JP2019095305A - Position detector - Google Patents

Abstract

To provide a position detector that can reduce influence of expansion of a scale part generated due to such environmental changes as moisture changes and peripheral temperature changes, and a lens device using the position detector.SOLUTION: A position detector 1 includes: a scale part 10: a position detector 12 for detecting the position of the scale part 10; and a fixing part 13 for fixing at least one position of the scale part 10 to an attachment part 11. The fixing part 13 fixes the scale part 10 to the attachment part 11 at a position of the scale part 10 other than at an end part thereof in a side length direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a position detection device that detects displacement of a measurement target, and a device such as a lens device using the position detection device.

  Conventionally, as a displacement detection device for detecting displacement of a movement amount of a measurement object, a light source, a scale portion that reflects or transmits light from the light source, and is relatively displaced with respect to the light source, reflection or transmission by this scale portion And an optical encoder having a light receiving element for receiving the received light. An example is disclosed in Patent Document 1.

JP 2003-97936A

  In the technology described in Patent Document 1, the expansion and contraction of the scale portion due to the ambient temperature is absorbed by the springs disposed at both ends in the length measurement direction (longitudinal direction) of the scale portion. However, in the technique of Patent Document 1, since the scale portion is not fixed to the measurement target, the arrangement of the scale portion tends to be destabilized with respect to the measurement target regardless of the expansion and contraction.

  On the other hand, for example, when one end of the scale portion is connected by a spring and the other end is fixed to the measurement object, the above-mentioned arrangement is destabilized but the expansion and contraction of the scale portion is concentrated on one end side connected to the spring The measurement accuracy at this one end side is likely to be deteriorated.

  In view of the above problems, a position detection device according to one aspect of the present invention includes a scale unit, a position detection unit that detects the position of the scale unit, and a fixing unit that fixes one or more points of the scale unit to a mounting unit. The fixing portion fixes the scale portion to the mounting portion at a position other than the end portion in the side longitudinal direction of the scale portion.

  According to the present invention, it is possible to reduce the influence of expansion and contraction of the scale portion caused by the influence of environmental changes such as ambient temperature change and humidity change.

FIG. 1 is a schematic view of a position detection device 1 of a first embodiment. FIG. 6 is a view for explaining a base portion 11 and a fixing portion 13 of the scale portion of the first embodiment. FIG. 8 is a view for explaining a fixing method of the scale unit 10 of the first embodiment. FIG. 7 is a diagram for explaining a position detection device 2 of a second embodiment. FIG. 7 is a view for explaining a base portion 21 and a fixing portion 23 of a scale portion of the second embodiment. FIG. 7 is a view for explaining a fixing method of the scale unit 10 of the second embodiment. FIG. 7 is a view for explaining the relationship among the holding portion of the scale portion, the plate spring, and the fixing portion of the plate spring of the second embodiment. FIG. 8 is a diagram for explaining a position detection device 3 of a third embodiment. FIG. 10 is a view for explaining an integrated biasing unit of a third embodiment. FIG. 8 is a diagram for explaining a position detection device 4 of a fourth embodiment. FIG. 18 is a view for explaining the fixing position of the fixing portion of the scale portion of the fourth embodiment. FIG. 18 is a diagram for explaining the relationship between the subject distance and the focus ring position in the fourth embodiment. FIG. 18 is a diagram for explaining the expansion and contraction ratio of the end portion of the scale in Example 4. FIG. 16 is a diagram for explaining the relationship between focal length and zoom ring position in Embodiment 4. The figure which demonstrated the deflection | deviation of the position detection apparatus 5 of Example 5, and its scale part. The figure explaining bending of the scale part of the comparative example of Example 5. FIG. FIG. 7 is a view for explaining a lens device of Example 6;

  According to one aspect of the present invention, the scale unit is attached at one or more positions other than the end in the length measurement direction (typically the longitudinal direction) of the scale unit having the pattern area measured by the position detection unit. Fix the scale unit to the unit (such as the base of the position detection device). As a result, the expansion / contraction amount of the entire pattern area of the scale part due to environmental change etc. is distributed to each part at the ratio of the length in the length measurement direction of each part of the pattern area separated at the fixed position. The amount of expansion and contraction at each position of Thus, the measurement error at each of the positions measured by the position detection unit can be suppressed. The mounting unit of the scale unit and the position detection unit are movable relative to each other, and the measurement object whose movement amount is to be measured is mounted on the mounting unit side or the position detection unit side. The object to be measured itself may be an attachment. Here, the amount of expansion and contraction in the length measurement direction due to environmental changes between the attachment portion and the fixing portion can be ignored with respect to the amount of expansion and contraction of the pattern area of the scale portion. The mounting portion of the scale portion is, for example, in the case of a lens device, a cylinder or the like connected to an actuator that drives the lens.

Hereinafter, the present invention will be described in detail based on the illustrated embodiments.
Example 1
The position detection device 1 of the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a view for explaining a position detection device 1 according to this embodiment. The position detection device 1 includes a scale unit 10, a base 11 which is an attachment unit of the scale unit, a position detection unit 12, and a scale unit fixing unit 13. Including. In the present embodiment, the scale unit 10 is a scale unit of a known optical encoder, and the position detection unit 12 is configured of a position detection unit including a light source and a light receiving element. The scale unit 10 and the position detection unit 12 are disposed at a predetermined distance (for example, about 1 mm) in a direction perpendicular to the longitudinal direction (measurement direction). The position detection unit 12 receives the reflected light of the light from the light source with respect to the periodic pattern area configured on the scale unit 10 by the light receiving element, and thereby the position in the length measurement direction of the scale unit 10 that can be displaced relatively The relative displacement with respect to the detection unit 12 is detected. That is, a pattern for reflecting or transmitting light is formed in the scale unit 10, and the amount of light received by the light receiving element or the like changes according to the relative displacement of the scale unit 10. Therefore, the encoder detects the displacement of the object to be measured based on the detection signal output from the light receiving element in accordance with the change of the light amount or the like.

  In the configuration of FIG. 1, the measurement object is attached to the side of the base 11 to which the scale unit 10 is attached, but the measurement object may be connected to the position detection unit 12 side. In addition to the optical encoder, a magnetic encoder or the like may be used as the encoder. The encoder includes a signal processing circuit electrically connected to the position detection unit 12, a storage device, and the like. The position detection unit 12 includes, for example, a sensor integrated with light emitting and receiving, which is configured by packaging these members. It is a unit etc. The signal processing circuit performs, for example, interpolation processing of an encoder signal obtained by the light receiving element, writing / reading of a signal to a storage device, and output of a position signal.

  The scale unit 10 of this embodiment may be made of a flexible substrate such as polycarbonate, for example. Further, on the scale portion 2, a reflective film made of aluminum, chromium or the like is patterned as a pattern region of the scale portion. The base of the scale unit 10 may use a metal such as SUS.

  Next, a method of fixing the scale fixing portion 13 to the base 11 and a method of fixing the scale 10 to the scale fixing portion 13 will be described with reference to FIGS. 2 and 3. FIG. 2 is a view for explaining the scale fixing portion 13 and the base 11. FIG. 2 (a) is a front view, and FIGS. 2 (b) and 2 (c) are two side views. The scale fixing portion 13 mainly includes two holding plates 130 and four fixing screws (see FIG. 3), and the base 11 and the holding plate 130 are provided with four screw holes and through holes, respectively. .

  FIG. 3 is a view for explaining a fixing method of the scale unit 10. Fig.3 (a) is a front view, FIG.3 (b) is a side view. The scale unit 10 has a black-and-white pattern unit 100 provided in the longitudinal direction, and the position detection unit 12 detects the relative displacement of the scale unit 10 by reading the black-and-white pattern. Further, the scale portion 10 is disposed so as to be sandwiched between the base 11 and the two sandwiching plates 130, and four fixing screws are screwed into the screw holes of the base 11 through the through holes of the sandwiching plate 130, The scale 10 is fixed between the sandwiching plate 130 and the base 11. Note that four screw holes are provided in the base 11 so that the sandwiching plate 130 can be fixed at a predetermined position of the base 11, and the sandwiching plate 130 is an area of the scale 10 other than the pattern 100 described above. To reduce the

  As described above, since the scale 10 is fixed to the base 11 at both ends in the longitudinal direction, the scale 10 is reliably fixed to the measurement target side, and at the same time, the expansion and contraction of the scale 10 is suppressed on one end side in the longitudinal direction Ru. In the present embodiment, as shown in FIG. 1, the scale 10 is fixed to the base 11 at the center of the scale 10 (the ratio of the distance from the both ends is 1: 1).

  The present invention only needs to be configured so that expansion and contraction in the longitudinal direction occurs due to the influence of ambient temperature or the like in the position detection device. For example, if the scale portion is considered as a resistor, it can be applied to a potentiometer. A potentiometer is a resistor used for applications where the resistance value is to be changed frequently, such as for adjusting the volume (volume), for example, a portion called a C-shaped or line-shaped exposed resistor and a slider ( And sliding contacts). The position detection unit 12 detects the position of the slider on the resistor which is the scale unit 12 and reads the changing resistance value.

(Example 2)
A second embodiment of the present invention will be described. The position detection device 2 of the present embodiment differs from the position detection device 1 of the first embodiment in that the base portion has an annular shape. Moreover, in order to make the scale part which has elasticity expand, inside the base of this annular shape, the point which added the spring which biases a scale part differs.

  The position detection device 2 of this embodiment will be described with reference to FIGS. 2, 3 and 4 to 9. FIG. 4 is a diagram for explaining the configuration of the position detection device 2 of this embodiment. The position detection device 2 includes the scale unit 10, the base 21, the position detection unit 12, the scale unit fixing unit 23, and the scale unit holding unit 24. And a leaf spring 25 as a biasing member, and a leaf spring fixing portion 26.

  The base 21 is a plate member in which the flat base 11 according to the first embodiment is formed into an annular shape, and rotates around a center O of the annular ring. The scale portion fixing portion 23 is a member that fixes the scale portion 10 to the base 21, and the scale portion holding portion 24 is a member that holds an end portion of the scale portion 10 in the longitudinal direction. The plate springs 25 provided at both ends are known plate springs for biasing the scale unit 10 from one end to the other end in the longitudinal direction. In FIG. 4, the scale 10 is floated from the base 21 for convenience of description, but the scale 10 is disposed so as to extend to the inside of the base 21 by the scale fixing method described below.

  Next, the fixing method of the scale unit 10 will be mainly described with reference to FIGS. 3 and 5 to 7. FIG. 5 is a view for explaining the base portion 21 and the scale portion fixing portion 23. Fig.5 (a) is a front view, FIG.5 (b) is a side view. The scale fixing portion 23 mainly includes two pinching plates 230 and four fixing screws (see FIG. 6), and the base 21 and the pinching plate 230 are provided with four screw holes and through holes, respectively. . The scale fixing part 23 is different from the scale fixing part 13 of the first embodiment in that a curvature is provided on the contact surface with the base 21 along the inside of the annular base 21. .

  FIG. 6 is a diagram illustrating the details of the method of fixing the scale unit 10. The fixing method is the same as FIG. 3 of the first embodiment, and the four fixing screws are screwed into the screw holes of the base 21 through the through holes of the clamp plate 230 so that the scale 10 is between the clamp plate 230 and the base 21 It is fixed to

  Next, FIG. 7 is a view for explaining a method of biasing the end of the scale 10 in the longitudinal direction by the plate spring 25. As shown in FIG. The leaf springs 25 in FIGS. 7A and 7B perform biasing in opposite directions. The scale holding portion 24 has a U-shaped depression capable of holding the end in the longitudinal direction of the scale 10, and the scale holding portion 24 of the scale 10 wound along the inside of the annular base 21. The end is inserted into this recess. Further, a plate spring 25 is connected to the scale holding portion 24 so as to bias the end of the scale 10 in the longitudinal direction toward the other end. Furthermore, the plate spring 25 is connected to the plate spring fixing portion 26, and the plate spring fixing portion 26 is fixed to the base 21.

  The area of the leaf spring 25 can be replaced by, for example, the following structure. That is, a thin plate portion in which the thickness of the holding area at the end of the scale portion 10 is thinner than the effective area for signal detection is provided, and the thin area is fixed to the base 21 by the fixing portion. It is possible to form a region having a stiffness less than the stiffness. In addition, the holding area at the end of the scale unit 10 is a bellows-shaped bellows portion, which is fixed to the base 21 by the fixing unit, thereby forming a region having a rigidity smaller than the rigidity of the effective region of signal detection. can do. Here, the thin plate portion and the bellows portion are fixed to the base portion 21 so as to apply a biasing force to the central portion side of the scale portion 10.

  As described above, in the second embodiment, the same effect as that of the first embodiment can be obtained and, at the same time, the scale portion can be wound inside the annular base by biasing the scale portion with a plate spring or the like. It becomes.

(Example 3)
A third embodiment of the present invention will be described. FIG. 8 is a view for explaining the configuration of the position detection device 3 of this embodiment. The position detection device 3 includes the scale unit 30, the base 21, the position detection unit 12, the scale unit fixing unit 23, and the integrated biasing unit. Including 37.

  The scale portion 30 is different in scale portion length (longitudinal length) from the scale portion 10 of the second embodiment, and has a length close to the entire circumference of the base 21 which is an annular shape. Further, the integral biasing portion 37 is provided between both ends in the longitudinal direction of the scale portion 30.

  FIG. 9 is a view for explaining the details of the integral biasing portion 37. As shown in FIG. The integral biasing portion 37 is an integral member mainly composed of two scale portion holding portions 370 and a plate spring 371 disposed in the middle thereof. It urges toward the left and right outside of the part 37. The scale holder 370 and the plate spring 371 have the same functions as the scale holder 24 and the plate spring 25 of the second embodiment. The end portions in the longitudinal direction of the scale portion 30 are respectively inserted into the U-shaped depressions provided in the two scale portion holding portions 370, and the plate spring 371 is inserted into the scale portion 10 with respect to each end portion. Provides an urging force toward the central part.

  From the above, when the scale portion length has a length close to the entire circumference of the base 21 having the annular shape, the scale portion holding portion 24 and the plate spring 25 of the second embodiment are configured by one integrated biasing portion. As a result, the leaf spring fixing portion 26 of the second embodiment can be eliminated. Even in the case where the range of the length measurement is sufficiently shorter than the entire circumference of the base portion 21, it is possible to realize this embodiment by increasing the scale portion length. Moreover, although the leaf | plate spring 25 was used in the present Example, as long as it is the structure which biases a scale part, such as a coil spring, a biasing method does not matter.

(Example 4)
A fourth embodiment of the present invention will be described. The position detection device 4 of the present embodiment is different from the position detection device 3 of the third embodiment in the fixing position of the scale fixing portion 23 to the base 21 and is particularly characterized in the method of determining the fixing position.

  The position detection apparatus of this embodiment will be described with reference to FIGS. 8 and 10 to 14. FIG. 10 is a view for explaining the configuration of the position detection device 4 of this embodiment, which is the same as the position detection device 3 of FIG. 8 of the third embodiment except for the fixed position of the scale fixing portion 23. FIG. 11 is a view for explaining the fixing position of the scale fixing portion 23 in which the annular base portion 21 is expanded in a straight line shape, and the left end of the scale 30 in the longitudinal direction is P on the paper surface of FIG. The end of the frame is denoted by Q, and the fixed position of the scale section fixing portion 23 on the scale portion 30 is defined as G.

  The present embodiment is based on the following problem found by the present inventor. Depending on the measurement object, different detection accuracy may be required at the measurement position, and at the scale position where high detection accuracy is required, there is a demand to reduce the influence of the expansion and contraction of the scale due to the ambient temperature. The inventor has found that such a demand can be easily met by fixing the scale portion at an appropriate position other than at both longitudinal ends of the scale portion. Therefore, in the present embodiment, the base 21 is mechanically connected to, for example, a focus ring of a known lens device, and the position detection device 4 is used to detect the position of the focus ring.

  FIG. 12 is a diagram showing the relationship between the operation position of the focus ring of the lens apparatus used in the present embodiment (= the detection position of the position detection device 4) and the subject distance of focus. As can be seen from this figure, when the operation position is near the closest point, it is assumed that the change of the object distance with respect to the operation amount of the focus ring is larger (i.e., the focus sensitivity is higher) than near infinity. That is, it is assumed that the closest end P has the highest focus sensitivity.

Hereinafter, the method of determining the fixed position G of the scale portion fixing portion 23 will be described with reference to FIGS. The operation position on the near side in FIG. 11 is set to one end P of the scale unit 30 (hereinafter, the near end P), and the infinite side is similarly set to Q (hereinafter, the infinite end Q). Then, the expansion / contraction ratio at the near end P and the infinite end Q is the ratio of lengths on the scale of the near end P to the fixed position G and the infinite end Q to the fixed position G, and here, X: Y. Further, as shown in FIG. 12, assuming that the lower limit value of the focus measurement accuracy is d in terms of subject distance, let R and S be tolerances on the scale at the closest end P and the infinite end Q. The relationship (Expression 1) is established.
R <S (Equation 1)

Here, as shown in FIG. 13A, when the expansion / contraction width A of the scale unit 30 exceeds the allowable error S of the infinite end Q, the expansion / contraction width distributed to the infinite end Q side is equal to or less than the allowable error S (or The fixed position G is determined so that That is, as shown in FIG. 13 (b), the fixed position G is determined at a position where the following (Expression 2) and (Expression 3) are satisfied. Here, the expansion / contraction width X is an expansion / contraction width distributed to the closest end P side, and the expansion / contraction width Y is an expansion / contraction width distributed to the infinite end Q side.
Closest (P) side: Allowable upper limit R 伸縮 Stretchable width X ... (Equation 2)
Infinite (Q) side: Allowable upper limit S 伸縮 Stretchable width Y ... (Equation 3)

As an example of the detailed determination method, assuming that (R + S) ≧ A, it is preferable to set the ratio of R and S to satisfy the following (Expression 4) as a standard.
R: S = X: Y (Equation 4)

  Next, a modified embodiment of this embodiment will be described with reference to FIGS. 13 (b) and 14. FIG. FIG. 14 is a diagram showing the relationship between the operation position of the zoom ring of the lens apparatus used in this modification and the focal length of the zoom, having the highest nonlinearity of zoom sensitivity near H in the middle of the operation range There shall be a part.

  In such a case, the scale fixing portion 23 may be disposed near the intermediate position H. Moreover, when considering the fixed position of the scale part fixing part 23 including both ends (P, Q), the following is an example of a detailed determination method. Assuming that (R + S + T) ≧ A, a region on the scale portion in which the ratio of R and S satisfies (Equation 4) is searched, and the expansion / contraction width at position H is fixed to be T or less below that region The position of the portion 23 may be set as a fixed position. That is, the position of the fixing portion 23 is set such that the expansion / contraction width distributed to the length from the fixing position of the scale portion fixing portion 23 to the position H becomes T or less (or less). When the measurement accuracy of four or more locations is taken into consideration, it is preferable to set the position of the scale fixing portion 23 at which the measurement accuracy of each location is equal to or less than the allowable value as described above.

(Example 5)
A fourth embodiment of the present invention will be described. The present embodiment is different from the fourth embodiment mainly in the point of eliminating the deflection and the bending of the scale portion. Fig.15 (a) is a figure showing the state of bending of the scale part in FIG. 10 of Example 4, and the fixed position of the scale part fixing part 23 differs with respect to Example 3. FIG.

  In the case where the scale portion is elongated as in the third and fourth embodiments, the inventor may find that the scale portion does not overlap along the inside of the annular base 21 only by the bias at the end of the scale portion. Discovered that. In general, this deflection often occurs at the position of the scale portion other than the end of the scale portion to be biased, and the deflection is eliminated when the scale portion fixing portion 23 is disposed other than the end of the scale portion. Therefore, fixing the scale portion other than the end of the scale portion can realize the effect described in the above embodiment and the effect of eliminating the deflection of the scale portion by one scale portion fixing portion.

  FIG. 16 is a view of a comparative example illustrating the position detection apparatus in the case where one end of the scale portion is fixed to the base 21 and the other end is biased by the plate spring 25. As described above, in the case of biasing at one end of the scale portion, even if the same biasing is applied, greater stress is applied to the biased end, as compared with the case of biasing at both ends. As a result, it has also been found that the vicinity of the end of this biased scale portion is easily bent.

  In order to solve this problem, as shown in FIG. 15 (b), both ends are biased and the position of the scale portion other than the end is fixed to the base 21. In this way, the bending due to the biasing is eliminated, and the bending as shown in FIG. 16 can also be eliminated. Also in such a configuration, the arrangement of the scale fixing portion 23 may be determined in consideration of the measurement accuracy of each part of the scale described in the fourth embodiment so that the deflection in FIG. 16 can be eliminated.

(Example 6)
Next, with reference to FIG. 17, a lens apparatus (lens barrel of an imaging apparatus) mounted with the position detection apparatus 3 will be described. FIG. 17 is a schematic configuration diagram of a lens device or an imaging device (camera) in the present embodiment.

  In FIG. 17, the lens group 41 includes a drive lens 42, and a CPU 44 and an imaging device 45 are provided. The position detection unit 12, the scale unit 30, and the attachment unit or cylindrical body 21 are also provided. The image sensor 45 performs photoelectric conversion of the object image from the lens group 41 (drive lens 42). The lens group 41, the position detection unit 12, and the CPU 44 are provided in the lens apparatus, and the imaging element 45 is provided in the imaging apparatus main body. As described above, the lens apparatus of the present embodiment is configured to be replaceable with respect to the imaging apparatus main body. However, the present embodiment is also applicable to an imaging apparatus (camera) in which a lens apparatus and an imaging apparatus main body are integrally configured.

  The drive lens 42 constituting the lens group 41 is, for example, a zoom lens, and is movable in the Y direction which is the direction of the optical axis OA (the optical axis direction). The drive lens 42 may be another drive lens such as a focus lens. The cylindrical body 21 which also serves as the mounting portion of the scale portion is connected to an actuator (not shown) for driving the drive lens 42.

  When the cylinder 21 is rotated about the optical axis by an actuator or manually, the scale 30 is displaced relative to the position detector 12. Along with this, the drive lens 42 moves in the Y direction (arrow direction) which is the optical axis direction. A signal (encoder signal) corresponding to the displacement of the drive lens 42 obtained from the position detection unit 12 of the position detection device is output to the CPU 44. The CPU 44 generates a drive signal for moving the drive lens 42 to a desired position, and the drive lens 42 is driven based on the drive signal.

  The drive lens 42 generally has different optical sensitivities to displacement depending on the position as described in the fourth embodiment. Therefore, it is preferable to set the position and the number of the scale fixing portions as described in the fourth embodiment in consideration of the position of the position with high optical sensitivity.

  For example, when the drive lens 42 is a zoom lens, it may be designed such that the optical sensitivity to a change in position of the zoom lens is lower when the zoom lens is disposed closer to the infinity side. In this case, the position of the scale fixing portion may be set at the position of the cylindrical body corresponding to the close side of the zoom lens. On the other hand, when the area with high optical sensitivity to the position change of the zoom lens is positioned at the middle between the infinite side and the near side, it is preferable to use the form as in the modification of the fourth embodiment.

  As mentioned above, although the preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

1 · · Position detection device 10 · · Scale portion 11 · · · Base (attachment portion)
12 · · Position detection unit 13 · · Fixed unit

Claims (7)

Fixing is provided so as to detect the position of the mounting portion, the scale portion, the scale portion, and a position detection portion which is displaceable with respect to the scale portion, and fixes one or more positions of the scale portion to the mounting portion Have a department,
The position detecting device, wherein the fixing portion fixes the scale portion to the mounting portion at a position other than the end portion in the length measurement direction of the scale portion. In the position detection device according to claim 1,
The scale portion has elasticity, and the fixing position of the fixing portion to the attachment portion is determined based on the amount of expansion and contraction at the end in the length measurement direction of the scale portion caused by the elasticity. Position detection device. In the position detection device according to claim 1,
The said scale part has elasticity and the fixed position to the attachment part of the said fixing | fixed part is determined based on the detection precision by the position of the said scale part, The position detection apparatus characterized by the above-mentioned. The position detection device according to any one of claims 1 to 3.
The amount of expansion and contraction of the scale section is distributed to the sections at a ratio of the length in the length measurement direction of the sections of the scale section separated at the fixed position of the fixing section to the attachment section. The position detection device characterized in that the amount of expansion and contraction at each position is suppressed. The position detection device according to any one of claims 1 to 4.
The mounting portion has an annular shape, and the other end of the scale portion in the measurement direction is at the end portion in the length measurement direction of the scale portion so that the scale portion follows the annular shape of the mounting portion. A position detecting device characterized in that a biasing member is provided for biasing in a direction. The position detection device according to any one of claims 1 to 4.
The mounting portion has an annular shape, and between the two ends of the scale portion in the measurement direction, each end of the scale portion is the other end so that the scale portion follows the annular shape of the mounting portion. A position detecting device characterized in that one biasing member is provided for biasing in the direction of the part. A position detection device according to any one of claims 1 to 6, and a lens movable in the direction of the optical axis,
The mounting unit is a cylindrical body that rotates around the optical axis to move the lens in the direction of the optical axis, and the position detection unit detects the displacement of the rotation of the cylindrical body. Lens device.

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