JPH06265331A - Optical displacement detector - Google Patents

Abstract

PURPOSE:To obtain an optical displacement detector which can accurately detect a rotary angle irrespective of an extent of an angle detecting range, facilitates both shaft structures, and has a small size and a long life of a light source. CONSTITUTION:The optical displacement detector comprises a rotary shaft 1 engaged with an element to be measured and as a part of the element to be measured, a rotary plate 40 rotating integrally with the shaft 1 and having a side periphery as an optical diffusion surface and a radius becoming different in response to rotation of the shaft 1, a light source 3 for irradiating the diffusion surface of the plate 40 with a light, a condenser lens 45 for condensing a reflected light from the diffusing surface of the plate 40, and an optical position detecting element 5 disposed substantially at the condensing position of the lens 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical displacement detecting device for detecting the displacement of an object in a non-contact manner, and more particularly to an optical position detecting type optical displacement detecting device using, for example, an optical position detecting element as a light receiving element. It is a thing.

[0002]

2. Description of the Related Art In recent years, in order to detect the rotation angle of an object with high durability and reliability, a rotation for detecting the rotation angle of the object while being in electrical contact with the object using a variable resistor. Radiation from the object to be measured instead of the angle detection device,
Alternatively, a non-contact type in which the light reflected and transmitted by the object to be measured is received by an optical position detection element equipped with a resistance layer and the rotation angle of the object to be measured is detected according to the light receiving position at this optical position detection element An optical displacement detection device is used. As such an optical displacement detection device, for example, devices shown in FIGS. 12 and 13 and 14 have been proposed. 12 and 13 are configuration diagrams showing a conventional optical displacement detecting device disclosed in Japanese Patent Laid-Open No. 61-246620 and cross-sectional views showing an optical position detecting element, and FIG.
FIG. 14B is a configuration diagram of an optical system of a conventional optical displacement detection device disclosed in Japanese Patent Publication No. 124821.
It is a top view of the optical system of the conventional optical displacement detection apparatus shown in A.

First, referring to FIG. 12, Japanese Patent Laid-Open No. 61-24
A conventional optical displacement detection device disclosed in Japanese Patent No. 6620 will be described. In the figure, reference numeral 1 denotes a rotary shaft connected to a rotary object as an object to be measured (not shown), and 2 denotes a rotary slit plate which is inserted through and attached to the rotary shaft 1 and which rotates about the rotary shaft 1 as a rotary shaft 2a.
Is a spiral slit formed on the rotary slit plate 2 and its radius changes in accordance with the rotation of the rotary slit plate 2, 3 is a light source, and 4 is within the range of the optical axis of the light source 3 and is rotated. Fixed slit plates 4a arranged in parallel with the slit plate 2 are fixed slits formed in the fixed slit plate 4 spirally and formed in the rotary slit plate 2 so as to intersect the spiral slits 2a. Receives the light emitted from the light source 3 and supplied through the spiral slit 2a of the rotary slit plate 2 and the fixed slit 4a of the fixed slit plate 4, so that its light receiving axis has a rotary axis.
An optical position detecting element arranged in the radial direction of
Reference numerals 8 and 8 denote detection electrodes for outputting a detection current of the optical position detection element 5, and reference numeral 7 denotes a bias voltage application electrode for supplying a bias voltage from a power supply circuit (not shown) to the optical position detection element 5.

Next, the structure of the detection circuit 8A will be described. 9 is connected to the detection electrode of the optical position detection element 5,
An input terminal to which the detection current I1 from the optical position detection element 5 is supplied. The input terminal 9 is connected to the inverting input terminal (-) of the operational amplifier circuit 13 via the resistor R1 of the current / voltage conversion circuit 12. At the same time, it is connected to one end of the resistor R3 of the adding circuit 14 via the resistors R1 and R2. The inverting input terminal (-) of the operational amplifier circuit 13 of the current / voltage conversion circuit 12 is connected to its output terminal via the resistor R2, and the non-inverting input terminal (+) of the operational amplifier circuit 13 is grounded. There is. Reference numeral 10 is connected to the bias voltage applying electrode of the optical position detecting element 5, and the bias voltage applying electrode of the optical position detecting element 5 is connected to the current / voltage converting circuit 12.
This is an input terminal for setting the ground potential of and is grounded.
That is, the current / voltage conversion circuit 12 converts the detection current I1 from the optical position detection element 5 into the voltage V1.

The other end of the resistor R3 of the adder circuit 14 is connected to one end of a resistor R6 of the comparison and integration circuit 16 via a resistor R5, and is also connected to the inverting input terminal (-) of the operational amplifier circuit 15. Further, the inverting input terminal (-) is connected to the output terminal through the resistor R5, and further the resistor R4
Is connected to the output terminal of the operational amplifier circuit 20 of the current-voltage conversion circuit 19 which will be described later, and the non-inverting input terminal (+) of the operational amplifier circuit 15 is grounded. The other end of the resistor R6 of the comparison and integration circuit 16 is connected to the input terminal of the light emitting circuit 24 described later via the capacitor C1 and also to the inverting input terminal (-) of the operational amplification circuit 17, and this operational amplification circuit is connected. The non-inverting input terminal (+) of 17 is grounded via the reference power supply 18. That is, the comparison and integration circuit 16 compares the voltage supplied to the inverting input terminal (−) with the voltage supplied to the non-inverting input terminal (+), and controls the light emitting circuit 24 based on the result. The light emitting circuit 24 drives the light source 3 via the control terminal 25.

Reference numeral 11 is a detection electrode 8 of the optical position detection element 5.
Is an input terminal to which the detection current I2 from the optical position detecting element 5 is supplied. The input terminal 11 is connected to the inverting input terminal (-) of the operational amplifier circuit 20 via the resistor R7 of the current / voltage conversion circuit 12. ), And is also connected to one end of a resistor R9 of the amplifier circuit 21 via resistors R7 and R8. The operational amplifier circuit 20 of the current / voltage conversion circuit 19
The inverting input terminal (-) is connected to its output terminal via the resistor R8, and the non-inverting input terminal (+) of this operational amplifier circuit 20 is grounded. That is, the current / voltage conversion circuit 19 converts the detection current I2 from the optical position detection element 5 into the voltage V2.

The other end of the resistor R9 of the amplifier circuit 21 is connected to the output terminal 23 for the displacement detection output V _θ via the resistor R10 and to the inverting input terminal (−) of the operational amplifier circuit 22. The non-inverting input terminal (+) of the operational amplifier circuit 15 is grounded. Next, with reference to FIG. 13, the configuration of the optical position detecting element 5 shown in FIG. 12 will be described in more detail. As shown in this figure, in the optical position detecting element 5, the photoelectric conversion layer 5a is sandwiched between the transparent resistance layer 5b and the bias voltage applying electrode 7, and the detection electrodes 6 are provided at both ends of the transparent resistance layer 5b.
And 8 are provided respectively. Also,
From the detection electrodes 6 and 8, leads 5c and 5 respectively.
d is connected, the lead 5e is connected to the bias voltage applying electrode 10, and a predetermined bias voltage (here, the case of grounding is shown) is supplied through the output terminal 10 of the detection circuit 8 shown in FIG. .

Next, the operation will be described. Light emitting circuit 24
When light is emitted from the light source 3 in the direction of the rotary slit plate 2 by driving, the emitted light is projected onto the projection range on the rotary slit plate 2, and among the projected light, the rotary slit plate 2
Only the light passing through the crossing range of the spiral slit 2a of the fixed slit 4a of the fixed slit plate 4
Is incident on the light receiving surface of. When a light beam is incident on the light receiving surface of the light position detection element 5, the incident light beam passes through the transparent resistance layer 5b and is photoelectrically converted by the photoelectric conversion layer 5a, and the detected currents I1 and I are detected.
2 flows through the transparent resistance layer 5b toward the detection electrodes 6 and 8 at both ends thereof. At this time, since the magnitudes of the detection currents I and I2 differ depending on the distances to the detection electrodes 6 and 8,
The light receiving position X from the detection electrode 6 is the detection currents I1 and I2.
Therefore, it can be expressed as follows.

X = L × I2 / (I1 + I2) (1)

However, in the above formula (1), L is the light receiving length of the light position detecting element 5. Therefore, in the detection circuit 8A of FIG. 12, the detection currents I1 and I2 are converted into the voltages V1 and V2 by the current / voltage conversion circuits 12 and 19, respectively, and the addition output (V1 + V2) is obtained by the addition circuit 14 and this addition output ( (V1 + V2) becomes a predetermined value, the light emission intensity of the light source 3 is controlled by the comparison and integration circuit 16 through the light emission circuit 24, and the voltage V2 corresponding to one current I2 is amplified by the amplification circuit 21.
Then, by applying a predetermined gain and outputting, a rotation angle output V _θ corresponding to the light receiving position X of the light position detecting element 5 and corresponding to the rotation angle θ of the rotary slit plate 2 is obtained. That is,
When the rotary slit plate 2 rotates together with the rotary shaft 1, the intersecting range of the spiral slit 2a of the rotary slit plate 2 and the fixed slit 4a of the fixed slit plate 4 sequentially moves in the radial direction of the rotary slit plate 2 to detect the optical position detecting element. Since the light receiving position on 5 moves in the radial direction of the rotary slit plate 2 and changes according to the rotation angle of the rotary slit plate 2, the light position detecting element 5
The light receiving position on the above is determined by the detection electrodes 6 and 8 of the light position detecting element 5.
The output current ratio of the output current from the detection circuit 8 shown in FIG.
By detecting at A, the rotation angle of the rotary shaft 1 can be detected. Therefore, it is possible to detect the rotation angle of the measured object to which the rotation shaft 1 is connected.

Next, referring to FIG. 14, Japanese Patent Laid-Open No. 61-12
The conventional optical displacement detection device disclosed in Japanese Patent No. 4821 will be described. In FIG. 14, parts corresponding to those in FIGS. 12 and 13 are designated by the same reference numerals, and detailed description thereof will be omitted. In the figure, 30 is a case whose shape is cylindrical as shown in FIG. 14A, 31 is a rotary bearing for supporting the rotary shaft 1, and 32 is a case 9.
An annular element support substrate attached to the inside of the case 3 on the rotary bearing 31 side of the case 3, 33 is an element support on the inside of the case 30 and on an annular element support substrate 32 attached to the inside of the case 30. It is an annular optical position detection element that is mounted similarly to the substrate 32. The light source 34 is attached to the hole of the case 30 such that the light emitting direction is directed to the inside of the case 30 and the optical axis coincides with the rotation axis 1.
It is a rotary slit member for making the light from the light incident on the optical position detecting element 33. The rotary slit member 34 has a light-transmitting body 34a in which a light-reflecting layer 34d is formed.
The translucent body 34a includes a light source side slit 34b for passing light from the light source 3 and a light source side slit 3b.
4b for reflecting the light incident from 4b.
c, a second reflecting surface 34e for reflecting the light reflected by the first reflecting surface 34c, and a light receiving side slit 34f for making the light reflected by the second reflecting surface 34e incident on the light position detecting element 33. Has been done.

Next, the operation will be described. When light is emitted from the light source 3, a part of the emitted light enters the light transmitting body 34a through the light source side slit 34b of the rotary slit member 34. This light is reflected by the first reflecting surface 34 formed inside the translucent body 34a, as indicated by the solid arrow in FIG. 14A.
The light is reflected by the light reflecting layer 34d of c, passes through the light transmitting body 34a, and reaches the second reflecting surface 34e.
The light position detecting element 33 is reflected from the light receiving side slit 34f after being reflected by the light reflecting layer of FIG.
Is incident on the light receiving surface of. In this case, the rotary slit member 34
Since the projection range (spot) 35 of light on the optical position detecting element 33 changes with the rotation of the optical position detecting element 33,
The rotation angle of the rotary shaft 1 is determined by detecting the output current ratio of the output currents from the output terminals 6 and 8 connected to the detection electrodes of the light position detection element 33 at the light receiving position above. Can be detected. Therefore, it is possible to detect the rotation angle of the measured object to which the rotation shaft 1 is connected.

[0013]

Since the conventional optical displacement detection device is constructed as described above, the optical displacement detection device described with reference to FIGS.
Since the change in the rotation angle is detected at the light receiving position in the radial direction of the light position detecting element 5 in a one-to-one manner with respect to the change in the slit position, the spiral slit 2a and the fixed slit 4a.
If it is attempted to improve the detection accuracy without making it fine, the detection distance must be extended in the radial direction, the diameter of the device becomes large, and a predetermined spot diameter is obtained from the light source 3 through the slit. Therefore, it is necessary to increase the light emission amount of the light source 3, and there is a problem that the life of the light source 3 is shortened accordingly.

Further, in the optical displacement detection device described with reference to FIG. 14, the diameter of the spot on the light receiving surface of the light position detection element 33 is reduced by the presence of obliquely transmitted light passing through the light receiving side slit 34f. Since the diameter of the projection area (spot) 35 of the light shown in 14b is larger than the diameter of the light receiving side slit 34f, the light receiving length of the light position detecting element 33 cannot be effectively used, and the detection angle range is narrow. In this case, it is not suitable for measurement when the detection angle range is close to 2π, and there is a problem that the biaxial configuration cannot be adopted because the light source 3 is arranged coaxially with the rotating shaft 1. .

The present invention has been made in order to solve such a problem, and it is possible to detect the displacement of the object to be measured with high accuracy regardless of the size of the angle detection range, and it is possible to easily realize the double axis. It is an object of the present invention to obtain an optical displacement detection device that is small in size and can extend the life of a light source.

[0016]

An optical displacement detecting device according to a first aspect of the present invention includes a rotary shaft which is attached to a part to be measured or is a part thereof, and a rotary shaft which is attached to the rotary shaft and integrally rotates. Then, with a rotating plate whose side peripheral portion is an optical diffusion surface,
A light source that irradiates the optical diffusion surface of the rotating plate with light, a condensing optical system that condenses the reflected light from the optical diffusion surface of the rotating plate, and the light condensing optical system is arranged at a substantially condensing position. And a rotating plate is formed such that the distance between the condensing optical system and the light reflecting position of the side peripheral portion is different according to the rotation angle of the rotating shaft, The displacement of the object to be measured is detected based on the light incident position on the light position detecting element.

According to a second aspect of the present invention, there is provided an optical displacement detecting device, which is attached to the object to be measured or is a part thereof, and a rotating shaft which is attached to the rotating shaft and integrally rotates to form a side peripheral portion. A rotating plate having an optical diffusing surface, a light source for irradiating the optical diffusing surface of the rotating plate with light, and a condensing optical system for condensing the reflected light from the optical diffusing surface of the rotating plate,
The rotating plate is provided with a light position detecting element arranged at a substantially condensing position of the condensing optical system, and the rotating plate has a distance between the condensing optical system and a light reflecting position of the side peripheral portion is a rotation angle of the rotating shaft. The relationship between the rotation angle of the rotary shaft and the radius of the rotary plate is determined according to the rotation angle of the measured object, and the relationship is determined based on the light incident position on the light position detection element. In addition, the object of the object to be measured is detected.

An optical displacement detecting device according to a third aspect of the present invention is a reciprocating shaft that is attached to or a part of an object to be measured, and is attached to the reciprocating shaft to move integrally with the side portion. A reciprocating plate that is an optical diffusing surface, a light source that irradiates the optical diffusing surface of the reciprocating plate with light, and a condensing optical system that condenses the reflected light from the optical diffusing surface of the reciprocating plate,
The reciprocating plate is provided with a light position detecting element disposed at a substantially condensing position of the condensing optical system, and a distance between the condensing optical system and a light reflecting position of the side portion of the reciprocating plate depends on a stroke of the reciprocating shaft. Differently formed, the displacement of the object to be measured is detected based on the light incident position on the light position detecting element.

According to a fourth aspect of the present invention, there is provided an optical displacement detecting device, wherein a reciprocating shaft which is attached to a part to be measured or is a part of the reciprocating shaft and which is attached to the reciprocating shaft and moves integrally with the reciprocating shaft. A reciprocating plate that is an optical diffusing surface, a light source that irradiates the optical diffusing surface of the reciprocating plate with light, and a condensing optical system that condenses the reflected light from the optical diffusing surface of the reciprocating plate,
The reciprocating plate is provided with a light position detecting element disposed at a substantially condensing position of the condensing optical system, and a distance between the condensing optical system and a light reflecting position of the side portion of the reciprocating plate depends on a stroke of the reciprocating shaft. Differently formed, the relationship between the stroke displacement of the reciprocating shaft and the side portion of the reciprocating plate is determined according to the stroke of the object to be measured, and the relationship is determined based on the light incident position on the light position detecting element. The displacement of the object to be measured is detected.

[0020]

According to the first aspect of the present invention, the light incident position on the light position detecting element arranged at the substantially condensing position of the condensing optical system for condensing the reflected light from the optical diffusion surface of the rotating plate The rotation angle of the object to be measured is detected based on the principle of triangulation. As a result, the rotation angle can be accurately detected regardless of the size of the angle detection range, and a device having a simple biaxial configuration and a small light source with a long life can be obtained.

According to the second aspect of the present invention, the relationship between the rotation angle of the rotary shaft and the radius of the rotary plate is obtained as a linear output according to the rotation angle of the object to be measured based on the principle of triangulation. The radius change of the rotating plate is determined so that This allows
A rotation angle can be accurately detected regardless of the size of the angle detection range, a biaxial configuration is easy, and a small and inexpensive light source having a long life can be obtained.

According to the third aspect of the present invention, the reflected light from the optical diffusing surface of the reciprocating plate, which is formed so that the distance from the reciprocating center of the reciprocating plate to the side portion varies depending on the stroke of the reciprocating shaft, is used as a condenser optics. Based on the principle of triangulation, the stroke displacement of the object to be measured is detected by the light incident position on the light position detecting element which is focused by the system and is arranged at the substantially focusing position of this focusing optical system. As a result, the stroke displacement can be accurately detected regardless of the size of the stroke detection range, and a device having a simple two-axis configuration and a small size and a long light source can be obtained.

According to the fourth aspect of the present invention, the linear relationship between the stroke displacement of the reciprocating shaft and the side of the reciprocating plate is linearly output according to the stroke of the object to be measured based on the principle of triangulation. The change in the side portion of the reciprocating plate is determined so as to be obtained. As a result, a stroke displacement can be accurately detected regardless of the size of the stroke detection range, the two-axis configuration is easy, and the device is small and inexpensive, and the light source has a long life.

[0024]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an optical system of an optical displacement detecting device according to an embodiment of the present invention.
The same reference numerals are given to the portions corresponding to 4, and the detailed description thereof will be omitted. In the figure, the rotary bearings 31 are attached to both ends of the case 30, and the rotary shaft 1 is attached by the two rotary bearings 31.
To support both axes. Reference numeral 40 denotes a rotary plate whose outer peripheral surface (side peripheral portion) is an optical diffusion surface.
0 is fixed to the rotary shaft 1 so that it rotates in conjunction with the rotary shaft 1.

Reference numeral 41 is an element supporting substrate, 42 is a diaphragm member, 4
3 is a collimator lens, 44 is a support member, and 45 is a condenser lens for condensing the light reflected from the optical diffusion surface of the rotary plate 40 on the optical position detection element 5. As shown in this figure, the element support substrate 45 is attached to a ceiling portion inside the case 30, a light source 3 such as an LED is attached to the element supporting substrate 45 so that the light emitting direction thereof is the direction of the rotation axis 1, and the diaphragm member 42 is an optical axis with the light source 3. Are fixed to the outer peripheral surface of the light source 3 so as to match with each other, and the supporting member 42 supports the collimator lens 43.
Is fixed to the outer peripheral surface of the optical position detecting element 5 so that the condenser lens 45 is supported by the supporting member 44. The rotation angle of the object to be measured can be detected with high accuracy regardless of the size of the rotation angle detection range, and the optical system can be compactly formed on one side of the case 30, so that it is possible to easily achieve dual axes. In addition, the device can be downsized.

Here, if the collimator lens 43 and the condenser lens 45 are made of plastic molded products made of optical plastic such as polymethylmethacrylate (PMMA) and polycarbonate (PC), the cost can be reduced. . Next, the operation will be described. In FIG. 1B, the light emitted from the light source 3 is transmitted through the collimator lens 43 and the diaphragm 42, becomes a parallel light flux of a predetermined diameter, enters the outer peripheral surface of the rotating plate 40, and is reflected by the optical diffusion surface on the outer peripheral surface. It Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. When the rotary shaft 1 rotates here, the focused spot light moves on the optical position detecting element 5. Therefore, the light incident position of the light position detection element 5 is the rotation plate 40, that is,
It becomes equal to the rotation angle of the rotary shaft 1, and the detection currents I1 and I2 are obtained from the detection electrodes of the optical position detection element 5 as in the conventional device described with reference to FIGS. If I2 is detected by the same detection circuit as in the conventional device, the rotation angle V _θ corresponding to the light incident position X can be obtained.

This example is based on the principle of triangulation, and by increasing the distance change rate between the reflecting surface and the light receiving portion, it is possible to effectively detect from one end of the light receiving surface to the other. Can detect with high accuracy even if the width is narrow, and can detect the maximum detection angle range to about 2π, and even with the light position detecting element of the light receiving surface having a small diameter, the device can be made small and small in diameter. A double shaft configuration can be used. Further, since the light source 3 directly irradiates the light source diffusion surface without interposing a slit, the amount of light emission can be reduced correspondingly, and the life can be extended.

Example 2. In the above embodiment, the light source 3
The case has been described in which the light from the above is applied to the optical diffusion surface of the rotating plate 40 via the diaphragm member 42 and the collimator lens 43. However, as shown in FIG.
Alternatively, the prism 47 having a reflection surface of 45 degrees with respect to the optical diffusion surface of the rotating plate 40 may be supported and fixed. In this case, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is deflected by 90 degrees by the prism 47,
The deflected light is applied to the optical diffusion surface of the rotating plate 40, and the light reflected by the optical diffusion surface of the rotating plate 40 is deflected again by 90 degrees by the prism 47, and the deflected light is condensed by the condenser lens 45.
Is incident on the light receiving surface of the optical position detecting element 5. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended. Furthermore, if a metal such as Al is deposited on the reflecting surface to form a reflecting mirror, the reflectance can be improved.

Example 3. Further, as shown in FIG. 2B, a flat reflecting mirror 48 having an angle of 45 degrees with respect to the optical diffusion surface of the rotating plate 40 may be supported and fixed to the case 30.
In this case, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is deflected by 90 degrees by the flat reflecting plate 48, and the deflected light is irradiated on the optical diffusion surface of the rotating plate 40.
Light reflected by the optical diffusion surface of the rotating plate 40 is reflected by the flat reflecting plate 48.
Is again deflected by 90 degrees, and the deflected light is incident on the light receiving surface of the optical position detecting element 5 by the condenser lens 45. Also in this case, similarly to the above, even if the detection angle range is narrow, it is possible to detect with high accuracy, and the maximum detection angle range is approximately
Since it can be set to π, and even the light position detection element of the light receiving surface having a small diameter can be detected with high accuracy, the device can be made small in size and small in size, and can have a biaxial structure, thus extending the life of the light source. be able to. Furthermore, if a metal such as Al is deposited on the reflecting surface to form a reflecting mirror, the reflectance can be improved.

Example 4. Further, as shown in FIG. 2C, a mirror surface 30a having an angle of 45 degrees with respect to the optical diffusion surface of the rotary plate 40 may be formed on the surface of the case 30 by plating, vapor deposition or the like. In this case, the collimator lens 43 and the diaphragm member 42
The light from the light source 3 that has passed through is reflected by the mirror surface 30a by 90 degrees, and the optical diffusion surface of the rotating plate 40 is irradiated with the deflected light.
The light reflected by the optical diffusion surface of the rotating plate 40 is again deflected by 90 degrees on the mirror surface 30a, and the deflected light is condensed by the condenser lens 4
The light is incident on the light receiving surface of the optical position detecting element 5 by the light source 5. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended. Furthermore, if a metal such as Al is deposited on the reflecting surface to form a reflecting mirror, the reflectance can be improved.

Example 5. In the above embodiment, the light source 3
The case has been described in which the light from the above is applied to the optical diffusion surface of the rotating plate 40 via the diaphragm member 42 and the collimator lens 43. However, as shown in FIG.
Further, a trapezoidal prism 49 having two reflecting surfaces forming a narrow angle of 90 degrees with respect to the optical diffusion surface of the rotating plate 40 may be supported and fixed. In this case, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is twice deflected by the trapezoidal prism 49 by 90 degrees, that is, 180 degrees, and the optical diffusion surface of the rotary plate 40 is irradiated with the deflected light. ,
The light reflected by the optical diffusion surface of the rotary plate 40 is deflected twice by the trapezoidal prism 49 by 90 degrees, that is, by 180 degrees, and the deflected light is reflected by the condenser lens 45 on the light receiving surface of the optical position detecting element 5. It is incident.

In this case as well, similar to the above, even if the detection angle range is narrow, it is possible to detect with high accuracy, and the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately measured. Since it can be detected, the device can be made small in diameter and small in size, and can have a biaxial structure, so that the life of the light source can be extended. Furthermore, if a metal such as Al is deposited on the reflecting surface to form a reflecting mirror, the reflectance can be improved.

Example 6. Further, as shown in FIG. 3B, two flat reflecting mirrors 50 and 51 forming a narrow angle of 90 degrees with respect to the optical diffusion surface of the rotating plate 40 may be supported and fixed to the case 30. In this case, the light from the light source 3 which has passed through the collimator lens 43 and the diaphragm member 42 is reflected by the plane reflecting mirrors 51 and 5.
At 0, it is sequentially deflected by 90 degrees, for a total of 180 degrees.
The deflected light is applied to the optical diffusing surface of the rotating plate 40, and the light reflected by the optical diffusing surface of the rotary plate 40 is sequentially reflected by the plane reflecting mirrors 50 and 51.
The light is deflected by 0 ° for a total of 180 °, and the deflected light is incident on the light receiving surface of the optical position detection element 5 by the condenser lens 45. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended. Furthermore, if a metal such as Al is deposited on the reflecting surface to form a reflecting mirror, the reflectance can be improved.

Example 7. Further, as shown in FIG. 3C, two mirror surfaces 30a and 30b may be formed on the surface of the case 30 by plating, vapor deposition, or the like, forming a narrow angle of 90 degrees with respect to the optical diffusion surface of the rotating plate 40. . In this case, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is sequentially reflected on the mirror surfaces 30b and 30a by 90 degrees, for a total of 18 degrees.
The deflected light is deflected by 0 degrees, and the deflected light is applied to the optical diffusion surface of the rotating plate 40. The light reflected by the optical diffusion surface of the rotating plate 40 is deflected by 90 degrees in order by 90 degrees in total for a total of 180 degrees. The light is incident on the light receiving surface of the optical position detecting element 5 by the condenser lens 45. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended.
Furthermore, if a metal such as Al is deposited on the reflecting surface to form a reflecting mirror, the reflectance can be improved.

Example 8. FIG. 4 is a structural schematic diagram showing a configuration of an optical system of an optical displacement detecting device according to still another embodiment of the present invention. 4, parts corresponding to those in FIGS. 1 to 3 are designated by the same reference numerals, and detailed description thereof will be omitted. In this example, the inner peripheral portion 53a of the rotary plate 53 is an optical diffusion surface, and in this case, the collimator lens 43 is used.
And the light from the light source 3 that has passed through the diaphragm member 42
Is reflected by the optical diffusion surface formed on the inner peripheral portion 53a of 3,
The light reflected by this optical diffusion surface is the condenser lens 45.
Is incident on the light receiving surface of the optical position detecting element 5.

Also in this case, similarly to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, and the maximum detection angle range can be set to approximately 2π, and even if the light position detecting element of the light receiving surface having a smaller diameter is used, it is possible to accurately detect it. Since it can be detected, the device can be made small in diameter and small in size, and can have a biaxial structure, so that the life of the light source can be extended. Further, according to this configuration, since the light emitting means including the light source 3 and the light receiving means including the light position detecting element 5 are arranged in the vicinity of the rotation axis 1,
The device can be made smaller. In this example also, the optical diameter is 90 degrees, as in Examples 2 to 7 above.
An 80 degree deflection means can be used.

Example 9. FIG. 5 is a structural schematic diagram showing a configuration of an optical system of an optical displacement detecting device according to still another embodiment of the present invention. 5, parts corresponding to those in FIGS. 1 to 4 are designated by the same reference numerals, and detailed description thereof will be omitted. In this example, the radii of the inner peripheral portion 54a and the outer peripheral portion 54b of the rotary plate 54 are changed according to the rotation angle, and optical diffusion surfaces are formed on the surfaces of the inner peripheral portion 54a and the outer peripheral portion 54b, respectively. A unit including the light source 3, the light position detection element 5, the collimator lens 43, the supporting members 42 and 44, and the condenser lens 45 is provided inside and outside the rotating plate 53, respectively.

In this case, the light from the light source 3 which has passed through the collimator lens 43 and the diaphragm member 42 is reflected by the optical diffusion surface formed on the inner peripheral portion 54a of the rotating plate 54, and the light reflected by this optical diffusion surface is The light is incident on the light receiving surface of the optical position detecting element 5 by the condenser lens 45. Similarly, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is reflected by the optical diffusion surface formed on the outer peripheral portion 54 a of the rotating plate 54, and the light reflected by this optical diffusion surface is converted by the condenser lens 45. The light is incident on the light receiving surface of the position detection element 5. In the case of such a configuration, the inner peripheral portion 54a
If the radius change rates of the outer peripheral portion 54b and the outer peripheral portion 54b are different or different from each other, different detection signals can be obtained. Therefore, there is an advantage that the detection signals can be detected with higher accuracy. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended.
Further, according to this configuration, since the light emitting means including the light source 3 and the light receiving means including the light position detecting element 5 are arranged in the vicinity of the rotating shaft 1, the diameter of the device can be further reduced. Also in this example, the deflecting means having the optical diameters of 90 degrees and 180 degrees can be used as in the second to seventh embodiments.

Further, two optical position detecting elements 5 can be used for one light source 3 by utilizing an optical system. Further, in this example, as another method, the rotating plate 5
It is also possible to stack 2 sheets of 4. Furthermore, it is possible to obtain a pulsed output by providing irregularities on either the inner or outer peripheral surface, the relative displacement can be detected by counting the number of pulses, and the other surface is the same as above. It is possible to change the radius according to the angle and to perform detection with good accuracy based on the signals obtained from both detection units. Note that this method can be applied even when the two rotary plates 54 are stacked.

Example 10. FIG. 6 is a principle diagram showing the relationship between the rotation angle θ of the rotary plate 40 and the radius r of the optical displacement detection device of still another embodiment of the present invention. In this FIG.
1 to 5 are denoted by the same reference numerals, and detailed description thereof will be omitted. Due to the principle of triangulation, this Figure 6A
In the case shown in, the following equation holds.

H / B = f / X (2)

Therefore, the spot X moving on the optical position detecting element 5 can be expressed as follows.

X = Bf / h = Bf / (Lr) (3)

That is, it is shown in relation to the radius r. Next, the relationship between the radius r and the rotation angle θ can be expressed as follows.

1 / (L−r) = aθ + b (4)

R = L−1 / (aθ + b) (5)

The radius r of the rotary plate 40 is determined using the above equation (5). As a result, the relationship between the output Vθ and the rotation angle θ becomes linear as shown in FIG. 6B, and the rotation angle can be detected accurately.

Example 11. FIG. 7 is a structural schematic diagram showing the configuration of an optical system of an optical displacement detecting device according to still another embodiment of the present invention. In FIG. 7, parts corresponding to those in FIGS. 1 to 6 are designated by the same reference numerals, and detailed description thereof will be omitted. In the figure, 60 is a reciprocating bearing, and as shown in this figure, the reciprocating bearing 60 is attached to both ends of the case 30. The two reciprocating bearings 60 support the reciprocating shaft 61 that reciprocates with respect to the case 30 to form a double shaft structure. Further, 62 is a reciprocating plate whose outer peripheral portion has an optical diffusion surface,
The reciprocating plate 62 is fixed to the reciprocating shaft 61.
It is made to reciprocate with respect to the case 60 in conjunction with. That is, the optical displacement detection device shown in this example has a structure for stroke displacement detection.

Reference numeral 41 is an element supporting substrate, 42 is a diaphragm member,
Reference numeral 43 is a collimator lens, 44 is a support member, and 45 is a condenser lens for condensing the light reflected from the optical diffusion surface of the reciprocating plate 62 on the optical position detection element 5. As shown in this figure, the element support substrate 45 is attached to the bottom portion inside the case 30, a light source 3 such as an LED is attached to the element support substrate 45 so that the light emitting direction thereof is the direction of the reciprocating axis 1, and the diaphragm member 42 is used for the light from the light source 3. The light source 3 is fitted and fixed to the outer peripheral surface so as to match the axes, and the supporting member 42 supports the collimator lens 43.
4 is fitted and fixed to the outer peripheral surface of the optical position detecting element 5,
The supporting lens 44 supports the condenser lens 45.

Here, the collimator lens 43 and the condenser lens 45 can be manufactured at a reduced cost by using a plastic molded product molded from an optical plastic such as polymethylmethacrylate (PMMA) or polycarbonate (PC). Next, the operation will be described. In FIG. 7, the light emitted from the light source 3 passes through the collimator lens 43 and the diaphragm 42, becomes a parallel light flux of a predetermined diameter, enters the outer peripheral portion of the reciprocating plate 62, and is reflected by the optical diffusion surface of the outer peripheral portion. To be done. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. When the reciprocating shaft 61 reciprocates here, the reciprocating plate 62 also reciprocates as shown by a chain double-dashed line in FIG. 7A, whereby the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5. To do. Therefore, the light incident position of the light position detecting element 5 becomes equal to the reciprocating plate 62, that is, the stroke displacement of the reciprocating plate 62, and the light position detecting element 5 is moved in the same manner as the conventional device described with reference to FIGS. Detection currents I1 and I2 are obtained from the detection electrodes. For example, if the detection currents I1 and I2 are detected by a detection circuit similar to the conventional device, the rotation angle V _Z corresponding to the light incident position X can be obtained.

This example is based on the principle of triangulation, and by increasing the distance change rate between the reflecting surface and the light receiving portion, it is possible to effectively detect the edge of the light receiving surface. If the photoelectric conversion layer of the optical position detecting element 5 is made of amorphous silicon, the maximum stroke range can be widened even if it is narrow. Further, since the light position detecting element of the light receiving surface having a small diameter can be detected with high accuracy, the device can be made small in diameter and small in size, and can have a biaxial structure, and the life of the light source can be extended. Further, the configuration for performing the 90-degree and 180-degree deflection described in the above-described second to seventh embodiments can be applied.

Example 12 Although the outer side portion of the reciprocating plate 62 is the optical diffusion surface in the eleventh embodiment, a reciprocating plate 63 having the inner side portion thereof as the optical diffusion surface may be used as shown in FIG. In this case, as shown in the figure,
The light emitted from the light source 3 passes through the collimator lens 43 and the diaphragm 42, becomes a parallel light flux of a predetermined diameter, enters the inner side portion of the reciprocating plate 63, and is reflected by the optical diffusion surface of the inner side portion. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. When the reciprocating shaft 61 reciprocates here, the reciprocating plate 63 also reciprocates, so that the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5. Accordingly, the light incident position of the light position detecting element 5 becomes equal to the reciprocating plate 63, that is, the stroke displacement of the reciprocating plate 63, and the light position detecting element 5 is moved in the same manner as in the conventional device described with reference to FIGS. The detection currents I1 and I2 are obtained from the detection electrodes. For example, if the detection currents I1 and I2 are detected by a detection circuit similar to the conventional device, the rotation angle VZ corresponding to the light incident position X can be obtained.

Similar to the eleventh embodiment, this example is also based on the principle of triangulation, and by increasing the distance change rate between the reflecting surface and the light receiving portion, the edge of the light receiving surface can be made effective. Since it can be detected, it can be detected accurately even if the detection stroke range is narrow, and the maximum stroke range can be widened when the photoelectric conversion layer of the light position detection element 5 is made of amorphous silicon. Further, since the light position detecting element of the light receiving surface having a small diameter can be detected with high accuracy, the device can be made small in diameter and small in size, and can have a biaxial structure, and the life of the light source can be extended. Further, the configuration for performing the 90-degree and 180-degree deflection described in the above-described second to seventh embodiments can be applied.

Example 13. In the eleventh embodiment, the outer peripheral portion of the reciprocating plate 62 is used as the optical diffusion surface, but as shown in FIG. 9, the reciprocating plate 64 is used in which both the inner peripheral portion and the outer peripheral portion are optical diffusion surfaces. The light source 3, the optical position detecting element 5, the supporting members 42 and 4 shown in FIG.
4, the collimator lens 43, and the condenser lens 45 may be arranged vertically. In this case, as shown in the figure, the light emitted from the light source 3 is transmitted through the collimator lens 43 and the diaphragm 42 and becomes a parallel light beam of a predetermined diameter, which is incident on the inner side portion of the reciprocating plate 64. Is reflected by the optical diffusion surface of. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. Here, when the reciprocating shaft 61 reciprocates, the reciprocating plate 64 reciprocates in the same manner, whereby the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5.

On the other hand, the light emitted from the light source 3 passes through the collimator lens 43 and the diaphragm 42, becomes a parallel light beam of a predetermined diameter, and enters the outer peripheral portion of the reciprocating plate 64, and the optical diffusion surface of this outer peripheral portion. Is reflected by. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. Here, when the reciprocating shaft 61 reciprocates, the reciprocating plate 64 reciprocates in the same manner, whereby the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5. Therefore, the light incident position of the light position detecting element 5 becomes equal to the reciprocating plate 64, that is, the stroke displacement of the reciprocating plate 64.
2 to 14, detection currents I1 and I2 are obtained from the detection electrodes of the optical position detecting element 5 as in the conventional device described with reference to FIGS. 2 to 14, and the detection currents I1 and I2 are detected by the same detection circuit as in the conventional device. Then, the rotation angle V _Z corresponding to the light incident position X can be obtained.

The outer side portion and the inner side portion respectively change the distance from the reciprocating shaft 61 according to the stroke, so that the outer side portion and the inner side portion have different distance change rates, or a deviation occurs. If so, different detection signals can be obtained, so that there is an advantage that the detection signals can be detected more accurately by comparing the detection signals of the two. Similar to the eleventh embodiment, this example is also based on the principle of trigonometric distance measurement, and by increasing the distance change rate between the reflecting surface and the light receiving portion, it is possible to effectively detect the edge of the light receiving surface. Even if the detection stroke range is narrow, the detection can be performed with high accuracy, and the maximum stroke range can be widened when the photoelectric conversion layer of the light position detection element 5 is made of amorphous silicon.

Further, since it is possible to accurately detect even a light position detecting element of a light receiving surface having a small diameter, the device can be made small in diameter and small in size, and can have a biaxial structure, so that the light source has a long life. be able to. Further, the configuration for performing the 90-degree and 180-degree deflection described in the above-described second to seventh embodiments can be applied. Further, by using the optical system, two light position detecting elements 5 are provided for one light source 3.
It is also possible to use.

Example 14 In the eleventh embodiment, the reciprocating plate 6
The outer peripheral portion of 2 is an optical diffusing surface, but two reciprocating plates 65 whose outer peripheral portion is an optical diffusing surface as shown in FIG.
The light from the light source 3 is reflected by the optical diffusion surfaces of the two reciprocating plates 65a and 65b and is made incident on the two optical position detecting elements 5 by the two condenser lenses 45, respectively. You may do it. In this case, as shown in the figure, the light emitted from the light source 3 becomes a parallel light flux having a predetermined diameter, enters the outer peripheral portions of the reciprocating plates 65a and 65b, and is reflected by the optical diffusion surfaces of the outer peripheral portions. To be done. Then, the reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. When the reciprocating shaft 61 reciprocates here, the reciprocating plate 6
5a and 65b respectively reciprocate in the same manner, whereby the spot lights focused on the optical position detecting element 5 move on the optical position detecting element 5, respectively.

Therefore, the light incident position of the light position detecting element 5 becomes equal to the stroke displacement of the reciprocating plates 65a and 65b, that is, the reciprocating plates 65a and 65b, and FIGS.
4, the detection currents I1 and I2 are obtained from the detection electrodes of the optical position detecting element 5 as in the conventional device described with reference to FIG. The rotation angle V _Z corresponding to the incident position X can be obtained. In this case, even the light position detecting element of the light receiving surface having a small diameter can be detected with high accuracy, so that the device can be made small in diameter and small in size, and can have a biaxial structure, and the light source can have a long life. it can. Further, the configuration for performing the 90-degree and 180-degree deflection described in the above-described second to seventh embodiments can be applied. Moreover,
When two reciprocating plates 65a and 65b are used, the reciprocating plate 6
One of 5a and 65b may be provided with irregularities so that a pulsed output can be obtained. In this case, the relative displacement can be detected by counting the number of pulses, and the other one can be obtained from the two detectors if the distance from the reciprocating shaft 61 is changed in accordance with the stroke as described above. Highly accurate detection can be performed based on the signal. This is also possible by using one reciprocating plate 65 that uses the inner and outer edges.

Example 15 FIG. 11 is a principle diagram showing the relationship between the stroke of the reciprocating plate 62 and the distance y between the reciprocating shaft 61 and the optical displacement detecting device according to still another embodiment of the present invention.
11, parts corresponding to those in FIGS. 1 to 10 are designated by the same reference numerals, and detailed description thereof will be omitted. Due to the principle of triangulation, the following equation holds in the case shown in FIG. 11A.

H / B = f / X (6)

Therefore, the spot X moving on the optical position detecting element 5 can be expressed as follows.

X = Bf / h = Bf / (K−y) (7)

That is, it is shown in relation to the distance y. Next, the relationship between the distance y and the stroke Z can be expressed as follows.

1 / (K−y) = aZ + b (8)

From the above equation (8), the distance y can be expressed as follows.

Y = K−1 / (aZ + b) (9)

The distance y of the reciprocating plate 62 from the reciprocating shaft 61 is determined using the above equation (9). This gives the output V
The relationship between Z and stroke displacement Z is linear as shown in FIG. 11B, and the rotation angle can be detected accurately.

Example 16. In the above embodiment, the light source 3
Although the case where the light position detecting element 5 and the light position detecting element 5 are separately attached to the element supporting substrate 45 by soldering or the like has been described, the light source 3 and the light position detecting element 5 may be simultaneously formed on the supporting substrate such as glass. Good, and the element support substrate 45
The light source 3 and the light position detection element 5 may be formed by processing a part of the surface of the. Further, it goes without saying that the optical system including the collimating means, the condenser means, and the deflecting means can be configured by combining various lenses, reflecting mirrors, prisms and the like other than those shown in the drawing.

[0070]

As described above, according to the first aspect of the present invention, the rotary shaft which is attached to the object to be measured or is a part of the rotary shaft and the rotary shaft which is attached to the rotary shaft to rotate integrally with the rotary shaft. A rotating plate whose part is an optical diffusing surface, a light source for irradiating the optical diffusing surface of the rotating plate with light, and a condensing optical system for condensing reflected light from the optical diffusing surface of the rotating plate, The rotating plate is provided with a light position detecting element disposed substantially at a light collecting position of the light collecting optical system, and the rotation plate has a distance between the light collecting position of the light collecting optical system and the light reflection position of the side peripheral portion of the rotating shaft. It is formed differently according to the rotation angle, and the displacement of the object to be measured is detected based on the light incident position on the light position detection element, so the rotation angle can be accurately measured regardless of the size of the angle detection range. Can be detected, the two-axis configuration is easy, and the light source has a long life. There is an effect that it is.

As described above, according to the second aspect of the present invention, the rotary shaft that is attached to the object to be measured or is a part of the rotary shaft and the rotary shaft that is attached to the rotary shaft and rotates integrally with the rotary shaft. A rotating plate having an optical diffusing surface, a light source for irradiating the optical diffusing surface of the rotating plate with light, and a condensing optical system for condensing reflected light from the optical diffusing surface of the rotating plate, The rotating plate is provided with a light position detecting element arranged substantially at a light collecting position of the light collecting optical system, and a distance between the light collecting position of the light collecting optical system and the light reflecting position of the side peripheral portion is equal to a rotation angle of the rotating shaft. According to the rotation angle of the rotary shaft and the radius of the rotary plate is determined according to the rotation angle of the DUT, based on the light incident position on the optical position detection element. Since the above-mentioned object to be measured is detected, accuracy is ensured regardless of the size of the angle detection range. Ku can detect the rotation angle, easy both axis configuration, and a small, inexpensive, yet there is an effect that the light source can be obtained a device lifetime.

As described above, according to the third aspect of the invention, the reciprocating shaft attached to or part of the object to be measured, and the reciprocating shaft attached to the reciprocating shaft, move integrally with the reciprocating shaft. A reciprocating plate as an optical diffusing surface, a light source for irradiating the optical diffusing surface of the reciprocating plate with light, and a condensing optical system for condensing the reflected light from the optical diffusing surface of the reciprocating plate, The reciprocating plate has a distance between the light condensing optical system and the light reflection position of the side portion of the reciprocating plate, depending on the stroke of the reciprocating shaft. Since it is configured to detect the displacement of the measured object based on the light incident position on the optical position detection element, the stroke displacement can be accurately detected regardless of the size of the stroke detection range. Easy configuration, small size, and long life of light source There is an effect that can be obtained location.

As described above, according to the invention of claim 4, the reciprocating shaft attached to or part of the object to be measured and the reciprocating shaft attached to the reciprocating shaft to move integrally, the side portion. A reciprocating plate as an optical diffusing surface, a light source for irradiating the optical diffusing surface of the reciprocating plate with light, and a condensing optical system for condensing the reflected light from the optical diffusing surface of the reciprocating plate, The reciprocating plate has a distance between the light condensing optical system and the light reflection position of the side portion of the reciprocating plate, depending on the stroke of the reciprocating shaft. The relationship between the stroke displacement of the reciprocating shaft and the side portion of the reciprocating plate is determined according to the stroke of the object to be measured. Since the displacement of the measuring object is detected, the stroke detection range It can accurately detect the stroke displacement regardless, both axes configuration easier, and a small, inexpensive, yet light source there is an effect that it is possible to obtain a device of long lifetime.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram of an optical system showing an embodiment of an optical displacement detection device according to the present invention.

FIG. 2 is a schematic structural view of an optical system showing another embodiment of the optical displacement detection device according to the present invention.

FIG. 3 is a schematic structural view of an optical system showing still another embodiment of the optical displacement detection device according to the present invention.

FIG. 4 is a structural schematic view of an optical system showing still another embodiment of the optical displacement detection device according to the present invention.

FIG. 5 is a structural schematic view of an optical system showing still another embodiment of the optical displacement detection device according to the present invention.

FIG. 6 is a principle diagram showing a relationship between a rotation angle and a radius of a rotary plate of the optical displacement detection device according to the present invention.

FIG. 7 is a structural schematic diagram showing a configuration of an optical system of still another embodiment of the optical displacement detection device according to the present invention.

FIG. 8 is a structural schematic diagram showing a configuration of an optical system of still another embodiment of the optical displacement detection device according to the present invention.

FIG. 9 is a structural schematic view showing a configuration of an optical system of still another embodiment of the optical displacement detection device according to the present invention.

FIG. 10 is a structural schematic diagram showing the configuration of an optical system of still another embodiment of the optical displacement detection device according to the present invention.

FIG. 11 is a principle diagram showing the relationship between the stroke of the reciprocating plate and the distance between the reciprocating shaft and the optical displacement detecting apparatus according to another embodiment of the present invention.

FIG. 12 is a configuration diagram showing a conventional optical displacement detection device.

FIG. 13 is a cross-sectional view showing an optical position detection element of a conventional optical displacement detection device.

FIG. 14 is a configuration diagram and a top view of another conventional optical rotation angle detection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating shaft 3 light source 5 optical position detecting element 43 collimator lens 45 condenser lens 40, 53, 54 rotating plate 61 reciprocating shaft 62, 64, 65a and 65b reciprocating plate

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[Procedure amendment]

[Submission date] September 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 2

[Correction method] Change

[Correction content]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

First, referring to FIG. 12, Japanese Patent Laid-Open No. 61-24
A conventional optical displacement detection device disclosed in Japanese Patent No. 6620 will be described. In the figure, reference numeral 1 denotes a rotary shaft connected to a rotary object as an object to be measured (not shown), and 2 denotes a rotary slit plate which is inserted through and attached to the rotary shaft 1 and which rotates about the rotary shaft 1 as a rotary shaft 2a.
Is a spiral slit formed on the rotary slit plate 2 and its radius changes in accordance with the rotation of the rotary slit plate 2, 3 is a light source, and 4 is within the range of the optical axis of the light source 3 and is rotated. fixed slit plate disposed parallel to each other and the slit plate 2, 4a are formed fixed slits so as to intersect with the helical slit 2a formed in the stationary slit plate 4 twice rolling slit plate 2, 5 denotes a light source 3 Since the light emitted from the rotary slit plate 2 is received through the spiral slit 2a of the rotary slit plate 2 and the fixed slit 4a of the fixed slit plate 4, the light receiving axis is arranged in the radial direction of the rotary slit plate 2. The light position detecting elements 6, 6 and 8 are detection electrodes for outputting a detection current of the light position detecting element 5, and 7 is for supplying a bias voltage from a power supply circuit (not shown) to the light position detecting element 5. Bias is a voltage application electrode.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016]

An optical displacement detecting device according to a first aspect of the present invention includes a rotary shaft which is attached to a part to be measured or is a part thereof, and a rotary shaft which is attached to the rotary shaft and integrally rotates. Then, with a rotating plate whose side peripheral portion is an optical diffusion surface,
A light source that irradiates the optical diffusion surface of the rotating plate with light, a condensing optical system that condenses the reflected light from the optical diffusion surface of the rotating plate, and the light condensing optical system is arranged at a substantially condensing position. has been a light position detecting element, the rotating plate distance between the light reflection position of the condensing optical system and the side peripheral portion is formed so as to be different according to the rotation angle of the rotary shaft, the light The displacement of the object to be measured is detected based on the light incident position on the position detecting element.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

According to a second aspect of the present invention, there is provided an optical displacement detecting device, which is attached to the object to be measured or is a part thereof, and a rotating shaft which is attached to the rotating shaft and integrally rotates to form a side peripheral portion. A rotating plate having an optical diffusing surface, a light source for irradiating the optical diffusing surface of the rotating plate with light, and a condensing optical system for condensing the reflected light from the optical diffusing surface of the rotating plate,
The rotating plate is provided with a light position detecting element arranged at a substantially condensing position of the condensing optical system, and the rotating plate has a distance between the condensing optical system and a light reflecting position of the side peripheral portion is a rotation angle of the rotating shaft. The relationship between the rotation angle of the rotary shaft and the radius of the rotary plate is determined according to the rotation angle of the measured object, and the relationship is determined based on the light incident position on the light position detection element. In addition, the displacement of the object to be measured is detected.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

[0020]

According to the first aspect of the present invention, the light incident position on the light position detecting element arranged at the substantially condensing position of the condensing optical system for condensing the reflected light from the optical diffusion surface of the rotating plate The rotation angle of the object to be measured is detected based on the principle of triangulation . This ensures that can accurately detect the rotation angle regardless of the magnitude of the angle detection range, easy both axes configuration and compact, the light source can be obtained a device lifetime.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

Example 3. Further, as shown in FIG. 2B, a flat reflecting mirror 48 having an angle of 45 degrees with respect to the optical diffusion surface of the rotating plate 40 may be supported and fixed to the case 30.
In this case, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is deflected by 90 degrees by the flat reflecting plate 48, and the deflected light is irradiated on the optical diffusion surface of the rotating plate 40.
Light reflected by the optical diffusion surface of the rotating plate 40 is reflected by the flat reflecting plate 48.
Is again deflected by 90 degrees, and the deflected light is incident on the light receiving surface of the optical position detecting element 5 by the condenser lens 45. In this case as well, similar to the above, even if the detection angle range is narrow, it is possible to detect with high accuracy, and the maximum detection angle range is approximately 2
Since it can be set to π, and even the light position detection element of the light receiving surface having a small diameter can be detected with high accuracy, the device can be made small in size and small in size, and can have a biaxial structure, thus extending the life of the light source. be able to.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

Example 4. Further, as shown in FIG. 2C, a mirror surface 30a having an angle of 45 degrees with respect to the optical diffusion surface of the rotary plate 40 may be formed on the surface of the case 30 by plating, vapor deposition or the like. In this case, the collimator lens 43 and the diaphragm member 42
The light from the light source 3 that has passed through is reflected by the mirror surface 30a by 90 degrees, and the optical diffusion surface of the rotating plate 40 is irradiated with the deflected light.
The light reflected by the optical diffusion surface of the rotating plate 40 is again deflected by 90 degrees on the mirror surface 30a, and the deflected light is condensed by the condenser lens 4
The light is incident on the light receiving surface of the optical position detecting element 5 by the light source 5. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

Example 6. Further, as shown in FIG. 3B, two flat reflecting mirrors 50 and 51 forming a narrow angle of 90 degrees with respect to the optical diffusion surface of the rotating plate 40 may be supported and fixed to the case 30. In this case, the light from the light source 3 which has passed through the collimator lens 43 and the diaphragm member 42 is reflected by the plane reflecting mirrors 51 and 5.
At 0, it is sequentially deflected by 90 degrees, for a total of 180 degrees.
The deflected light is applied to the optical diffusing surface of the rotating plate 40, and the light reflected by the optical diffusing surface of the rotary plate 40 is sequentially reflected by the plane reflecting mirrors 50 and 51.
The light is deflected by 0 ° for a total of 180 °, and the deflected light is incident on the light receiving surface of the optical position detection element 5 by the condenser lens 45. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

Example 7. Further, as shown in FIG. 3C, two mirror surfaces 30a and 30b may be formed on the surface of the case 30 by plating, vapor deposition, or the like, forming a narrow angle of 90 degrees with respect to the optical diffusion surface of the rotating plate 40. . In this case, the light from the light source 3 that has passed through the collimator lens 43 and the diaphragm member 42 is sequentially reflected on the mirror surfaces 30b and 30a by 90 degrees, for a total of 18 degrees.
The deflected light is deflected by 0 degrees, and the deflected light is applied to the optical diffusion surface of the rotating plate 40. The light reflected by the optical diffusion surface of the rotating plate 40 is deflected by 90 degrees in order by 90 degrees in total for a total of 180 degrees. The light is incident on the light receiving surface of the optical position detecting element 5 by the condenser lens 45. In this case as well, similar to the above, it is possible to detect with high accuracy even if the detection angle range is narrow, the maximum detection angle range can be set to approximately 2π, and even a light position detection element having a light receiving surface with a small diameter can be accurately detected. The device can have a small diameter and a small size, and can have a biaxial structure, so that the life of the light source can be extended.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

Here, the collimator lens 43 and the condenser lens 45 can be manufactured at a reduced cost by using a plastic molded product molded from an optical plastic such as polymethylmethacrylate (PMMA) or polycarbonate (PC). Next, the operation will be described. In FIG. 7, the light emitted from the light source 3 passes through the collimator lens 43 and the diaphragm 42, becomes a parallel light flux of a predetermined diameter, enters the outer peripheral portion of the reciprocating plate 62, and is reflected by the optical diffusion surface of the outer peripheral portion. To be done. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. When the reciprocating shaft 61 reciprocates here, the reciprocating plate 62 also reciprocates as shown by a chain double-dashed line in FIG. 7A, whereby the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5. To do. Therefore, the light incident position of the light position detecting element 5 becomes equal to the reciprocating plate 62, that is, the stroke displacement of the reciprocating plate 62, and the light position detecting element 5 is moved in the same manner as the conventional device described with reference to FIGS. The detection currents I1 and I2 are obtained from the detection electrodes. For example, if the detection currents I1 and I2 are detected by a detection circuit similar to the conventional device, the stroke V _Z corresponding to the light incident position X can be obtained.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

Example 12 Although the outer side portion of the reciprocating plate 62 is the optical diffusion surface in the eleventh embodiment, a reciprocating plate 63 having the inner side portion thereof as the optical diffusion surface may be used as shown in FIG. In this case, as shown in the figure,
The light emitted from the light source 3 passes through the collimator lens 43 and the diaphragm 42, becomes a parallel light flux of a predetermined diameter, enters the inner side portion of the reciprocating plate 63, and is reflected by the optical diffusion surface of the inner side portion. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. When the reciprocating shaft 61 reciprocates here, the reciprocating plate 63 also reciprocates, so that the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5. Accordingly, the light incident position of the light position detecting element 5 becomes equal to the reciprocating plate 63, that is, the stroke displacement of the reciprocating plate 63, and the light position detecting element 5 is moved in the same manner as in the conventional device described with reference to FIGS. The detection currents I1 and I2 are obtained from the detection electrodes. For example, if the detection currents I1 and I2 are detected by a detection circuit similar to the conventional device, a stroke VZ corresponding to the light incident position X can be obtained.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Correction target item name] 0055

[Correction method] Change

[Correction content]

On the other hand, the light emitted from the light source 3 passes through the collimator lens 43 and the diaphragm 42, becomes a parallel light beam of a predetermined diameter, and enters the outer peripheral portion of the reciprocating plate 64, and the optical diffusion surface of this outer peripheral portion. Is reflected by. Then, this reflected light is focused on the light receiving surface of the light position detecting element 5 by the condenser lens 45. Here, when the reciprocating shaft 61 reciprocates, the reciprocating plate 64 reciprocates in the same manner, whereby the spot light focused on the optical position detecting element 5 moves on the optical position detecting element 5. Therefore, the light incident position of the light position detecting element 5 becomes equal to the reciprocating plate 64, that is, the stroke displacement of the reciprocating plate 64.
2 to 14, detection currents I1 and I2 are obtained from the detection electrodes of the optical position detecting element 5 as in the conventional device described with reference to FIGS. 2 to 14, and the detection currents I1 and I2 are detected by the same detection circuit as in the conventional device. If you do, the strobe corresponding to the light incident position X
It can be obtained over click V _Z.

[Procedure Amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0059

[Correction method] Change

[Correction content]

Therefore, the light incident position of the light position detecting element 5 becomes equal to the stroke displacement of the reciprocating plates 65a and 65b, that is, the reciprocating plates 65a and 65b, and FIGS.
The detection currents I1 and I2 are obtained from the detection electrodes of the optical position detecting element 5 as in the conventional device described with reference to FIG. 4, and if the detection currents I1 and I2 are detected by the same detection circuit as in the conventional device, the light is detected. Stroke V _Z corresponding to incident position X
Can be obtained. In this case, even the light position detecting element of the light receiving surface having a small diameter can be detected with high accuracy, so that the device can be made small in diameter and small in size, and can have a biaxial structure, and the light source can have a long life. it can. Further, the configuration for performing the 90-degree and 180-degree deflection described in the above-described second to seventh embodiments can be applied. Further, when the two reciprocating plates 65a and 65b are used, one of the reciprocating plates 65a and 65b may be provided with irregularities so that a pulsed output can be obtained. In this case, the relative displacement can be detected by counting the number of pulses, and the other one can be obtained from the two detectors if the distance from the reciprocating shaft 61 is changed in accordance with the stroke as described above. Highly accurate detection can be performed based on the signal. Also,
This is also possible by using a single reciprocating plate 65 that uses the inner and outer edges.

[Procedure Amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0068

[Correction method] Change

[Correction content]

The distance y of the reciprocating plate 62 from the reciprocating shaft 61 is determined using the above equation (9). This gives the output V
The relationship between Z and stroke displacement Z is linear as shown in FIG. 11B, and stroke detection can be performed accurately.

Claims (4)

[Claims] 1. A rotary shaft attached to or part of an object to be measured, a rotary plate attached to the rotary shaft and integrally rotated, and a side peripheral portion of which serves as an optical diffusion surface, and the rotary plate. A light source for irradiating the optical diffusing surface with light, a condensing optical system for condensing the reflected light from the optical diffusing surface of the rotating plate, and a light arranged at a substantially condensing position of the condensing optical system. A position detecting element, and the rotating plate is formed such that the distance between the condensing optical system and the light reflecting position of the side peripheral portion varies depending on the rotation angle of the rotating shaft. An optical displacement detection device characterized in that the displacement of the object to be measured is detected based on the light incident position on the element. 2. A rotary shaft which is attached to or a part of a measured object, a rotary plate which is attached to the rotary shaft and rotates integrally, and a side peripheral portion of which serves as an optical diffusion surface, and the rotary plate. A light source for irradiating the optical diffusing surface with light, a condensing optical system for condensing the reflected light from the optical diffusing surface of the rotating plate, and a light arranged at a substantially condensing position of the condensing optical system. A position detecting element is provided, and the rotating plate is formed such that the distance between the condensing optical system and the light reflection position of the side peripheral portion varies depending on the rotation angle of the rotation shaft, and the rotation angle of the rotation shaft. The relationship between the radius of the rotary plate and the radius of the rotary plate is determined according to the rotation angle of the measured object, and the measured object is detected based on the light incident position on the optical position detection element. Optical displacement detection device. 3. A reciprocating shaft which is attached to or a part of an object to be measured, a reciprocating plate which is attached to this reciprocating shaft and moves integrally, and whose side portion is an optical diffusion surface, and this reciprocating plate. A light source for irradiating the optical diffusing surface with light, a condensing optical system for condensing the reflected light from the optical diffusing surface of the reciprocating plate, and a light arranged at a substantially condensing position of the condensing optical system. A position detecting element, the reciprocating plate is formed such that the distance between the condensing optical system and the light reflecting position of the side portion varies depending on the stroke of the reciprocating axis, and the light incident on the light position detecting element An optical displacement detection device characterized in that the displacement of the object to be measured is detected based on the position. 4. A reciprocating shaft which is attached to or a part of a body to be measured, a reciprocating plate which is attached to the reciprocating shaft and moves integrally, and a side portion of which serves as an optical diffusion surface, and the reciprocating plate. A light source for irradiating the optical diffusing surface with light, a condensing optical system for condensing the reflected light from the optical diffusing surface of the reciprocating plate, and a light arranged at a substantially condensing position of the condensing optical system. The reciprocating plate is formed such that the distance between the condensing optical system and the light reflection position of the side portion varies depending on the stroke of the reciprocating shaft. The relationship between the side portions of the plate is determined according to the stroke of the measured object, and the displacement of the measured object is detected based on the light incident position on the optical position detection element. Optical displacement detection device.