller 8C, exhibits the same function as the waveguide member 4 of the principle model 1 described above.

As shown in FIG. 12, the waveguide 5C has a reflecting surface 50C on one side surface thereof. Further, the reflecting surface 50C has an inlet side tapered portion 51C, a central portion 52C, and an outlet side tapered portion 53C. The inlet-side tapered portion 51C, the central portion 52C, and the outlet-side tapered portion 53C function in the same manner as the inlet-side tapered portion 51A, the central portion 52A, and the outlet-side tapered portion 53A according to the first embodiment. That is, the inlet side tapered portion 51C, the central portion 52C, and the outlet side tapered portion 53C form the inlet portion 41C, the central portion 42C, and the outlet portion 43C between the outer peripheral surface 831C of the roller 8C. The film-like body M1 is arranged only in the central portion 42C of the waveguide 40C.

Further, the evaluation device 1C includes an inlet side lens 93 and an outlet side lens 94. The inlet side lens 93 is arranged between the transmitting portion 2 and the waveguide 40C. The outlet side lens 94 is arranged between the waveguide 40C and the receiving unit 3.

As shown in FIG. 12, the electromagnetic wave transmitted by the transmitting unit 2 enters the inlet portion 41C of the waveguide 40C as shown by the arrow A5. Since the width of the inlet portion 41C gradually decreases toward the central portion 42C, the moving distance of the electromagnetic wave in the radial direction of the roller 8C gradually decreases. As a result, the electromagnetic wave travels toward the central portion 42C while converging.

The electromagnetic wave that has passed through the inlet portion 41C then enters the central portion 42C. The dimension d of the central portion 42C is smaller than the wavelength of the electromagnetic wave. However, due to the action of the free electrons described above, the electromagnetic wave can travel through the central portion 42C while being repeatedly reflected by the reflecting surface 50C of the waveguide 5C and the outer peripheral surface 831C of the roller 8C. The electromagnetic wave repeatedly passes through the film-like body M1 supported by the outer peripheral surface 831C of the roller 8C in the thickness direction thereof. The electromagnetic wave is received by the receiving unit 3 after passing through the waveguide 40C.

As described above, in the evaluation device 1C, the transmitting unit 2 and the receiving unit 3 are arranged apart from each other in the direction in which the rotating shaft 81 extends. According to this configuration, since the length of the film-like body M1 arranged in the waveguide 40C is stable, it is possible to further improve the evaluation accuracy of the characteristics.

The embodiments described above are for facilitating the understanding of the present invention, and are not for limiting and interpreting the present invention. Each element included in the embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those exemplified, and can be changed as appropriate. In addition, the configurations shown in different embodiments can be partially replaced or combined.

In the above embodiment, electromagnetic waves are reflected on one side of the waveguides 5A, 5B1, 5B2, 5C made of aluminum. However, the present invention is not limited to this form. For example, the waveguide is made of a resin material or the like, and another member made of a metal material may be arranged on the surface of the roller 8 facing the outer peripheral surface 831, or a film of the metal material may be formed. good. In this case, the separate member or coating functions as a reflective surface.

In the above embodiment, the metal film 83 of the roller 8 is made of aluminum. However, the present invention is not limited to this form. For example, the metal film 83 may be formed by chrome plating. In this case, it becomes possible to exhibit higher durability against wear due to interference with the film-like body M1 as compared with the case where it is formed of aluminum.

1A, 1B: Evaluation device 2: Transmitter 3: Receiver 4: Waveguide members 40, 40A, 40B: Waveguides 50, 50A, 50B, 60: Reflective surfaces 51, 51A, 51B, 61: Inlet side taper 53 , 53A, 53B, 63: Outlet side taper part 7: Calculation unit 8: Roller 81: Rotating shaft 831: Outer peripheral surface 91, 93: Inlet side lens 92, 94: Exit side lens M, M1: Membrane

Claims (4)

An evaluation device that evaluates the characteristics of membranous bodies.
A roller that supports the film-like body by the outer peripheral surface,
A transmitter that emits electromagnetic waves and
A receiver that receives the electromagnetic waves transmitted by the transmitter and
A waveguide that is arranged between the transmitting unit and the receiving unit and guides the electromagnetic wave transmitted by the transmitting unit to the receiving unit side.
A calculation unit for deriving the characteristics of the film-like body by performing a predetermined calculation based on the electromagnetic wave received by the reception unit is provided.
The waveguide member has a reflective surface that faces the outer peripheral surface of the roller with a predetermined gap and is curved along a part of the outer peripheral surface to form a waveguide between the waveguide member and the outer peripheral surface. Have and
The reflective surface is an electromagnetic wave front Symbol transmitting portion is sent, is configured to direct the receiving portion while reflected between the outer peripheral surface of the roller, the predetermined gap is set to be equal to or less than the wavelength of the electromagnetic wave An evaluation device characterized by being The evaluation device according to claim 1, wherein at least the outer peripheral surface of the roller is formed of a metal material. The evaluation according to claim 1 or 2, wherein at least one of the reflecting surface and the outer peripheral surface of the roller is configured so that the width of the waveguide is widened at the inlet and the outlet of the waveguide. Device. The evaluation device according to claim 3, wherein the width of the inlet and the outlet of the waveguide is widened by using a curved surface of the outer peripheral surface of the roller.

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