JP6729970B2 - Evaluation device - Google Patents

Description

The present invention relates to an evaluation device that evaluates the characteristics of a film body.

An evaluation device for evaluating the characteristics of a sample is widely used. As such an evaluation device, a device that uses electromagnetic waves is known because it is less damaged even when the sample is irradiated.

Patent Document 1 describes an evaluation device of a system called terahertz time domain spectroscopy (THz-TDS method). The evaluation apparatus uses a terahertz wave that 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 transmitter that emits an electromagnetic wave and a receiver that receives the electromagnetic wave. A sample to be measured is placed between the transmitter and the receiver. When the sample is irradiated with the electromagnetic wave emitted from the transmitting unit, a part of the electromagnetic wave is absorbed by the sample and the other unit transmits the sample. The evaluation device, 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, The characteristics of the sample are evaluated.

JP-A-2002-277394

The degree of electromagnetic wave absorption by the sample depends on the distance that the electromagnetic wave penetrates through the sample and the absorption coefficient of the sample. When the distance that the electromagnetic wave penetrates through the sample is small, the electromagnetic wave absorbed by the sample is small. 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 body, since the electromagnetic wave transmission distance is small, the difference between the two current waveforms described above is also small. Therefore, the device described in Patent Document 1 has a problem that the characteristics of the film-shaped body cannot be evaluated accurately.

There is also a need to evaluate the characteristics of the molded product using the evaluation device before shipping. However, there is a problem in that the troublesome work of setting the film-shaped body in the evaluation device is required.

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

The present invention is an evaluation device for evaluating the characteristics of a film-shaped body, which supports the film-shaped body by an outer peripheral surface thereof and which conveys the film-shaped body by rotating about a rotation axis, and an electromagnetic wave. A transmitting unit for transmitting, a receiving unit for receiving the electromagnetic wave transmitted by the transmitting unit, a waveguide member arranged between the transmitting unit and the receiving unit for guiding the electromagnetic wave transmitted by the transmitting unit to the receiving unit side, and the receiving unit. And a calculation unit that derives the characteristics of the film-shaped body by performing a predetermined calculation based on the electromagnetic waves received by the electromagnetic wave. The waveguide member has a reflecting surface that faces the outer peripheral surface of the roller with a gap therebetween and forms a waveguide between the outer peripheral surface and the outer peripheral surface. The reflecting surface is configured to guide the electromagnetic wave emitted from the transmitting unit to the receiving unit while reflecting the electromagnetic wave with the outer peripheral surface of the roller.

According to the above configuration, the film-shaped body is supported by the outer peripheral surface of the roller and is conveyed by the rotation of the roller. The present invention thus evaluates the characteristics of the film-like material during transportation. Therefore, for example, the characteristics of the film-shaped body can be evaluated when the formed film-shaped body is conveyed from the molding machine by the roller. Therefore, it becomes possible to evaluate the characteristics of the film-shaped body with a little labor.

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 passes through the film-shaped body a plurality of times. As a result, it becomes possible to increase the transmission distance of electromagnetic waves in the film and accurately evaluate the characteristics of the film.

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

It is a schematic diagram which shows a principle model. 3 is a graph showing a current waveform acquired by the arithmetic unit of FIG. 1. 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 showing an evaluation device concerning a 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 showing an evaluation device concerning a 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 reference numerals are given to the same constituent elements in each drawing as much as possible, and overlapping description will be omitted.

[Principle model]
First, an 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 that evaluates the optical characteristics (for example, absorptance, refractive index, transmittance, etc.) of the film M by using terahertz time domain spectroscopy. The film body M is an object whose thickness dimension is smaller than other dimensions. Examples of the film M that can be evaluated include cotton fabric, cupra fabric, and resin film. As shown in FIG. 1, the principle model 1 includes a transmission unit 2, a reception unit 3, a waveguide member 4, and a calculation unit 7.

The transmitter 2 is a device that transmits electromagnetic waves to the external space. Specifically, the transmitter 2 generates a terahertz wave that is an electromagnetic wave having a frequency of 0.1 THz to 10 THz and a wavelength of 300 μm to 3 mm. The transmission unit 2 has a mechanism capable of transmitting terahertz waves, such as a femtosecond laser, a photoconductive antenna, a terahertz transmission resonant tunneling diode (RTD), a terahertz quantum cascade laser, and the like. In FIG. 1, these are simplified and the transmission part 2 is illustrated as one unit. The transmitter 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 apart from the transmitting unit 2. The receiver 3 has a plurality of members such as photoconductive elements. FIG. 2 simplifies these and illustrates the receiving unit 3 as one unit. The receiving unit 3 can receive the electromagnetic wave emitted 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 transmitter 2 and the receiver 3. The waveguide member 4 has a waveguide 40 inside. The waveguide 40 has an open end. Specifically, the waveguide member 4 has the waveguide plates 5 and 6 facing each other with a gap therebetween, and the gap corresponds to the waveguide 40. The film body M is arranged in a part of the waveguide 40. As will be described later, the electromagnetic wave emitted by the transmitter 2 is guided to the receiver 3 by passing through the waveguide 40.

In order to facilitate understanding, as shown in FIG. 1, the orthogonal direction in which the direction in which the waveguide plates 5 and 6 face each other is the Z direction and the direction orthogonal to the Z direction is the X direction and the Y direction is shown. It will be explained using. Coordinates corresponding to the rectangular coordinates are also shown in FIG. 3 and subsequent figures.

The calculation unit 7 is a device that derives the characteristics of the film M. The calculation unit 7 is connected to at least the reception unit 3. The calculation unit 7 derives the characteristics of the film 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 receiver 3 after the electromagnetic wave is emitted from the transmitter 2. The waveform of the current Er detected by the receiver 3 when the film M is not arranged in the waveguide 40 is indicated by the solid line. On the other hand, the waveform of the current Em detected by the receiver 3 when the film M is arranged in the waveguide 40 is indicated by a broken line. The waveforms of the current Er and the current Em have peaks at the timing when the electromagnetic wave is received by the receiving unit 3.

When the film M is not arranged in the waveguide 40, the electromagnetic wave emitted by the transmitter 2 reaches the receiver 3 with almost no absorption in the waveguide 40. In this case, the peak of the waveform of the current Er clearly appears. Such a waveform of the current Er has been acquired prior to the evaluation of the film body M.

On the other hand, when the film M is arranged in the waveguide 40, a part of the electromagnetic wave emitted by the transmitter 2 is absorbed by the film M in the waveguide 40. The other part of the electromagnetic wave passes through the film M, passes through the waveguide 40, and reaches the transmitter 2. That is, the waveform of the current Em shows that of the electromagnetic wave after the transmission including the multiple reflection. Therefore, the peak of the waveform of the current Em is smaller than that of the waveform of the current Er. The peak of the waveform of the current Em appears slightly behind the timing of the peak of the current Er.

The calculation unit 7 performs a predetermined process on each of the waveforms of the currents Er and Em. Specifically, the calculation unit 7 calculates each complex Fourier component of the waveforms of the currents Er and Em, and calculates the ratio of 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 body M, based on the complex amplitude transmittance obtained in advance by an experiment.

In the principle model 1 configured as described above, in order to evaluate the characteristics of the film 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 M in the waveguide 40.

Therefore, in the principle model 1, the structure of the waveguide member 4 is devised so that the difference between the waveforms of the currents Er and Em is 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 having the X-axis direction as the longitudinal direction and the Z-axis direction as the thickness direction. The waveguide plates 5 and 6 are made of aluminum. The dimension Lx of the waveguide plates 5 and 6 in the X-axis direction is about 90 mm. As shown in FIG. 3, the waveguide plates 5 and 6 have reflecting surfaces 50 and 60 on one side surface thereof.

The reflecting surfaces 50, 60 are smooth surfaces with little unevenness due to polishing. Thereby, as will be described later, scattering when the 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 central portions of the reflecting surfaces 50 and 60 in the X-axis direction. The dimension Lx1 of the flat portions 52 and 62 in the X-axis direction is about 30 mm. The waveguide plates 5 and 6 are arranged such 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 less than the wavelength of the electromagnetic wave emitted by the transmitter 2 (for example, 200 μm). A portion of the waveguide 40 formed between the flat portion 52 and the flat portion 62 is referred to as a film-shaped body disposing portion 42. In order to understand the explanation, the waveguide 40 is shown extremely large in FIGS.

The film body M is arranged in the film body arrangement portion 42 such that the thickness direction thereof is not orthogonal to the Z direction. Specifically, the film body M is arranged in the film body arrangement portion 42 such that the thickness direction thereof coincides with the Z direction and extends along the flat portions 52 and 62. Both ends of the film 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 taper portions 51 and 61 are located closer to the transmitter 2 (not shown in FIG. 3) than the flat portions 52 and 62, and are surfaces that are continuous with the flat portions 52 and 62. The entrance-side tapered portions 51 and 61 are curved so as to project toward the waveguide 40. A 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 and 61 are formed so as to gradually approach each other in the X-axis direction. In other words, the inlet portion 41 is formed so that its width gradually decreases in the X-axis direction.

The outlet taper portions 53 and 63 are surfaces that are located closer to the receiving unit 3 (not shown in FIG. 3) than the flat portions 52 and 62 and are 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. A portion of the waveguide 40 formed between the outlet-side taper portion 53 and the outlet-side taper portion 63 is referred to as an outlet portion 43. In the outlet part 43, the outlet side tapered parts 53 and 63 are formed so as to gradually separate from each other in the X-axis direction. In other words, the outlet portion 43 is formed so that its width gradually increases as it goes in the X-axis direction.

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

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 waves so as to be directed in the X direction. Further, since the width of the entrance portion 41 gradually decreases in the X-axis direction, the moving distance of the electromagnetic wave in the Z direction gradually decreases. As a result, the electromagnetic wave advances toward the film-shaped member placement portion 42 while converging.

The electromagnetic wave that has passed through the inlet portion 41 then enters the film-shaped body arranging portion 42 as shown in FIG. As described above, the dimension d of the film body placement portion 42 in the Z-axis direction is smaller than the wavelength of electromagnetic waves. Generally, it is difficult for an electromagnetic wave to pass through a gap whose size is smaller than the wavelength due to its diffraction limit.

In 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-shaped member placement 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 not present because it is shielded by free electrons in the metal. , The boundary condition that only the component perpendicular to the surface exists is satisfied. Even when the dimension d of the film-shaped member arranging portion 42 is set to be equal to or smaller 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-shaped member placement portion 42 while reciprocating in the Z direction. Therefore, the electromagnetic waves repeatedly pass through the film body M arranged in the film body arrangement portion 42 in the thickness direction thereof. Specifically, a part of the electromagnetic wave reaching the film body M is absorbed by the film body M, and the other part is transmitted through the film body M.

The electromagnetic wave that has passed through the film body placement portion 42 then enters the outlet portion 43 as shown in FIG. 7. As shown by an arrow A3, the electromagnetic wave reciprocates in the Z direction by being repeatedly reflected by the outlet side tapered portions 53 and 63.

Generally, when an apex angle is formed at the end of the waveguide, electromagnetic waves are diffracted at the apex angle. As a result, the electromagnetic waves diffuse from the end of the waveguide, and the electromagnetic waves that the receiving unit 3 can receive decrease.

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. This suppresses the diffusion of electromagnetic waves at the end of the waveguide 40. The electromagnetic wave that has passed through the outlet 43 in this manner is received by the receiver 3.

According to the principle model 1 configured as described above, the electromagnetic wave emitted by the transmitter 2 is guided to the receiver 3 while being reflected between the pair of reflecting surfaces 50 and 60. The film body M is arranged so that the thickness direction thereof is not orthogonal to the direction in which the reflecting surfaces 50 and 60 face each other. Therefore, the electromagnetic wave passes through the film body M multiple times in the thickness direction. As a result, it becomes possible to increase the transmission distance of the electromagnetic waves in the film M, and to evaluate the characteristics of the film M with high accuracy.

By the way, the smaller the dimension d of the film-shaped member arranging portion 42, the more the electromagnetic waves are converged on the film-shaped member arranging 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 body arranging portion 42 due to the diffraction limit.

Therefore, in the principle model 1, the reflecting surfaces 50 and 60 are made 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 waves, the electromagnetic waves interact with the free electrons existing on the reflecting surfaces 50 and 60, and thus the film-shaped body. It becomes possible to pass through the arrangement portion 42. As a result, it is possible to focus the electromagnetic wave on the film-shaped member disposing portion 42 and improve the evaluation accuracy of the characteristics. This configuration is particularly suitable when the electromagnetic wave emitted by the transmitter 2 is a terahertz wave having a longer wavelength than other electromagnetic waves.

Further, the reflecting surfaces 50, 60 have inlet-side taper portions 51, 61 for gradually reducing the width of the waveguide 40 from the transmitting portion 2 side toward the film-like body disposing portion 42 side. According to this configuration, it is possible to guide the electromagnetic wave emitted from the transmitting unit 2 to the film-shaped body disposing unit 42 while converging by the inlet-side taper 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 transmission unit 2 can be further directed to the film body placement 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 taper portions 53 and 63 that gradually increase the width of the waveguide 40 from the film-shaped body disposing 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 body placement unit 42 can be more reliably received by the receiving unit 3.

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

[First Embodiment]
The evaluation apparatus 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 apparatus 1A, and shows an enlarged vicinity of a waveguide plate 5A described later. Of the configurations of the evaluation device 1A, those having the same functions as those of the principle model 1 are designated by the same reference numerals, and the description thereof will be appropriately omitted.

The evaluation device 1A evaluates the optical characteristics of the film-shaped body M1 molded by a molding machine (not shown), and detects defects in the film-shaped body M1 based on the evaluation. The film body M1 has a strip shape and is formed by crosslinking a polymer with a molding machine. The evaluation device 1A detects whether or not there is a site where the polymer is not appropriately crosslinked in the film body M1.

The evaluation device 1A is incorporated in a transport device that transports the film body M1. The evaluation device 1A includes a transmitter 2, a receiver 3, a waveguide plate 5A, a calculator 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 body M1. The roller 8 has a substantially columnar shape and is rotatable about a rotation shaft 81 shown in FIG. The film body M1 is arranged so that the direction in which the rotating shaft 81 extends and the width direction thereof match, and one side surface of the film body M1 abuts against the outer peripheral surface 831 of the roller 8 and is supported thereby.

When an actuator (not shown) is driven, the roller 8 receives a force from the actuator and rotates in the direction indicated by arrow R1. With this rotation, the film body M1 advances toward the outer peripheral surface 831 of the roller 8 as indicated by an arrow A4. The film body M1 is folded back along the outer peripheral surface 831 and advances 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 columnar 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 a smooth surface with few irregularities by being polished. Thereby, 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 plate-shaped member. The waveguide plate 5A is made of aluminum and is curved so as to extend along a part of the outer peripheral surface 831 of the roller 8. Further, as shown in FIG. 9, the waveguide plate 5A faces the outer peripheral surface 831 with a gap of dimension d therebetween. The gap corresponds to the waveguide 40A. The film body M1 is arranged in the waveguide 40A. The transmitter 2 and the receiver 3 are arranged so as to face each other across 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 that of the waveguide member 4 of the principle model 1 described above.

As shown in FIG. 9, the waveguide plate 5A has a reflecting surface 50A on one side surface thereof. The reflecting surface 50A is a smooth surface having few irregularities by being polished. Further, the reflecting surface 50A has an inlet side taper portion 51A, a central portion 52A and an outlet side taper portion 53A.

The inlet-side taper portion 51A is a surface that is located closer to the transmitter 2 than the central portion 52A and is 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. A portion of the waveguide 40A 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 taper 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 41A is formed so that its width gradually decreases toward the receiving unit 3 side.

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

The outlet-side taper portion 53A is a surface that is located closer to the receiving unit 3 side than the central portion 52A and is 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. A portion of the waveguide 40A 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 part 43 is formed so that its width gradually increases toward the receiving part 3 side.

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

As shown in FIG. 9, the electromagnetic wave emitted by the transmitter 2 first enters one side surface of the entrance-side lens 91. By passing through the entrance-side lens 91, the electromagnetic wave diverges in the direction in which the rotation shaft 81 of the roller 8 extends, and exits from the other side surface. Thereby, the electromagnetic wave is emitted in a wide range in the width direction of the film body M1.

The electromagnetic wave transmitted through the entrance lens 91 enters the entrance portion 41A of the waveguide 40A. FIG. 9 schematically shows the traveling direction of the electromagnetic wave by an arrow A4. As indicated by an arrow A4, the electromagnetic wave reciprocates in the radial direction of the roller 8 by being repeatedly reflected by the entrance-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 entrance-side taper portion 51A reflects the electromagnetic wave so as to direct the receiving portion 3. Further, since the width of the entrance portion 41A gradually decreases toward the receiving portion 3 side, the moving distance of the electromagnetic wave in the radial direction of the roller 8 gradually decreases. As a result, the electromagnetic wave advances toward the central portion 42A of the waveguide 40A while converging.

By reciprocating in the radial direction of the roller 8, the electromagnetic waves repeatedly pass through the film 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 reaching the film body M is absorbed by the film body M, and the other part is transmitted through the film body M.

The electromagnetic wave that has passed through the entrance 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 electromagnetic waves. However, due to the interaction between the electromagnetic wave and the free electrons described above, the electromagnetic wave can travel through the central portion 42A.

The electromagnetic wave that has passed through the central portion 42A then enters the outlet portion 43A. As indicated by an 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. Thereby, the electromagnetic wave passes through the outlet 43A without being diffused at the end of the waveguide 40A.

The electromagnetic wave that has passed through the outlet portion 43A then enters one side surface of the outlet-side lens 92. The electromagnetic waves pass through the exit side lens 92 and are converged in the direction in which the rotation shaft 81 of the roller 8 extends, and are emitted from the other side surface. The electromagnetic wave is received by the receiving unit 3 arranged so as to face the other side surface of the exit lens 92.

The calculation unit 7 (see FIG. 8) acquires the current waveform from the reception unit 3. The calculation unit 7 evaluates the optical characteristics of the film body M1 based on the difference between the current waveform when the film body M1 is arranged in the waveguide 40A and the current waveform when the film body M1 is not arranged. .. Based on the optical characteristics, it can be detected that the polymer M1 has a site where the polymer is not appropriately crosslinked.

According to such a configuration of the evaluation device 1A, the film 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 thus evaluates the characteristics of the film-shaped body M1 being conveyed. Therefore, for example, the characteristics of the film-shaped body M1 can be evaluated when the formed film-shaped body M1 is conveyed from the molding machine by the roller 8. Therefore, it becomes possible to evaluate the characteristics of the film M1 with a small amount of time and effort.

Further, according to the configuration of the evaluation device 1A, the electromagnetic wave emitted by the transmitter 2 is guided to the receiver 3 while being reflected between the outer peripheral surface 831 of the roller 8 and the reflection surface 50A of the waveguide plate 5A. Therefore, the electromagnetic waves pass through the film body M1 a plurality of times in the thickness direction. As a result, it becomes possible to increase the electromagnetic wave transmission distance in the film body M1 and accurately evaluate the characteristics of the film body M1.

Further, the outer peripheral surface 831 of the roller 8 and the reflecting surface 50 of the waveguide plate 5A are made 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 waves are free electrons existing on the reflecting surface 50 and the outer peripheral surface 831. It becomes possible to pass through the waveguide 40A by the interaction with. As a result, it becomes possible to focus the electromagnetic wave on the waveguide 40A and improve the evaluation accuracy of the characteristics. This configuration is particularly suitable when the electromagnetic wave emitted by the transmitter 2 is a terahertz wave having a longer wavelength than other electromagnetic waves.

Further, the reflecting surface 50A has an inlet-side taper portion 51A that gradually reduces the width of the waveguide 40A from the transmitting portion 2 side toward the receiving portion 3 side. According to this configuration, it is possible to guide the electromagnetic wave emitted from the transmitting unit 2 to the receiving unit 3 side while converging it by the entrance-side taper 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 transmission unit 2 can be further directed to the reception unit 3 side. As a result, it becomes possible to converge the electromagnetic waves with high efficiency and further improve the accuracy of evaluation of the characteristics.

Further, the reflecting surface 50A has an outlet side taper portion 53A that gradually increases the width of the waveguide 40A from the transmitting portion 2 side toward the receiving portion 3 side. According to this configuration, it is possible to suppress the diffraction of the electromagnetic wave at the end of the waveguide 40A and to make the receiving unit 3 more reliably receive the electromagnetic wave that has passed through the waveguide 40A.

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

Further, the evaluation device 1A includes an exit-side lens 92 between the waveguide 40A and the receiver 3 for converging the electromagnetic wave that has passed through the waveguide 40A. According to this configuration, it is possible to converge the electromagnetic waves that diverge by passing through the entrance side lens 91 and pass through the waveguide 40A toward the receiving unit 3. As a result, the electromagnetic wave can be reliably received by the receiving unit 3 while transmitting the electromagnetic wave over a wide range of the film body M1.

[Modification]
An evaluation device 1B according to a 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 those of the principle model 1 and the configuration of the evaluation device 1A are designated by the same reference numerals, and the description thereof will be appropriately omitted.

The evaluation device 1B includes waveguide plates 5B1 and 5B2. The waveguide plates 5B1 and 5B2 are made of aluminum and are curved so as to extend along a part of the outer peripheral surface 831 of the roller 8. The waveguide plates 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 the outer peripheral surface 831 with a gap of dimension d therebetween. The gap serves as a waveguide independent of each other. The film body M1 is arranged so as to cross each waveguide.

Further, the evaluation device 1B includes two transmitters 2 and two receivers 3 (one transmitter 2 is not shown in FIG. 10). The transmitter 2 and the receiver 3 are arranged so as to face each other in the circumferential direction of the roller 8 with the waveguides in between. The waveguide plates 5B1 and 5B2, together with the metal film 83 of the roller 8, exhibit the same function as that of the waveguide member 4 of the principle model 1 described above.

Further, entrance-side lenses 911 and 912 and exit-side lenses 921 and 922 are arranged at the ends of the respective waveguides formed by the waveguide plates 5B1 and 5B2. In detail, the entrance side lens 911 and the exit side lens 921 are arranged to face each other with the waveguide formed by the waveguide plate 5B1 interposed therebetween, and the entrance side lens 912 and the exit side lens 912 are provided with the waveguide formed by the waveguide plate 5B2 interposed therebetween. The lens 922 is arranged so as to face it.

According to such a configuration of the evaluation device 1B, the electromagnetic waves emitted by the two transmitters 2 travel while reflecting on different waveguides, and are received by different receivers 3. Therefore, it is possible to evaluate the characteristics of the film body M1 for each part that differs in the direction in which the rotating shaft 81 extends. Therefore, when detecting a defect occurring in the film body M1 or the like, it is possible to specify the location of the defect in more detail.

[Second Embodiment]
An 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 taken along line XII-XII of FIG. 11, showing the vicinity of the waveguide plate 5C in an enlarged manner. Among the configurations of the evaluation device 1C, those having the same functions as those of the principle model 1 and the configurations of the evaluation devices 1A and 1B are designated by the same reference numerals, and the description thereof will be appropriately omitted.

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

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

As shown in FIG. 12, the waveguide plate 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 taper portion 51C, the center portion 52C, and the outlet-side taper portion 53C function similarly to the inlet-side taper portion 51A, the center portion 52A, and the outlet-side taper portion 53A according to the first embodiment. That is, the inlet-side taper portion 51C, the central portion 52C, and the outlet-side taper 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 body M1 is arranged only in the central portion 42C of the waveguide 40C.

In addition, the evaluation device 1C includes an entrance side lens 93 and an exit side lens 94. The entrance-side lens 93 is arranged between the transmitter 2 and the waveguide 40C. The exit-side lens 94 is arranged between the waveguide 40C and the receiver 3.

As shown in FIG. 12, the electromagnetic wave emitted by the transmitting unit 2 enters the inlet portion 41C of the waveguide 40C as indicated by an arrow A5. Since the width of the entrance 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 proceeds 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 electromagnetic waves. However, due to the action of the free electrons described above, the electromagnetic wave can travel in the central portion 42C while being repeatedly reflected by the reflecting surface 50C of the waveguide plate 5C and the outer peripheral surface 831C of the roller 8C. The electromagnetic waves repeatedly pass through the film 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 transmitter 2 and the receiver 3 are arranged apart from each other in the direction in which the rotary shaft 81 extends. According to this configuration, since the length of the film-shaped 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 the interpretation of the present invention. Each element included in the embodiment and its arrangement, material, condition, shape, size and the like are not limited to those illustrated, but can be appropriately changed. Further, the configurations shown in different embodiments can be partially replaced or combined.

In the above embodiment, the electromagnetic wave is reflected on one side surface of the waveguide plate 5A, 5B1, 5B2, 5C made of aluminum. However, the present invention is not limited to this form. For example, the waveguide plate may be formed of a resin material or the like, and another member formed of a metal material may be arranged on the surface of the roller 8 facing the outer peripheral surface 831 or a coating of a metal material may be formed. Good. In this case, the separate member and the coating function as a reflecting 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 is possible to exhibit higher durability against wear due to interference with the film body M1, as compared with the case of being 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 taper portion 53 , 53A, 53B, 63: outlet side taper portion 7: computing portion 8: roller 81: rotating shaft 831: outer peripheral surfaces 91, 93: inlet side lenses 92, 94: outlet side lenses M, M1: film-shaped body

Claims (7)

An evaluation device for evaluating the characteristics of a film body,
A roller that supports the film-shaped body by the outer peripheral surface and conveys the film-shaped body by rotating around a rotation axis,
A transmitter that emits electromagnetic waves,
A receiver for receiving the electromagnetic waves transmitted by the transmitter,
A waveguide member that is disposed between the transmitter and the receiver, and guides the electromagnetic wave emitted by the transmitter to the receiver.
An arithmetic unit for deriving the characteristics of the film-shaped body by performing a predetermined arithmetic operation based on the electromagnetic wave received by the receiving unit,
The waveguide member has a reflecting surface facing the outer peripheral surface of the roller with a gap, and forming a waveguide between the outer peripheral surface and the reflecting surface.
The reflecting surface is configured to guide the electromagnetic wave emitted by the transmitting unit to the receiving unit while reflecting the electromagnetic wave with the outer peripheral surface of the roller ,
The outer peripheral surface of the roller and the reflecting surface of the waveguide member are formed of a metal material,
The evaluation device , wherein the reflection surface of the waveguide member has a flat portion in which a gap between the reflection member and the outer peripheral surface of the roller is set to be equal to or less than the wavelength of the electromagnetic wave . The evaluation device according to claim 1 , wherein the reflection surface has an entrance-side taper portion that gradually reduces the width of the waveguide from the transmission unit side toward the reception unit side. The evaluation device according to claim 2 , wherein the inlet-side tapered portion is curved so as to project toward the outer peripheral surface side. The evaluation device according to claim 1 , wherein the reflection surface has an outlet-side tapered portion that gradually increases the width of the waveguide from the transmission unit side toward the reception unit side. The evaluation device according to claim 1 , further comprising: an entrance-side lens that disperses an electromagnetic wave emitted from the transmitting unit between the transmitting unit and the waveguide. The evaluation device according to claim 5 , further comprising: an exit-side lens that converges the electromagnetic wave that has passed through the waveguide, between the waveguide and the receiving unit. The evaluation device according to any one of claims 1 to 6 , wherein the transmitter and the receiver are arranged apart from each other in a direction in which the rotation shaft extends.