JP5836660B2 - Lens barrel and camera system - Google Patents

Description

  The present invention provides a lens barrel capable of aligning a distance scale of an annular member and a position of an index of a fixed member.

  Conventionally, it has a motor that moves the focusing lens group, rotates the distance scale display indicating the focus position as the motor rotates, and the current focusing lens corresponds to the distance scale display on the fixed member as the exterior member There is a lens barrel provided with an index indicating the position of the group.

  Patent Document 1 discloses a zoom lens (lens barrel) that adjusts the position of a focusing lens group in a state where an infinite position on a distance scale display and an index of a fixed member are matched. Patent Document 2 discloses a lens barrel that adjusts the position of the focusing lens group by adjusting the rotation position of the rotation transmission ring in a state where the infinite display position of the distance scale ring matches the index. . In such a lens barrel, the position adjustment is performed in a state in which the lens barrel is attached to a tool provided with an index serving as a mark of a distance scale display instead of the exterior member so that the work for the internal position adjustment group is facilitated. An exterior member is attached to.

Japanese Patent No. 3284621 JP 2009-169052 A

  However, in such a case, there is a possibility that there is a positioning error between a tool provided with an adjustment index and an exterior part provided with an index line attached thereafter. In addition, the index line may be displayed by printing, and an error with the printing jig is also generated, and the error is further increased. If there is an error between the adjusted optical infinity position and the actual optical infinity position, the actual optical infinity that was adjusted even though the user adjusted the optical infinity position to the index line is different. There are problems such as out of focus.

  Therefore, the present invention provides a lens barrel capable of aligning the distance scale of the annular member and the position of the index of the fixed member.

  A lens barrel as one aspect of the present invention includes a focusing lens group, an annular member that moves around the optical axis by moving the focusing lens group in the optical axis direction, and a distance scale that indicates a focusing position. A distance scale display member attached to the annular member, and a fixing member having an index indicating the position of the distance scale, and the distance scale display member of the annular member is attached. A convex guide portion is provided on the surface, and the distance scale display member has a hole shape that engages with the guide portion and is movable around the optical axis and restricts movement in the optical axis direction. The distance scale display member is adjusted in position around the optical axis with respect to the annular member so as to align with the indicator of the fixing member, After the adjustment of the position with respect to the annular member is completed, the guide With screws through the engagement portion, characterized in that it is fixed to the circular ring members.

  A camera system according to another aspect of the present invention includes an imaging device body and the lens barrel attached to the imaging device body in a replaceable manner.

  Other objects and features of the present invention are illustrated in the following examples.

  ADVANTAGE OF THE INVENTION According to this invention, the lens barrel which can align with the distance scale of a ring member and the position of the parameter | index of a fixing member can be provided.

It is sectional drawing of the lens-barrel in a present Example. It is the elements on larger scale of the lens barrel in a present Example. It is a partial exploded perspective view of the lens barrel in the present embodiment. It is the elements on larger scale of the lens barrel in a present Example. It is a figure which shows the state at the time of adjustment of the distance scale plate of the lens barrel in a present Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same members are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a cross-sectional view of a lens barrel in the present embodiment, FIG. 2 is an enlarged view of a focus driving unit of the lens barrel, and FIG. 3 is an exploded perspective view of the focus driving unit. The lens barrel of the present embodiment is used as a camera system by being replaceably attached to a camera body (imaging device body) (not shown). In FIG. 1, a lens barrel 100 (zoom lens) has a mount 2 for attaching to a camera body, and the mount 2 is provided with a connector 26 for performing communication between the camera body and the lens barrel 100. It has been. The mount 2 is attached to a fixed cylinder 1 (exterior member), which is a fixing member, with screws, with a mount ring 3 interposed therebetween. The fixed cylinder 1 is fixed to the guide cylinder 4 with screws. The guide cylinder 4 has a cam cylinder 5 fitted to the outer diameter thereof, and is configured to be able to rotate at a fixed position while maintaining the position of the optical axis OA (optical axis position) by bayonet engagement. A rectilinear cylinder 6 is held by a first group roller 7 on the outer diameter of the cam cylinder 5, and a first group barrel 9 including a first group lens is further held by the rectilinear cylinder 6. The rectilinear cylinder 6 moves straight in the direction of the optical axis OA (optical axis direction) by the rotation of the cam cylinder 5.

  On the inner diameter of the guide cylinder 4, a second group moving cylinder 10 is held by a cam follower (not shown). A focus cam ring 11 is held on the inner diameter of the second group moving cylinder 10 by a cam follower (not shown). Further, a second group barrel 12 including a second group lens is integrally held on the inner diameter of the focus cam ring 11. As the cam cylinder 5 rotates, the second group moving cylinder 10 also moves in the optical axis direction while rotating. Further, the focus cam ring 11 moves in the optical axis direction along the focus cam 11a by rotating by engaging with a cam follower (not shown) attached to the inner periphery of the second group moving cylinder 10. In addition, the sub cam cylinder 8 is held on the inner diameter of the guide cylinder 4 by engaging a cam follower (not shown) with the guide cylinder 4 and the cam cylinder 5, and the sub cam cylinder 8 rotates as the cam cylinder 5 rotates. Move forward and backward in the axial direction.

  A third group lens barrel 13 including a third group lens is held on the inner diameter of the sub cam cylinder 8 by a cam follower (not shown), and the sub cam cylinder 8 rotates and moves to the same amount as the sub cam cylinder 8 moves in the optical axis direction. Move straight by the amount. Further, the third group lens barrel 13 is provided with a sub-aperture unit 14b configured such that the aperture diameter is changed by the rectilinear movement of the third group lens barrel 13, and an integrally configured aperture unit 14a, and flexible printing is performed. It is connected to the control board 27 by a wiring board (not shown). Further, on the inner diameter of the sub cam cylinder 8, a fourth group moving cylinder 15 is held by a cam follower (not shown), and is engaged with a cam provided in the sub cam cylinder 8 and a rectilinear groove provided in the guide cylinder 4. It moves in the optical axis direction by an amount combined with the movement of the sub-cam cylinder 8. The fourth group moving cylinder 15 holds a fourth group connecting cylinder 16. Further, a fourth group barrel 17 including a fourth group lens is fixed to the fourth group connecting cylinder 16. The guide cylinder 4 further holds a focus unit base 30. The focus unit base 30 is configured as a main part of a focus drive unit including a vibration wave motor. Details of the focus drive unit will be described later.

  On the outer diameter side of the fixed cylinder 1, a zoom operation ring 24 is bayonet-coupled while being fitted to the fixed cylinder 1 so as to be rotatable at a fixed position. Further, the zoom key (not shown) integrally attached to the zoom operation ring 24 comes into contact with a contact portion that limits the rotation region of the fixed cylinder 1, so that the rotation region is limited. For this reason, the zoom operation ring 24 is configured to be rotatable only in a predetermined rotation region.

  Next, the configuration of the focus drive unit will be described in detail with reference to FIGS. In FIG. 1 to FIG. 3, a manual communication ring 31 is attached to the focus unit base 30 so as to come into contact with an intermediate end surface of the focus unit base 30. A slip ring 32 is in contact with the manual communication ring 31, and a roller 34 that is arranged in three equal parts in the radial direction with respect to the optical axis OA is in contact with the slip ring 32. Here, the surface roughness of each contact surface is set so that the frictional resistance between the manual communication ring 31 and the slip ring 32 is less than the frictional resistance between the slip ring 32 and the roller 34.

  Next, the roller 34 is rotatably held by a holding shaft disposed in a radial direction with respect to the optical axis OA on the roller carrying ring 33 (annular member), and further, a retaining washer 35 prevents the shaft 34 from being detached. Is done. A focus key 36 that engages with the focus cam ring 11 is fixed to the roller carrying ring 33. The focus key 36 restricts the rotation area of the roller carrying ring 33 by a rotation area restriction portion that abuts the focus unit base 30 in the rotation direction. In this embodiment, the roller carrying ring 33 (annular member) moves the focusing lens group in the optical axis direction by rotating around the optical axis OA (around the optical axis).

  Further, a brush member 37 corresponding to a flexible printed wiring board (not shown) attached to the focus unit base 30 and printed with a gray code pattern is attached to the roller carrying ring 33. A position encoder is configured. When the brush member 37 attached to the roller carrying ring 33 slides on the flexible printed wiring board, the rotational position of the roller carrying ring 33 is discriminated and can be used for controlling the focusing operation.

  A distance scale display member is provided on the outer peripheral side of the roller carrying ring 33. The distance scale display member has a distance scale indicating the in-focus position, and is attached to the roller carrying ring 33. In this embodiment, the distance scale display member includes a distance scale plate 47 (support member) made of an arc-shaped metal sheet metal, and a distance scale sheet 48 (sheet member) printed on the distance scale and attached to the distance scale plate 47. ). The distance scale plate 47 is attached with screws so that the distance scale sheet 48 printed according to the rotation angle is integrally attached and the rotation position can be adjusted.

As shown in FIG. 5, the zoom operation ring 24 of the present embodiment is provided with an insertion hole 24a and a through hole 24b as tool holes. The through-hole 24 b is a tool hole for fixing the distance scale plate 47 to the roller support ring 33 using screws after the adjustment of the position of the distance scale plate 47 with respect to the roller support ring 33 is completed . The insertion hole 24 a is a tool hole for inserting a pin (eccentric pin) used when adjusting the position of the roller carrying ring 33. The insertion hole 24a and the through hole 24b are provided on an optical infinite display on the distance scale sheet 48 integrally attached to the distance scale plate 47, and on the scale window 23 provided integrally with the fixed cylinder 1 (fixing member). The index line 23a (index) is provided at a position where it matches. The fixed cylinder 1 is also provided with tool holes (not shown , an insertion hole corresponding to the insertion hole 24a and a through hole corresponding to the through hole 24b) corresponding to these, and the optical sensitivity on the focal length is increased. These tool holes (insertion holes and through-holes of each member) are configured to coincide with each other at a rotational phase position of the focal length, for example, at a position closer to the telephoto end than an intermediate position of the focal length.

  In the lens barrel 100 of this embodiment, a coupling ring 38 abuts on the image surface side of the roller 34 that abuts on the slip ring 32, and includes a rotor 40, a stator 42, and a piezoelectric element 43 across a rubber sheet 39. A motor (vibration wave motor) is provided. This motor moves the second group barrel 12 (focusing lens group) in the optical axis direction. Reference numeral 41 denotes a dust-proof collar for fixing the rotational mounting position of the stator 42 and for preventing wear powder generated from the contact surfaces of the rotor 40 and the stator 42 from proceeding to the flexible printed wiring board side. Further, the felt sheet 44 and the spring washer 45 are in contact with each other while being biased by the thrust washer 46 in the optical axis direction.

  On the other hand, a focus operation ring 21 is arranged on the first group lens barrel 9 side of the focus unit base 30, and the focus operation ring 21 is fixed by engaging with a fixed position piece (not shown) fixed to the focus unit base 30. Perform position rotation. The focus operation ring 21 is engaged with the manual communication ring 31 in the rotation direction, and the manual communication ring 31 can be rotated by manually operating the focus operation ring 21. Further, the front ring 18 and the decorative ring 20 are fixed to the front end of the focus unit base 30 on the first group lens barrel 9 side with the reinforcing ring 19 interposed therebetween.

  Next, the configuration of the distance scale plate 47 will be described in detail with reference to FIGS. 3 and 4. As shown in FIGS. 3 and 4, the roller carrier ring 33 is provided with a guide portion 33a so as to have a rotational phase. Further, the distance scale plate 47 is provided with a guide engaging portion 47a configured to engage with the guide portion 33a and move around the optical axis and restrict movement in the optical axis direction. The guide portion 33a is configured to engage with the guide engagement portion 47a in a state where its position in the optical axis direction is restricted by the guide engagement portion 47a, and to rotate only a specific amount around the optical axis. A screw fastening portion 33 b for fixing the distance scale plate 47 with screws 49 is provided between the guide portions 33 a of the roller carrying ring 33. Thus, the distance scale plate 47 is configured to be position-adjustable around the optical axis with respect to the roller carrying ring 33 so as to be aligned with the index line 23a of the fixed cylinder 1.

  The distance scale plate 47 is fixed to the roller carrying ring 33 using screws 49 after the adjustment with respect to the position of the roller carrying ring 33 is completed. The rotational position of the distance scale plate 47 can be fixed by fastening the screw 49 to the screw fastening portion 33b. The distance scale plate 47 is provided with a tool groove 47b for engaging with a tool operated from the outside.

Next, a method for adjusting the distance scale plate 47 in the lens barrel will be described with reference to FIG. FIG. 5 shows a state during adjustment of the distance scale plate 47 of the lens barrel. When the distance scale is adjusted with respect to the index line 23a on the scale window 23, first, the rotation position of the zoom operation ring 24 is brought into contact with the long focal length end (telephoto end) having high optical sensitivity. In this state, the focus operation ring 21 is rotated using a tool such as a collimator, and the focus group is set to the optical infinite state. At this rotational phase position, the tool hole 24 b (through hole) provided in the zoom operation ring 24 and the tool hole (not shown , through hole ) provided in the fixed cylinder 1 are aligned, and the distance scale plate inside. It is possible to work on the screw 49 fixing the 47 and the adjustment hole 47a.

Subsequently, the screw 49 of the distance scale plate 47 fixed to the roller carrying ring 33 is loosened from the tool hole (through hole) through which the zoom operation ring 24 and the fixed cylinder 1 penetrate. Further, while maintaining the optical infinite state, the adjustment tool is inserted through the tool hole (insertion hole) penetrating the zoom operation ring 24 and the fixed cylinder 1, and the distance scale plate 47 is rotated around the optical axis to be integrally attached. The optical infinite position on the attached distance scale sheet 48 and the index line 23a on the scale window 23 are matched. After the alignment, the screws 49 are tightened again, and the distance scale plate 47 is fixed.

Next, the operation of the focus drive unit will be described. First, in the case of motor drive such as autofocus, the vibration wave motor is driven by a control command on the camera body side. The rotational force of the rotor 40, which is the output part of the vibration wave motor, causes the roller carrying ring that holds the roller 34 to roll while the roller 34 that is in contact with the connecting ring 38 that is disposed integrally with the rotor 40 is in contact. 33 is rotated in the forward direction with a reduction ratio of 1/2. A focus key 36 is fixed to the roller carrying ring 33, and the focus key 36 engages with a key engagement member 28 attached to the focus cam ring 11 to rotate and move the second group barrel 12 as a focus group. Further, the position of the operating region is detected by a position encoder constituted by the flexible wiring board and the brush member 37, and an excessive rotational force is not given for control.

  Next, a case where the focus operation ring 21 is operated for manual operation will be described. When the focus operation ring 21 rotates, the rotational force is transmitted to the engaged manual communication ring 31, and the rotational force is similarly transmitted to the slip ring 32 disposed integrally with the manual communication ring 31. . Since the slip ring 32 is in pressure contact with the roller 34 and a vibration wave motor is disposed in the direction of the mount side of the roller 34, the roller 34 rolls and holds the roller 34 when the slip ring 32 rotates. The roller carrying ring 33 also rotates forward with a reduction ratio of 1/2. When the roller carrying ring 33 is rotated, the second group barrel 12 as the focusing lens group is moved by the engagement of the focus key 36 as in the driving of the vibration wave motor.

  Next, a case where the roller carrying ring 33 hits the end of the rotation area and the focus operation ring 21 is rotated will be described. Since the slip ring 32 and the roller 34 have high frictional resistance, they do not slip between them, and slip occurs between the manual connection ring 31 and the slip ring 32 with less frictional resistance. By slipping between the roller 34 and the slip ring 32 that are in contact with each other, no abnormal noise is generated.

  Next, an operation when the photographer performs a zoom operation of the lens barrel 100 (when the zoom operation ring 24 is operated) will be described. When the zoom operation ring 24 is operated, the rotational force is transmitted to the cam cylinder 5 via a zoom key (not shown), and the cam cylinder 5 rotates at a fixed position with the outer diameter of the guide cylinder 4 connected to the bayonet. . Further, since the rectilinear cylinder 6 is held by the first group roller 7 on the outer diameter of the cam cylinder 5, and the first group lens barrel 9 including the first group lens is further held by the rectilinear cylinder 6, the first group barrel 9 Moves straight in the direction of the optical axis as the cam barrel 5 rotates.

  A second group moving cylinder 10 is held on the inner diameter of the guide cylinder 4 by a cam follower (not shown), and a focus cam ring 11 is held on the inner diameter of the second group moving cylinder 10 by a cam follower (not shown). Further, a second group barrel 12 including a second group lens is integrally held on the inner diameter of the focus cam ring 11. As the cam cylinder 5 rotates, the second group moving cylinder 10 also moves in the optical axis direction while rotating along a cam (not shown) provided in the guide cylinder 4. At this time, since the key engaging member 28 is engaged with the focus key 36, the second group lens barrel 12 held integrally with the focus cam ring 11 moves in the optical axis direction according to the amount of movement of the focus cam 11a. Go straight ahead.

  The sub cam cylinder 8 is held on the inner diameter of the guide cylinder 4 by engaging a cam follower (not shown) with the cam provided on the guide cylinder 4 and the cam provided on the cam cylinder 5. The sub cam cylinder 8 advances and retreats in the optical axis direction while rotating by the rotation. A third group lens barrel 13 including a third group lens is held on the inner diameter of the sub cam cylinder 8 by a cam follower (not shown) with respect to a cam provided on the guide cylinder 4 and a straight groove provided on the cam cylinder 5. When the sub cam cylinder 8 rotates, the sub cam cylinder 8 moves straight by the same amount as the movement amount of the sub cam cylinder 8 in the optical axis direction. The sub-aperture unit 14b, which is integrally fixed to the third group lens barrel 13 together with the aperture unit 14a, changes its aperture diameter by a straight movement of the third group lens barrel 13 by a cam provided on the guide cylinder 4, and generates unnecessary luminous flux. Cut.

  A fourth group moving cylinder 15 is held on the inner diameter of the sub cam cylinder 8 by a cam follower (not shown) and engaged with a cam provided on the sub cam cylinder 8 and a rectilinear groove provided on the guide cylinder 4. Then, it moves in the optical axis direction by an amount combined with the movement of the sub cam cylinder 8. The fourth group moving cylinder 15 holds a fourth group connecting cylinder 16, and the fourth group connecting cylinder 16 has a fourth group barrel 17 including a fourth group lens fixed thereto. By the rotation operation of the zoom operation ring 24, the first group barrel 9, the second group barrel 12, the third group barrel 13, and the fourth group barrel 17 move straightly while changing the distance from each other, and the focal length is increased. It is configured to be changeable.

  Next, the case where the photographer operates the focus operation ring 21 will be described again. The focus operation ring 21 has a structure that rotates at a fixed position with the outer diameter of the focus unit base 30, and the photographer can change the focus position by rotating the focus operation ring 21. The rotational force of the focus operation ring 21 acts to rotate the focus key 36 via the differential operation mechanism of the focus drive unit. The focus key 36 rotates and moves the second group lens barrel 12 (focusing lens group) integrally held by the focus cam ring 11 along the focus cam 11a via the key engaging member 28, and other lenses. The focus position can be adjusted by changing the interval for the group.

  Next, the operation of the lens barrel 100 when the photographer operates the camera body (imaging apparatus body) and operates the focus drive unit with autofocus based on drive information from the camera body will be described. The above-described vibration wave motor is provided inside the focus drive unit, and the vibration wave motor is driven by a signal that is arithmetically processed inside the lens barrel 100 based on a signal from the camera body. The rotational force of the vibration wave motor acts to rotate the focus key 36 via the differential operation mechanism. Then, by the same action as when the photographer rotates the focus operation ring 21, the second group barrel 12 (focusing lens group) moves forward and backward along the focus cam 11 a provided on the focus cam ring 11, Perform automatic focusing. Thus, the focusing lens group is configured to be movable in the optical axis direction by the vibration wave motor.

  In the present embodiment, the procedure for performing the adjustment again from the position temporarily fixed when adjusting the optical infinite index on the distance scale has been described. However, the present invention is not limited to this. For example, a method of storing the signal amount from the mechanical butting position to the optical infinite position using an encoder inside the focus driving unit may be adopted. In this case, there is also an effect that it is easy to reproduce the optical infinite position by electrically driving to the optical infinite position adjusted at the time of assembly. In the present embodiment, the position where the tool holes (through holes) for adjusting the optical infinite index of the fixed cylinder 1 and the zoom operation ring 24 are set as the long focal length end, but is not limited thereto. What is necessary is just to comprise so that a tool hole may align, for example, when a zoom lens is located in a predetermined rotation phase position in the telephoto end side rather than the intermediate position of a focal distance.

  According to the present embodiment, it is possible to provide a lens barrel capable of aligning the distance scale of the annular member and the position of the index of the fixed member. Therefore, the index position can be adjusted with respect to the optical infinite position from the almost completed state of the lens barrel, and the actual scale display position can be matched with the optical infinite position.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 ... Fixed cylinder 12 ... 2 group lens barrel 23a ... Index line 33 ... Roller support ring 47 ... Distance scale plate

Claims (5)

A focusing lens group;
An annular member for moving the focusing lens group in the optical axis direction by rotating around the optical axis;
A distance scale indicating a focus position, and a distance scale display member attached to the annular member;
A fixing member having an index indicating the position of the distance scale,
A convex guide portion is provided on the surface of the annular member on which the distance scale display member is attached,
The distance scale display member is provided with a hole-shaped guide engaging portion that engages with the guide portion and is movable around the optical axis and restricts movement in the optical axis direction.
The position of the distance scale display member is adjusted around the optical axis with respect to the annular member so as to align with the index of the fixed member, and the adjustment of the position relative to the annular member is completed. Thereafter, the lens barrel is fixed to the annular member using a screw through the guide engaging portion.   The fixing member includes an insertion hole for inserting a pin used when adjusting the position of the distance scale display member, and a through hole for fixing the distance scale display member to the annular member using the screw. The lens barrel according to claim 1, further comprising a hole. The lens barrel is a zoom lens;
The insertion hole and the through hole are arranged so that the position of the distance scale display member can be adjusted when the zoom lens is positioned on the telephoto end side with respect to the intermediate position of the focal length. The lens barrel according to claim 2. The distance scale display member is configured to include a support member made of an arc-shaped metal sheet metal, and a sheet member printed on the distance scale and attached to the support member. Item 4. The lens barrel according to any one of Items 1 to 3. An imaging device body;
A camera system comprising: the lens barrel according to claim 1, wherein the lens barrel is replaceably attached to the imaging apparatus main body.