actuator

Abstract

An actuator for vibrating an optical element, which is capable of improving durability of a fulcrum portion that is a rotation fulcrum of a movable body holding the optical element, even if the optical element is continuously vibrated at a relatively high frequency. In the actuator (1), a fulcrum portion (6) that is a fulcrum of rotation of a movable body (3) with respect to a fixed body (4) is provided with a ball (11) made of ceramic, a ball holding member (12) mounted on the movable body and used for holding the ball, and a ball support member (13) mounted on the fixed body. The ball is arranged on an inner peripheral side of a cylindrical portion of the ball holding member formed in a bottomed cylindrical shape, and a through hole is formed in a bottom portion of the ball holding member for arranging a part of the ball arranged on the inner peripheral side of the cylindrical portion outside the ball holding member. A concave curved surface-shaped contact surface formed on the ball support member is in contact with a part of the ball arranged outside the ball holding member at a prescribed contact pressure.

Description

Technical Field

[0001] The present invention relates to an actuator for vibrating optical elements. Background Technology

[0002] Previously, pixel shifting devices for vibrating a glass plate (optical glass) that transmits projected light were known (for example, see Patent Document 1). The pixel shifting device described in Patent Document 1 is installed in a projector. This pixel shifting device includes a glass frame for fixing the glass plate and a base for rotatably holding the glass frame. The glass frame and the base are formed in a quadrilateral frame shape. The glass plate is disposed on the inner periphery of the glass frame. The glass frame is disposed on the inner periphery of the base.

[0003] In the pixel shifting device described in Patent Document 1, a bearing and a spindle are arranged between the glass frame and the base, serving as a fulcrum for the rotation of the glass frame relative to the base. The spindle is fixed to the glass frame in such a way that it protrudes towards the outer periphery of the glass frame along one diagonal. The bearing is fixed to the base at a corner along one diagonal of the quadrilateral frame. The bearing is a cylindrical sliding bearing. The spindle is inserted into the inner periphery of the bearing.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-215466 Summary of the Invention

[0007] In the pixel shifting device described in Patent Document 1, the glass frame and the glass plate vibrate continuously at a relatively high frequency. For example, in this pixel shifting device, the glass frame vibrates continuously at 60 Hz. Therefore, in this pixel shifting device, it is preferable to improve the durability of the fulcrum portion that serves as the pivot point for the rotation of the glass frame relative to the base.

[0008] Therefore, the objective of this invention is to provide an actuator for vibrating an optical element, which can improve the durability of the fulcrum portion, which serves as the rotation fulcrum for holding the optical element, even when the optical element vibrates continuously at a relatively high frequency.

[0009] To address the aforementioned issues, the actuator of the present invention is characterized by comprising: a movable body that holds optical elements; a fixed body formed as a frame with the movable body disposed on its inner periphery and holding the movable body so as to be rotatable; a magnetic drive mechanism that rotates the movable body in a direction in which the movable body is inclined relative to the fixed body; and a fulcrum portion that serves as a fulcrum for the rotation of the movable body relative to the fixed body, the fulcrum portion comprising: a ceramic sphere; a sphere holding member that is mounted on either the movable body or the fixed body and is used to hold the sphere; and a sphere support portion. The ball retainer is formed with a concave curved contact surface that contacts a portion of a ball with a specified contact pressure, and is mounted on either a movable body or a fixed body. The ball retainer is formed as a bottomed cylindrical part with a cylindrical portion and a bottom connected to one end of the cylindrical portion. The ball is disposed on the inner circumferential side of the cylindrical portion, and a through hole is formed at the bottom. The through hole is used to allow a portion of the ball disposed on the inner circumferential side of the cylindrical portion to be disposed on the outside of the ball retainer, and the contact surface contacts the portion of the ball disposed on the outside of the ball retainer.

[0010] In the actuator of the present invention, the fulcrum portion includes a ceramic sphere. Therefore, in the present invention, even when the optical element vibrates continuously at a relatively high frequency, the durability of the fulcrum portion can be improved. Furthermore, in the present invention, the sphere holding member for holding the sphere is formed as a bottomed cylindrical shape, having a cylindrical portion on the inner circumference of the sphere and a bottom connected to one end of the cylindrical portion. A through hole is formed in the bottom for disposing a portion of the sphere disposed on the inner circumference of the cylindrical portion outside the sphere holding member. Therefore, in the present invention, even if the sphere is made of ceramic, and even if the outer diameter of the sphere is small, the sphere, with a portion in contact with the contact surface of the sphere support member on the outside of the sphere holding member, can be easily mounted on a movable or fixed body using the sphere holding member.

[0011] In this invention, for example, the optical element is formed in the shape of a flat plate, and the fulcrum is disposed at both ends of a movable body in a first orthogonal direction orthogonal to the thickness direction of the optical element.

[0012] In this invention, for example, a ball holding member is mounted on a movable body, and a ball supporting member is mounted on a fixed body. The movable body has protrusions extending to both sides in a first orthogonal direction and inserted into the cylindrical portion. A recess for arranging a portion of the ball is formed on the front end face of the protrusion, and a contact surface contacts a portion of the ball from the outside in the first orthogonal direction. In this case, because the recess for arranging a portion of the ball is formed on the front end face of the protrusion, the state of the ball mounted on the movable body can be stabilized.

[0013] In this invention, the preferred spherical support member is a leaf spring formed in a U-shape, meaning the leaf spring's shape is U-shaped when viewed from the thickness direction of the optical element. With this configuration, compared to the case where the leaf spring's shape is U-shaped when viewed from a direction orthogonal to both the thickness direction of the optical element and the first orthogonal direction, the leaf spring can be miniaturized in the thickness direction of the optical element. Therefore, the actuator can be miniaturized in the thickness direction of the optical element.

[0014] In this invention, the actuator may also include a leaf spring having spherical support members disposed at both ends of the movable body in the first orthogonal direction and a flat plate-shaped connecting portion connecting the two spherical support members. The connecting portion is frame-shaped and fixed to one side of the optical element of the movable body or the fixed body in the thickness direction.

[0015] In this configuration, since the two ball support components are integrated via a connecting portion, the number of actuator components can be reduced compared to the case where two separate ball support components are provided. Furthermore, since the two ball support components are mounted on the movable or fixed body by fixing the connecting portion to the movable or fixed body, the assembly time of the actuator can be reduced compared to the case where two separate ball support components are each fixed to a movable or fixed body.

[0016] Furthermore, in this configuration, by fixing the frame-shaped connecting portion to the movable or fixed body and mounting the two spherical support members to the movable or fixed body, the fixed area of ​​the connecting portion relative to the movable or fixed body can be ensured, thereby improving the mounting strength of the spherical support members relative to the movable or fixed body. Additionally, in this configuration, the two spherical support members are integrated via the connecting portion, and the deviation in their relative positions is determined by the component precision of the leaf spring. Therefore, compared to the case where the two spherical support members are separately fixed to the movable or fixed body, the deviation in their relative positions can be suppressed.

[0017] In this invention, it is preferable to form reinforcing ribs on the sphere support member. With this configuration, the strength of the sphere support member can be ensured even if the thickness of the sphere support member becomes thinner.

[0018] As described above, in the present invention, in the actuator used to vibrate the optical element, even when the optical element vibrates continuously at a relatively high frequency, the durability of the fulcrum portion, which serves as the rotation fulcrum of the movable body holding the optical element, can be improved. Attached Figure Description

[0019] Figure 1 This is a perspective view of the actuator according to an embodiment of the present invention.

[0020] Figure 2 yes Figure 1 The top view of the actuator shown.

[0021] Figure 3 yes Figure 1 An exploded perspective view of the actuator shown.

[0022] Figure 4 (A) is Figure 2 A sectional view of the EE section. Figure 4 (B) is Figure 2 A sectional view of the FF section.

[0023] Figure 5 yes Figure 3 Enlarged view of the sphere, sphere holding component, and sphere supporting component shown.

[0024] Figure 6 It is used for explanation Figure 2 An enlarged view of the structure of part G.

[0025] Figure 7 These are diagrams of leaf springs according to other embodiments of the present invention, (A) being a top view and (B) being a perspective view.

[0026] Figure 8 This is a top view used to illustrate the structure of the fulcrum portion in other embodiments of the present invention.

[0027] Figure 9 yes Figure 7 Enlarged view of part J of (B). Detailed Implementation

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0029] (Overall structure of the actuator)

[0030] Figure 1 This is a perspective view of the actuator 1 according to an embodiment of the present invention. Figure 2 yes Figure 1 The top view of actuator 1 shown. Figure 3 yes Figure 1 An exploded perspective view of actuator 1 is shown.

[0031] In the following explanation, such as Figure 1 As shown, the three mutually orthogonal directions are designated as the X, Y, and Z directions, respectively. The X direction is designated as the left-right direction, the Y direction as the front-back direction, and the Z direction as the up-down direction. Additionally, one side, which is designated as the left-right direction... Figure 1 The X1 direction side is set as the "right" side, and will be the opposite side. Figure 1 The X2 direction side is set as the "left" side, which will be the side used for the front-back direction. Figure 1 The Y1 direction side is designated as the "front" side, and the opposite side is designated as the "back" side. Figure 1 The Y2 direction side is designated as the "rear" side, which will be the side that acts as the vertical direction. Figure 1 The Z1 direction side is designated as the "up" side, and the opposite side will be... Figure 1 The Z2 direction side is set as the "down" side.

[0032] The actuator 1 in this embodiment is a device for vibrating the optical glass 2, which is an optical element, and is used in a projector. The optical glass 2 is a light-transmitting glass plate formed into a square flat plate. The optical glass 2 constitutes part of the projection optical system of the projector. In order to improve the image quality of the image projected by the projector, the actuator 1 causes the optical glass 2 to vibrate at a predetermined frequency and angle, periodically changing the orientation of the optical glass 2. For example, the actuator 1 causes the optical glass 2 to vibrate at 60Hz.

[0033] The actuator 1 is integrally formed as a thin, flat cuboid in the vertical direction. The actuator 1 includes a movable body 3 that holds the optical glass 2 and a fixed body 4 that rotatably holds the movable body 3. The movable body 3 and the fixed body 4 are frame-shaped. The optical glass 2 is disposed on the inner periphery of the movable body 3. The movable body 3 is disposed on the inner periphery of the fixed body 4. Furthermore, the actuator 1 includes: a magnetic drive mechanism 5 that causes the movable body 3 to rotate in a direction inclined relative to the fixed body 4, thereby causing the optical glass 2 to vibrate; a fulcrum 6 that serves as a fulcrum for the rotation of the movable body 3 relative to the fixed body 4; and a holding magnet 7 and magnetic plates 8 and 9 for holding the movable body 3 in a fixed position relative to the fixed body 4 in the direction of rotation of the movable body 3 relative to the fixed body 4.

[0034] In this embodiment, when no current is supplied to the drive coil 16 (described later) which constitutes part of the magnetic drive mechanism 5 (i.e., when the drive coil 16 is not energized), the movable body 3 is positioned at a predetermined reference position relative to the fixed body 4 in the direction of rotation of the movable body. In the direction of rotation of the movable body, when the movable body 3 is positioned at the reference position relative to the fixed body 4, the thickness direction of the optical glass 2 is aligned with the vertical direction.

[0035] Furthermore, in the direction of rotation of the movable body, when the movable body 3 is positioned at a reference position relative to the fixed body 4, in the actuator 1 of the projector, the thickness direction of the optical glass 2 is aligned with the optical axis direction of the projector's projection optical system, and the optical axis of the projector's projection optical system passes through the center of the optical glass 2. Additionally, the rotation angle of the movable body 3 relative to the fixed body 4 when the optical glass 2 vibrates is, for example, less than 0.5°, which is very small. Therefore, regardless of whether the optical glass 2 vibrates, the thickness direction of the optical glass 2 is approximately aligned with the vertical direction.

[0036] When viewed from the outer periphery of the fixed body 4, the movable body 3 is capable of rotating in a direction inclined relative to the fixed body 4. Furthermore, the movable body 3 is capable of rotating in a first orthogonal direction orthogonal to the thickness direction of the optical glass 2. Figure 2 The movable body 3 can rotate relative to the fixed body 4 with the V direction as the axis of rotation. That is, the movable body 3 can rotate with respect to the axis L1 (refer to the first orthogonal direction) as the axis of rotation. Figure 2 The rotation center is relative to the fixed body 4. The first orthogonal direction is orthogonal to the vertical direction. Furthermore, when viewed from above, the first orthogonal direction is relative to the front-back direction. Figure 2 The axis L1 is offset by 45° clockwise. When viewed from the thickness direction of the optical glass 2, the axis L1 passes through the center of the optical glass 2. The fulcrum 6 is disposed on both ends of the movable body 3 in the first orthogonal direction.

[0037] The movable body 3 is a glass holder that holds the optical glass 2. The movable body 3 is formed of a non-magnetic material. Alternatively, the movable body 3 is formed of a resin material. As described above, the movable body 3 is formed in a frame shape. Specifically, the movable body 3 is formed in a square or rectangular frame shape. In the direction of rotation of the movable body, when the movable body 3 is positioned at a reference position relative to the fixed body 4, two of the four sides of the outer peripheral surface of the movable body 3, which has a square or rectangular shape, are parallel to the left-right direction, and the remaining two sides are parallel to the front-back direction.

[0038] The movable body 3 has a magnet placement recess 3a for arranging the driving magnet 15 (described later) which forms part of the magnetic drive mechanism 5, and a magnet placement recess 3b for arranging the holding magnet 7. The magnet placement recess 3a is recessed from the right end of the movable body 3 to the left. The magnet placement recess 3b is recessed from the left end of the movable body 3 to the right. The magnet placement recesses 3a and 3b are formed over the entire area of ​​the movable body 3 in the thickness direction of the optical glass 2.

[0039] Furthermore, protrusions 3c protruding to both sides in the first orthogonal direction are formed on the movable body 3. That is, a protrusion 3c protruding to the right rear side and a protrusion 3c protruding to the left front side are formed on the movable body 3. The protrusions 3c are formed in a cylindrical shape. The axial direction of the cylindrical protrusions 3c is aligned with the first orthogonal direction. A recess 3d is formed on the front end face of the protrusions 3c (see reference). Figure 4 The recess 3d has a portion of the sphere 11 (described later) that forms part of the fulcrum portion 6. The recess 3d is recessed inward from the front end of the protrusion 3c toward the first orthogonal direction. Furthermore, the recess 3d is formed in a circular shape. The center of the circular recess 3d is positioned on the axis of the cylindrical protrusion 3c.

[0040] As described above, the optical glass 2 is disposed on the inner circumference of the movable body 3. The optical glass 2 is fixed to the movable body 3. In the rotation direction of the movable body, when the movable body 3 is disposed at a reference position relative to the fixed body 4, two of the four sides of the outer circumferential surface of the optical glass 2, which has a square shape, are parallel to the left-right direction, and the remaining two sides are parallel to the front-back direction.

[0041] The fixing body 4 is formed of a non-magnetic material. Alternatively, the fixing body 4 may be formed of a resin material. As described above, the fixing body 4 is frame-shaped. Specifically, the fixing body 4 is formed as a square or rectangular frame. Two of the four sides of the outer periphery of the fixing body 4, which has a square or rectangular shape, are parallel to the left-right direction, and the remaining two sides are parallel to the front-back direction. A coil arrangement recess 4a for arranging the drive coil 16 (described later) which constitutes part of the magnetic drive mechanism 5, and a magnetic plate arrangement recess 4b for arranging the magnetic plate 9 are formed on the fixing body 4.

[0042] A coil mounting recess 4a and a magnetic plate mounting recess 4b are formed on the right side of the fixture 4. The coil mounting recess 4a is recessed from the left end of the right side of the fixture 4 towards the right. The coil mounting recess 4a is formed over the entire vertical area of ​​the fixture 4. The magnetic plate mounting recess 4b is formed to the right of the coil mounting recess 4a. The magnetic plate mounting recess 4b is recessed further to the right than the coil mounting recess 4a. The magnetic plate mounting recess 4b is not formed over the entire vertical area of ​​the fixture 4; a magnetic plate mounting portion 4c for mounting the magnetic plate 9 is formed at the lower end of the right side of the fixture 4 (see reference). Figure 2 The upper surface of the magnetic plate mounting part 4c becomes a plane orthogonal to the vertical direction.

[0043] Additionally, the fixing body 4 includes: a spring mounting portion 4d, which houses the leaf spring 13 (described later) that forms part of the fulcrum portion 6; and a magnetic plate mounting hole 4e, which mounts and fixes the magnetic plate 8. The spring mounting portion 4d is formed at two corners along a diagonal of the fixing body 4, which is a square or rectangular frame. Specifically, the spring mounting portion 4d is formed at the right rear corner and the left front corner of the fixing body 4. The magnetic plate mounting hole 4e is formed on the left side of the fixing body 4. The magnetic plate mounting hole 4e is a through hole that penetrates the fixing body 4 in the vertical direction. Furthermore, the magnetic plate mounting hole 4e is a rectangular square hole that is elongated in the front-back direction.

[0044] As described above, the fulcrum portion 6 is disposed on both ends of the movable body 3 in the first orthogonal direction. That is, the fulcrum portion 6 is disposed at the corner of the right rear end and the corner of the left front end of the actuator 1. The fulcrum portion 6 includes: a sphere 11 formed in a spherical shape; a ball holding member 12 for holding the ball 11; and a leaf spring 13 as a ball support member, the leaf spring 13 having a concave curved contact surface 13a that contacts a portion of the ball 11 with a predetermined contact pressure (see reference). Figure 4 (etc.). The specific structure of the fulcrum 6 will be described later.

[0045] The magnetic drive mechanism 5 includes a drive magnet 15 and a drive coil 16 disposed opposite to the drive magnet 15. The drive magnet 15 is fixed to the movable body 3. Specifically, the drive magnet 15 is disposed in the magnet placement recess 3a and fixed to the right side of the movable body 3. The drive magnet 15 is formed into a long rectangular parallelepiped shape that is slender in the front-rear direction. The drive magnet 15 is composed of two magnetized portions 15a that are polarized in the thickness direction of the optical glass 2.

[0046] The driving coil 16 is, for example, a hollow coil formed by winding a wire into a hollow shape. The driving coil 16 is mounted on a flexible printed circuit board 17. Furthermore, the driving coil 16 is disposed in a coil placement recess 4a. The flexible printed circuit board 17 is fixed to a mounting body 4. The driving coil 16 is fixed to the mounting body 4 via the flexible printed circuit board 17. The driving magnet 15 and the driving coil 16 are opposite each other in the left-right direction.

[0047] The magnetic drive mechanism 5 rotates the movable body 3 relative to the fixed body 4 with the first orthogonal direction as the axis of rotation. Additionally, a Hall sensor (not shown) is mounted on the flexible printed circuit board 17 to detect the rotational position of the movable body 3 relative to the fixed body 4. The Hall sensor is positioned opposite the drive magnet 15. Current is supplied to the drive coil 16 based on the detection result of the Hall sensor.

[0048] The retaining magnet 7 is fixed to the movable body 3. Specifically, the retaining magnet 7 is disposed in the magnet placement recess 3b and fixed to the left side of the movable body 3. The retaining magnet 7 is formed into a long and narrow cuboid shape in the front-back direction. In addition, the retaining magnet 7 is constructed in the same way as the driving magnet 15, consisting of two magnetized parts 7a that are polarized in the thickness direction of the optical glass 2.

[0049] like Figure 2 As shown, the center of the retaining magnet 7 in the front-rear direction is offset from the center of the driving magnet 15 in the front-rear direction. Specifically, the center of the retaining magnet 7 in the front-rear direction is located behind the center of the driving magnet 15 in the front-rear direction. In this embodiment, when viewed from the thickness direction of the optical glass 2, the retaining magnet 7 and the driving magnet 15 are arranged in a point-symmetric manner with respect to the center of the movable body 3. Furthermore, when viewed from the thickness direction of the optical glass 2, the retaining magnet 7 and the driving magnet 15 are arranged in a point-symmetric manner with respect to the center of the optical glass 2.

[0050] The magnetic plate 8 is formed of a magnetic metal material. The magnetic plate 8 is formed in a flat plate shape. Specifically, the magnetic plate 8 is formed in a long, narrow rectangular flat plate shape. The magnetic plate 8 is thin. For example, the thickness of the magnetic plate 8 is approximately 0.1 to 0.2 mm. The magnetic plate 8 is arranged such that its thickness direction is aligned with its left-right direction. Furthermore, the magnetic plate 8, being a rectangular flat plate, is arranged such that its long side direction is aligned with its front-back direction. The magnetic plate 8 is disposed in and fixed within the magnetic plate placement hole 4e. That is, the magnetic plate 8 is fixed to the fixing body 4. The magnetic plate 8 is fixed to the fixing body 4 using an adhesive. In this embodiment, the position of the magnetic plate 8 in the vertical direction is adjusted before fixing it to the fixing body 4.

[0051] Magnetic plate 9 is constructed in the same manner as magnetic plate 8. Magnetic plate 9 is arranged such that its thickness direction aligns with its left-right direction. Furthermore, magnetic plate 9 is arranged such that its long side, formed as a rectangular flat plate, aligns with its front-back direction. Magnetic plate 9 is disposed within magnetic plate placement recess 4b. Magnetic plate 9 is mounted on magnetic plate mounting portion 4c, with its lower end face contacting the upper surface of the magnetic plate mounting portion 4c. That is, magnetic plate 9 is positioned in the vertical direction. Additionally, magnetic plate 9 is fixed to flexible printed circuit board 17 and thus fixed to the fixing body 4 via flexible printed circuit board 17.

[0052] Magnetic plate 8 is disposed to the left of holding magnet 7, and magnetic plate 9 is disposed to the right of driving magnet 15. In this embodiment, magnetic attraction forces are generated between magnetic plate 8 and holding magnet 7, and between magnetic plate 9 and driving magnet 15, for holding movable body 3 in a fixed position in the direction of movable body rotation when driving coil 16 is not energized. Specifically, magnetic attraction forces are generated between magnetic plate 8 and holding magnet 7, and between magnetic plate 9 and driving magnet 15, for holding movable body 3 in a reference position in the direction of movable body rotation when driving coil 16 is not energized.

[0053] Furthermore, in this embodiment, by adjusting the position of the magnetic plate 8 in the vertical direction, the position of the movable body 3 in the rotation direction of the movable body when the drive coil 16 is not energized can be adjusted. That is, in this embodiment, the position of the movable body 3 in the rotation direction of the movable body when the drive coil 16 is not energized is determined by the vertical position of the magnetic plate 8.

[0054] (The composition of the fulcrum and its surrounding parts)

[0055] Figure 4 (A) is Figure 2 A sectional view of the EE section. Figure 4 (B) is Figure 2 A sectional view of the FF section. Figure 5 yes Figure 3 Enlarged view of the sphere 11, the sphere retaining component 12, and the leaf spring 13 shown. Figure 6 It is used for explanation Figure 2 An enlarged view of the structure of part G.

[0056] As described above, the fulcrum portion 6 includes a sphere 11, a sphere retaining member 12, and a leaf spring 13. The sphere 11 is formed of ceramic. For example, the sphere 11 is formed of zirconium oxide. The sphere retaining member 12 is formed of a metallic material. The sphere retaining member 12 is formed into a bottomed cylindrical shape, having a cylindrical portion 12a and a bottom 12b connected to one end of the cylindrical portion 12a. Specifically, the cylindrical portion 12a is formed into a cylindrical shape, and the sphere retaining member 12 is formed into a bottomed cylindrical shape. The inner diameter of the cylindrical portion 12a is larger than the outer diameter of the sphere 11.

[0057] A ball retaining member 12 is mounted on the movable body 3. Specifically, the ball retaining member 12 is fixed to the protrusion 3c of the movable body 3. The protrusion 3c is inserted into the cylindrical portion 12a. Furthermore, the protrusion 3c is gently pressed into the inner circumference of the cylindrical portion 12a from the inside in the first orthogonal direction. The ball retaining member 12 is fixed to the protrusion 3c with adhesive. The ball 11 is disposed on the inner circumference of the cylindrical portion 12a. The bottom 12b is disposed at a position further outward in the first orthogonal direction than the front end face of the protrusion 3c. A gap for disposing of the ball 11 is formed between the front end face of the protrusion 3c and the bottom 12b.

[0058] A through hole 12c is formed on the bottom 12b, which is used to allow a portion of the sphere 11 disposed on the inner circumferential side of the cylindrical portion 12a to be disposed on the outside of the sphere holding member 12. The through hole 12c is formed at the center of the bottom 12b. In addition, the through hole 12c is formed in a circular shape. Therefore, the bottom 12b is formed in an annular shape. The inner diameter of the through hole 12c is smaller than the outer diameter of the sphere 11. As described above, the sphere 11 is disposed on the inner circumferential side of the cylindrical portion 12a. The sphere 11 contacts the bottom surface of the recess 3d and contacts the edge of the through hole 12c. A portion of the sphere 11 is disposed at a position further outward in the first orthogonal direction than the bottom 12b. That is, a portion of the sphere 11 is disposed on the outside of the sphere holding member 12. The sphere 11 is held on the movable body 3 by the protrusion 3c and the sphere holding member 12.

[0059] The leaf spring 13 is formed by bending a metal plate, such as a flexible stainless steel plate, into a predetermined shape. In this embodiment, the leaf spring 13 is U-shaped and consists of a first flat plate portion 13b and a second flat plate portion 13c, both formed as flat plates, and a curved plate portion 13d connecting one end of the first flat plate portion 13b and one end of the second flat plate portion 13c. The leaf spring 13 is arranged in the spring arrangement portion 4d such that its shape is U-shaped when viewed from above. That is, the shape of the leaf spring 13 when viewed from above is U-shaped. Furthermore, as described above, since the thickness direction of the optical glass 2 is approximately the same as the vertical direction, the shape of the leaf spring 13 when viewed from the thickness direction of the optical glass 2 is also U-shaped.

[0060] The first flat plate portion 13b is arranged such that its thickness direction aligns with the first orthogonal direction, and the second flat plate portion 13c is arranged such that its thickness direction aligns with the first orthogonal direction. The first flat plate portion 13b is positioned further outward than the second flat plate portion 13c in the first orthogonal direction. In the leaf spring 13 located at the right rear corner of the fixing body 4, the right front end of the first flat plate portion 13b and the right front end of the second flat plate portion 13c are connected by a curved plate portion 13d. In the leaf spring 13 located at the left front corner of the fixing body 4, the left rear end of the first flat plate portion 13b and the left rear end of the second flat plate portion 13c are connected by a curved plate portion 13d.

[0061] When viewed from the thickness direction of the optical glass 2, the leaf spring 13 located at the right rear end and the leaf spring 13 located at the left front end are arranged in a point-symmetrical manner with respect to the center of the optical glass 2. The leaf spring 13 is fixed to the spring mounting portion 4d in a positioned state. That is, the leaf spring 13 is mounted on the fixing body 4. In addition, the leaf spring 13 is fixed to the spring mounting portion 4d by adhesive.

[0062] The aforementioned contact surface 13a is formed at the front end of the first plate portion 13b. The contact surface 13a is a concave curved surface recessed outward toward the first orthogonal direction. A through hole 13e for inserting the ball retaining member 12 is formed on the second plate portion 13c. The inner diameter of the through hole 13e is larger than the outer diameter of the ball retaining member 12. At both ends of the portion of the second plate portion 13c where the through hole 13e is formed in the vertical direction, reinforcing portions 13f are formed to ensure the strength of this portion. The reinforcing portions 13f extend slightly outward toward the first orthogonal direction from both ends of the second plate portion 13c in the vertical direction.

[0063] The contact surface 13a contacts a portion of the ball 11 disposed outside the ball retaining member 12 from the outside in the first orthogonal direction with a predetermined contact pressure. The leaf spring 13 applies force to the ball 11 towards the inside in the first orthogonal direction. In addition, when the leaf spring 13 is disposed on the spring mounting portion 4d, the ball retaining member 12, which is fixed to the movable body 3, is inserted into the through hole 13e.

[0064] (Main effects of this implementation method)

[0065] As described above, in this embodiment, the fulcrum 6 includes a ceramic sphere 11. Therefore, in this embodiment, even when the optical glass 2 vibrates continuously at a relatively high frequency, the durability of the fulcrum 6 can be improved. Furthermore, in this embodiment, the sphere holding member 12 is formed as a bottomed cylindrical shape, having a cylindrical portion 12a on its inner circumference where the sphere 11 is disposed, and a bottom portion 12b connected to one end of the cylindrical portion 12a. A through hole 12c is formed on the bottom portion 12b for disposing a portion of the sphere 11 on the outside of the sphere holding member 12. Therefore, in this embodiment, even if the sphere 11 is made of ceramic, and even if the outer diameter of the sphere 11 is small, the sphere 11, with a portion contacting the contact surface 13a of the leaf spring 13 on the outside of the sphere holding member 12, can be easily mounted on the movable body 3 using the sphere holding member 12.

[0066] In this embodiment, a recess 3d is formed on the front end face of the protrusion 3c of the movable body 3, in which a portion of the ball 11 is disposed. Therefore, in this embodiment, the ball 11 held on the movable body 3 can be stabilized by the protrusion 3c and the ball holding member 12. In addition, in this embodiment, since the ball holding member 12 fixed to the movable body 3 passes through the through hole 13e of the leaf spring 13 fixed to the fixed body 4, it is possible to prevent the movable body 3 from falling off the fixed body 4 to the upper or lower side.

[0067] (Example of a variation of a leaf spring)

[0068] Figure 7 These are diagrams of the leaf spring 23 according to other embodiments of the present invention, (A) is a top view and (B) is a perspective view. Figure 8 This is a top view used to illustrate the structure of the fulcrum portion 6 in other embodiments of the present invention. Figure 9 yes Figure 7 Enlarged view of part J of (B).

[0069] In the above embodiment, two separate leaf springs 13 are disposed at both ends of the movable body 3 in the first orthogonal direction. However, the actuator 1 may also have one leaf spring 23 instead of two leaf springs 13. The leaf spring 23 is formed by bending a metal plate such as a flexible stainless steel plate into a predetermined shape. The thickness of the leaf spring 23 is, for example, 0.2 mm. The leaf spring 23 includes: spring portions 23b, which are disposed at both ends of the movable body 3 in the first orthogonal direction and serve as ball support members; and a flat plate-shaped connecting portion 23c connecting the two spring portions 23b. In this modified example, the leaf spring 23 is composed of two spring portions 23b and a connecting portion 23c.

[0070] The connecting portion 23c is formed in a frame shape. Specifically, the connecting portion 23c is formed in a generally square or generally rectangular frame shape. The connecting portion 23c is fixed to the upper end surface of the frame-shaped fixing body 4. That is, the connecting portion 23c is fixed to one side of the optical glass 2 of the fixing body 4 in the thickness direction. Figure 3 As shown, the upper surface of the fixing body 4 is a plane orthogonal to the vertical direction. The connecting part 23c is fixed to the upper surface of the fixing body 4 in such a way that the thickness direction of the connecting part 23c, which is formed as a flat plate, is aligned with the vertical direction. In addition, the connecting part 23c is fixed to the upper surface of the fixing body 4 by an adhesive.

[0071] Two of the four sides of the outer periphery of the connecting portion 23c, which is roughly square or roughly rectangular in shape, are parallel to the left-right direction, and the remaining two sides are parallel to the front-back direction. A portion of the inner periphery of the frame-shaped connecting portion 23c overlaps with a portion of the outer periphery of the frame-shaped movable body 3 in the vertical direction. The connecting portion 23c also functions to limit the upward movement range of the movable body 3 relative to the fixed body 4. In addition, a limiting portion is formed on the fixed body 4 to limit the downward movement range of the movable body 3 relative to the fixed body 4.

[0072] The spring portion 23b is connected to both ends of the connecting portion 23c in the first orthogonal direction. The spring portion 23b is formed as a flat plate. The spring portion 23b is configured such that the thickness direction of the spring portion 23b is consistent with the first orthogonal direction. The spring portion 23b is disposed on the lower side of the connecting portion 23c. That is, both ends of the leaf spring 23 in the first orthogonal direction are bent downward at right angles. At the right rear corner of the connecting portion 23c, the right front end of a spring portion 23b that becomes the base end of another spring portion 23b is connected to the connecting portion 23c. At the left front corner of the connecting portion 23c, the left rear end of another spring portion 23b that becomes the base end of another spring portion 23b is connected to the connecting portion 23c.

[0073] When viewed from the thickness direction of the optical glass 2, the two spring portions 23b are arranged symmetrically with respect to the center of the optical glass 2. As described above, the connecting portion 23c is fixed to the upper end surface of the fixing body 4. That is, the two spring portions 23b, which are integrally formed with the connecting portion 23c, are mounted on the fixing body 4 via the connecting portion 23c.

[0074] A contact surface 23a, corresponding to the contact surface 13a of the leaf spring 13, is formed at the front end of the spring portion 23b (see reference). Figure 7 (B) That is, a concave contact surface 23a is formed on the spring portion 23b, which contacts a portion of the ball 11 with a predetermined contact pressure. The contact surface 23a is a concave surface recessed towards the outer side of the first orthogonal direction. The contact surface 23a contacts a portion of the ball 11 disposed outside the ball holding member 12 from the outer side of the first orthogonal direction with a predetermined contact pressure. The spring portion 23b applies force to the ball 11 towards the inner side of the first orthogonal direction. In this modified example, the fulcrum portion 6 is constituted by the ball 11, the ball holding member 12, and the spring portion 23b.

[0075] A reinforcing rib 23d is formed on the spring portion 23b. The rib 23d is formed by deep drawing a portion of the spring portion 23b. The rib 23d protrudes outward in the first orthogonal direction. The rib 23d has an L-shape when viewed from the first orthogonal direction.

[0076] In this modified example, the two spring portions 23b are integrated via the connecting portion 23c. Therefore, compared to the case where two separate leaf springs 13 are provided as in the above embodiment, the number of components in the actuator 1 can be reduced. Furthermore, in this modified example, the two spring portions 23b are mounted to the fixed body 4 by fixing the connecting portion 23c to the fixed body 4. Therefore, compared to the case where the two separate leaf springs 13 are each fixed to the fixed body 4 as in the above embodiment, the assembly time of the actuator 1 can be reduced.

[0077] Furthermore, in this modified example, by bonding and fixing the frame-shaped connecting portion 23c to the frame-shaped fixing body 4 and thus mounting the two spring portions 23b to the fixing body 4, the bonding area of ​​the connecting portion 23c relative to the fixing body 4 can be ensured, thereby improving the mounting strength of the spring portions 23b relative to the fixing body 4. Additionally, in this modified example, the two spring portions 23b are integrated via the connecting portion 23c, and the deviation in the relative position of the two spring portions 23b is determined by the component precision of the leaf spring 23. Therefore, compared to the case where the two separately formed leaf springs 13 are each fixed to the fixing body 4 as in the above embodiment, the deviation in the relative position of the two contact surfaces 23a can be suppressed.

[0078] Furthermore, in this modified example, since a reinforcing rib 23d is formed on the spring portion 23b, the strength of the spring portion 23b can be ensured even if the thickness of the leaf spring 23 becomes thinner. Alternatively, as long as the strength of the spring portion 23b can be ensured, the rib 23d may not need to be formed on the spring portion 23b.

[0079] (Other implementation methods)

[0080] The above-described embodiments are examples of preferred embodiments of the present invention, but are not limited thereto. Various modifications can be made without changing the spirit of the present invention.

[0081] In the above embodiment, the leaf spring 13 can also be arranged on the spring mounting portion 4d such that the curved plate portion 13d becomes the lower end of the leaf spring 13. That is, the lower end of the first flat plate portion 13b and the lower end of the second flat plate portion 13c are connected by the curved plate portion 13d, and the shape of the leaf spring 13 when viewed from the right oblique front side (or from the left oblique rear side) can also be U-shaped. However, as in the above embodiment, when the leaf spring 13 is arranged in the spring mounting portion 4d such that the shape of the leaf spring 13 when viewed from the vertical direction is U-shaped, the leaf spring 13 can be miniaturized in the vertical direction, and therefore, the actuator 1 can be miniaturized in the vertical direction.

[0082] In the above embodiment, the leaf spring 13 may be mounted on the movable body 3, and the ball holding member 12 may be mounted on the fixed body 4. In this case, the ball 11 is held on the fixed body 4. Furthermore, in this case, the contact surface 13a of the leaf spring 13 contacts the portion of the ball 11 exposed outside the ball holding member 12 from the inside of the first orthogonal direction with a predetermined contact pressure. Alternatively, in the above modified example, the connecting portion 23c of the leaf spring 23 may be fixed to the movable body 3, and the ball holding member 12 may be mounted on the fixed body 4. In this case, the contact surface 23a of the leaf spring 23 contacts the portion of the ball 11 exposed outside the ball holding member 12 from the inside of the first orthogonal direction with a predetermined contact pressure.

[0083] In the above embodiments, the actuator 1 can also be used in a device other than a projector. In this case, optical elements other than the optical glass 2 can also be held on the movable body 3. For example, optical elements such as lenses, prisms, reflectors, or optical filters can also be held on the movable body 3. In addition, an imaging element can also be held on the movable body 3. When an imaging element is held on the movable body 3, the actuator 1 is, for example, mounted on a camera. The term "optical elements" in this specification also includes imaging elements.

[0084] Symbol Explanation

[0085] 1 Actuator

[0086] 2. Optical glass (optical elements)

[0087] 3. Movable bodies

[0088] 3C protrusion

[0089] 3d concavity

[0090] 4. Fixing body

[0091] 5. Magnetic drive mechanism

[0092] 6 fulcrum part

[0093] 11 spheres

[0094] 12 sphere retaining components

[0095] 12a cylinder section

[0096] 12b bottom

[0097] 12c through hole

[0098] 13 Leaf Springs (Spherical Support Component)

[0099] 13a contact surface

[0100] 23 leaf springs

[0101] 23a contact surface

[0102] 23b Spring section (spherical support component)

[0103] 23c Connector

[0104] 23d ribs

[0105] V is the first orthogonal direction.

Claims

1. An actuator, characterized in that, It comprises: a movable body that holds optical elements; a fixed body formed in the shape of a frame with the movable body disposed on its inner periphery, and holding the movable body so as to be rotatable; a magnetic drive mechanism that rotates the movable body in the direction in which the movable body is inclined relative to the fixed body; and a fulcrum portion that serves as a fulcrum for the rotation of the movable body relative to the fixed body. The fulcrum portion includes: a ceramic sphere; a sphere retaining member mounted on either the movable body or the fixed body and used to retain the sphere; and a sphere support member having a concave curved contact surface that contacts a portion of the sphere with a predetermined contact pressure, and mounted on the other of the movable body or the fixed body. The sphere retaining member is formed as a bottomed cylindrical shape, which has a cylindrical portion and a bottom connected to one end of the cylindrical portion. The sphere is disposed on the inner circumferential side of the cylindrical portion. A through hole is formed at the bottom, which allows a portion of the sphere disposed on the inner circumferential side of the cylindrical portion to be positioned outside the sphere retaining member. The contact surface contacts a portion of the ball disposed outside the ball retaining member.

2. The actuator according to claim 1, characterized in that, The optical elements are formed in a flat plate shape. The fulcrum is located on both ends of the movable body in a first orthogonal direction orthogonal to the thickness direction of the optical element.

3. The actuator according to claim 2, characterized in that, The ball retaining component is mounted on the movable body. The spherical support component is installed on the fixed body. The movable body has protrusions on both sides that protrude toward the first orthogonal direction and are inserted into the cylindrical portion. A recess is formed on the front end face of the protrusion, where a portion of the sphere is disposed. The contact surface contacts a portion of the sphere from the outside of the first orthogonal direction.

4. The actuator according to claim 2 or 3, characterized in that, The spherical support component is a U-shaped leaf spring. The leaf spring has a U-shaped form when viewed from the thickness direction of the optical element.

5. The actuator according to claim 2 or 3, characterized in that, The device includes a leaf spring having ball support members respectively disposed at both ends of the movable body in the first orthogonal direction and a flat plate-shaped connecting portion connecting the two ball support members. The connecting part is formed in the shape of a frame and is fixed on one side of the optical element in the thickness direction of the movable body or the fixed body.

6. The actuator according to claim 5, characterized in that, The spherical support component has reinforcing ribs formed on it.

Images