JP7183010B2 - Rotation detection device, and lens device and imaging device using same - Google Patents

Description

The present invention relates to a rotation detection device used in various devices such as optical devices.

An optical device such as a camera or an interchangeable lens has a function of detecting rotation of an operation ring and causing the optical device to perform various operations. Some of such operation rings are capable of endless rotation, and a corresponding rotation detection device is required.

Conventionally, a rotation detection device has a scale provided on the inner circumference of an operation ring and a photosensor capable of relative rotation with the scale, and outputs a signal corresponding to a periodic pattern provided on the scale from the photosensor. Are known. Patent Literature 1 discloses an optical device having a scale formed by attaching a sheet to the inner peripheral surface of an operation ring.

JP 2016-110070 A

However, in order to attach the sheet disclosed in Patent Document 1 to the inner peripheral surface of the operation ring without floating, it is necessary to attach the sheet while applying a pulling force to the sheet. At this time, variations in the tensile force may cause variations in the length of the scale in the circumferential direction and errors in the width of the gap between the ends of the sheet in the circumferential direction, resulting in a decrease in rotation detection accuracy. Further, it is possible to adjust the length of the scale and the width of the gap between both ends by peeling off the sheet attached to the inner peripheral surface of the operation ring and reattaching it, but the work is time-consuming.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a rotation detection device, a lens device, and an image pickup device that allow a scale member to be attached to the inner peripheral surface of an annular member more accurately and easily than in the past.

A rotation detecting device according to one aspect of the present invention includes an annular member, a flexible scale member attached to the inner peripheral portion of the annular member, and a scale member facing the scale member. the inner peripheral portion of the annular member includes a plurality of contact surfaces that contact the scale member and a plurality of contact surfaces that differ from the contact surfaces in the direction of the rotational axis of the annular member. a circumferential length of an inscribed circle of the plurality of contact surfaces is shorter than a length in a longitudinal direction of the scale member, and the circumferential length of the inner circumferential surface is the length of the scale member; Each of the plurality of contact surfaces and the inner peripheral surface are smoothly connected in the rotation axis direction.

A lens device as another aspect of the present invention has an imaging optical system and the rotation detection device.

An imaging apparatus as another aspect of the present invention includes the lens device, an imaging element that photoelectrically converts an optical image formed through the lens device, and a camera body that holds the imaging element.

Other objects and features of the invention are described in the following embodiments.

According to the present invention, it is possible to provide a rotation detection device, a lens device, and an image pickup device that enable a scale member to be attached to the inner peripheral surface of an annular member more accurately and easily than before.

1 is an external perspective view of an imaging device according to this embodiment; FIG. 1 is a block diagram of an imaging device according to this embodiment; FIG. 2 is an exploded perspective view of the rotation detection device according to the embodiment; FIG. 2 is a cross-sectional view of the rotation detection device according to the embodiment; FIG. FIG. 4 is an explanatory diagram of a reflection scale in this embodiment; FIG. 4 is an explanatory diagram of an operation ring according to the embodiment; FIG. 4 is an explanatory diagram of an operation ring according to the embodiment; FIG. 4 is a developed view showing the relationship between the reflection scale and the inscribed circle in the embodiment; FIG. 4 is a developed view showing the relationship between a reflection scale, an inscribed circle, and an inner circumference connecting line; FIG. 4 is a developed view showing the relationship between the reflective scale and the inscribed circle in this embodiment under a temperature environment. FIG. 4 is a developed view showing the relationship between the length of the reflective scale, the length of the circumference of the inscribed circle, and the total length of the scale receiving portion in the present embodiment. It is a figure which shows the bending of the reflective scale in this embodiment. FIG. 5 is a cross-sectional view showing a method of attaching the reflective scale to the operation ring in this embodiment; FIG. 4 is a perspective view showing a state in which the reflective scale according to the present embodiment is arranged on the rotary sliding portion of the operation ring; FIG. 4 is an explanatory diagram of a rotation detection method according to the embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, an imaging device 100 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is an external perspective view of an imaging device 100. FIG. FIG. 2 is a block diagram of the imaging device 100. As shown in FIG. The image capturing apparatus 100 includes a camera body 1 and an interchangeable lens (lens device) 2 detachable from the camera body. An operation ring 21 as an endlessly rotatable operation member is provided on the outer circumference of the interchangeable lens 2 .

The camera body 1 has a camera control section 11 and an imaging device 12 . The camera control section 11 can communicate with the lens control section 26 of the interchangeable lens 2 . The imaging device 12 is held in the camera body 1, photoelectrically converts an optical image formed through the interchangeable lens 2, and outputs image data. The interchangeable lens 2 has the aforementioned operation ring 21 , detection section (detection means) 221 , focus lens 241 , focus driving section 242 , diaphragm unit 251 , diaphragm driving section 252 , and lens control section 26 .

The detector 221 is composed of a photoreflector that receives reflected light from a reflective scale, which will be described later, and outputs a detection signal according to the rotation of the operation ring 21 . The lens control section 26 can detect the rotation direction, rotation amount, and rotation speed of the operation ring 21 using the detection signal from the detection section 221 . The focus lens 241 is provided in an imaging optical system (not shown) accommodated in the interchangeable lens 2 and is a lens that adjusts the focal position of the imaging optical system. The focus drive unit 242 is an actuator for moving the focus lens 241 in the optical axis direction of the imaging optical system. The diaphragm unit 251 forms a diaphragm opening with a plurality of diaphragm blades, and adjusts the amount of light passing through the diaphragm opening by changing the size of the diaphragm opening. The aperture drive unit 252 is an actuator that drives aperture blades of the aperture unit 251 . The lens control unit 26 acquires an operation signal from the detection unit 221 and communicates with the camera control unit 11 provided in the camera body 1, or a microcomputer that controls the focus drive unit 242 and the aperture drive unit 252. is.

Either the function of driving the focus lens 241 to adjust the focus position or the function of driving the aperture unit 251 to adjust the amount of light is assigned to the operation ring 21 according to user settings in the camera body 1 . ing. The lens control unit 26 detects the direction and amount of rotation of the operation ring 21 from the detection signal from the detection unit 221, and uses the detection result to control the focus driving unit according to the function assigned to the operation ring 21. 242 or aperture driver 252 . Further, the lens control unit 26 receives a focus drive command for AF and an aperture drive command for AE from the camera body 1 (camera control unit 11) , and controls the focus drive unit 242 and the aperture drive unit 252. .

Next, a rotation detection device 200 including a detection section 221 that detects rotation of the operation ring 21 will be described with reference to FIGS. 3 to 5. FIG. FIG. 3 is an exploded perspective view of the rotation detection device 200. FIG. FIG. 4 is a cross-sectional view of the rotation detection device 200. As shown in FIG. FIG. 5 is an explanatory diagram of the reflection scale (scale member) 27 in the rotation detection device 200. As shown in FIG. In the following description, the object side in the optical axis direction is called the front side, and the image side is called the rear side. A direction around the optical axis is called a circumferential direction, and a direction perpendicular to the optical axis is called a radial direction.

The rotation detection device 200 includes a fixed cylinder (fixed member) 23 , an operation ring 21 , a reflective scale 27 as a scale member, and a detection section 221 . The fixed barrel 23 is a base member of the interchangeable lens 2. The fixed barrel 23 is provided with a rotation receiving portion 232 for guiding the rotation of the operation ring 21 and a sensor fixing portion 231 for fixing (attaching) the detecting portion 221. ing. The operation ring 21 is an operation member as described above, and is an annular member to which the reflective scale 27 is attached on the inner peripheral portion thereof. In this embodiment, the operation ring 21 is an operation member and an annular member, but the operation member and the annular member may be separate members.

The rotation detection device includes a fixed cylinder 23 , an operation ring 21 , a reflective scale (scale member) 27 and a detector 221 . The fixed barrel 23 is a base member of the interchangeable lens 2. The fixed barrel 23 is provided with a rotation receiving portion 232 for guiding the rotation of the operation ring 21 and a sensor fixing portion 231 for fixing the detection portion 221. . The operation ring 21 is an operation member as described above, and is an annular member to which the reflective scale 27 is attached on the inner peripheral portion thereof. In this embodiment, the operation ring 21 is an operation member and an annular member, but the operation member and the annular member may be separate members.

The detection unit 221 includes a sensor (photoreflector) 221a and a sensor FPC 221b on which the sensor 221a is mounted, and is fixed to the sensor fixing portion 231 of the fixed cylinder 23. As shown in FIG.

The inner peripheral portion of the operation ring 21 has a scale receiving portion 211 and rotary sliding portions 212A and 212B provided on the front and rear sides of the scale receiving portion 211, respectively. The scale receiving portion 211 is a contact surface with which the reflective scale 27 is attached and contacts. As shown in FIG. 4, the rotary sliding portion 212A is rotatably engaged with the rotation receiving portion 232 of the fixed barrel 23, and the rotary sliding portion 212B is the rotation receiving portion of the front barrel 28 connected to the fixed barrel 23. 282 to be rotatably engaged. Thereby, the rotation axis (rotation center axis) of the operation ring 21 with respect to the fixed barrel 23 and the front barrel 28 is determined. Thus, the rotary sliding portions 212A and 212B are bearing portions that engage with the rotation receiving portions 232 and 282 to determine the rotation axis of the operation ring 21. As shown in FIG. As will be described later, in addition to functioning as a bearing, the rotary sliding portion 212A is also used when incorporating the reflective scale 27 into the operation ring 21 .

FIG. 5 is an explanatory diagram of the reflective scale 27, showing the pattern surface and the side surface of the reflective scale 27 in a planar manner. The reflective scale 27 is a flexible sheet member in which a plurality of reflective portions 27a and a plurality of non-reflective portions 27b are alternately arranged on its pattern surface. It is bent into a ring and attached as shown in . The reflecting portion 27a and the non-reflecting portion 27b have different reflectances (the reflecting portion 27a has a higher reflectance than the non-reflecting portion 27b). That is, a pattern whose reflectance changes periodically is formed on the pattern surface.

In FIG. 5, the width of the reflective portion 27a in the longitudinal direction (circumferential direction) of the reflective scale 27 is Ra, and the width of the non-reflective portion 27b is Rb. Also, let Rp be the length from one reflecting portion 27a to the next reflecting portion 27a (predetermined pitch: hereinafter referred to as pattern pitch). In this embodiment, the length L1 of the reflection scale 27 in the longitudinal direction is set to an integral multiple (×n) of the pattern pitch Rp. A reflective portion 27a as part of the pattern is provided on one of both ends of the reflective scale 27 in the longitudinal direction, and a non-reflective portion 27b is provided on the other as another part of the pattern.

Also, as shown in FIG. 5, let t be the thickness of the reflective scale 27 when viewed from the side. The thickness t includes the thickness of the base material portion and the pattern forming portion. The base material portion is made of a flexible plate made of a metal material such as SUS or a resin material such as PET. In the pattern forming portion, the pattern described above is formed by printing a non-reflective surface on a reflective material. The surface of the pattern forming portion (lower surface in FIG. 5) is the pattern surface described above.

Next, the scale receiving portion 211 of the operation ring 21 will be described with reference to FIGS. 6 and 7. FIG. 6 and 7 are explanatory views (sectional views) of the scale receiving portion 211 of the operation ring 21. FIG. As shown in FIG. 6, the scale receiving portion 211 is configured by alternately arranging a plurality of contact portions (contact surfaces) 211a and a plurality of recesses (non-contact portions) 211b in the circumferential direction. As shown in FIG. 7, an inscribed circle A is a circle that inscribes the plurality of contact portions 211a. The recessed portion 211b is a portion that is recessed radially outward of the inscribed circle A. As shown in FIG. Also, the shortest distance from the center O of the inscribed circle A to the contact portion 211a is R, and the circumferential length of the inscribed circle A is L2.

FIG. 8 is a developed view showing the relationship between the reflective scale 27 and the inscribed circle A. As shown in FIG. The length L1 of the reflection scale 27 is set longer than the circumference length L2 of the inscribed circle A by a predetermined value L3. Conversely, the circumferential length L2 of the inscribed circle A is set shorter than the length L1 of the reflective scale 27 by a predetermined value L3. That is, the shortest distance R that determines the contact portion 211a is set by the length L1 of the reflective scale 27 and the predetermined value L3. The non-contact portion 211b is provided so as to be positioned outside the inscribed circle A. As shown in FIG.

The predetermined value L3 is determined under the following two conditions, even if there are variations in the dimensions of the reflecting scale 27 and the operating ring 21 within the component tolerances and a difference in the amount of deformation due to a difference in coefficient of linear expansion between the reflecting scale 27 and the operating ring 21. is set to satisfy FIGS. 9A and 9B show examples when these conditions are not met. In other words, the relationships shown in FIGS. 9A and 9B do not satisfy Condition 1 and Condition 2 below.

Condition 1: The circumferential length L2 of the inscribed circle A is shorter than the length L1 of the reflective scale 27 .

Condition 2: The total length L4 of the length along the two surfaces (slopes) connecting all the contact portions 211a on the scale receiving portion 211 and the two concave portions 211b on both sides of each of them is Be longer than the length L1.

With reference to FIG. 10, the maximum value L3'(A) for satisfying the condition 1 of the distance between both ends of the reflecting scale 27 when the reflecting scale 27 is bent into a ring shape will be described. FIG. 10 is a developed view showing the relationship between the reflective scale 27 and the inscribed circle A under a temperature environment.

First, the case where the coefficient of linear expansion of the material (resin) of the operation ring 21 is greater than the coefficient of linear expansion of the material of the base material portion of the reflective scale 27 will be described. Assume that the tolerance of the length L1 of the reflection scale 27 is ±α. When the tolerance of the shortest distance R from the center of the inscribed circle A to the contact portion 211a is ±β, the increase C from the design value when the circumference length of the inscribed circle A is maximized is given by the following formula: (1).

C=2・β・π … (1)
Let L1′ be the length of the reflective scale 27 considering the amount of change due to the coefficient of linear expansion at the highest temperature in the operating temperature range of the interchangeable lens 2, and L2′ be the circumference of the inscribed circle A. By adding the value in the direction in which the distance between the ends of the reflection scale 27 increases from these values, the maximum value L3'(A) is expressed by the following equation (2).

L3′(A)=α+2・β・π+(L2′−L1′) … (2)
When the coefficient of linear expansion of the material of the operation ring 21 is smaller than the coefficient of linear expansion of the material of the base material portion of the reflective scale 27, the distance between both ends of the reflective scale 27 is the largest at low temperatures. Therefore, if the length of the reflective scale 27 at the lowest temperature in the operating temperature range is L1'' and the circumference of the inscribed circle A is L2'', the maximum value L3' (B) is given by the following equation (3). is represented as

L3′(B)=α+2・β・π+(L1″−L2″) … (3)
Condition 2 will be described using the amount of interference between both ends of the reflective scale 27 (hereinafter referred to as the amount of interference between both ends). L3'(B) is the maximum value of the amount of interference between both ends of the reflecting scale 27 when the coefficient of linear expansion of the material of the operating ring 21 is greater than the coefficient of linear expansion of the material of the base material of the reflecting scale 27, and the former is smaller. is L3'(A).

From the above, the predetermined value L3 is set within the range shown in the following formula (4) or (5). That is, when the coefficient of linear expansion of the material of the operation ring 21 is greater than the coefficient of linear expansion of the material of the base material portion of the reflective scale 27, the predetermined value L3 is set within the range of formula (4) as shown in FIG. . FIG. 11 is a developed view showing the relationship between the reflection scale length, the circumferential length of the inscribed circle, and the total length of the scale receiving portion.

L3'(A)<L3<L4-L1-L3'(B) … (4)
On the other hand, when the coefficient of linear expansion of the material of the operation ring 21 is smaller than the coefficient of linear expansion of the material of the base material portion of the reflective scale 27, the predetermined value L3 is set within the range of formula (5).

L3'(B)<L3<L4-L1-L3'(A) (5)
From the above results, the predetermined value L3 that satisfies the conditions 1 and 2 can be derived, and the value L2 obtained by subtracting the predetermined value L3 from the length L1 of the reflective scale 27 is the circumferential length of the inscribed circle A. Determine the shortest distance R.

By constructing the scale receiving portion 211 as described above, the reflective scale 27 is pressed against the contact portion 211a and both ends are brought into contact with each other regardless of variations in component precision and temperature changes, thereby supporting the scale receiving portion. It is held in section 211 . The pressing force against the contact portion 211a is applied by the biasing force generated by the ring-shaped bending of the reflective scale 27 having elasticity. Further, the contact force between the both ends is given by the biasing force generated by the inward bending of the plurality of concave portions 211b of the reflective scale 27 .

12A and 12B are diagrams showing the deflection of the reflective scale 27. FIG. The difference between the actual length L1 of the reflective scale 27 and the circumferential length L2 of the inscribed circle A is absorbed by changing the deflection amount of the reflective scale 27 into the concave portion 211b as shown in FIG. Thereby, it is possible to control the deformation direction of the reflective scale 27 so as not to be radially inward.

If the predetermined value L3 is set to a large value within the above conditions, the amount of deflection of the reflection scale 27 into the concave portion 211b is increased , and the contact force between the ends and the biasing force against the contact portion 211a are increased. On the other hand, if the predetermined value L3 is set to a small value within the above conditions, the amount of deflection of the reflection scale 27 into the concave portion 211b becomes small, and the contact force between the ends and the biasing force against the contact portion 211a are reduced. . Plastic deformation of the reflective scale 27 can be suppressed by reducing the contact force between the ends.

By bringing both ends of the reflective scale 27 into contact with each other as in this embodiment, the reflection at the joint between both ends and the variation in the pitch of the non-reflecting portion 27b are not affected by assembly errors of the rotation detector, and the reflection The variation is within the part tolerance of the scale 27 . Since the non-reflecting portion 27b is provided at one end of the reflective scale 27, a minute non-reflecting area generated at the joint is detected as being the same as the adjacent non-reflecting portion 27b.

The scale pitch Rp can be reduced by adopting the configuration in which both ends of the reflective scale 27 are brought into contact with each other as in this embodiment. As a result, the rotation detection device of this embodiment can detect the rotation of the operation ring 21 with high resolution, and can be used to perform high-precision position control of the focus lens 241 as well.

Next, with reference to FIGS. 13 and 14, a method of attaching (assembling) the reflective scale 27 of the present embodiment to the operation ring 21 will be described. 13A and 13B are sectional views showing a method of attaching the reflective scale 27 to the operation ring 21. FIG. FIG. 14 is a perspective view showing a state in which the reflective scale 27 is arranged at the mounting preparation diameter.

As shown in FIG. 13, the operation ring 21 includes a contact portion (contact surface) 211a forming an inscribed circle A, and a rotary sliding portion (inner peripheral surface) having a predetermined diameter (mounting preparation diameter). 212A, slope 235, and scale abutting portion 214. FIG. The circumferential length of the rotary sliding portion 212A is set to be equal to or longer than the length L1 of the reflective scale 27. As shown in FIG. That is, the mounting preparation diameter of the rotary sliding portion 212A is larger than the diameter of the inscribed circle A. As shown in FIG. The slope 235 is a surface that smoothly and continuously connects the contact portion 211a and the rotary sliding portion 212A. Note that the inclined surface 235 is not limited to a flat surface, and may be a curved surface as long as it smoothly and continuously connects the contact portion 211a and the rotary sliding portion 212A. That is, slope 235 includes at least one of a flat portion and a curved portion. The scale abutting portion 214 is a stopper portion for determining the position of the reflective scale 27 in the rotation axis direction.

As shown in FIG. 14, since the circumferential length of the rotary sliding portion 212A having the mounting preparation diameter is longer than the length L1 of the reflective scale, the rotary sliding portion 212A is not subjected to the tension force of the reflective scale 27. , can be easily incorporated into the rotary sliding portion 212A of the operation ring 21. As shown in FIG. Position (A) in FIG. 13 shows a state in which the reflective scale 27 is arranged on the rotary sliding portion 212A. From this state, the side surface of the reflective scale 27 is pushed in the direction of arrow F in FIG. At this time, since the rotary sliding portion 212A and the contact portion 211a are connected by the slope 235, the reflective scale 27 is smoothly pushed into the position (B) where it engages with the contact portion 211a and is attached to the operation ring 21. . By the above method, the reflective scale 27 is attached to the inner peripheral side of the contact portion 211a, which is the position to be detected, while applying tension in both the radial direction and the circumferential direction.

In this embodiment , it is preferable that the width W1 of the rotary sliding portion 212A in the direction of the rotation axis is set to be different from the width W2 of the reflection scale 27 in the direction of the rotation axis. When the width W1 is longer than the width W2 (W1>W2), it becomes easier to apply the force indicated by the arrow F when pushing the reflective scale 27 from position (A) to position (B). On the other hand, when the width W1 is shorter than the width W2 (W1<W2), the reflective scale 27 can be pushed in parallel from position (A) to position (B). In either case, it becomes easier to push in the reflective scale 27 .

Next, a rotation detection method by the rotation detection device 200 will be described with reference to FIGS. 4 and 15. FIG. FIG. 15 is an explanatory diagram of the rotation detection method. The sensor 221 a is fixed to the sensor fixing portion 231 of the fixed barrel 23 so as to face the pattern surface of the reflective scale 27 attached to the scale receiving portion 211 of the operation ring 21 . The sensor 221a has a light-emitting portion that emits light toward the pattern of the reflective scale 27, and two light-receiving portions A and B that receive the light reflected by the reflecting portion 27a of the pattern. The center interval between the light receiving portion A and the light receiving portion B coincides with the center interval in the circumferential direction between the adjacent reflecting portion 27a and the non-reflecting portion 27b of the reflecting scale 27. As shown in FIG.

When the operation ring 21 rotates with respect to the fixed cylinder 23, the reflective scale 27 moves (rotates) with respect to the sensor 221a, and the light from the light-emitting portion of the sensor 221a reaches the reflective portion 27a and the non-reflective portion 27b of the reflective scale 27. irradiated alternately. While the operation ring 21 rotates in one direction, when a certain reflecting portion 27a is irradiated with light, one of the light receiving portions A and B receives the light reflected by the reflecting portion 27a. After that, when the next reflecting portion 27a is irradiated with light, the light reflected by the reflecting portion 27a is received by the other of the light receiving portions A and B. FIG.

As shown in FIG. 15, the outputs from the light receiving units A and B are High when the amount of reflected light received exceeds a certain threshold, and are Low when the amount is below the threshold. Therefore, when the operation ring 21 rotates in one direction, high and low signals are output from the light receiving portions A and B with a phase difference of 90°. In FIG. 15, for example, "H/L" indicates that the output from the light receiving portion A is High and the output from the light receiving portion B is Low.

The lens control section 26 detects the rotation direction, the amount of rotation, and the rotation speed of the operation ring 21 from the combination of the outputs of the light receiving sections A and B. FIG. Specifically, for example, the amount of rotation for one pulse is detected when the outputs of the light receiving portions A and B change from "H/L" to "L/L". Also, the rotation speed is detected from the number of pulses detected within a certain period of time. Furthermore, by detecting the switching of the outputs of the light receiving portions A and B from "H/L" → "H/H" → "L/H" → "L/L" → "H/L", , detects that the rotation direction of the operation ring 21 is the direction indicated by the encircled circle 1 in the figure. Further, by detecting the switching of the outputs of the light receiving portions A and B from "H/L" → "L/L" → "L/H" → "H/H" → "H/L", , detects that the rotation direction of the operation ring 21 is the direction indicated by the encircled circle 2 in the drawing. As described above, in the present embodiment, the sensor 221a and the reflective scale 27 are arranged to face each other, and the sensor 221a and the reflective scale 27 are moved relative to each other. Operation direction can be detected.

In this embodiment, the circumferential length L2 of the inscribed circle A of the plurality of contact portions 211a is shorter than the length L1 of the reflecting scale 27, and the circumferential length of the rotary sliding portion 212A is equal to the length L1 of the reflecting scale 27. That's it. Further, each of the plurality of contact portions 211a and the rotary sliding portion 212A are smoothly connected to each other in the rotation axis direction via the slope 235. As shown in FIG. With such a configuration, the reflective scale 27 can be attached to the operation ring 21 without using an adhesive. Therefore, according to this embodiment, it is possible to provide a rotation detection device, a lens device, and an imaging device that can easily attach a scale member to the inner peripheral surface of an annular member (operation ring 21) with high accuracy. can be done.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist.

For example, in the present embodiment, a rotation detection device mounted on an operation ring provided in a lens device for a camera (imaging device) has been described, but the present invention is not limited to this. The rotation detection device of the present invention can be applied to, for example, volume control knobs of audio equipment, control knobs of linear motion stages, and the like. Further, the rotation detection device can be used not only as operation detection means, but also for detecting rotation of a motor, for example.

21 operation ring (annular member)
27 reflective scale (scale member)
211a contact portion (contact surface)
212A Rotation sliding portion (inner peripheral surface)
221 detection unit (detection means)

Claims (10)

an annular member;
a flexible scale member attached to the inner periphery of the annular member;
detection means facing the scale member and detecting relative rotation with the scale member;
The inner peripheral portion of the annular member has a plurality of contact surfaces that come into contact with the scale member, and an inner peripheral surface that is provided at a position different from the contact surface in the direction of the rotational axis of the annular member. ,
the circumferential length of the inscribed circle of the plurality of contact surfaces is shorter than the length of the scale member in the longitudinal direction;
the circumferential length of the inner peripheral surface is equal to or greater than the length of the scale member;
The rotation detection device, wherein each of the plurality of contact surfaces and the inner peripheral surface are smoothly connected in the rotation axis direction. 2. The rotation detecting device according to claim 1, wherein the annular member has slopes provided between each of the plurality of contact surfaces and the inner peripheral surface. 3. The rotation detecting device according to claim 2, wherein the slope includes at least one of a plane portion and a curved portion. 4. The rotation detecting device according to claim 1, wherein the width of the inner peripheral surface in the direction of the rotation axis is longer than the width of the scale member in the direction of the rotation axis. 4. The rotation detection device according to claim 1, wherein the width of the inner peripheral surface in the direction of the rotation axis is shorter than the width of the scale member in the direction of the rotation axis. further comprising a fixing member to which the detection means is attached;
6. The rotation detecting device according to claim 1, wherein the inner peripheral surface of the annular member is a bearing portion that engages with the fixed member. The inner peripheral portion of the annular member has a plurality of recesses that are recessed radially outward of the annular member from the inscribed circle of the plurality of contact surfaces ,
7. The scale member according to claim 1, wherein said scale member is attached to said inner peripheral portion of said annular member in a state of being bent into a ring shape and bent inside said plurality of concave portions. 1. The rotation detection device according to claim 1. an imaging optical system;
A lens device comprising the rotation detection device according to any one of claims 1 to 7. a lens device according to claim 8;
an imaging device that photoelectrically converts an optical image formed through the lens device;
and a camera body that holds the imaging element. 10. The imaging apparatus according to claim 9, wherein the lens device is detachable from the camera body.

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