JP2006250603A - Sensing method and sensing device by photosensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely detect the presence or absence of a body to be detected in a detection region that is clean and is under a high-temperature environment. <P>SOLUTION: An opening 2 is provided on a sidewall 1a of a quartz box 1, and a pipe-like member 6 for connection is mounted so that it passes through the opening 2. In the member 6 for connection, the base end section of a quartz glass member 3c that is formed in a slenderly cylindrical shape and is arranged so that the tip section reaches an area near the detection region 4 in the quartz box 1, and the tip section of a parallel type optical fiber 17 of a reflection type optical fiber sensor 8 is mounted. Light 13 guided via an optical fiber wire 10 for light projection of the parallel type optical fiber 17 is guided to an area near the detection region 4 through the quartz glass member 3c with low loss for projecting toward the detection region 4. Reflected light 13a occurring when the object 5 to be detected exists in the detection region 4 is received by the tip surface of the quartz glass member 3c near the detection region, is guided inside the quartz glass member 3c while the loss is small, and is received by an optical fiber wire 12 for receiving light. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention projects light from a light projecting unit of a photosensor to a required detection region, and changes the amount of light received from the detection region to the light receiving unit of the photosensor. The present invention relates to a sensing method and apparatus using an optical sensor for detecting presence or absence and behavior.

  In general, in various manufacturing sites, etc., it is possible to detect whether or not the workpiece is placed at a predetermined position, or to detect where the workpiece is located. As a technology for detecting the presence or absence of light, there is a sensing technology in which detection of an object to be detected is performed using light as a medium. As a device used in this type of sensing technology, for example, a light source such as a light emitting diode is used. A light projecting unit for projecting light toward the required detection region, and a light receiving unit for receiving light from the detection region and inputting the light to a photodetector such as a photodiode. In a state where light is projected from the light projecting unit to the detection region, a light sensor configured to detect the presence or absence of the detection target in the detection region based on the change in the amount of light received from the detection region to the light receiving unit. (Photoelectric switch) is widely known. As such an optical sensor, there are three types of sensors of a reflection type, a transmission type, and a reflection regression type according to the type of light received by the light receiving unit in order to detect the detection target.

  That is, the reflection type optical sensor has a configuration in which the light projecting unit and the light receiving unit are arranged side by side so as to face a required detection region. As a result, when the light output from the light source is projected from the light projecting unit toward the detection area, the projected light is simply dissipated when there is no object to be detected in the detection area. Therefore, the light is hardly incident on the light receiving portion. On the other hand, when an object to be detected exists in the detection area, the light projected from the light projecting unit toward the detection area is regularly reflected or scattered by the object to be detected existing in the detection area. Since the reflected light is received by the light receiving unit and detected by the photodetector, the amount of received light is increased. Therefore, the presence / absence of the detection object in the detection region can be detected based on whether or not the amount of light received by the light receiving unit increases from the initial state.

  The transmission type optical sensor has a configuration in which a light projecting unit and a light receiving unit are installed so as to face each other with a required detection area interposed therebetween. As a result, when the light output from the light source is projected from the light projecting unit toward the light receiving unit facing the detection region, the light projecting unit does not exist in the detection region. The light projected from the light section passes (transmits) through the detection region without being blocked, is received by the light receiving section, and is detected by the photodetector. On the other hand, when the detected object is present in the detection area, the light projected from the light projecting unit is blocked by the detected object when the detected object does not pass the light. When it becomes impossible to reach the light receiving section, and when the detected object is translucent or scatters light, the amount of light received by the light receiving section is reduced. Therefore, the presence / absence of the detection object in the detection region can be detected based on whether or not the amount of light received by the light receiving unit decreases from the initial state.

  The reflection regression type optical sensor has a light projecting unit and a light receiving unit arranged side by side so as to face a required detection region, and further, a mirror-like reflector is disposed between the light projecting unit and the light receiving unit across the detection region. A configuration is provided so as to face each other. As a result, when the light output from the light source is projected toward the detection region from the light projecting unit, the light projected from the light projecting unit is not present in the detection region. The light that passes through the detection region and reaches the reflection plate, is reflected by the reflection plate, passes through the detection region again, is received by the light receiving unit, and is detected by the photodetector. On the other hand, when the detection object is present in the detection area, the light path from the light projected from the light projecting unit to the light receiving unit after being reflected by the reflecting plate is blocked by the detected object. Therefore, the presence / absence of the detection object in the detection region can be detected based on the same principle as that of the transmission type optical sensor described above.

  In addition, as a kind of optical sensor of each of the reflection type, transmission type, and reflection regression type, optical fiber bases that are optical waveguides on the output side of the light source and the input side of the photodetector are the same as described above. The end side is connected so that the front end surface of the optical fiber can function as a light projecting part or a light receiving part. This allows the light projecting part and the light receiving part to be freely used even in a narrow place. Optical fiber sensors that can be installed are also widely known.

  That is, as a transmissive optical fiber sensor, for example, a sensor body having a light source such as a light emitting diode and a photodetector such as a photodiode is provided. Connect the proximal end of the two optical fibers for light projection and light reception to the input side, and connect the distal end of the optical fiber strand made of metal or resin to the distal end of the optical fiber for projection A light emitting side sensor head that can be held is attached, and a light receiving side sensor head similar to the light projecting side is attached to the tip of the light receiving optical fiber. Generally known is a configuration in which a head is installed so as to face each other across a required detection area. With this configuration, the light guided from the light source of the sensor main body through the light projecting optical fiber is converted into a front end surface (light projecting surface) of the light projecting optical fiber as a light projecting portion held by the light projecting side sensor head. Therefore, when light is projected toward the light receiving side sensor head across the detection area, light is projected from the light projecting surface of the light projecting optical fiber when no object to be detected exists in the detection area. The received light passes through the detection region without being blocked, and is received by the front end surface (light receiving surface) of the light receiving optical fiber as the light receiving portion held by the light receiving side sensor head. The light is transmitted to the light detector of the sensor body through the light receiving optical fiber and detected. On the other hand, when the detected object is present in the detection region, the light projected from the light projecting surface of the light projecting optical fiber is blocked by the detected object. Therefore, based on the same principle as the above-described transmission type optical sensor, based on whether or not the amount of light received by the light receiving surface of the light receiving optical fiber as the light receiving unit is reduced from the initial state, in the detection region. The presence or absence of the detected object can be detected.

  In addition, as a reflection type optical fiber sensor, the light projecting optical fiber and the light receiving optical fiber, each of which is connected to the sensor body at the base end side in the same manner as described above, are made of metal or resin, A light emitting / receiving integrated sensor head is attached so that the ends of the optical fibers for light projecting and receiving can be held close to each other in close proximity. There is a configuration in which it is installed so as to face the detection region at one side position in any of the front, rear, left and right directions. With this configuration, the light guided from the light source of the sensor body through the light projecting optical fiber is converted into a light projecting optical fiber front end surface (projecting light) as a light projecting unit held by the light projecting / receiving integrated sensor head. When light is projected toward the detection region from the light surface), the projected light is simply dissipated when there is no object to be detected in the detection region. The optical fiber for receiving light as a light receiving portion held by the sensor head is hardly incident on the front end surface (light receiving surface). On the other hand, when the detection target exists in the detection region, the light projected toward the detection region from the light projection surface of the light projecting optical fiber is detected in the detection region. The reflected light is received by the light receiving surface of the light receiving optical fiber, and the received light is transmitted to the light detector of the sensor body through the light receiving optical fiber and detected. Become so. Therefore, based on the same principle as that of the reflection type optical sensor described above, the amount of light received by the light receiving surface of the light receiving optical fiber as the light receiving unit is increased in the detection region based on whether or not the amount of light received from the initial state is increased. A device that can detect the presence or absence of a detection body has been proposed (see, for example, Patent Document 1).

  Further, as another type of reflection type optical fiber sensor, instead of a configuration in which a sensor head integrated with light projection and reception is mounted on the sensor body through two optical fibers for light projection and light reception, A plurality of receiving optical fiber strands are coaxially arranged around the optical fiber strand for light, and the projecting optical fiber strand and the receiving optical fiber strand are combined to form a coaxial type. There has also been proposed one in which a sensor head integrated with light transmission and reception is attached to the front end side of the optical fiber for light transmission and reception that is a single cable (for example, see Patent Document 2). In addition to the coaxial type, the optical fiber for projecting and receiving light and the light receiving optical fiber are combined into a single cable. A large number of optical fiber strands for light projection and light reception are arranged in a parallel type in which two optical fiber strands are arranged in parallel and covered together or in two semicircular regions divided into a circular cross section. A split type in which the optical fiber strands are arranged separately is also widely known.

  Further, as a reflection regression type optical fiber sensor, a sensor head comprising a light projecting part and a light receiving part similar to the light projecting / receiving integrated sensor head of the reflection type optical fiber sensor, and a mirror-like reflecting plate Are arranged so as to face each other with the required detection area interposed therebetween, and when the detection target does not exist in the detection area, the light projected from the light projecting portion of the sensor head passes through the detection area. It is generally known that the light reaching the reflecting plate and reflected by the reflecting plate passes through the detection region again and is received by the light receiving unit. According to this configuration, when the detection target exists in the detection area, the light path that is reflected by the reflection plate from the light projecting unit of the sensor head and reaches the light receiving unit is the detected object. Based on whether the amount of light received by the light receiving surface of the light receiving optical fiber as the light receiving portion increases from the initial state based on the same principle as the above-described reflection regression type optical sensor. Thus, the presence / absence of the detected object in the detection region can be detected.

  By the way, when heat-treating a workpiece in a high-temperature furnace, it is necessary to detect the presence or absence of a detection object such as a workpiece in a detection region in a high-temperature environment such as the inside of the high-temperature furnace. There is. In this case, as one of means for optically detecting the detection object in the high temperature environment such as the inside of the high temperature furnace, a window is provided in the furnace body of the high temperature furnace, and the normal environment is provided outside the furnace body. Outside the window, for example, the light projecting part and the light receiving part of the reflection type optical sensor described above are installed, or the light emitting and receiving integrated sensor head of the reflection type optical fiber sensor is installed, so that the detection area in the furnace body By detecting the presence or absence of reflected light from the detected object inside the furnace body in a high temperature environment through the window by projecting and receiving light through the window, the presence or absence of the detected object in the high temperature environment It is conceivable to detect this.

  As another method for optically detecting a detection object in a required detection region under a high temperature environment, a reflective optical fiber sensor is used to project the sensor body a as shown in FIG. A region of a required length near the light projecting / receiving integrated sensor head b in each of the light projecting and receiving optical fibers c to which the light receiving integrated sensor head b is connected is a fiber element made of glass ( A light-receiving optical sensor d formed by coating a fiber core wire with a jacket made of silicon or the like; The light emitting and receiving integrated sensor head b having the heat resistance is positioned near the required detection region in the high temperature environment, as having heat resistance that can withstand the high temperature environment of the detection region. I will face the detection area The light emitting and receiving heat-resistant optical fibers d are arranged from the position where the sensor head b is installed to the boundary wall e between the high temperature environment and the normal environment. As a configuration, it has been considered to directly detect and detect a detection object by directly projecting and receiving light on a detection region in a higher temperature environment than the above-described sensor head b. For example, see Patent Document 3).

  As shown in FIG. 12, the optical fiber imparted with heat resistance includes a carbon coating j, a base metal layer k, and a base metal layer k on the outer periphery of an optical fiber wire i composed of a core g and a cladding h. A metal-coated optical fiber f obtained by sequentially coating a thick metal layer 1 has also been proposed (see, for example, Patent Document 4). Reference numeral m denotes a metal sheath provided so that a required space n is formed on the outer periphery of the metal-coated optical fiber f.

  By the way, in a furnace used for heating a glass substrate or a wafer in the liquid crystal / semiconductor industry, for example, a furnace for annealing (firing) a glass substrate with a silicon film in manufacturing a liquid crystal panel (hereinafter simply referred to as an annealing furnace), the inside of the furnace is It becomes a very high temperature environment of 600-700 degreeC. Furthermore, in the above annealing furnace, if the inside of the furnace is contaminated by metal ions or dust generated from heat-resistant resin, etc., it will affect the quality of the product. Contamination such as dust generation is not preferable. Therefore, in the annealing furnace, the surface inside the furnace is usually made of a member made of a material that is free from the risk of metal contamination and dust generation typified by quartz glass. That is, the inside of the furnace is, for example, a quartz box (quartz chamber) whose inner surface is entirely covered with quartz glass, and further, in the quartz box, the glass substrate with a silicon film that is an object of heat treatment, When it is necessary to hold at the required height position, the quartz glass pins having a diameter of several millimeters are arranged from the bottom of the furnace, corresponding to the four corners of the glass substrate with silicon film to be held, A large number of such as the arrangement corresponding to the central portion are erected so that the required arrangement is obtained, and the glass substrate with the silicon film is placed on the upper side of each pin so that the inside of the furnace is made of the above metal. A clean environment free from contamination such as contamination and heat-resistant resin dust generation can be achieved.

JP 2001-221918 A JP-A-8-43629 Japanese Patent Application Laid-Open No. 2002-162312 JP-A-6-300944

  However, the presence or absence of an object to be detected in a detection region in a high-temperature environment such as the inside of a high-temperature furnace, the light projecting part and the light-receiving part of a reflective optical sensor installed outside the window provided in the furnace body of the high-temperature furnace, In the method of detecting by projecting and receiving light through a window from a sensor head integrated with a reflection type optical fiber sensor, the light projected from the sensor projecting unit is detected in the detection area. The light path when the reflected light is reflected by the body and received by the sensor light receiving unit passes through the window twice during light projection and light reception. Therefore, when the light projected from the sensor light projecting part toward the detection region passes through the window from the outside of the furnace to the inside of the furnace, and the reflected light from the detected object to be received passes through the window from the inside of the furnace to the furnace. When transmitting to the outside, scattering occurs. For this reason, since the light finally received by the sensor light receiving unit is light that has been scattered twice when passing through the window, the amount of light generated by the scattering of light when passing through the window Therefore, there is a problem that the amount of light detected by the photodetector of the reflection type optical sensor or the optical fiber sensor is lowered.

  In addition, even when using either the reflection type optical sensor or the optical fiber sensor, since the light projecting unit and the light receiving unit are both installed outside the furnace, the light projected toward the detection region, In addition, the reflected light from the detected object to be received must pass through a long space between the window of the furnace body and the detection area inside the high-temperature furnace. After passing through the window of the furnace body and passing through the space part to the detection area, and through the space part until the reflected light from the detected object to be received reaches the window from the detection area At this time, there is a possibility that noise is mixed under the influence of disturbance. Therefore, in the light finally received by the light receiving part of the optical sensor or the optical fiber sensor, the forward path (light path during light projection) and the return path (light path during light reception) from the window to the detection area inside the high temperature furnace. ), The S / N ratio of the light detected by the light detector of the reflection type optical sensor or the optical fiber sensor is lowered. There is a problem that detection accuracy is low.

  On the other hand, in order to detect the presence / absence of an object to be detected in a detection region under a high temperature environment, the heat-resistant optical fibers d and f as shown in Patent Document 3 and Patent Document 4 are disclosed in Patent Document 3. In the case of adopting a sensor head b that is integrated with a light projecting / receiving unit that can be placed in a high temperature environment such as this, and the sensor head b is installed in the furnace in the vicinity of the detection region, the sensor head b is placed close to the detection region. Since the light projecting / receiving sensor head b can be installed, the optical path reciprocating between the detected object existing in the detection area and the light projecting / receiving sensor head b can be shortened. be able to. In addition, noise due to disturbance can be suppressed to a small level, and the S / N ratio of the detection light can be increased, thereby improving the detection accuracy of the presence or absence of the detection object in the detection region. However, since the conventional sensor head b with integrated light emitting and receiving and the heat-resistant optical fibers d and f are provided with heat resistance by covering their surfaces with metal or heat-resistant resin, Inside an apparatus for heating glass substrates and wafers in the liquid crystal / semiconductor industry where the furnace is required to be clean without contamination caused by metal ions or heat-resistant resin dust, such as an annealing furnace for glass substrates Has a problem that it cannot be adopted.

  Furthermore, in the conventionally proposed light-and-light integrated sensor head b having heat resistance, the high-temperature resistance may be insufficient in a high-temperature environment of 600 to 700 ° C. such as the above-described annealing furnace.

  Therefore, the present invention can suppress the decrease in the amount of light when detecting the presence or absence of the detection target in the detection region where the cleanliness is required and in a high temperature environment and detecting the behavior using the light as a medium, and the detection accuracy. It is an object of the present invention to provide a sensing method and apparatus using an optical sensor that can be improved.

  In order to solve the above-mentioned problems, the present invention corresponds to the invention according to claim 1 and the invention according to claim 8, and the external environment side from the boundary between the clean and / or high temperature internal environment and the external environment. The light output from the light projecting portion of the photosensor provided at the required location is projected to the required detection area set in the internal environment, and the reflected light is reflected at the detection area. When light is received by the light receiving unit of the optical sensor, one or both of the projected light and the reflected light are detected in the vicinity of the boundary and the detection region in the internal environment or the detection region. A sensing method using an optical sensor that detects the presence and behavior of a detected object in the detection region based on a change in the amount of light received by the light receiving unit of the optical sensor, guided through an optical waveguide member to and from a nearby position And a device.

  Corresponding to the invention according to claim 2 and the invention according to claim 9, a light projecting portion provided at a required location on the external environment side of the boundary between the clean and / or high temperature internal environment and the external environment; The light output from the light projecting unit of the optical sensor having the light receiving unit is projected to a required detection area set in the internal environment, and the light sensor projects the light across the detection area. When the reflected light of the projected light reflected by the reflecting plate provided on the opposite side of the light receiving portion and the light receiving portion is received by the light receiving portion of the photosensor, the projected light and the reflected light One or both of them is guided through an optical waveguide member between a position in the vicinity of the boundary portion and a detection region in the internal environment or a position in the vicinity of the detection region, and is received by the light receiving portion of the optical sensor. Based on the change in the amount of light, detect the presence or absence of the detection object in the detection area And sensing method and apparatus according to the optical sensor.

  Further, in response to the invention according to claim 3 and the invention according to claim 10, the projection of the optical sensor provided at a required location on the external environment side rather than the boundary between the clean and / or high temperature internal environment and the external environment. The light output from the light section is projected to a required detection area set in the internal environment, and the light passing through the detection area is sent to the light receiving section of the photosensor provided on the external environment side. One or both of the projected light and the light received through the detection area when the light is received, the position near the boundary and the detection area or the position near the detection area in the internal environment And a sensing method and apparatus using an optical sensor that detects the presence or absence of a detection object in the detection region based on a change in the amount of light received by the light receiving unit of the optical sensor. .

  As the optical sensor in each configuration described above, an optical fiber sensor in which one or both of the light projecting unit and the light receiving unit are arranged to face the end portion on the external environment side of the optical waveguide member is used.

  Further, the optical waveguide member in each of the above configurations is disposed below the detection region, and the detection object disposed in the detection region can be placed and supported on the upper side of the optical waveguide member. To do.

  Furthermore, the optical waveguide member in each of the above configurations is made of a material having a high transmittance with respect to light projected from the light projecting portion of the optical sensor, a material having a high temperature resistance, or a material having a low dust generation property. Try to use one.

  Further, as the optical waveguide member in each of the above structures, a quartz glass member is used, or an elongated cylindrical shape or elongated cylindrical shape is used. It is set as the structure which used the strand.

  According to the present invention, the following excellent effects are exhibited.

(1) The light output from the light projecting portion of the photosensor provided at the required location on the external environment side than the boundary between the clean and / or high temperature internal environment and the external environment is set in the internal environment. When light is projected to a predetermined detection area and the reflected light of the projected light in the detection area is received by the light receiving unit of the photosensor, one of the projected light and the reflected light Or both may be guided through an optical waveguide member between a position in the vicinity of the boundary and a detection area in the internal environment or a position in the vicinity of the detection area, or light projection of the optical sensor across the detection area When the reflected light of the projected light reflected by the reflecting plate provided on the opposite side of the light receiving portion and the light receiving portion is received by the light receiving portion of the photosensor, the projected light and the reflected light One or both of the above, the position near the boundary and the internal environment The required detection in which the light is guided through the optical waveguide member between the detection area of the sensor and the position near the detection area, or the light output from the light projecting portion of the optical sensor is set in the internal environment. When the light passing through the detection area and light passing through the detection area is received by the light receiving portion of the optical sensor provided on the external environment side, the light is projected and received through the detection area. One or both of the light beams are guided through an optical waveguide member between a position in the vicinity of the boundary and the detection area in the internal environment or a position in the vicinity of the detection area, and received by the light receiving section of the optical sensor. As a sensing method and apparatus using an optical sensor that detects the presence or absence of a detection object in the detection area based on a change in the amount of light to be detected, the detection in the detection area set in the clean and / or high internal environment is performed. The presence or absence of Detai can be detected without influencing the internal environment of the above-described cleaning and or high temperature.
(2) In addition, one or both of a light path until the light projected from the light projecting unit of the optical sensor reaches the detection region and a light path reaching the light receiving unit of the photo sensor from the detection region are guided. Since the loss of light can be suppressed by passing the wave member, the range of increase / decrease in the amount of light when the detection target exists in the detection region and when it does not exist can be expanded, and the clean and / or high temperature It is possible to improve the detection accuracy of the presence / absence of the detection object in the detection region set in the environment.
(3) Further, one or both of a light path until the light projected from the light projecting unit of the optical sensor reaches the detection region and a light path reaching the light receiving unit of the photo sensor from the detection region are guided. Since the optical path when light passes through the space can be shortened by passing through the wave member, the influence of disturbance can be suppressed and the S / N ratio of the detected light can be increased. Therefore, the presence / absence of the detection target in the detection region set in the clean and / or high-temperature environment as described above can be accurately detected.
(4) When an optical fiber sensor in which one or both of the light projecting unit and the light receiving unit are arranged so as to face the end portion on the external environment side of the optical waveguide member is used as the optical sensor, the light projecting unit and the light receiving unit are used. The end portion of the optical fiber becomes a close proximity to the end portion of the optical waveguide member on the external environment side, so that the light projecting portion and the light receiving portion of the optical sensor and the external environment side of the optical waveguide member It can be advantageous for efficient propagation of light between the end portions.
(5) By arranging the optical waveguide member on the lower side of the detection region and placing the object to be detected arranged on the detection region on the upper side of the optical waveguide member so as to be supported. The optical waveguide member can be used as a supporting member for supporting the detection target, and by supporting the detection target in this way, the optical waveguide member and the detection target are brought into contact with each other. Therefore, it is possible to further shorten the optical path when light projected and received from the optical sensor passes through the space.
(6) By using a light waveguide member made of a material having a high transmittance for the light projected from the light projecting portion of the optical sensor, the light is projected from the light projecting portion of the optical sensor. One or both of the light path until the light reaches the detection area and the light path from the detection area to the light receiving portion of the optical sensor is advantageous for suppressing light loss when passing through the optical waveguide member. This can be advantageous for improving the detection accuracy of the presence or absence of the detection target in the detection region.
(7) By using an optical waveguide member made of a material having a high temperature resistance and a material having a low dusting property, the internal environment where the detection region is set is a high temperature environment, or a metal The present invention can be easily applied to a clean environment in which contamination and dust generation should be prevented, or a high temperature environment and a clean environment.
(8) By using an optical waveguide member made of quartz glass, it has a high transmittance for light output from the light projecting portion of the optical sensor, high temperature resistance, and properties that do not generate dust. An optical waveguide member can be easily obtained.
(9) By making the optical waveguide member into an elongated columnar shape or an elongated cylindrical shape, the light propagation direction in the optical waveguide member can be narrowed down to the axial direction. Further, when the elongated cylindrical shape is used, total reflection using the cylindrical wall surface can be easily generated. On the other hand, when an elongated cylindrical shape is used, it is possible to easily cause light reflection using the inner wall surface. Therefore, regardless of whether the optical waveguide member has an elongated columnar shape or a cylindrical shape, it can be advantageous to suppress loss of light propagated in the optical waveguide member.
(10) By adopting a configuration in which an optical fiber strand that is exposed by peeling off the coating of the optical fiber is used as the optical waveguide member, there is no need to separately provide an optical waveguide member. It is possible to make it advantageous for reduction.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows an embodiment of a sensing method and apparatus using an optical sensor according to the present invention, which is applied to an optical sensor that performs sensing using a reflective optical fiber sensor having a light projecting unit and a light receiving unit as separate units. Indicates when to do.

  For example, a ceiling constituting a quartz box (quartz chamber) 1 in an annealing furnace for a glass substrate with a silicon film in the manufacturing process of a liquid crystal panel is used as a boundary between the clean environment and the high temperature environment. An opening 2 having a required diameter penetrating inward and outward is provided at a required portion of one of the walls, side walls, and floor, for example, one side wall 1a, and an optical waveguide member is provided at the tip of the opening 2 inside the furnace. (One end) is in the vicinity of the required detection region 4 where the detection target 5 such as the glass substrate with silicon film is to be detected, or when the detection target 5 is disposed in the detection region 4 Arrangement is made so as to reach the position where it comes into contact with the surface of the detection object 5 and the base end portion (the other end portion) is positioned so as to be exposed to the outside by being located in the opening portion 2, and will be described later. So as to be held by the member 6 To. Here, the optical waveguide member is a member made of a single material capable of propagating light with high transmittance, or a core portion that propagates light with high transmittance, and the core portion provided on the outer periphery of the core portion. As a double-structured member consisting of a clad portion made of a material having a lower refractive index, or as a hollow cylinder, the inner wall surface functions as a light reflecting surface, so that it enters the inner space from one end. It refers to a member that can guide light through the internal space to the other end with a low loss. In this embodiment, for example, the columnar quartz glass member 3 is made of a single quartz glass.

  The optical waveguide member is made of quartz glass member 3, that is, made of quartz glass, because quartz glass is a material having a high transmittance with respect to light output from a light projecting portion of an optical fiber sensor 8 to be described later. At the same time, it is a material having high temperature resistance, and furthermore, it is a material having no risk of metal contamination and low dust generation. In the present specification, the high transmittance means a transmittance that can be generally regarded as transparent with respect to the light used in the optical fiber sensor 8, or a degree required for a member that is usually used as a transmission optical material. It means the transmittance. The high temperature resistance means a characteristic that can be used in a high temperature environment of 250 ° C. or higher, preferably 700 ° C. or higher. Furthermore, a material having low dust generation generally means a low dust generation material as required for a member used in a clean room.

  Further, a window 7 of a required size including a window glass 7a is provided at a required position near the opening 2 provided on one side wall 1a of the quartz box 1 as shown in FIG. Like the quartz glass member 3, the window glass 7a has a high transmittance with respect to light output from the light projecting portion of the optical fiber sensor 8, has high temperature resistance, and has no risk of metal contamination. For example, it is made of quartz glass.

  Further, a required portion outside the quartz box 1 is individually provided on a sensor body (not shown) having a light source and a photodetector, and on the output side of the light source and the input side of the photodetector in the sensor body. A reflection type optical fiber sensor 8 is provided as an optical sensor composed of a light projecting optical fiber 9 and a light receiving optical fiber 11 to which ends are connected. The tip of the light projecting optical fiber 9 of the reflective optical fiber sensor 8 is held by the coupling member 6 at the position of the opening 2 of the quartz box side wall 1a, and the tip of the light projecting optical fiber 9 is retained. Is connected optically to the base end portion which is the end portion on the external environment side of the quartz glass member 3, and the distal end portion of the projecting optical fiber 10 as the projecting portion of the projecting optical fiber 9 So that light can be propagated to the base end of the quartz glass member 3. On the other hand, the light receiving optical fiber 11 of the reflection type optical fiber sensor 8 has its tip positioned near the outside of the window 7 provided on the quartz box side wall 1a, and as a light receiving portion of the light receiving optical fiber 11. The light receiving optical fiber 12 is arranged so that the front end (tip surface) of the light receiving optical fiber 12 faces the detection region 4 inside the quartz box 1 through the window 7 and is supported and fixed by a support mechanism (not shown). As a result, the light 13 guided from the sensor body through the projecting optical fiber 10 of the projecting optical fiber 9 is guided to the position near the detection region 4 in the quartz box 1 through the quartz glass member 3. Then, light can be projected toward the detection area 4. At the time of this light projection, if the detected object 5 exists in the detection region 4, the projected light 13 is specularly reflected or scattered and reflected by the detected object 5, so that the reflected light 13a is Light can be received through the window 7 on the side wall 1a of the quartz box to the front end surface of the light receiving optical fiber 12 of the light receiving optical fiber 11.

  Specifically, first, the opening 2 of the side wall 1 a of the quartz box 1 has the same outer diameter as the inner diameter of the opening 2 and the inner diameter is the same as the outer diameter of the light projecting optical fiber 9. Insert a coupling member 6 made of a heat-resistant material that does not cause metal contamination or dust generation, such as ceramic or glass formed into a pipe shape of a required length, and both axial ends of the coupling member 6 are inside and outside the furnace Each of the connecting members 6 is disposed so as to protrude in the direction by a required dimension, and the required portion of the outer peripheral surface of the coupling member 6 is fixed to the opening 2.

  Next, on the inner side of the protruding portion of the coupling member 6 toward the furnace inside, a flat cylindrical shape having an outer diameter similar to that of the projecting optical fiber 9 and both end faces are perpendicular to the axial direction. Then, the base end portion of the quartz glass member 3 polished so as to be inserted is inserted to hold the quartz glass member 3. Further, the projecting portion of the coupling member 6 to the outside of the furnace exposes the tip of the light projecting optical fiber 9 and the light projecting optical fiber 10 is exposed at the tip. The optical fiber strand 10 is inserted in a polished state so that the front end surface of the optical fiber strand 10 is a plane perpendicular to the axial direction, and the front end portion of the light projecting optical fiber 9 is held by the coupling member 6, Inside the intermediate portion of the member 6, the distal end surface of the optical fiber strand 10 of the light projecting optical fiber 9 and the proximal end surface serving as the end portion on the external environment side of the quartz glass member 3 are in surface contact. To do. The distal end portion of the light projecting optical fiber 7 and the proximal end portion of the quartz glass member 3 are fixed inside the coupling member 6. In FIG. 1, 9 a is a coating on the light projecting optical fiber 9, and 11 a is a coating on the light receiving optical fiber 11.

  The quartz glass member 3 has an elongated cylindrical shape because the direction in which the light 13 incident from the light projecting optical fiber 10 of the light projecting optical fiber 9 passes through the quartz glass member 3 is the cylinder axis direction. Accordingly, total reflection based on the difference in refractive index between the quartz glass member 3 and the atmospheric gas in the quartz box 1 is easily caused on the cylindrical side surface of the quartz glass member 3, so that the quartz glass member 3 is This is because the light 13 incident from the projecting optical fiber 10 to the base end face can be propagated to the front end face in a state where the loss inside the quartz glass member 3 is suppressed. Therefore, it is preferable to make the diameter of the quartz glass member 3 as thin as possible within a range where necessary strength can be obtained, for example, the shape can be maintained.

  With the above configuration, the presence or absence of the detected object 5 is detected using the sensing device of the present invention in the required detection region 4 set in the quartz box 1 of the annealing furnace that is clean and in a high temperature environment. When detecting, the light 13 guided from the light source of the main body of the reflection type optical fiber sensor 8 through the light projecting optical fiber 10 of the light projecting optical fiber 9 is transmitted to the light projecting optical fiber 10. Output (project light) from the tip surface (projection surface). Next, after the light 13 projected from the distal end surface of the light projecting optical fiber 10 is incident on the quartz glass member 3 from the base end surface side, the inside of the quartz glass member 3 having high transmittance is passed through. Then, after guiding to the position of the tip surface of the quartz glass member 3, that is, in the vicinity of the detection region 4 in a state where light loss is suppressed using total reflection, the detection region 4 is detected from the tip surface of the quartz glass member 3. So that the light is emitted toward

  When the detection object 5 is not present in the detection region 4, the light 13 projected from the tip surface of the quartz glass member 3 to the detection region 4 is dissipated in the detection region 4. Reflected light hardly occurs. Therefore, the light is received by the front end surface (light receiving surface) of the light receiving optical fiber 12 of the light receiving optical fiber 11 of the reflective optical fiber sensor 8 disposed outside the window 7 provided on the quartz box side wall 1a. Since the light to be transmitted is limited to the background light reaching the light receiving surface of the light receiving optical fiber 12, it is detected by the photodetector of the sensor body through the light receiving optical fiber 12. The amount of received light is small.

  On the other hand, as shown by a two-dot chain line in FIG. 1, when the detection object 5 exists in the detection region 4, the light projected from the tip surface of the quartz glass member 3 toward the detection region 4. 13 is specularly reflected or scattered and reflected by the detected object 5 existing in the detection region 4, and is reflected on the quartz box side wall 1 a out of the reflected light 13 a generated by the specular reflection, scattering reflection, or both regular reflection and scattering reflection. The reflected light 13a that has passed through the provided window 7 (transmitted through the window glass 7a) is disposed at a position near the outside of the window 7, and the light receiving surface of the light receiving optical fiber 12 of the light receiving optical fiber 11 is provided. To receive light. Also in this case, since the background light is incident on the light receiving surface of the light receiving optical fiber 12, the amount of light received by the light receiving optical fiber 12 is the detection region 4. Compared to the case where the detected object 5 does not exist, the reflected light 13a from the detected object 5 reaching the light receiving surface of the light receiving optical fiber 12 is added.

  Therefore, based on whether or not the amount of light received by the photodetector of the sensor body through the light receiving optical fiber 12 is increased from the initial state, the detection region 4 in the quartz box 1 is set in the detection region 4. Whether or not the detected object 5 is present can be detected in the same manner as the conventional reflective optical fiber sensor.

  Thus, in the present invention, only the quartz glass member 3, the quartz glass window glass 7a, and the coupling member 6 made of a heat-resistant material that does not cause metal contamination and dust generation are contained in the quartz box 1. Since only is exposed, it is possible to prevent the risk of metal contamination and heat-resistant resin dusting from the sensor head and the heat-resistant coating of the optical fiber in the conventional optical fiber sensor. Therefore, it is possible to detect the presence or absence of the detection target 5 in the detection region 4 set in the quartz box 1 of the annealing furnace that is clean and has a high temperature environment without affecting the clean and high temperature environment. it can.

  Moreover, since the quartz glass member 3 and the window glass 7a made of quartz glass have excellent high temperature resistance, the high temperature conditions such as in the quartz box 1 of the annealing furnace in which the furnace is 600 to 700 ° C., Further, it is possible to detect the presence or absence of the detection object 5 even in the detection region 4 under further high temperature conditions up to the vicinity of the softening point of quartz glass.

  In the quartz glass member 3, the light 13 incident from the base end surface can be transmitted to the distal end surface in a state where the loss of light is suppressed by using the high light transmittance of the quartz glass member 3 and total reflection. Therefore, the light 13 output from the light projecting optical fiber 10 of the light projecting optical fiber 9 in the reflective optical fiber sensor 8 is efficiently guided to the vicinity of the detection region 4, and the quartz glass member The light can be projected toward the detection region 4 from the tip surface of 3.

  For this reason, it is possible to prevent a decrease in the amount of light before reaching the detection region 4 from the tip of the light projecting optical fiber 9 as the light projecting portion of the reflective optical fiber sensor 8. As a result, the light 13 projected from the tip of the light projecting optical fiber 9 as the light projecting section of the reflection type optical fiber sensor 8 is reflected by the detected object 5 existing in the detection region 4, and this reflection The light passing through the window 7 provided in the quartz box side wall 1a on the light path when the light 13a is received by the tip of the light receiving optical fiber 11 as the light receiving portion of the reflection type optical fiber sensor 8. Can be only reflected light 13a by the detection object 5 in the detection region 4. Therefore, even if the reflected light 13a from the detected object 5 is scattered when passing through the window 7, both the light projecting part and the light receiving part of the reflection type optical sensor or optical fiber sensor are outside the window. As in the case where the light is projected and received through the window, both the light to be projected and the reflected light of the detection target to be received are transmitted through the window, so that the reduction in the amount of light due to light scattering in the window is synergistic. Compared with the case where it was done, the fall of the light quantity detected with a photodetector can be suppressed. Therefore, the range of increase / decrease in the amount of light when the detected object 5 exists in the detection region 4 and when it does not exist can be expanded.

  Further, the light 13 projected from the tip of the light projecting optical fiber 9 as the light projecting section of the reflection type optical fiber sensor 8 is reflected by the detected object 5 existing in the detection region 4, and this reflected light. A space between the detection region 4 and the window 7 is formed on the light path when the light 13a is received by the tip of the light receiving optical fiber 11 serving as the light receiving portion of the reflective optical fiber sensor 8. The light passing therethrough can be only the reflected light 13a by the detected object 5 in the detection region 4. Therefore, even if the reflected light 13a from the detected object 5 passes through the space from the detection region 4 to the window 7, even if noise is mixed under the influence of disturbance, the reflected light 13a is reflected. When the light projecting part and the light receiving part of the optical sensor and the optical fiber sensor are both provided outside the window and light is projected and received through the window, that is, they are mixed in the forward and backward paths of light from the window to the detection area, respectively. The mixed noise can be reduced as compared with the case where the amount of noise is synergistic. Thereby, the S / N ratio of the detection light in the reflective optical fiber sensor 8 can be increased. Therefore, the presence / absence of the detection object 5 in the detection region 4 in a clean environment such as the inside of the quartz box 1 and in a high temperature environment can be accurately detected.

  Next, as in the embodiment shown in FIG. 1, FIG. 2 shows another case in which sensing is performed by a reflection type optical fiber sensor in which a light projecting unit and a light receiving unit are separated as an optical sensor. For example, in the same configuration as shown in FIG. 1, the tip of the projecting optical fiber 9 as the projecting unit of the reflective optical fiber sensor 8 is connected to the furnace of the side wall 1 a of the quartz box 1 of the annealing furnace. It is optically connected to the base end of the quartz glass member 3 that is arranged so that the front end protrudes to the vicinity of the required detection region 4 on the inside, while the light receiving portion of the reflective optical fiber sensor 8 The tip of the light receiving optical fiber 11 is arranged in the vicinity of the outside of the window 7 provided on the quartz box side wall 1a so as to face the detection region 4 inside the quartz box 1 through the window 7. Instead, reflective optical fiber A required detection region inside the quartz box 1 is passed through the window 7 at a position near the outside of the window 7 provided on the side wall 1a of the quartz box 1 at the tip end of the light projecting optical fiber 9 as the light projecting part of the sensor 8. 4, while the front end of the light receiving optical fiber 11 serving as the light receiving portion of the reflective optical fiber sensor 8 is located on the inner side of the side wall 1 a of the quartz box 1 of the annealing furnace, the front end is the above. The quartz glass member 3 is disposed so as to protrude to the vicinity of the detection region 4 and is optically connected to the base end portion of the quartz glass member 3.

  Specifically, as in the embodiment of FIG. 1, an opening 2 is provided in the side wall 1 a of the quartz box 1, and the base end of the quartz glass member 3 is connected to the opening 2 in a pipe-like connection. A window 7 having a window glass 7a made of quartz glass is provided at a required position in the vicinity of the opening 2 in the quartz box side wall 1a while being attached via the member 6.

  Further, in the same manner as the optical connection method between the base end portion of the quartz glass member 3 and the tip end portion of the light projecting optical fiber 9 of the reflection type optical fiber sensor 8 in the embodiment of FIG. 6 is inserted and attached to the protruding portion outside the furnace 6 of the reflection type optical fiber sensor 8, and the light receiving portion of the light receiving optical fiber 11 is inserted from the base end portion of the quartz glass member 3. The light can be propagated to the tip of the optical fiber 12 for receiving light. Further, the tip end portion of the light projecting optical fiber 9 as the light projecting portion of the reflection type optical fiber sensor 8 is disposed at a position near the outside of the window 7 of the quartz box side wall 1a, and the quartz box side wall in the embodiment of FIG. The light receiving optical fiber 11 is disposed in the same manner as the light receiving optical fiber 11 near the outside of the window 1a. Other configurations are the same as those shown in FIG. 1, and the same components are denoted by the same reference numerals.

  When detecting the presence or absence of the detected object 5 in the required detection region 4 set in the quartz box 1 using the sensing device of the present embodiment, the sensor body of the reflective optical fiber sensor 8 is detected. The light 13 guided from the light source through the light projecting optical fiber 10 of the light projecting optical fiber 9 is output from the front end surface (light projecting surface) of the light projecting optical fiber 10 as the light projecting portion ( The output light 13 is projected onto the detection region 4 through the window 7. In this state, when the detection target 5 does not exist in the detection region 4, the light 13 projected to the detection region 4 through the window 7 from the tip surface of the light projecting optical fiber 10 is Since it is dissipated in the detection region 4, it does not enter the tip surface of the quartz glass member 3 disposed in the vicinity of the detection region 4. Therefore, the front end surface (light receiving surface) of the light receiving optical fiber 12 of the light receiving optical fiber 11 as the light receiving portion of the reflective optical fiber sensor 8 optically connected to the base end surface of the quartz glass member 3. Since the light received at is limited to background light, the amount of received light detected by the photodetector of the sensor body via the light receiving optical fiber 12 is small.

  On the other hand, as shown by a two-dot chain line in FIG. 2, when the detected object 5 is present in the detection region 4, The light 13 projected through the window 7 toward the detection area 4 is specularly reflected or scattered and reflected by the detected object 5 existing in the detection area 4, and the regular reflection or scattered reflection or regular reflection and scattering reflection. The reflected light 13 a generated by both of the light enters the front end surface of the quartz glass member 3 disposed in the vicinity of the detection region 4. The reflected light 13a incident on the quartz glass member 3 from its front end surface is transmitted through the quartz glass member 3 having a high transmittance, and the base end of the quartz glass member 3 in a state where light loss is suppressed using total reflection. And is received from the proximal end surface of the quartz glass member 3 to the distal end surface (light receiving surface) of the light receiving optical fiber 12 of the light receiving optical fiber 11. Also in this case, since the background light is incident on the light receiving surface of the light receiving optical fiber 12, the amount of light received by the light receiving optical fiber 12 is the detection region 4. Compared to the case where the detected object 5 does not exist, the reflected light 13a from the detected object 5 reaching the light receiving surface of the light receiving optical fiber 12 is added.

  Therefore, as in the embodiment of FIG. 1, the amount of received light detected by the photodetector of the sensor body via the light receiving optical fiber 12 is based on whether or not the amount of light received is increased from the initial state. It becomes possible to detect whether or not the detection object 5 is present in the detection region 4 in the quartz box 1.

  Further, in the quartz glass member 3, the reflected light 13 of the detection target 5 incident from the front end surface is in a state in which light loss is suppressed by utilizing the high light transmittance of the quartz glass member 3 and total reflection. Since the light can be transmitted to the base end face, the reflected light 13a from the detection object 5 when the detection object 5 is present in the detection region 4 is transmitted from the vicinity of the detection region 4 to the quartz box side wall 1a. Thus, the light receiving optical fiber 12 of the light receiving optical fiber 11 in the reflection type optical fiber sensor 8 can receive light. For this reason, it is possible to prevent a decrease in the amount of light from the detection region 4 until reaching the tip of the light receiving optical fiber 11 as the light receiving portion of the reflective optical fiber sensor 8.

  As a result, the light 13 projected from the tip of the light projecting optical fiber 9 as the light projecting section of the reflection type optical fiber sensor 8 is reflected by the detected object 5 existing in the detection region 4, and this reflection On the light path when the light 13a is received by the tip of the light receiving optical fiber 11 as the light receiving portion of the reflection type optical fiber sensor 8, the window 7 provided on the quartz box side wall 1a and the window The light passing through the space between 7 and the detection region 4 can be only the light 13 projected from the light projecting optical fiber 9.

  Therefore, also in the present embodiment, a decrease in the amount of light detected by the photodetector in the reflection type optical fiber sensor 8 can be suppressed, and when the detected object 5 exists in the detection region 4 The range of increase / decrease in the amount of light when it does not exist can be expanded. Further, the S / N ratio of the detection light in the reflection type optical fiber sensor 8 can be increased, and the detection object 5 in the detection region 4 in a clean environment and a high temperature environment such as in the quartz box 1 can be obtained. The same effect as the embodiment of FIG. 1 can be obtained, such as the presence / absence detection accuracy being improved. Further, in the present embodiment, the quartz glass member 3 is provided on the path on the light receiving side of the reflected light 13a from the detected object 5 and is directly involved in the detection of the presence or absence of the detected object 5 in the detection region 4. Since the light receiving unit of the reflection type optical fiber sensor 8 can receive light while suppressing the loss of the reflected light 13a, the detection sensitivity of the presence or absence of the detection target 5 in the detection region 4 is expected to be improved. it can.

  Next, as in the embodiment shown in FIG. 1, FIG. 3 shows still another case in which sensing is performed using a reflection type optical fiber sensor in which a light projecting unit and a light receiving unit are separated as an optical sensor. For example, in the same configuration as shown in FIG. 1, the tip end of a light projecting optical fiber 9 as a light projecting portion of the reflective optical fiber sensor 8 and the tip of a light receiving optical fiber 11 as a light receiving portion are shown. Only the tip of the light projecting optical fiber 9 is arranged so that the tip protrudes to the vicinity of the required detection region 4 inside the side wall 1a of the quartz box 1 of the annealing furnace. Instead of the optically connected configuration to the base end portion of the quartz glass member 3, the distal end portion of the light projecting optical fiber 9 as the light projecting portion of the reflective optical fiber sensor 8 and the light receiving portion as the light receiving portion. Both ends of the optical fiber 11 , And optically connected to the base ends of the individual quartz glass members 3 that are arranged so that the front ends protrude to the vicinity of the required detection region 4 on the inside of the quartz box side wall 1a of the annealing furnace. It is what you do.

  More specifically, the one shown in FIG. 3 is provided with two adjacent openings 2 at a required position of the quartz box side wall 1a, and each of the openings 2 has the quartz glass member 3 shown in FIG. The base ends of the quartz glass members 3a and 3b similar to the above are individually attached via the coupling members 6a and 6b. Furthermore, the distal end portion of the light projecting optical fiber 9 as the light projecting portion of the reflective optical fiber sensor 8 is disposed at the base end portion of one quartz glass member 3a, and the distal end portion of the light receiving optical fiber 11 is disposed. The other quartz glass member 3b is optically connected to the base end portion thereof.

  The method for attaching the light emitting side and light receiving side quartz glass members 3a and 3b via the coupling member 6 to each opening 2 of the quartz box side wall 1a is shown in the embodiment of FIG. The method of attaching the quartz glass member 3 to the opening 2 is the same. Further, the optical connection method between the proximal end portions of the quartz glass members 3a and 3b and the distal end portions of the light projecting and receiving optical fibers 9 and 11 is the same as that in the embodiment of FIG. This is the same as the optical connection method between the proximal end portion of the quartz glass member 3 and the distal end portion of the light projecting optical fiber 9 of the reflection type optical fiber sensor 8. Other configurations are the same as those shown in FIG. 1, and the same components are denoted by the same reference numerals.

  According to the present embodiment, when detecting the presence or absence of the detection object 5 in the required detection region 4 set in the quartz box 1 which is clean and in a high temperature environment, the reflection type optical fiber sensor The light 13 guided from the light source of the sensor body 8 through the light projecting optical fiber 10 of the light projecting optical fiber 9 is used as the front end surface of the light projecting optical fiber 10 as a light projecting unit (light projecting). When the light is output (projected) from the surface, the light 13 output from the distal end portion of the optical fiber for projection 9 is incident from the base end surface of the quartz glass member 3a on the projecting side, as in FIG. Therefore, in the quartz glass member 3a on the light-projecting side having high light transmittance, the tip surface near the detection region 4 can be efficiently obtained in a state where light loss is suppressed by using total reflection. Guided and projected toward the detection region 4 from the front end surface of the quartz glass member 3a on the projection side It can be.

  The projected light 13 is dissipated when the detection object 5 is not present in the detection region 4. On the other hand, as shown by a two-dot chain line in FIG. 3, when reflected light 13 a is generated by the detected object 5 of the projected light 13 when the detected object 5 exists in the detection region 4, the reflected light 13 a is generated. Is incident on the distal end surface of the quartz glass member 3b on the light receiving side that is optically connected to the distal end portion of the light receiving optical fiber 11 at a position in the vicinity of the detection region. In the quartz glass member 3b on the light receiving side, the light is efficiently guided to the base end surface while suppressing the loss of light using total reflection, and the reflection is performed from the base end surface of the quartz glass member 3 on the light receiving side. The light receiving optical fiber 11 of the light receiving optical fiber 11 serving as the light receiving portion of the optical fiber sensor 8 can receive light on the tip surface of the light receiving optical fiber strand 12, and the received reflected light 13 a is received by the light receiving optical fiber strand 12. Then, the light is guided to the photodetector.

  Therefore, also according to the present embodiment, the presence or absence of the detection object 5 in the detection region 4 in the quartz box 1 is changed by the change in the amount of received light detected by the photodetector of the sensor body through the light receiving optical fiber 12. Can be detected based on Moreover, in the present embodiment, the light 13 projected from the tip of the light projecting optical fiber 9 as the light projecting section of the reflective optical fiber sensor 8 is detected by the detected object 5 present in the detection region 4. The reflected light 13a is reflected on the light path when the reflected light 13a is received by the distal end portion of the light receiving optical fiber 11 as the light receiving portion of the reflection type optical fiber sensor 8, and the projected light 13 and None of the reflected light 13a from the detection object 5 passes through the window and does not pass through the space between the detection region 4 and the window. For this reason, from the front-end | tip part of the optical fiber 9 for light projection as a light projection part of the said reflection type optical fiber sensor 8 to the to-be-detected body 5, and the light-receiving part of the said reflection type optical fiber sensor 8 from this to-be-detected body 5 When the detection target 5 is present in the detection region 4 and when the detection target 5 is not present, it is possible to further suppress a decrease in the amount of light when the light 13, 13a travels to the tip of the light receiving optical fiber 11 as The range of increase / decrease in the amount of light can be further expanded. Further, the S / N ratio of the detection light in the optical fiber sensor 8 can be further increased, and the presence or absence of the detection object 5 in the detection region 4 in a clean environment and a high temperature environment such as in the quartz box 1. The detection accuracy can be further improved.

  4 (a) and 4 (b) show a modification of the embodiment shown in FIG. 3. In the same configuration as shown in FIG. 3, the tip of the light projecting optical fiber 9 of the reflective optical fiber sensor 8 is shown. Instead of the structure in which the optical fiber 11 and the distal end of the light receiving optical fiber 11 are optically connected to the base ends of the corresponding quartz glass members 3a and 3b, respectively, the side wall of the quartz box 1 of the annealing furnace Inside the furnace of 1a, the tip reaches a position near the required detection area 4 or a position where the detection object 5 comes into contact with the surface of the detection object 5 when the detection object 5 is arranged in the detection area 4. The other end portion of the quartz glass member 3c serving as one optical waveguide member shared for light projection and reception disposed in this manner is connected to the tip portion of the light projecting optical fiber 9 as the light projecting portion of the reflective optical fiber sensor 8. A tip of the light receiving optical fiber 11 as a light receiving portion; It is obtained so as to optically connect together.

  More specifically, the one shown in FIGS. 4 (a) and 4 (b) is a little more than the sum of the outer diameters of the light projecting optical fiber 9 and the light receiving optical fiber 11 on one side wall 1a of the quartz box 1. An opening 2 having a large inner diameter is provided. Furthermore, the outer diameter is made the same size as the inner diameter of the opening 2 and made of one end side, made of a heat-resistant material that does not cause metal contamination and dust generation such as ceramic and glass similar to the coupling member 6 shown in FIG. An optical waveguide member mounting recess 16 is formed in the opening 2 so that the coupling member 14 having a required length having the fiber mounting holes 15a and 15b penetrating on the other end is disposed on the recess 16 side. Inserting and arranging the both ends of the coupling member 14 in the axial center direction so as to project each required dimension in the inside and outside of the furnace, and fixing the required portion of the outer peripheral surface of the coupling member 14 to the opening 2 Like that.

  The two fiber mounting holes 15a and 15b opened to the outside of the coupling member 14 are substantially the same as the diameters of the light projecting optical fiber 9 and the light receiving optical fiber 11 as shown in FIG. And adjacent to each other so as to reach a position substantially corresponding to the quartz box side wall 1a. On the other hand, the recess 16 formed in the end surface inside the furnace of the coupling member 14 is used when the light projecting optical fiber 9 and the light receiving optical fiber 11 are inserted into the fiber mounting holes 15a and 15b, respectively. The inner diameter of the optical fiber 9 is larger than the radial position where the light-receiving optical fiber 12 and the light-receiving optical fiber 12 of the light-receiving optical fiber 11 are arranged. The fiber mounting holes 15a and 15b It is provided to communicate.

  The quartz glass member 3c used for both light projection and reception has an elongated cylindrical shape having an outer diameter corresponding to the inner diameter of the optical waveguide member mounting recess 16 of the coupling member 14, and both end surfaces are planes perpendicular to the axial direction. Grind so that it becomes.

  Next, the base end portion of the quartz glass member 3c is inserted into the optical waveguide member mounting recess 16 of the coupling member 14 and fixed. Further, inside the fiber mounting holes 15a and 15b outside the furnace in the coupling member 14, the tip of the light projecting optical fiber 9 and the tip of the light receiving optical fiber 11 of the reflection type optical fiber sensor 8 are provided. The light projecting optical fiber 10 and the light receiving optical fiber 12 are exposed at the tips, respectively, and the exposed tip surfaces of the exposed optical fiber strands 10 and 12 are in a plane perpendicular to the axial direction. Inserted in a polished state, fixed respectively, and inside the intermediate portion of the coupling member 14, the tip surfaces of the light projecting and receiving optical fiber strands 10 and 12, and the quartz glass member The base end face of 3c is brought into surface contact. Thereby, from the front-end | tip part of the optical fiber 10 for light projection as a light projection part of the said optical fiber 9 for light projection to the base end part of the said quartz glass member 3c, and the base end part of this quartz glass member 3c The light can be propagated from the light receiving optical fiber 11 to the tip of the light receiving optical fiber 12 as the light receiving portion of the light receiving optical fiber 11.

  Other configurations are the same as those shown in FIG. 3, and the same components are denoted by the same reference numerals.

  According to the present embodiment, when detecting the presence or absence of the detected object 5 in the required detection region 4 set in the quartz box 1 which is clean and in a high temperature environment, the reflection type optical fiber sensor The light 13 guided from the light source of the sensor main body 8 through the light projecting optical fiber 10 of the light projecting optical fiber 9 is used as a light emitting portion. When the light is output (projected) from the surface), the light 13 output from the distal end portion of the optical fiber 9 for projecting light is incident from the base end surface of the quartz glass member 3c, and within the quartz glass member 3c, In a state where light loss is suppressed, the light can be efficiently guided to the front end surface in the vicinity of the detection region 4, and can be projected toward the detection region 4 from the front end surface of the quartz glass member 3 a on the light projection side. Further, as shown by a two-dot chain line in FIG. 4, the reflected light 13a of the projected light 13 generated by the detected object 5 when the detected object 5 is present in the detected area 4 is located in the vicinity of the detected area. The reflected light 13a is efficiently guided to the base end surface while suppressing loss of light in the quartz glass member 3c. Light can be received from the base end face to the front end face of the light receiving optical fiber 12 of the light receiving optical fiber 11 as the light receiving portion of the reflection type optical fiber sensor 8.

  In this embodiment, since the quartz glass member 3c is used for both light projection and reception, light is received at the front end surface of the light receiving optical fiber 12 when the detection object 5 is not present in the detection region 4. Internally reflected light generated by the reflected light 13 being internally reflected by the tip surface of the quartz glass member 3c or the like is added to the background light. However, the internally reflected light in the quartz glass member 3c is limited to a light amount smaller than the reflected light 13a generated by the presence of the detected object 5 in the detection region 4. Therefore, the case where the light received by the front end surface of the light receiving optical fiber 12 is only the background light when the detection target 5 is not present in the detection region 4 and the background light is detected. A change in the amount of light received when the reflected light 13a generated by the presence of the detected object 5 in the region 4 is added may be caused by a change that can be sufficiently detected by the photodetector of the sensor body. it can.

  Therefore, also in the present embodiment, as in the embodiment shown in FIG. 3, the presence or absence of the detection object 5 in the detection region 4 in the quartz box 1 in a clean environment and in a high temperature environment is determined based on the light for receiving light. Detection is possible based on a change in the amount of received light detected by the photodetector of the sensor body through the fiber strand 12. Further, the light 13 projected from the tip of the light projecting optical fiber 9 as the light projecting section of the reflection type optical fiber sensor 8 is reflected by the detected object 5 existing in the detection region 4, and this reflected light. The light path when the light 13a is received by the tip of the light receiving optical fiber 11 serving as the light receiving portion of the reflection type optical fiber sensor 8 passes through the quartz glass member 3c for both light projection and light reception. Therefore, neither the projected light 13 nor the reflected light 13a from the detected object 5 passes through the window, and does not pass through the space between the detection region 4 and the window. The same effects as those of the embodiment shown in FIG. Furthermore, in this embodiment, since only one quartz glass member 3c for both light and light reception is provided, the number of members can be reduced as compared with the embodiment shown in FIG. Can be expected.

  FIG. 5 shows another embodiment of the present invention, which is applied to an optical sensor that performs optical sensing using a reflection type optical fiber sensor in which a light projecting / receiving unit is integrated. As a configuration.

  That is, in the same configuration as shown in FIG. 4, a reflection type optical fiber sensor 8 provided at a required location outside the quartz box 1 includes a sensor body (not shown), a light source output side and a light detector input side of the sensor body. Instead of a configuration comprising a light projecting optical fiber 9 and a light receiving optical fiber 11 each having a base end connected individually to the optical fiber, a reflection type optical fiber sensor 8 includes a sensor body (not shown), The light projecting optical fiber 10 and the light receiving optical fiber 12, each having a proximal end connected to the light source output side and the light detector input side of the sensor body, are combined into a single cable. The tip of the projecting optical fiber 10 serving as the light projecting portion of the reflective optical fiber sensor 8 is configured as a light projecting / receiving optical fiber, for example, a parallel optical fiber 17. , The tip portion of the light receiving optical fiber 12 serving as the light receiving unit is set to be an integral at the distal end portion of one of the parallel optical fiber 17. Furthermore, the tip of the parallel optical fiber 17 is arranged so that the tip protrudes to the vicinity of the required detection region 4 inside the side wall 1a of the quartz box 1 of the annealing furnace, as shown in FIG. It is optically connected to the base end portion of the quartz glass member 3c used for both light projection and reception.

  Specifically, an opening 2 is provided at a required portion of the quartz box side wall 1 a, the outer diameter of the opening 2 is the same as the inner diameter of the opening 2, and the inner diameter is the same as that of the parallel optical fiber 17. Insert a coupling member 6 made of a heat-resistant material that does not cause metal contamination or dust generation, such as ceramic or glass, having the same dimension as the outer diameter and formed into a pipe shape of a required length, and the shaft center of the coupling member 6 Both end portions in the direction are arranged so as to project each required dimension in the inside / outside direction of the furnace, and further, a required portion of the outer peripheral surface of the coupling member 6 is fixed to the opening 2.

  Next, inside the protruding portion of the coupling member 6 toward the furnace inside, an elongated cylindrical shape having the same outer diameter as that of the parallel optical fiber 17 is formed so that both end faces are planes perpendicular to the axial direction. The base end portion of the polished quartz glass member 3c that is polished for light transmission and reception is inserted to hold the quartz glass member 3c. The tip of the parallel optical fiber 17 is inserted into the protruding portion of the coupling member 6 to the outside of the furnace. At this time, the optical fiber strands 10 and 12 for projecting and receiving light are connected. Both ends are exposed at the tip, and the exposed tip surfaces of the optical fiber strands 10 and 12 are inserted in a polished state so as to be a plane perpendicular to the axial direction, and the tip portion of the parallel optical fiber 17 is inserted. The coupling member 6 is held. Further, inside the intermediate portion of the coupling member 6, the distal end surfaces of the light projecting and receiving optical fiber strands 10 and 12 and the proximal end surface of the quartz glass member 3c are in surface contact. The proximal end portion of the quartz glass member 3c and the distal end portion of the parallel optical fiber 17 are fixed inside the coupling member 6.

  In FIG. 5, reference numeral 17a denotes a coating on the parallel optical fiber 17 used for both light projection and reception. Other configurations are the same as those shown in FIG. 4, and the same components are denoted by the same reference numerals.

  According to the present embodiment, when detecting the presence or absence of the detection object 5 in the required detection region 4 set in the quartz box 1 that is clean and in a high temperature environment, the reflection type light is used. The light 13 guided from the light source of the sensor body of the fiber sensor 8 through the light projecting optical fiber 10 of the parallel optical fiber 17 is the front end surface of the light projecting optical fiber 10 as a light projecting portion ( Output (project light) from the light projection surface. As in the embodiment shown in FIG. 4, the output light 13 is incident from the base end face of the quartz glass member 3c, and is efficient in a state where light loss is suppressed in the quartz glass member 3c. The light is often guided to the front end surface in the vicinity of the detection region 4 and is projected toward the detection region 4 from the front end surface of the quartz glass member 3a on the light projecting side. Further, as shown by a two-dot chain line in FIG. 5, the reflected light 13a of the projected light 13 generated when the detected object 5 is present in the detected area 4 is located in the vicinity of the detected area. The incident light enters the tip surface of the quartz glass member 3c. As a result, the reflected light 13a is efficiently guided to the base end face in the quartz glass member 3c while suppressing the loss of light, and the light receiving portion of the parallel optical fiber 17 from the base end face. Can be received on the tip surface of the light receiving optical fiber 12.

  Therefore, also in the present embodiment, the presence or absence of the detection object 5 in the detection region 4 in the quartz box 1 that is in a clean environment and in a high temperature environment is detected by the photodetector of the sensor body via the optical fiber 12 for light reception. Can be detected based on the change in the amount of received light detected at. At this time, the light 13 projected from the tip of the projecting optical fiber 10 in the parallel optical fiber 17 serving as the projecting unit of the reflective optical fiber sensor 8 is present in the detection region 4. The reflected light 13a is reflected by the body 5, and the reflected light 13a is received by the tip of the light receiving optical fiber 12 in the parallel optical fiber 17 as the light receiving portion of the reflective optical fiber sensor 8. On the path, the projected light 13 and the reflected light 13a from the detected object 5 do not pass through the window, and do not pass through the space between the detection region 4 and the window. For this reason, the effect similar to embodiment shown in FIG. 4 can be acquired.

  Next, FIG. 6 shows an application example of the embodiment shown in FIG. 5. In a configuration similar to that shown in FIG. 5, a quartz glass member 3c used for both light transmission and reception is attached to a quartz box 1 of an annealing furnace. Instead of a configuration in which the side wall 1a is disposed inside the furnace so as to protrude to the vicinity of the required detection region 4, a detection target such as a glass substrate with a silicon film to be heat-treated in the quartz box 1 is provided. In order to hold the body 5 at a required height position, one of the quartz pins 18 for supporting a workpiece, which is erected on the bottom of the furnace, can be used as a quartz glass member.

  That is, a required position of the bottom plate 1b of the quartz box 1, that is, on the bottom plate 1b, is erected on the bottom plate 1b in a required arrangement so as to correspond to the four corners, the four corners and the center, and the like. For example, an opening 2 is provided at a position corresponding to the center portion of the detection object 5 in accordance with the arrangement of the quartz pins 18 for supporting the workpiece, and the opening 2 is provided inside and outside the furnace in the same manner as shown in FIG. A pipe-shaped coupling member 6 is attached so as to penetrate in the direction. On the upper end side, which is the inside of the furnace of the coupling member 6, the upper and lower end surfaces are polished in a plane perpendicular to the cylinder axis direction, with the upper end reaching the same height position as the other quartz pins 18. A lower end portion of a certain quartz glass member 3d is inserted to hold the quartz glass member 3d, and light is projected onto the lower end side, which is the outside of the furnace of the coupling member 6, as shown in FIG. The distal end portion of the parallel optical fiber 17 polished so that the distal end surface of each of the optical fiber strands 10 and 12 for receiving and receiving becomes a plane perpendicular to the axial direction is inserted and arranged, and the coupling member 6 Of the optical fiber strands 10 and 12 for projecting and receiving light of the parallel optical fiber 17 on the lower end surface of the quartz glass member 3d on the inner side in the vertical direction. In the surface contact state, the inside of the coupling member 6 The lower end of the quartz glass member 3d and is obtained so as to fix the tip end portion of the parallel optical fiber 17.

  In the present embodiment, the detection object 5 is placed and supported on the upper side of the quartz glass member 3d. Therefore, the detection region 4 for detecting the presence or absence of the detection object 5 is the quartz glass. The position is directly above the member 3d. Other configurations are the same as those shown in FIG. 5, and the same components are denoted by the same reference numerals.

  In the present embodiment, the same effect as in the above embodiment can be obtained, and furthermore, the quartz glass member 3d is to be detected in the quartz box 1 in the same manner as the other quartz pins 18. It can be used as a supporting member for supporting the body 5. As described above, when the object to be detected 5 is supported on the upper side of the quartz glass member 3d, the upper end surface (tip surface) of the quartz glass member 3d and the object to be detected 5 can be brought into contact with each other. The light 13 projected from the front end surface of the glass member 3d to the detection region 4 and the reflection reflected by the detection target 5 existing in the detection region 4 and received by the upper end surface of the quartz glass member 3d. It is possible to further shorten the optical path when the light 13a passes through the space.

  Next, FIG. 7 shows a modified example of the embodiment shown in FIG. 5 as still another embodiment of the present invention. The light beam inside the side wall 1a of the quartz box 1 of the annealing furnace shown in FIG. In place of the configuration in which the wave member is the quartz glass member 3c, the light projecting and receiving optical fiber elements in which the coating 17a of the parallel optical fiber 17 for both projecting and receiving light similar to that shown in FIG. The wires 10 and 12 are used as optical waveguide members.

  Specifically, an opening 2 is provided on the side wall surface of the quartz box 1 in the same manner as shown in FIG. 5, and the opening 2 has a heat resistant material that does not cause metal contamination or dust generation, such as ceramic or glass. The attachment member 19 formed by the above is fitted and attached. A fiber mounting recess 20 having a diameter substantially the same as the diameter of the parallel optical fiber 17 and having a required depth is provided on one side surface of the mounting member 19 which is the outside of the furnace. Fiber strand insertion holes 21a and 21b through which the optical fiber strands 10 and 12 for projecting and receiving light of the parallel optical fiber 17 are inserted are formed in the inner bottom surface of the optical fiber 20.

  The parallel optical fiber 17 is made of quartz glass for the optical fiber wires 10 and 12 for projecting and receiving light, and by removing the coating 17a at the tip, each of the projecting and receiving optical fibers 17 and 12 is made. The optical fiber strands 10 and 12 are exposed over a required length. The portions of the parallel optical fiber 17 from which the coatings 17a of the optical fiber strands 10 and 12 are removed are inserted into the fiber strand insertion holes 21a and 21b of the mounting member 19, respectively. The distal end portion of the coating 17a of the parallel optical fiber 17 is fitted into the fiber mounting recess 20 of the mounting member 19 and fixed. Further, the attachment member 19 to which the tip of the coating 17a of the parallel optical fiber 17 is attached is fitted into the opening 2 of the one side wall 1a of the quartz box 1, thereby attaching the attachment member 19 to the attachment member 19. The front end surfaces of the light projecting and receiving optical fiber strands 10 and 12 projecting into the furnace through the fiber strand insertion holes 21a and 21b are positioned in the vicinity of the required detection region 4 inside the quartz box 1. And reaches the detection area 4.

  Other configurations are the same as those shown in FIG. 5, and the same components are denoted by the same reference numerals.

  According to the present embodiment, the light 13 guided from the light source of the sensor body through the light projecting optical fiber 10 to the position of the one side wall 1a of the quartz box 1 has the coating 17a removed in the quartz box 1. Then, the light is continuously propagated to the vicinity of the detection region 4 where the distal end surface of the light projecting optical fiber 10 is located by the light projecting optical fiber 10 arranged in the step, and then the light is projected. Light is projected toward the detection region 4 from the front end surface (light projecting surface) of the optical fiber strand 10 for use. When the detection object 5 exists in the detection area 4 and the reflected light 13a is generated by the detection object 5, the reflected light 13a is received in the quartz box 1 with the coating 17a removed. Light is received at the front end surface (light receiving surface) of the optical fiber strand 12 for use at a position near the detection region 4, guided to the outside of the quartz box 1 through the optical fiber strand 12 for light reception, and as it is. Then, the light is guided to the light detection unit of the sensor body.

  Therefore, also in the present embodiment, as in the embodiment shown in FIG. 5, the presence or absence of the detection object 5 in the detection region 4 in the quartz box 1 in a clean environment and in a high temperature environment is determined by the light for receiving light. Detection is possible based on a change in the amount of received light detected by the photodetector of the sensor body through the fiber strand 12.

  Moreover, since the fiber strand insertion holes 21a and 21b are provided in the mounting member 19 so that only the optical fiber strands 10 and 12 for light projection and light reception are inserted, The coating 17a of the parallel optical fiber 17 is not exposed. For this reason, also in the present embodiment, as in the embodiment shown in FIG. 5, it is possible to accurately detect the presence or absence of the detection target 5 in the detection region 4 in a clean environment and in a high temperature environment. . Further, it is possible to eliminate the necessity of separately preparing a quartz glass member 3c as an optical waveguide member as shown in FIG. 5, and it is possible to make it advantageous for cost reduction.

  In the above description, the opening 2 is provided in one side wall 1a of the quartz box 1, and the mounting member 19 having the fiber mounting recess 20 and the optical fiber strand insertion holes 21a and 21b in the opening 2 is provided. It is shown that the tip of the parallel optical fiber 17 is attached to the fiber, but the fiber strand insertion holes 21a and 21b are provided on the inner bottom surface on the outer surface of the one side wall 1a of the quartz box 1 in the same manner as the attachment member 19 is provided. The fiber mounting recess 20 is directly provided, and the fiber mounting recess 20 is stripped of the coating 17a at the tip, and the optical fiber strands 10 and 12 for projecting and receiving light have the required length. You may make it attach directly the front-end | tip part of the parallel type optical fiber 17 exposed over.

  FIG. 8 shows another modified example of the embodiment shown in FIG. 5 as still another embodiment of the present invention. In the inner side of one side wall 1a of the quartz box 1 of the annealing furnace shown in FIG. Instead of the configuration in which the optical waveguide member is an elongated cylindrical quartz glass member 3c, an elongated cylindrical hollow waveguide member 22 is used as the optical waveguide member.

  That is, as shown in FIG. 5, an opening 2 is provided at a required portion of the quartz box side wall 1a, the outer diameter of the opening 2 is the same as the inner diameter of the opening 2, and the inner diameter is parallel to the parallel. The connecting member 6 formed in a pipe shape having a required length and the same size as the outer diameter of the mold optical fiber 17 is inserted, and both end portions in the axial center direction of the connecting member 6 are respectively required in the inside and outside of the furnace. It protrudes so as to be fixed to the opening 2.

  Similar to the quartz glass member 3c, the hollow waveguide member 22 is made of a material having high temperature resistance and no risk of metal contamination and low dusting property, for example, quartz glass. The optical fiber 17 has an elongated cylindrical shape having the same outer diameter. By making the inner wall surface function as a light reflecting surface, the light incident on the inner space from one end can be reflected on the inner wall surface. However, it is possible to guide the other end through the internal space with low loss. Further, the hollow waveguide member 22 has the opening at the tip reaching the position near the required detection region 4 inside the quartz box 1 and is disposed so as to face the detection region 4. The base end portion of the waveguide member 22 is inserted and held inside the protruding portion of the coupling member 6 toward the furnace inside.

  In the parallel optical fiber 17, the light projecting and light receiving optical fibers 10, 12 are made of quartz glass as described above, and the opening 17 on the base end side of the hollow waveguide member 22 is covered with 17 a. In order to prevent the exposure, the coating 17a of the tip portion is removed over a required dimension, and the tip portions of the light projecting and receiving optical fiber strands 10 and 12 are exposed (projected) short, respectively. The shielding member 23 is disposed on the exposed end portion of the optical fiber strands 10 and 12. The shielding member 23 is a disk having an outer diameter similar to that of the parallel optical fiber 17 formed of a material having high temperature resistance such as quartz glass and ceramics and having no risk of metal contamination and low dust generation. Fiber strand insertion holes 24a and 24b are formed at locations corresponding to the optical fiber strands 10 and 12, respectively, and each fiber strand insertion hole provided in the shielding member 23 is formed. The protruding portions of the optical fiber strands 10 and 12 from which the coating 17a at the tip end portion of the parallel optical fiber 17 is removed are fitted into 24a and 24b, respectively. Thus, the tip surface side of the coating 17a at the tip portion of the parallel optical fiber 17 can be covered with the shielding member 23, and the tip portions of the optical fiber strands 10 and 12 are It can be exposed through the fiber strand insertion holes 24a, 24b of the shielding member 23.

  Since it has the above configuration, the tip of the parallel optical fiber 17 with the shielding member 23 attached to the tip is inserted into the protruding portion of the coupling member 6 toward the outside of the furnace. The tip end of the fiber 17 is held by the coupling member 6, and the tip surfaces of the light projecting and receiving optical fiber strands 10 and 12 are located inside the coupling member 6. The hollow waveguide member 22 is exposed to the inside of the opening on the proximal end side, and the proximal end portion of the hollow waveguide member 22 and the parallel optical fiber 17 are disposed inside the coupling member 6. The tip is fixed.

  Other configurations are the same as those shown in FIG. 5, and the same components are denoted by the same reference numerals.

  According to the present embodiment, the light 13 guided from the light source of the sensor body through the light projecting optical fiber 10 to the side wall 1a position of the quartz box 1 is transmitted from the tip of the light projecting optical fiber 10. The light is projected and enters the internal space of the hollow waveguide member 22 through the proximal end side opening. The light 13 incident on the internal space of the hollow waveguide member 22 is propagated through the internal space to the tip end side in the axial direction with low loss using reflection on the inner wall surface of the hollow waveguide member 22. After that, light is projected toward the detection region 4 from the opening on the front end side of the internal space. When the detection object 5 is present in the detection area 4 and the reflected light 13a is generated by the detection object 5, the reflected light 13a is transmitted to the internal space of the hollow waveguide member 22 at a position near the detection area 4. Is incident through the opening on the tip side. The reflected light 13a incident on the inner space of the hollow waveguide member 22 from the front end side is reflected in the inner wall surface of the hollow waveguide member 22 and is axially centered in the inner space. Is transmitted to the base end side in the direction with low loss, and then received by the front end surface of the light receiving optical fiber 12 of the parallel optical fiber 17 exposed at the opening on the base end side of the internal space, The light is detected by being guided to the light detection portion of the sensor body through the light receiving optical fiber 12.

  Therefore, also in the present embodiment, as in the embodiment shown in FIG. 5, the presence or absence of the detection object 5 in the detection region 4 in the quartz box 1 in a clean environment and in a high temperature environment is determined as the light for receiving light. Detection can be performed based on a change in the amount of received light detected by the photodetector of the sensor body via the fiber strand 12, and the same effect as shown in FIG. 5 can be obtained.

  By the way, in each of the embodiments shown in FIGS. 1, 2, 3, 4 (A), (B), 5, 6, 7, and 8, the reflective optical fiber sensor 8 is used. When the detected object 5 does not exist in the detection region 4, the amount of light detected by the photodetector of the sensor main body through the light receiving optical fiber 12 is the amount of light received only in the background. On the other hand, based on the principle that when the detection object 5 is present in the detection area 4, the received light amount is obtained by adding the reflected light 13 a from the detection object 5 to the background light. 4 indicates that the presence or absence of the detected object 5 is detected based on a change in the amount of received light detected by the photodetector of the sensor body via the light receiving optical fiber 12. The amount of the reflected light 13a produced by the In view of the fact that light can be received as a large amount of light at locations close to each other and the amount of light that can be received decreases as the distance from the detection object 5 increases, the light is detected by the photodetector of the sensor body. Based on the increase / decrease in the amount of received light, the detection region 4 is made to detect the behavior of the detected object 5 in the proximity and separation direction with respect to the place where the light projecting unit and the light receiving unit of the reflective optical fiber sensor 8 are installed. May be.

  That is, for example, when the detection object 5 is carried into and out of the detection region 4 in the quartz box 1 of the annealing furnace, the detection object 5 is carried in between the detection region 4, As a configuration in which the light projecting portion and the light receiving portion of the reflection type optical fiber sensor 8 are disposed on the other side, which is the side facing the carry-out side, with an optical waveguide member interposed between one or both of them. When the detected object 5 is carried into the detection area 4, the detected object 5 gradually approaches the light projecting part and the light receiving part of the reflective optical fiber sensor 8, while the detected object 5 is in the detection area. 4, when the detection object 5 is gradually separated from the light projecting part and the light receiving part of the reflective optical fiber sensor 8, the detection area 4 detected by the light receiving part is detected. Reflected light 13a by the body 5 When the amount of light exceeds a predetermined threshold value, it is determined that the detection object 5 is present at a position closer to the light receiving unit than a certain distance. By determining that the detection body 5 exists at a position separated from the light receiving unit by a certain distance, it is determined whether or not the detection object 5 is closer to the light receiving unit than the certain distance. Thus, the detection target 5 may be used for detecting the behavior. Furthermore, by setting a plurality of threshold values that are different in size in advance, the positional relationship with the light receiving unit of the detected object 5 is made closer to the distance on the basis of a certain distance in the same manner as described above. Whether or not the light quantity of the reflected light 13a of the detected object 5 exceeds each of the set threshold values. By determining each of these, the positional relationship between the detected object 5 and the light receiving unit can be detected based on a plurality of distance levels, and the detected object 5 is based on the detected change in distance level. You may make it detect the approach of the proximity | contact with respect to a light-receiving part, and the separation direction.

  Further, monochromatic light having a predetermined frequency is projected from the light projecting unit of the reflective optical fiber sensor 8, and in this state, the reflected light 13a received by the detected body 5 received by the light receiving unit is described above. By detecting a change in frequency from the projected light, it is possible to detect the behavior of the detected object 5 in the proximity direction or the separation direction with respect to the projecting portion and the light receiving portion of the reflective optical fiber sensor. It is also possible.

  FIG. 9 shows a case where sensing is performed using a transmission type optical fiber sensor 8a having a light projecting part and a light receiving part as separate optical sensors as still another embodiment of the present invention.

  That is, it is set in the quartz box 1 on the side wall facing the front-rear direction or the left-right direction of the quartz box 1 of the annealing furnace, or on the ceiling wall and the floor plate (shown as the side wall 1a in the left-right direction in the drawing). Openings 2 are respectively provided at two locations facing each other with a required detection region 4 interposed therebetween, and pipe-like coupling members 6a, 6b similar to the coupling members 6a, 6b shown in FIG. 6b, and a quartz glass member 3a similar to that shown in FIG. 3 with the tip portion reaching the position in the vicinity of the detection region 4 at the protrusion inside the furnace of each coupling member 6a, 6b. The base end side of 3b is set to be inserted and arranged individually.

  Furthermore, the base end side is connected to the light source of the sensor main body (not shown) in the transmission type optical fiber sensor 8a installed in the external required position on the protrusion outside the furnace of the one coupling member 6a. The tip end surface of the light projecting optical fiber 25 is inserted and held as a light projecting portion which is polished so as to be a plane perpendicular to the axial direction. The inner surface of the coupling member 6a is in surface contact with the base end surface of the quartz glass member 3a, and the quartz glass member is disposed on the inner side of the coupling member 6a as in FIG. The base end portion 3a and the tip end portion of the light projecting optical fiber 25 are fixed together.

  Further, the distal end portion of the light receiving optical fiber 27 having the proximal end connected to the photodetector of the sensor body is inserted and held in the projecting portion outside the furnace of the other coupling member 6b. The tip surface of the light receiving optical fiber 28 as a light receiving portion polished so as to be a plane perpendicular to the axial direction is inside the intermediate portion of the coupling member 6b, and the quartz glass member 3b. The base end face is brought into surface contact, and the base end portion of the quartz glass member 3b and the front end portion of the light receiving optical fiber 27 are fixed inside the coupling member 6b in the same manner as described above. . As a result, the tip surfaces of the quartz glass members 3a and 3b attached to the coupling members 6a and 6b face each other with the detection region 4 in between.

  In FIG. 9, reference numeral 25 a indicates the coating of the light projecting optical fiber 25, and 27 a indicates the coating of the light receiving optical fiber 27. Other components that are the same as those shown in FIG.

  When the presence or absence of the detected object 5 in the detection region 4 in the quartz box 1 is detected by the sensing device in the present embodiment, the light 13 guided from the light source of the sensor body through the light projecting optical fiber 25 is The light is guided to the quartz box 1 through the quartz glass member 3a on the projection side connected to the tip side of the light projecting optical fiber 25, and the high light transmittance and total reflection of the quartz glass member 3a are utilized. After guiding to the tip surface (light projecting surface) of the quartz glass member 3a that is in the vicinity of the detection region 4 in the quartz box 1 while suppressing light loss, the detection region is detected from the light projecting surface of the quartz glass member 3a. Light is projected toward 4. As a result, when the detection target 5 is not present in the detection region 4, the light projected toward the detection region 4 passes through the detection region 4 and then sandwiches the detection region 4 therebetween. The light is received at the front end surface (light receiving surface) of the light receiving side quartz glass member 3b disposed in the vicinity of the light emitting side quartz glass member 3a and in the vicinity of the detection region 4. The light is guided to the position of the opening 2 formed in the wall surface of the quartz box 1 while suppressing the loss of light by utilizing the high light transmittance and total reflection of the quartz glass member 3b, and then the light reception. The light is transmitted to the light receiving optical fiber 27 attached to the base end side of the quartz glass member 3b on the side, and is transmitted to the light detection unit in the sensor body through the light receiving optical fiber 27 so that the light quantity is detected.

  On the other hand, as shown by a two-dot chain line in FIG. 9, when the detection object 5 exists in the detection region 4, the detection region 4 passes through the quartz glass member 3 a on the light projecting side from the light projecting optical fiber 25. Then, the light 13 projected from the projection surface of the quartz glass member 3a toward the detection region 4 is blocked or reflected by the detected object 5 existing in the detection region 4. When the detected object 5 is translucent, a part of the projected light 13 is absorbed. For this reason, the amount of light received by the tip surface (light receiving surface) of the quartz glass member 3b on the light receiving side is reduced, and is detected by the photodetector of the sensor body through the quartz glass member 3b and the light receiving optical fiber 27. The amount of light emitted is reduced.

  Therefore, based on whether or not the amount of received light detected by the photodetector of the sensor main body via the light receiving optical fiber 27 is reduced from the initial state, the detection area 4 in the quartz box 1 is covered with the detection area 4. Whether or not the detector 5 is present can be detected in the same manner as a conventional transmission optical fiber sensor.

  Also in the present embodiment, as in the embodiment of FIG. 3, in the quartz box 1, quartz glass members 3a and 3b and a coupling member 6a made of a heat-resistant material that does not cause metal contamination and dust generation. , 6b is exposed, the presence or absence of the detection object 5 in the detection region 4 set in the quartz box 1 of the annealing furnace that is clean and in a high temperature environment has an influence on the clean and high temperature environment. Can be detected without any problem.

  Further, the light 13 output from the light projecting optical fiber 25 is efficiently guided to the vicinity of the detection region 4 through the quartz glass member 3a on the light projecting side, and directed toward the detection region 4 from the tip surface of the quartz glass member 3a. After the light 13 transmitted through the detection region 4 is received by the tip surface of the quartz glass member 3b on the light receiving side that is in the vicinity of the detection region 4, the light receiving surface of the light receiving optical fiber 27 is efficiently received. As in the embodiment of FIG. 3, there is no window on the light path on the light emitting side and the light receiving side, and therefore the detected object 5 exists in the detection region 4. The range of increase / decrease in the amount of light when it is present and when it is not present can be expanded. When the detected object 5 is present in the detection region 4, the tip surface that is the light receiving surface of the quartz glass member 3b on the light receiving side is located in the vicinity of the detection region 4, so that the detection is performed. The distance between the detected object 5 that blocks the light 13 in the region 4 and the light receiving surface can be made closer, and the possibility of being affected by disturbance can be suppressed, and the S / N can be increased. Therefore, it is possible to accurately detect the presence or absence of the detection object 5 in the detection region 4 in a clean environment as in the quartz box 1 and in a high temperature environment.

  FIG. 10 shows still another embodiment of the present invention. In the same configuration as in FIG. 5, instead of using the reflective optical fiber sensor 8 as the optical sensor, a reflective regression optical fiber sensor 8b is used. This shows a case where sensing is performed using.

  That is, as shown in FIG. 5, the quartz glass member 3 c for both light and light used for light projection and reception is arranged in the opening 2 provided on the side wall 1 a of the quartz box 1 so as to protrude toward a required detection region in the quartz box 1. In a configuration in which a proximal end portion and a distal end portion of a parallel optical fiber 17 used for light projection and reception for performing light projection and reception with respect to the proximal end portion of the quartz glass member 3 c are attached via a coupling member 6. In the quartz box 1, a mirror-like reflecting plate 29 is provided at a position facing the tip surface (light projecting surface) of the quartz glass member 3 c with the detection region 4 interposed therebetween. Thus, when the detection object 5 does not exist in the detection region 4, the light projecting optical fiber strand of the parallel optical fiber 17 from the light source of the sensor body is the same as described in the embodiment of FIG. 10 through the quartz glass member 3c to a position near the detection region 4 in a state in which the loss of light is suppressed, and toward the detection region 4 from the tip surface serving as the light projection surface of the quartz glass member 3 The light 13 to be projected is allowed to pass through the detection region 4 and then reflected by the reflecting plate 29. The reflected light passes again through the detection region 4, and is then applied to the tip surface of the quartz glass member 3c. It is designed to receive light.

  Other configurations are the same as those shown in FIG. 5, and the same components are denoted by the same reference numerals.

  Therefore, according to the present embodiment, as shown by a two-dot chain line in FIG. 10, when the detection object 5 is present in the detection region 4, the light 13 and the reflector that have passed through the detection region 4. Since the light reflected by the light 29 is blocked and the amount of light received decreases, the amount of light received detected by the light detector of the sensor body is the same as in the case of using the transmission optical fiber sensor 8a of FIG. Whether or not the detected object 5 is present in the detection region 4 in the quartz box 1 can be detected based on whether or not it is decreased from the initial state. Therefore, the present embodiment can provide the same effects as those of the embodiment shown in FIG.

  Next, the internal environment in which the detection region 4 where the presence / absence of the detected object 5 is to be detected is one of an environment in which light loss is likely to occur when sensing from the outside using an optical fiber sensor, a high temperature environment, and a clean environment. A case where the environment has one or two features will be described. In this case, in the same structure as each embodiment of FIG. 1, FIG. 2, FIG. 3, FIG. 4 (A) (B), FIG. 5, FIG. 6, FIG. 7, FIG. If the wave member is made of a material having a high light transmittance, it can be expected that light loss in the process of projecting and receiving light from the optical fiber sensor to the detection region 4 can be suppressed, and the optical waveguide member can be heated at a high temperature. If it is made of a material having resistance, it can be easily applied when the internal environment in which the detection region 4 is set is a high temperature environment, and the optical waveguide member has no risk of metal contamination and low dust generation. If the material is made of a material, the detection area 4 can be easily applied when the internal environment in which the detection area 4 is set is a clean environment in which metal contamination and dust generation should be prevented. 4. High light transmittance and high according to the characteristics of the internal environment Resistance, it is sufficient to appropriately selected and used material made of optical waveguide member having any one or two characteristics of that characteristic is low dusting.

  Note that the present invention is not limited to only the above-described embodiments. For example, in each embodiment shown in FIG. 1, FIG. 2, FIG. 3, FIG. 4 (A) (B), FIG. 5, FIG. 6, FIG. The base end surfaces of 3c and 3d and the end surfaces of the optical fiber strands 10, 12, 26, and 28 of the optical fibers 9, 11, 17, 25, and 27 are polished so as to be a plane perpendicular to the axial direction. However, light is propagated between the optical fiber strands 10, 12, 26, 28 and the ends of the quartz glass members 3, 3a, 3b, 3c, 3d on the external environment side. Sometimes, if the desired propagation efficiency is obtained, the end portions of the optical fiber strands 10, 12, 26, 28 at the ends of the quartz glass members 3, 3a, 3b, 3c, 3d on the external environment side, Arrange them so that they have a slight gap between them, or connect them Surface may not become a little plane. Further, in FIGS. 1, 2, 3, 5, 6, 8, 9, and 10, quartz glass members 3, 3a, 3b, 3c, and 3d are provided in the opening 2 provided in the quartz box 1. The base end portion of the optical fiber 9 and the tip end portions of the optical fibers 9, 11, 17, 25, 27 are shown as being attached together via the coupling members 6, 6 a, 6 b. If only the glass members 3, 3 a, 3 b, 3 c, 3 d are exposed, for example, the base end portion serving as the end portion of the quartz glass members 3, 3 a, 3 b, 3 c, 3 d on the external environment side is made of quartz. The box 1 may be disposed so as to pass through the partition walls such as the side wall 1a and the bottom plate 1b of the box 1 and to protrude to the outside. Further, as described above, the base of the quartz glass members 3, 3a, 3b, 3c, 3d The end penetrates through the partition wall such as the side wall 1a and the bottom plate 1b of the quartz box 1 and protrudes to the outside. And arranged so as to, quartz glass member 3, 3a, 3b, 3c, a proximal end portion of 3d, it may be attached directly to the partition wall quartz box 1. Further, as described above, the quartz glass members 3, 3a, 3b, 3c, and 3d are arranged so as to protrude through the partition walls such as the side wall 1a and the bottom plate 1b of the quartz box 1 so as to protrude to the outside. Alternatively, the coupling members 6, 6 a, 6 b may be omitted, and the tip portions of the optical fibers 9, 11, 17, 25, 27 may be directly attached. In this case, the distal end surfaces of the optical fiber strands 10, 12, 26, and 28 of the optical fibers 9, 11, 17, 25, and 27 are disposed on the proximal end surfaces of the quartz glass members 3, 3a, 3b, 3c, and 3d. You may make it connect by welding often used for the connection of strands. Further, the quartz glass members 3, 3 a, 3 b, 3 c and 3 d are made of a single quartz glass, and the difference in refractive index between the quartz glass members 3 and 3 a and the internal atmosphere of the quartz box 1. Based on the above, it has been described as causing total reflection on the side surface of the cylinder, but the axial center portion is provided with a core portion made of transparent quartz glass, and the outer periphery thereof is provided with a cladding portion having a lower refractive index. The total reflection may be caused at the boundary surface between the core portion and the cladding portion.

  Although the parallel type optical fiber 17 is shown as the optical fiber for light transmission and reception in each of the embodiments of FIGS. 5, 6, 8, 9, and 10, a coaxial type or a split type optical fiber is used. You may do it. The optical fiber in the embodiment of FIG. 7 is a coaxial optical fiber as long as each optical fiber for light transmission and reception has a strength capable of maintaining the shape even without a coating. Also good. Furthermore, in each of the embodiments shown in FIGS. 1, 2, 9, and 10, the optical fiber 17 shown in FIG. 7 is used instead of the optical waveguide member made of quartz glass members 3, 3a, 3b, and 3c. As in the case of the optical fiber wires 10 and 12, the coatings 9a, 11a, 17a, 25a, and 27a at the tips of the optical fibers 9, 11, 17, 25, and 27 are removed and exposed for a required length. Further, the optical fiber strands 10, 12, 26, 28 may be used as an optical waveguide member.

  In the embodiment of FIG. 9, the quartz glass members 3 a and 3 b that protrude to the position near the detection region 4 in the quartz box 1 are provided on both the light projecting side and the light receiving side. Either the quartz glass member 3a or 3b on the light receiving side may be omitted. In this case, when the quartz glass member 3a on the light emitting side is omitted, the window 7 in the embodiment shown in FIG. 1 is formed on the side wall 1a facing the front end surface of the quartz glass member 3b on the light receiving side in the quartz box 1. The tip of the light projecting optical fiber 25 is installed outside the window, and passes through the detection region 4 to reach the tip surface (light receiving surface) of the quartz glass member 3b on the light receiving side. The light 13 may be projected through the window from the tip of the light projecting optical fiber 25. On the other hand, when the quartz glass member 3b on the light receiving side is omitted, the side wall 1a facing the front end surface of the quartz glass member 3a on the light projecting side in the quartz box 1 and the window 7 in the embodiment shown in FIG. A similar window is provided, the tip of the light receiving optical fiber 27 is installed outside the window, and the light 13 that is projected from the tip of the quartz glass member 3a on the light projecting side and passes through the detection region 4 is transmitted. The light receiving optical fiber 27 may receive light through the window at the distal end. In this way, even when either the light emitting side or the light receiving side of the quartz glass member 3a or 3b is omitted, the remaining light receiving side or the light projecting side is configured to pass the light path through the quartz glass member 3b or 3a. By passing the light, loss of light quantity can be suppressed, and the distance through the space can be shortened to prevent noise from entering. Therefore, as compared with the case where both the light projecting side and the light receiving side are provided outside the quartz box 1, the range of increase / decrease in the amount of light when the detection target exists in the detection region and when it does not exist can be expanded. At the same time, the S / N ratio of the light to be detected can be increased, and the detection accuracy of the presence or absence of the detection object in the detection region can be improved.

  9 shows either the quartz glass member 3a or 3b provided on the light projecting side and the light receiving side of the transmission optical fiber sensor in the embodiment of FIG. 9, and the quartz glass member 3c in the embodiment of FIG. Similarly to the quartz glass member 3d shown in FIG. 6, these quartz members are constructed such that the upper end surface thereof stands up from the bottom plate 1b of the quartz box 1 so as to reach the detection region 4 and is arranged below the detection region. The glass members 3a, 3b, and 3c may be used as supporting members for placing and supporting the detected object 5 to be arranged in the detection region 4 on the upper side.

  The configurations of the light projecting unit and the light receiving unit in the reflection regression type optical fiber sensor 8b of FIG. 10 are shown in FIG. 1, FIG. 2, FIG. 3, FIG. As a configuration similar to the light projecting unit and the light receiving unit in the optical fiber sensor 8, a quartz glass member may be optically connected to one or both of the light projecting unit and the light receiving unit.

  1, 2, 3, 4 (b), (b), 5, 6, 9, and 10, quartz glass members 3, 3 a, 3 b, and 3 c are used as optical waveguide members. 3d, but it has high light transmittance, high temperature resistance, metal contamination is less than the allowable value and low dust generation, it can be used as alkali glass, transparent ceramic, and optical parts. A material other than quartz glass such as a crystal may be used. The shape of the optical waveguide member is an elongated cylindrical shape from the viewpoint of suppressing the loss of light by utilizing total reflection as shown as the shape of the quartz glass members 3, 3a, 3b, 3c, 3d. However, any shape may be adopted as long as the loss of light is less than the allowable value.

  The cylindrical hollow waveguide member 22 as the optical waveguide member in the embodiment of FIG. 8 is preferably an elongated cylindrical shape from the viewpoint of suppressing light loss by utilizing reflection on the inner wall surface. Any shape may be adopted as long as the loss is less than the allowable value.

  1, 2, 3, 4 (b), (b), FIG. 5, FIG. 6, FIG. 9, and FIG. Although 3a, 3b, 3c, 3d are shown, an elongated hollow waveguide member 22 similar to that shown in FIG. 8 may be used.

  As the optical sensor, the light projecting part and the light receiving part can be easily placed close to the external environment side ends of the quartz glass members 3, 3a, 3b, 3c, 3d as the optical waveguide members. From the viewpoint of efficiently transmitting light between the light projecting unit and the light receiving unit and the end portion of the optical waveguide member on the external environment side, the reflection type, transmission type, or reflection regression type optical fiber sensors 8, 8a. 8b, but using a general reflection type, transmission type or reflection regression type optical sensor, the light projecting part and the light receiving part of the optical sensor are connected to the corresponding quartz glass members 3, 3a, 3b, You may make it arrange | position so that the edge part by the side of the external environment of 3c, 3d may be faced.

  If it is desired to optically detect the presence or absence of an object to be detected in a required detection area set in a clean environment and / or a high temperature environment, a glass substrate with a silicon film in the process of manufacturing a liquid crystal panel The present invention can be applied to detection of an object to be detected in any detection region other than the detection region set inside the quartz box in the annealing furnace. Of course, various changes can be made without departing from the scope of the present invention.

As an embodiment of the sensing method and apparatus using the optical sensor of the present invention, a schematic cutting plane showing a case where the optical sensor is applied to a sensor that performs sensing using a separate reflection type optical fiber sensor with a light projecting unit and a light receiving unit. FIG. FIG. 10 is a schematic plan view showing another example of a case where the present invention is applied to an optical sensor that performs sensing using a reflection type optical fiber sensor in which a light projecting unit and a light receiving unit are separated from each other. . As still another embodiment of the present invention, a schematic cut plan view showing still another example of the case where the light sensor and the light receiving part perform sensing with a separate reflection type optical fiber sensor as an optical sensor. It is. As still another embodiment of the present invention, as a photosensor, a light-emitting unit and a light-receiving unit are shown as modified examples in which sensing is performed by a separate-type reflective optical fiber sensor. Is a schematic cut plan view, and (b) is a schematic view of the coupling member as seen from the outside of the furnace. As another embodiment of the present invention, it is a schematic cut plan view showing a case where the present invention is applied to an optical sensor that performs sensing with a reflection type optical fiber sensor in which a light projecting / receiving unit is integrated. As another embodiment of the present invention, it is a schematic cut side view showing an application example in the case of applying to a sensor that performs sensing by a reflection type optical fiber sensor in which a light projecting / receiving unit is integrated as an optical sensor. As another embodiment of the present invention, it is a schematic cut plan view showing a modification in the case of applying to sensing using a reflection type optical fiber sensor in which a light projecting / receiving unit is integrated as an optical sensor. As another embodiment of the present invention, it is a schematic cut plan view showing another modification when applied to a sensor that performs sensing by a reflection type optical fiber sensor in which a light projecting / receiving unit is integrated as an optical sensor. As another embodiment of the present invention, it is a schematic cut plan view showing a case where the present invention is applied to an optical sensor that performs sensing with a transmissive optical fiber sensor in which a light projecting unit and a light receiving unit are separated. It is a general | schematic cut-off top view which shows the case where it applies about what performs the sensing by a reflection regression type optical fiber sensor as an optical sensor as another form of implementation of this invention. It is a schematic diagram which shows an example of the reflection type optical fiber sensor for using in the high temperature environment proposed conventionally. It is sectional drawing which shows an example of the conventionally proposed heat-resistant optical fiber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Quartz box 1a Side wall 1b Bottom plate 3, 3a, 3b, 3c, 3d Quartz glass member (optical waveguide member)
DESCRIPTION OF SYMBOLS 4 Detection area | region 5 Detected object 8, 8a, 8b Optical fiber sensor 9 Optical fiber for light projection 9a Coating | coated 10 Optical fiber strand for light projection (light projection part)
DESCRIPTION OF SYMBOLS 11 Optical fiber for light reception 11a Covering 12 Optical fiber strand for light reception (light-receiving part)
13 light 13a reflected light 17 parallel optical fiber 17a coating 22 hollow waveguide member (optical waveguide member)
25 Optical fiber for projecting light 25a Coating 26 Optical fiber for projecting light (projecting unit)
27 Optical Fiber for Light Projection 27a Coating 28 Optical Fiber Wire for Light Projection (Light Projecting Unit)
29 Reflector

Claims (17)

  The light output from the light projecting portion of the optical sensor provided at a required location on the external environment side than the boundary between the clean and / or high temperature internal environment and the external environment is set in the required internal environment. When light is projected to the detection area and the reflected light of the projected light in the detection area is received by the light receiving unit of the photosensor, one or both of the projected light and the reflected light is received. Based on the change in the amount of light received by the light receiving portion of the photosensor, the light guide member guides between the position near the boundary and the detection area in the internal environment or the position near the detection area. A sensing method using an optical sensor, characterized by detecting the presence / absence and behavior of an object to be detected in the detection region.   The light output from the light projecting unit of the light sensor provided with the light projecting unit and the light receiving unit provided at a required location on the external environment side than the boundary between the clean and / or high temperature internal environment and the external environment, The light projecting on a required detection area set in the internal environment and reflected by a reflector provided on the opposite side of the light projecting part and the light receiving part of the optical sensor across the detection area When the reflected light of the emitted light is received by the light receiving portion of the photosensor, one or both of the projected light and the reflected light are detected in the vicinity of the boundary portion and the detection region in the internal environment. Or detecting the presence / absence of an object to be detected in the detection region based on a change in the amount of light received by the light receiving unit of the optical sensor. Sensing method using an optical sensor.   The light output from the light projecting portion of the optical sensor provided at a required location on the external environment side than the boundary between the clean and / or high temperature internal environment and the external environment is set in the required internal environment. When the light that is projected to the detection area and the light that passes through the detection area is received by the light receiving portion of the optical sensor provided on the external environment side, the light is projected and received through the detection area. One or both of the light to be transmitted is guided through an optical waveguide member between a position in the vicinity of the boundary portion and a detection region in the internal environment or a position in the vicinity of the detection region. A sensing method using an optical sensor, wherein the presence / absence of an object to be detected in the detection region is detected based on a change in the amount of received light.   4. An optical fiber sensor according to claim 1, wherein one or both of a light projecting portion and a light receiving portion is disposed so as to face an end portion on the external environment side of the optical waveguide member. Sensing method using sensors.   5. The sensing method using an optical sensor according to claim 1, wherein the optical waveguide member is made of a material having a high transmittance with respect to light projected from a light projecting portion of the optical sensor.   6. The sensing method using an optical sensor according to claim 1, 2, 3, 4, or 5, wherein an optical waveguide member made of a material having a high temperature resistance and / or a material having a low dusting property is used.   7. A sensing method using an optical sensor according to claim 1, wherein a member made of quartz glass is used as the optical waveguide member.   The light projecting unit projects light to the required detection area set in the internal environment above the boundary between the clean and / or high temperature internal environment and the external environment. An optical sensor is provided so that the reflected light of the projected light in the detection region can be received by the light receiving unit, and further, the light projected from the light projecting unit of the photo sensor and the light receiving unit of the photo sensor are provided. An optical waveguide member for guiding one or both of the reflected light to be received is provided between the position near the boundary and the detection area in the internal environment or the position near the detection area. Sensing device with a featured optical sensor.   A light sensor equipped with a light projecting part and a light receiving part is provided at a required location on the external environment side of the boundary between the clean and / or high temperature internal environment and the external environment, and is set in the above internal environment. The reflected light of the projected light is projected from the light projecting unit to the detection region of the light and is reflected by a reflector provided on the opposite side of the light projecting unit and the light receiving unit across the detection region. An optical waveguide member for guiding one or both of the light projected from the light projecting portion of the photosensor and the reflected light received by the light receiving portion of the photosensor, A sensing device using an optical sensor, having a configuration provided between a position near a boundary and a detection region under the internal environment or a position near the detection region.   Projecting from the light projecting unit to the required detection area set in the internal environment above the boundary between the clean and / or high temperature internal environment and the external environment on the external environment side An optical sensor is provided so that light passing through the detection region can be received by the light receiving unit, and further, the light projected from the light projecting unit of the photo sensor and the detection region received by the light receiving unit of the photo sensor are provided. An optical waveguide member for guiding one or both of the transmitted light is provided between a position near the boundary and a detection region in the internal environment or a position near the detection region. Sensing device with optical sensor.   11. The sensing by the optical sensor according to claim 8, 9 or 10, wherein the optical sensor is an optical fiber sensor in which one or both of the light projecting portion and the light receiving portion are arranged so as to face an end portion on the external environment side of the optical waveguide member. apparatus.   The optical waveguide member is disposed below the detection region, and an object to be detected disposed in the detection region can be placed and supported above the optical waveguide member. 11. A sensing device using the optical sensor according to 11.   13. The sensing device using an optical sensor according to claim 8, wherein the optical waveguide member is made of a material having a high transmittance with respect to light projected from a light projecting portion of the optical sensor.   14. The sensing device using an optical sensor according to claim 8, wherein the optical waveguide member is made of a material having high temperature resistance and / or a material having low dusting property.   The sensing device using an optical sensor according to claim 8, 9, 10, 11, 12, 13 or 14, wherein the optical waveguide member is made of quartz glass.   The sensing device using an optical sensor according to claim 8, 9, 10, 11, 12, 13, 14 or 15, wherein the optical waveguide member has an elongated cylindrical shape or an elongated cylindrical shape.   17. The sensing by the optical sensor according to claim 8, 9, 10, 11, 12, 13, 14, 15 or 16, wherein an optical fiber strand which is exposed by peeling off the coating of the optical fiber is used as the optical waveguide member. apparatus.

Images