JP2008275986A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always stably maintain a face contact between the oscillation member and the contact member of an oscillation-type linear actuator. <P>SOLUTION: Pressure contact faces 48a and 51a between the oscillator 48 and slider 51 of the oscillation-type linear actuator are arcuate or spherical. By making these arcuate or spherical parts come into contact with each other, even if their contact faces rotate in the direction of an optical axis or in a direction perpendicular to the optical axis, the arcuate or spherical parts come into contact with each other, thereby changes in the configuration for contact are prevented and stable contact is maintained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens barrel having a drive source for driving a lens in the optical axis direction, and in particular using a vibration type linear actuator as the drive source.

  As an optical device, for example, as in Patent Document 1, a device using a vibration type linear actuator as a driving source for driving a lens is known. In the optical device disclosed in Patent Document 1, a vibration type linear actuator is configured by a vibration member that generates vibration by an electro-mechanical energy conversion action and a contact member that contacts the vibration member.

  Then, the vibration member is fixed to the lens holding member, the contact member is fixed to the fixing member of the lens barrel, and the driving vibration is excited in the vibration member, thereby moving the lens holding member together with the vibration member. Alternatively, the lens holding member is moved together with the contact member by fixing the contact member to the lens holding member, fixing the vibration member to the fixing member of the lens barrel, and exciting drive vibration in the vibration member.

  FIG. 17 is a configuration diagram of the vibration type linear actuator disclosed in Patent Document 1. In (a) to (d), the lens holding frame 1 holds the lens, and the guide bar 2 holds the lens holding frame 1 on the optical axis. It is guiding in the direction. Further, the support portion 3 supports the vibration member 4, and the contact member 5 is pressed against the vibration member 4. For example, a biasing member 6 using a spring generates a pressure contact force between the vibration member 4 and the contact member 5.

  On the other hand, in FIG. 18, the lens holding frame 11 holds the lens, and the guide bush 12 is attached to the lens holding frame 11 and engages with the guide bar 13 so as to be movable in the optical axis direction. The vibrator support frame 14 is provided on the guide bush 12, and the support portions 15 a and 15 b support the vibration member 16. Further, the contact member 17 is fixed to the lens barrel body 18, and the spring 19 generates an urging force that presses the vibration member 16 against the contact member 17.

Japanese Patent Laid-Open No. 10-90584

  As shown in FIGS. 17A and 17B, when the vibration member 4 or the contact member 5 is supported only by the biasing member 6, the pressure contact between the vibration member 4 and the contact member 5 is ensured. However, since there is no configuration for supporting the vibrating member 4 or the contact member 5 in the optical axis direction, the urging member 6 is deformed in the driving direction when the lens is driven, and the driving position accuracy of the lens holding frame 1 is deteriorated.

  In addition, as shown in the cross-sectional views of the optical apparatus in FIGS. 17C and 17D and FIG. 18, the vibrating members 4 and 16 are movable only in the direction perpendicular to the pressure contact surface by the support portions 3 or 15a and 15b. Is held in the correct state. Therefore, when the guide bars 2 and 13, the support portions 3, 15 a and 15 b, and the contact members 5 and 17 are attached with an inclination, the vibration members 4 and 16 and the contact members 5 and 17 are so-called point contact or line contact. It becomes a state.

  Thereby, only a driving force smaller than the driving force originally obtained by the surface contact between them can be obtained.

  FIG. 19 shows a state in which the previous contact members 5 and 17 are inclined around the optical axis direction, and the configuration of the slider 21 as the contact member and the vibrator 22 as the vibration member when the pressure contact surface is a plane is shown in FIG. It is explanatory drawing seen from the direction. The slider 21 has a flat pressing surface, L is the width of the slider pressing surface, and φ is the relative inclination angle between the pressing surface of the slider 21 and the pressing surface of the vibrator 22.

  FIG. 19A shows a case where φ = 0. When the pressure surface of the slider 21 is a flat surface, the pressure contact surfaces of the slider 21 and the vibrator 22 are in plane contact, so that the pressure contact force is evenly distributed and the inherent performance of the vibration type linear actuator can be extracted. .

  Further, the durability of the vibration type linear actuator greatly depends on the pressure contact stress between the pressure contact surfaces of the vibrator 22 and the slider 21. As described above, the vibration type linear actuator performs friction drive by the elliptical motion generated on the pressure contact surface of the vibrator 22 and the pressure contact force between the slider 21 and the vibrator 22. At this time, wear occurs on the pressure contact surfaces of the slider 21 and the vibrator 22, and the degree of wear is a major factor that determines the durability. If the stress between the slider 21 and the vibrator 22 is uniform and appropriate, the vibration actuator can exhibit sufficient durability.

  However, in an actual product, the slider 21 and the vibrator 22 may be attached with a relative inclination angle φ as shown in FIG. 19B due to manufacturing variations, assembly errors, and the like. In this case, only the edge of the slider 21 is in contact with the vibrator 22, and a sufficient frictional force cannot be obtained between the slider 21 and the vibrator 22, so that the performance of the vibration type linear actuator is deteriorated. .

  An object of the present invention is to provide a lens barrel that can carry out lens driving in which the pressing force in the contact state between the vibrating member and the contact member is always stable, has excellent durability, and can be reduced in size compared to the conventional one. is there.

  In order to achieve the above object, the technical feature of the lens barrel according to the present invention is that, in the vibration type actuator for moving the lens, there is one contact portion of the vibrator, and a pressure contact with the axis of the contact portion in the moving direction. The cross section on the plane including the direction axis is an arc shape, and the cross section on the plane perpendicular to the axis of the moving direction is an arc shape on the contact portion of the sliding member that contacts the contact portion of the vibrator It is in.

  The technical feature of the lens barrel according to the present invention is that in the vibration type actuator for moving the lens, the contact portion of the vibrator is one place, the contact portion is spherical or elliptical, and the contact portion of the vibrator The contact portion of the sliding member that comes into contact with the flat surface or the cross section of the surface perpendicular to the axis in the moving direction has an arc shape.

  According to the lens barrel of the present invention, even if the relative positions and inclinations of the vibration member and the contact member change, the pressure contact surfaces of these members are always in contact with the vibration member by making them arc-shaped or spherical. The pressure contact surface of the member comes into contact with the arc-shaped surface, and a good surface contact state is maintained. Accordingly, an output corresponding to the original performance of the vibration type linear actuator can be stably extracted.

  The present invention will be described in detail with reference to the embodiments shown in FIGS.

  FIG. 1 is a cross-sectional view of the lens barrel of the first embodiment, and FIG. 2 is an exploded perspective view of the lens barrel. 3 is a cross-sectional view perpendicular to the optical axis of the first vibration type linear actuator constituting the lens barrel, and FIG. 4 is a cross-sectional view parallel to the optical axis. FIG. 5 is a cross-sectional view perpendicular to the optical axis of the second vibration type linear actuator constituting the lens barrel, and FIG. 6 is a cross-sectional view parallel to the optical axis.

  In the lens barrel, a first lens unit 31, a second lens unit 32, a third lens unit 33, and a fourth lens unit 34 are arranged in order from the object side, and the second lens unit 32 and the third lens unit 33 are arranged. A light amount adjustment unit 35 is disposed between them. The first lens unit 31 and the third lens unit 33 are fixed, the second lens unit 32 moves in the optical axis direction for zooming, and the fourth lens unit 34 corrects and focuses the image plane variation accompanying zooming. Move along the optical axis for adjustment.

  The first lens unit 31 is held by a first lens holding member 36, and the first lens holding member 36 is fixed to the rear barrel 38 by three screws 37. The rear barrel 38 holds an image sensor and a low-pass filter (LPF), which will be described later, and is fixed to a camera body (not shown). Guide bars 39 and 40 are held between the rear barrel 38 and the first lens holding member 36 in parallel to the optical axis direction.

  The second lens unit 32 is held by a second lens holding member 41, and a mask 42 for cutting unnecessary light is fixed to the second lens holding member 41. The second lens holding member 41 engages with the guide bar 39 in the engaging portion 41a and is guided in the optical axis direction, and engages with the guide bar 40 in the engaging portion 41b and rotates around the guide bar 39. It is blocked.

  The third lens unit 33 is held by a third lens holding member 43, and the third lens holding member 43 is fixed to the rear barrel 38 by screws 44. The fourth lens unit 34 is held by a fourth lens holding member 45. The fourth lens holding member 45 is engaged with the guide bar 40 in the engaging portion 45a and guided in the optical axis direction, and the guide bar is engaged in the engaging portion 45b. 39 and is prevented from rotating around the guide bar 40.

  The light amount adjustment unit 35 has an outer shape that is longer in the vertical direction than the left and right direction when viewed from the optical axis direction. The light amount adjustment unit 35 is fixed to the rear barrel 38 by screws 46. Although not shown in detail, the light amount adjusting unit 35 is a so-called guillotine type diaphragm that increases or decreases the aperture diameter by moving a pair of diaphragm blades in the vertical direction by a lever rotated by a stepping motor.

  The slider 48, which is a sliding member, is configured by joining a magnet and an elastic member, and the pressure contact surface 48a of the slider 48 has an arc shape in a cross section centering on an axis parallel to the optical axis. A bar 49 is sandwiched and fixed between the first lens holding member 36 and the rear lens barrel 38, and a slider holder 50 is fitted to the bar 49 to hold the slider 48.

  The vibrator 51 includes an electro-mechanical energy conversion element and a plate-like elastic member whose vibration is excited by the electro-mechanical energy conversion element, and is fixed to the bases 41c and 41d of the second lens holding member 41 by bonding or the like. ing. The vibrator 51 is a ferromagnetic body, and is formed at one position in the optical axis direction of the vibrator 51 and the pressure contact surface 48a of the slider 48, which is an elastic member, by being attracted to the magnet of the slider 48 and perpendicular to the optical axis. An arc-shaped press contact surface 51a centering on the axis is elastically pressed.

  In the first vibration type linear actuator constituted by the slider 48 and the vibrator 51, the electromechanical energy conversion element receives a frequency signal composed of two pulse signals or alternating signals having different phases via the flexible wiring board 52. Entered. As a result, the vibrator 51 is excited, an elliptical motion is generated on the pressure contact surface 51a, and a driving force in the optical axis direction is generated on the pressure contact surface 48a of the slider 48 by the frictional force generated by the pressure contact force between the slider 48 and the vibrator 51. To do.

  A scale 53 is fixed by bonding or the like in a groove 41e formed in the second lens holding member 41, and the scale 53 detects a movement amount (position) of the second lens holding member 41 in the optical axis direction. The light projecting / receiving element 54 projects light on the scale 53, receives light reflected from the scale 53, and detects the amount of movement of the second lens holding member 41. The scale 53 and the light projecting / receiving element 54 constitute a first linear encoder as a position detector. The flexible wiring board 55 inputs and outputs signals to the light projecting / receiving element 54, and the flexible wiring board 55 is fixed to the first lens holding member 36 by screws 56.

  The first linear encoder includes a guide bar 39, a first vibration type linear actuator including a slider 48 and a vibrator 51, a scale 53 and a light projecting / receiving element 54. As shown in FIG. 3, the first linear encoder is disposed close to the right side surface of the light amount adjustment unit 35 when viewed from the front direction of the optical axis. The first vibration type linear actuator and the first linear encoder are arranged adjacent to the guide bar 39 so as to sandwich the guide bar 39 in the vertical direction.

  The slider 57 is configured by joining a magnet and an elastic member, and the pressure contact surface 57a of the slider 57 has an arc shape centering on an axis parallel to the optical axis direction. The elastic member of the vibrator 58 is a ferromagnetic body, and by pulling it with the magnet of the slider 57, an axis perpendicular to the optical contact axis 57a of the slider 57 and the optical axis formed at one place in the optical axis direction of the vibrator 58 is provided. A pressure contact surface 58a, which is a surface including an axis in the pressure contact direction as a center, is elastically pressed.

  In the second vibration type linear actuator constituted by the slider 57 and the vibrator 58, two pulse signals or alternating signals having different phases are input to the electromechanical energy conversion element via the flexible wiring board 59.

  As a result, the vibrator 58 is excited, and an elliptical motion is generated on the pressure contact surface 58a, which is a surface including the axis in the pressure contact direction. The friction force generated by this motion and the pressure contact force between the slider 57 and the vibrator 58 causes the slider 57 to move. A driving force in the optical axis direction is generated on the pressure contact surface 57a.

  The vibrator 58 is fixed to the vibrator holder 60 by adhesion or the like, and the vibrator holder 60 is fixed to the positioning pins 60a and 60b. An actuator cover 61 is fixed to the rear barrel 38 with retaining screws 62 and 63, and a bar 64 is held parallel to the optical axis direction by the rear barrel 38 and the actuator cover 61. The vibrator holder 60 is fitted to the bar 64, is rotatably held around the bar 64, and is restricted in the optical axis direction by a stopper of the rear barrel 38 (not shown).

A scale 65 is fixed in the groove 45 c formed in the fourth lens holding member 45 by adhesion or the like, and the scale 65 detects the movement amount (position) of the fourth lens holding member 45.
The light projecting / receiving element 66 projects light onto the scale 65, receives light reflected from the scale 65, and detects the amount of movement of the fourth lens holding member 45.

  The scale 65 and the light projecting / receiving element 66 constitute a second linear encoder as a detector. A flexible wiring board 67 for inputting / outputting signals to / from the light projecting / receiving element 66 is fixed to the rear barrel 38 with screws 68.

  The second linear encoder includes a guide bar 40, a second vibration type linear actuator including a slider 57 and a vibrator 58, a scale 65, and a light projecting / receiving element 66. The second linear encoder is disposed close to the left side surface of the light amount adjusting unit 35 as shown in FIG. 3 when viewed from the front side of the optical axis.

  Further, the second vibration type linear actuator and the second linear encoder are arranged adjacent to the guide bar 40 so as to sandwich the guide bar 40 in the vertical direction.

  Further, with respect to the guide bar 39, the first vibration type linear actuator, and the first linear encoder, the guide bar 40, the second vibration type linear actuator, and the second linear encoder are vertically moved through the center of the optical axis. It is arrange | positioned so that it may become symmetrical with respect to the axis | shaft extended in this.

  FIG. 7 is a block circuit configuration diagram of the photographing apparatus of the present embodiment. The output of the image sensor 71 composed of a CCD sensor, a CMOS sensor or the like that receives incident light passing through the first to fourth lens units 31 to 34 is connected to the camera signal processing circuit 72, and the output of the camera signal processing circuit 72 is AE. The gate 73 and the AF gate 74 are connected. The output of the AE gate 73 is connected to a control circuit 75 comprising a CPU or the like, and the output of the AF gate 74 is connected to the control circuit 75 via an AF signal processing circuit 76 for processing an AF signal for AF (autofocus). ing.

  The control circuit 75 is connected to outputs of a second lens encoder 77 that detects the position of the second lens unit 32 in the optical axis direction and an output of a fourth lens encoder 78 that detects the position of the fourth lens unit 34 in the optical axis direction. . The control circuit 75 is connected to the output of a diaphragm encoder 79 that detects the aperture diameter of the light quantity adjustment unit 35, and the control circuit 75 is further connected to a zoom switch 80 and a zoom tracking memory 81.

  The output of the control circuit 75 is connected to the first vibration type linear actuator 82 that is the drive source of the second lens holding member 41 and the second vibration type linear actuator 83 that is the drive source of the fourth lens holding member 45. Yes. Further, the output of the control circuit 75 is connected to a meter 84 that drives the light amount adjustment unit 35.

  The second lens encoder 77 is a first linear encoder including the scale 53 and the light projecting / receiving element 54, and the fourth lens encoder 78 is a second linear encoder including the scale 65 and the light projecting / receiving element 66. These encoders detect the relative positions, which are the movement amounts of the second lens unit 32 and the fourth lens unit 34 from the reference position in the optical axis direction.

  Note that a magnetic encoder other than the optical encoder may be used as the encoder, or the absolute position may be detected using an electrical resistance. The diaphragm encoder 79 uses, for example, a method of detecting the rotational positional relationship between the rotor of the meter 84 and the scale by using a hall element provided inside the meter 84.

  The control circuit 75 is a controller that controls the operation of the photographing position, and the camera signal processing circuit 72 performs signal processing such as predetermined amplification and gamma correction on the output from the image sensor 71. The contrast signal of the video signal that has undergone these processes is supplied to the AE gate 73 and the AF gate 74. The AF signal processing circuit 76 extracts a high-frequency component of the video signal and generates an AF evaluation value signal. Each of the AE gate 73 and the AF gate 74 extracts an optimum signal for exposure control and focusing, sets a range from the video signal of the entire screen, and the sizes of the gates 73 and 74 are variable, There may be more than one.

  The zoom tracking memory 81 stores position information of the fourth lens unit 34 corresponding to the subject distance and the position of the second lens unit 32 at the time of zooming. Note that a memory in the control circuit 75 may be used as the zoom tracking memory 81.

  In the above configuration, when the photographer operates the zoom switch 80, the control circuit 75 controls the first vibration type linear actuator 82 to drive the second lens unit 32. Accordingly, the target drive position of the fourth lens unit 34 is calculated based on the information in the zoom tracking memory 81 and the current position of the second lens unit 32 obtained from the detection result of the second lens encoder 77.

  Then, the second vibration type linear actuator 83 is controlled so as to drive the fourth lens unit 34 to the target drive position. Whether or not the fourth lens unit 34 has reached the target drive position is determined by whether or not the current position of the fourth lens unit 34 obtained from the detection result of the fourth lens encoder 78 matches the target drive position. Is determined by

  In autofocus, the control circuit 75 searches for a position where the AF evaluation value obtained by the AF signal processing circuit 76 shows a peak, and the second vibration type linear actuator 83 that drives the fourth lens unit 34. To control.

  Further, in order to obtain an appropriate exposure, the control circuit 75 makes the average value of the luminance signal passed through the AE gate 73 become a predetermined value, that is, so that the output of the aperture encoder 79 becomes a value corresponding to the predetermined value. The aperture diameter is controlled by controlling the meter 84 of the light quantity adjustment unit 35.

  FIG. 8 is an explanatory diagram of a slider used in the first embodiment. The slider 101 is a simplified illustration of the sliders 48 and 57 of the first embodiment, and the pressing surface is arcuate with O at the center. The width of the slider 101 is L, the edge portions of the pressure surface 101c are 101a and 101b, a line drawn from the midpoint 101d of the pressure surface 101c of the slider 101 to the center O of the arc, and the edge portion 101a to the center O of the arc. Let θ be the angle formed by the drawn straight line. At this time, there is a relationship of 2R / L = sin θ among the radius R, width L, and angle θ of the arc.

  FIG. 9 is an explanatory view of the configuration of the slider 101 and the vibrator 102 as viewed from the moving direction. φ is an inclination angle due to a manufacturing error between the slider 101 and the vibrator 102, and an angle formed by a line segment drawn from the center O of the arc to the midpoint of the pressing surface 101c and a perpendicular drawn from the midpoint of the pressing surface 101c. Show.

FIG. 9A shows a case where φ = 0, and in this case, the vibrator 102 and the slider 101 are press-contacted at the midpoint of the pressurization surface 101c which is a surface including the axis in the press-contact direction.
FIG. 9B shows the case of φ ≦ θ, and the contact point is located on an arc deviated by φ from the midpoint of the pressing surface 101c, and the same contact state as in FIG. 9A can be obtained. Can do.

  FIG. 9C shows a case where φ> θ, and the slider 101 and the vibrator 102 are press-contacted by the edge portion 101a. In this state, a sufficient frictional force cannot be obtained between the slider 101 and the vibrator 102, and both the driving performance and durability of the vibration type linear actuator are lowered.

  9A and 9B, the contact state between the slider 101 and the vibrator 102 is a contact between the arc portions, but since the slider 101 and the vibrator 102 have elasticity, they are not point contacts. Surface contact. Therefore, if the state shown in FIG. 9A or 9B (φ ≦ θ), the vibration type linear actuator can be operated satisfactorily. Here, the contact area increases as the radius R, which is the curvature of the arc, increases, and both drive characteristics and durability can be improved.

  On the other hand, when the slider 101 is constituted by a cylinder, the restriction on the width of the slider 101 is reduced, and the driving characteristics and durability are lowered. Accordingly, it is desirable here to set the radius R as large as possible within the range of possible tilt of the slider 101.

  Furthermore, when the applied pressure between the vibrator 102 and the slider 101 is a magnet, if the radius R is increased, the gap with the vibrator 102 is increased at the edge portions 101a and 101b, and the applied pressure is reduced. From this, it can be said that a larger radius R is desirable.

  FIG. 10 is a graph showing the relationship between the R / L ratio and θ. A relative tilt angle between the vibrator 102 and the slider 101 caused by a manufacturing error or an assembly error is expected to be about 2.5 degrees. The value of the angle θ needs to be set to be greater than the expected inclination of the slider 101 in order to maintain contact at the arc portion of the slider 101. Therefore, it is desirable to set R / L so that the angle θ is 2.5 degrees or more. When R / L = 10, the angle θ is preferably set to R / L ≦ 10 from 2.87 degrees. Since the width L cannot be more than twice the radius R, the lower limit of R / L is 0.5.

  In addition, even when rotated in a direction perpendicular to the optical axis, the contact portion of the vibrator 102 has an arc shape in the same manner as described above, so that the contact state does not change and the driving characteristics and durability characteristics are not deteriorated. .

  11 and 12 are explanatory views of the first vibration type linear actuator 82. FIG. FIG. 11 shows a state in which the slider 48 and the vibrator 51 are attached without deviation, FIG. 12 shows a state in which an axis parallel to the moving direction is displaced, and (a) is a cross-sectional view seen from the axial direction of the slider 48. b) is a cross-sectional view seen from a direction orthogonal to the axis of the slider 48. Even when a deviation in inclination with respect to an axis parallel to the moving direction occurs on one of the pressure contact surfaces of the slider 48 and the vibrator 51 due to a manufacturing error or the like, the pressure contact surface 48a has an arc shape. There is no change in the shape of the contact point, and performance degradation can be prevented.

  Even when a displacement in the pressure contact surface direction occurs, the pressure contact position can be adjusted by rotating the slider holder 50 around the bar 49. Even when a displacement of inclination with respect to an axis perpendicular to the moving direction and parallel to the contact surface is generated on any pressure contact surface of the slider 48 and the vibrator 51, the pressure contact surface 51a of the vibrator 51 has an arc shape. There is no change in the shape of the contact point of the vibrator 51, and performance degradation can be prevented. As described above, since the structure in which the contact surface of the slider 48 and the vibrator 51 is parallel is simplified, the vibration type linear actuator 82 can be held in a small size, and the lens barrel can be downsized.

  In the above configuration, the slider 48 is configured by using a magnet, and obtains a pressure contact force necessary to generate a driving force as a vibration type linear actuator by attracting the vibrator 51. For this reason, the reaction force of the pressure contact force does not act on the second lens holding member 41. Thereby, the frictional force generated in the engaging portions 41a and 42b of the second lens holding member 41 with the guide bars 39 and 40 does not increase, and the driving load due to friction does not increase. Therefore, it is possible to use a small vibration linear actuator with low output, and as a result, it is possible to reduce the size of the lens barrel.

  In addition, since a large pressure contact force does not act on the second lens holding member 41, the frictional force generated at the engaging portions 41a and 42b of the second lens holding member 41 with the guide bars 39 and 40 does not increase. Therefore, wear due to friction between the engaging portions 41a and 42b and the guide bars 39 and 40 can be reduced, and the second lens holding member 41 can be precisely driven.

  13 and 14 are explanatory views of the second vibration type linear actuator 83. FIG. 13 shows a state in which the slider 57 and the vibrator 58 are attached without deviation, FIG. 14 shows a state in which the slider 57 is displaced by an axis parallel to the moving direction, and FIG. b) is a cross-sectional view seen from a direction orthogonal to the axis of the slider 57. FIG.

  When a rotational shift occurs around the axis parallel to the moving direction between the slider 57 and the vibrator 58 due to a manufacturing error or the like, the contact surface 57a of the slider 57 has an arc shape. Although it changes, since the shape of the contact point is not changed, performance deterioration can be prevented. Even if any of the slider 57 and the vibrator 58 is displaced in the direction perpendicular to the pressure contact surface, the displacement is adjusted by rotating the vibrator holder 60 around the bar 64, so that the slider 57 and the vibrator 58 are adjusted. 58 pressure contact states can be maintained.

  Similarly, even when a rotational deviation about an axis perpendicular to the moving direction and parallel to the pressure contact surface occurs between the slider 57 and the vibrator 58, the pressure contact surface 58a of the vibrator 58 has an arc shape. Although the contact point changes, there is no change in the shape of the contact point, so that performance deterioration can be prevented. Since the structure in which the contact surfaces of the slider 57 and the vibrator 58 are parallel is simplified, the second vibration type linear actuator 83 can be held in a small size, and the lens barrel can be downsized.

  The magnitude of the inclination of the contact surface between the slider 57 and the vibrator 58 differs between the moving direction and the direction perpendicular to the moving direction and parallel to the contact surface. The larger the arc of the contact surface, the better the arc of the slider 57 and the vibration. It is desirable to change the size of the arc of the child 58. Although it is possible to make the slider 57 flat and the pressure contact surface 58a of the vibrator 58 to be elliptical, by dividing the slider 57 and the vibrator 58 into a circular arc in the moving direction and a circular arc perpendicular to the moving direction, 2 The size of one arc can be easily changed. Since the attachment length is long in the movement direction, the inclination error in the movement direction is usually smaller than the direction perpendicular to the movement direction, and the arc can be enlarged.

  In the second vibration type linear actuator 83, the slider 57 is configured by using a magnet, and the pressure contact force necessary for generating the driving force is obtained by attracting the vibrator 58. The force does not act on the fourth lens holding member 45. As a result, the frictional force generated in the engaging portions 45a and 45b of the fourth lens holding member 45 with the guide bars 39 and 40 does not increase, and the driving load due to friction does not increase. Therefore, it is possible to use a small vibration linear actuator with low output, and as a result, it is possible to reduce the size of the lens barrel.

  Further, since a large pressure contact force does not act on the fourth lens holding member 45, the frictional force generated in the engaging portions 45a and 45b of the fourth lens holding member 45 with the guide bars 39 and 40 does not increase. Wear due to friction between the engaging portions 45a and 45b and the guide bars 39 and 40 can also be reduced. Further, the minute driving of the fourth lens holding member 45 can be performed accurately.

  In this embodiment, when viewed from the optical axis direction, as shown in FIG. 5, the guide bar 39, the first vibration type linear actuator 82, and the first linear encoder are on the plane closest to the optical axis of the light amount adjusting unit 35. It arrange | positions so that it may approach along the right side surface which is one. A first vibration type linear actuator 82 and a first linear encoder are arranged adjacent to the upper and lower sides of the guide bar 39.

  Further, as shown in FIG. 5, the guide bar 40, the second vibration type linear actuator 83, and the second linear encoder are located on the plane closest to the optical axis in the light amount adjustment unit 35 as viewed from the optical axis direction. It arrange | positions along the left side which is one. A second vibration type linear actuator 83 and a second linear encoder are arranged adjacent to the upper and lower sides of the guide bar 40.

  Accordingly, the lens barrel has the light amount adjustment unit 35, the two vibration linear actuators for driving the second and fourth lens holding members 41 and 45, the two guide bars, and the two linear encoders. It can be configured in a small size.

  Further, since the sliders 48 and 57 are disposed adjacent to the guide bars 39 and 40, respectively, the second and fourth lens holding members 41 and 45 can be driven smoothly. Moreover, since the scales 53 and 65 are disposed adjacent to the guide bars 39 and 40, respectively, the scale is based on the back of the engaging portions 41a, 42b, 45a and 45b of the second and fourth lens holding members 41 and 45. Positions can be accurately detected with little displacement of 53 and 65.

  In the present embodiment, the case where the vibrator 51 is provided on the second lens holding member 41 and the slider 48 is provided on the fixed portion of the lens barrel has been described for the first vibration type linear actuator 82. However, the vibrator 51 and its holding mechanism may be provided in the fixed portion, and the slider 48 and its holding mechanism may be provided in the second lens holding member 41.

  In the second vibration type linear actuator 83, the case where the slider 57 is provided on the third lens holding member 45 and the vibrator 58 is provided on the fixed portion of the lens barrel has been described. However, the slider 57 and its holding mechanism may be provided in the fixed portion, and the slider 57 and its holding mechanism may be provided in the second lens holding member 41.

  In the above-described embodiment, the first and second vibration type linear actuators 82 and 83 both have a slider made of a magnet to generate a pressure contact force. However, the present invention can also be configured for a vibration type actuator that performs pressure contact with an elastic member such as a spring member.

  FIG. 15 is a perspective view seen from the contact surface direction of the vibrator of the second embodiment. 16A and 16B are configuration diagrams of the slider and the vibrator. FIG. 16A is a diagram viewed from the moving direction, and FIG. 16B is a diagram viewed from the direction perpendicular to the moving direction.

  The slider 111 has a flat contact surface, and the vibrator 112 has a pressure contact surface 112a part of a spherical surface. When the pressure contact surface 111a, which is a surface including the axis in the pressure contact direction of the slider 111, and the pressure contact surface of the vibrator 112 are inclined, the pressure contact surface 112a of the vibrator 112 is spherical, so that the shape of the contact point is changed. And performance degradation can be prevented.

  In this case, one of the vibrator 112 and the slider 111 is attached to the lens holding member, the other is fixed to the fixing portion, and the lens holding member is moved. Further, the pressure contact surface 112a of the vibrator 112 is a part of a spherical shape, and the spherical shape can be easily created, but may be an elliptical shape.

  In the first and second embodiments, the lens-integrated photographing apparatus has been described, but the present invention can also be applied to an optical apparatus having an interchangeable lens that can be attached to and detached from the photographing apparatus body. Furthermore, the present invention can be applied not only to a photographing apparatus but also to various optical devices in which a lens is driven by a vibration type linear actuator.

  The present invention is not limited to the configurations described in these embodiments, and various modifications and changes can be made to the above-described embodiments within the scope of the claims.

2 is a cross-sectional view of a lens barrel of Embodiment 1. FIG. It is a disassembled perspective view of a lens barrel. It is sectional drawing of the optical axis perpendicular | vertical direction of the lens barrel of a 1st vibration type linear actuator part. It is sectional drawing of the direction parallel to the optical axis of the lens barrel of a 1st vibration type linear actuator part. It is sectional drawing of the optical axis perpendicular direction of the lens barrel of a 2nd vibration type linear actuator part. It is sectional drawing of the direction parallel to the optical axis of the lens barrel of a 2nd vibration type linear actuator part. It is the block circuit block diagram which showed the electrical structure of the imaging device. It is the front view which looked at the slider from the moving direction. It is a block diagram of a slider and a vibrator. It is a graph showing the relationship between θ and the R / L ratio. It is explanatory drawing of a 1st vibration type linear actuator. It is explanatory drawing of a 1st vibration type linear actuator. It is explanatory drawing of a 2nd vibration type linear actuator. It is explanatory drawing of a 2nd vibration type linear actuator. FIG. 6 is a perspective view of the vibrator of Example 2 viewed from the contact surface direction. It is a block diagram of a vibrator and a slider. It is a block diagram of the vibration type linear actuator of a prior art example. It is a block diagram of the optical apparatus of a prior art example. It is operation | movement explanatory drawing of a prior art example.

Explanation of symbols

31 First lens unit 32 Second lens unit 33 Third lens unit 34 Fourth lens unit 35 Light quantity adjustment unit 36 First lens holding member 38 Rear barrel 39, 40 Guide bar 41 Second lens holding member 43 Third lens holding Member 45 Fourth lens holding member 48, 57, 101, 111 Slider 51, 58, 102, 112 Vibrator 53, 65 Scale 54, 66 Light emitting / receiving element 61 Actuator cover 71 Imaging element 75 Control circuit 82 First vibration type linear Actuator 83 Second vibration type linear actuator

Claims (6)

  In the vibration type actuator for moving the lens, there is one contact portion of the vibrator, and a cross section on a plane including the moving direction axis and the pressure contact direction axis of the contact portion is an arc shape. A lens barrel characterized in that a cross section of a contact portion of a sliding member that comes into contact with the contact portion is a circular arc in a plane perpendicular to an axis in a moving direction.   In the vibration type actuator that moves the lens, the contact portion of the vibrator is one place, the contact portion is spherical or elliptical, and the contact portion of the sliding member that contacts the contact portion of the vibrator is flat or moved. A lens barrel characterized in that a cross section of a plane perpendicular to a direction axis is an arc shape.   The width of the contact portion between the vibrator and the sliding member is L, and the radius of the arc having the moving direction as an axis is R, 0.5 ≦ R / L ≦ 10. Item 3. The lens barrel according to Item 1 or 2.   The lens barrel according to claim 1, wherein the curvature of the arc of the contact portion between the vibrator and the sliding member is different.   3. The lens barrel according to claim 1, wherein a curvature of an arc of a contact portion between the vibrator and the sliding member is larger in a direction perpendicular to the moving direction than in the moving direction.   The lens barrel according to any one of claims 1 to 5, wherein the vibrator includes a ferromagnetic body, and the sliding member includes a magnet.

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