JP4501654B2 - Zoom lens device and portable electronic device - Google Patents

Description

  The present invention relates to a zoom lens device that is mounted on a camera or the like and has a plurality of lens groups, and more particularly, to a zoom lens device that includes a zoom mechanism that changes the position of the lens group in a step shape.

  A step zoom mechanism in which a plurality of lens groups are mounted on a camera in which a plurality of lens groups are moved between a short focal length position (wide position) and a long focal length position (tele position). The multifocal magnification switching lens barrel provided is disclosed in Patent Document 1. In this multifocal magnification switching lens barrel, a fixed cylinder is inserted into a rotating cylinder, and a first moving cylinder holding a front group lens and a second moving cylinder holding a rear group lens are inserted into the fixed cylinder. Has been.

  The rotary cylinder is provided with a zoom lens cam groove for the front lens group and a zoom cam groove for the rear lens group for guiding the first and second movable cylinders, respectively. The fixed cylinder is formed with a focus adjustment cam groove having an inflection portion and a guide groove for guiding the first moving cylinder. A cam pin that engages with the magnification change cam groove and the guide groove for the front group lens is formed in the first moving cylinder, and the magnification change cam groove and the focus adjustment cam groove for the rear group lens are formed. An engaging cam pin is formed on the second movable cylinder.

  Further, a gear portion is provided on the outer peripheral surface of the rear end portion of the rotary cylinder, and the rotary cylinder rotates about the optical axis as a rotation axis by driving of a motor. By rotating the rotating cylinder, zooming and focus adjustment are performed simultaneously.

  That is, when the rotating cylinder is slightly rotated to the feeding side, the first moving cylinder moves linearly along the guide groove of the fixed cylinder, but the second moving cylinder is at the inflection portion of the focus adjustment cam groove. It bends and the amount of movement in the optical axis direction is smaller than that of the first moving cylinder. During this time, there is no change in the magnification of the lens system, and focus adjustment is performed from an infinite distance to a close distance in a wide state. As described above, the zooming and the focus adjustment at each zooming position are performed by the same drive source, thereby realizing a reduction in size and cost of the camera.

  However, such a multifocal magnification switching lens barrel is provided with a zoom cam groove, a focus adjustment cam groove, and a guide groove in a rotating cylinder, and is incorporated in a portable electronic device such as a mobile phone. When mounted on an ultra-small camera, it is difficult to form each groove because the rotating cylinder is too small.

  Therefore, it is conceivable to employ a zoom lens device provided with a cam so that the ultra-small camera has a step zoom mechanism. As shown in FIG. 8, the zoom lens device includes a motor 1 as a driving source, a cam 3 formed by a spiral rib projecting from a cylindrical rotating shaft 2, and light on the image sensor 4. A lens system A arranged on the axis Z is provided.

  Gears (hereinafter referred to as “first gear” and “third gear”) 5 and 6 are attached to the rotation shaft of the motor 1 and the rotation shaft of the cam 3. The first and third gears 5 and 6 mesh with an intermediate gear (hereinafter referred to as “second gear”) 7 to transmit the rotational force, but the second gear 7 is omitted and the first gear is omitted. The gear 5 and the third gear 6 may be directly meshed with each other.

  A surface on the outside (left side in the drawing) of the cam 3 is a zoom cam surface 8 and a surface on the back side (right side in the drawing) is a focusing cam surface 9. A plurality of (here, five) flat portions and inclined portions are alternately formed on the zoom cam surface 8. The focusing cam surface 9 is formed only with an inclined portion.

  In the lens system A, the first lens group 11, the second lens group 12, and the third lens group 13 are arranged on the optical axis Z from the outer side to the inner side, and the third lens group 13 and the imaging element 4 face each other. ing. The role of the second lens group 12 is mainly to change the focal length of the lens system A (zoom operation), and the role of the third lens group 13 is to mainly adjust the imaging position of the lens system A, that is, the image sensor 4. Focusing (focusing operation).

  The first lens group 11 is held by a holding frame (not shown) that does not move. The second lens group 12 and the third lens group 13 are each a holding frame (hereinafter referred to as a “second holding frame” or a “third holding frame”) 14 that individually moves in the same direction as the optical axis Z. 15 is held.

  A pair of guide shafts 16 and 16 pass through the second holding frame 14 and the third holding frame 15, and both the holding frames 14 and 15 are guided by the guide shafts 16 and 16 and moved. However, one guide shaft 16 has a biasing means 18 such as a compression spring for joining the zoom follower portion 17 provided on the second holding frame 14 to the zoom cam surface 8, and a third holding frame. An energizing means 18 such as a compression spring for joining the focus follower portion 19 provided at 15 to the focus cam surface 9 is wound. Therefore, the cam 3 is always sandwiched between the zoom follower portion 17 and the focus follower portion 19.

  The zoom lens apparatus is configured as described above, and the operation will be described with reference to FIG. When the motor 1 rotates, this driving force is transmitted to the rotating shaft 2 of the cam 3 by the first, second, and third gears 5, 7, and 6, and the cam 3 rotates. Then, the joint portion between the zoom follower portion 17 and the zoom cam surface 8 and the joint portion between the focus follower portion 19 and the focus cam surface 9 move outward or in the rearward direction along the same direction as the optical axis Z. To do.

  However, since the zoom cam surface 8 is formed with alternating flat portions and inclined portions, the zoom follower portion 17 moves while moving on the flat portion as shown by the solid line in FIG. It does not move in the outward direction but moves in the outward direction only while moving on the inclined part. Accordingly, the zoom follower unit 17 and the second lens group 12 move in a step shape, and a zoom operation is performed.

On the other hand, since the focus cam surface 9 is formed only of the inclined portion, the focus follower portion 19 continuously moves outward as indicated by a broken line in FIG. Therefore, even if the motor 1 continues to rotate and the cam 3 continues to rotate, the zoom follower portion 17 is joined to the flat portion of the zoom cam surface 8 and the second lens group 12 is stopped. The focusing operation is performed by moving the third lens group 13. Thus, according to this zoom lens apparatus, both the zoom and focus operations are performed by the single motor 1.
JP-A-9-329733

  In the zoom lens device described above, if the number of steps is set so as to correspond to various zooms, the number of flat portions of the zoom cam surface 8 is increased, the diameter of the zoom cam 3 is increased, and the size is reduced. Disadvantageous. On the other hand, if the number of steps is reduced, the size can be reduced, but the zoom pattern that can be handled is limited, and the value as a zoom lens device is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a zoom lens device capable of performing a zoom operation with the number of steps that can sufficiently achieve the value as a zoom lens while achieving downsizing.

  A zoom lens device according to the present invention includes a lens system in which a plurality of lens groups are arranged on an optical axis, and a zoom mechanism that changes the focal length of the lens system by moving one or more lens groups in the same direction as the optical axis. A focus mechanism that adjusts the imaging position of the lens system by moving one or more lens groups in the same direction as the optical axis, and a drive that transmits driving force from one drive source to the zoom mechanism and the focus mechanism A zoom lens device comprising force transmitting means, wherein the driving force transmitting means includes an intermittent transmission mechanism that intermittently transmits the driving force from the driving source to the zoom mechanism. Yes.

  According to this zoom lens apparatus, even if there is only one drive source, the intermittent transmission mechanism causes the zoom mechanism to repeat the state where one or more lens groups are stopped and the state where it is moved in a stepped manner. A focus mechanism moves one or more lens groups continuously in the same direction as the optical axis. In a state where the lens group for changing the focal length is stopped by the intermittent transmission mechanism, only one focusing operation can be performed by moving one or more other lens groups by the focusing mechanism. That is, according to this zoom lens device, since the so-called step zoom operation is realized by the intermittent transmission mechanism, it is not necessary to provide a flat portion on the cam traced by the zoom mechanism as in the conventional example. It is possible to reduce the size while having the number of steps that can sufficiently exhibit the value as a lens.

  In the zoom lens device, it is preferable that the intermittent transmission mechanism is a Geneva mechanism.

  The Geneva mechanism is a combination of a prime mover and a follower, and the prime mover has an arc-shaped convex portion and is provided with one pin outside the arc-shaped convex portion. The driven wheel is formed with an arcuate concave surface that engages with the arcuate convex surface and a plurality of radial grooves into which the pins are engaged. When the driving force of one drive source is transmitted to the prime mover and the pin of the rotating prime mover is engaged in the radial groove of the follower, the follower rotates and the pin comes off the radial groove. The follower stops. When the driven vehicle is rotating, the zoom operation is performed by moving the lens group. On the other hand, when the driven vehicle is stopped, the zoom operation is stopped by stopping the lens group. That is, this lens group is moved stepwise by the Geneva mechanism, and a zoom operation is performed. The focus mechanism operates while the lens group is stopped, and the focus operation is performed by moving the lens group.

  Therefore, according to this zoom lens device, the intermittent transmission mechanism is configured by a Geneva mechanism, and the number of steps of step zoom can be set according to the number of radial grooves installed in the driven vehicle. It is possible to cope with a large number of steps without increasing the diameter of the vehicle, and it is advantageous for downsizing without sacrificing the usability as a zoom lens.

  In the zoom lens device, the intermittent transmission mechanism may be a parallel index cam mechanism.

  The parallel index cam is a combination of a prime mover and a follower, and the prime mover is a plate cam formed with a bulge, and the follower is concentrically shaped with a plurality of pins joined to the plate cam. Projected to The driving force of one drive source is transmitted to the prime mover, and the driven vehicle rotates only while the bulge of the prime mover applies rotational force to the pin of the follower, and is driven when the bulge is removed from the pin. The car stops. When the driven vehicle is rotating, the zoom operation is performed by moving the lens group. On the other hand, when the driven vehicle is stopped, the zoom mechanism is stopped by stopping the lens group. That is, this lens group is moved stepwise by a parallel index cam mechanism, and a zoom operation is performed. The focus mechanism operates while the lens group is stopped, and the focus operation is performed by moving the lens group.

  Therefore, according to this zoom lens device, since the intermittent transmission mechanism is constituted by the parallel index cam mechanism, the play of the cam mechanism can be reduced while having a simple configuration, which is advantageous in performing a more accurate zoom operation. It becomes.

  Further, in the zoom lens device, the zoom mechanism includes a zoom follower portion provided on a holding frame that holds a lens group for changing the focal length, and a helical zoom provided on the intermittent transmission mechanism. It is preferable that a zoom cam surface and a biasing means for joining the zoom follower portion to the zoom cam surface are preferably provided.

  According to this zoom lens device, the zoom follower portion provided on the holding frame that holds the lens group is joined to the spiral zoom cam surface by the urging means, and this joined portion is in the same direction as the optical axis. By moving, the lens group held by the holding frame moves on the optical axis. Since the spiral zoom cam surface rotates intermittently by the intermittent transmission mechanism, the holding frame also moves intermittently in the same direction as the optical axis, and the lens group held by this holding frame steps on the optical axis. Move to the shape.

  Further, in the zoom lens device, the focus mechanism includes a focus follower portion provided on a holding frame that holds a lens group for adjusting the imaging position, and an optical axis by a driving force of the driving force transmitting unit. It is preferable that a moving body that moves in the same direction as the moving body and a biasing unit that joins the focus follower to the moving body.

  According to this zoom lens device, the focus follower provided on the holding frame that holds the lens group is joined to the moving body by the urging means, and the moving body moves in the same direction as the optical axis to move the moving frame to the holding frame. The held lens continuously moves on the optical axis. Accordingly, even while the lens group for the zoom operation is stopped by the zoom mechanism, the lens group for the focus operation is continuously moved by the focus mechanism to perform the focus operation.

  Further, in the zoom lens device, the focus mechanism includes a focus follower portion provided on a holding frame that holds a lens group for adjusting the imaging position, and an optical axis by a driving force of the driving force transmitting unit. And a spiral focusing cam surface that rotates about the same direction as the rotation axis, and an urging means for joining the focusing follower portion to the focusing cam surface.

  According to this zoom lens apparatus, the focus follower portion provided on the holding frame that holds the lens group is joined to the spiral focus cam surface by the urging means, and the focus cam surface is rotated to rotate the focus lens. The joint surface between the follower portion and the focus cam surface moves nonlinearly in the same direction as the optical axis. Therefore, even when the lens group for the zoom operation is stopped by the zoom mechanism, the lens group for the focus operation moves non-linearly on the optical axis by the focus mechanism to perform the focus operation. In order to prevent the focus follower part from coming off the spiral focus cam surface, the speed of moving the lens for focus operation is slower than the speed of moving the lens for zoom operation. Has been.

  According to the present invention, since the intermittent transmission mechanism that intermittently transmits the driving force from one drive source to the zoom mechanism is provided, the zoom mechanism has a simple configuration, as in the conventional example. There is no need to provide a flat portion on the cam to be traced, and it is possible to reduce the size while having the number of steps that can fully exhibit the value as a zoom lens. Accordingly, a zoom lens device having a step zoom function can be mounted on an ultra-small camera provided in a portable electronic device such as a mobile phone.

[Embodiment 1]
A zoom lens apparatus according to a first embodiment of the present invention will be described with reference to FIGS. In addition, the same part and the same equivalent part as the past are attached | subjected and demonstrated with the same code | symbol. This zoom lens apparatus includes a lens system A, a driving force transmission means B, a focus mechanism C, an intermittent transmission mechanism D, and a zoom mechanism E.

  As shown in FIG. 1, the lens system A includes a first lens group 11, a second lens group 12, and a first lens group arranged on the optical axis Z from the outside (left side in FIG. 1) to the back side (right side in FIG. 1). The third lens group 13 is opposed to the image sensor 4. The first lens group 11 is held by a holding frame (not shown) that does not move. The second lens group 12 and the third lens group 13 are held by a second holding frame 14 and a third holding frame 15 that move individually. A pair of guide shafts 16, 16 pass through the second and third holding frames 14, 15, and the second lens group 12 and the third lens group 13 are restricted by the guide shaft 16 and are on the optical axis Z. Has been moved to.

  When the second lens group 12 and the third lens group 13 are moved, the lens system A changes the focal length (zoom operation) and adjusts the imaging position of the lens system A, that is, applies to the image sensor 4. Focusing (focusing operation) is performed. However, the second lens group 12 mainly plays a role of a zoom operation, and the third lens group 13 mainly takes a role of a focus operation.

  Although not shown, the second lens group 12 can perform the focusing operation, and the third lens group 13 can perform the zoom operation. Further, the lens system A includes the fourth lens group and the like. In this case, two or more lens groups may play a role of a zoom operation or a focus operation.

  And the driving force transmission means B is provided with the feed screw 20 etc. to which the driving force from the motor 1 which is one drive source is transmitted. The feed screw 20 is arranged in the same direction as the optical axis Z, and a second gear 7 that meshes with the first gear 5 attached to the motor 1 is attached to the back end, and the motor 1 rotates. Thus, the feed screw 20 is rotated. A focus mechanism C is provided on the feed screw 20.

  The focus mechanism C includes a moving body 21 such as a nut screwed to the feed screw 20, a focus follower portion 19 provided on the third holding frame 15, and the focus follower portion 19 as a moving body 21. And an urging means 18 such as a compression spring to be joined to the outer side surface. The biasing means 18 is wound around one guide shaft 16 so as to be interposed between the second holding frame 14 and the third holding frame 15.

  When the feed screw 20 rotates, the moving body 21 and the third holding frame 15 continuously move by a minute distance in the same direction as the optical axis Z. The position of the third holding frame 15 is detected by the sensor 22. This sensor 22 is connected to the controller 23. The controller 23 is connected to the power source 24 and the motor 1 and controls the rotation of the motor 1.

  A driving shaft 25 is provided in parallel with the feed screw 20. A third gear 6 that meshes with the second gear 7 is attached to the inner end of the driving shaft 25. The feed screw 20 and the drive shaft 25 can be shortened by making the feed screw 20 and the drive shaft 25 separate, but by forming a male screw on the drive shaft 25, The feed screw 20 and the driving shaft 25 can be integrated to save space.

  An intermittent transmission mechanism D is provided at the outer end of the driving shaft 25. The intermittent transmission mechanism D is configured by a Geneva mechanism F. In the Geneva mechanism F, a driving vehicle 26 attached to the outer end portion of the driving shaft 25 and a driven vehicle 28 attached to the driven shaft 27 are combined. The driven shaft 27 is arranged in parallel with the driving shaft 25.

  As shown in FIG. 2, the prime mover 26 is formed with a protruding portion 31 including an arc-shaped convex portion 29 and an arc-shaped concave portion 30, and a pin 32 is provided outside the arc-shaped concave portion 30. . On the other hand, the driven wheel 28 has a plurality of (five in the drawing) in which the circular arc-shaped concave surface 34 engaged with the circular arc-shaped convex portion 29 and the pin 32 are engaged with a disk 33 fixed to the driven shaft 27. However, the radial grooves 35, 35... Are formed at a constant angle θ.

  When the feed screw 20 rotates, the second gear 7 and the third gear 6 mesh with each other, whereby the driving shaft 25 rotates. Then, the pin 32 of the prime mover 26 rotates continuously. However, the driven wheel 28 rotates only while the pin 32 is engaged in the radial groove 35. That is, the driven vehicle 28 rotates intermittently.

  Such a driving force from the intermittent transmission mechanism D is transmitted to the zoom mechanism E. The zoom mechanism E includes a zoom follower portion 17 provided on the second holding frame 14, a zoom cam surface 36 formed in a spiral on the driven shaft 27, and the zoom follower portion 17 as a zoom cam surface. And a biasing means 18 such as a compression spring to be joined to 36. The urging means 18 is the same as the urging means 18, and the zoom follower portion 17 is always joined to the zoom cam surface 36.

  Therefore, when the driven shaft 27 and the driven wheel 28 rotate, the joint between the zoom follower portion 17 and the zoom cam surface 36 moves in the same direction as the optical axis Z, and the second lens group 12 moves to the optical axis Z. Move up. However, since the driven vehicle 28 rotates intermittently as described above, the zoom cam surface 36 also rotates intermittently, and the second lens group 12 moves intermittently on the optical axis Z.

  Here, the positional relationship among the second or third lens holding frames 14 and 15, the moving body 21, the driving vehicle 26 and the driven vehicle 28 will be described with reference to FIG. 2. The moving body 21, the driving vehicle 26 and the driven vehicle 28 are arranged in a line, and the line connecting these center lines is parallel to the line connecting the pair of guide shafts 16, 16 penetrating the holding frames 14, 15. Thus, the zoom lens device is reduced in size. Therefore, when there is room in the zoom lens device, the moving body 21, the driving vehicle 26, and the driven vehicle 28 may be arranged in a triangular shape.

  In any case, the diameter of the follower wheel 28 in which the five radial grooves 35, 35... Are formed in the follower wheel 28 at a constant angle θ and the second lens group 12 is moved in five steps. This is half of the cam 3 having five flat portions (illustrated by a two-dot chain line) as described in the background art.

  Next, the operation of the zoom lens apparatus according to the first embodiment configured as described above will be described. When the motor 1 rotates in the counterclockwise direction CCW as viewed in the X direction of FIG. 1, the first gear 5 rotates in the counterclockwise direction CCW, and the second gear 7 meshed with the first gear 5 Rotate clockwise CW. Then, the feed screw 20 rotates, the moving body 21 moves outward from the back side, and the third holding frame 15 and the third lens group 13 joined to the moving body 21 by the focus follower portion 19 are As shown by a broken line in FIG.

  In parallel with this operation, the third gear 6 meshed with the second gear 7 rotates counterclockwise CCW, and the driving shaft 25 also rotates counterclockwise CCW, whereby the intermittent transmission mechanism D is activated. To do. That is, as shown in FIG. 3 (a), the driven vehicle 28 is rotated counterclockwise CCW until the pin 32 is engaged with the adjacent radial groove 35 from the radial groove 35 with the pin 32. It has stopped. Accordingly, the second holding frame 14 and the second lens group 12 are stopped as indicated by q1 to q2 in FIG. 4, and only the third lens group 13 is moved so that the focal length is not changed. Only operation is performed.

  Subsequently, as shown in FIG. 3B, the pin 32 provided on the rotating driving vehicle 26 is engaged in the radial groove 35, so that the driven vehicle 28 is rotated clockwise by an angle θ. To do. During this time, the driven shaft 27 also rotates by the angle θ, and the helical zoom cam surface 36 rotates, so that the second holding frame 14 and the second lens group 12 are as indicated by q2 to q3 in FIG. Move and zoom operation is performed.

  Subsequently, as shown in FIG. 3C, until the pin 32 is detached from the radial groove 35 and is engaged with the adjacent radial groove 35, only the driving vehicle 26 rotates and the driven vehicle 28 is rotated as described above. Does not rotate. Accordingly, the second lens group 12 is stopped as indicated by q3 to q4 in FIG. 4, and only the third lens group 13 is moved, and only the focusing operation is performed.

  Thus, even if the motor 1 continues to rotate counterclockwise CCW, the driven vehicle 28 and the driven shaft 27 rotate intermittently and are joined to the zoom cam surface 36 provided on the driven shaft 27. The zoom follower portion 17 and the second lens group 12 of the second holding frame 14 are moved stepwise from the back side toward the outside. On the other hand, since the third lens group 13 moves continuously, the focusing operation is performed accurately.

  Conversely, when the motor 1 rotates in the clockwise direction CW, the second lens group 12 moves stepwise from the outside to the back side, and the third lens group 13 moves continuously from the outside to the inside. As a result, the zoom operation and the focus operation are performed as described above.

Thus, since this zoom lens device drives the zoom mechanism E via the intermittent transmission mechanism D, there is no need to provide a flat portion on the cam traced by the zoom mechanism E as in the conventional example. It is possible to reduce the size while having the number of steps that can sufficiently exhibit the value as a lens. Further, the intermittent transmission mechanism D is configured by the Geneva mechanism F, so that the intermittent transmission mechanism D can be realized with a small and simple structure, which is advantageous in reducing the size of the zoom lens device.
[Embodiment 2]
Next, a second embodiment of the zoom lens apparatus according to the present invention will be described with reference to FIGS. However, the same or equivalent parts as those of the conventional and first embodiments will be described with the same reference numerals.

  The zoom lens apparatus according to the second embodiment is characterized in that the third lens group 13 moves nonlinearly. For this reason, in this zoom lens apparatus, the focus mechanism C includes a gear train 37 and a spiral focus cam surface 38.

  The gear train 37 is for reducing the rotational speed of the second gear 7, and is a small gear 39 coaxial with the second gear 7, a large gear 40 meshing with the small gear 39, and coaxial with the large gear 40. The small gear 41 and the large gear 42 that meshes with the small gear 41 are configured. A rotating shaft 43 in the same direction as the optical axis Z is fixed to the large gear 42, and a focusing cam surface 38 is provided on the rotating shaft 43.

  The focus follower portion 19 provided on the third holding frame 15 is joined to the focus cam surface 38. The focus follower portion 19 is not detached from the focus cam surface 38 by the gear train 37. The focus follower portion 19 is always joined to the cam surface by the biasing means 18. This urging means 18 includes an urging means 18 for joining the zoom follower portion 17 provided on the second holding frame 14 to the zoom cam surface 36 formed on the driven shaft 27 in the zoom mechanism E. It is also used.

  Since the other configuration is the same as that of the first embodiment, the operation will be described next. When the motor 1 rotates in the counterclockwise direction CCW as seen in the direction of the arrow X in FIG. 5, the first gear 5 rotates in the counterclockwise direction CCW, and the second gear 7 meshed with the first gear 5 is Rotate clockwise CW. Then, the rotational speed is reduced by the gear train 37, and the rotary shaft 43 rotates in the clockwise direction CW. Then, the portion where the focus cam surface 38 and the focus follower portion 19 are joined moves in the same direction as the optical axis Z from the back side to the outer side, and the third follower portion 19 provided with this focus is provided. The third lens group 13 held by the holding frame 15 moves on the optical axis Z outward from the back side.

  However, in the second embodiment, since the focus follower portion 19 moves on the focus cam surface 38, the third lens group 13 moves non-linearly as indicated by a broken line in FIG. Therefore, when the lens system A has a nonlinear optical design, the third lens group 13 of the second embodiment is smoother and more accurate than the third lens group 13 of the first embodiment. Can be moved to.

In parallel with the operation of the focus mechanism C, the third gear 6 meshing with the second gear 7 rotates in the counterclockwise direction CCW, and the driving shaft 25 also rotates in the counterclockwise direction CCW. The intermittent transmission mechanism D operates in the same manner as in the first embodiment. That is, as shown in FIG. 3, the driven wheel 28 and the driven shaft 27 rotate only while the pin 32 rotates while being engaged in the radial groove 35, and the zoom provided on the driven shaft 27 is rotated. The second holding frame 14 and the second lens group 12 urged by the cam surface 36 move stepwise from the back side to the outside as shown by the solid line in FIG. In this way, the zoom operation is performed by moving the second lens group 12 in a step shape, and the focusing operation is accurately performed by moving the third lens group 13 nonlinearly as described above.
[Embodiment 3]
Next, a third embodiment of the zoom lens device according to the present invention will be described with reference to FIG. The third embodiment is characterized in that the intermittent transmission mechanism D is a parallel index cam mechanism G as shown in FIG. Other configurations are the same as those of the zoom lens device according to the first or second embodiment.

  In the parallel index cam mechanism G, a driving vehicle 44 and a driven vehicle 45 are combined, and the driving vehicle 44 is formed by forming a bulging portion 47 on a plate cam 46, and the driven vehicle 45 is joined to the plate cam 46. .. Are formed concentrically on a disk 49, and the bulging portion 47 has a rotational force on the pin 48. The follower wheel 45 is made to rotate. The driving vehicle 44 is fixed to the driving shaft 25, and the driven vehicle 45 is fixed to the driven shaft 27.

  Since the other configuration is the same as that of the first or second embodiment, the operation will be described next. When the motor 1 rotates, the driving force is transmitted to the first gear 5, the second gear 7, and the third gear 6, and the driving shaft 25 rotates, so that the driving vehicle 44 is continuously moved. Rotate.

  The driven vehicle 45 rotates only while the bulging portion 47 of the prime mover 44 applies a rotational force to the pin 48 of the driven vehicle 45, and the driven vehicle 45 stops when the bulging portion 47 comes off the pin 48. . When the follower wheel 45 is rotating, the zoom mechanism E operates and the second lens group 12 moves to perform a zoom operation.

  However, when the driven vehicle 45 is stopped, the zoom mechanism E is also stopped, and the second lens group 12 is also stopped. Thus, the second lens group 12 is moved stepwise by the parallel index cam mechanism G. On the other hand, the focus mechanism C operates while the zoom mechanism E is stopped, and the third lens group 13 moves to perform a focus operation.

  As described above, in this zoom lens apparatus, the intermittent transmission mechanism D is configured by the parallel index cam mechanism G, whereby the intermittent transmission mechanism D can be realized with a small and simple structure, and the zoom lens apparatus can be miniaturized. It will be advantageous.

  Note that the present invention is not limited to the above-described three embodiments, and can be variously modified within the scope of the technical matters described in the claims. For example, the intermittent transmission mechanism D is not limited to the Geneva mechanism F or the parallel index cam mechanism G. For example, a combination of a rotating claw and a claw wheel or a combination of a pin wheel and a gear is adopted. You can also

  The zoom lens device according to the present invention is useful in the field of portable electronic devices such as mobile phones that are required to be downsized.

1 is a schematic front view showing a first embodiment of a zoom lens device according to the present invention. 1 is a schematic side view showing a main part of a first embodiment of a zoom lens device according to the present invention. FIG. 2 is a cross-sectional view taken along line YY of FIG. 1 illustrating an intermittent transmission mechanism in the first embodiment of the zoom lens apparatus according to the present invention, where (a) is a cross-sectional view showing an initial state of operation, and (b) is a cross-sectional view. Sectional drawing which shows the state in the middle of operation | movement, (c) is sectional drawing which shows the final state of operation | movement The figure which shows the locus | trajectory of the lens group in 1st Embodiment of the zoom lens apparatus based on this invention. Schematic front view showing a second embodiment of the zoom lens device according to the present invention. The figure which shows the locus | trajectory of the lens group in 2nd Embodiment of the zoom lens apparatus based on this invention. Schematic perspective view of an intermittent transmission mechanism in a third embodiment of the zoom lens apparatus according to the present invention. Schematic front view of a conventional zoom lens device The figure which shows the locus | trajectory of the lens group in the conventional zoom lens apparatus.

Explanation of symbols

A ... Lens system B ... Driving force transmission means B ... Driving force transmission means C ... Focus mechanism D ... Intermittent transmission mechanism E ... Zoom mechanism E ... Zoom mechanism F ... Geneva mechanism G ... Parallel index cam mechanism Z ... Optical axis 1 ... Motor 11 ... First lens group 12 ... Second lens group 13 ... Third lens group 14 ... Second holding frame 15 ... Third holding frame 16 ... Guide shaft 17 ... Zoom follower section 18 ... Biasing means 19 ... Focus follower unit 21 ... Moving body 36 ... Zoom cam surface 38 ... Focus cam surface

Claims (5)

A lens system in which a plurality of lens groups are arranged on the optical axis, a zoom mechanism that changes the focal length of the lens system by moving one or more lens groups in the same direction as the optical axis, and one or more lens groups. A zoom mechanism comprising: a focus mechanism that adjusts the imaging position of the lens system by moving in the same direction as the optical axis; and a driving force transmission means that transmits a driving force from one driving source to the zoom mechanism and the focusing mechanism. In the lens apparatus, the driving force transmission means includes an intermittent transmission mechanism that intermittently transmits the driving force from the driving source to the zoom mechanism , and the intermittent transmission mechanism is a Geneva mechanism or a parallel index cam mechanism. a zoom lens and wherein the at. The zoom mechanism includes a zoom follower portion provided in a lens group for changing the focal length, a spiral zoom cam surface provided in the intermittent transmission mechanism, and the zoom cam surface on the zoom cam surface. The zoom lens apparatus according to claim 1 , further comprising an urging unit that abuts the follower portion for use. The focus mechanism includes a focus follower portion provided on a holding frame that holds a lens group for adjusting the imaging position, and a moving body that moves in the same direction as the optical axis by the driving force of the driving force transmitting means. The zoom lens apparatus according to claim 1 , further comprising: an urging unit that joins the focus follower to the moving body. The focus mechanism rotates about the same direction as the optical axis by the driving force of the driving force transmitting means provided on a holding frame that holds a lens group for adjusting the imaging position and the driving force transmitting means. 3. The zoom lens device according to claim 1 , further comprising: a spiral focusing cam surface; and a biasing unit that joins the focusing follower to the focusing cam surface. A portable electronic device on which the zoom lens device according to claim 1 is mounted.

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