JP2016017803A - Optical monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical monitoring device that can reduce the size of the entire device and increase efficiency of light utilization.SOLUTION: An optical monitoring device 1 includes: a transmission light transmitting unit 11 transmitting a transmission light Y; a transmission light receiving unit 12 receiving a reflecting light Z of the transmission light Y reflected by an object X; light dividing means 13 with a transmission light reflecting region 13a reflecting the transmission light Y and transmitting the light Y to the object X and a reflecting light penetrating region 13b allowing the reflecting light Z to penetrate the region 13b and transmitting the light Z to the transmission light receiving unit 12; and a transmission/receiving light unit 14 providing the transmission light Y with a predetermined spread angle and transmitting the light Y to the object X while collecting the reflecting light Z from the object X, the transmission light transmitting unit 11 applying the transmission light Y to the transmission light reflecting region 13a of the dividing means 13.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical monitoring apparatus, and more particularly to an optical monitoring apparatus that can monitor or search an object simply and efficiently.

  2. Description of the Related Art Conventionally, there has been proposed a laser monitoring device that irradiates a monitoring field with a laser beam to search for maritime victims, maritime distress ships, and the like (see, for example, Patent Document 1). This laser monitoring device reflects laser light emitted from a laser light transmitting unit toward an object with a half mirror, and transmits reflected light of the laser light reflected from the object with a half mirror to receive laser light. Received in the department. Thereby, the optical axis of the transmitted light of the laser light and the optical axis of the reflected light can be matched, so that the configuration of the laser monitoring device can be simplified.

JP 2007-218807 A

  By the way, in the laser monitoring apparatus described in Patent Document 1, the laser beam on the transmission side is reflected using the half mirror and the reflected light of the laser beam on the reception side is transmitted. Thus, 50% of light loss occurs, and the light utilization efficiency of the laser monitoring device is 25%. Therefore, there is a demand for an optical monitoring apparatus that can reduce the size of the entire apparatus and improve the light utilization efficiency.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optical monitoring apparatus that can reduce the size of the entire apparatus and that can improve light utilization efficiency.

  The optical monitoring device of the present invention includes a transmission light transmission unit that transmits transmission light, a transmission light reception unit that receives reflected light of the transmission light reflected by an object, and the object that reflects the transmission light and reflects the transmission light. A transmission light reflecting area for transmitting to the transmission light, and a light separating means having a reflected light transmission area for transmitting the reflected light and transmitting it to the transmission light receiving unit, and providing a predetermined divergence angle to the transmission light and the object. A transmission / reception light unit that collects the reflected light from the object and transmits the transmission light to the transmission light reflection region of the light separating means. It is characterized by irradiating light.

  According to this configuration, since the transmission light and the reflected light can be separated by the light separation means, the transmission / reception light unit can be shared for transmission / reception, and the entire apparatus can be reduced in size. In addition, since the light receiving optical path of the reflected light from the object is shielded only by the transmission light reflection area, which is a partial area of the light separating means, the transmission light and the reflected light are irradiated by irradiating the entire surface of the half mirror with the transmission light. It is possible to reduce the amount of light loss compared to the case of separating the light. Therefore, it is possible to reduce the size of the entire apparatus and realize an optical monitoring apparatus that can improve the light utilization efficiency.

  In the optical monitoring device according to the aspect of the invention, it is preferable that the light separating unit totally reflects the transmission light in the transmission light reflection region. With this configuration, the amount of transmission light loss can be reduced, so that the light utilization efficiency can be further improved.

  The optical monitoring device of the present invention includes a transmission light transmission unit that transmits transmission light, a transmission light reception unit that receives reflected light of the transmission light reflected by an object, and the object that transmits the transmission light and transmits the transmission light. A transmission light transmitting area for transmitting to the transmission light, and a light separating means having a reflected light reflection area for reflecting the reflected light and transmitting the reflected light to the transmission light receiving unit, and a predetermined divergence angle to the transmission light to give the object A transmission / reception light unit that collects the reflected light from the object and transmits the transmission light to the transmission light transmission region of the light separation means. It is characterized by irradiating light.

  According to this configuration, since the transmission light and the reflected light can be separated by the light separation means, the transmission / reception light unit can be shared for transmission / reception, and the entire apparatus can be reduced in size. In addition, since the amount of light loss of the reflected light from the object is only the reflected light that passes through the transmission light reflection region, the transmission light and the reflected light are separated by irradiating the entire surface of the half mirror with the transmission light. In comparison, the amount of light loss can be reduced. Therefore, it is possible to reduce the size of the entire apparatus and realize an optical monitoring apparatus that can improve the light utilization efficiency.

  In the optical monitoring apparatus according to the aspect of the invention, it is preferable that the light separating unit totally reflects the reflected light in the reflected light reflecting region. With this configuration, the loss amount of reflected light can be reduced, so that the light use efficiency can be further improved.

  The optical monitoring device of the present invention preferably includes a first optical member that is provided between the transmission / reception light unit and the light separation means and makes the reflected light substantially parallel light. With this configuration, the light receiving path of the reflected light entering the light separating means can be expanded, so that the amount of reflected light loss can be further reduced and the light utilization efficiency can be further reduced.

  In the optical monitoring device according to the aspect of the invention, it is preferable that the first optical member has a transmission light transmission region that transmits the transmission light. With this configuration, the transmission light can be incident on the transmission / reception light unit as parallel light.

  In the optical monitoring device of the present invention, the first optical member selectively transmits the transmission light having a specific wavelength in the transmission light transmission region with respect to other light having a wavelength other than the transmission light. It is preferable. With this configuration, transmission light can be selectively transmitted.

  The optical monitoring device of the present invention preferably includes a second optical member that is provided between the transmission light transmission unit and the light separation unit and controls a beam diameter of the transmission light. With this configuration, since the beam diameter of the transmission light can be controlled within a desired range, it is possible to control the expansion range of the transmission light transmitted from the transmission / reception light unit to the object.

  In the optical monitoring apparatus according to the aspect of the invention, it is preferable that the optical monitoring device includes an electro-optical element that is provided between the light separation unit and the transmission light reception unit and controls a polarization characteristic of the reflected light. With this configuration, the polarization characteristics of the reflected light received by the transmission light receiving unit can be controlled, so that the pulse of the reflected light can be controlled in the transmission light receiving unit, and the utilization efficiency of the transmission light can be improved.

  In the optical monitoring device of the present invention, it is preferable that the optical monitoring apparatus includes a first polarizing element that is provided between the transmission light transmission unit and the light separation unit and converts the transmission light from linearly polarized light to circularly polarized light. With this configuration, the transmitted light and the reflected light can be converted into circularly polarized light, so that the pulse of the reflected light can be controlled in the transmitted light receiving unit, and the utilization efficiency of the transmitted light can be improved.

  In the optical monitoring apparatus of the present invention, it is preferable that the optical monitoring apparatus includes a second polarizing element that is provided between the transmission light transmission unit and the light separation unit and converts the transmission light into desired polarization. With this configuration, since the transmission light can be converted into desired linearly polarized light, the pulse of the reflected light can be controlled in the transmission light reception unit, and the utilization efficiency of the transmission light can be improved.

  According to the present invention, it is possible to realize an optical monitoring apparatus in which the entire apparatus can be reduced in size and the light utilization efficiency can be improved.

FIG. 1 is a schematic diagram showing an outline of an optical monitoring apparatus according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing an outline of an optical monitoring apparatus according to the second embodiment of the present invention. FIG. 3 is a schematic diagram showing an outline of an optical monitoring apparatus according to the third embodiment of the present invention. FIG. 4 is a schematic diagram showing an outline of an optical monitoring apparatus according to the fourth embodiment of the present invention. FIG. 5 is a schematic diagram showing an outline of an optical monitoring apparatus according to the fifth embodiment of the present invention. FIG. 6 is a schematic diagram showing an outline of an optical monitoring apparatus according to the sixth embodiment of the present invention. FIG. 7 is a schematic diagram showing an outline of an optical monitoring apparatus according to the seventh embodiment of the present invention. FIG. 8 is a schematic diagram showing an outline of an optical monitoring apparatus according to the eighth embodiment of the present invention. FIG. 9 is a schematic diagram showing an outline of an optical monitoring apparatus according to the ninth embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited to each following embodiment, It can implement by changing suitably. Also, the following embodiments can be implemented in combination as appropriate. Moreover, the same code | symbol is attached | subjected to the component which is common in each embodiment, and duplication of description is avoided.

(First embodiment)
FIG. 1 is a schematic diagram showing an outline of an optical monitoring apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the optical monitoring device 1 according to the present embodiment transmits transmission light Y from the transmission light transmission unit 11 toward the object X, and transmits reflected light Z reflected from the object X. The optical monitoring device is capable of monitoring and searching for the object X simply and efficiently by receiving the light at the light receiving unit 12. The optical monitoring device 1 includes a transmission light transmission unit 11 disposed on a transmission light path, a light separation unit 13 disposed at a subsequent stage of the transmission light transmission unit 11, and a transmission / reception light disposed at a subsequent stage of the light separation unit 13. Unit 14 is provided. Further, in the optical monitoring device 1, the light separating unit 13 is disposed on the reception optical path after the transmission / reception light unit 14, and the transmission light receiving unit 12 is disposed after the light separating unit 13.

  The transmission light transmission unit 11 guides the transmission light Y from the light source to a predetermined irradiation position by the optical fiber 11a. Further, the transmission light transmission unit 11 emits the transmission light Y from the emission end 11b of the optical fiber 11a toward the transmission light reflection region 13a of the light separation means 13. As the transmission light Y, various kinds of light can be used within the range where the effects of the present invention are exhibited, and examples thereof include illumination light and laser light.

  The light separating means 13 includes a transmission light reflection region 13a that reflects the transmission light Y and a reflected light transmission region 13b that transmits the reflection light from the object X. The transmission light reflection region 13a reflects the transmission light Y emitted from the transmission light transmission unit 11 toward the transmission / reception light unit 14 and shields the reception light path from the object X. The reflected light transmission region 13 b transmits the reflected light Z that has entered from the transmission / reception light unit 14.

  The light separating means 13 is configured by, for example, arranging an optical component that reflects the transmitted light Y such as a half mirror and a reflecting mirror on a part of the surface of a transparent substrate such as transparent glass and resin material. Is done. In this case, in the light separating means 13, the region where the optical component that reflects the transmission light on the base material is provided becomes the transmission light reflection region 13 a, and the region other than the transmission light reflection region 13 a on the base material becomes the reflected light transmission region 13 b. . The transmission light reflection region 13a can also be provided by vapor-depositing a metal material or the like on the surface of the base material. In the present embodiment, it is preferable to reduce the area of the transmission light reflection region 13a from the viewpoint of reducing the loss due to shielding of the reflected light Z. For example, the area of the transmission light reflecting region 13a is preferably 20% or less, more preferably 10% or less with respect to the surface area of the light separating means 13.

  The transmission / reception light unit 14 includes a plurality of lens groups (not shown). The transmission / reception light unit 14 gives a predetermined divergence angle to the transmission light Y and transmits the transmission light (light transmission) to the object X. The transmission / reception light unit 14 collects the reflected light Z from the object X and irradiates the light separating means 13 with it.

  The transmission light receiving unit 12 includes an imaging camera provided with a lens and a monitor connected to the imaging camera. The transmission light receiving unit 12 receives the reflected light Z collected by the transmission / reception light unit 14 and transmitted through the light separating means 13.

  Next, the overall operation of the optical monitoring apparatus 1 according to the present embodiment will be described. The transmission light transmission unit 11 irradiates the transmission light Y from the predetermined position guided by the optical fiber 11 a toward the transmission light reflection region 13 a of the light separation unit 13. The transmission light Y is reflected toward the transmission / reception light unit 14 by the transmission light reflection region 13 a of the light separating means 13. Here, in the present embodiment, the transmission light transmission unit 11 irradiates the transmission light Y toward the transmission light reflection region 13 a provided in a part of the light separation means 13, so that the loss amount of the transmission light Y is reduced. It becomes possible to reduce.

  The transmission light Y reflected toward the transmission / reception light unit 14 is given a predetermined divergence angle by the transmission / reception light unit 14 and is irradiated to the object X as transmission light. The reflected light Z reflected by the object X is collected by the transmission / reception light unit 14 and applied to the light separating means 13. The reflected light Z is applied to the transmission light receiving unit 12 through the reflected light transmission region 13b, and a part thereof is shielded by the transmission light reflection region 13a. Here, in the present embodiment, since the transmission light reflection region 13a is provided in a part of the light separation means 13, the loss amount of the reflected light Z shielded by the transmission light reflection region 13a can be reduced. It becomes possible.

  As described above, according to the optical monitoring device 1 according to the present embodiment, since the transmission light Y and the reflected light Z can be separated by the light separation means 13, the transmission / reception optical unit 14 is shared for transmission / reception. It becomes possible to reduce the size of the entire apparatus. In addition, since the reception optical path of the reflected light Z from the object X is shielded only by the transmission light reflection region 13a that is a partial region of the light separating means 13, the entire surface of the half mirror is irradiated with the transmission light Y for transmission. Compared with the case where the light Y and the reflected light Z are separated, the amount of light loss can be reduced. Therefore, it is possible to realize the optical monitoring apparatus 1 that can reduce the size of the entire apparatus and improve the light utilization efficiency.

(Second Embodiment)
FIG. 2 is a schematic diagram showing an outline of the optical monitoring device 2 according to the second embodiment of the present invention. As shown in FIG. 2, in addition to the configuration of the optical monitoring device 1 according to the first embodiment described above, the optical monitoring device 2 according to the present embodiment is provided at the subsequent stage of the light separating means 13 on the transmission optical path. A collimating lens (optical member) 21 is provided in front of the transmission / reception light unit 14. The collimating lens 21 has a function of making the reflected light Z, which is collected by the transmission / reception light unit 14 and irradiated toward the light separating means 13, substantially parallel light. The collimating lens 21 has an area corresponding to the receiving surface of the transmission light receiving unit 12 (for example, the entire surface of the lens of the imaging camera). Since other configurations are the same as those of the optical monitoring device 1 according to the first embodiment described above, description thereof is omitted.

  Next, the overall operation of the optical monitoring apparatus 2 according to the present embodiment will be described focusing on the differences from the optical monitoring apparatus 1 described above. The reflected light Z reflected by the object X enters the collimating lens 21 while being collected by the transmission / reception light unit 14, and the optical path is aligned with substantially parallel light. Here, in the present embodiment, since the reflected light Z is made substantially parallel light by the collimating lens 21, the reflected light Z is condensed on the light separating means 13 while being condensed by the transmission / reception light unit 14 without providing the collimating lens 21. Compared with the case of irradiation, the irradiation area A1 of the reflected light Z with respect to the reflected light transmission region 13b of the light separating means 13 can be enlarged. In addition, since the collimating lens 21 has an area corresponding to the receiving surface of the transmission light receiving unit 12, it is possible to irradiate the reflected light Z to the maximum range of the transmission light receiving unit 12. Therefore, the loss amount of the reflected light Z can be further reduced.

  In the present embodiment, the example in which the collimator lens 21 is used as the optical member that makes the reflected light Z substantially parallel light has been described. However, the optical member is particularly capable of making the reflected light Z substantially parallel light. It is not limited.

(Third embodiment)
FIG. 3 is a schematic diagram showing an outline of the optical monitoring device 3 according to the third embodiment of the present invention. As shown in FIG. 3, the optical monitoring device 3 according to the present embodiment includes a light separation means 22 having an opening instead of the light separation means 13 of the optical monitoring device 2 according to the second embodiment described above. Prepare. In this light separating means 22, the opening becomes a transmission light transmission region 22 a that transmits the transmission light Y, and the surface other than the opening reflects the reflected light Z toward the transmission light reception unit 12. Become. As the light separation means 22, for example, a reflection mirror and a half mirror provided with an opening through which the transmission light Y is transmitted can be used. In addition, the light separating means 22 is configured by disposing an optical component that reflects transmission light, such as a half mirror and a reflecting mirror, on a part of the surface of a transparent substrate such as transparent glass and resin material. Is done. In this case, in the light separating means 22, the region where the optical component that reflects the transmission light on the base material is provided becomes the reflected light reflection region 22b, and the region other than the reflected light reflection region 22b on the base material becomes the transmission light transmission region 22a. . The reflected light reflecting region 22b can also be provided by evaporating a metal material or the like on the surface of the substrate.

  In the present embodiment, it is preferable to reduce the area of the transmission light transmission region 22a from the viewpoint of reducing loss due to transmission of the reflected light Z. For example, the area of the transmission light transmission region 22a is preferably 20% or less, and more preferably 10% or less, with respect to the surface area of the light separation means 22. In the present embodiment, the example in which the opening is provided and the transmission light transmission region 22a is provided has been described. However, the present invention is not limited to this configuration. For example, the transmission light transmission region 22a selectively transmits the transmission light Y having a specific wavelength with respect to other light such as the reflection light Z having a wavelength region other than the specific wavelength, as compared with the reflection light reflection region 22b. You may comprise so that it may permeate | transmit. Even if comprised in this way, since the transmission light Y can be selectively permeate | transmitted and transmitted with respect to the target object X, the utilization efficiency of the transmission light Y improves. Since other configurations are the same as those of the optical monitoring device 2 according to the second embodiment described above, description thereof is omitted.

  Next, the overall operation of the optical monitoring apparatus 3 according to the present embodiment will be described focusing on differences from the optical monitoring apparatus 2 described above. The transmission light transmission unit 11 irradiates the transmission light Y from the predetermined position guided by the optical fiber 11 a toward the transmission light transmission region 22 a of the light separation unit 22. The transmission light Y is irradiated toward the transmission / reception light unit 14 via the transmission light transmission region 22a of the light separation means 22. Here, in the present embodiment, since the transmission light Y having a small beam diameter guided by the optical fiber 11a is irradiated toward the transmission light transmission region 22a provided in a part of the light separation means 22, the transmission light Y It is possible to reduce the amount of loss.

  The reflected light Z reflected by the object X is collected by the transmission / reception light unit 14 and applied to the light separating means 22. The reflected light Z is applied to the transmission light receiving unit 12 through the reflected light reflection region 22b, and part of the reflected light Z is transmitted through the transmission light transmission region 22a. Here, in the present embodiment, since the transmission light transmission region 22a is provided in a part of the light separation means 22, it is possible to reduce the loss amount of the reflected light Z transmitted through the transmission light transmission region 22a. Become.

(Fourth embodiment)
FIG. 4 is a schematic diagram showing an outline of the optical monitoring device 4 according to the fourth embodiment of the present invention. As shown in FIG. 4, in addition to the configuration of the optical monitoring device 3 according to the third embodiment described above, the optical monitoring device 4 according to the present embodiment is provided at the subsequent stage of the light separating means 22 on the transmission optical path. In addition, a collimating lens (optical member) 23 having an opening 23 </ b> A disposed in front of the transmission / reception light unit 14 is provided. The collimating lens 23 has a function of making the reflected light Z, which is collected by the transmission / reception light unit 14 and radiated toward the light separating means 22, substantially parallel light. The collimating lens 23 has an area corresponding to the receiving surface of the transmission light receiving unit 12 (for example, the entire surface of the lens of the imaging camera). Other configurations are the same as those of the optical monitoring device 3 according to the third embodiment described above, and thus the description thereof is omitted.

  Next, the overall operation of the optical monitoring device 4 according to the present embodiment will be described focusing on the differences from the optical monitoring device 3 described above. The transmission light Y reflected toward the transmission / reception light unit 14 is irradiated to the transmission / reception light unit 14 as parallel light through the opening 23 </ b> A of the collimator lens 23. The reflected light Z reflected by the object X is collected by the transmission / reception light unit 14 and applied to the light separating means 22. The reflected light Z reflected by the object X enters the collimating lens 23 while being collected by the transmission / reception light unit 14, and the optical path is aligned with substantially parallel light. Here, in the present embodiment, the transmission light Y is transmitted to the transmission / reception light unit 14 through the opening 23A of the collimating lens 23, so that the collimating lens 23 is compared with the case where the opening 23A is not provided. Thus, it is possible to avoid surface reflection of the transmission light Y at the collimating lens 23 and attenuation of the transmission light Y from the collimating lens 23 that occur when the light passes through the beam. In addition, since the transmission light Y is transmitted through the opening 23A, surface reflection at the collimating lens 23 can be prevented, so that scattering of the transmission light Y can also be suppressed. Therefore, the loss amount of the transmission light Y can be further reduced.

(Fifth embodiment)
FIG. 5 is a schematic diagram showing an outline of the optical monitoring device 5 according to the fifth embodiment of the present invention. As shown in FIG. 5, the optical monitoring device 5 according to the present embodiment is a subsequent stage of the transmission light transmission unit 11 in the transmission light path in addition to the configuration of the optical monitoring device 1 according to the first embodiment described above. And a molded lens 15 disposed in front of the light separating means 13. The shaping lens 15 shapes the transmission light Y into a desired beam diameter. Since other configurations are the same as those of the optical monitoring device 1 according to the first embodiment described above, description thereof is omitted.

  Next, the overall operation of the optical monitoring apparatus 5 according to the present embodiment will be described focusing on differences from the optical monitoring apparatus 1 described above. The transmission light Y emitted from the transmission light transmission unit 11 is shaped into a desired beam diameter by the shaping lens 15 and then reflected toward the transmission / reception light unit 14 by the transmission light reflection region 13 a of the light separation means 13. Thereby, for example, the optical monitoring device 5 can adjust the transmission light to the beam diameter in accordance with the angle of view of the lens of the imaging camera of the transmission light receiving unit 12. Further, the optical monitoring device 5 can also shape the transmission light Y to a beam diameter corresponding to the area of the transmission light reflection region 13a of the light separating means 13.

(Sixth embodiment)
FIG. 6 is a schematic diagram showing an outline of the optical monitoring device 6 according to the sixth embodiment of the present invention. As shown in FIG. 6, the optical monitoring device 6 according to the present embodiment includes an optical separating unit 22 and a transmission light receiving unit 12 in addition to the configuration of the optical monitoring device 3 according to the third embodiment described above. An electro-optic element 24 is disposed therebetween. The electro-optic element 24 includes an element composed of a dielectric isotropic crystal having piezoelectricity and a polarizing plate. When a predetermined voltage is applied, the refractive index of the element changes. The electro-optic element 24 controls the polarization direction of the reflected light Z irradiated to the transmission light receiving unit 12 to a desired polarization direction by applying a predetermined voltage. The electro-optic element 24 is configured so that when the linearly polarized transmission light Y from the transmission light transmitting unit 11 enters the transmission light receiving unit 12, the linearly polarized light of the transmission light Y is orthogonal to the polarization direction of the polarizing plate. By changing, the transmission light Y is prevented from entering the transmission light receiving unit 12. In addition, when the reflected light Z from the object X enters the transmission light receiving unit 12, the electro-optic element 24 does not control the polarization direction of the reflected light Z, and the reflected light Z passes through the polarizing plate. In this way, the transmission light receiving unit 12 can receive light. Other configurations are the same as those of the optical monitoring device 3 according to the third embodiment described above, and thus the description thereof is omitted.

  Next, the overall operation of the optical monitoring apparatus 6 according to the present embodiment will be described focusing on the differences from the optical monitoring apparatus 3 described above. The reflected light Z reflected by the object X is reflected by the reflected light reflecting region 22 b and is applied to the transmission light receiving unit 12 via the electro-optic element 24. Here, in the present embodiment, by applying a voltage to the electro-optical element 24, the transmission light Y irradiated from the transmission light transmitting unit 11 is polarized in the direction orthogonal to the polarizing plate by the electro-optical element 24. By being changed to, it is blocked by the polarizing plate of the electro-optic element 24 and can be prevented from entering the transmission / reception unit 12. In addition, the reflected light Z from the object X is received without being blocked by the polarizing plate of the electro-optic element 24 without being controlled by the electro-optic element 24. Thus, it is possible to control the pulse of the reflected light Z irradiated to the transmission light receiving unit 12, and the utilization efficiency of the transmission light Y is improved.

(Seventh embodiment)
FIG. 7 is a schematic diagram showing an outline of the optical monitoring device 7 according to the seventh embodiment of the present invention. As shown in FIG. 7, the optical monitoring device 7 according to the present embodiment includes a transmission light transmission unit 11 and a light separation unit 22 in addition to the configuration of the optical monitoring device 6 according to the sixth embodiment described above. A quarter-lambda element (first polarizing element) 25 is provided between them. The ¼λ element 25 converts the phase of the polarization of the transmission light Y and converts the linearly polarized light into circularly polarized light. Since other configurations are the same as those of the optical monitoring apparatus 6 according to the sixth embodiment described above, description thereof is omitted.

  Next, the overall operation of the optical monitoring device 7 according to the present embodiment will be described focusing on the differences from the optical monitoring device 6 described above. The linearly polarized transmission light Y emitted from the transmission light transmitting unit 11 is converted from linearly polarized light to circularly polarized light by the ¼λ element 25 and irradiated toward the transmission / reception light unit 14. On the other hand, the linearly polarized reflected light Z reflected by the object X is collected by the transmission / reception light unit 14 and enters the transmission light receiving unit 12 via the electro-optic element 24. Here, in the present embodiment, the transmission light Y that is irradiated after being converted into circularly polarized light by the ¼λ element 25 is polarized light whose polarization of the transmission light Y is orthogonally crossed from the circularly polarized light by the electro-optic element 24. Since the direction is changed to linearly polarized light, the incidence on the transmission light receiving unit 12 is suppressed. The reflected light Z from the object X is controlled so that the reflected light Z is transmitted through the polarizing plate of the electro-optic element 24 by not controlling the polarization direction by the electro-optic element 24. 12, the light can be received. Thus, it is possible to control the pulse of the reflected light Z irradiated to the transmission light receiving unit 12, and the utilization efficiency of the transmission light Y is improved.

(Eighth embodiment)
FIG. 8 is a schematic diagram showing an outline of the optical monitoring device 8 according to the eighth embodiment of the present invention. As shown in FIG. 8, in addition to the configuration of the optical monitoring device 6 according to the sixth embodiment described above, the optical monitoring device 8 according to the present embodiment includes a transmission light transmitter 11 and a light separating unit 22. The polarizing plate (second polarizing element) 26 is disposed between the two. The polarizing plate 26 converts the transmitted light Y into a desired polarized light. Since other configurations are the same as those of the optical monitoring apparatus 6 according to the sixth embodiment described above, description thereof is omitted.

  Next, the overall operation of the optical monitoring apparatus 8 according to the present embodiment will be described focusing on the differences from the optical monitoring apparatus 6 described above. The linearly polarized transmission light Y emitted from the transmission light transmission unit 11 is converted into a desired polarization direction different from the reflected light Z by the polarizing plate 26 and irradiated to the object X. On the other hand, the linearly polarized reflected light Z reflected by the object X is irradiated to the transmission light receiving unit 12 without changing the polarization direction. Here, in the present embodiment, by applying a voltage to the electro-optical element 24, the transmission light Y irradiated from the transmission light transmitting unit 11 via the polarizing plate 26 is polarized by the electro-optical element 24. By changing in the direction orthogonal to the polarizing plate, the electro-optical element 24 is blocked by the polarizing plate, and the incidence on the transmission / reception unit 12 is suppressed. In addition, the reflected light Z from the object X is received without being blocked by the polarizing plate of the electro-optic element 24 without being controlled by the electro-optic element 24. Thus, it is possible to control the pulse of the reflected light Z irradiated to the transmission light receiving unit 12, and the utilization efficiency of the transmission light Y is improved.

(Ninth embodiment)
FIG. 9 is a schematic diagram showing an outline of an optical monitoring device 9 according to the ninth embodiment of the present invention. As shown in FIG. 9, in addition to the configuration of the optical monitoring device 8 according to the eighth embodiment described above, the optical monitoring device 9 according to the present embodiment includes an optical separation unit 22 and a transmission / reception light unit 14. A quarter-lambda element (first polarizing element) 25 is provided between them. Other configurations are the same as those of the optical monitoring device 8 according to the eighth embodiment described above, and thus the description thereof is omitted.

  Next, the overall operation of the optical monitoring device 9 according to the present embodiment will be described focusing on differences from the optical monitoring devices 6 to 8 described above. The linearly polarized transmission light Y emitted from the transmission light transmission unit 11 is converted into a desired polarization direction different from the reflected light Z by the polarizing plate 26, and converted from linearly polarized light to circularly polarized light by the ¼λ element 25. Irradiated toward the transmission / reception light unit 14. On the other hand, the reflected light Z reflected by the object X is reflected by the reflected light reflecting region 22 b and is applied to the transmission light receiving unit 12 via the electro-optic element 24. Here, in the present embodiment, by applying a voltage to the electro-optic element 24, the transmission irradiated from the transmission light transmission unit 11 toward the object X through the polarizing plate 26 and the ¼λ element 25. The light Y is blocked by the polarizing plate of the electro-optic element 24 by changing the polarization direction in the direction orthogonal to the polarizing plate by the electro-optic element 24, and the incidence to the transmission / reception unit 12 is suppressed. In addition, the reflected light Z from the object X is received without being blocked by the polarizing plate of the electro-optic element 24 without being controlled by the electro-optic element 24. Thus, it is possible to control the pulse of the reflected light Z irradiated to the transmission light receiving unit 12, and the utilization efficiency of the transmission light Y is improved.

DESCRIPTION OF SYMBOLS 1-9 Optical monitoring apparatus 11 Transmission light transmission part 11a Optical fiber 11b Emission end 12 Transmission light receiving part 13 Light separation means 13a Transmission light reflection area 13b Reflection light transmission area 14 Transmission / reception light unit 15 Molding lens 21, 23 Collimating lens (Optical) Element)
22 Light separating means 22a Transmitted light transmission region 22b Reflected light reflection region 24 Electro-optic element 25 1 / 4λ element 26 Polarizing plate X Target object Y Transmitted light Z Reflected light

Claims (11)

A transmission light transmitter for transmitting the transmission light;
A transmission light receiving unit that receives the reflected light of the transmission light reflected by the object;
A light separation means having a transmission light reflection region that reflects the transmission light and transmits it to the object, and a reflected light transmission region that transmits the reflection light and transmits the transmission light to the transmission light receiver;
A transmission / reception light unit that gives the transmission light a predetermined divergence angle and transmits the transmission light to the object, and condenses the reflected light from the object; and
The optical monitoring device, wherein the transmission light transmission unit irradiates the transmission light to the transmission light reflection region of the light separation means.   The optical monitoring apparatus according to claim 1, wherein the light separation unit totally reflects the transmission light in the transmission light reflection region. A transmission light transmitter for transmitting the transmission light;
A transmission light receiving unit that receives the reflected light of the transmission light reflected by the object;
A light separating means having a transmission light transmission region that transmits the transmission light and transmits the transmission light to the object, and a reflected light reflection region that reflects the reflected light and transmits the reflected light to the transmission light reception unit;
A transmission / reception light unit that gives the transmission light a predetermined divergence angle and transmits the transmission light to the object, and condenses the reflected light from the object; and
The optical monitoring device, wherein the transmission light transmission unit irradiates the transmission light to the transmission light transmission region of the light separation means.   The optical monitoring device according to claim 3, wherein the light separating unit totally reflects the reflected light in the reflected light reflecting region.   The optical according to any one of claims 1 to 4, further comprising a first optical member that is provided between the transmission / reception light unit and the light separating unit and makes the reflected light substantially parallel light. Monitoring device.   The optical monitoring device according to claim 1, wherein the first optical member has a transmission light transmission region that transmits the transmission light.   The optical monitoring according to claim 6, wherein the first optical member selectively transmits the transmission light having a specific wavelength in the transmission light transmission region with respect to other light having a wavelength other than the transmission light. apparatus.   8. The apparatus according to claim 1, further comprising a second optical member that is provided between the transmission light transmission unit and the light separating unit and controls a beam diameter of the transmission light. 9. Optical monitoring device.   9. The optical monitoring according to claim 1, further comprising an electro-optic element that is provided between the light separation unit and the transmission light reception unit and controls a polarization characteristic of the reflected light. 10. apparatus.   10. The apparatus according to claim 1, further comprising a first polarizing element that is provided between the transmission light transmission unit and the light separation unit and converts the transmission light from linearly polarized light to circularly polarized light. The optical monitoring device described in 1.   11. The apparatus according to claim 1, further comprising: a second polarizing element that is provided between the transmission light transmission unit and the light separation unit and converts the transmission light into a desired polarization. Optical monitoring device.

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