JP2007108129A - Device for detecting object to be measured - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate detection of an object to be measured in a short distance on the occasion of detecting the object to be measured by irradiation with an electromagnetic wave, and prevent lowering of detection sensitivity caused by interference objects being between the object to be measured and an object-to-be-measured detecting device. <P>SOLUTION: This object-to-be-measured detecting device 1 is provided with a light projecting unit 4 for diffusively radiating a pulse laser beam, a convex lens 9 for converting the laser beam radiated from the projecting unit 4 into parallel light, a light receiving unit 5 for receiving via the convex lens 9, a laser beam which is generated by the conversion with the convex lens 9, irradiates the object to be measured 14, and is reflected by the object 14, a PBS 6 which is interposed between the projecting unit 4 and the convex lens 9 and between the receiving unit 5 and the convex lens 9, guides the laser beam emitted from the projecting unit 4 to the convex lens 9, and moreover guides the laser beam reflected by the object 14 to the receiving unit 5 from the convex lens 9, and a distance detecting unit 13 which compares the laser beam emitted from the projecting unit 4 with the laser beam received by the receiving unit 5, and detects its distance up to the object 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a device for detecting a measurement object that detects an object to be measured based on the electromagnetic wave that is radiated from the measurement object and reflected by the measurement object and returned.

  As is well known, an object detection device is formed by radiating electromagnetic waves such as laser light or radio waves from a radiating means, scanning the radiated electromagnetic waves into a surrounding space while being reflected by a rotating mirror, and forming by scanning the electromagnetic waves. The electromagnetic wave reflected and returned from the scanning area is received by the wave receiving means, and based on the received electromagnetic wave, the presence or absence of the object to be measured in the scanning area and the distance to the object to be measured are detected. Is common.

  As an example of this type of device to be measured, there is a device described in Patent Document 1 below, for example. As shown in FIG. 2, the device under test 100 described in the document uses laser light as electromagnetic waves, and emits a spot shape of the laser light from the light projecting unit 101 into a line shape. An object to be measured is irradiated with this line-shaped laser beam. More specifically, the line-shaped laser light emitted from the light projecting unit 101 is incident on the rotating mirror 103 via the light projecting lens 102 disposed on the optical axis. The rotating mirror 103 is inclined at a predetermined angle with respect to the optical axis, and the line-shaped laser light incident on the rotating mirror 103 is reflected in a predetermined direction. The rotating mirror 103 is rotated about the optical axis, and a line-shaped laser beam is scanned around. The laser beam reflected by the object to be measured in the scanning region is reflected again by the same rotating mirror 103 and focused by the light receiving lens 104 separately formed in a donut shape around the light projecting lens 102. The light receiving unit 105 receives light.

US Pat. No. 6,759,649

  However, in the measured object detection apparatus 100 described in Patent Document 1 described above, the light projecting unit 101 and the light projecting lens 102 are located at the center of the light receiving lens 104. Has a problem that the light receiving unit 105 cannot receive light.

  Further, since the line-shaped laser light is irradiated to the object to be measured in the scanning region, the laser light irradiation region is expanded in the longitudinal direction of the laser light as compared with the case where the dot-shaped laser light is irradiated. Therefore, it is possible to reduce the influence of an obstructing object such as dust existing in the optical path of the laser beam that hinders the detection of the object to be measured, and to improve the detection sensitivity of the object to be measured in the scanning region.

  However, in the DUT 100 described in the same document, the ability to reduce the influence of the obstructing object is limited only to the longitudinal direction of the laser beam. For example, when the length of the laser beam in the longitudinal direction is 10 mm and the cross-sectional shape perpendicular to the laser beam irradiation direction of the obstructing object is a circle with a diameter of 5 mm, the irradiated laser beam is transmitted between the object detection device and the object to be measured. In the case of irradiating the obstructing object between the two, about half of the irradiated laser light is reflected from the obstructing object, and only the remaining half is reflected from the object to be measured. In this case, it is difficult to normally detect the object to be detected.

  The length of the laser beam in the longitudinal direction is limited by the size of the light projection lens 102. In addition, the size of the light projecting lens 102 is limited by the size of the light receiving lens 104 formed around it. Therefore, it may be difficult to set the length of the laser beam in the longitudinal direction to 10 mm or more.

  Note that the above problem can occur in the same manner even when electromagnetic waves other than laser light are used.

  It is an object of the present invention to facilitate the detection of an object to be measured at a short distance when detecting the object to be measured by irradiation with electromagnetic waves, and to detect by an obstructing object between the object to be measured and the object to be measured. The purpose is to improve the decrease in sensitivity.

  An object detection apparatus according to the present invention, which was created to solve the above-described problems, includes a radiation means for radiating pulsed electromagnetic waves in a diffuse manner, and a radiation form of the electromagnetic waves emitted from the radiation means in a diffuse manner. First radiation form conversion means for converting into a parallel straight radiation form, and the electromagnetic wave converted by the first radiation form conversion means is irradiated on the object to be measured, and the electromagnetic wave reflected from the object to be measured is converted to the first radiation form. Between the receiving means for receiving the wave via the means, the radiating means and the first radiating means converting means, and between the receiving means and the first radiating means converting means, and radiated from the radiating means. A demultiplexing means for guiding the electromagnetic wave to the first radiation form converting means, and a electromagnetic wave reflected from the object to be measured from the first radiation form converting means to the wave receiving means, an electromagnetic wave radiated from the radiation means, and a wave receiving means Compared with the electromagnetic wave received by the It is obtained by a distance detecting means for detecting a distance to the object to be measured or from reception means. The above-mentioned "parallel straight radiation form" includes not only a radiation form in which the electromagnetic wave radiation form travels in parallel in a geometrical manner, but also a radiation form in which the electromagnetic radiation form travels substantially in parallel. Including cases that can be considered.

According to such a configuration, the electromagnetic waves radiated diffusely from the radiating means pass through the first radiating form converting means, so that the parallel rectilinear radiating form having the effective cross-sectional shape of the first radiating form converting means. Is converted to For example, the effective cross-sectional shape of the first radiation form converting means is a circle having a diameter of 30 mm. In this case, the diameter of the electromagnetic wave irradiated to the object to be measured through the first radiation form converting means is a circle of 30 mm. This can be easily realized by releasing the device under test according to the present invention from the serious restriction on the size of the projection lens 102 in Patent Document 1. Here, as exemplified in the description of Patent Document 1, a case is considered in which there is an obstructing object having a diameter of 10 mm between the measured object detection apparatus according to the present invention and the measured object. In this case, since the electromagnetic wave irradiated to the object to be measured through the first radiation form converting means is a circle having a diameter of 30 mm, its area is about 707 mm ² . On the other hand, the area of the obstruction object having a diameter of 10 mm is about 79 mm ² . Therefore, only 79/707 = 0.11 minutes of the irradiated electromagnetic wave is reflected from the obstructing object, and the other 1-0.11 = 0.89 minutes is reflected from the object to be measured which is the detection target. The measured object detection apparatus according to Patent Document 1 is easily affected by the obstruction object having a diameter of 5 mm, whereas the measurement object detection apparatus according to the present invention is influenced by the obstruction object having a diameter of 10 mm, for example. It can be greatly reduced.

  Further, in the device under test according to the present invention, even when the distance between the first radiation pattern changing means and the device under test is extremely short, for example, 1 cm, the electromagnetic wave reflected by the device under test is It is possible to reliably reach the wave receiving means through the first radiation form converting means and the demultiplexing means. This is because, in the measured object detection apparatus 100 in Patent Document 1, the light projecting unit 101 and the light projecting lens 102 exist in the center of the optical path where the reflected light from the measured object reaches the wave receiving means. On the other hand, in the device under test apparatus according to the present invention, the effect obtained because there is no object that obstructs the waveguide path of the electromagnetic wave until the electromagnetic wave reflected by the device under test reaches the wave receiving means.

  In the device under test according to claim 2 of the present invention, the device is disposed between the radiating means and the demultiplexing means, or between the demultiplexing means and the first radiation form converting means, and the first radiation form. Second radiation form conversion means for shaping the radiation form of the electromagnetic wave diffusively radiated from the radiation means so that the cross-sectional shape orthogonal to the wave axis of the electromagnetic wave that has passed through the conversion means is circular. The “circular shape” includes not only a true circular shape but also an elliptical shape that can be regarded as a substantially circular shape.

  If it does in this way, the electromagnetic wave radiated | emitted from the radiation | emission means will be shape | molded by the 2nd radiation | emission form conversion means at the step which enters the 1st radiation | emission form conversion means, and will pass through the 1st radiation form conversion means. The electromagnetic wave thus obtained has a cylindrical radiation form. Thereby, even if the electromagnetic wave radiated from the radiating means is not conical, the effect of the present invention to reduce the influence when there is an obstructing object between the measured object detection device and the measured object, It is possible to make the most of it. Specifically, when a semiconductor laser (LD: Laser Diode) is used as the radiating means, the laser beam emitted from the semiconductor laser has a divergence angle with respect to the optical axis (wave axis) of, for example, 5 ° to 30 °. In many cases, the cross-sectional shape changes sequentially in the range, and the cross-sectional shape orthogonal to the optical axis of the radiation form is elliptical. Therefore, for example, a cylindrical lens is used as the second radiation form changing means, and the spread angle of the laser light with respect to the optical axis can be made substantially constant, for example, 30 °.

  The device under test according to claim 3 of the present invention further includes wavefront control means that is disposed between the radiation means and the first radiation form conversion means and controls the wavefront of the electromagnetic wave.

  In this way, the electromagnetic wave radiated from the radiating means is reflected by the object to be measured and can efficiently reach the wave receiving means. A polarization beam splitter (PBS: Polarizing) that uses an LD as a radiation means, efficiently reflects only light having a specific linear polarization plane as a branching means, and transmits most of light having a polarization plane perpendicular to the polarization plane. A case where Beam Splitter is used will be described as an example. The semiconductor laser emits light having a linear polarization plane in a specific direction. This polarization plane is set in the direction in which the polarization beam splitter efficiently reflects light, and a λ / 4 plate, which is a kind of wavefront control means, is arranged between the polarization beam splitter and the lens that is the first radiation form conversion means. To do. The laser light emitted from the semiconductor laser and reflected by the polarization beam splitter has a linear polarization plane in a specific direction, but the laser light that has passed through the λ / 4 plate is circularly polarized. When this laser beam is reflected by the object to be detected, it becomes a circularly polarized wave whose rotational direction with respect to the traveling direction of the light is reversed with respect to the circularly polarized wave. When the circularly polarized laser beam whose rotation direction is reversed passes through the λ / 4 plate again, it becomes a linearly polarized laser beam having a polarization plane different by 90 ° from the linear polarization plane in the specific direction. When laser light having such a polarization plane enters the polarization beam splitter, most of the incident laser light passes through the polarization beam splitter and reaches the wave receiving means.

  Naturally, an optical element that appropriately rotates the polarization plane of the light emitted from the semiconductor laser in order to align the polarization plane of the light emitted from the semiconductor laser and the direction of the polarization plane characteristic of the polarization beam splitter. May be arranged between the radiating means and the demultiplexing means.

  In the measured object detection apparatus according to claim 4 of the present invention, a reflecting means that is disposed between the demultiplexing means and the measured object and reflects electromagnetic waves radiated through the demultiplexing means in a predetermined direction; A rotation driving means for rotating the reflecting member around the wave axis of the electromagnetic wave reaching the reflecting member via the branching means, and an angle detecting means for detecting the angular position of the reflecting member; The position of the object to be measured is detected based on the distance to the object to be measured and the angular position of the reflecting member.

  In this way, not only the distance to the object to be measured but also the position where the object to be measured exists can be detected.

  In the measured object detection apparatus according to claim 5 of the present invention, the outermost part is covered with a housing provided with a transmission window that transmits electromagnetic waves.

  In this way, it is possible to prevent the entry of obstructing objects such as dust into the housing without interfering with the electromagnetic wave waveguide path, and it becomes possible to stably detect the object to be measured. . In addition, even if an obstructing object is attached to the transmission window of the housing, the radiation form of the electromagnetic wave is a parallel straight radiation form having an effective sectional shape of the first radiation form conversion means. Therefore, most of the electromagnetic wave travels through the transmission window without being affected by the obstructing object, so that the detection sensitivity of the object to be measured can be maintained well. Accordingly, it is possible to reduce the cleaning operation of the transmission window, and as a result, the apparatus can be used continuously for a long period of time.

  In the above configuration, for example, laser light or radio waves can be used as the electromagnetic waves radiated from the radiating means.

  According to the present invention as described above, the electromagnetic wave diffusively radiated from the radiating means passes straight through the first radiation form converting means, and travels straight in parallel with the effective sectional shape of the first radiation form converting means. Therefore, even if there is an inhibitory object such as dust on the electromagnetic wave guide path, the influence of the inhibitory object is greatly reduced and the object to be detected is detected. It becomes possible to detect reliably. In addition, since the electromagnetic wave reflected by the object to be measured reliably reaches the wave receiving means through the first radiation form converting means and the demultiplexing means, the object to be measured exists in a short distance. In addition, the object to be measured can be easily detected.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic longitudinal sectional view showing the overall configuration of a device under test detection apparatus according to an embodiment of the present invention. This device under test 1 uses laser light as an electromagnetic wave, and includes a light projecting part (radiating means) 4 and a light receiving part inside a housing 3 provided with a cylindrical light projecting / receiving window (transmission window) 2. Unit (wave receiving means) 5, polarization beam splitter (demultiplexing means) 6, cylindrical lens (second radiation form converting means) 7, λ / 4 plate (wavefront control means) 8, and convex lens (first radiation) A measuring object detecting device main body including a shape converting means) 9, a rotating mirror (reflecting member) 10, a rotation driving unit 11, an angle detecting unit 12, and a distance detecting unit 13 as basic components is stored. Has been.

  More specifically, the light projecting unit 4 emits a pulsed laser beam in the horizontal direction (left-right direction in FIG. 1) while diffusing the pulsed laser beam at a spread angle (for example, half-value width: 5 ° to 30 °) of the laser light emitting element. It is like that. The laser light emitted from the light projecting unit 4 has a substantially conical radiation form in which a cross-sectional shape (spot shape) orthogonal to the optical axis X is an ellipse. Specifically, in the present embodiment, a semiconductor laser is used as the light projecting unit 4. Generally, the plane of polarization of laser light emitted from the semiconductor laser 4 is parallel to the minor axis direction of the ellipse. Note that the pulsed laser light here includes not only so-called isolated pulses but also laser light subjected to predetermined intensity modulation that is emitted intermittently.

  Then, the laser light emitted from the semiconductor laser 4 is incident on the cylindrical lens 7 disposed on the optical axis X. The cylindrical lens 7 adjusts the divergence angle in the minor axis direction of the elliptical cross-sectional shape radiated from the semiconductor laser 4 from about 5 ° to about 30 °, and the divergence angle in the major axis direction of the ellipse orthogonal to this direction. Has no effect. In other words, the laser light that has passed through the cylindrical lens 7 has a conical radiation form in which the divergence angle is approximately 30 ° and the cross-sectional shape that is substantially constant is substantially circular.

  The laser light that has passed through the cylindrical lens 7 is incident on the polarization beam splitter 6. The polarization beam splitter 6 is arranged such that the polarization plane in the direction in which the laser beam is easily reflected faces in the vertical direction (vertical direction in FIG. 1). At this time, the minor axis direction of the elliptical cross-sectional shape of the laser light emitted from the semiconductor laser 4 is set in advance in the same direction. Then, most of the laser light emitted from the semiconductor laser 4 is reflected upward in the vertical direction by the polarizing beam splitter 6 via the cylindrical lens 7. The convex lens 9 converts the radiation form of the laser beam reflected upward in the vertical direction by the polarization beam splitter 6 from a conical shape to a cylindrical shape and guides it upward in the vertical direction. The laser beam that has passed through the convex lens 9 has a substantially circular cross-sectional shape orthogonal to the optical axis Y. In this embodiment, the convex lens 9 is composed of a single lens having an effective diameter of a single focal length of 10 mm or more.

  The rotating mirror 10 is tilted at about 45 degrees with respect to the optical axis Y of the laser beam showing a columnar radiation shape guided upward in the vertical direction, and is rotationally driven by the rotational driving unit 11 around the optical axis Y. The housing 3 is rotated with the convex lens 9 reflecting the cylindrical radiation beam in the horizontal direction while being horizontally reflected, and the optical axis Y is centered through the light projecting / receiving window 2 of the housing 3. Laser light is scanned in an external surrounding space.

  On the other hand, the laser light introduced into the housing 3 in the substantially horizontal direction through the light projecting / receiving window 2 of the housing 3 is reflected vertically downward by the rotating mirror 10 and is almost the same optical path as the laser light emitted from the semiconductor laser 4. The light is focused in the conical radiation form by the same convex lens 9, passes through the polarization beam splitter 6, and is focused on the position of the light receiving unit 5. As the light receiving unit 5, for example, an optical sensor such as a photodiode is used.

  In the present embodiment, the angle detection unit 12 that detects the scanning angle of the rotary mirror 10 rotates in synchronization with the rotary mirror 10 and has a plurality of optical slits extending in the radial direction arranged in the circumferential direction. The slit plate 12a and the photo interrupter 12b arranged and fixed on the rotation path of the slit plate 12a are configured, and the scanning angle of the rotary mirror 10 detected by the photo interrupter 12b is input to the distance detection unit 13.

  The distance detection unit 13 compares the laser light emitted from the light projecting unit 4 and the laser light received by the light receiving unit 5 to calculate the distance to the object to be measured 14. Further, the distance detector 13 detects the position of the object 14 by combining the calculated distance to the object 14 and the scanning angle of the rotating mirror 10 detected by the angle detector 12. ing.

  Next, the operation of the DUT 1 configured as described above will be described.

  The laser light having a substantially conical radiation shape with an elliptical cross-sectional shape emitted from the light projecting unit 4 becomes a substantially conical radiation shape with a circular cross-sectional shape at the cylindrical lens 7. The wavefront of the laser beam is parallel to the vertical direction. Most of the laser light is reflected upward in the vertical direction by the polarization beam splitter 6 and then introduced into the λ / 4 plate 8. The laser beam that has passed through the λ / 4 plate 8 is, for example, circularly polarized light that rotates in the right direction with respect to the radiation direction. This laser light is incident on the convex lens 9, and the radiation form is converted from a conical shape to a cylindrical shape by the convex lens 9. Then, the laser beam indicating the cylindrical radiation pattern is incident on the rotary mirror 10 vertically upward, and then reflected by the rotary mirror 10 in the horizontal direction. At this time, since the rotary mirror 10 is rotationally driven by the rotary drive unit 11 and is rotated at a high speed, the laser beam emitted from the light projecting unit 4 and reflected in the horizontal direction by the rotary mirror 10 is as shown in FIG. In addition, the scanning is continuously performed, for example, in a scanning region around 360 degrees around the optical axis Y through the light projecting / receiving window 2 of the housing 3.

  The laser beam reflected and returned by the measurement object 14 in the scanning region is circularly polarized light that rotates in the left direction with respect to the traveling direction of the light. Such laser light is introduced into the housing 3 through the light projecting / receiving window 2 and is incident on the rotating mirror 10 from a substantially horizontal direction. Thereafter, the light is reflected vertically downward by the rotating mirror 10 and is again introduced into the λ / 4 plate 8 while being focused into a substantially conical radiation form by the convex lens 9. Since the reflected light introduced into the λ / 4 plate 8 is a left-handed circularly polarized wave opposite to the radiated light, the reflected light transmitted through the λ / 4 plate 8 has a linear polarization plane of the radiated light. The light has orthogonal linear polarization planes. Therefore, this light is transmitted without being reflected by the polarization beam splitter 6 and received by the light receiving unit 5. The distance detection unit 13 compares the laser light emitted from the light projecting unit 4 with the laser light received by the light receiving unit 5 and calculates the distance to the object to be measured 14. The position of the DUT 14 is detected based on the scanning angle of the rotating mirror 10 detected by the above.

  As described above, according to the DUT 1 according to the present embodiment, the laser light diffusely emitted from the light projecting unit 4 has a substantially cross-sectional shape orthogonal to the optical axis X by the cylindrical lens 7. After being shaped into a circular shape and passing through the convex lens 9, it is converted into a cylindrical radial form that goes straight in parallel with the effective cross-sectional shape of the convex lens 9. Therefore, if the laser beam having such a cylindrical radiation form is scanned around by the rotating mirror 10, even if there is an obstacle such as dust on the optical path of the laser light, the influence of the obstacle is greatly increased. Thus, it is possible to reliably detect the object to be measured 14 as a detection target. In addition, the laser beam reflected by the object to be measured 14 passes through the same convex lens 9 as the laser beam emitted from the light projecting unit 4, and then reliably reaches the light receiving unit 5 through the polarization beam splitter 6. Therefore, even when the device under test 14 is present at a short distance, the device under test 14 can be easily detected.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the above-described embodiment, an example in which the convex lens 9 is disposed between the polarization beam splitter 6 and the rotating mirror 10 is illustrated. However, the convex lens 9 is attached to the position of the light projecting / receiving window 2 of the housing 3, and the housing 3 may be configured to rotate integrally with the rotating mirror 10.

  In the above-described embodiment, the scanning-type measurement object detection device that scans the laser light emitted from the light projecting unit 4 around the rotation mirror 10 is exemplified. However, the measurement object 14 to be detected is detected. Depending on the situation, the rotating mirror 10 is fixed at a predetermined scanning angle, or the rotating mirror 10 itself is omitted, and laser light is projected only in a predetermined direction, and reflected by the measurement object 14 existing in that direction. The laser beam may be received so as to be a non-scanning type object detection device.

  Further, the method for measuring the distance to the DUT 14 in the above embodiment is not particularly limited. For example, the distance measuring light emitted from the light projecting unit 4 is intensity-modulated into an isolated pulse, A TOF (Time Of Flight) method for obtaining a distance from the time difference from when the laser beam is emitted from the light projecting unit 4 to when the laser beam is received by the light receiving unit 5, or from the light projecting unit 4. AM that obtains the distance to the DUT 14 from the phase difference between the laser light emitted from the light projecting unit 4 and the laser light received by the light receiving unit 5 (Amplitude Modulation) method, ranging light emitted from the light projecting unit 4 is wavelength-modulated in the form of a triangular wave, and ranging light emitted from the light projecting unit 4 and distance measuring light received by the light receiving unit 5 Interference light frequency with It can be applied without problems such as FM (Frequency Modulation) method for determining the distance from the signal to the measured object 14.

It is a schematic longitudinal cross-sectional view which shows the whole structure of the to-be-measured object detection apparatus which concerns on one Embodiment of this invention. It is a schematic longitudinal cross-sectional view which shows an example of the conventional to-be-measured object detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measured object detection apparatus 2 Light projection / reception window 3 Housing 4 Light projection part 5 Light reception part 6 Polarizing beam splitter 7 Cylindrical lens 8 λ / 4 plate 9 Convex lens 10 Rotation mirror 11 Rotation drive part 12 Angle detection part 13 Distance detection part

Claims (6)

A radiation means for diffusingly emitting pulsed electromagnetic waves;
First radiation form converting means for converting the radiation form of the electromagnetic wave diffusively radiated from the radiation means into a parallel straight radiation form;
A receiving means for irradiating the object to be measured with the electromagnetic wave converted by the first radiation form converting means and receiving the electromagnetic wave reflected from the object to be measured via the first radiation form converting means;
The electromagnetic wave radiated from the radiating means is converted to the first radiation form between the radiating means and the first radiating means converting means and between the receiving means and the first radiating means converting means. Demultiplexing means for guiding the electromagnetic wave reflected from the object to be measured from the first radiation form converting means to the wave receiving means,
A distance detecting means for comparing the electromagnetic wave radiated from the radiating means with the electromagnetic wave received by the receiving means to detect the distance from the radiating means or the receiving means to the object to be measured; A device for detecting an object to be measured.   A cross section that is arranged between the radiating means and the demultiplexing means or between the demultiplexing means and the first radiation form converting means and is orthogonal to the wave axis of the electromagnetic wave that has passed through the first radiation form converting means. The device for detecting an object to be measured according to claim 1, further comprising second radiation form conversion means for shaping the electromagnetic wave diffusively radiated from the radiation means so that the shape is circular.   3. A wavefront control unit that is disposed between the radiation unit and the first radiation form conversion unit and controls a wavefront of an electromagnetic wave reflected by the object to be measured. 2. A device for detecting an object to be measured. Reflecting means disposed between the demultiplexing means and the object to be measured, and reflecting electromagnetic waves radiated through the demultiplexing means in a predetermined direction;
Rotation driving means for rotationally driving the reflecting member around the wave axis of the electromagnetic wave reaching the reflecting member through the branching means;
Angle detecting means for detecting the angular position of the reflecting member;
The said distance detection means detects the position of the said to-be-measured object based on the distance to the to-be-measured object, and the angular position of the said reflection member, The one of Claims 1-3 characterized by the above-mentioned. Device to be measured.   The device under test according to claim 1, wherein the outermost portion is covered with a housing having a transmission window that transmits electromagnetic waves. The device under test according to claim 1, wherein the electromagnetic wave radiated from the radiating means is a laser beam or a radio wave.

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