JPH0428012Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a reflective optical rotary encoder, and in particular to an optical rotary encoder in which a code plate is fixed at a predetermined rotational position in a click-stop manner. Regarding rotary encoders.

[Conventional technology]

For example, the optical rotary encoder was developed in 1983.
As described in Japanese Patent No. 170020, it is used as a mode signal generator, etc. in a video editing device.

Such optical rotary encoders include a so-called transmission type in which a light emitting element and a light receiving element are arranged facing each other on both sides of a code plate having a transmission part and a blocking part, and a code plate having a reflection part and a non-reflection part. A so-called reflective type is known in which a light emitting element and a light receiving element are arranged concentrated on one side of the frame, but the latter reflective type is superior in terms of thinning.

This reflective optical rotary encoder includes a code plate in which reflective parts and non-reflective parts are alternately formed in the circumferential direction, an operating shaft for rotating the code plate, and a printed circuit board on the bearing side of the operating shaft. The light emitted from the light emitting element is intermittently received by the light receiving element according to the rotation of the code plate, so that the rotation angle of the code plate changes. Corresponding electrical signals are now output.

By the way, in this type of reflective optical rotary encoder, the rotary plate caulked and fixed to the operating shaft has a click function in addition to the function as the code plate, and the code plate can be clicked to a desired rotation position for various modes. There is a demand for locking at the top. This click mechanism consists of a cam section consisting of a groove or hole, a ball that engages and disengages from the cam section, and an elastic body such as a spring or leaf spring that biases the ball toward the cam section. The ball was formed on the surface of the rotary plate, and the ball was held by a support member having an elastic body fixed to the bearing side of the operating shaft.

[Problems to be solved by the invention] However, in the conventional structure mentioned above,
Since the balls and elastic bodies are placed in the space formed between the code plate (rotary plate) and the printed circuit board, there is a natural limit to reducing the axial dimension of the operating shaft. There was a problem in that the advantage of thinness, which is a characteristic of encoders, could not be fully utilized.

Therefore, an object of the present invention is to solve the problems of the prior art described above and to provide an optical rotary encoder that can be made thinner.

[Means for solving problems]

In order to achieve the above object, the present invention includes an operating shaft rotatably supported on a bearing, a rotary plate having a cord part fixed to the operating shaft and consisting of a reflective part and a non-reflective part, and a rotary plate on the bearing side. a printed circuit board fixed to the board and mounted with a light receiving/emitting element facing at least the cord part, and a click mechanism is formed by a plurality of cam parts provided on the rotary plate and a sphere that can be engaged with and detached from the cam part. In the optical rotary encoder, a support plate having a holding part is fixed to the bearing side, and the holding part is made to face the cam part of the rotary plate through an opening formed in the printed circuit board, It is characterized in that the spherical body is interposed between the leaf spring locked to the holding portion and the rotary plate.

[Effect]

As mentioned above, the holding part of the support plate fixed to the bearing side is made to face the cam part of the rotating plate through the opening made in the printed circuit board, and the leaf spring is locked to this holding part, so that the ball is attached to the cam part. When configured to be elastically biased in the direction, the holding portion and the printed circuit board partially overlap, so that the optical rotary encoder can be made thinner by the thickness of the overlapping printed circuit board.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Fig. 1 is a longitudinal sectional view of an optical rotary encoder according to an embodiment of the present invention, and Fig. 2 is an exploded perspective view thereof. In these figures, 1 is an inner shaft, 2 is an outer shaft, and 3 is a first code board, 4 is the second code board,
5 is a bearing, 6 is a support plate, 7 is a printed circuit board, and 8 is a case.

The inner shaft 1 is rotatably inserted into the hollow outer shaft 2, and both are prevented from falling off by a washer 9 and an E-ring 10. The outer shaft 2 is a bearing 5
It is inserted into the outer shaft 2 and is prevented from coming off by an E-ring 11. Furthermore, a mounting plate 12 is provided on the upper part of the outer shaft 2.
is fixed by a washer 13 and a nut 14.

A metal support plate 6 is caulked and fixed to the bearing 5, and a pair of holding portions 15 are bent in the lateral direction of the support plate 6. This holding part 15 includes a regulating piece 15a having a hole and a regulating piece 15a having a hole.
It consists of arm portions 15b facing each other via a, and both ends of a leaf spring 16 are locked to these arm portions 15b. This leaf spring 16 urges a ball 17 inserted into a hole in the regulating piece 15a toward a click plate, which will be described later.These leaf springs 16, balls 17, and click plate form a click mechanism. There is. On the other hand, a pair of stoppers 18 and four locking claws 19 are bent and formed at both longitudinal ends of the support plate 6, and these stoppers 18 and four locking claws 19 are inserted into the insertion hole 7a of the printed circuit board 7. By doing so, the support plate 6 and the printed circuit board 7 are positioned and integrated as shown in FIG. A pair of rectangular openings 20 are bored in this printed circuit board 7, and the aforementioned holding portion 15 of the support plate 6 is inserted through these openings 20 so that a part thereof reaches the lower surface side of the printed circuit board 7. . Further, the printed circuit board 7 is placed and fixed on the upper end of the case 8 by a plurality of screws 21, and a plurality of light receiving and emitting elements 22 constituting a photoreflector are mounted on the lower surface of the printed circuit board 7. First and second code plates 3 and 4, which will be described later, are formed by these light receiving and emitting elements 22.
The rotation angle is now detected.

A disk-shaped metal plate 23 is caulked and fixed to the lower end of the inner shaft 1, and the first code plate 3 is fixed to the outer periphery of the metal plate 23. As shown in the exploded perspective view of FIG. 4, the first code plate 3 has a base plate 24 made of a synthetic resin material with high light absorption, and a thin aluminum plate with high reflection efficiency formed into an annular comb-like shape. and a reflective plate 25, both of which are connected to the base plate 2.
They are integrated by applying heat to the protrusions 24b of No. 4. In the integrated state, the comb-teeth portion of the reflecting plate 25 is the reflecting part 25a, and each reflecting part 2 is
The base plate 24 exposed between 5a is a non-reflective part 24a.
These are arranged alternately in the circumferential direction of the first code plate 3.

FIG. 5 explains the caulking process for attaching the metal plate 23 to the inner shaft 1. The oval-shaped hole 23a formed in the center of the metal plate 23 is inserted into the slot 1a of the inner shaft 1 (indicated by the broken line in the figure). After inserting the
The metal plate 23 is caulked and fixed to the inner shaft 1 by making the thickness of the slotted portion 1a uneven in the direction shown by the solid line. Then, before and after this caulking process, the first code plate 3 is fixed to the outer periphery of the metal plate 23 by the heat of the protrusion 24b of the base plate 24, so that the first code plate 3 is fixed to the outer periphery of the metal plate 23. It is fixed to the inner shaft 1 via 23. In this way, since the highly rigid metal plate 23 is used in the caulking portion as a means for fixing the first code plate 3 to the inner shaft 1, the thickness of the first code plate 3 can be reduced.

On the other hand, a click plate 26 made of a hard metal plate is caulked and fixed to the lower end of the outer shaft 2, and a second code plate 4 is fixed to the outer periphery of the click plate 26. As shown in the exploded perspective view of FIG.
The code plate 4 is composed of a base plate 27 made of a synthetic resin material with high light absorption, and a reflector plate 28 made of a thin aluminum plate with high reflection efficiency. They are integrated by applying heat to the protrusions 27 (not shown). In this case, through holes 27a or notches 2 are formed at predetermined intervals in the circumferential direction of the base plate 27.
A part of the reflection plate 28 is exposed through the reflection plate 7b, and this exposed part becomes a reflection part 28a, and the base plate 27 around the reflection part 28a becomes a non-reflection part 27c. Note that a part of the through hole 27a or notch 27b is not blocked by the reflective plate 28 and is a slit, and the non-reflective part 24a and the reflective part 25a of the first cord 3 mentioned above It is arranged to face some of the light receiving and emitting elements 22 via the light emitting and receiving elements 22.

A plurality of short connecting pieces 29 and one long engaging piece 30 are respectively formed to protrude radially from the outer periphery of the click plate 26.
When the protrusion 27d of the base plate 27 is exposed to heat on the engaging piece 30, the click plate 26 and the second code plate 4 are integrated. Further, a plurality of cam portions 26a consisting of holes or grooves are formed in the circumferential direction on this click plate 26, and as described above, the click plate 26 is rotated by the leaf spring 16.
A click mechanism is formed by the balls 17, which are elastically biased in six directions, engaging and disengaging from these cam portions 26a.

FIG. 7 explains the caulking process for attaching the click plate 26 to the outer shaft 2. The mounting hole 26b formed in the center of the click plate 26 is connected to the stepped portion 2a of the outer shaft 2 (the part indicated by the broken line in the figure). After inserting into
The click plate 26 is caulked and fixed to the outer shaft 2 by making the thickness of the stepped portion 2a uneven in the direction shown by the solid line. Then, before and after this caulking process, heat is applied to the connecting piece 29 and the engaging piece 30 that protrude from the click plate 26 of the second code plate 4, so that the second code plate 4 is attached to the click plate 4. The outer shaft 2 is fixed to the outer shaft 2 through the outer shaft 2. In this case, the tip of the engagement piece 30
When the tip of this engaging piece 30 comes into contact with both stoppers 18 of the support plate 6, the click plate 26 and the second code plate 4 fixed thereto are The rotation angle is now regulated. Note that a rubber ring 31 is fitted to the tip of the engagement piece 30, and the rubber ring 3
1 functions as a sound deadening material when in contact with the stopper 18.

The optical rotary encoder according to this embodiment is constructed as described above, and its operation will be explained next.

When the slit of the second code plate 4 is in a position facing the light receiving/emitting element 22 that detects the first code plate 3, when the inner shaft 1 is rotated and the first code plate 3 is rotated, the above-mentioned light receiving/emitting The light emitted from the element 22 reaches the first code plate 3 through the slit, is absorbed by the non-reflective portion 24a, and is reflected only by the reflective portion 25a. Therefore, the light receiving/emitting element 22 outputs a pulse signal corresponding to the rotation angle of the first code plate 3.

Furthermore, when the second code plate 4 is rotated by rotating the outer shaft 2, the light emitted from the light receiving/emitting element 22 is reflected by the reflecting portion 28a, and the reflected light is received by the light receiving/emitting element 22. A pulse signal corresponding to the rotation angle of the second code plate 4 is obtained. in this case,
The click plate 26 rotates integrally with the second code plate 4, and during the rotation, the ball 17 hits the cam portion 26a.
The rotational position of the second code plate 4 is confirmed by a click sensation.

In the above embodiment, a holding part 15 is provided on the support plate 6 fixed to the bearing 5, and the holding part 15 is inserted into the opening 20 of the printed circuit board 7 to open the click board 2.
6 are facing each other, so that the holding part 15 and the opening 20
The axial dimension of the operating shafts (inner shaft 1 and outer shaft 2) can be reduced by the amount of overlap, that is, the board thickness dimension of the printed circuit board 7. Further, the printed circuit board 7 is fixed to the bearing 5 via the support plate 6 by fitting the locking claws 19 of the support plate 6 into the insertion hole 7a, so the printed circuit board 7 is placed on the bearing 5 side. The installation work is simplified, the relative position between the printed circuit board 7 and the support plate 6 is maintained with high precision, and the light emitting/receiving element 22 for detecting the second code plate 4 and the second code plate 4 are connected to each other. The positional accuracy of the stopper 18 for regulating the rotation range is improved.

[Effect of idea]

As described in detail above, the present invention has the holding part of the support plate fixed to the bearing side facing the cam part of the rotary plate through the opening made in the printed circuit board, and the leaf spring is locked to this holding part. Since the ball is elastically biased toward the cam portion, the axial dimension of the operating shaft can be reduced by an amount equivalent to the thickness of the printed circuit board, and a thin optical rotary encoder can be provided. It becomes possible.

[Brief explanation of drawings]

The figures are all for explaining an optical rotary encoder according to an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view showing the overall configuration of the optical rotary encoder;
Figure 2 is an exploded perspective view, Figure 3 is a bottom view showing how the printed circuit board and support plate are attached, and Figure 4 is the exploded perspective view.
Figure 5 is an explanatory diagram of the process of caulking and fixing the metal plate to the inner shaft, Figure 6 is an exploded perspective view of the second code plate and click plate, Figure 7 is an exploded perspective view of the second code plate and metal plate. FIG. 6 is an explanatory diagram of the process of caulking and fixing the click plate to the outer shaft. DESCRIPTION OF SYMBOLS 1... Inner shaft, 2... Outer shaft, 3... First code plate, 4... Second code plate, 5... Bearing, 6...
Support plate, 7... Printed circuit board, 7a... Insertion hole,
8... Case, 15... Holding part, 15a... Regulating piece, 15b... Arm part, 16... Leaf spring, 17...
Ball, 18... Stopper, 19... Locking claw, 2
0...Opening, 22...Receiving/emitting element, 23...Metal plate, 23a...Hole, 24...Base plate, 24a...
...Non-reflective part, 24b...Protrusion, 25...Reflector,
25a...Reflector, 26...Click board, 26a
...Cam part, 26b...Mounting hole, 27...Base plate, 27a...Through hole, 27b...Notch, 27c
...Non-reflective portion, 27d...Protrusion, 28...Reflector, 28a...Reflector, 29...Connection piece, 30...
...Engagement piece, 31...Rubber ring.

Claims (1)

[Scope of utility model registration request] an operating shaft rotatably supported by a bearing; a rotary plate fixed to the operating shaft and having a cord portion consisting of a reflective portion and a non-reflective portion; and a light receiving/emitting light fixed to the bearing side and opposing at least the cord portion. In the optical rotary encoder, the optical rotary encoder is provided with a printed circuit board on which an element is mounted, and a click mechanism is formed by a plurality of cam parts provided on the rotary plate and a sphere that can be engaged with and detached from the cam part. At the same time, a support plate having a rotation plate is fixed to the bearing side, and the holding part is made to face a cam part of the rotary plate through an opening formed in the printed circuit board, and a plate spring latched to the holding part and the rotation An optical rotary encoder characterized in that the sphere is interposed between the plate and the plate.