JP2019070758A - Lens barrel and imaging device - Google Patents

Abstract

To provide a compact lens barrel that increases the degree of freedom in the amount of movement of a plurality of lenses.SOLUTION: A lens barrel comprises: a first cam member 22 that has a first cam part 22a and is rotated around the optical axis of the lens barrel to move a first lens unit L12 in the optical axis direction via the first cam part; a second cam member 22 that has a second cam part 23a and is rotated around the optical axis to move a second lens unit L13 in the optical axis direction via the second cam part; a third cam member 21 that has a third cam part 21b and a fourth cam part 21c and is rotated around the optical axis to move the first cam member and second cam member in the optical axis direction via both the third cam part and fourth cam part; a first actuator 30 that rotates the third cam member; and a second actuator 20 that rotates the first and second cam members.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a lens barrel used in an imaging device such as a digital still camera or a video camera.

  In an imaging apparatus such as a compact digital camera, a zoom type lens barrel is mounted in which the lens barrel is driven with respect to the imaging apparatus main body in a use state (power on state) of the imaging apparatus. In a conventional zoom type lens barrel, a single motor rotates a cam ring around an optical axis to move a movable barrel engaged with a cam groove formed in the cam ring and the lens inside the lens barrel from the wide-angle end Move to the end.

  In addition, a lens barrel that moves a lens so as to draw a locus different from that in zooming in an imaging mode (for example, macro mode) different from a normal mode is also used. Even when such a lens barrel is used, it is required to minimize the outer diameter of the lens barrel in order to miniaturize the digital camera. In the imaging device disclosed in Patent Document 1, a lens holding frame is formed by rotating a cam cylinder and moving a movable cylinder in the optical axis direction and a cam member provided in the movable cylinder. And a second actuator for moving in the optical axis direction.

Patent No. 5006602

  However, in the configuration of the lens barrel of the imaging device disclosed in Patent Document 1, in the imaging mode different from the above-described normal mode, a plurality of lenses are moved so as to draw different trajectories different from during zooming. Is difficult. That is, the degree of freedom of the movement amount of each lens is limited in at least one of zooming and imaging modes different from normal.

  The present invention provides a lens barrel and an imaging device which can be miniaturized while increasing the degrees of freedom of movement amounts of a plurality of lenses.

  The lens barrel as one aspect of the present invention can move a plurality of lens units in the optical axis direction. The lens barrel has a first cam portion, and is rotated about an optical axis of the lens barrel or about an axis parallel to the optical axis, thereby rotating a plurality of lens units via the first cam portion. Among them, a first cam member for moving the first lens unit in the optical axis direction, and a second cam portion, and by rotating around the optical axis, a plurality of lens units via the second cam portion And a second cam member for moving the second lens unit in the optical axis direction, a third cam portion and a fourth cam portion, and rotating about the optical axis or an axis parallel to the optical axis A third cam member for moving the first cam member and the second cam member in the optical axis direction via the third cam portion and the fourth cam portion, and The first actuator to rotate and the second to rotate the first and second cam members And having an actuator.

  An imaging apparatus provided with the above-mentioned lens barrel also constitutes another aspect of the present invention.

  According to the present invention, it is possible to realize a small-sized lens barrel having a high degree of freedom in the amount of movement of the first and second lens units and an imaging apparatus provided with the same.

Sectional drawing in the retracted state of the lens barrel which is Example 1 of this invention. FIG. 2 is a cross-sectional view of the lens barrel of Embodiment 1 in a wide state. FIG. 2 is a cross-sectional view of the lens barrel of Embodiment 1 in the tele state. FIG. 2 is a cross-sectional view of the lens barrel of Embodiment 1 in a macro state. FIG. 2 is a perspective view of the lens barrel of Example 1; FIG. 2 is an exploded view of a lens barrel of Example 1; FIG. 6 is a perspective view of a stepping motor in the lens barrel of Embodiment 1; 5 is a developed view of a second group cam cylinder and a third group cam cylinder in the lens barrel of Embodiment 1. FIG. Sectional drawing in the retracted state of the lens barrel which is Example 2 of this invention. FIG. 7 is a cross-sectional view of the lens barrel of Embodiment 2 in a wide state. FIG. 7 is a cross-sectional view of the lens barrel of Embodiment 2 in the tele state. FIG. 8 is a cross-sectional view of the lens barrel of Embodiment 2 in a macro state. FIG. 7 is a perspective view of a lens barrel of Example 2; FIG. 7 is an exploded view of a lens barrel of Example 2; FIG. 10 is a perspective view of a stepping motor in the lens barrel of Embodiment 2; FIG. 16 is a developed view of a second group cylindrical cam and a third group cylindrical cam in the lens barrel of the second embodiment. The figure which shows the structure of the imaging device which is Example 3 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The lens barrel which is Embodiment 1 of the present invention is used for a compact digital camera as an imaging device. 1, 2, 3 and 4 show the internal configurations of the lens barrel of this embodiment in the retracted state (stored state), wide state, tele state and macro state (state for macro photography), respectively. ing. FIG. 4 and FIG. 5 respectively show the lens barrel of the present embodiment as viewed obliquely and disassembled.

  The lens barrel includes an imaging optical system including a first group lens L11 as a plurality of lens units, a second group lens (first lens unit) L12, a third group lens (second lens unit) L13, and a fourth group lens L14. Have. The direction in which the optical axis (indicated by a two-dot chain line in the drawing) of the lens barrel, that is, the imaging optical system extends is called the optical axis direction, and the direction orthogonal to the optical axis is called the radial direction.

  Reference numeral 11 denotes a first group cylinder that holds the first group lens L11. One set of six cam pins 11 a disposed at the rear end of the inner peripheral surface of the first group cylinder 11 is engaged with the cam groove portion 21 a formed on the outer peripheral surface of the cam cylinder 21. In three places on the inner peripheral surface of the first group cylinder 11, rectilinear grooves 11b extending in the optical axis direction are formed. The rectilinear groove portion 11 b is engaged with the rectilinear key 24 a formed at the upper end of the outer peripheral surface of the first rectilinear barrel 24.

  Reference numeral 12 denotes a second group cylinder that holds a second group lens L12. A cam groove portion (first cam portion) formed on an inner peripheral surface of a second group cam cylinder (first cam member) 22 is formed of one set of three cam pins 12a disposed at the rear end of the outer peripheral surface of the second group cylinder 12 ) Is engaged with 22a. A straight advance key 12 b is formed at the same position as the cam pin 12 a in the second group cylinder 12. The rectilinear key 12 b is engaged with the rectilinear groove portion 24 b formed in the first rectilinear cylinder 24.

  The groove 24 c formed above the outer peripheral surface of the first straight barrel 24 is engaged with the three projections 22 b formed above the outer peripheral surface of the second cam cylinder 22. The first straight advance barrel 24 rotatably supports the second cam cylinder 22 around the optical axis, and moves in the optical axis direction integrally with the second cam cylinder 22. One set of three cam pins 24 d disposed on the outer peripheral surface of the first straight barrel 24 is provided in a cam groove portion (third cam portion) 21 b formed on the inner peripheral surface of the cam cylinder (third cam member) 21. It is engaged.

  A third group holding frame 13 holds the third group lens L13, and one set of three cam pins 13a arranged at the rear end of the outer peripheral surface of the third group holding frame 13 is a third group cam cylinder (second cam member) It is engaged with a cam groove portion (second cam portion) 23 a formed on the inner peripheral surface of 23. A straight advance key 13 b is formed at the same position as the cam pin 13 a in the third group holding frame 13. The rectilinear key 13 b is engaged with the rectilinear groove 25 b formed in the second rectilinear cylinder 25.

  The groove 25 c formed at the rear end of the outer peripheral surface of the second straight barrel 25 is engaged with three projections 23 b formed at the rear end of the outer peripheral surface of the third cam cylinder 23. The second straight advance barrel 25 rotatably supports the third cam cylinder 23 around the optical axis, and moves integrally with the third cam cylinder 23 in the optical axis direction. A set of three cam pins 25 d disposed on the outer peripheral surface of the second straight barrel 25 is engaged with a cam groove portion (fourth cam portion) 21 c formed on the inner peripheral surface of the cam cylinder 21.

  The second cam cylinder 22, the third cam cylinder 23 and the stepping motor 20 described later are disposed radially inward of the cam cylinder 21.

  Reference numerals 14 and 15 denote an aperture unit and a shutter ND unit, respectively. The aperture unit 14 and the shutter ND unit 15 are fixed to the third group holding frame 13 by screws (not shown).

  One set of three cam pins 21 d disposed at the rear end of the outer peripheral surface of the cam cylinder 21 is engaged with the cam groove portion 26 a formed on the inner peripheral surface of the fixed cylinder 26. A set of three drive pins 21 e disposed at the rear end of the outer peripheral surface of the cam cylinder 21 penetrates the through groove 26 b formed in the fixed cylinder 26 and is a rectilinear groove 27 a formed in the inner peripheral surface of the drive cylinder 27. Is engaged. 16 is a movable cover cylinder. The movable cover cylinder 16 is fixed to the cam cylinder 21 by means not shown.

  The first straight advance barrel 24 linearly guides the first group barrel 11 and the second group barrel 12 and the second straight advance barrel 25 guides the third group holding frame 13 in the optical axis direction. The straight portion 25 e formed in the second straight barrel 25 is engaged with the straight portion 24 e formed in the first straight barrel 24. The three rectilinear keys 25 a formed at the lower end of the outer peripheral surface of the second rectilinear barrel 25 are engaged with the rectilinear groove portions 26 c formed in the inner peripheral surface of the fixed barrel 26.

  A gear portion 27 b formed at the rear end of the outer peripheral surface of the drive cylinder 27 is connected to a drive cylinder drive unit constituted by a DC motor (first actuator) 30 and a plurality of gears 29. The drive cylinder 27 is rotated about the optical axis by the output of the drive cylinder drive unit. At this time, the cam cylinder 21 receives light by the cam action between the cam pin 21 d of the cam cylinder 21 and the cam groove 26 a of the fixed cylinder 26 and the engagement between the drive pin 21 e of the cam cylinder 21 and the rectilinear groove 27 a of the drive cylinder 27. It moves in the optical axis direction while rotating around the axis.

  The first group cylinder 11 has a cam action between the cam pin 11a and the cam groove 21a of the cam cylinder 21 and a linear groove 11b (not shown) of the first group cylinder 11 and the linear movement key 24a of the first linear cylinder 24. It moves in the direction of the optical axis without rotating around the optical axis by the linear guide action of

  The first straight forward cylinder 24 has a cam action between the cam pin 24 d of the first straight forward cylinder 24 and the cam groove 21 b of the cam cylinder 21 and the straight straight portion 24 e of the first straight straight cylinder 24 and the straight straight portion 25 e of the second straight straight cylinder 25. Due to the rectilinear guide action between them, it moves in the optical axis direction without rotating around the optical axis.

  The second straight moving cylinder 25 is provided between the cam key 25 d of the second straight moving cylinder 25 and the cam groove 21 c of the cam cylinder 21 and between the straight moving key 25 a of the second straight moving cylinder 25 and the straight groove 26 c of the fixed cylinder 26. It moves in the direction of the optical axis without rotating around the optical axis by the linear guide action of

  The second group cam cylinder 22 moves in the optical axis direction integrally with the first linear movement cylinder 24 by the engagement of the projection 22 b of the second group cam cylinder 22 and the groove 24 c of the first linear groove 24.

  The third group cam cylinder 23 moves in the optical axis direction integrally with the second linear movement cylinder 25 by the engagement of the protrusion 23 b of the third group cam cylinder 23 and the groove 25 c of the second linear movement groove 25.

  A gear portion 23 d is formed at the rear end of the inner peripheral surface of the third cam cylinder 23. The gear portion 23 d is connected to a stepping motor (second actuator) 20 via a gear 20 b shown in FIG. 4. When the third group cam cylinder 23 is rotated about the optical axis by the output of the stepping motor 20, the second group cam cylinder 22 is engaged with the straight portion 22c of the second group cam cylinder 22 and the straight portion 23c of the third group cam cylinder 23. Depending on the case, it rotates integrally with the third cam cylinder 23.

  The second group cylinder 12 moves in the optical axis direction by the same amount as the movement amount of the first linear movement cylinder 24 unless the second group cam cylinder 22 is rotated. When the second group cam cylinder 22 rotates, the cam action between the cam pin 12a of the second group cylinder 12 and the cam groove 22a of the second group cam cylinder 22 and the straight advance key 12b of the second group cylinder 12 and the straight advance groove section of the first straight advance cylinder 24 It moves in the direction of the optical axis without rotating around the optical axis by the rectilinear guide action between it and 24b.

  The third group holding frame 13 is also moved in the optical axis direction by the same amount as the movement amount of the second linear movement cylinder 25 unless the third group cam cylinder 23 is rotated. When the third group cam cylinder 23 rotates, the third group holding frame 13 receives a cam action between the cam pin 13a and the cam groove 23a of the third group cam cylinder 23, and the rectilinear key 13b of the third group holding frame 13 and the second straight cylinder Due to the rectilinear guide action between the rectilinear groove 25 and the rectilinear groove 25b, it moves in the optical axis direction without rotating around the optical axis.

  The imaging element S1 and the optical filter F1 are held by the fixed ground plane 28. The imaging element S1 is a photoelectric conversion element such as a CCD sensor or a CMOS sensor. The optical filter F1 has an infrared cut function and the like.

  Next, the operation of the lens barrel configured as described above will be described. The operation of the lens barrel is controlled by a camera microcomputer (hereinafter referred to as a camera microcomputer) 60 as control means shown in FIG.

  A drive signal is input from the camera microcomputer 60 to the DC motor 30 in order to make the lens barrel from the retracted state shown in FIG. 1 through the wide state shown in FIG. 2 to the tele state shown in FIG. When the DC motor 30 is driven accordingly, the rotational output is transmitted to the gear portion 27 b of the drive cylinder 27 via the plurality of gears 29. Thereby, the drive cylinder 27 rotates around the optical axis with respect to the fixed cylinder 26, and the cam cylinder 21 moves from the position in the retracted state to the position in the wide state where it protrudes forward of the fixed cylinder 26, and further to the position in the tele state. Do.

  At this time, the camera microcomputer 60 supplies a holding signal for holding the stepping motor 20 in the stop state (that is, the stop holding energization is performed). Thereby, the positions of the second cam cylinder 22 and the third cam cylinder 23 in the optical axis direction are held. Since the second cam cylinder 22 does not rotate with respect to the first rectilinear cylinder 24, the second cam cylinder 12 moves in the optical axis direction integrally with the first rectilinear cylinder 24. In addition, since the third group cam barrel 23 does not rotate with respect to the second straight barrel 25, the third group holding frame 13 moves in the optical axis direction integrally with the second straight barrel 25.

  Furthermore, the camera microcomputer 60 controls the stepping motor 20 so that the second and third group cam cylinders 23 and 33 do not rotate carelessly. Specifically, the camera microcomputer 60 controls the stepping motor 20 so as to suppress the rotation of the second and third group cam cylinders 23 and 33 through the detection means constituted by the pulse plate 20c and the photo interrupter 20d.

  As shown in FIG. 7, a pulse plate 20c is fixed to a root portion of a drive shaft 20a (not shown) of the stepping motor 20. The pulse plate 20 c rotates integrally with the gear 20 b of the stepping motor 20. The light transmitting portion and the light shielding portion of the pulse plate 20c are detected by two photo interrupters 20d, and two detection pulse signals generated thereby are input to the camera microcomputer 60. The two detection pulse signals have a phase difference with each other. The camera microcomputer 60 detects the rotational direction (that is, rotation) of the pulse plate 20c, that is, the second and third cam cylinders 23 and 33 in accordance with the phase difference between the two detection pulse signals. Then, when the rotation is detected, the camera microcomputer 60 controls the stepping motor 20 in the direction to return it.

  In order to change the tele state shown in FIG. 3 to the macro state shown in FIG. 4, the stepping motor 20 is driven without driving the DC motor 30, that is, without rotating the cam cylinder 21. And the third group cam cylinder 23 are rotated. Thereby, the second group cylinder 12 and the third group holding frame 13, that is, the second group lens L12 and the third group lens L13 are moved to the position in the macro state (a position different from the position after the storing operation).

  In FIG. 8, the cam groove portions 22a and 23a of the second cam cylinder 22 and the third cam cylinder 23 are expanded and shown in the circumferential direction (left and right direction in the drawing). Three cam groove portions 22a and 23a are formed in the second group cam cylinder 22 and the third group cam cylinder 23 at equal intervals in the circumferential direction. The upper side of the figure is the subject side. In FIG. 8, the positions of the cam pins 12a and 13a indicated by 1P1 and 2P1 correspond to the tele state shown in FIG. 3, and the positions of the cam pins 12a and 13a indicated by 1P3 and 2P3 correspond to the macro state shown in FIG. Further, in this embodiment, an intermediate macro state as a macro state different in magnification can be selected other than the macro state shown in FIG. 4, and in that case, the cam pins 12a and 13a are positioned at the positions shown in 1P2 and 2P2. Do.

  In this embodiment, during the retraction operation (storage operation) and during zooming between the wide state and the tele state, the second group and third group cam cylinders 22 and 23 are not rotated, and the second group is moved via the DC motor 30. And the interval D1 in the optical axis direction between the third group cam cylinders 22 and 23 is changed. As a result, the second and third lens units L12 and L13 are moved.

  Further, at the time of transition from the tele state to the macro state, the second cam cylinder 22 and the third cam cylinder 23 are rotated via the stepping motor 20 to move the second lens L12 and the third lens L13. With this configuration, the second and third lens groups L12 and L13 are rotated as an integrally formed component of the second and third lens group cams 22 and 23 (that is, a component without the distance D1 in the optical axis direction). As compared with the case of driving, it is possible to improve the freedom of the moving amount of the second and third lens units L12 and L13. The second and third lens groups L12 and L13 are equal to the combined lift amount of the lift amount of the cam grooves 21b and 21c of the cam cylinder 21 and the lift amounts of the cam grooves 22a and 23a of the second and third lens groups cam cylinders 22 and 23. Move in the optical axis direction.

  In the present embodiment, the drive DC motor 30 is driven without driving the stepping motor 20 at the time of the retraction operation and zooming, and the stepping motor 20 is driven without driving the DC motor 30 at the transition from the tele state to the macro state. To drive. However, the DC motor 30 and the stepping motor 20 may be simultaneously driven to move the second and third lens units L12 and L13.

  Further, in the present embodiment, one stepping motor 20 is used to move the second and third lens units L12 and L13 in the cam cylinder 21. Therefore, the cam cylinder and the lens barrel can be miniaturized as compared with the case where the second and third lens units L12 and L13 are respectively moved using two stepping motors, whereby the camera can be miniaturized. It is.

  Next, a lens barrel which is Embodiment 2 of the present invention will be described. The lens barrel of this embodiment is also used for a compact digital camera as in the first embodiment. FIG. 9, FIG. 10, FIG. 11 and FIG. 12 show the internal configuration of the lens barrel of this embodiment in the retracted state, wide state, tele state and macro state, respectively. FIG. 13 and FIG. 14 respectively show the lens barrel of the present embodiment as viewed obliquely and disassembled.

  The lens barrel includes an imaging optical system including a first group lens L21 as a plurality of lens units, a second group lens (first lens unit) L22, a third group lens (second lens unit) L23, and a fourth group lens L24. Have. Reference numeral 31 denotes a first group cylinder that holds a first group lens L21. One set of six cam pins 31 a disposed at the rear end of the inner peripheral surface of the first group cylinder 31 is engaged with the cam groove portion 41 a formed on the outer peripheral surface of the cam cylinder 41. Straight keys 31 b are formed at three positions on the rear end of the outer peripheral surface of the first group cylinder 31. The rectilinear key 31 b is engaged with a rectilinear groove 46 c formed on the inner peripheral surface of the fixed cylinder 46.

  Reference numeral 32 denotes a second group cylinder that holds a second group lens L22. The cam pin 32 a disposed on the outer peripheral surface of the second group cylinder 32 is engaged with the cam groove portion 42 a formed on the outer peripheral surface of the second group cylindrical cam (first cam member) 42. Positioning groove portions 32 b and 32 c are formed in the second group cylinder 32. Guide shafts 36a and 36b formed on the motor holding frame 36 are engaged with the positioning groove portions 32b and 32c.

  Reference numeral 33 denotes a third group holding frame for holding the third group lens L23. The cam pin 33 a disposed on the outer peripheral surface of the third group holding frame 33 is engaged with the cam groove portion 43 a formed on the inner peripheral surface of the third group cylindrical cam (second cam member) 43. Positioning groove portions 33 b and 33 c are formed in the third group holding frame 33. Guide shafts 36a and 36b formed on the motor holding frame 36 are engaged with the positioning groove portions 33b and 33c.

  The motor holding frame 36 holds a stepping motor (second actuator) 40. Three projections 36 c formed at the front end of the motor holding frame 36 are engaged with grooves 41 d formed in the inner peripheral surface of the cam cylinder 41. The motor holding frame 36 is rotatably supported by the cam cylinder 41 around the optical axis, and moves in the optical axis direction integrally with the cam cylinder 41. The stepping motor 40 has a drive shaft 40 a that extends parallel to the optical axis of the imaging optical system.

  As shown in FIG. 15, on the drive shaft 40a of the stepping motor 40, a second group cylindrical cam 42 and a third group cylindrical cam 43 are attached at an interval D2 slidably in the axial direction of the drive shaft 40a. . The second group cylindrical cam 42 and the third group cylindrical cam 43 rotate integrally with the drive shaft 40 a of the stepping motor 40. That is, the second group cylindrical cam 42 and the third group cylindrical cam 43 rotate around an axis parallel to the optical axis. Further, on the drive shaft 40a, the second group and third group cylindrical cams 42, 43 are brought close to each other via washers 40b, 40c respectively abutting on one end of the second group and third group cylindrical cams 42, 43 (the interval D2 is short Springs 40d and 40e are provided so as to be biased. With this configuration, cam portions (third and fourth cam portions) 41b, the other ends of the second and third group cylindrical cams 42 and 43 are formed on the inner peripheral surface of the cam cylinder (third cam member) 41, It is pressed against 41c.

  The second group cylindrical cam 42, the third group cylindrical cam 43, and the stepping motor 40 described above are disposed radially inward of the cam cylinder 41.

  Reference numerals 34 and 35 denote an aperture unit and a shutter ND unit, respectively. The aperture unit 34 and the shutter ND unit 35 are fixed to the third group holding frame 33 by screws (not shown).

  One set of three cam pins 41 e disposed at the rear end of the outer peripheral surface of the cam cylinder 41 is engaged with the cam groove portion 46 a formed in the inner peripheral surface of the fixed cylinder 46. A set of three drive pins 41 f arranged at the rear end of the outer peripheral surface of the cam cylinder 41 penetrates the through groove 46 b formed in the fixed cylinder 46 and is a rectilinear groove 47 a formed in the inner peripheral surface of the drive cylinder 47. Is engaged.

  The fixed barrel 46 linearly guides the first barrel 31 in the optical axis direction, and the motor holding frame 36 linearly guides the second barrel 32 and the third barrel 33. Further, the three rectilinear keys 36 d formed on the outer peripheral surface of the motor holding frame 36 are engaged with the rectilinear groove portions 46 c formed on the inner peripheral surface of the fixed cylinder 46.

  A gear portion 47 b formed at the rear end of the outer peripheral surface of the drive cylinder 47 is connected to a drive cylinder drive unit constituted by a DC motor (first actuator) 50 and a plurality of gears 49. The drive cylinder 47 is rotated by the output of the drive cylinder drive unit. Thus, the cam barrel 41 has a cam action between the cam pin 41e and the cam groove portion 46a of the fixed barrel 46 and a rectilinear guide action between the drive pin 41f of the cam barrel 41 and the rectilinear groove portion 47a of the drive barrel 47. It moves in the optical axis direction while rotating around the optical axis.

  The first group cylinder 31 has a cam action between the cam pin 31a of the first group cylinder 31 and the cam groove 41a of the cam cylinder 41, and the straight movement key between the straight movement key 31b of the first group cylinder 31 and the straight movement key 46c of the fixed cylinder 46. It moves in the optical axis direction without rotating around the optical axis by the guide action.

  The second group cylindrical cam 42 follows the movement of the cam portion 41b of the cam cylinder 41 in the optical axis direction, and moves on the drive shaft 40a of the stepping motor 40 in the axial direction, that is, the optical axis direction. The third group cylindrical cam 43 also moves on the drive shaft 40 a of the stepping motor 40 in the optical axis direction following the movement of the cam portion 41 c of the cam cylinder 41 in the optical axis direction.

  The second group cylinder 32 moves in the optical axis direction together with the cam portion 41 b of the cam cylinder 41 unless the second group cylindrical cam 42 is rotated. When the second group cylindrical cam 42 rotates, the cam action between the cam pin 32a of the second group cylinder 32 and the cam groove portion 42a of the second group cylindrical cam 42 and the positioning holes 32b and 32c of the second group cylinder 32 and the guide of the motor holding frame 36 It moves in the direction of the optical axis without rotating around the optical axis due to the rectilinear guide action between the shafts 36a and 36b.

  The third group holding frame 33 also moves in the optical axis direction together with the cam portion 41 c of the cam cylinder 41 unless the third group cylindrical cam 43 is rotated. When the third group cylindrical cam 43 rotates, the cam action between the cam pin 33a of the third group holding frame 33 and the cam groove portion 43a of the third group cylindrical cam 43 and the positioning holes 33b and 33c of the third group holding frame 33 and the motor holding frame 36 Due to the rectilinear guide action between the guide shafts 36a and 36b, they move in the optical axis direction without rotating.

  The imaging element S2 and the optical filter F2 are held by the fixed ground plane 48. The imaging element S2 is a photoelectric conversion element such as a CCD sensor or a CMOS sensor. The optical filter F2 has an infrared cut function and the like.

  Next, the operation of the lens barrel configured as described above will be described. The operation of the lens barrel is controlled by a camera microcomputer 70 as control means shown in FIG.

  A drive signal is input from the camera microcomputer 70 to the DC motor 50 in order to make the lens barrel from the retracted state shown in FIG. 9 through the wide state shown in FIG. 10 to the tele state shown in FIG. When the DC motor 50 is driven according to this, the rotational output is transmitted to the gear portion 47 b of the drive cylinder 47 via the plurality of gears 49. As a result, the drive cylinder 47 rotates around the optical axis with respect to the fixed cylinder 46, and the cam cylinder 41 moves from the collapsed position to the position in the wide state where it protrudes forward of the fixed cylinder 46, and further to the position in the tele state. Do.

  At this time, the camera microcomputer 70 supplies the stepping motor 40 with a holding signal for holding the stepping motor 40 in the stopped state (that is, energization for stopping and holding is performed). As a result, since the second group cylindrical cam 42 is not rotated, the second group cylinder 32 moves in the optical axis direction following the cam portion 41 b of the cam cylinder 41. Further, since the third group cylindrical cam 43 is not rotated, the third group holding frame 33 moves in the optical axis direction following the cam portion 41 c of the cam cylinder 41.

  Furthermore, at the same time, the camera microcomputer 70 does not rotate integrally with the cam cylinder 41 by the frictional force generated on the contact surfaces of the second and third group cylindrical cams 42 and 43 with the cam portions 41 b and 41 c of the cam cylinder 41. Control the stepping motor 40. That is, as in the first embodiment (FIG. 7), when the camera microcomputer 70 detects the rotation of the second and third cylindrical cams 42 and 43 by the detection means constituted by the pulse plate and the photo interrupter, The stepping motor 40 is controlled in the return direction. Thereby, the rotation of the second and third group cylindrical cams 42 and 43 is suppressed.

  To set the tele state shown in FIG. 11 to the macro state shown in FIG. 12, the stepping motor 40 is driven without driving the DC motor 50, that is, without rotating the cam cylinder 41, and the second group cylindrical cam 42 And the third group cylindrical cam 43 are rotated. Thereby, the second group cylinder 32 and the third group holding frame 33, that is, the second group lens L22 and the third group lens L23 are moved to the position in the macro state.

  In FIG. 16, the cam groove portions 42a and 43a of the second group cylindrical cam 42 and the third group cylindrical cam 43 are expanded in the circumferential direction and shown. The upper side of the figure is the subject side. 16, positions of cam pins 32a and 33a indicated by 3P1 and 4P1 correspond to the tele state shown in FIG. 11, and positions of cam pins 32a and 33a indicated to 3P3 and 4P3 correspond to the macro state shown in FIG. Further, in this embodiment, an intermediate macro state can be selected as a macro state different in magnification from the macro state shown in FIG. 12. In this case, the cam pins 32a and 33a are located at the positions shown in 3P2 and 4P2. .

  In the present embodiment, during the retraction operation and zooming, without rotating the second and third group cylindrical cams 42 and 43 in the optical axis direction between the second and third group cylindrical cams 42 and 43 via the DC motor 50. Change the interval D2. Thereby, the second and third lens units L22 and L23 are moved.

  On the other hand, at the time of transition from the tele state to the macro state, without driving the DC motor 50, the second and third cylindrical cams 42 and 43 are rotated via the stepping motor 40 to rotate the second and third lens groups L22 and L23. Move At this time, the second and third cylindrical cams 42 and 43 are integrally rotated. With this configuration, the second and third lens groups L22 and L23 are rotated as a component in which the second cam cylinder 42 and the third cam cylinder 43 are integrally formed (that is, a component without the distance D2 in the optical axis direction). As compared with the case of driving, it is possible to improve the freedom of the moving amount of the second and third lens units L12 and L13. The second and third lens groups L22 and L23 are the combined lift amount of the lift amount of the cam groove 41b, 41c of the cam cylinder 41 and the lift amount of the cam groove 42a, 43a of the second and third group cylindrical cams 42, 43. Move in the optical axis direction.

  In the present embodiment, the driving DC motor 50 is driven without driving the stepping motor 40 at the time of the retraction operation and zooming, and the stepping motor 40 is not driven at the transition from the tele state to the macro state. To drive. However, the DC motor 50 and the stepping motor 4 may be simultaneously driven to move the second and third lens units L22 and L23.

  In the present embodiment, one stepping motor 40 is used to move the second and third lens units L22 and L23 in the cam cylinder 41. For this reason, the cam cylinder and the lens barrel can be miniaturized as compared with the case where the second and third lens groups L22 and L23 are respectively moved using two stepping motors, whereby the camera can be miniaturized. It is.

  Furthermore, in the present embodiment, the second group cylindrical cam 42 and the third group cylindrical cam 43 are mounted on the drive shaft (output shaft) 40a of the stepping motor 40, and these are configured as one cam drive unit, Assembling workability of the lens barrel can be improved.

  FIG. 17 shows a camera 300 configured of the lens barrel 100 described in the first or second embodiment and a camera body 200 provided with the lens barrel 100. The camera body 200 accommodates the lens barrel 100 and holds the fixed ground plate 28 or 48 holding the imaging element S1 or S2.

  By using the lens barrel 100 described in the first or second embodiment, it is possible to realize the camera 300 which is compact but can perform zooming, macro imaging, and a collapsing operation of the lens barrel 100.

  Although the first and second embodiments described the case where the first group cylinder and the cam cylinder have a two-stage telescopic collapsible lens barrel which advances and retracts, as another embodiment, one movable cylinder is opposed to the imaging device main body. It may be a one-stage telescopic type collapsible lens barrel which moves back and forth. In addition, it may be a telescopic lens barrel of three or more stages in which three or more movable cylinders move relative to each other and move relative to the imaging apparatus main body. Furthermore, the lens barrel may perform zooming and transition to the macro state without performing the retraction operation.

In the first and second embodiments, the lens barrel used in the digital compact camera has been described. However, as another embodiment, the lens barrel of another imaging apparatus such as a video camera or a film camera may be used.
(Other embodiments)
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

  The embodiments described above are only representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

L12, L22 Second group lens L13, L23 Third group lens 20, 40 Stepper motor 21, 41 Cam cylinder 22 Second group cam cylinder 23 Third group cam cylinder 30, 50 DC motor 42 Second group cylindrical cam 43 Third group cylindrical cam

Claims (10)

A lens barrel capable of moving a plurality of lens units in the optical axis direction, wherein
A first cam portion is provided, and by rotating around the optical axis of the lens barrel or an axis parallel to the optical axis, the first of the plurality of lens units may be rotated via the first cam portion. A first cam member for moving the lens unit in the direction of the optical axis;
A second cam unit is provided, and by rotating around the optical axis, a second lens unit of the plurality of lens units is moved in the optical axis direction via the second cam unit. And cam members,
It has a third cam portion and a fourth cam portion, and is rotated about the optical axis or about an axis parallel to the optical axis, thereby interposing the third cam portion and the fourth cam portion. A third cam member for moving the first cam member and the second cam member in the optical axis direction;
A first actuator for rotating the third cam member;
And a second actuator for rotating the first and second cam members.   The first actuator is driven to move the first and second lens units to perform zooming, and the second actuator is driven to move the first and second lens units to the zooming. The lens barrel according to claim 1, wherein the lens barrel is moved to a position different from the position.   The first actuator is driven to move the first and second lens units to perform zooming and storage operations, and the second actuator is driven to move the first and second lens units. The lens barrel according to claim 1, wherein the lens barrel is moved to a position different from the position at the time of zooming and the position after the storing operation.   The lens barrel according to claim 2, wherein the different position is a position for macro photographing.   The said 1st cam member, the said 2nd cam member, and the said 2nd actuator are arrange | positioned inside the radial direction of the said 3rd cam member, The any one of the Claims 1 to 4 characterized by the above-mentioned. The lens barrel described in the item.   The third cam member is configured such that when the second actuator is energized for stopping and holding and the rotation of the first and second cam members about the optical axis is stopped, The lens barrel according to any one of claims 1 to 5, wherein the first and second cam members are moved in the optical axis direction by being rotated by the actuator (1). Detection means for detecting rotation of the first and second cam members;
And controlling means for controlling the second actuator so as to suppress the rotation in response to the detection of the rotation by the detection means when driving the first actuator. The lens barrel according to claim 6.   The lens barrel according to any one of claims 1 to 7, wherein the first and second cam members are both formed as cylindrical cams.   The lens barrel according to any one of claims 1 to 8, wherein the first and second cam members are configured as one drive unit together with the second actuator. The lens barrel according to any one of claims 1 to 9,
An imaging apparatus comprising: a camera body provided with the lens barrel.