JP2523975B2 - Displacement detection device - Google Patents

Description

The present invention relates to a displacement detection device that detects rotation or movement.

[Conventional technology]

Conventionally, many displacement detection devices have been considered as devices for detecting displacement such as rotation or movement of an object. Also, as a displacement detection device that detects the amount of rotation of the object, that is, the angular displacement
Compass and other gyro devices have been developed. In particular, various methods or mechanisms have been studied for gyro devices such as mechanical gyros and laser gyros. Further, an optical device such as an interferometric length measuring device has been developed as a displacement detecting device for detecting the amount of movement of an object.

[Problems to be Solved by the Invention]

However, no conventional displacement detection device that detects rotation or movement is simple and has relatively high accuracy.

On the other hand, as a displacement detection device that detects the angular displacement of an object,
For example, there is no conventional compass or the like that is small and highly accurate. Further, in the conventional gyro device, although the accuracy is high, the mechanism and structure are complicated, adjustment is not easy, and the gyro device requires careful handling. Further, the gyro device itself is large in size, difficult to handle, has limited uses, and is very expensive. The same situation occurs in the displacement detection device that detects the amount of movement of an object.

Therefore, in view of the above-mentioned circumstances, an object of the present invention is to provide a displacement detection device having an extremely simple structure, a small size, a light weight, and high accuracy.

[Means for solving the problem]

In order to achieve the above-mentioned object, in the first displacement detection device according to the present invention, (a) an excitation light source for irradiating excitation light to a phosphor whose displacement existing in a predetermined region is to be detected,
(B) Fluorescence detection means for detecting fluorescence from a fluorescent substance existing in a detection area corresponding to an area obtained by displacing the predetermined area in one or both of front and rear in a predetermined direction, and (c) output of the fluorescence detection means On the basis of the above, there is provided a displacement detecting means for detecting that the phosphor is displaced and whether the displacement direction is the front or back direction along the predetermined direction.

In order to achieve the above-mentioned object, in the second displacement detecting device according to the present invention, (a) a support member that can reciprocate along a predetermined direction, and (b) a support member is provided on the support member side. Together with an excitation light source for irradiating excitation light to the phosphor whose displacement existing in a predetermined region with respect to this support member is to be detected,
(C) Fluorescence detection means that is provided on the support member side and that detects fluorescence from a fluorescent substance that is present in a detection region corresponding to a region in which the predetermined region is displaced to one or both of the front and rear in the predetermined direction. , (D) displacement detecting means for detecting, based on the output of the fluorescence detecting means, that the phosphor is displaced with respect to the support member and whether the displacement direction is before or after the predetermined direction. And (c) a drive unit that displaces the support member in the displacement direction of the phosphor when the displacement detection unit detects the displacement of the phosphor, and (f) a displacement detection unit that detects the displacement amount of the support member. It is configured to be equipped.

In order to achieve the above-mentioned object, in the third displacement detecting device according to the present invention, (a) it is rotatable about a predetermined rotation axis provided on a displacement detection target member whose displacement is to be detected. A movable member having a phosphor on its surface, (b) a container that accommodates the movable member and is rotatable about the predetermined rotation axis, and (c) is provided on the container side. An excitation light source for irradiating a phosphor existing in a predetermined region in the container with excitation light, and (d) being provided on the container side and displacing the predetermined region in one or both directions around the predetermined rotation axis. Fluorescence detecting means for detecting fluorescence from the phosphor existing in the detection area corresponding to the made area, and (e) the movable member is rotationally displaced with respect to the container based on the output of the fluorescence detecting means, and The direction of displacement is within the specified rotation axis. (F) drive means for rotating the container in the displacement direction of the movable member when the displacement detection means detects the rotational displacement of the movable member, and (g) ) Displacement amount detecting means for detecting the rotational displacement amount of the container with respect to the displacement detection target member.

[Action]

According to the first displacement detection device of the present invention, the excitation light from the excitation light source is applied to the phosphor fixed on the surface of the object whose displacement is to be detected (hereinafter, referred to as “inspection object”). Is irradiated. In this case, since the excitation light is irradiated only in the predetermined region, only the predetermined irradiation site on the phosphor is excited. After that, when the phosphor is displaced along with the displacement of the object to be inspected, the above-mentioned irradiation site on the phosphor is also displaced accordingly. When the irradiated area on the phosphor is displaced by a predetermined amount or more and reaches the detection area, an increase or decrease in fluorescence from this detection area is detected by the fluorescence detection means. The displacement detecting means detects displacement of the irradiated portion, that is, the object to be inspected, and the displacement direction based on the detected increase / decrease in fluorescence.

According to the second displacement detecting device of the present invention, the excitation light is applied to the irradiation target portion of the phosphor fixed to the test object. When the phosphor is displaced along with the displacement of the object to be inspected, the irradiation site on the phosphor is also displaced. The fluorescence detecting means detects fluorescence from the detection area corresponding to an area obtained by displacing the predetermined area where the irradiation site originally existed in one or both of the front and rear in the predetermined direction. The displacement detection means, by monitoring the increase or decrease in the amount of light detected by this fluorescence detection means,
It is detected that the phosphor, that is, the object to be inspected is displaced along the predetermined direction and the direction of the displacement. The driving means immediately displaces the support member supporting the excitation light source and the fluorescence detection means so as to follow the direction in which the phosphor is displaced, and the state before the positional relationship between the support member and the phosphor is deviated Return to. The displacement amount detecting means detects the amount of displacement of the support member, and detects the amount of displacement of the phosphor (that is, the object to be inspected) corresponding to the amount of displacement of the support member.

According to the third displacement detecting device of the present invention, the excitation light is irradiated to the irradiated portion of the phosphor on the movable member. When the phosphor rotates together with the movable member, the irradiated portion on the phosphor also rotates. The fluorescence detecting means detects the fluorescence from the detection area obtained by displacing the predetermined area along the predetermined direction. Therefore, when the irradiated area on the phosphor is displaced by a predetermined amount or more and reaches the detection area, the increase or decrease in the fluorescence from the detection area is detected by the fluorescence detection means. The displacement detecting means detects that the movable member has rotated along the predetermined rotation axis and its direction by monitoring the increase or decrease in the amount of light detected by the fluorescence detecting means.
The driving means immediately rotates the container supporting the excitation light source and the fluorescence detecting means so as to follow the direction in which the phosphor, that is, the movable member, is rotated, and the state before the positional relationship between the container and the movable member is displaced is generated. Return to. The displacement amount detecting means detects the relative rotation amount of the container with respect to the displacement detection member, and detects the displacement amount of the displacement detection device, that is, the displacement detection device itself.

〔Example〕

Before starting the description of the embodiments, the principle of detecting the movement of the fluorescent substance by detecting the amount of fluorescent light emitted from the fluorescent substance will be briefly described with a few examples.

First, consider a case where the detection region in which fluorescence from the phosphor is to be detected is a region in which a predetermined region to which the phosphor is to be irradiated with excitation light is slightly displaced forward in a predetermined direction.

For example, assume that the excitation light from the excitation light source is pulse-wise irradiated to the phosphor existing in the predetermined region.
In this case, the irradiated portion of this phosphor emits fluorescence, but the amount of fluorescence gradually decreases thereafter. It is further assumed that the object to be inspected is slightly displaced forward along the predetermined direction after being irradiated with the excitation light, and the object to be inspected is slightly displaced from its original position. In this case, the irradiation site on the phosphor also slightly moves forward along the predetermined direction and reaches the detection region. The amount of fluorescence emitted from the irradiated portion reaching the detection region gradually decreases. Therefore, it should be observed that when the above-mentioned detection region is detected by an appropriate optical sensor or the like, fluorescence rapidly increases and then gradually decreases. On the other hand, when the object to be inspected is slightly displaced in the direction opposite to the above, the irradiation site on the phosphor moves to a region in which the predetermined region is slightly displaced rearward along the predetermined direction.
Therefore, the fluorescence detected in the detection area is rapidly reduced. If this is utilized, it is possible to detect that the phosphor has moved, for example, from the change in the fluorescence amount detected in the detection region, and further move by determining whether the fluorescence amount has sharply increased or decreased. The direction can be detected.

The same applies when the detection region corresponds to two regions obtained by slightly displacing the predetermined region both in the front and back in the predetermined direction. However, in this case, the fluorescence amounts from the two detection areas are monitored separately. Regarding the behavior of the fluorescent substance, the description in the case of using a single detection region is valid as it is. Therefore, when the fluorescent substance, that is, the object to be inspected is displaced from the original position, the fluorescence amounts detected in the two detection regions are complementary. It will increase or decrease. From this complementary increase / decrease in the amount of fluorescence, it is possible to detect the displacement of the phosphor in either the front or rear direction of the predetermined direction and the displacement direction thereof. For example, the occurrence and the direction of the displacement may be detected by obtaining the differential output of the fluorescence amount detected in the two detection areas.

The situation is slightly different when the detection region corresponds to two regions obtained by displacing the predetermined region in the front-back direction of the predetermined direction by a predetermined distance.

In this case, it is only after a predetermined time that the irradiated portion on the phosphor that is pulsed with the excitation light is detected by the fluorescence detecting means. Therefore, the displacement of the phosphor, that is, the object to be inspected cannot be detected during this predetermined time. However, the predetermined time (the time from the irradiation of the irradiated portion on the phosphor to the detection of the fluorescence by the excitation light pulse) and the predetermined distance between the predetermined area and the detection area, Based on, the average displacement speed of the fluorescent substance, that is, the object to be inspected can be detected.

For example, in the case where the excitation light is a pulse that is periodically generated, there is a problem as to at what time the irradiation site detected by the fluorescence detecting means is excited. This problem is solved by obtaining the peak value of the fluorescence amount detected by the fluorescence detecting means. That is, based on the decay curve of the fluorescence amount of the phosphor, the predicted value of the fluorescence amount of the irradiated portion on the phosphor at the predetermined time and the time obtained by adding or subtracting an integer multiple of the period of the excitation light pulse from this is obtained. By comparing the obtained predicted value with the peak value of the fluorescence amount detected by the fluorescence detecting means, it is possible to know at what time the irradiation site is excited.

Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is an embodiment of the first displacement detecting device according to the present invention.

The xenon lamp 12a, which is an excitation light source, generates pulsed excitation light based on a control signal from the control circuit 16.
The pulsed excitation light becomes the excitation light beam 22 through the condenser lens 12b and is incident on the fluorescent tape 28 attached to the object 50 to be inspected. The fluorescent tape 28 includes a phosphor portion 28a and a seal portion 28b. The phosphor in the predetermined region 24 irradiated with the excitation light beam 22 is excited to generate strong fluorescence.

On both sides of the xenon lamp 12a, a pair of photodetectors 14a and 14b are arranged as fluorescence detecting means. These photodetectors 14a and 14b are respectively the first and second photodetectors.
Control circuit for detecting the amount of fluorescence emitted from the detection regions 34a, 34b of
Output to 16. Here, the first detection area 34a corresponds to an area in which the predetermined area 24 has been moved by a predetermined distance d to either the front or the rear (the left side in the drawing) of the displacement direction of the object 50 to be inspected. The second detection area 34b corresponds to an area obtained by moving the predetermined area 24 by a predetermined distance d in the direction opposite to the first detection area 34a (right side in the drawing).

The control circuit 16 includes a lamp drive circuit, a peak hold circuit, a memory, a CPU, etc., and a pair of photodetectors 14a,
The moving speed and the like of the object 50 to be inspected is detected based on the detection output of 14b. Specifically, the lamp drive circuit is a xenon lamp.
12a generates periodic excitation light. The peak hold circuit detects the peak value of the fluorescence detection output from the pair of photodetectors 14a and 14b and the detection time thereof. The CPU identifies the time when the excitation light corresponding to this fluorescence is generated from the peak value of the fluorescence detection output and its detection time, calculates the time t from the irradiation of the excitation light to the fluorescence detection, and this time t and the predetermined distance The average moving speed of the object 50 to be inspected is given from d. Further, the moving speed of the test object 50 is calculated based on the fluorescence detection output from either one of the photodetectors 14a and 14b.
Therefore, the moving direction of the test object 50 can be detected by determining which photodetector the fluorescence detection output is obtained from. The memory stores data such as the decay curve of the fluorescence emission amount of the phosphor portion 28a.

The display unit 17 displays the object 50 to be inspected based on the calculation result of the CPU.
Displays the moving speed and the moving direction of.

 The operation of the displacement detector of FIG. 1 will be described below.

Consider a case where the object 50 to be inspected moves left and right on the drawing from the illustrated state. For example, after the pulse emission of the xenon lamp 12a, the test object 50 and the fluorescent table of FIG.
It is assumed that 28 has moved to the left on the drawing by a predetermined distance d or more. In this case, the portion of the fluorescent tape that was emitting fluorescence in the predetermined area 24 immediately after the pulsed light emission is the first detection area 34a.
Will pass through. Therefore, the amount of light detected by the photodetector 14a once increases and then decreases. The control circuit 16 is
From the peak value of the fluorescence detection output from the photodetector 14a,
The time t from the irradiation of the excitation light to the detection of fluorescence by the photodetector 14a is calculated. In addition, the predetermined area 24 and the detection area
Since the predetermined distance d with respect to 34a is given in advance, the average moving speed of the object 50 to be inspected can be obtained from this time t.

The above has described the case where the object 50 to be inspected in FIG. 1 moves to the left in the drawing, but the same applies when the object 50 to be inspected moves to the right in the drawing. In this case, the optical detector Since the fluorescence detection output is obtained from 14b, it is detected that the moving direction of the test object 50 is on the right side in the drawing.

The display unit 17 displays the moving speed and moving direction of the test object 50 based on the output of the control circuit 16. That is, the display is updated each time the fluorescence detection output is obtained from the photodetectors 14a and 14b.

FIG. 2 is an embodiment of the second displacement detecting device according to the present invention.

A support member 4 is mounted on the fixed base 11 so as to be movable in the left and right directions in the drawing. The movement of the support member is controlled by the screw 3 rotatably supported by the movement limits 21a and 21b and the servo motor 2 connected thereto.

Inside the support member 4, a xenon lamp 12a and a condenser lens 12b are fixed as an excitation light source. The pulsed excitation light from the xenon lamp 12a becomes the excitation light beam 22 through the condenser lens 12b and enters the fluorescent tape 28 attached to the object 50 to be inspected. The phosphor in the predetermined region 24 irradiated with the excitation light beam 22 is excited to generate strong fluorescence. A pair of photodetectors 14a and 14b are fixed as fluorescence detecting means on both sides of the xenon lamp 12a.
These photodetectors 14a and 14b can detect the fluorescence from the first and second detection regions 34a and 34b. Here, the first detection region 34a is a region that moves together with the support member 4, and corresponds to a region in which the predetermined region 24 is slightly moved to either one of the front side and the back side (left side in the drawing) in the movement direction of the support member. To do. In addition, the second detection area 34b is the support member 4
A region that moves together with the predetermined detection region 24 corresponds to a region that is slightly moved in the opposite direction of the first detection region 34a (on the right side in the drawing).

FIG. 3 shows a circuit configuration of the control circuit 16 etc. shown in FIG.

The xenon lamp 12a is driven by a lamp driving circuit 16b in the control circuit 16 and generates pulsed excitation light. This excitation light is applied to the fluorescent tape 28 via the condenser lens 12b shown in FIG. Also, the photodetectors 14a and 14b
Generates a voltage or current in response to the fluorescence from the fluorescent tape 28. The differential circuit 16a in the control circuit 16 detects the differential output of the current or voltage signal from the photodetectors 14a and 14b, and drives the servomotor 2. That is, when the amounts of light incident on both photodetectors become almost equal, the output terminal A
Is adjusted to be zero, and a voltage is generated at the output terminal A when the amounts of light incident on both photodetectors are unbalanced.

The servo motor 2 is driven by the positive or negative voltage generated at the output terminal A and moves the support member 4. In this case, the support member 4 is moved in the direction in which the imbalance of the outputs from both photodetectors is canceled.

The rotary encoder 18 attached to the servomotor 2 indirectly detects the movement amount of the support member 4 by monitoring the rotation of the servomotor 2. The output from the rotary encoder 18 is converted into the movement amount of the support member, that is, the movement amount of the object 50 to be inspected, and displayed on the display unit 17. In this case, the rotary encoder 18 serves as displacement detecting means.

The timing circuit 16c in the control circuit 16 controls the timing of the sequence operation. Here, the sequence operation is to cause the xenon lamp 12a to perform pulsed light emission, detect the fluorescence from the fluorescent tape 28 after that, and move the support member 4 in a predetermined direction in response to this, to move the support member 4
Is a series of operations until the positional relationship between the fluorescent tape 28 and the fluorescent tape 28 is returned to the original state. In other words, the timing circuit 16c first sends a signal to the lamp driving circuit 16b to cause the xenon lamp 12a to perform pulsed light emission for a predetermined time.
Next, the relay in the differential circuit 16a is controlled so that the servo motor 2 can be driven. If the light amounts detected by both photodetectors are balanced after a lapse of a predetermined time, the drive of the servomotor 2 is prohibited and the xenon lamp 12a
Pulse light emission for a predetermined time. Such a sequence operation is continuously repeated during the operation of the control circuit 16 or the displacement detecting device.

 The operation of the displacement detecting device shown in FIG. 2 will be described below.

Consider a case where the object 50 to be inspected moves left and right on the drawing from the illustrated state. With the movement of the object 50 to be inspected,
The fluorescent tape 28 also moves. If the relative position of the fluorescent tape 28 held in advance with respect to the support member 4 is called a reference position for convenience, the fluorescent tape 28 is displaced from the reference position.

It is assumed that the above phenomenon occurs after the pulse emission of the xenon lamp during the sequence operation. For example, if the object 50 and the fluorescent tape 28 in FIG. 2 move to the left in the drawing, the portion of the fluorescent tape that was emitting fluorescence in the predetermined area 24 immediately after the pulse emission is the first detection area. Move to the 34a side. Therefore, the amount of light detected by the photodetector 14a increases, and the amount of light detected by the photodetector 14b decreases. The outputs from these photodetectors are monitored by the differential circuit 16a, and the differential circuit 16a outputs the servomotor 2 based on the differential output.
To rotate.

Specifically, when the output difference from both photodetectors exceeds a predetermined value, it is determined that the fluorescent tape 28 has deviated from the reference position, and the fluorescent tape 28 deviates from the reference position depending on whether the output difference is positive or negative. You can determine the direction. Depending on this result,
The differential circuit 16a drives the servomotor 2 to move the support member 4 in the direction in which the fluorescent tape 28 is displaced (to the left in FIG. 2). When the output difference from both photodetectors falls below a predetermined value, the control circuit 16 stops the servomotor 2 and stops the rotation of the support member 4. As a result, the fluorescent tape 28 returns to the reference position. After that, even if the fluorescent tape 28 is displaced from the reference position again, as long as the differential circuit 16a is operating, the fluorescent tape 2
8 returns to the reference position.

When a predetermined time period has elapsed after the pulse emission of the xenon lamp 12a and the output difference from both photodetectors is less than or equal to a predetermined value, the object 50 and the fluorescent tape 28 have returned to the reference position with respect to the support member 4. Thus, this sequence operation ends. Therefore, again the xenon lamp 12a
Pulse light emission is performed, and a new sequence operation is started.

Here, it is desirable that the pulse emission time of the xenon lamp 12a be short. This is because movement of the fluorescent tape with respect to the support member 4 during pulsed light emission is not desirable in terms of measurement accuracy. Further, the time during which the servo motor 2 can be driven must not be longer than the fluorescent time of the fluorescent portion 28a of the fluorescent tape, but it cannot be shorter than the response time of the servo motor 2.

The above operation is performed when the object 50 and the fluorescent tape 28 move to the left with respect to the support member 4,
The same applies when the fluorescent tape 28 moves to the right, and the object 50 and the fluorescent tape 28 are maintained at the reference position. Here, if the movement amount of the support member 4 is monitored by the rotary encoder 18, the fluorescent tape 28, that is, the object
50 movements can be detected.

FIG. 4 is a first embodiment of the third displacement detecting device according to the present invention.

A cylindrical container 104 and a servomotor 2 which is a driving means are housed inside an outer box 1 which is a member to be detected for displacement. The servomotor 2 is fixed to a fixed point 3 provided at one end of the outer case 1. On the other hand, the container 104 is supported on the upper end of the outer box 1 by a bearing 6 or the like so as to be rotatable around the shaft 5. Further, the container 104 is connected to the servomotor 2 via the shaft 7, and its rotation is controlled by the servomotor 2.

Inside the container 104, as shown by an imaginary line, a cylindrical float 128 that is a movable member is housed. The float 128 is rotatably supported by bearings 9 and 10 about the same rotation axis as the rotation axis of the container 104. Also, the interior of the container 104 is filled with water and the float 128
And the buoyancy are almost equal. For this reason,
The load applied to the bearings 9 and 10 is reduced, and the float 128 itself maintains an accurate constant direction with respect to the external environment according to the inertial force. A phosphor is applied to the side surface of the float 128.

A xenon light source 12 for exciting the phosphor on the side surface of the float 128 is fixed to the outer side surface of the container 104. On the left and right of the xenon light source 12, a pair of photodetectors 114a, as a fluorescence detecting means for detecting the fluorescence emission amount of the fluorescent liquid 28,
114b is provided. The pulsed excitation light from the xenon light source 12 becomes an excitation light beam and enters the phosphor on the side surface of the float 128. Container 104 irradiated with excitation light beam
A fluorescent substance in a predetermined area therein is excited to generate strong fluorescence. Light detectors 114a, 1 on both sides of the xenon lamp 12a
Each of 14b can detect fluorescence from a detection region in which a predetermined region is slightly rotated on both sides around the container 104.

The configurations of the control circuit 16, the display unit 17, etc. are the same as those in FIG.

The photodetectors 114a and 114b generate a voltage or a current in response to the fluorescence from the phosphor on the side surface of the float 128 excited by the xenon light source 12. The control circuit 16 detects the differential output of the current or voltage signal from the photodetectors 114a and 114b, and drives the servomotor 2. That is, the rotation of the servomotor 2 is stopped when the amounts of light incident on both photodetectors become substantially equal. Further, when the amount of light incident on both photodetectors becomes unbalanced, the servomotor 2 is rotated in a direction to cancel the unbalance of the outputs from both photodetectors. A rotary encoder 18 attached to the servomotor 2 detects the rotation amount of the container 104. The output from the rotary encoder 18 is the angle indicator 17 as the rotation amount of the container.
Is displayed in.

 The operation of the displacement detector of FIG. 4 will be described below.

The illustrated displacement detection device is attached to an object on which the displacement detection device is to be mounted, for example, a vehicle or other device in which an angular displacement from vertical is to be detected.

Consider a case in which an object equipped with a displacement detection device rotates, and the displacement detection device rotates about an arbitrary axis parallel to its axis 5. In this case, since the rotation of the container 104 is controlled only by the servomotor 2, the container 104 does not rotate in the outer box 1, and the container 104 and the outer box 1 do not rotate.
The positional relationship of does not change. On the other hand, the float 128 maintains its original orientation or position due to its inertia. As a result, the float 128 rotates relative to the container 104 and the outer case 1. If the relative position of the float 128 held in advance with respect to the container is referred to as a reference position, the float 128 is displaced from the reference position.

It is assumed that the above phenomenon occurs after the pulse emission of the xenon lamp during the sequence operation. For example, if the float 128 shown in FIG. 4 rotates clockwise (actually, the outer box 1 and the container 104 rotate counterclockwise), fluorescence is emitted in the predetermined region 24 immediately after the pulse emission. The fluorescent substance on the float 128 that was generating the photodetector 114a
Move to the side. Therefore, the amount of light detected by the photodetector 114a increases, and the amount of light detected by the photodetector 114b decreases. The outputs from these photodetectors are monitored by the control circuit 16, and the control circuit 16 rotates the servomotor 2 based on the differential output.

Specifically, when the output difference from both photodetectors exceeds a predetermined value, it is determined that the float 128 has been rotationally displaced from the reference position, and the float 128 is determined by whether the output difference is positive or negative.
The direction of rotation from the reference position can be determined. In response to this result, the differential circuit drives the servomotor 2 and the container 104
Is rotated in the direction in which the float 128 is displaced (clockwise in FIG. 4). When the output difference from both photodetectors falls below a predetermined value, the control circuit 16 stops the servomotor 2 and the container 104
Stop rotating. As a result, the float 128 returns to the reference position. When a predetermined period of time has elapsed after the pulse emission of the xenon light source 12 and the output difference from both photodetectors is less than or equal to a predetermined value, the float 128 has returned to the reference position with respect to the container 104. The sequence operation ends. Therefore, the pulse emission of the xenon lamp 12 is performed again, and a new sequence operation is started. By the above operation, even if the float 128 deviates from the reference position in any direction by any amount, the float 128 returns to the reference position as long as the control circuit 16 is operating. Here, if the rotation encoder 18 monitors the rotation amount of the container 104, the rotation amount of the entire displacement detection device, that is, the angular displacement can be detected.

In this case, the positional relationship between the container 104 and the float 128 is
Although vibration is microscopically repeated near the reference position, it is kept constant macroscopically. Therefore, the container 104 is driven while always canceling the frictional resistance between the container 104 and the float 128 in the positive and negative directions, and the error caused by such frictional resistance can be minimized. You can

FIG. 5 is a diagram for explaining a second embodiment of the displacement detecting device of FIG. In this case, the displacement detecting device is configured to detect the rotational displacement in the horizontal plane.
Since many parts are common to the embodiment, those parts are omitted.

In the case of the displacement detection device shown, the container 104 is rotated by the servomotor 2 about a vertical axis of rotation 7. container
The float 128 accommodated in 104 is formed in a disk shape, and the side surface thereof is coated with the phosphor 128a. On the outer side surface of the container 104, a xenon light source 12 for irradiating the fluorescence pair 128a on the side surface of the float 8 with excitation light in a pulsed manner, and a pair of photodetectors 114a, 114b for detecting fluorescence from the phosphor 128a are provided. There is. The float 128 is suspended from the bearing 9 via a shaft 129. A magnetic needle 129a is fixed to the shaft 129, and the float 128 receives a force in a predetermined direction according to the magnetic field. Also, the container 104 is filled with water and the float 1
The specific gravity of water is set to be approximately equal to that of the magnetic needle 28 and the magnetic needle 129a.

The float 128, together with the magnetic needle 129a, is in the outside world and maintains a constant direction. The sequence of irradiation of excitation light by the xenon light source 12, detection of fluorescence by the photodetectors 114a and 114b, driving of the container 104 by the servomotor 2 and the like is the same as in the embodiment of FIG. A pair of photodetectors 114a, 114b
If the container 104 is rotated so that the amounts of light detected by and are integrated, the angular displacement of the displacement detection device can be easily detected.

The present invention is not limited to the above embodiment, but various modifications can be made.

For example, in the embodiment of FIGS. 2 and 4, the xenon lamp 12a may emit light continuously. in this case,
Since the fluorescent liquid is excited even during the operation of the servomotor, the rise of the fluorescence emission amount of the fluorescent liquid becomes a problem. When the amount of fluorescent light emission rises quickly, the fluorescent liquid is sufficiently excited before returning to the reference position, and the portion deviated from the light emitting portion begins to emit fluorescent light. As a result, the site that causes fluorescence emission gradually fluctuates, which also causes a measurement error. However, since such an error occurs due to the relative relationship between the rise time of the fluorescence emission amount and the response time of the servomotor or the like, the measurement error can be reduced by adjusting any time.

Further, in the embodiment of FIGS. 4 and 5, the shape of the container 104 does not have to be completely axisymmetric. Container 10 in operation
This is because the positional relationship between 4 and the float 128 does not change much. However, it is desirable that the shape of the container 104 is nearly axisymmetric. This is because if the shape of the container 10 is not axisymmetric, a minute turbulent flow will occur, which will cause an error.

Furthermore, in order to reduce the frictional resistance with the float 128, the inside of the container 104 may be coated with Teflon or the like.

Further, a buffer made of a hollow tube may be provided inside the side surface of the container 104. Since this buffer expands and contracts in accordance with the pressure of the liquid in the container, it can absorb the volume change of water due to the temperature change and can prevent the generation of bubbles.

Furthermore, the container 104 may be a vacuum container, and the pressure inside may be reduced. It is possible to make the frictional resistance from the fluid in the container almost negligible.

Further, as the excitation light source used in the embodiments of FIGS. 2, 4 and 5, use a light source such as LED or LD as long as it generates light corresponding to the excitation wavelength of the phosphor. You can

Furthermore, in the case of this embodiment shown in FIGS. 2 and 4, a pair of photodetectors is used as the fluorescence detecting means, but a single photodetector may be used. In this case, one of the photodetectors 14b shown in FIGS. 2 and 4 may be omitted. In this case, the photodetector 34 (a is allowed to partially detect the fluorescence emission from the predetermined region 24. When the fluorescence emission amount detected by the photodetector 34a decreases exponentially according to the decay curve of the afterglow. Therefore, it is considered that the position of the fluorescent liquid is at the reference position.Therefore, when the fluorescence emission amount detected by the photodetector does not decrease exponentially according to the above-mentioned decrease curve, that is, when the fluorescence emission amount sharply increases or decreases sharply. It is considered that the fluorescent liquid has deviated from the reference position, and the direction in which the fluorescence emission amount deviates from the reference position is determined by whether the detected fluorescence emission amount sharply increases or decreases.

Further, in the embodiment of FIGS. 4 and 5, the rotation of the container 104 with respect to the outer box 1 may be measured by a resistor. For example, there is a method of increasing or decreasing the variable resistance value of the resistor according to the rotation amount and direction of the servo motor 2. By monitoring the resistance value of the resistor, the drive amount and direction of the servo motor 2 can be detected, and the rotation amount of the container 104 can be measured.

〔The invention's effect〕

As described above, according to the first, second, and third displacement detection devices, it is possible to provide a displacement detection device that has an extremely simple structure and is small and lightweight.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a first displacement detection device according to the present invention, and FIG. 2 is a diagram showing a configuration of an embodiment of a second displacement detection device according to the present invention. FIG. 3 is a circuit diagram of the displacement detecting device of FIG. 2, FIG. 4 is a diagram showing a configuration of a first embodiment of a third displacement detecting device according to the present invention, and FIG. It is the figure which showed the structure of 2nd Example of the displacement detection apparatus of 3. 4 ... Support member, 104 ... Container, 12 ... Excitation light source, 14a,
14b, 114a, 114b ... fluorescence detecting means, 2 ... driving means, 1
6 ... Displacement detecting means, 18 ... Displacement amount detecting means, 28 ... Phosphor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Kobayashi 1 1126, Nomachi, Hamamatsu City, Shizuoka Prefecture 1126 Hamamatsu Photonics Co., Ltd. Within

Claims (3)

(57) [Claims] 1. An excitation light source for irradiating a phosphor existing in a predetermined region, the displacement of which is to be detected, with excitation light, and a detection corresponding to a region obtained by displacing the predetermined region forward or backward or both in a predetermined direction. Fluorescence detection means for detecting the fluorescence from the fluorescent material present in the region, based on the output of the fluorescence detection means, that the fluorescent material is displaced, the displacement direction before and after along the predetermined direction Displacement detecting means for detecting whether or not the direction of the displacement is detected. 2. A support member capable of reciprocating along a predetermined direction, and excitation light for a phosphor which is provided on the support member side and whose displacement existing in a predetermined region with respect to the support member is to be detected. And an excitation light source for irradiating the fluorescent material, which is provided on the side of the supporting member, and emits fluorescence from the phosphor existing in a detection region corresponding to a region obtained by displacing the predetermined region to one or both of the front and rear in the predetermined direction. Fluorescence detection means for detecting, based on the output of the fluorescence detection means, that the phosphor is displaced with respect to the support member, the displacement direction is either the front or back direction along the predetermined direction, Displacement detecting means for detecting the displacement of the fluorescent material, drive means for displacing the supporting member in the displacement direction of the fluorescent material when the displacement detecting means detects displacement of the fluorescent material, and detecting the displacement amount of the supporting member. Displacement detecting device, characterized in that it comprises a displacement detecting means. 3. A movable member, which is rotatably supported around a predetermined rotation shaft provided on a displacement detection member whose displacement is to be detected, and which has a phosphor on the surface, and which houses the movable member. In addition, a container that is rotatable around the predetermined rotation axis, and an excitation light source that is provided on the container side and irradiates the phosphor existing in a predetermined region in the container with excitation light, and the container Fluorescence detection means that is provided on the side and that detects fluorescence from the phosphor existing in a detection region corresponding to a region in which the predetermined region is displaced to one or both around the predetermined rotation axis, and the fluorescence Displacement detecting means for detecting, based on the output of the detecting means, that the movable member is rotationally displaced with respect to the container, and which displacement direction is around the predetermined rotation axis. When the displacement detection means detects the rotational displacement of the movable member, the drive means for rotating the container in the displacement direction of the movable member, and the displacement amount for detecting the rotational displacement amount of the container with respect to the displacement detection member. A displacement detection device comprising: a detection unit.