JP2016090550A - Information acquisition device and fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably fix an object, and to prevent the deterioration of measurement quality due to unnecessary reflected light.SOLUTION: An information acquisition device includes: irradiation means (110) for irradiating an object (500) with an electromagnetic wave; acquisition means (140) for detecting the electromagnetic wave reflected by the object, and for acquiring information related to the object; and fixing means (430) positioned at the back side of the object as viewed in the irradiation direction of the irradiation means for fixing the position of the object. The fixing means has absorption means (432) formed of members for absorbing the electromagnetic wave.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an information acquisition device that acquires information on an object by irradiating the object with electromagnetic waves, and a technical field of a fixture that fixes the object irradiated with electromagnetic waves.

  In recent years, research and development of terahertz wave imaging has been activated, and for example, it is expected to be applied to nondestructive inspection and the like. Specifically, a technique has been proposed for visualizing the internal structure of an object that cannot be seen by irradiating the object with terahertz waves and detecting the terahertz waves scattered by the object (for example, patents). Reference 1).

  As an imaging apparatus using electromagnetic waves other than terahertz waves, an apparatus using visible light is known (for example, see Patent Document 2).

Japanese Patent No. 4508578 JP 59-068728 A

  When imaging is performed using terahertz waves, scanning by a head that transmits and receives terahertz waves may be required. In such a case, vibration is generated by moving the head at a high speed, causing a technical problem that the positional relationship between the object and the head is shifted. In Patent Document 1, since the object is fixed to the groove portion, the movement of the object due to vibration may be avoided, but the shape of the object is limited by the shape of the groove portion. Is insufficient.

  On the other hand, in a reflection-type apparatus that detects a terahertz wave reflected by an object, a technical problem arises that the terahertz wave reflected from a place other than the object becomes noise and the imaging quality deteriorates. In Patent Document 1, since there is no configuration capable of reducing the above-described unnecessary reflected light, the above problem cannot be solved. Moreover, in patent document 2, since the mirror surface is provided in the scanner cover part and electromagnetic waves are actively reflected on the relationship which utilizes visible light, the said problem cannot be solved similarly.

  Examples of problems to be solved by the present invention include the above. An object of the present invention is to provide an information acquisition device and a fixture that can suitably fix an object and prevent deterioration of measurement quality due to unnecessary reflected light.

  An information acquisition device that solves the above problems includes an irradiation unit that irradiates an object with an electromagnetic wave, an acquisition unit that detects the electromagnetic wave reflected by the object and acquires information about the object, and the irradiation unit. A fixing means for fixing the position of the object located on the back side of the object as viewed in the irradiation direction, the fixing means having an absorbing means formed of a member for absorbing the electromagnetic wave.

  The fixture that solves the above problem is a fixture that fixes an object irradiated with electromagnetic waves, and is formed of a fixing surface that presses and fixes the object, and a member that absorbs the electromagnetic wave, And an absorbing means provided on a portion of the fixed surface irradiated with the electromagnetic wave.

It is a schematic block diagram which shows the whole structure of the information acquisition apparatus which concerns on an Example. It is a perspective view which shows the structure of the test object holding | maintenance part which concerns on 1st Example. It is a perspective view which shows the structure of the test object holding | maintenance part which concerns on 2nd Example. It is a perspective view which shows the structure of the test object holding | maintenance part which concerns on 3rd Example.

<1>
An information acquisition apparatus according to the present embodiment includes an irradiation unit that irradiates an object with electromagnetic waves, an acquisition unit that detects the electromagnetic waves reflected by the object and acquires information about the object, and the irradiation unit. A fixing means for fixing the position of the object located on the back side of the object as viewed in the irradiation direction, the fixing means having an absorbing means formed of a member for absorbing the electromagnetic wave.

  According to the information acquisition apparatus of this embodiment, electromagnetic waves are irradiated from the irradiation means toward the target object during the operation. The electromagnetic wave irradiated to the object is reflected at least partially by the object. And the electromagnetic wave reflected by the target object is detected by the acquisition means. The acquisition unit further acquires information about the object from the detected electromagnetic wave.

  In order to accurately acquire information about an object using electromagnetic waves, it is desirable that the position of the object is fixed with respect to the irradiation unit and the acquisition unit. For this reason, in this embodiment, the position of the object is fixed by the fixing means. The fixing method by the fixing means is not particularly limited. The fixing means is provided so as to be positioned on the back side of the object when viewed in the irradiation direction of the irradiation means (that is, the traveling direction of the irradiated electromagnetic wave). For this reason, a part of electromagnetic waves irradiated toward the object can be irradiated to the fixing means.

  Here, if the reflectance of the electromagnetic wave in the fixing unit is high, a large amount of the electromagnetic wave reflected by the fixing unit is incident on the acquisition unit. For this reason, the electromagnetic waves detected by the acquisition means include not only electromagnetic waves reflected by the object (that is, electromagnetic waves used for acquiring information on the object) but also electromagnetic waves reflected by the fixing means (that is, the object). Electromagnetic waves that become noise when acquiring information on the object) are also included, and as a result, the measurement quality related to the object deteriorates.

  However, in this embodiment, in particular, the fixing means has an absorbing means formed of a member that absorbs electromagnetic waves. For this reason, the electromagnetic wave irradiated to the fixing means is absorbed by the absorbing means, and the electromagnetic wave reflected by the fixing means is reduced. Therefore, the ratio of noise (that is, electromagnetic waves reflected by the fixing means) included in the electromagnetic waves detected by the acquisition means can be reduced. Accordingly, it is possible to suppress deterioration in measurement quality related to the object.

  In addition, it is preferable that an absorption means is provided in the position where the electromagnetic waves in a fixing means are easy to be irradiated. The absorbing means preferably has as high an absorptivity as possible with respect to electromagnetic waves, but the above-described effects can be obtained accordingly if the absorbing means is at least higher than that of the member forming the fixing means.

  As described above, according to the information acquisition apparatus according to the present embodiment, it is possible to prevent the positional deviation by fixing the object and prevent the reflection of unnecessary electromagnetic waves and suppress the deterioration of the measurement quality.

<2>
In one aspect of the information acquisition apparatus according to the present embodiment, the electromagnetic wave is a terahertz wave.

According to this aspect, the irradiation unit is configured as, for example, a photoconductive antenna (PCA), a resonant tunneling diode (RTD), or the like, and irradiates a terahertz wave toward an object. Similarly, the acquisition unit is configured to include a photoconductive antenna, a resonant tunneling diode, and the like, and detects the terahertz wave reflected by the object. The terahertz wave is an electromagnetic wave belonging to a frequency region (that is, a terahertz region) around 1 terahertz (1 THz = 10 ¹² Hz).

  According to the terahertz wave, it is possible to acquire information on the internal structure of an object that cannot be visually observed by using the characteristics. Even when terahertz waves are used, the measurement quality may be deteriorated due to reflection by the fixing means. However, if the fixing means has an absorbing means for absorbing terahertz waves, the deterioration of the measurement quality can be effectively suppressed.

<3>
In another aspect of the information acquisition apparatus according to this embodiment, the acquisition unit acquires an image of the object as information on the object.

  According to this aspect, it is possible to acquire an image of an object as a measurement result. However, if a large amount of electromagnetic waves that become noise is detected, it is difficult to acquire an appropriate image. However, in the present embodiment, since the fixing means has the absorbing means, electromagnetic waves that become noise are reduced. Therefore, it is possible to acquire an appropriate image with less noise.

<4>
In another aspect of the information acquisition apparatus according to the present embodiment, the irradiation unit includes a driving unit that drives the irradiation unit in a first direction and a second direction that intersects the first direction.

  According to this aspect, even when the irradiation range of the electromagnetic wave by the irradiation unit and the detection range of the electromagnetic wave by the acquisition unit are limited, measurement in a wider range is possible. Therefore, even when an electromagnetic wave having characteristics that limit the irradiation range and the detection range is used, or even when the object is large and the measurement range is wide, the measurement can be suitably performed.

  Note that the driving of the irradiation unit by the driving unit may cause vibrations in the apparatus. However, in this aspect, since the object is fixed by the fixing means, it is possible to suitably prevent the position displacement of the object due to vibration.

<5>
In another aspect of the information acquisition apparatus according to the present embodiment, the fixing means is a plate-like member, and the object is pressed by pressing the object toward a placement surface on which the object is arranged. Fix the position.

  According to this aspect, in a state where the object is arranged on the arrangement surface, the object is fixed by pressing by the fixing means that is a plate-like member. For this reason, it is possible to reliably fix the object with a relatively simple configuration.

  The arrangement surface in this aspect is provided between the irradiation unit and the acquisition unit and the object. It is preferable that the arrangement surface includes a material having a high transmittance with respect to the terahertz wave.

<6>
In the aspect which fixes an object by the press mentioned above, the fixing means may press the object by rotating around one side as a fulcrum.

  If comprised in this way, it is possible to fix an object suitably with a simple structure by rotation operation | movement of a fixing means.

<7>
Alternatively, in an aspect in which the object is fixed by pressing, the fixing means may move in a state parallel to the arrangement surface and press the object.

  If comprised in this way, the force added to a target object in the case of a press can be equalized. As a result, the degree of adhesion between the object and the arrangement surface can be made uniform and the occurrence of gaps can be suppressed, and the reduction in measurement quality caused by the gaps can be suppressed.

<8>
Further, in an aspect in which the object is fixed by pressing, the fixing means may press the object in a state where the distance and the inclination with respect to the arrangement surface can be adjusted.

  If comprised in this way, even if it is a thick target object or a tilted target object, it can press with equal force. That is, by adjusting the distance and the inclination of the fixing means with respect to the arrangement surface, it is possible to achieve uniform pressing on the objects having various shapes. As a result, the degree of adhesion between the object and the arrangement surface can be made uniform and the occurrence of gaps can be suppressed, and the reduction in measurement quality caused by the gaps can be suppressed.

<9>
The fixture according to the present embodiment is a fixture that fixes an object irradiated with electromagnetic waves, and is formed of a fixing surface that presses and fixes the object, and a member that absorbs the electromagnetic wave, And an absorbing means provided on a portion of the fixed surface irradiated with the electromagnetic wave.

  According to the fixture of the present embodiment, the object can be prevented from being displaced by pressing and fixing the object with the fixing surface. Therefore, it can prevent suitably that the irradiation state of the electromagnetic wave with respect to a target object or the reflection state of the electromagnetic wave in a target object will change.

  Moreover, according to the fixture of this embodiment, the absorption means formed with the member which absorbs electromagnetic waves is provided in the part to which the electromagnetic waves of a fixed surface are irradiated. For this reason, the electromagnetic waves reflected on the fixed surface can be reduced. Therefore, noise reduction can be realized in measurement using electromagnetic waves reflected by the object.

  The operation and other gains of the information acquisition device and fixture according to the present embodiment will be described in more detail in the following examples.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Device configuration>
First, the overall configuration of the information acquisition apparatus according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram illustrating the overall configuration of the information acquisition apparatus according to the embodiment.

  In FIG. 1, the information acquisition apparatus according to the present embodiment irradiates a test object 500 with a terahertz wave and detects the terahertz wave reflected from the test object 500. Thus, the information acquisition apparatus according to the present embodiment is configured as a so-called reflective terahertz wave measuring apparatus.

The terahertz wave is an electromagnetic wave belonging to a frequency region (that is, a terahertz region) around 1 terahertz (1 THz = 10 ¹² Hz). The terahertz region is a frequency region that combines light straightness and electromagnetic wave transparency. The terahertz region is a frequency region in which various substances have unique absorption spectra. Therefore, the information acquisition apparatus can analyze the characteristics of the inspection target 500 by analyzing the frequency spectrum of the terahertz wave irradiated on the inspection target 500.

  As shown in FIG. 1, the information acquisition apparatus according to the present embodiment includes an imaging head unit 100, a control / signal processing unit 200, a head scanner unit 300, and an inspection object holding unit 400. . Below, the concrete structure of each part is demonstrated with the operation | movement.

  During the operation of the information acquisition apparatus according to the present embodiment, a terahertz wave beam is emitted from the terahertz wave transmission unit 110 which is a specific example of “irradiation unit”. Specifically, for example, the terahertz wave generated in the terahertz wave generating element 111 configured to include a resonant tunnel diode or the like is efficiently extracted by the silicon hemispherical lens 112 and emitted as a terahertz wave beam through the collimator lens 113. Is done.

  The terahertz wave beam emitted from the terahertz wave transmission unit 110 passes through the beam splitter 120 and is irradiated to the inspection object 500 through the objective lens 130 and the sample stage 420. The irradiated terahertz wave beam is reflected on the inspection object 500. The reflected terahertz wave beam is incident on the beam splitter 120 via the sample stage 420 and the objective lens 130 again. The terahertz wave beam is reflected by the beam splitter 120 and guided to the terahertz wave receiving unit 140 which is a specific example of “acquiring means”.

  The terahertz wave receiving unit 140 detects a terahertz wave as having information about the object. Specifically, the terahertz wave beam collected by the condenser lens 141 is efficiently collected by the terahertz wave detection element 143 in the silicon hemisphere lens 142, and a signal corresponding to the intensity of the terahertz wave is detected.

  Each configuration described above is housed in the imaging head unit 100. The imaging head unit 100 is automatically scanned on the head scanner unit 300.

  The head scanner unit 300 includes a carriage 310 and a scanning mechanism 320. The imaging head unit 100 is installed on the carriage 310. Then, the carriage 310 moves two-dimensionally by driving a scanning mechanism 320 configured by, for example, a ball screw and a stepping motor. Thereby, scanning by the imaging head unit 110 fixed to the carriage 310 is realized.

  On the other hand, various controls for the imaging head unit 100 and the head scanner unit 300, and a control / signal processing unit 200 for processing signals detected by the imaging head unit 100, a signal amplification unit 210, a bias generation unit 220, a lock The in-detection unit 230, the scanner driving unit 240, and the image processing unit 250 are provided.

  The signal amplification unit 210 amplifies the signal detected by the terahertz wave reception unit 140 and outputs the amplified signal to the lock-in detection unit 230 as a terahertz wave reception data signal.

  The bias generation unit 220 generates a bias voltage to bias the terahertz wave generation element 111 and the terahertz wave detection element 143, and changes the terahertz wave transmitted or received according to the bias voltage. In the case where the terahertz wave generating element 111 and the terahertz wave detecting element 143 are photoconductive antennas, it is necessary to further apply light, and transmission / reception of a very wide band terahertz wave is performed by irradiating ultrashort pulse laser light be able to.

  Since the terahertz wave transmitted or received by the terahertz wave generating element 111 and the terahertz wave detecting element 143 is generally weak, lock-in detection is used for the detection. At the time of lock-in detection, the terahertz wave transmission unit 110 uses a reference signal modulated as a bias voltage of the terahertz wave generation element 111. The lock-in detection unit 230 performs synchronous detection using the detection signal based on the terahertz wave modulated by the bias generation unit 220 and the reference signal output from the bias generation unit 220. Then, noise components having different frequencies from the reference signal of the terahertz wave detection signal are removed. On the other hand, as the bias voltage of the terahertz wave detecting element 143, a DC voltage that increases the detection sensitivity in the characteristics of the terahertz wave generating element 111 is applied.

  The scanner driving unit 240 generates a driving signal for the scanning mechanism 320 of the head scanner unit 300, and at the same time, performs imaging to monitor where the terahertz wave beam emitted from the imaging head as a result of driving is located in the inspection object 500. A position signal is generated.

  The image processing unit 250 generates a mapped terahertz wave image image based on the imaging position signal monitored by the scanner driving unit 240 and the terahertz wave reception data signal generated by the signal amplification unit 210.

  The inspection object holding unit 400 includes a sample table 420, a scanner cover unit 430, and a housing 410 for fixing the sample table 420 and the scanner cover unit 430.

  The sample stage 420 includes a material (for example, ultrahigh molecular weight polyethylene) that efficiently transmits terahertz waves. For this reason, the inspection object 500 placed on the sample stage 420 can be imaged using the terahertz wave transmitted from the imaging head unit 100 below the sample stage 420. The sample stage 420 functions as a specific example of “arrangement surface”.

  The scanner cover unit 430 presses the inspection target 500 against the sample stage 420 and fixes the position, and also prevents the terahertz wave beam transmitted from the imaging head unit 100 from being reflected outside the inspection target 500. And an outer lid 431 for attaching the inner lid 432. The inner lid 432 further serves to prevent leakage of terahertz waves to the outside of the apparatus and unwanted terahertz waves from entering the apparatus. The scanner cover 430 is a specific example of “fixing means” and “fixing tool”, and the inner lid 432 is a specific example of “absorbing means”.

  The inner lid 432 efficiently absorbs terahertz waves and includes a flexible material (for example, polyurethane, chloroprene rubber, nitrile rubber, wool carpet, etc.), and the outer lid 431 has a hard material (for example, , ABS resin, aluminum, etc.).

  In this embodiment, in particular, since the inner cover 432 using the terahertz wave absorbing material is attached to the scanner cover 430, the position of the inspection object 500 placed on the sample stage 420 is pressed and fixed, and the imaging head The terahertz wave irradiated from the unit 100 can be prevented from being reflected by the scanner cover unit 430. Therefore, for example, it is possible to prevent the position of the inspection object 500 from being shifted due to vibration generated when the imaging head unit 100 is operated, and accurate measurement cannot be performed. Further, it is possible to prevent the terahertz wave reflected by the scanner cover 430 from becoming noise and degrading the measurement quality.

<Configuration example of scanner cover>
Hereinafter, a specific configuration example of the scanner cover portion 430 will be described with reference to FIGS. FIG. 2 is a perspective view showing the configuration of the inspection object holding unit according to the first embodiment. FIG. 3 is a perspective view showing the configuration of the inspection object holding unit according to the second embodiment, and FIG. 4 is a perspective view showing the configuration of the inspection object holding unit according to the third example.

  In FIG. 2, in the inspection object holding part 400a according to the first embodiment, one side of the scanner cover part 430 is connected to the housing 410 by an opening / closing mechanism 440a such as a hinge. As a result, the scanner cover 430 can be rotated about the opening / closing mechanism 440a. If the scanner cover portion 430 is configured in this manner, the inspection object 500 can be pressed and fixed with an extremely easy operation.

  In FIG. 3, in the inspection object holding part 400b according to the second embodiment, two opposite sides of the scanner cover part 430 are connected to the housing 410 by an extendable opening / closing mechanism 440b. As a result, the scanner cover 430 can move in parallel with the sample stage 420 and the inspection object 500. If the scanner cover portion 430 is configured in this way, the force applied to the inspection object 500 at the time of pressing can be made uniform. Therefore, the degree of adhesion between the inspection object 500 and the sample stage 420 can be made uniform to suppress the generation of gaps, and the deterioration of measurement quality caused by the gaps can be suppressed.

  In FIG. 4, in the inspection object holding part 400c according to the third embodiment, the four corners of the scanner cover part 430 are fixed to the housing 410 using an opening / closing mechanism 440c that is a screw. This makes it possible to adjust the distance and inclination of the scanner cover 430 from the sample stage 420. If the scanner cover portion 430 is configured in this manner, even a thick inspection object 500 or an inclined inspection object 500 can be pressed with an equal force. Therefore, as in the second embodiment, the degree of close contact between the inspection object 500 and the sample stage 420 can be made uniform to suppress the occurrence of gaps, and the reduction in measurement quality caused by the gaps can be suppressed. It is.

  In addition, each Example mentioned above is an example to the last, and the scanner cover part 430 can take various structures as a member which presses and fixes the test object 500. FIG.

  As described above, according to the information acquisition apparatus according to the present embodiment, the scanner cover unit 430 having the inner lid 432 capable of absorbing the terahertz wave is provided, so that the object is suitably fixed and unnecessary. It is possible to prevent the measurement quality from being deteriorated by the reflected light.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope or spirit of the invention that can be read from the claims and the entire specification. And fixtures are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Imaging head part 110 Terahertz wave transmission part 111 Terahertz wave generation element 112 Silicon hemisphere lens 113 Collimate lens 120 Beam splitter 130 Objective lens 140 Terahertz wave receiving part 141 Condensing lens 142 Silicon hemisphere lens 143 Terahertz wave detection element 200 Control and signal processing Unit 210 Signal amplification unit 220 Bias generation unit 230 Lock-in detection unit 240 Scanner drive unit 250 Image processing unit 300 Head scanner unit 310 Carriage 320 Scan mechanism 400 Inspection object holding unit 410 Housing 420 Sample stage 430 Scanner cover unit 431 Outer lid 432 Inner lid 440 Opening and closing mechanism 500 Inspection target

Claims (9)

An irradiation means for irradiating the object with electromagnetic waves;
An acquisition means for detecting the electromagnetic wave reflected by the object and acquiring information about the object;
A fixing means for fixing the position of the object located on the back side of the object as seen in the irradiation direction of the irradiation means;
The information acquisition apparatus, wherein the fixing unit includes an absorbing unit formed of a member that absorbs the electromagnetic wave.   The information acquisition apparatus according to claim 1, wherein the electromagnetic wave is a terahertz wave.   The information acquisition apparatus according to claim 1, wherein the acquisition unit acquires an image of the object as information about the object.   4. The information acquisition apparatus according to claim 1, further comprising a driving unit that drives the irradiation unit in a first direction and a second direction intersecting the first direction. 5.   The said fixing means is a plate-shaped member, and fixes the position of the said target object by pressing the said target object to the arrangement | positioning surface side by which the said target object is arrange | positioned. The information acquisition device according to any one of the above.   The information acquisition apparatus according to claim 5, wherein the fixing unit presses the object by rotating around one side as a fulcrum.   The information acquisition apparatus according to claim 5, wherein the fixing unit moves in a state parallel to the arrangement surface and presses the object.   The information acquisition apparatus according to claim 5, wherein the fixing unit presses the object in a state in which a distance and an inclination with respect to the arrangement surface can be adjusted. A fixture for fixing an object irradiated with electromagnetic waves,
A fixing surface for pressing and fixing the object;
A fixing tool comprising: an absorbing means that is formed of a member that absorbs the electromagnetic wave, and is provided on a portion of the fixing surface that is irradiated with the electromagnetic wave.

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