Motor and apparatus using the same

The present invention relates to a motor and an apparatus using the same.

A friction drive type ultrasonic motor (vibration-wave motor) using a deformation based on a piezoelectric effect of a piezoelectric element as a driving source has a generative force larger than that of an electromagnetic motor and can drive a driven part without providing a deceleration mechanism. Moreover, it drives the driven part using friction, thus enabling drive with large holding force and excellent in quietness. Japanese Patent Laid-Open No. 2015-136205 discloses a linear vibration type motor that includes a vibrator having an elastic member being provided with two pressure contact parts and a piezoelectric element, and a contacted member contacting the pressure contact parts pressed by a pressing spring. Furthermore, Japanese Patent No. 3825643 discloses a vibration-wave motor including a configuration different from that of the motor disclosed in Japanese Patent Laid-Open No. 2015-136205.

In Japanese Patent Laid-Open No. 2015-136205, rolling balls, which are fitted in V-shape grooves provided on both of a moving plate integrated with a moving part and a fixed unit cover member in a driving direction, receive reaction force of pressing force by the pressing spring and guide a movement while rolling, thus reducing a driving load. However, as the positions of the moving plate and the unit cover member, which sandwich the rolling balls, are determined through a plurality of members, a gap to allow the rolling balls to fall off from the V-shape grooves may be generated due to dimensional accuracy of the intervening members. Increasing a diameter of each of the rolling balls to prevent falling of the rolling balls enlarges the apparatus.

Additionally, in Japanese Patent No. 3825643, a vibrator is pressed to a rail by a V-shape plate spring, and reaction force of pressing force is received by a rotating member abutting against a lower surface of the rail through a fixing plate supporting the plate spring. However, the rotating member rotates, but driving resistance due to friction is applied to a rotating shaft while the rotating shaft receives the reaction force. In this configuration, as friction torque acting on the rotating shaft decreases according to a ratio with respect to an outside diameter, the apparatus enlarges to reduce the driving resistance.

In view of the problem, an object of the present invention is to provide a motor capable of suppressing falling of rolling members and capable of miniaturizing.

A motor according to one aspect of the present invention includes a vibrator, a pressing member that presses the vibrator onto a contacting member in contact with the vibrator, a moving member that moves integrally with the vibrator, a guide member that includes a surface parallel to a contact surface of the contacting member with the vibrator and that guides a movement of the moving member, and at least three or more rolling members that are sandwiched between the moving member and the guide member. The vibrator and the contacting member move relatively by vibrations that occur in the vibrator. The moving member includes at least two or more first groove shapes that separately formed on the same straight line parallel to a moving direction of the vibrator, and a second groove shape that formed in parallel with the moving direction to separate from the first groove shapes in a direction orthogonal to the moving direction. The guide member includes a first guide part that is opposite to the first groove shapes and that includes a surface having a predetermined angle with respect to the surface parallel to the contact surface, and a second guide part that is opposite to the second groove shape and that is parallel to the surface parallel to the contact surface. The rolling members are sandwiched between each of the first groove shapes and the first guide part and between the second groove shape and the second guide part. On a rear side of a surface of the guide member where the first and second guide parts are formed, the moving member includes a plurality of regulating parts that regulate a movement of the guide member to the rear side. When the guide member abuts against the plurality of regulating parts, part of each of the rolling balls is positioned inside each of the first groove shapes or the second groove shape.

An apparatus according to another aspect of the present invention includes a motor, and a member that drives by driving force from the motor. The motor includes a vibrator, a pressing member that presses the vibrator onto a contacting member in contact with the vibrator, a moving member that moves integrally with the vibrator, a guide member that includes a surface parallel to a contact surface of the contacting member with the vibrator and that guides a movement of the moving member, and at least three or more rolling members that are sandwiched between the moving member and the guide member. The vibrator and the contacting member move relatively by vibrations that occur in the vibrator. The moving member includes at least two or more first groove shapes that separately formed on the same straight line parallel to a moving direction of the vibrator, and a second groove shape that formed in parallel with the moving direction to separate from the first groove shapes in a direction orthogonal to the moving direction. The guide member includes a first guide part that is opposite to the first groove shapes and that includes a surface having a predetermined angle with respect to the surface parallel to the contact surface, and a second guide part that is opposite to the second groove shape and that is parallel to the surface parallel to the contact surface. The rolling members are sandwiched between each of the first groove shapes and the first guide part and between the second groove shape and the second guide part. On a rear side of a surface of the guide member where the first and second guide parts are formed, the moving member includes a plurality of regulating parts that regulate a movement of the guide member to the rear side. When the guide member abuts against the plurality of regulating parts, part of each of the rolling balls is positioned inside each of the first groove shapes or the second groove shape.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

FIG. 1 is a sectional view of an image pickup apparatus including a vibration-wave motor unit according to an embodiment of the present invention.

FIGS. 2A and 2B are a plan view and a side view of a vibrator according to a first example.

FIGS. 3A and 3B are perspective views of a vibration-wave motor unit according to the first example.

FIG. 4 is an exploded perspective view of the vibration-wave motor unit according to the first example.

FIG. 5A to 5C are a plan view and sectional views of the vibration-wave motor unit according to the first example.

FIGS. 6A to 6E are explanatory diagrams of a degree of freedom in motion of the vibrator according to the first example.

FIG. 7 is an explanatory diagram of a relation between a pressing plate and a moving member according to the first example.

FIGS. 8A and 8B are perspective views of a straight guide member according to the first example.

FIGS. 9A to 9D are explanatory diagrams of the straight guide member according to the first example.

FIGS. 10A and 10B are explanatory diagrams of assembly of the straight guide member according to the first example.

FIGS. 11A to 11D are perspective views of a lens driving unit according to the first example.

FIGS. 12A and 12B are perspective views of a vibration-wave motor unit according to a second example.

FIG. 13 is an exploded perspective view of the vibration-wave motor unit according to the second example.

FIG. 14A to 14C are a plan view and sectional views of the vibration-wave motor unit according to the second example.

FIGS. 15A to 15C are explanatory diagrams of a degree of freedom of a vibrator according to the second example.

FIG. 16 is an explanatory diagram of a relation between a pressing plate and a moving member according to the second example.

FIG. 17 is a perspective view of a straight guide member according to the second example.

FIGS. 18A and 18B are explanatory diagrams of a coupling part of the vibration-wave motor unit and a lens unit according to the second example.

Referring now to the accompanying drawings, a detailed description will be given of embodiments of the present invention. Those elements in each figure, which are corresponding elements, will be designated by the same reference numerals, and a description thereof will be omitted.

FIG. 1 is a sectional view of an image pickup apparatus (optical apparatus) including a vibration-wave motor unit (a vibration-wave motor or an ultrasonic motor unit, hereinafter, referred to as “motor unit”) 1000 according to an embodiment of the present invention. The image pickup apparatus according to this embodiment includes an image pickup lens unit 2000 and a camera body 3000 . Inside the image pickup lens unit 2000 , the motor unit 1000 and a focusing lens unit 4000 , which is attached to the motor unit 1000 , are provided. Inside the camera body 3000 , an image pickup element 5000 is provided. The motor unit 1000 moves the focusing lens 4000 along an optical axis O while capturing an image. An object image is imaged at a position of the image pickup element 5000 , and the image pickup element 5000 generates a focused image. In this embodiment, the image pickup apparatus includes the motor unit 1000 , but the present invention is not limited to this. For example, the motor unit 1000 may be mounted on the other optical apparatus, such as a lens unit, or may be mounted on an apparatus different from an optical apparatus. Moreover, in this embodiment, the image pickup lens unit 2000 and the camera body 3000 are integrally configured, but the present invention is not limited to this. The image pickup lens unit 2000 may be detachably attached to the camera body 3000 . In other words, an apparatus in the present invention is an apparatus including a vibration-wave motor explained in each example, and a member that drives by driving force from the vibration-wave motor.

First Example

Referring to FIGS. 2A and 2B , a description will be given of a vibrator 2 included in a motor unit 1000 A according to this example. FIGS. 2A and 2B are a plan view and a side view of the vibrator 2 . FIGS. 2A and 2B are respectively a plan view and a side view of the vibrator 2 . The vibrator 2 includes driving protrusions 2 a and 2 b , and fixed arm parts 2 c and 2 d . To the vibrator 2 , a vibrating plate (elastic plate) 3 and a piezoelectric element 4 are fixed with the adhesive. The piezoelectric element 4 excites ultrasonic vibration by being applied with two-phase high frequency voltages, and an elliptical motion on an x-y plane illustrated in FIG. 2B is energized at ends of the driving protrusions 2 a and 2 b . In this state, when a friction member comes into frictional contact the driving protrusions 2 a and 2 b , the vibrator 2 and the friction member relatively move. In this example, a rectangular area A×B, which faces a friction member (contacting member) 7 and includes the driving protrusions 2 a and 2 b , is a driving force generation area (facing area). Moreover, a plane C, which is orthogonal to the rectangular area A×B and the x-axis, and symmetrically divides the rectangular area A×B, is a front/rear symmetric plane, and a plane D, which is orthogonal to the rectangular area A×B and the z-axis, and symmetrically divides the rectangular area A×B, is a left/right symmetric plane. The front/rear symmetric plane C includes a direction orthogonal to both of a moving direction of a moving part and a pressing direction of pressers, as described below, and the pressing direction of the pressers. Furthermore, the left/right symmetric plane D includes the moving direction of the moving part and the pressing direction of the pressers.

Referring to FIGS. 3A, 3B, 4, and 5A to 5C , a description will be given of a configuration of the motor unit 1000 A. FIGS. 3A and 3B are perspective views of the motor unit 1000 A. FIG. 3A is a perspective view as seen form a top side, and FIG. 3B is a perspective view as seen from a bottom side. FIG. 4 is an exploded perspective view of the motor unit 1000 A. FIGS. 5A to 5 C are a plan view and sectional views of the motor unit 1000 A. FIG. 5A is a plan view, and FIGS. 5B and 5C are sectional views taken along an x-x line and a z-z line of FIG. 5A , respectively.

A base member 5 is fixed to a fixing member (not illustrated) by the screws, and fixes a friction member 7 using the screws. The friction member 7 comes into frictional contact with the driving protrusions 2 a and 2 b of the vibrator 2 by pressing force of tension coil springs 10 . A flexible substrate 6 is mechanically and electrically connected to the piezoelectric element 4 by the anisotropic conductive paste, and applies the two-phase high frequency voltages to the piezoelectric element 4 . A vibrator holding frame 8 is integrated with the vibrator 2 by fixing the fixed arm parts 2 c and 2 d with the adhesive. A pressing intermediary member 9 includes a felt 9 a that contacts the vibrator 2 , and a high rigid plate 9 b , such as the metal, that receives the pressing force of the tension coil springs 10 . The felt 9 a transmits the pressing force of the tension coil springs 10 to the vibrator 2 without preventing the vibrations energized in the vibrator 2 . The four tension coil springs (pressing members) 10 are disposed around the vibrator 2 , and generates the pressing force in a negative direction (pressing direction) of the y-axis as pressers in this example. A pressing plate 11 is biased by the tension coil springs 10 . The pressing plate 11 also includes a spherical protrusion 11 a that abuts against the pressing intermediately member 9 on an intersection line of the front/rear symmetric plane C and the left/right symmetric plane D of the vibrator 2 . A coupling sheet metal 12 is fixed to the vibrator holding frame 8 by the screws. A guide member 13 is fixed to the base member 5 by the screws through a fixed sheet metal 16 to be parallel to a contact surface of the friction member 7 with the driving protrusions 2 a and 2 b . A moving member 14 is biased by the tension coil springs 10 . Rolling balls (rolling members) 19 x , 19 y and 19 z each are sandwiched between the guide member 13 and the moving member 14 , and receives the pressing force of the tension coil springs 10 . An integrated spring 15 is a tension coil spring that biases the vibrator holding frame 8 and the moving member 14 through the coupling sheet metal 12 to be integrated in the x-axis direction. In this example, a moving part, which includes the vibrator 2 , the vibrator holding frame 8 , the pressing intermediary member 9 , the tension coil springs 10 , the pressing plate 11 , the coupling sheet metal 12 , and the moving member 14 , relatively moves along the x-axis with respect to the friction member 7 .

Next, referring to FIGS. 6A to 6E , a description will be given of a degree of freedom in motion of the vibrator 2 according to this example. FIGS. 6A to 6E are explanatory diagrams of the degree of freedom in motion of the vibrator 2 . In FIGS. 6A to 6E , components of the motor unit 1000 A unnecessary for the explanation are omitted. FIG. 6A illustrates the vibrator holding frame 8 and the moving member 14 , which are integrated by biasing force of the integrated spring 15 through the coupling sheet metal 12 . The integrated spring 15 is hooked between a hook part 8 a provided on the vibrator holding frame 8 and a hook part 14 b provided on the moving member 14 . A reference ball 17 is sandwiched between a conical hole part 12 a formed on the coupling sheet metal 12 and a conical hole part 14 a formed on the moving member 14 . A rolling ball 18 is sandwiched between a V-shape groove 8 b formed on the vibrator holding frame 8 and a plane part 14 c formed on the moving member 14 . Sandwiching the rolling ball 18 between the V-shape groove 8 b and the plane part 14 c restricts rotation of the vibrator holding frame 8 and the moving member 14 in the rotational direction (yaw direction) around the y-axis centering the reference ball 17 .

FIG. 6B illustrates a sectional view of the motor unit 1000 A cut on a plane containing setting centers of the integrated spring 15 , the reference ball 17 , and the rolling ball 18 . Arrows A to C each represent force for acting on the vibrator holding frame 8 . The force represented by the arrow A is force for biasing the vibrator holding frame 8 by the integrated spring 15 to rotate the vibrator holding frame 8 around the reference ball 17 . The force represented by the arrow B is force for acting on the V-shape groove 8 b from the plane part 14 c through the rolling ball 18 . Sandwiching the rolling ball 18 between the V-shape groove 8 b and the plane part 14 c restricts the rotation of the vibrator holding frame 8 and the moving member 14 around the reference ball 17 , that is, the rotation of the vibrator holding frame 8 in the yaw direction is restricted. Then, moments of the forces A and B around the reference ball 17 balances.

The force C is force for acting on the vibrator holding frame 8 through the coupling sheet metal 12 , balancing with resultant force of the forces A and B as illustrated in FIG. 6C . Thus, the degree of freedom in motion in the x-axis direction (x-axis translation direction) and the z-axis direction (z-axis translation direction) of the vibrator holding frame 8 is restricted. Moreover, as the reference ball 17 is sandwiched between the conical hole part 12 a and the conical hole part 14 a , the degree of freedom in motion in the y-axis direction (y-axis translation direction) of the vibrator holding frame 8 is also restricted.

As described above, in this example, the motion of the vibrator holding frame 8 , which is integrated with the vibrator 2 , to the moving member 14 has two degrees of freedom in the rotational direction (roll direction) around the x-axis and the rotational direction (pitch direction) around the z-axis. In this example, as the vibrator 2 has the two degrees of freedom in motion in the roll direction and in the pitch direction, the driving protrusions 2 a and 2 b of the vibrator 2 can abut against the friction member 7 certainly. Additionally, the forces A to C, which restrict the degree of freedom in motion of the vibrator 2 , balance within one plane, thus not generating unbalance of unnecessary force to the driving protrusions 2 a and 2 b.

FIGS. 6D and 6E respectively illustrate states where the vibrator holding frame 8 rotates in the roll direction and in the pitch direction around the reference ball 17 . As illustrated in FIGS. 6D and 6E , the rotation in the roll direction moves the driving protrusions 2 a and 2 b up and down along the y-axis direction, and the rotation in the pitch direction can correspond to differences between positions in the y-axis direction.

FIG. 7 is an explanatory diagram of a relation between the pressing plate 11 and the moving member 14 . The four tension coil springs 10 engage each of spring hook parts of the pressing plate 11 and the moving member 14 . As a distance in the y-axis direction between the pressing plate 11 and the moving member 14 is determined by unillustrated components of the motor unit 1000 A, the four tension coil springs 10 biases the pressing plate 11 and the moving member 14 . The four tension coil springs 10 are symmetrically disposed at equal intervals from the spherical protrusion 11 a and have the same specification. However, biasing force of each tension coil spring at a predetermined length is not necessarily the same due to production tolerance, and error in a position of each of spring hook parts of the pressing plate 11 and the moving member 14 is also caused due to production precision in a single part and production error of intervening parts. In this example, the pressing plate 11 is abutted against the pressing intermediary member 9 by the spherical protrusion 11 a , and has the degree of freedom in motion (tilt) in the roll direction and the pitch direction with the spherical protrusion 11 a as a fulcrum. In other words, the pressing part 11 can tilt in the roll direction and the pitch direction with the spherical protrusion 11 a as a fulcrum. Accordingly, the pressing force of the four tension coil springs 10 acting on the driving protrusions 2 a and 2 b from the spherical protrusion 11 a through the pressing intermediary member 9 each are adjusted optimally with respect to the production tolerance.

Moreover, the pressing plate 11 has the degree of freedom in motion in the roll and pitch directions relative to the vibrator holding frame 8 including the pressing intermediary member 9 , an attitude of the pressing plate 11 with respect to the moving member 14 is adjusted to be an optimum state regardless of a tilt of the vibrator holding frame 8 and a change of the tilt. Thus, the pressing force of each of the four tension coil springs 10 acting on the driving protrusions 2 a and 2 b from the spherical protrusion 11 a through the pressing intermediary member 9 becomes stable without variations. In addition, although the distance in the y-axis direction between the pressing plate 11 and the moving member 14 may change, a spring constant of the tension coil springs 10 can be smaller than that of a plate springs, and this is advantageous to stabilization of the pressing force.

Besides, as a protrusion 11 b provided on the pressing plate 11 engages a groove part 8 c as illustrated in FIG. 6B formed on the vibrator holding frame 8 , the pressing plate 11 and the moving member 14 are integrated in the x-axis direction through the vibrator holding frame 8 . Accordingly, the pressing force of the tension coil springs 10 becomes stable without changing a positional relation among the tension coil springs 10 , the pressing plate 11 , and the moving member 14 while the moving part moves along the x-axis.

FIGS. 8A and 8B are perspective views of a straight guide member including the guide member 13 , the moving member 14 , and the rolling balls 19 x , 19 y and 19 z , which are sandwiched between both members. FIGS. 9A to 9D are explanatory diagrams of the straight guide member. On the moving member 14 , straight guide grooves 14 x , 14 y an 14 z , which respectively engage the rolling balls 19 x , 19 y and 19 z , are formed to be parallel to the x-axis direction (moving direction of the moving part). The straight guide grooves (first groove shapes) 14 x and 14 y are tandemly formed along the x-axis, that is, are separately formed on the same straight line parallel to the x-axis. The straight guide groove (second groove shape) 14 z is also formed along the x-axis to separate from the straight holding grooves 14 x and 14 y in the z-axis direction. When the rolling balls 19 x , 19 y and 19 z rolls, the moving member 14 smoothly moves along the x-axis with respect to the guide member 13 while receiving the pressing force of the tension coil springs 10 .

FIG. 9A illustrates a state where the guide member 13 and the moving member 14 abut against the rolling balls 19 x , 19 y and 19 z . FIG. 9B also illustrates a sectional view of a plane including the rolling balls 19 y and 19 z in the state of FIG. 9A . On part of each of the straight guide grooves 14 x , 14 y and 14 z , a surface having an opening angle of 60 degrees is formed to be engageable with each rolling ball. On the guide member 13 , a guide wall (first guide part) 13 x - y is continuously formed along the x-axis to be opposite to the straight guide grooves 14 x and 14 y and to engage the rolling balls 19 x and 19 y . The guide wall 13 x - y has an opening angle of 120 degrees to be engageable with each rolling ball. Additionally, on the guide member 13 , a guide plane part (second guide part) 13 z is formed along the x-axis in parallel with the x-z plane to be opposite to the straight guide groove 14 z and to engage the rolling ball 19 z . In this example, the surface having the opening angle of 60 degrees is formed on part of each straight guide groove, but the present invention is not limited to this. For example, a plane having a predetermined angle with respect to the x-z plane may be formed along the x-axis on part of each straight guide groove, and the whole straight guide groove may be formed as a V-shape groove having a predetermined opening angle. Furthermore, in this example, the guide wall 13 x - y has the opening angle of 120 degrees, but the present invention is not limited to this. For example, the guide wall 13 x - y may be formed along the x-axis to have a predetermined angle with respect to the x-z plane as long as being engageable with each rolling ball.

On the guide member 13 , plane parts (abutting parts) 13 v and 13 w are formed. The moving member 14 , as described above, includes the four spring hook parts (engaging parts) that each engage the tension coil springs 10 . In the state of FIG. 9A , a restriction part 14 v , which is part of each of two of the four spring hook parts, is provided to have an interval “a” to the plane part 13 v in the y-axis direction. On the moving member 14 , two stoppers (regulating parts) 14 w are also provided to have an interval “a” to the plane part 13 w in the y-axis direction in the state of FIG. 9A .

FIG. 9C illustrates a state where the guide member 13 abuts against the moving member 14 in the y-axis direction, that is, a state where the plane parts 13 v and 13 w respectively engage the two restriction parts 14 v and the two stoppers 14 w . FIG. 9D also illustrates a sectional view of a plane including the rolling ball 19 z in the state of FIG. 9C . In FIG. 9C , the rolling balls 19 x , 19 y and 19 z respectively engage the straight guide grooves 14 x , 14 y and 14 z , but do not contact the guide member 13 . Moreover, in FIG. 9D , the rolling balls 19 x , 19 y and 19 z contact the guide member 13 , but do not contact the moving member 14 . As illustrated in FIG. 9D , the rolling ball 19 z overlaps with the straight guide groove 14 z by an interval “b” in the z-axis direction when contacting the guide member 13 , thus being prevented from falling from the straight guide groove 14 z . In addition, the rolling balls 19 x and 19 y each overlap with the straight guide grooves 14 x and 14 y by an interval “b” in the z-axis direction, thus being prevented from falling the straight guide groove 14 x and 14 y.

As mentioned above, providing the plurality of the restriction parts 14 v and the stoppers 14 w , which respectively engage the plane parts 13 v and 13 w , can prevent the rolling balls 19 x , 19 y and 19 z from falling. In particular, the restriction parts 14 v and the stoppers 14 w may be provided so that the interval “a” is shorter than an interval c from a setting surface 14 e of the moving member 14 to a position where each rolling member engage the corresponding straight guide groove. In this example, the restricting parts 14 v and the stoppers 14 w are provided so that the each rolling ball overlaps with the moving member 14 by the interval “b” when the guide member 13 moves in the y-axis direction, that is, so that part of each rolling ball is positioned inside each straight guide groove. In this example, the motor unit 1000 A according to this example includes the three rolling balls 19 x , 19 y and 19 z , but the present invention is not limited to this. For example, the three or more rolling balls may be provided, and the guide part of the guide member 13 and the straight guide groove of the moving member 14 may be formed according to the rolling balls. However, when the three or more rolling balls are provided, some rolling balls fail to engage the guide part and the straight guide groove due to production error of the rolling balls and the straight guide grooves, and thus the moving member 14 hardly moves highly accurately. Accordingly, to move the moving member 14 highly accurately, the number of the rolling balls is preferably three.

Moreover, in this example, as illustrated in FIG. 8B , the spring hook parts of the moving member 14 are disposed in a projection plane in the y-axis direction of the guide member 13 . Specifically, the spring hook parts are disposed to sandwich the straight guide grooves 14 x , 14 y and 14 z , the guide wall 13 x - y , and the guide plane part 13 z . Such an arrangement can utilize a space (space on a rear side of a surface provided with the guide wall 13 x - y and the guide plane part 13 z ) on a positive side of the y-axis of the guide member 13 effectively. The conical hole part 14 a engaging the reference ball 17 , the hook part 14 b engaging the integrated spring 15 , and an interlocking part 14 d described later are also disposed in the projection plane in the y-axis direction of the guide member 13 . In particular, each member is disposed to sandwich the straight guide grooves 14 x , 14 y and 14 z , the guide wall 13 x - y , and the guide plane part 13 z . Utilizing the space on the positive side of the y-axis of the guide member 13 can miniaturize the motor unit 1000 A.

In this example, with the above configuration, it is impossible to assemble the guide member 13 , the moving member 14 and the rolling balls 19 x , 19 y and 19 z in the y-axis direction. Thus, in this example, when the rolling balls 19 x , 19 y and 19 z on the straight guide grooves 14 x , 14 y and 14 z of the moving member 14 are inserted in the guide member 13 by sliding in a direction of an arrow S, a state of FIG. 10A or 10B becomes a built-in state illustrated in FIG. 8A .

FIG. 11A is a perspective view of a lens driving unit in a state where the motor unit 1000 A is attached. FIG. 11B is a perspective view of the lens driving unit in a state where the motor unit 1000 A is not attached. FIG. 11C is a diagram illustrating a coupling part of the motor unit 1000 A and a lens unit 300 . FIG. 11D is a sectional view of the coupling part. The lens unit 300 is supported to be movable along the optical axis (x-axis) by a configuration of a bar and a sleeve. Guide bars 301 and 302 are formed to be parallel to the x-axis, being supported by an unillustrated member. An interlocking member 303 is integrated with the lens unit 300 in the optical axis direction through an interlocking biasing spring 304 , and rotating force in a direction of an arrow R is applied to the coupling member 303 . As illustrated in FIG. 11D , on the interlocking part 14 d provided on the moving member 14 , a groove shape having an opening angle of 60 degrees is formed. By the rotating force in the direction of the arrow R illustrated in FIG. 11B , a spherical interlocking part 303 a provided on the interlocking member 303 engages the groove shape formed on the interlocking part 14 d , and driving force of the motor unit 1000 A is transmitted to the lens unit 300 through the interlocking member 303 . The rotating force in the direction of the arrow R of the interlocking member 303 is also received by the guide member 13 through the rolling balls 19 x , 19 y and 19 z . Additionally, positional error in the y-axis direction between the motor unit 1000 A and the lens unit 300 is absorbed by the rotation of the interlocking member 303 in the direction of the arrow R, and positional error in the z-axis direction between them is absorbed by moving the engagement position of the groove shape formed on the interlocking part 14 d and the spherical interlocking part 303 a in the z-axis direction. Thus, even when error in production exits, the motor unit 1000 A enables the lens unit 300 to smoothly and certainly move along the optical axis.

Second Example

Referring to FIGS. 12A, 12B, 13, and 14A to 14C , a description will be given of a configuration of a vibration-wave motor unit (an ultrasonic motor unit, hereinafter, referred to as “motor unit”) 1000 B according to this example. FIGS. 12A and 12B are perspective views of the motor 1000 B. FIG. 12A is a perspective view as seen form a top side, and FIG. 12B is a perspective view as seen from a bottom side. FIG. 13 is an exploded perspective view of the motor unit 1000 B. FIGS. 14A to 14C are a plan view and sectional views of the motor unit 1000 B. FIG. 14A is a plan view, and FIGS. 14B and 14C are sectional views taken along an x-x line and a z-z line of FIG. 14A , respectively.

The vibrator 2 included in the motor unit 1000 B according to this example is identical with the vibrator 2 of the first example. A base member 105 is fixed to a fixing member (not illustrated) by the screws, and fixes a friction member 107 using the screws. The friction member 107 comes into frictional contact with the driving protrusions 2 a and 2 b by pressing force of tension coil springs 110 . As well as the first example, a flexible substrate 106 is mechanically and electrically connected to the piezoelectric element 4 of the vibrator 2 by an anisotropic conductive paste, and applies the two-phase high frequency voltages to the piezoelectric element 4 . A vibrator holding frame 108 is integrated with the vibrator 2 by fixing the fixed arm parts 2 c and 2 d with the adhesive. A pressing intermediary member 109 includes a felt 109 a that contacts the vibrator 2 , and a high rigid plate 109 b , such as the metal, that receives the pressing force of the tension coil springs 110 . The felt 109 a transmits the pressing force of the tension coil springs 110 to the vibrator 2 without preventing the vibrations energized in the vibrator 2 . The four tension coil springs (pressing members) 110 are disposed around the vibrator 2 , and, as described above, generate the pressing force as pressers in this example. A pressing plate 111 is biased by the tension coil springs 110 . The pressing plate 111 also includes two spherical protrusions 111 a that abuts against the pressing intermediately member 109 and that are equally positioned in the y-axis direction. The two spherical protrusions 111 a are provided to be symmetric with respect to the left/right symmetric plane D in the front/rear symmetric plane C of the vibrator 2 . A moving member outer frame 112 is integrated with a moving member 114 by the screws. A guide member 113 is fixed to the base member 105 by the screws through a fixed sheet metal 116 to be parallel to a contact surface of the friction member 107 with the driving protrusions 2 a and 2 b . The moving member 114 is biased by the tension coil springs 110 . Rolling balls (rolling members) 119 x , 119 y and 119 z each are sandwiched between the guide member 113 and the moving member 114 , and receives the pressing force of the tension coil springs 110 . In this example, a moving part, which includes the vibrator 2 , the vibrator holding frame 108 , the pressing intermediary member 109 , the tension coil springs 110 , the pressing plate 111 , the moving member outer frame 112 , and the moving member 114 , relatively moves along the x-axis with respect to the friction member 107 .

Next, referring to FIGS. 15A to 15C , a description will be given of a degree of freedom in motion of the vibrator 2 according to this example. FIGS. 15A to 15C are explanatory diagrams of the degree of freedom in motion of the vibrator 2 . In FIGS. 15A to 15C , components of the motor unit 1000 B unnecessary for the explanation are omitted. FIG. 15A illustrates the moving member outer frame 112 and the moving member 114 , which are integrated with the vibrator holding frame 108 . FIG. 15B illustrates a sectional view of the configuration illustrated in FIG. 15A cut on a plane containing a reference bar 117 , and a biased bar 118 . FIG. 15C illustrates a sectional view of the configuration illustrated in FIG. 15A cut on the left/right symmetric plane D of the vibrator 2 .

An integrated spring 115 is a plate spring fixed to a spring attachment part 112 b provided on the moving member outer part 112 , and biases a plane part 108 b formed on the vibrator holding frame 108 in a direction of an arrow D through the biased bar 118 . Moreover, a plane part 108 a formed on the vibrator holding frame 108 receives reaction force in a direction of an arrow E in balance with the biasing force in the direction of the arrow D through the reference bar 117 sandwiched between the plane part 108 a and a plane part 112 a formed on the moving member outer part 112 . Thus, the vibrator 108 and the moving part outer frame 112 are integrated in the x-axis direction by the biasing force of the integrated spring 115 through the reference bar 117 and the biased bar 118 . Additionally, sandwiching the reference bar 117 between the plane part 112 a and the plane part 108 a also restricts the rotation of the vibrator holding part 108 in the yaw direction. Furthermore, the vibrator holding frame 108 fits within the moving part outer frame 112 in the z-axis direction, thus restricting the rotation of the vibrator holding frame 108 in the z-axis direction (z-axis translation direction) and the roll direction.

As described above, the motion of the vibrator holding frame 108 , which is integrated with the vibrator 2 with respect to the moving member 114 , has two degrees of freedom in the y-axis direction (y-axis translation direction) and the pitch direction. In this example, the vibrator 2 has the two degrees of freedom in the y-axis direction and the pitch direction, thus enabling the driving protrusions 2 a and 2 b of the vibrator 2 to certainly abut against the friction member 107 . In addition, the driving protrusions 2 a and 2 b , and the friction member 107 move by the rotation of the reference bar 117 and the biased bar 118 , and thus can decrease friction of the motion. Furthermore, the biasing force in the direction of the arrow D and the reaction force in the direction of the arrow E balance within one plane, thus not generating unbalance of unnecessary force to the driving protrusions 2 a and 2 b.

FIG. 16 is an explanatory diagram of a relation between the pressing plate 111 and the moving member 114 . The four tension coil springs 110 engage each of spring hook parts of the pressing plate 111 and the moving member 114 . As a distance in the y-axis direction between the pressing plate 111 and the moving member 114 is determined by unillustrated components of the motor unit 1000 B, the four tension coil springs 110 bias the pressing plate 111 and the moving member 114 . In this example, the two spherical protrusions 111 a , which are equally positioned in the y-axis direction, abut against the pressing intermediary member 109 , and the pressing plate 111 has the degree of freedom in motion (tilt) in the pitch direction with the two spherical protrusions 111 a as a fulcrum. In other words, the pressing part 111 can tilt in the pitch direction with the two spherical protrusions 111 a as a fulcrum. Accordingly, the pressing force of the four tension coil springs 110 acting on the driving protrusions 2 a and 2 b from the two spherical protrusions 111 a through the pressing intermediary member 109 each are adjusted optimally.

Moreover, as the pressing plate 111 has the degree of freedom in motion in the pitch direction relative to the vibrator holding frame 108 including the pressing intermediary member 109 , an attitude of the pressing plate 111 with respect to the moving member 114 is adjusted to be an optimum state regardless of a tilt of the vibrator holding frame 108 and a change of the tilt. In addition, although the distance in the y-axis direction between the pressing plate 111 and the moving member 114 may change, a spring constant of the tension coil springs 110 can be smaller than that of a plate spring, and this is advantageous to stabilization of the pressing force.

Besides, as a protrusion 111 b provided on the pressing plate 111 engages a groove part 108 c as illustrated in FIG. 15B formed on the vibrator holding frame 108 , the pressing plate 111 and the moving member 114 are integrated in the x-axis direction through the vibrator holding frame 108 . Accordingly, the pressing force of the tension coil springs 110 becomes stable without changing a positional relation among the tension coil springs 110 , the pressing plate 111 , and the moving member 114 while the motor unit 1000 B moves along the x-axis.

FIG. 17 is a perspective view of a straight guide member including the guide member 113 , the moving member 114 , and the rolling balls 119 x , 119 y and 119 z , which are sandwiched between both members. A relation among the guide member 113 , straight guide grooves 114 x , 114 y and 114 z formed on the moving member 114 , and the rolling balls 119 x , 119 y and 119 z are the same as that in the first example, and thus the explanation thereof is omitted. On the guide member 113 , plane parts (abutting parts) 113 v and 113 w are formed. The moving member 114 , as described above, includes the four spring hook parts (engaging parts) that each engage the tension coil springs 110 . As with the first example, a restriction part 114 v , which is part of each of two of the four hook spring hook parts, is provided to have an interval “a” to the plane part 113 v in the y-axis direction in the state where the guide member 113 and the moving member 114 abut against each rolling balls. On the moving member 114 , two stoppers (regulation parts) 114 w are also provided to have an interval “a” to the plane part 113 w in the y-axis direction in the state where the guide member 113 and the moving member 114 abut against each rolling ball. The above configuration prevents the rolling balls 119 x , 119 y and 119 z from falling. Moreover, in this example, as with the first example, the hook spring parts of the moving member 114 are disposed in a projection plane in the y-axis direction of the guide member 113 . Such an arrangement can utilize a space on a positive side of the y-axis of the guide member 113 effectively, and can miniaturize the motor unit 1000 B.

The motor unit 1000 B according to this example is served as part of a lens driving unit to drive a lens unit along the optical axis. FIGS. 18B and 18B are explanatory diagrams of a coupling part of the motor unit 1000 B and the lens unit. As with the first example, by rotational force in the direction of the arrow R in FIG. 11B , a spherical interlocking part 112 c provided on the moving part outer frame 112 engages an interlocking groove 401 a that is formed on an interlocking member 401 provided on the lens unit and has an opening angle of 60 degrees. Accordingly, the driving force from the motor unit 1000 B is transmitted to the interlocking member 401 through the moving member outer frame 112 . Moreover, as the rotating force in the direction of the arrow R is received by the guide member 113 through the moving member 114 , which is integrated with the moving member outer frame 112 , and the rolling balls 119 x , 119 y and 119 z , unnecessary force is not transmitted to the vibrator holding frame 108 .

An expression “each member exists in a plane” in each example may be interpreted that at least part of the member intersects the surface.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No. 2016-091380, filed on Apr. 28, 2016, which is hereby incorporated by reference herein in its entirety.