The present invention relates to a driving unit, a lens driving device, a camera module, and a camera-mounted device.
Conventionally, a camera module mounted on a thin camera-mounted device such as a smartphone is known. Such a camera module is known to include a lens driving device having a zoom function for enlarging or downsizing a subject image.
For example, PTL 1 discloses a configuration including a fixed lens on which light from a subject is incident, two movable lenses on which the light deflected by the fixed lens is incident, and a lens driving part for moving the two movable lenses in the direction of the optical axis.
In the meantime, using an ultrasonic-motor type driving unit has been considered from a viewpoint of miniaturization of a camera-mounted device. In the ultrasonic-motor type driving unit, an active element having a resonant portion and a passive element relatively moving with respect to the active element are in contact with each other in a biased state, and the both elements slide against each other during driving.
Hence, when the positional relationship between the active element and the passive element in a contact portion of the both elements is displaced, a driving condition of the driving unit might vary in accordance with a contact position between the active element and the passive element. That is, the stability of driving performance of the driving unit (ultrasonic motor) decreases due to the displaced positional relationship between the active element and the passive element in the contact portion between the both elements.
An object of the present invention is to provide a driving unit, a lens driving device, a camera module, and a camera-mounted device each capable of improving the stability of driving performance of an ultrasonic motor.
A driving unit according to the present invention is a driving unit for generating a thrust to move a movable part in a predetermined direction, the driving unit including:
A lens driving device according to the present invention includes:
A camera module according to the present invention includes:
A camera-mounted device according to the present invention is a camera-mounted device that is an information apparatus or a transporting apparatus, the camera-mounted device including:
According to the present invention, it is possible to improve the stability of driving performance of an ultrasonic motor.
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
As illustrated in
In describing the structure of camera module 1 of the present embodiment, an orthogonal coordinate system (X, Y, Z) is used. The same orthogonal coordinate system (X, Y, Z) is also used for illustration of below-mentioned figures. Camera module 1 is mounted such that the horizontal direction is the X-direction, the vertical direction is the Y-direction, and the front-rear direction is the Z-direction, for example, during actually capturing an image with a camera-mounted device. Light from a subject is incident from the −side (minus side) in the Z-direction, and is deflected and guided to the +side (plus side) in the Y-direction. By reducing the thickness of camera module 1 in the Z-direction, it is possible to reduce the thickness of the camera-mounted device.
As illustrated in
Drive control part 100 includes a Central Processing Unit (CPU), Read Only Memory (ROM), Random Access Memory (RAM), or the like. The CPU reads a program suited to processing contents out of the ROM, develops the program in the RAM, and integrally controls an operation of lens driving part 60 in cooperation with the developed program. Thus, drive control part 100 drives, in the Y-direction (direction of optical axis), second lens unit 32 and third lens unit 33 to be described later of lens part 30 housed in housing 10. As a result, camera module 1 performs stepless optical zoom and autofocus. Housing 10, support shaft 50, lens driving part 60, position detection part 70, and drive control part 100 correspond to the “lens driving device” of the present invention.
Further, as illustrated in
Mirror 22 according to the present embodiment has two rotation axes (not illustrated) extending in the X-direction and the Z-direction. In reflection driving part 20, mirror 22 is rotated about the rotation axes under the control of reflection drive control part 23. Thus, camera module 1 has a shake correction function (Optical Image Stabilization (OIS) function) for optically correcting a shake (vibration) that occurs during capturing an image, so as to reduce image irregularities.
Reflected light L2 incident on housing 10 is output to image capturing part 40 via lens part 30 housed in housing 10.
Image capturing part 40 is disposed on the outer surface of housing 10 on the +side in the Y-direction (placement portion 112B of second wall 112 to be described later), and is configured to allow reflected light L2 to be incident thereon through lens part 30. Image capturing part 40 includes an image capturing device, a board, and the like (neither is illustrated).
The image capturing device is composed of, for example, a Charge-Coupled Device (CCD) image sensor, a Complementary Metal Oxide Semiconductor (CMOS) image sensor, or the like. The image capturing device is mounted on the board and electrically connected to the interconnections on the board via bonding wires. The image capturing device captures a subject image imaged by lens part 30 and outputs an electrical signal corresponding to the subject image.
Further, a printed wiring board (not illustrated) is electrically connected to the board of image capturing part 40. The power supply to the image capturing device and the output of the electrical signal of the subject image imaged by the image capturing device are performed via the printed wiring board. The electrical signal is output to image capturing control part 200 provided in the camera-mounted device. Image capturing control part 200 includes a CPU, a ROM, a RAM, and the like, and processes image information obtained by camera module 1. Image capturing control part 200 may be mounted on the camera-mounted device, or may also be built in camera module 1.
As illustrated in
Side wall portion 11 is a wall portion made of, for example, resin and having a portion opening on the −side in the Y-direction, and has first walls 111, second wall 112, third walls 113, and fourth walls 114 (see also
A pair of first walls 111 is configured to extend in the Y-direction, and are provided on both sides in the X-direction. Of the pair of first walls 111, the inner surface of first wall 111 of housing 10 on the +side in the X-direction, placement portions 111A on which an ultrasonic motor to be described later is disposed are provided. On one of first walls 111 situated on the +side in the X-direction, placement portions 111A are provided on both sides of the central portion in the Y-direction.
Further, as illustrated in
Further, portions to be engaged (hereinafter, each referred to as engaged portion) 111B with which positioning portions 121 of bottom wall portion 12 are engaged are formed in the bottom surface of first wall 111 (the surface on the −side in the Z-direction).
As illustrated in
Further, guide supporting portions 112C and opening portion 112D are formed in placement portion 112B of second wall 112. In the present embodiment, guide supporting portions 112C are holes for supporting guide shafts 81 and 82 to be described later, and are formed on the −side of opening portion 112D in placement portion 112B in the X-direction. Two guide supporting portions 112C are formed side by side in the Z-direction. Opening portion 112D is an opening in which fourth lens unit 34 of lens part 30 is fitted, and is formed in placement portion 112B at the central portion in the X-direction.
As illustrated in
Further, supporting portions 113B for supporting support shafts 50 are formed in the top surfaces of the pair of third walls 113 (the surfaces on the +side in the Z-direction). Guide supporting portion 113C for supporting guide shafts 81 and 82 to be described later is formed in the vicinity of a central portion of one of the pair of third walls 113 in the Z-direction.
Guide supporting portion 113C is a long hole configured to have a length in the Z-direction corresponding to the placement range of two guide supporting portions 112C in second wall 112 described above. Guide supporting portion 113C is capable of supporting guide shafts 81 and 82 supported respectively by two guide supporting portions 112C in second wall 112.
As illustrated in
As illustrated in
Positioning portions 121 are formed on the both lateral ends of bottom wall portion 12 in the X-direction. Positioning portions 121 are formed to protrude from the both lateral ends of bottom wall portion 12, and are to be engaged with engaged portions 111B of first wall 111 described above. Thus, it is possible to position bottom wall portion 12 in the Y-direction.
Further, as illustrated in
Further, grooves (not illustrated) in which bent portions 122 are fitted are formed in portions of housing 10 corresponding to bent portions 122. Bent portions 122 are fitted in the grooves, and accordingly, bottom wall portion 12 is fixed to housing 10.
Further, a plurality of half punches 123 aligned in the Y-direction are formed in a surface of bottom wall portion 12. Half punches 123 are formed in bottom wall portion 12 over the X-direction. In the present embodiment, a total of six half punches 123 are formed.
Such formation of half punches 123 can improve the strength of the bottom wall portion of housing 10.
As illustrated in
First lens unit 31 is disposed on the most upstream side in the incident direction of reflected light L2 (direction toward the +side in the Y-direction) and has body portion 31A and supported portion 31B. Body portion 31A is a portion for holding the lens and is fixed between the pair of third walls 113 in housing 10. Supported portion 31B is a portion supported by support shaft 50 and is provided to protrude from both sides in the X-direction in body portion 31A.
The side surfaces of main body portion 31A are configured to be curved so as to be convex at central portions in the Z-direction, for example. The side surfaces of third wall 113 on the side of main body portion 31A are shaped, for example, to conform the side surfaces of main body portion 31A, and are configured such that the curved portions of main body portion 31A are fitted thereto. Thus, first lens unit 31 is fixed between the pair of third walls 113.
Second lens unit 32 is disposed on the downstream side of first lens unit 31 in the incidence direction, and includes main body portion 32A and supported portions 32B. Third lens unit 33 is disposed on the downstream side of second lens unit 32 in the incidence direction, and includes main body portion 33A and supported portions 33B. Second lens unit 32 corresponds to the “first movable part” of the present invention, and third lens unit 33 corresponds to the “second movable part” of the present invention.
Main body portions 32A and 33A hold a lens through which the light having been passed through first lens unit 31 is passed. Supported portions 32B and 33B are portions movably supported by support shafts 50 and are respectively provided on both sides of main body portions 32A and 33A in the X-direction.
The lens included in main body portion 32A of second lens unit 32 corresponds to the “first movable lens” of the present invention. The lens included in main body portion 33A of third lens unit 33 corresponds to the “second movable lens” of the present invention.
Fourth lens unit 34 is disposed on the most downstream side in the incidence direction, and is configured to include a lens. Fourth lens unit 34 is supported by support shafts 50 at a position adjacent to second wall 112 of housing 10. As illustrated in
The lenses in first to fourth lens units 31 to 34 may be assembled to housing 10 when the lens driving device is manufactured, or may be assembled to housing 10 when camera module 1 is manufactured from the lens driving device.
Protruding portion 34A has a size making it possible to be fitted into opening portion 112D in second wall 112. By this protruding portion 34A fitted into opening portion 112D, fourth lens unit 34 is fixed to housing 10.
As illustrated in
Lens driving parts 60 are provided to correspond respectively to second lens unit 32 and third lens unit 33, and each of the lens driving parts moves corresponding one of second lens unit 32 and third lens unit 33 independently under the control of drive control part 100 described above. Lens driving part 60 corresponds to the “driving unit” of the present invention.
Lens driving parts 60 are disposed in the region of one of fourth walls 114 on the +side in the X-direction surrounded by first wall 111, second wall 112, and third wall 113. That is, as illustrated in
In the present embodiment, two lens driving parts 60 are provided side by side in the Y-direction. One of lens driving parts 60 on the −side in the Y-direction drives second lens unit 32 in the Y-direction, and the other one of lens driving parts 60 on the +side in the Y-direction drives third lens unit 33 in the Y-direction. That is, lens driving part 60 on the −side in the Y-direction corresponds to the “first driving unit” of the present invention, and lens driving part 60 on the +side in the Y-direction corresponds to the “second driving unit” of the present invention.
Each of lens driving parts 60 has substantially the same configuration in the present embodiment. Hence, in the following description, unless otherwise stated, only lens driving part 60 corresponding to second lens unit 32 will be described, and lens driving part 60 corresponding to third lens unit 33 will not be described. Further, lens driving parts 60 are symmetrically disposed in the Y-direction in the present embodiment. Hence, the relationship between the +side and the −side in the Y-direction in lens driving part 60 corresponding to third lens unit 33 is reverse with respect to the relationship between the +side and the −side in the Y-direction in lens driving part 60 corresponding to second lens unit 32.
Lens driving part 60 includes frame 61, connecting part 62, interposition part 63, ultrasonic motor 64, and guide part 80.
Frame 61 is connected via connecting part 62 to one of supported portions 32B and 33B of second lens unit 32 and third lens unit 33.
Frame 61 is configured to be movable in the direction of optical axis O by guide part guiding the movement in the direction of optical axis O (Y-direction). Movement of frame 61 in the direction of optical axis O causes second lens unit 32 or third lens unit 33 connected to frame 61 via connecting part 62 to also move along support shafts 50.
As illustrated in
First portion 611A is a portion forming the top surface of frame 61 (surface on the +side in the Z-direction), and is configured to extend in the direction of the optical axis (Y-direction). First portion 611A is provided to cover guide part 80 from the +side in the Z-direction.
Further, connecting part 62 is provided on the surface on the +side of first portion 611A in the Z-direction. As illustrated in
As illustrated in
Shaft hole 611E extending through in the Y-direction is formed in second portion 611B. Shaft hole 611E is formed at a position corresponding to first guide shaft 81 to be described later, and allows first guide shaft 81 to be passed therethrough.
Shaft engaging portion 611F is formed in the end portion of second portion 611B on the −side in the Z-direction. Shaft engaging portion 611F is formed at a position where engagement with below-described second guide shaft 82 is possible, and is engaged with second guide shaft 82 from the +side in the Z-direction.
Third portion 611C is a portion that extends to the −side in the Z-direction from the end portion of first portion 611A on the +side in the Y-direction (the other end of first portion 611A), and supports second guide shaft 82. More particularly, third portion 611C extends to a position such that the end portion on the −side in the Z-direction is spaced apart from second guide shaft 82 by a predetermined distance.
Shaft hole 611G extending through in the Y-direction is formed in third portion 611C. Shaft hole 611G is formed at a position corresponding to first guide shaft 81, and allows first guide shaft 81 to be passed therethrough.
Fourth portion 611D is a portion extending from the end portion of first portion 611A on the +side in the X-direction. Fourth portion 611D is formed over entire first portion 611A in the Y-direction, and is disposed to cover guide part 80 from the +side in the X-direction.
As illustrated in
Guide part 80 includes first guide shaft 81 and second guide shaft 82, both of which extend in the direction of the optical axis (Y-direction). The first and the second guide shafts are disposed to be spaced apart from each other and cooperate to support both of two frames 61 such that the frames are movable in the direction of the optical axis. First guide shaft 81 and second guide shaft 82 are formed of, for example, stainless steel or the like, and are supported by guide supporting portions (not illustrated) of second wall 112 and third wall 113 of housing 10 at opposite end sides of the optical axis (opposite end sides in the X-direction).
First guide shaft 81 is a guide shaft for guiding the movement of each of frames 61 by supporting second portion 611B and third portion 611C of guided portion 611 of frame 61.
Second guide shaft 82 is a guide shaft disposed parallel to first guide shaft 81 on the −side (fourth wall 114 side) of first guide shaft 81 in the Z-direction, and for guiding the movement of frame 61 by supporting (being engaged with) second portion 611B of guided portion 611 of frame 61. In addition, first guide shaft 81 and second guide shaft 82 are disposed at substantially the same position in the X-direction as one of above-described support shafts (see
Second guide shaft 82 is supported by bearing portion 114A provided on fourth wall 114. Bearing portion 114A is provided between two frames 61 to protrude from fourth wall 114 to the +side in the Z-direction, and is disposed in the vicinity of the central portion of second guide shaft 82 in the Y-direction. Second guide shaft 82 is adhesively fixed to bearing portion 114A. Further, bearing portion 114A is disposed in a range including center 82A of second guide shaft 82 in the X-direction (direction between opposite ends with respect to the optical axis) (see
Further, bearing portion 114A is provided at a position where contact with second portion 611B of frame 61 is possible. Therefore, when frame 61 is moved to the +side in the Y-direction, second portion 611B and bearing portion 114A of frame 61 are brought into contact with each other (see dashed lines in
As illustrated in
Recessed portion 612A is formed in the end portion of magnet holding portion 612 on the −side in the Z-direction, and magnet part 614 is held in the recessed portion. Further, position detection part 70 is provided on a portion of housing 10 facing magnet part 614. Position detection part 70 is, for example, a Hall element for detecting the position of frame 61 in the Y-direction, and detects the position of magnet part 614 based on a predetermined reference position.
Thus, for example, as illustrated in
Further, as illustrated in
Two protrusions D1 and D2 are provided on the surface of fourth portion 611D of frame 61 on the +side in the X-direction.
Two protrusions D1 and D2 protrude from the surface of fourth portion 611D and are disposed side by side in the Y-direction. In the present embodiment, protrusion D1 is provided in the vicinity of the end portion of fourth portion 611D on the −side in the Y-direction, and protrusion D2 is provided in the vicinity of the central portion of fourth portion 611D in the Y-direction.
Holes A1 and A2 through which two protrusions D1 and D2 of fourth portion 611D of frame 61 are passed are formed in interposition part 63 (supporting member 632 to be described later). Passing protrusions D1 and D2 through holes A1 and A2 enables the positioning of interposition part 63. Interposition part 63 will be described later in detail.
As illustrated in
Ultrasonic motor 64 on the −side in the Y-direction corresponds to the “first ultrasonic motor” of the present invention, and ultrasonic motor 64 on the +side in the Y-direction corresponds to the “second ultrasonic motor” of the present invention.
Resonant portion 641 is formed of, for example, a conductive material and resonates with the vibration of piezoelectric elements 642 to convert a vibrational motion into a linear motion of frame 61. Specifically, resonant portion 641 vibrates in an inclination direction inclined with respect to the direction of the optical axis (Y-direction) based on the vibration of piezoelectric elements 642 so as to press interposition part 63 (plate-shaped members 631 to be described below). Accordingly, a thrust to move frame 61 via interposition part 63 in the direction of the optical axis is generated. Resonant portion 641 is disposed to be clamped between two plate-shaped members 631 of interposition part 63. As illustrated in
Body portion 641A is a portion that is clamped by piezoelectric elements 642 and is a portion that is connected to all of two oscillators 641B, protruding portion 641C, and energization portion 641D.
Two oscillators 641B extend in the Y-direction from both sides of body portion 641A in the Z-direction. Two oscillators 641B have symmetrical shapes, and their respective free end portions make contact with plate-shaped members 631 of interposition part 63. The two oscillators 641B respectively correspond to the “first oscillator” and the “second oscillator” of the present invention.
Protruding portion 641C extends to the +side in the Y-direction from body portion 641A. Energization portion 641D extends to the side opposite to protruding portion 641C (the −side in the Y-direction) from body portion 641A.
Each of piezoelectric elements 642 is, for example, a vibration element formed of a ceramic material in a plate shape, and generates a vibration by application of a high-frequency voltage. Two piezoelectric elements 642 are provided to clamp body portion 641A of resonant portion 641 in the X-direction, respectively.
First electrode 643 includes clamping portion 643A for clamping resonant portion 641 and piezoelectric elements 642, and electrode portion 643B to which a voltage is applied. Via clamping portion 643A for clamping piezoelectric elements 642 and the like, first electrode 643 applies a voltage to piezoelectric elements 642. Second electrode 644 is electrically connected to energization portion 641D of resonant portion 641. First electrode 643 and second electrode 644 make contact with the above-described board of board placement portion 111C, inside housing 10.
Two piezoelectric elements 642 are bonded to body portion 641A of resonant portion 641 and are held in between by first electrode 643, so that these are electrically connected to one another. For example, one side of a power supply path is connected to first electrode 643, and the other side is connected to second electrode 644. A voltage is applied to piezoelectric elements 642, and a vibration is thus generated.
Resonant portion 641 has at least two resonant frequencies, and deforms in behaviors different between the resonant frequencies. In other words, the entire shape of resonant portion 641 is set such that resonant portion 641 deforms in behaviors different between the two resonant frequencies. The different behaviors mean behaviors of moving frame 61 to the +side and to the −side in the Y-direction via interposition part 63.
As illustrated in
When plate-shaped members 631 are pressed in the directions of arrows A by the tip ends of oscillators 641B, reaction forces returning on the oscillators 641B sides are generated at plate-shaped members 631. In other words, interposition part 63 generates a reaction force in a direction from the outside of the pair of plate-shaped members 631 toward the inside based on the contact between oscillators 641B and the pair of plate-shaped members 631.
By the reaction force of interposition part 63 with respect to the press of oscillators 641B, the friction generated between oscillators 641B and plate-shaped members 631 causes a thrust in the Y-direction in interposition part 63. Accordingly, the thrust for movement in the Y-direction is applied to frame 61 to be bonded to interposition part 63 (see arrows B). As a result, second lens unit 32 or third lens unit 33 connected to frame 61 is moved in the Y-direction.
Further, plate-shaped members 631 are configured to extend in the Y-direction as described later. When pressed against oscillators 641B, plate-shaped members 631 move in the Y-direction while making sliding contact with oscillators 641B. Therefore, plate-shaped members 631 are continuously pressed by oscillators 641B. Thus, frame 61 to be bonded to interposition part 63 can be moved continuously in the Y-direction. Note that, at a certain resonant frequency, the pressing directions of oscillators 641B are the directions of arrows A and the sliding direction of plate-shaped members 631 is the direction of arrows B, whereas at another resonance frequency, the pressing directions of oscillators 641B are the directions of arrows C and the sliding direction of plate-shaped members 631 is the direction of arrows D.
Such driving operation is performed by each of ultrasonic motors 64 provided on each of first walls 111 on both sides in the X-direction. That is, ultrasonic motors 64 respectively drive second lens unit 32 and third lens unit 33 independently in the direction of the optical axis.
Next, a detailed description will be given of interposition part 63.
As illustrated in
The pair of plate-shaped members 631 is a contacting part having a plane extending in the Y-direction (predetermined direction, the first direction) and is composed of, for example, a hard member made of a metal material such as titanium-copper, nickel-copper, or stainless steel.
The pair of plate-shaped members 631 is provided to clamp the pair of oscillators 641B composing resonant portion 641 of ultrasonic motor 64 from the +side and −side in the Z-direction (see
In the pair of plate-shaped members 631, the plane portions are disposed substantially in parallel in the X-direction and the Y-direction so that resonant portion 641 and the plane portions can be in contact with each other. In addition, the thickness of plate-shaped member 631 is preferably set in consideration of durability when sliding with resonant portion 641 and the size, weight, and the like of lens driving part 60. As illustrated in
A pair of axis portions 631A is a portion supported by supporting member 632 and is provided to protrude from opposite end portions of plate-shaped member 631 in the Y-direction. In the present embodiment, recesses are respectively formed in side surfaces of plate-shaped members 631 on the +side and the −side in the Y-direction, and, of the side wall portions including the recessed portions, the −side wall portions in the X-direction are designated as axis portions 631A. Further, an axis portion may be a protrusion from a side surface of a plate-shaped member, for example.
A pair of recessed portions 631B is a portion recessed from the side surface of plate-shaped member 631 on the −side in the X-direction toward the +side in the X-direction, and the recessed portions are respectively provided in the vicinity of the end portions of the side surface on the +side and the −side in the Y-direction.
Supporting member 632 is formed of, for example, a plate-shaped metal member and includes frame connecting part 632A, supporting portions 632B, and regulating parts 632C.
Frame connecting part 632A is configured in a rectangular shape and is disposed to be substantially in parallel in the Y-direction and the Z-direction. Frame connecting part 632A is connected to fourth portion 611D of frame 61 (see
Hole A1 is a portion through which protrusion D1 of fourth portion 611D of frame 61 is passed, and is provided in a substantially central portion of frame connecting part 632A. Hole A2 is a portion through which protrusion D2 of fourth portion 611D of frame 61 is passed, and is provided in the vicinity of the end portion of frame connecting part 632A on the +side in the Y-direction.
Note that hole A2 is configured to be wider in the Y-direction than hole A1. Thus, even when manufacturing tolerances or the like cause the displacement in the positional relationships between protrusions D1 and D2 and holes A1 and A2, respective protrusions D1 and D2 can be easily passed through holes A1 and A2 (see
Supporting portions 632B are portions that turnably (movably) support the pair of plate-shaped members 631. Supporting portions 632B are formed by, for example, bending the opposite end portions of the plate-shaped metal member (frame connecting part 632A) in the Y-direction to the +side in the X-direction. Supporting portions 632B are respectively provided on the opposite end portions of frame connecting part 632A in the Y-direction.
On opposite end portions of each supporting portion 632B in the Z-direction, engaged portions 632D for engagement with axis portions 631A of each plate-shaped member 631 are provided. Engaged portions 632D are configured to be recessed from the opposite end portions of each supporting portion 632B in the Z-direction, and are provided at positions corresponding to respective axis portions 631A of the pair of plate-shaped members 631.
As illustrated in
Note that, in order to prevent axis portions 631A from being disengaged from the inside, engaged portions 632D are preferably formed such that the recession amount with respect to the side surfaces of supporting portions 632B in the Z-direction is set to a depth level longer than the thickness of axis portions 631A (plate-shaped members 631), for example.
Regulating parts 632C are provided on the +side in the Z-direction (opposite side to side in contact with resonant portion 641) with respect to one of plate-shaped member 631 on the +side in the Z-direction. Regulating parts 632C are configured to extend from a side surface of frame connecting part 632A on the +side in the Z-direction to the +side in the Z-direction and then to extend to the +side in the X-direction. Two regulating parts 632C are provided side by side in the Y-direction, and are provided at positions displaced in the Y-direction from engaging portions 633C to be described later.
Within the extent covering the portion where plate-shaped member 631 is disposed, regulating parts 632C are spaced from plate-shaped member 631 to an extent allowing a collision with plate-shaped member 631 when plate-shaped member 631 moves too far toward the +side in the Z-direction.
Providing regulating parts 632C in such a manner enables regulating parts 632C to regulate excessive movement of plate-shaped member 631 on the +side in the Z-direction toward the +side in the Z-direction. Consequently, even in a situation where a force more than required is applied to plate-shaped member 631 by application of an external force such as when camera module 1 is dropped, the excessive movement of plate-shaped member 631 is regulated by regulating parts 632C, and thus, it is possible to suppress the coming off of plate-shaped member 631 from supporting member 632.
Further, magnet holding portion 612 of frame 61 is provided on interposition part 63 on the −side in the Z-direction. Magnet holding portion 612 is spaced from plate-shaped member 631 to an extent allowing the collision with plate-shaped member 631 when plate-shaped member 631 on the −side in the Z-direction moves too far toward the −side in the Z-direction. Magnet holding portion 612 corresponds to the “regulating part” of the present invention.
Providing magnet holding portion 612 in such a manner enables magnet holding portion 612 to regulate excessive movement of plate-shaped member 631 on the −side in the Z-direction toward the −side in the Z-direction. Consequently, even in a situation where a force more than required is applied to plate-shaped member 631 by application of an external force such as when camera module 1 is dropped, the excessive movement of plate-shaped member 631 is regulated by magnet holding portion 612, and thus, it is possible to suppress the coming off of plate-shaped member 631 from supporting member 632.
Further, at a position corresponding to engaging portions 633C to be described later, magnet holding portion 612 is preferably disposed away from engaging portions 633C to such an extent that magnet holding portion 612 is positioned outside of the moving range (vibration range) of engaging portions 633C. In the manner described above, it is possible to suppress the obstruction of a biasing action of engaging portions 633C with respect to plate-shaped members 631.
As illustrated in
Biasing main-body portion 633A forms a plane portion extending in the Y-direction and the Z-direction and is disposed at a position facing frame connecting part 632A, between resonant portion 641 and frame connecting part 632A of supporting member 632.
Biasing main-body portion 633A has long hole A3 and a pair of holes A4. Long hole A3 is provided in a center of biasing main-body portion 633A in the Y-direction and is configured to be longer in the Y-direction than holes A4. The pair of holes A4 is respectively provided at opposite end portions of biasing main-body portion 633A in the Y-direction.
Long hole A3 is located at a position corresponding to protrusion D1 when supporting member 632 is bonded to frame 61. Long hole A3 is configured such that the edge thereof is not in contact with protrusion D1.
Of the pair of holes A4, hole A4 situated on the +side in the Y-direction is located at a position corresponding to protrusion D2 when supporting member 632 is bonded to frame 61. Hole A4 configured such that the edge does not touch the protruding portion D2.
Arm portions 633B are provided to protrude in the Z-direction from the positions corresponding regions between long hole A3 and holes A4 in respective opposite end portions of biasing main-body portion 633A in the Z-direction, and connects between engaging portions 633C to be described later and biasing main-body portion 633A.
In particular, arm portions 633B protrude one by one from the opposite end portions of biasing main-body portion 633A in the Z-direction, in the portion corresponding the region between hole A4 on the −side in the Y-direction and long hole A3. Further, arm portions 633B protrude one by one from the opposite end portions of biasing main-body portion 633A in the Z-direction, in the portion corresponding the region between hole A4 on the +side in the Y-direction and long hole A3. That is, four arm portions 633B, two from the end portion on the +side and two from the end portion on the −side of biasing main-body portion 633A in the Z-direction, are provided in total.
By providing arm portions 633B in such a manner, when force to bend arm portions 633B is applied with respect to biasing main-body portion 633A, a restoring force (biasing force) is generated which allows portions of arm portions 633B to return to the biasing main-body portion 633A side.
Further, each arm portion 633B is configured to be tapered from a connecting portion in between with biasing main-body portion 633A, and hole A5 is formed in a central portion in the vicinity of the connecting portion of arm portion 633B in the Y-direction. The size of hole A5 can be appropriately adjusted in accordance with the biasing force required by biasing member 633 and the strength of arm portion 633B.
Further, biasing main-body portion 633A is provided with protruding portions 633D protruding from a position corresponding to long hole A3 and protruding portions 633E protruding from positions corresponding to the pair of holes A4.
Engaging portions 633C are portions in contact with a surface of plate-shaped member 631 on a side opposite to resonant portion 641 (outer side in the Z-direction), and extend from tip end portions of respective arm portions 633B (end portions in the Z-direction) to the +side in the X-direction.
In other words, two (a pair of) engaging portions 633C corresponding to two arm portions 633B at the end portion on the −side in the Y-direction are disposed to clamp the pair of plate-shaped members 631, and are thus engaged with and brought into contact with each of the pair of plate-shaped members 631. Further, two (a pair of) engaging portions 633C corresponding to two arm portions 633B at the end portion on the +side in the Y-direction are disposed to clamp the pair of plate-shaped members 631, and are thus engaged with and brought into contact with each of the pair of plate-shaped members 631. That is, two pairs of (a plurality of pairs of) engaging portions 633C are provided side by side in the Y-direction (see also
As illustrated in
Incidentally, a distance between the pair of plate-shaped members 631 is a distance allowing elastic deformations of respective arm portions 633B when the pair of plate-shaped members 631 is clamped by the pair of engaging portions 633C, and is appropriately set in accordance with the biasing force required by biasing member 633.
Thus, since plate-shaped members 631 are turnably supported by supporting member 632, when resonant portion 641 resonates, plate-shaped members 631 are moved in accordance with the resonance by being biased by biasing member 633. That is, biasing member 633 biases plate-shaped members 631 toward resonant portion 641 such that plate-shaped members 631 move in accordance with the resonance of resonant portion 641 and transmit the thrust to the movable part via supporting portions 632B.
Since plate-shaped members 631 extend in the Y-direction and are formed of a relatively hard member, biasing plate-shaped members 631 at the two positions by two pairs of engaging portions 633C enables application of a uniform biasing force to resonant portion 641 in the entire of plate-shaped members 631 in the Y-direction.
Thus, the biasing force can be equally applied in the Y-direction (moving direction of movable part) in the contact portion between an active element composed of resonant portion 641 and each plate-shaped member 631 (passive element) which relatively moves with respect to the active element. Consequently, the driving force of ultrasonic motor 64 can be stably transmitted to the movable part (second lens unit 32 or third lens unit 33) via interposition part 63.
Further, since plate-shaped members 631 are moved in accordance with the resonance of resonant portion 641, when plate-shaped members 631 and oscillators 641B slide against each other, the displacement of the positional relationship between them in the X-direction can be reduced. Consequently, the driving force of ultrasonic motor 64 can be further stably transmitted to the movable part. That is, in the present embodiment, it is possible to improve the stability of driving performance of ultrasonic motor 64.
Further, biasing member 633 is disposed in a state where the pair of engaging portions 633C clamp the pair of plate-shaped members 631 and without being fixed to supporting member 632 (frame connecting part 632A). In other words, biasing main-body portion 633A and arm portions 633B (connecting parts) of biasing member 633 are disposed in a free state with respect to supporting member 632 (member other than the pair of plate-shaped members 631).
Incidentally, the term “free state” herein refers to an unfixed state regardless of the presence or absence of contact with the member of interest (member other than the pair of plate-shaped members 631).
This enables operation of the entirety of biasing main-body portion 633A and arm portions 633B, which connects the pair of engaging portions 633C in the Z-direction, as a spring. For example, when the biasing main-body portion is disposed in a fixed manner to the supporting member, a biasing force is applied to the engaging portions by a portion not including the fixed portion of the biasing main-body portion.
Accordingly, for example, the manufacturing tolerances or the like cause the displacement of the fixed portion of the biasing main-body portion, and thereby, a length of each arm portion for generating a biasing force (including length from fixed position of biasing main-body portion to arm portion) also varies from a designed value. The designed value is, for example, a length of an arm portion when there is no displacement in the fixed portion of the biasing main-body portion. Therefore, in the pair of engaging portions, the biasing force adversely varies between the +side and −side in the Z-direction.
In contrast, in the present embodiment, since biasing main-body portion 633A and arm portions 633B are disposed in an unfixed manner with respect to supporting member 632, the length of each of biasing main-body portion 633A and arm portions 633B for generating a biasing force on engaging portions 633C does not vary.
As a result, the supposed biasing force can be applied to plate-shaped members 631. Further, the biasing force can be applied to plate-shaped members 631 equally on the +side and −side in the Z-direction, and thus, the accuracy of the biasing force by biasing member 633 can be improved, thereby further improving the driving performance of ultrasonic motor 64.
Further, since biasing main-body portion 633A and arm portions 633B are in the free state, operating the entirety of biasing main-body portion 633A and arm portions 633B as the spring allows the spring length to be lengthen as much as possible. As in the present embodiment, when plate-shaped members 631 that are relatively hard members are used, there is a need to increase the biasing force by biasing member 633 to some extent.
However, when the spring length is shortened while increasing the biasing force, a degree of stress applied to a spring part is increased. For example, in a case where the biasing main-body portion is fixed, the spring length in each engaging portion will be a length from the fixed position of the biasing main-body portion to the arm portion, which is extremely short compared to the entirety of the biasing main-body portion and the arm portions.
In contrast, in the present embodiment, the spring length of biasing member 633 can be lengthen as much as possible, so that the degree of stress applied to the entirety of biasing member 633 can be reduced. Consequently, it is possible to suppress a defect (e.g., damage) caused by the excessive stress applied to biasing member 633.
Further, in the X-direction (second direction perpendicular to direction along linear motion of frame 61 described above (Y-direction, the first direction) and perpendicular to biasing direction of biasing member 633), engaging portions 633C bias plate-shaped members 631 at positions between support points for plate-shaped members 631 in supporting member 632 (turning centers 631C of axis portions 631A) and contact points with plate-shaped members 631 in resonant portion 641.
In the manner described above, for example, it is possible to suppress the floating of axis portions 631A in plate-shaped members 631 in the case of biasing a position equivalent to the contacting points with plate-shaped members 631 in resonant portion 641.
As in the present embodiment, when plate-shaped members 631 that are relatively hard members are used, there is a need to increase the biasing force by biasing member 633 to some extent. Therefore, biasing a position where the axis portion 631A side does not float makes it easier to apply a strong biasing force.
Further, as illustrated in
Further, on the positions corresponding to engaging portions 633C in plate-shaped members 631, recessed portions 631B described above are formed. This makes it possible to suppress the displacement of biasing member 633 caused by contact of biasing member 633 with side surfaces of the plate-shaped members when biasing member 633 is assembled to the pair of plate-shaped members 631.
In the above-described embodiment, supporting member 632 turnably supports plate-shaped members 631, but the present invention is not limited to this case, and the supporting member may movably support the plate-shaped members to the +side and −side in the Z-direction, for example.
Further, in the above-described embodiment, supporting member 632 is configured to include engaged portions 632D with which axis portions 631A of plate-shaped members 631 are engaged, but the present invention is not limited to this case, and the supporting member may have any configuration as long as plate-shaped members 631 are movably supported.
In addition, in the above-described embodiment, biasing member 633 is provided between supporting member 632 and resonant portion 641, but the present invention is not limited to this case, and the biasing member may have any configuration and may be provided at any position as long as a plate-shaped member can follow a resonance of a resonant portion.
In the above-described embodiment, two pairs of engaging portions are provided, but the present invention is not limited to this case, and a single pair of engaging portions may be provided, or three or more pairs of engaging portions may be provided.
Further, in the above-described embodiment, plate-shaped members 631 and oscillators 641B are in contacted with each other, but from the viewpoint of abrasion resistance of a plate-shaped member (passive element), a coating layer such as diamond-like carbon or ceramic may be formed on a surface of the plate-shaped member. In a case where the ceramic is coated on plate-shaped members 631, the hardness of plate-shaped members 631 becomes, for example, equal to or more of the hardness of resonant portion 641, that is, becomes higher than the hardness of resonant portion 641.
Further, in the above-described embodiment, a configuration including two guide shafts is employed, but the present invention is not limited to this case. The present invention may have a configuration having, for example, three or more guide shafts. The present invention may also have a configuration including a single guide shaft.
In the above-described embodiment, support shafts 50 are provided on both sides in the X-direction, but the present invention is not limited to this, and support shaft 50 may be provided on only one side in the X-direction.
In the above-described embodiment, side wall portion 11 and bottom wall portion 12 of housing 10 are formed by insert molding. However, the present invention is not limited to this, and the bottom wall portion may be adhesively fixed to side wall portion 11.
Further, the above-described embodiment employs the configuration having two movable lenses composed of second lens unit 32 and third lens unit 33, but the present invention is not limited to this, and the configuration may have a single movable lens, or three or more movable lenses.
Further, the above-described embodiment employs the configuration having four lens units, but the present invention is not limited to this, and any number of lens units may be provided as long as the configuration has at least one movable lens. In addition, in the case of a configuration including one movable lens, the number of lens driving parts is also one.
In the above-described embodiment, interposition part 63 is formed by bending a plate-like metal member, but the present invention is not limited to this case, and the main body portion and the engaging portion that compose the interposition part may be formed by separate members.
In the above-described embodiment, frame 61 and supporting member 632 of interposition part 63 are formed by separate members, but the present invention is not limited to this. For example, frame 61 and supporting member 632 may be integrally formed.
In the above-described embodiment, each of connecting parts 62 connecting together frame 61 and the lens unit is configured with the spring member, but the present invention is not limited to this, and the connecting part may be configured with any member as long as it is a member having elasticity.
Further, in the above-described embodiment, third portion 611C of frame 61 is disposed to be spaced apart from second guide shaft 82, but the present invention is not limited to this, and a configuration may also be used in which the third portion may also support the second guide shaft.
The above-described embodiment has the configuration in which the bottom wall portion includes the bent portions or half punches, but the present invention is not limited to this, and a configuration may also be used in which the bottom wall portion does not include any bent portion or half punch.
In the above-described embodiment, resonant portion 641 includes two oscillators 641B, but the present invention is not limited to this, and the present invention may have a configuration in which the resonant portion includes one oscillator, for example. In this case, however, one plate-shaped member is provided.
In the above-described embodiment, the drive control part, the reflection drive control part, and the image capturing control part are provided separately, but the present invention is not limited to this, and at least two of the drive control part, the reflection drive control part, and the image capturing control part may be composed of one control part.
Further, although bearing portion 114A is provided in the above embodiment, the present invention is not limited to this, and the present invention does not have to be provided with any bearing portion.
For example, while a smartphone serving as a camera-equipped mobile terminal has been described in the above embodiment as an example of the camera-mounted device including camera module 1, the present invention is applicable to a camera-mounted device including a camera module and an image processing part that processes image information obtained by the camera module. The camera-mounted device encompasses an information apparatus and a transporting apparatus. Examples of the information apparatuses include a camera-equipped mobile phone, a note-type personal computer, a tablet terminal, a mobile game machine, a web camera, a drone, and a camera-equipped in-vehicle device (e.g., a rear-view monitor device or a drive recorder device). In addition, examples of the transporting apparatuses include an automobile, a drone.
In addition, the above-described embodiments merely describe examples of implementations for practicing the present invention, and should not be construed as limiting the technical scope of the present invention. That is, the present invention can be embodied in various forms without departing from the spirit, scope, or principal features of the present invention. For example, the shape, size, number, and material of each part described in the above embodiment are merely examples, and can be changed as appropriate.
The disclosure of U.S. provisional Patent Application No. 63/113,224, filed on Nov. 13, 2020, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
The driving unit according to the present invention is useful as a driving unit, a lens driving device, a camera module, and a camera-mounted device each capable of improving the stability of driving performance of an ultrasonic motor.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/037359 | 10/8/2021 | WO |
Number | Date | Country | |
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63113224 | Nov 2020 | US |