JP6633490B2 - Lens drive mechanism, and lens unit and camera having the same - Google Patents

Description

  The present invention relates to a lens driving mechanism, and more particularly, to a lens driving mechanism capable of manual and automatic focusing, a lens unit including the same, and a camera.

  For lens units and cameras that can perform both automatic focus adjustment and manual focus adjustment, switch between the automatic focus mode and manual focus mode by operating a switch or focus ring, switch the mode, and then manually adjust the focus with the focus ring Or press the release button halfway to start automatic focus adjustment.

  On the other hand, Japanese Patent Application Laid-Open No. 10-153731 (Patent Document 1) describes a lens barrel. With this lens barrel, automatic and manual focus adjustment can be performed without switching between the automatic focus mode and the manual focus mode. This lens barrel is provided with a planetary gear mechanism, rotation by a drive motor for automatic focusing is input to an input gear of the planetary gear mechanism, rotation by manual focus adjustment is input to a crown gear of the planetary gear mechanism, The output gear of the planetary gear mechanism is connected to the drive ring of the focus lens.

  When the planetary gear mechanism is used in this manner, when the input gear is rotated by the drive motor while the crown gear to which the rotation for manual focus adjustment is input is stopped, the output gear is rotated based on this rotation, and the focus lens is rotated. Is moved. On the other hand, while the input gear is stopped, the crown gear is rotated by operating the focus ring, the output gear is rotated based on this rotation, and the focus lens is moved. By configuring the focus adjustment mechanism in this way, the focus can be adjusted manually by operating the focus ring without performing the mode switching operation, and automatically adjusted by pressing the release button halfway. , And so-called full-time manual focus adjustment can be realized.

JP-A-10-153731

  However, in the lens barrel described in Japanese Patent Application Laid-Open No. H10-153731, when performing manual focusing, it is necessary to stop the input gear rotated during automatic focusing. However, when a motor having a small self-holding force, such as a stepping motor or a brushless DC motor, is used as a driving motor for automatic focusing, the input gear moves during manual focusing adjustment, and the operating force due to manual focusing is increased. However, there is a problem that is not sufficiently transmitted to the output gear. Therefore, in the mechanism described in Japanese Patent Application Laid-Open No. 10-153731, the drive motor used for automatic focusing is limited to a motor having a large self-holding force, such as an ultrasonic motor.

  In order to avoid this problem, a drive motor for automatic focusing and some kind of brake mechanism are added to the transmission path of the rotation of the drive motor to prevent the input gear from moving during manual focus adjustment. May be given. However, if a drive motor or a brake mechanism is provided in its transmission path, there is a problem that smooth focus adjustment cannot be performed during automatic focusing. That is, when the brake is applied to the rotation of the drive motor, it becomes difficult to freely control the drive motor at low speed during automatic focus adjustment, and the focus lens cannot be moved smoothly at low speed. Such a problem is particularly remarkable in moving image shooting in which the focus position needs to be smoothly moved at a low speed. In this case, the merit of adopting a stepping motor or a brushless DC motor that can smoothly rotate at a low speed for focus adjustment cannot be fully utilized.

  Accordingly, the present invention provides a full-time manual lens driving mechanism capable of performing smooth focus adjustment even when a motor having a small self-holding force is used, and a lens unit and a camera including the same. It is intended to be.

In order to solve the above-described problem, the present invention is a lens driving mechanism for driving a focus lens for performing focusing, and transmits a driving force based on a user operation for manually driving the focus lens. A first driving force transmitting unit, a second driving force transmitting unit for transmitting a driving force of a driving motor for automatically driving the focus lens, and a first driving force transmitting unit or a second driving force transmitting unit. An output unit for outputting a driving force for moving the focus lens in the optical axis direction based on the driving force, and a second driving force transmission when the driving force is transmitted from the first driving force transmission unit to the output unit. a brake mechanism for stopping the transmission of the driving force by the parts, by the brake mechanism, and stopping transmission of the driving force by the second driving force transmission unit and a brake switching mechanism for switching between release stopping, the user operation And a detecting unit for detecting the transmission of the driving force to the first driving force transmitting unit. The brake switching mechanism detects when the detecting unit detects the transmission of the driving force to the first driving force transmitting unit. The braking mechanism is switched so that a braking force is applied to the output shaft of the driving motor .

  In the present invention thus configured, the first driving force transmission unit transmits a driving force based on a user operation for manually driving the focus lens. The second driving force transmission unit transmits a driving force based on power from a power source for automatically driving the focus lens. The output unit outputs a driving force for moving the focus lens in the optical axis direction based on the driving force transmitted from the first driving force transmitting unit or the second driving force transmitting unit. The brake mechanism stops the transmission of the driving force by the second driving force transmission unit when the driving force is transmitted from the first driving force transmission unit to the output unit.

  According to the present invention thus configured, the brake mechanism stops the transmission of the driving force by the second driving force transmission unit when the driving force is transmitted from the first driving force transmission unit to the output unit. Therefore, the focus can be reliably operated.

  In the present invention, preferably, the brake mechanism keeps stopping the transmission of the driving force by the second driving force transmission unit while the driving force is transmitted to the output unit from the first driving force transmission unit.

In the present invention, preferably, the brake switching mechanism cancels the stop of the transmission of the driving force by the second driving force transmission unit while the detection unit does not detect the transmission of the driving force to the first driving force transmission unit.

In the present invention, preferably, the brake switching mechanism releases the stop of the transmission of the driving force by the second driving force transmission unit only while the power from the driving motor is transmitted to the second driving force transmission unit. While the brake mechanism is switched, the transmission of the driving force to the first driving force transmission unit is detected by the detection unit even while the power from the driving motor is being transmitted to the second driving force transmission unit. During this time, the brake mechanism is switched so as to stop the transmission of the driving force by the second driving force transmission unit.

  In the present invention, preferably, there is provided a driving force transmission unit for transmitting the driving force from the first driving force transmission unit and the second driving force transmission unit to the output unit.

In the present invention, preferably, the first driving force transmission unit is configured by a first gear that rotates according to a user operation, and the second driving force transmission unit rotates based on the driving force transmitted from the driving motor. The output unit is constituted by an output gear, and the driving force transmission unit is constituted by a planetary rotating member that transmits the rotation of the first gear and the second gear to the output gear.

  Further, the present invention is a lens unit capable of manual and automatic focusing, comprising a lens barrel, a lens disposed inside the lens barrel, and a lens driving mechanism of the present invention. It is characterized by.

  Further, the present invention is a camera capable of focusing manually and automatically, and includes a camera body and a lens unit of the present invention attached to the camera body.

  ADVANTAGE OF THE INVENTION According to the lens drive mechanism of this invention, the lens unit provided with the same, and a camera, even if it uses a motor with a small self-holding force, it can perform full-time manual type smooth focus adjustment.

FIG. 1 is a sectional view of a camera including a lens driving mechanism according to a first embodiment of the present invention. FIG. 2 is a perspective view of the lens driving mechanism according to the first embodiment of the present invention as viewed in an optical axis direction. FIG. 2 is a cross-sectional view of the lens driving mechanism according to the first embodiment of the present invention in an optical axis direction. FIG. 2 is an exploded perspective view showing a planetary gear mechanism built in the lens driving mechanism according to the first embodiment of the present invention. FIG. 2 is an enlarged sectional view showing a planetary gear mechanism incorporated in the lens driving mechanism according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of a brake mechanism provided in the lens drive mechanism according to the first embodiment of the present invention, showing a state where a braking force is applied. FIG. 3 is a cross-sectional view of a brake mechanism provided in the lens drive mechanism according to the first embodiment of the present invention, showing a state where no braking force is applied. FIG. 2 is an exploded perspective view of a brake mechanism provided in the lens drive mechanism according to the first embodiment of the present invention. FIG. 3 is a plan view of a coil assembly provided in a brake mechanism of the lens driving mechanism according to the first embodiment of the present invention. FIG. 3 is a plan view of a magnet plate provided in the brake mechanism of the lens drive mechanism according to the first embodiment of the present invention. 5 is a flowchart of control executed by a brake switching mechanism provided in the brake mechanism of the lens driving mechanism according to the first embodiment of the present invention. 4 is a time chart showing a voltage applied to a coil assembly of the brake mechanism by a brake switching mechanism provided in the brake mechanism of the lens drive mechanism according to the first embodiment of the present invention. FIG. 7 is an enlarged sectional view of a differential transmission mechanism employed in a lens drive mechanism according to a second embodiment of the present invention.

  Next, an embodiment of the present invention will be described with reference to the accompanying drawings. First, a camera provided with a lens driving mechanism according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a camera provided with a lens driving mechanism according to a first embodiment of the present invention.

  As shown in FIG. 1, the camera 1 has a lens unit 2 and a camera body 4. The lens unit 2 includes a lens barrel 6, a plurality of lenses 8 arranged in the lens barrel, and a lens driving mechanism 10 for moving the focus lens 16 in the direction of the optical axis A of the lens unit 2. .

  The lens unit 2 is attached to the camera body 4 and is configured to focus incident light on the imaging element surface 4a. The generally cylindrical lens barrel 6 holds a plurality of lenses 8 therein, and enables focus adjustment by moving a focus lens 16 by a lens driving mechanism 10.

  Further, around the lens barrel 6, a cylindrical focus operation unit which is operated for manually moving the focus lens 16 (that is, receives an operation for manually moving the focus lens 16) is a manual focus operation unit. The focus ring 12 is rotatably mounted, and when the photographer manually rotates the focus ring 12, the focus lens 16 is moved in the direction of the optical axis A via the lens driving mechanism 10 to manually adjust the focus. Is performed.

  On the other hand, the camera body 4 is provided with an automatic focus operation unit operated to start focusing by automatic focus for automatically moving the focus lens. Further, the camera body 4 has a built-in automatic focus control unit 14, and based on a signal from the automatic focus control unit 14, the lens driving mechanism 10 moves the focus lens 16 to perform automatic focusing. it can. That is, when the photographer half-presses the release button 4b, which is an auto-focus operation unit provided on the camera body 4, the auto-focusing is started, and the auto-focus control unit 14 sets the image of the subject to the image sensor surface. The position of the focus lens 16 is adjusted so as to focus on 4a. The lens drive mechanism 10 drives a built-in drive motor 18 (FIG. 2) based on a control signal from the automatic focus control unit 14 to move the focus lens 16 to a commanded position. Therefore, the camera 1 according to the present embodiment is capable of keeping the focus lens 16 illuminated both when the driving motor 18 is driven and when the focus ring 12 is rotated without performing the switching operation between the manual focus and the automatic focus. This is a so-called full-time manual camera that is moved in the direction of the axis A and performs focusing instantaneously and continuously.

  Next, a lens driving mechanism 10 according to a first embodiment of the present invention, which is built in the lens unit 2, will be described with reference to FIGS.

  FIG. 2 is a perspective view of the lens driving mechanism viewed in the optical axis direction. FIG. 3 is a cross-sectional view of the lens driving mechanism in the optical axis direction.

  As shown in FIGS. 2 and 3, the lens driving mechanism 10 includes a driving motor 18, a manual operation ring 20, a focus lens driving ring 22 which is a lens moving mechanism, a manual focus operation detection gear 24, It has a slip gear 26, a second slip gear 28, an idler gear 30, a worm wheel 32, a planetary gear mechanism 34, a worm 36, a brake mechanism 60, and a brake switching mechanism 62. Further, the lens driving mechanism 10 has a first housing 46 and a second housing 48 that support the rotating shaft of each gear and house each gear.

  The drive motor 18 is a DC motor that is driven based on a control signal from the automatic focus control unit 14, and is a motor that serves as a power source for driving the focus lens 16 during automatic focusing. During manual focusing, a braking force is applied to the motor output shaft 18a of the driving motor 18 by the brake mechanism 60, and resistance is given to the rotation of the motor output shaft 18a. The detailed configuration of the brake mechanism 60 will be described later.

  The manual operation ring 20 (FIG. 2) is a cylindrical member provided on the lens unit 2 so as to be rotatable around the optical axis A, and is configured to interlock with the focus ring 12 operated by the photographer. Have been. Gear teeth 20 a are provided on a part of the inner peripheral surface of the manual operation ring 20, and the gear teeth 20 a mesh with the first slip gear 26. Therefore, when the focus ring 12 is operated by the photographer, the first slip gear 26 is rotated via the manual operation ring 20.

  The focus lens drive ring 22 (FIG. 2) is a cylindrical member provided on the lens unit 2 so as to be rotatable about the optical axis A. A cam groove (not shown) is provided on the inner wall surface of the focus lens drive ring 22. When the focus lens drive ring 22 is rotated, the focus lens 16 moves in the direction of the optical axis A according to the cam groove. It is supposed to be. Therefore, the focus lens drive ring 22 functions as a lens moving mechanism. Further, gear teeth 22a are provided on a part of the inner peripheral surface of the focus lens drive ring 22, and the gear teeth 22a mesh with an output gear 44 (FIG. 3) of the planetary gear mechanism. The details of the planetary gear mechanism 34 will be described later.

  The manual focus operation detection gear 24 is a spur gear arranged to mesh with the first slip gear 26. When the first slip gear 26 is rotated based on the operation of the focus ring 12, the manual focus operation detection gear 24 rotates in conjunction therewith. Is done. An encoder wheel 24a is coaxially mounted on the manual focus operation detection gear 24, and rotates together. Further, a detection sensor 50 is disposed near the encoder wheel 24a, and optically detects the rotation of the encoder wheel 24a in a non-contact manner.

  Thus, when the photographer operates the focus ring 12, the first slip gear 26, the manual focus operation detecting gear 24, and the encoder wheel 24a are rotated, and the rotation is detected by the detection sensor 50. Can be detected. A detection signal from the detection sensor 50 is sent to a brake switching mechanism 62 (FIG. 3), and the brake switching mechanism 62 switches the application / release of the braking force by the brake mechanism 60 based on the input signal. In the present embodiment, the brake switching mechanism 62 is configured by a microprocessor, a memory, and a program (not shown) for operating these components. Control of the brake mechanism 60 by the brake switching mechanism 62 will be described later.

  The first slip gear 26 is a spur gear arranged to mesh with the gear teeth 20 a of the manual operation ring 20, and is configured to rotate in conjunction with the manual operation ring 20.

  The second slip gear 28 is a spur gear, and is attached to the same rotation shaft as the first slip gear 26. A slip spring 28a (FIG. 3) is arranged so as to surround the rotation shaft, and the second slip gear 28 is pressed against the side surface of the first slip gear 26 by the urging force of the slip spring 28a. Therefore, a predetermined frictional force acts between the first slip gear 26 and the second slip gear 28, and the second slip gear 28 is rotated in conjunction with the first slip gear 26 by the frictional force. However, when the torque transmitted between the first slip gear 26 and the second slip gear 28 becomes equal to or more than a predetermined value, the frictional force is overcome, and the slip gears slip between the two slip gears, so that the wheels slip. This prevents an excessive torque from acting on each gear due to the operation of the focus ring 12 by the photographer, thereby preventing the gears from being damaged.

  The idler gear 30 is a spur gear arranged to mesh with the second slip gear 28. Further, the idler gear 30 is arranged so as to mesh with an input gear 42 (FIG. 3) which is a first input portion of the planetary gear mechanism 34, and the torque transmitted to the second slip gear 28 is transmitted through the idler gear 30. And transmitted to the planetary gear mechanism 34. Further, a brake spring 30a (FIG. 3) is disposed so as to surround the rotation shaft of the idler gear 30, and the biasing force of the brake spring 30a presses the side surface of the idler gear 30 against the friction plate 30b. A predetermined rotational resistance is given to the rotation of the idler gear 30 by being pressed against the friction plate 30b. For this reason, when the focus ring 12 is operated by the photographer, torque is transmitted to the idler gear 30 via the first slip gear 26 and the second slip gear 28, and the idler gear 30 resists the applied rotational resistance. 30 is rotated, and this rotation is transmitted to the input gear 42 of the planetary gear mechanism 34. Therefore, the idler gear 30, the brake spring 30a, and the friction plate 30b function as a manual brake mechanism.

  The worm 36 is a gear attached to the motor output shaft 18 a of the driving motor 18, and is arranged so as to mesh with the worm wheel 32.

  The worm wheel 32 is a gear formed integrally with a sun gear 38 (FIG. 3), which is a second input portion of the planetary gear mechanism 34, and is arranged to be rotatable about a transmission rotation shaft 32a. The transmission rotation shaft 32a is oriented in a direction parallel to the optical axis A, and is substantially perpendicular to the motor output shaft 18a of the driving motor 18. The rotation of the motor output shaft 18a of the drive motor 18 is transmitted via the worm 36 and the worm wheel 32 to the transmission rotation shaft 32a orthogonal to the motor output shaft 18a. As described above, by using the worm 36 and the worm wheel 32 to arrange the motor output shaft 18a of the drive motor 18 and the transmission rotation shaft 32a orthogonally, the output shaft of the drive motor and the transmission rotation shaft are The dimension of the lens driving mechanism 10 in the direction of the optical axis A can be reduced as compared with the case where the lens driving mechanism is arranged in parallel.

  Next, a configuration of the planetary gear mechanism 34 built in the lens driving mechanism 10 will be described with reference to FIGS. FIG. 4 is an exploded perspective view showing a planetary gear mechanism built in the lens driving mechanism. FIG. 5 is an enlarged sectional view showing a planetary gear mechanism incorporated in the lens driving mechanism.

  As shown in FIG. 4, the planetary gear mechanism 34 includes a sun gear 38 as a sun rotating member, and three planetary gears 40 as planetary rotating members (power transmission units) arranged so as to be in contact with the sun gear 38. And an input gear 42 arranged to be in contact with these planetary gears 40, and an output gear 44 as a rotation output member. The output gear 44, which is an output unit of the planetary gear mechanism 34, is rotatably supported by an output gear support shaft 52, which is an output member support shaft. Further, the planetary gear mechanism 34 has a first radial bearing 54a that rotatably supports the transmission rotary shaft 32a at an end on the worm wheel 32 side, and rotatably supports the transmission rotary shaft 32a at an end on the output gear 44 side. And a third radial bearing 56 (FIG. 5) for rotatably supporting the output gear 44.

  The planetary gear mechanism 34 including these members is configured to output a difference between the rotation input from the input gear 42 as the first gear and the rotation input from the sun gear 38 as the second gear by the planetary gear 40. The corresponding rotation is output from the output gear 44, which is an output gear, and functions as a differential transmission mechanism. In the lens driving mechanism 10 of the present embodiment, at the time of manual focusing, the input gear 42 is rotated with the sun gear 38 stopped, and the rotation of the input gear 42 is transmitted to the output gear 44. Further, at the time of automatic focusing, the sun gear 38 is rotated with the input gear 42 stopped, and the rotation of the sun gear 38 is transmitted to the output gear 44.

  The sun gear 38 is a spur gear formed integrally with the worm wheel 32, and is rotated integrally with the worm wheel 32 about the transmission rotation shaft 32a. An end of the transmission rotating shaft 32a on the worm wheel 32 side is rotatably supported by a first radial bearing 54a embedded in the second housing 48. An end of the transmission rotating shaft 32a on the sun gear 38 side is It is rotatably supported by a second radial bearing 54b embedded in the output gear 44. The sun gear 38, the worm wheel 32, and the transmission rotation shaft 32a may be formed integrally with each other, or may be formed separately from each other and connected so as to be integrally rotated. You may.

  The planet gears 40 are three spur gears arranged around the sun gear 38 so as to mesh with the sun gear 38. Each of the planetary gears 40 is rotatably attached to three planetary gear shafts 44a, which are planetary support shafts formed so as to protrude from the end surface of the output gear 44. These three planetary gear shafts 44 a are provided at 120 ° intervals around the center axis of the output gear 44. Thus, when the sun gear 38 is rotated, each planetary gear 40 meshing with the sun gear 38 is rotated about the planetary gear shaft 44a.

  The input gear 42 is an annular spur gear disposed so as to surround the planetary gear 40, and is supported by the first housing 46 so as to be rotatable about the same axis as the sun gear 38 (FIG. 5). Inner peripheral teeth 42a are formed on the inner peripheral surface of the input gear 42 so as to mesh with the respective planetary gears 40, and outer peripheral teeth 42b are formed on the outer periphery so as to mesh with the idler gear 30 (FIG. 3). Thus, the rotation of the idler gear 30 is transmitted to each planetary gear 40 via the input gear 42.

  The output gear 44 is a substantially cylindrical member having three planetary gear shafts 44a formed on the end face on the sun gear 38 side and a spur gear formed on the opposite side. The planetary gear shafts 44a are formed at equal intervals on a circumference around the transmission rotation shaft 32a and in parallel with the transmission rotation shaft 32a so as to protrude from the end face of the output gear 44. Is rotatably supported. Further, a concave portion having a circular cross section is formed at the center of the end surface where the planetary gear shaft 44a is formed, and a second radial bearing 54b that supports one end of the transmission rotary shaft 32a is embedded in this concave portion. Therefore, the end of the transmission rotation shaft 32a on the sun gear 38 side is supported by the output gear 44.

  Output gear teeth 44b are provided on the outer peripheral surface of the output gear 44 on the side opposite to the planetary gear shaft 44a. The output gear teeth 44b mesh with the gear teeth 22a of the focus lens drive ring 22. Therefore, when the output gear 44 is rotated by the planetary gear mechanism 34, the focus lens drive ring 22 meshing with the output gear 44 is rotated, whereby the focus lens 16 is moved in the direction of the optical axis A. Further, a concave portion having a circular cross section (FIG. 5) is provided inside the output gear teeth 44b, and a third radial bearing 56 is disposed in the concave portion. The output gear support shaft 52 is inserted into the third radial bearing 56, and supports the output gear 44 so as to be rotatable about the output gear support shaft 52.

  Next, a support structure of the transmission rotary shaft 32a will be described with reference to FIG. As shown in FIG. 5, both ends of the transmission rotary shaft 32a are supported by a first radial bearing 54a and a second radial bearing 54b, respectively. As described above, the first radial bearing 54a that supports the worm wheel 32 side of the transmission rotation shaft 32a is embedded in the concave portion having a circular cross section provided in the second housing 48. On the other hand, the second radial bearing 54b that supports the sun gear 38 side of the transmission rotating shaft 32a is embedded in a concave portion having a circular cross section provided in the output gear 44. In the present embodiment, these first and second radial bearings are oilless type sliding bearings that can be used without lubrication. Similarly, the third radial bearing 56 embedded in the output gear 44 and receiving the output gear support shaft 52 also uses an oilless type slide bearing.

  The transmission rotation shaft 32a and the output gear support shaft 52 that support the worm wheel 32, the sun gear 38, and the output gear 44, respectively, are arranged on the same axis. The input gear 42 rotatably supported by the first housing 46 is also rotated about the same axis as the transmission rotation shaft 32a and the output gear support shaft 52. Therefore, the worm wheel 32, the sun gear 38, the input gear 42, and the output gear 44 are arranged so as to be rotatable about the same axis. On the other hand, the motor output shaft 18a of the drive motor 18 to which the worm 36 is attached is directed in a direction substantially orthogonal to the transmission rotation shaft 32a.

  Further, since torque is transmitted to the worm wheel 32 via the worm 36, a thrust direction force acts on the worm wheel 32 together with the rotational force. The thrust force acting on the worm wheel 32 is supported by both ends of the transmission rotation shaft 32a to which the worm wheel 32 is fixed, and the movement of the transmission rotation shaft 32a in the axial direction is restricted. That is, the end surface of the transmission rotary shaft 32a on the worm wheel 32 side contacts the bottom surface 48a of the concave portion of the second housing 48 that receives the first radial bearing 54a, and the axial movement of the transmission rotary shaft 32a is restricted. . On the other hand, the end face of the transmission rotary shaft 32a on the sun gear 38 side is in contact with the bottom surface 44c of the concave portion of the output gear 44 that receives the second radial bearing 54b, and the axial movement of the transmission rotary shaft 32a is restricted. Therefore, the bottom surface 48a and the bottom surface 44c of the concave portions provided in the second housing 48 and the output gear 44 respectively function as thrust support portions. In the present embodiment, the bottom surface 48a and the bottom surface 44c of each concave portion are each configured as a plane.

  Further, the axial force acting on the output gear 44 is supported by the distal end surface of the output gear support shaft 52 abutting against the bottom surface 44 d of the concave portion of the output gear 44 that receives the third radial bearing 56. Accordingly, the axial movement of the transmission rotating shaft 32 a in the downward direction in FIG. 5 is regulated by the output gear support shaft 52 via the output gear 44. In the present embodiment, the bottom surface 44d of the concave portion of the output gear 44 is configured to be flat.

  Here, both end surfaces of the transmission rotation shaft 32a are formed in a spherical shape. Therefore, each end face of the transmission rotation shaft 32a substantially makes point contact with the bottom surface 48a and the bottom surface 44c on the center axis of the transmission rotation shaft 32a. Similarly, the distal end surface of the output gear support shaft 52 is also formed in a spherical shape, and the distal end surface of the output gear support shaft 52 substantially makes point contact with the bottom surface 44d on the center axis of the output gear support shaft 52. . As described above, since each end face of the transmission rotation shaft 32a substantially makes point contact with the bottom surface 48a and the bottom surface 44c on the center axis of the transmission rotation shaft 32a, each end surface of the transmission rotation shaft 32a and the bottom surface 48a and the bottom surface 44c The friction torque generated between the two becomes very small. Similarly, the front end surface of the output gear support shaft 52 is substantially in point contact with the bottom surface 44d on the center axis of the output gear support shaft 52, so that the end surface between the front end surface of the output gear support shaft 52 and the bottom surface 44d is generated. The resulting friction torque is very small.

  In this manner, by forming both end surfaces of the transmission rotation shaft 32a and the end surface of the output gear support shaft 52 in a spherical shape, the drive motor 18 generates the thrust force based on the thrust force generated when the worm wheel 32 is driven. Therefore, it is possible to suppress the friction torque of the focus lens 16 and efficiently drive the focus lens 16. In order to cope with slight expansion due to thermal expansion of the transmission rotary shaft 32a, both end surfaces of the transmission rotary shaft 32a are not in contact with the bottom surface 48a and the bottom surface 44c at the same time, and there is a slight gap.

  Next, the configuration of the brake mechanism 60 will be described in detail with reference to FIGS. FIG. 6 is a cross-sectional view of the brake mechanism 60, showing a state in which a braking force is applied. FIG. 7 is a cross-sectional view of the brake mechanism 60, showing a state where no braking force is applied. FIG. 8 is an exploded perspective view of the brake mechanism 60. FIG. 9 is a plan view of a coil assembly provided in the brake mechanism 60. FIG. 10 is a plan view of a magnet plate provided in the brake mechanism 60. FIG.

  As shown in FIGS. 6 to 8, the brake mechanism 60 includes a movable disk 64, a guide shaft 66, a biasing coil spring 68, a core assembly 70, a coil assembly 72, and an attraction magnet 74. Have.

  As shown in FIG. 6, the movable disk 64 is a member including a disk-shaped disk portion 64a and a cylindrical portion 64b extending rearward from the center of the disk portion 64a. By inserting the guide shaft 66 into the cylindrical portion 64b of the movable disk 64, the movable disk 64 is slidably disposed along the guide shaft 66. On the front side of the cylindrical portion 64b, a friction disk 18b attached to the motor output shaft 18a of the drive motor 18 is disposed to face. When a braking force is applied by the brake mechanism 60, the disk portion 64a is pressed against the friction disk 18b of the driving motor 18 by the urging force of the urging coil spring 68, as shown in FIG. The rotation of the shaft 18a is prevented. On the other hand, when the braking force by the brake mechanism 60 is released, as shown in FIG. 7, the disk portion 64a is separated from the friction disk 18b against the urging force of the urging coil spring 68, and the motor output is reduced. The rotation of the shaft 18a becomes possible.

  The guide shaft 66 is a round bar made of metal, and a part of a side surface is cut out in a planar shape. The cylindrical portion 64b of the movable disk 64 that receives the guide shaft 66 is formed in a cross-sectional shape that matches the guide shaft 66, thereby preventing the movable disk 64 from rotating with respect to the guide shaft 66. A shaft boss 66 a is attached to the base end of the guide shaft 66, whereby the guide shaft 66 is connected to the core assembly 70.

  The biasing coil spring 68 is disposed so as to surround the guide shaft 66 and the cylindrical portion 64b of the movable disk 64, and the back side of the disk portion 64a of the movable disk 64 is attached to the friction disk 18b of the drive motor 18. It is urging towards. By the urging force of the urging coil spring 68, the front side of the disk portion 64a is pressed against the friction disk 18b of the drive motor 18, and a braking force is applied.

  The core assembly 70 is a member composed of a donut plate-shaped base 70a and six rod-shaped cores 70b having a rectangular cross section extending at right angles to the base 70a. The six core portions 70b are formed and arranged in parallel with the guide shaft 66 so as to surround the guide shaft 66 at equal intervals. When the braking force by the brake mechanism 60 is released, as shown in FIG. 7, the movable disk 64 is attracted to the tip of each core portion 70b and is separated from the friction disk 18b of the drive motor 18. Therefore, in the non-energized state, the movable disk 64 is pressed against the friction disk 18b of the drive motor 18 by the urging force of the urging coil spring 68, and a braking force is applied.

  The coil assembly 72 includes a flexible substrate 72a that guides current to each coil, and six cylindrical coils 72b that are vertically attached to the flexible substrate 72a. The respective core portions 70b of the core assembly 70 are inserted inside the respective cylindrical coils 72b, and the tips of the respective core portions 70b slightly protrude from the respective cylindrical coils 72b. With this configuration, when a current flows through each cylindrical coil 72b, each core 70b is magnetized, and the movable disk 64 can be attracted.

  As shown in FIG. 9, the six cylindrical coils 72b of the coil assembly 72 include two groups of three cylindrical coils in which current flows clockwise and three cylindrical coils in which current flows counterclockwise. And the cylindrical coils of each group are alternately arranged on the circumference. Further, two sets of circuit patterns 72c and 72d for supplying a current to each cylindrical coil 72b are formed on the flexible substrate 72a, and a current in a predetermined direction is supplied to each group of the cylindrical coils by these circuit patterns. Is done. In this embodiment, the tip of each core portion 70b of the core assembly 70 is magnetized by this current so that the S pole and the N pole are alternately arranged in the circumferential direction.

  As shown in FIG. 10, the attraction magnet 74 is a donut plate-shaped magnet made of ferrite rubber. The attracting magnet 74 has six fan-shaped magnetic poles surrounding the central opening. These magnetic poles are disposed so as to face the six core portions 70b of the coil assembly 72, respectively, and the S pole and the N pole have opposite polarities to the magnetic poles of the core portions 70b facing each other. They are formed so as to be alternately arranged in the circumferential direction.

  Further, a generally donut-shaped yoke 74a is arranged on the surface of the attraction magnet 74 on the side opposite to each core portion 70b (FIG. 8). The yoke 74a enhances the attraction force of the attraction magnet 74 when the tip of each core portion 70b is magnetized.

  On the other hand, a generally donut-shaped spacer 74b is disposed on the surface of the attraction magnet 74 on the side facing each core 70b (FIG. 8). The spacers 74b adjust the attraction force when the attraction magnets 74 are attracted to the respective core portions 70b, and also prevent the attraction magnets 74 from being damaged when attracted. The yoke 74a, the attracting magnet 74, and the spacer 74b are stacked in this order, receive the cylindrical portion 64b of the movable disk 64 in the opening at the center, and are attached to the back side of the disk portion 64a (FIG. 6). .

  Next, the operation of the lens driving mechanism 10 according to the first embodiment of the present invention will be described with reference to FIGS.

  First, when the photographer rotates the focus ring 12 (FIG. 1) to perform manual focusing, the manual operation ring 20 (FIG. 2) is rotated in conjunction with the rotation. When the manual operation ring 20 is rotated, the first slip gear 26 (FIG. 3) meshing with the gear teeth 20a is rotated, and accordingly, the manual focus operation detection gear 24 is rotated. When the manual focus operation detection gear 24 is rotated, the encoder wheel 24a attached thereto is rotated, and the rotation is detected by the detection sensor 50. A detection signal from the detection sensor 50 is input to a brake switching mechanism 62 (FIG. 3), and the brake switching mechanism 62 performs a braking mechanism based on the detection signal from the detection sensor 50 and a signal from the automatic focus control unit 14 (FIG. 1). 60 is controlled.

  On the other hand, when the first slip gear 26 (FIG. 3) is rotated, the second slip gear 28 is rotated accordingly, overcoming the braking force acting on the idler gear 30, and the rotation of the second slip gear 28 is reduced. The power is transmitted to the idler gear 30. When the idler gear 30 is rotated, the rotation is transmitted to the planetary gear mechanism 34. That is, the input gear 42 provided with the outer peripheral teeth 42b meshing with the idler gear 30 is rotated. Here, in a state in which the braking force is applied by the brake mechanism 60, the driving motor 18 is stopped, and the sun gear 38 that is linked with the driving motor 18 is also stopped. Since the input gear 42 is rotated with the sun gear 38 stopped in this way, the rotation of the input gear 42 is transmitted to the output gear 44 via each planetary gear 40, and when the input gear 42 is rotated, The output gear 44 is rotated at a predetermined rotation ratio. When the output gear 44 is rotated, the focus lens drive ring 22 provided with the gear teeth 22a (FIG. 2) meshing with the output gear teeth 44b is rotated, and the focus lens 16 (FIG. 1) is moved to the optical axis A. Moved in the direction.

  That is, the driving force by the user's focus ring operation, which is the driving force based on the user operation, is the driving force transmitted from the first slip gear 26 to the input gear 42 (first driving force transmission unit). When the detection sensor 50 (detection unit) detects that the focus rig 12 has been operated, the first driving force transmission unit outputs a driving force for moving the focus lens 16 in the optical axis direction to the output unit. When the transmission of the driving force is detected, the brake switching device 62 drives the brake mechanism 60 to apply the brake. As described above, when the focus ring 12 is operated by the user, the brake mechanism 60 applies the brake.

  Next, when the user half-presses the release button 4b (FIG. 1) of the camera body 4, the automatic focus control unit 14 causes the drive motor 18 (so that the image of the subject is focused on the imaging element surface 4a to be focused). FIG. 3) is driven. When the drive motor 18 is driven, the worm 36 attached to the motor output shaft 18a is rotated, and the worm wheel 32 meshing with the worm 36 is driven to rotate. That is, the power from the power source (the rotation of the driving motor 18) is transmitted to the worm wheel 32 which is the second driving force transmitting unit. The thrust force is generated in the axial direction of the transmission rotation shaft 32a by the rotation drive of the worm wheel 32, but the axial movement of the transmission rotation shaft 32a is restricted by the bottom surface 48a or the bottom surface 44c (FIG. 5) which is a thrust support. Is done. The thrust force is generated in any direction depending on the rotation direction of the worm wheel 32, and the thrust force is supported by the bottom surface 48a or the bottom surface 44c.

  When the worm wheel 32 is driven to rotate, the sun gear 38 formed integrally therewith is also driven to rotate. On the other hand, since a braking force is applied to the idler gear 30 by the urging force of the brake spring 30a (FIG. 3), the rotation of the input gear 42 meshing with the braking force is stopped. As described above, since the sun gear 38 is rotationally driven while the input gear 42 is stopped, the rotation of the sun gear 38 is transmitted to the output gear 44 at a predetermined rotation ratio via the planetary gear 40. . When the output gear 44 is rotated, the focus lens drive ring 22 provided with the gear teeth 22a (FIG. 2) meshing with the output gear teeth 44b is rotated, and the focus lens 16 (FIG. 1) is moved to the optical axis A. Direction, and automatic focus is executed.

  Next, control of the brake mechanism by the brake switching mechanism will be described with reference to FIGS. 11 and 12. FIG. 11 is a flowchart of the control executed by the brake switching mechanism. FIG. 12 is a time chart showing the voltage applied to the coil assembly of the brake mechanism by the brake switching mechanism.

  First, the brake mechanism 60 always applies a braking force by the urging force of the urging coil spring 68, and the braking force is released only when a voltage is applied to the coil assembly 72 by the brake switching mechanism 62. . Therefore, even when the power switch (not shown) of the camera 1 or the lens unit 2 is turned off, the braking force by the brake mechanism 60 is applied. Therefore, the motor output shaft 18a of the drive motor 18 is stopped even when no power is supplied, so that the user can move the focus lens 16 by operating the focus ring 12.

  The flowchart shown in FIG. 11 shows the processing by the brake switching mechanism 62. When the photographer half-presses the release button 4b (FIG. 1) to start focusing by automatic focusing, a signal from the automatic focusing control unit 14 is input to the brake switching mechanism 62, and the processing of the flowchart shown in FIG. Is started. At the time when the processing of the flowchart shown in FIG. 11 is started, the brake mechanism 60 is in a state of applying a braking force.

  First, in step S1 of FIG. 11, it is determined whether or not the photographer has operated the focus ring 12. That is, it is determined whether or not the detection sensor 50 (FIG. 3) detects the rotation of the encoder wheel 24a. If the rotation has not been detected, the process proceeds to step S2. If the rotation has been detected, the process proceeds to step S2. One process of the flowchart shown in FIG. Therefore, even if the release button 4b is half-pressed by the photographer, if the focus ring 12 is operated, the state in which the braking force is applied is maintained because there is an intention to perform the focus adjustment manually. , Manual focus adjustment is made possible.

  On the other hand, if the focus ring 12 has not been operated, the process proceeds to step S2, and in step S2, the braking force applied by the brake mechanism 60 is released. That is, the brake switching mechanism 62 applies a voltage to the coil assembly 72 (FIG. 6) of the brake mechanism 60, and thereby magnetizes each core 70b of the core assembly 70. As a result, the attracting magnet 74 attached to the movable disk 64 is attracted to the tip of each core portion 70b against the biasing force of the biasing coil spring 68. As a result, as shown in FIG. 7, the disk portion 64a of the movable disk 64 is separated from the friction disk 18b of the drive motor 18, and the braking force applied by the brake mechanism 60 is released.

  FIG. 12 is a time chart showing a voltage applied to the coil assembly 72 of the brake mechanism 60 by the brake switching mechanism 62. As shown in FIG. 12, before the automatic focusing is started (before time t0), no voltage is applied to the brake mechanism 60, and the brake mechanism 60 is in a state where a braking force is applied. Next, when step S2 in FIG. 11 is executed at time t0, the brake switching mechanism 62 applies the initial applied voltage V1 to the brake mechanism 60 to magnetize each core 70b. This initial applied voltage V1 is applied for about 20 msec in the present embodiment. During this time, the movable disk 64 pressed against the friction disk 18b (FIG. 6) is separated from the friction disk 18b and is attracted to each core portion 70b (FIG. 7), so that the braking force is released. At time t1 after the application of the initial applied voltage V1 for about 20 msec, the applied voltage is reduced to a holding voltage V2 lower than the initial applied voltage V1 and is maintained as it is. That is, when starting the suction of the movable disk 64, the tip of each core portion 70b and the attraction magnet 74 are largely separated from each other. Need to occur. After the initial applied voltage V1 is applied for a predetermined time, the attracting magnet 74 is attracted to the tip of each core portion 70b. Therefore, even if the applied voltage is reduced to the holding voltage V2 and the current flowing through the coil assembly 72 is reduced. The state in which the attracting magnet 74 is attracted can be maintained. Thus, power consumption by the brake mechanism 60 can be reduced.

  Next, in step S3 of FIG. 11, it is determined again whether or not the photographer has operated the focus ring 12. That is, even after the brake force by the brake mechanism 60 is released in step S2, if the photographer operates the focus ring 12, the process proceeds to step S8, where the application of the brake force is restored, and the manual focus operation is performed. enable. On the other hand, when the focus ring 12 is not operated, the process proceeds to step S4.

  In step S4, the drive motor 18 is driven by the automatic focus control unit 14, and the automatic focus operation is started (the hatched portion in FIG. 12). At this time, since the braking force by the brake mechanism 60 has been released, the automatic focusing operation by the driving motor 18 can be smoothly performed. Next, in step S5, it is further determined whether or not the photographer has operated the focus ring 12. When the focus ring 12 is operated, even during the automatic focusing operation started in step S4, the driving motor 18 is stopped (step S7), and the application of the braking force is restored (step S7). S8) Manual focus operation is enabled. On the other hand, when the focus ring 12 is not operated, the automatic focus operation is continued.

  When focusing is performed by the automatic focusing operation in step S6 (time t2 in FIG. 12), the application of the braking force is restored in step S8 (time t3 to t4 in FIG. 12), and one process of the flowchart in FIG. finish. That is, when the brake switching mechanism 62 stops applying the voltage to the brake mechanism 60, the magnetism of each core portion 70b is lost. As a result, the disk portion 64a of the movable disk 64 is pressed against the friction disk 18b by the biasing force of the biasing coil spring 68 (FIG. 6), and a braking force is applied to the drive motor 18. Thus, the state returns to the state before the execution of the flowchart in FIG.

  According to the lens drive mechanism 10 of the first embodiment of the present invention, the application / release of the braking force is switched based on the operation on the focus ring 12 and / or the release button 4b (automatic focus operation unit) (FIG. 11). By stopping the sun gear 38 by the braking force of the brake mechanism 60, the manual focus can be reliably operated via the planetary gear mechanism 34 even when the driving motor 18 having a low self-holding force is used. . On the other hand, when performing automatic focusing, the braking force is released (steps S2 to S6 in FIG. 11), so that the drive motor 18 drives the focus lens drive ring 22 against unnecessary rotation resistance. There is no need to perform smooth automatic focusing. Thus, even when a driving motor having a small self-holding force is used, a smooth focus adjustment can be performed in a full-time manual mode.

  Further, according to the lens driving mechanism 10 of the present embodiment, the brake mechanism 60 is configured to apply the braking force even in the non-energized state (FIG. 6). Stops reliably. Therefore, even when the power of the lens unit 2 and the camera 1 is off, the user can perform the focus adjustment by operating the focus ring 12.

  Further, according to the lens driving mechanism 10 of the present embodiment, the brake switching mechanism 62 is configured to apply the braking force when the focus ring 12 is operated even during the execution of the focusing by the automatic focusing. Since the brake mechanism 60 is switched (steps S5 → S7 → S8 in FIG. 11), the photographer can shift to the manual focus without any special switching operation.

  Further, according to the lens driving mechanism 10 of the present embodiment, since the differential transmission mechanism is constituted by the planetary gear mechanism 34 (FIG. 5), the input gear 42 (first gear) or the sun gear 38 (second gear). ) Can be reliably transmitted to the output gear 44, and a reliable full-time manual operation can be realized.

  Next, a lens driving mechanism according to a second embodiment of the present invention will be described with reference to FIG. In the above-described first embodiment, the planetary gear mechanism is used as the differential transmission mechanism that outputs the input from the sun gear and the input gear from the output gear. However, in the lens driving mechanism according to the second embodiment of the present invention, The second embodiment differs from the first embodiment in that a different mechanism is employed. Therefore, here, only the points of the second embodiment of the present invention that are different from the first embodiment will be described, and description of the same configuration, operation, and effect will be omitted.

  FIG. 13 is an enlarged sectional view of the differential transmission mechanism employed in the lens driving mechanism according to the second embodiment of the present invention.

  As shown in FIG. 13, the differential transmission mechanism 134 in the present embodiment includes a sun friction wheel 138 that is a sun rotation member, and three planets that are planetary rotation members arranged to be in contact with the sun friction wheel 138. It has a sphere 140, a rotation input member 142 arranged to be in contact with these planetary spheres 140, and an output gear 144 as a rotation output member. The output gear 144 is rotatably supported by an output gear support shaft 152 that is an output member support shaft. Further, the differential transmission mechanism 134 has a first radial bearing 154a rotatably supporting the transmission rotary shaft 132a at an end on the worm wheel 132 side, and a rotatable transmission rotary shaft 132a at the end on the output gear 144 side. It has a second radial bearing 154b for supporting, and a third radial bearing 156 for rotatably supporting the output gear 144.

  The differential transmission mechanism 134 provided with these members allows the planetary sphere 140 to rotate the rotation input from the rotation input member 142 as the first input unit and the rotation input from the sun friction wheel 138 as the second input unit. The rotation according to the difference is output from the output gear 144 as an output unit, and functions as a differential transmission mechanism. Also in the lens driving mechanism of the present embodiment, during manual focusing, the rotation input member 142 is rotated in a state where the sun friction wheel 138 is stopped by the braking force of the brake mechanism 60, and the rotation of the rotation input member 142 is controlled by the output gear. 144. Further, at the time of automatic focusing, as in the first embodiment, the sun friction wheel 138 is rotated with the rotation input member 142 stopped, and the rotation of the sun friction wheel 138 is transmitted to the output gear 144.

  The sun friction wheel 138 is a friction wheel formed integrally with the worm wheel 132, and is rotated integrally with the worm wheel 132 about the transmission rotation shaft 132a. Further, an end of the transmission rotating shaft 132a on the worm wheel 132 side is rotatably supported by a first radial bearing 154a embedded in the second housing 148, and an end of the transmission rotating shaft 132a on the side of the sun friction wheel 138 is provided. , Are rotatably supported by a second radial bearing 154b embedded in the output gear 144.

  The planetary spheres 140 are three spheres arranged around the sun friction wheel 138, and are configured to rotate with the rotation of the sun friction wheel 138 by rolling on the outer peripheral surface of the sun friction wheel 138. I have. Each planetary sphere 140 is rotatably attached to three planetary sphere shafts 144a formed to protrude from the end face of the output gear 144. These three planetary sphere shafts 144a are provided around the center axis of the output gear 144 at intervals of 120 °. Thus, when the sun friction wheel 138 is rotated, each planetary sphere 140 rolling on the outer peripheral surface is rotated about the planetary sphere axis 144a.

  The rotation input member 142 is an annular member arranged so as to surround the planetary sphere 140, and is supported so as to be rotatable around the same axis as the sun friction wheel 138. A rolling surface 142a is formed on the inner periphery of the rotation input member 142 so that each planetary sphere 140 rolls on the surface, and outer teeth 142b are formed on the outer periphery so as to mesh with the idler gear 30 (FIG. 3). I have. Thus, the rotation of the idler gear 30 is transmitted to each planetary sphere 140 via the rotation input member 142.

  The output gear 144 has the same configuration as the output gear 44 in the first embodiment except that three planetary sphere shafts 144a, which are planet support shafts, are formed on the end face on the side of the sun friction wheel 138. The structure for supporting the transmission rotary shaft 132a is the same as that of the first embodiment. As shown in FIG. 6, both ends of the transmission rotating shaft 132a are supported by a first radial bearing 154a and a second radial bearing 154b, respectively.

  Further, since torque is transmitted to the worm wheel 132 via the worm 136, a thrust direction force acts on the worm wheel 132 together with the rotational force. The thrust force acting on the worm wheel 132 is supported by both ends of the transmission rotation shaft 132a to which the worm wheel 132 is fixed, and the axial movement of the transmission rotation shaft 132a is restricted. That is, the end surface of the transmission rotary shaft 132a on the worm wheel 132 side contacts the bottom surface 148a of the concave portion of the second housing 148 that receives the first radial bearing 154a, and the axial movement of the transmission rotary shaft 132a is restricted. . On the other hand, the end face of the transmission rotation shaft 132a on the side of the sun friction wheel 138 contacts the bottom surface 144c of the concave portion of the output gear 144 that receives the second radial bearing 154b, and the axial movement of the transmission rotation shaft 132a is restricted. .

  Further, the axial force acting on the output gear 144 is supported by the distal end surface of the output gear support shaft 152 abutting against the bottom surface 144d of the concave portion of the output gear 144 that receives the third radial bearing 156.

  The end faces on both sides of the transmission rotation shaft 132a are formed in a spherical shape as in the first embodiment. Therefore, each end face of the transmission rotation shaft 132a substantially makes point contact with the bottom surface 148a and the bottom surface 144c on the center axis of the transmission rotation shaft 132a. Similarly, the distal end surface of the output gear support shaft 152 is also formed in a spherical shape, and the distal end surface of the output gear support shaft 152 substantially makes point contact with the bottom surface 144d on the center axis of the output gear support shaft 152. .

  The preferred embodiment of the present invention has been described above, but various changes can be made to the above-described embodiment. In particular, in the above-described embodiment, the present invention is applied to a full-time manual still camera, but the lens driving mechanism of the present invention is applied to moving a lens built in binoculars, a video camera, a telescope, and the like. You can also.

A Optical axis 1 Camera 2 Lens unit 4 Camera body 4a Image sensor surface 4b Release button (automatic focus operation unit)
6 lens barrel 8 lens 10 lens drive mechanism 12 focus ring (manual focus operation unit)
Reference Signs List 14 auto focus controller 16 focus lens 18 drive motor 18a motor output shaft 18b friction disk 20 manual operation ring 20a gear teeth 22 focus lens drive ring (lens moving mechanism)
22a Gear teeth 24 Manual focus operation detection gear 24a Encoder wheel 26 First slip gear 28 Second slip gear 28a Slip spring 30 Idler gear 30a Brake spring 30b Friction plate 32 Worm wheel 32a Transmission rotating shaft 34 Planetary gear mechanism (differential transmission mechanism)
36 Worm 38 Sun gear (second input unit, second gear)
40 planetary gear (planetary rotating member)
42 input gear (first input unit, first gear)
42a inner peripheral teeth 42b outer peripheral teeth 44 output gear (output unit, output gear)
44a Planetary gear shaft (planetary support shaft)
44b Output gear teeth 44c Bottom (thrust support)
44d bottom (thrust support)
46 first housing 48 second housing 48a bottom surface (thrust support)
50 detection sensor 52 output gear support shaft (output member support shaft)
54a first radial bearing 54b second radial bearing 56 third radial bearing 60 brake mechanism 62 brake switching mechanism 64 movable disk 64a disk portion 64b cylindrical portion 66 guide shaft 66a shaft boss 68 biasing coil spring 70 core assembly 70a base 70b Core part 72 Coil assembly 72a Flexible board 72b Cylindrical coil 72c, 72d Circuit pattern 74 Attraction magnet 74a Yoke 74b Spacer 132 Worm wheel 132a Transmission rotating shaft 134 Differential transmission mechanism 136 Worm 138 Sun friction wheel (second input unit)
140 planet sphere (planetary rotating member)
142 rotation input member (first input unit)
142a Rolling surface 142b Outer teeth 144 Output gear (output unit)
144a Planetary sphere axis (planet support axis)
144b Output gear teeth 144c Bottom (thrust support)
144d bottom (thrust support)
146 First housing 148 Second housing 148a Bottom surface (thrust support)
152 Output gear support shaft (output member support shaft)
154a First radial bearing 154b Second radial bearing 156 Third radial bearing

Claims (8)

A lens driving mechanism for driving a focus lens for performing focusing, and
A first driving force transmitting unit that transmits a driving force based on a user operation for manually driving the focus lens;
A second driving force transmitting unit that transmits a driving force of a driving motor for automatically driving the focus lens;
An output unit that outputs a driving force for moving the focus lens in the optical axis direction based on the driving force transmitted from the first driving force transmission unit or the second driving force transmission unit;
A brake mechanism for stopping transmission of the driving force by the second driving force transmission unit when the driving force is transmitted from the first driving force transmission unit to the output unit;
A brake switching mechanism that switches between stopping and canceling the transmission of the driving force by the second driving force transmitting unit,
A detection unit that detects transmission of the driving force to the first driving force transmission unit by the user operation,
The brake switching mechanism is configured to control the brake mechanism so that a braking force is applied to an output shaft of the driving motor when the detection unit detects the transmission of the driving force to the first driving force transmission unit. A lens drive mechanism characterized by switching .   2. The brake mechanism according to claim 1, wherein the transmission of the driving force by the second driving force transmission unit is stopped while the driving force is transmitted from the first driving force transmission unit to the output unit. 3. Lens drive mechanism. The brake switching mechanism, while the transmission of the driving force to said first driving force transmitting portion is not detected by the detection unit, and cancels the stop of the transmission of the driving force by the second driving force transmission unit, according to claim 1 or 3. The lens drive mechanism according to 2. The above-mentioned brake switching mechanism,
While the power from the driving motor is being transmitted to the second driving force transmission unit, the brake mechanism is switched so as to cancel the stop of the transmission of the driving force by the second driving force transmission unit,
Even while the power from the driving motor is being transmitted to the second driving force transmission unit, while the transmission of the driving force to the first driving force transmission unit is being detected by the detection unit, , switching the brake mechanism to stop the transmission of the driving force by the second driving force transmitting portion, the lens drive mechanism according to claim 1 or 2. The lens drive according to any one of claims 1 to 4 , further comprising a driving force transmitting unit that transmits driving force from the first driving force transmitting unit and the second driving force transmitting unit to the output unit. mechanism. The first driving force transmission unit includes a first gear that rotates according to the user operation,
The second driving force transmission unit includes a second gear that rotates based on the driving force transmitted from the driving motor ,
The output unit includes an output gear,
6. The lens driving mechanism according to claim 5 , wherein the driving force transmission unit is configured by a planetary rotation member that transmits rotation of the first gear and the second gear to the output gear. A lens unit capable of manual and automatic focusing,
A lens barrel,
A lens disposed inside the lens barrel,
A lens driving mechanism according to any one of claims 1 to 6 ,
A lens unit comprising: A manual and automatic focusing camera,
A camera body,
The lens unit according to claim 7 attached to the camera body,
A camera comprising:

Images