JP2008139802A - Lens mirror frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens mirror frame which has intersecting cam grooves, the lens mirror frame providing smooth advancing or retracting drive without causing separation in the intersecting portion of the cam grooves. <P>SOLUTION: The lens mirror frame includes: a cam frame 4 having the two intersecting bottomed cam grooves 4d and 4e of different depths, and projections 4g formed on the bottom of the intersecting portion P1 of the shallow cam groove 4e; a fourth group frame that has at its leading end a slit through which the projections 4g can be passed, also has a cam follower 9a engaged with the cam groove 4e and passed through the intersecting portion P1, and moves relative to the cam frame 4; and a second group frame that has a cam follower 7a engaged with the deep cam groove 4d, and moves relative to the cam frame 4. Both cam followers 9a and 7a can be passed through the intersecting portion P1 without separating from the cam groove 4e or 4d. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure of a lens barrel that is driven back and forth along a cam groove.

  In a lens barrel that can be advanced and retracted and applied to a conventional camera or the like, normally, each of the lens frames is moved in the optical axis direction by engagement of cam grooves and cam followers (usually three pairs) provided in each barrel. A structure that relatively moves forward and backward is adopted. In such a lens barrel, the cam grooves may be crossed in order to cope with a reduction in the size of the lens barrel and an increase in the amount of advancement / retraction. At that time, it is necessary to adopt a structure in which the cam follower does not come off from the corresponding cam groove at the intersection of the cam grooves.

  The lens barrel cam mechanism disclosed in Patent Document 1 is composed of a single set of a single cam groove and a cam follower, and front and rear cam grooves and cam followers that have different positions in the axial direction. The cam mechanism is provided with at least one pair of front and rear groups, and the single set of cam grooves and the cam grooves of the front and rear groups intersect to satisfy at least one of the two conditions.

One of the above conditions is that the groove width of the cam groove of a single set is wider than the groove width of the cam groove of the pair of front and rear pairs, and the other is that The circumferential interval between one cam groove of the group and the circumferential interval between the cam groove of the single set and the other cam groove of the front and rear pair group are made different. In this conventional cam mechanism, even if there are intersecting portions in the cam groove, the cam follower engaged with them does not drop off.
JP 2005-227651 A

  However, according to the lens barrel cam mechanism disclosed in Patent Document 1 described above, it is necessary to provide a pair of cam grooves for a single cam groove, and the arrangement space is large. The length in the optical axis direction becomes longer. Or the cam groove becomes complicated, and the layout in the rotational direction is difficult, so that there is a limit to the compactness of the lens frame.

  The present invention has been made in order to solve the above-described problem, and a lens barrel having cam grooves that intersect each other can be smoothly advanced and retracted without falling off at the intersection. The purpose is to propose a mirror frame.

  In the lens barrel according to claim 1 of the present invention, the bottomed grooves intersect with each other, the first frame member having a protrusion on the bottom of the intersection or in the vicinity thereof, and the protrusion passes through the tip. The first frame member having a groove shape that has a possible slit shape, engages with one of the bottomed grooves, slides in the bottomed groove, and passes through the intersecting portion. And a second frame member that moves relative to the second frame member.

  The lens barrel according to claim 2 of the present invention is the lens barrel according to claim 1, wherein the protrusion has a protruding height lower than the depth of the bottomed groove.

  The lens barrel according to claim 3 of the present invention is the lens barrel according to claim 1, wherein the protrusion protrudes in a long plate shape in a direction along one cam line of the bottomed groove. The protruding height is lower than the depth dimension of the bottomed groove.

  The lens barrel according to claim 4 of the present invention has a first groove and a second groove intersecting the first groove, and a protrusion is formed on the bottom of the intersecting part or the vicinity thereof. A first frame member having a projecting first groove follower having a slit shape that engages with the first groove and allows the projecting portion to pass therethrough; A groove follower is capable of passing through the intersecting portion, engages with the second groove, the second frame member moving relative to the first frame member, and the height is the first groove. A third groove follower having a projecting second groove lower than the projecting height of the follower, the second groove follower being capable of passing through the intersecting portion and moving relative to the first frame member; Frame member.

  The lens barrel according to claim 5 of the present invention is the lens barrel according to claim 4, wherein the protrusion at the intersecting portion has a height at which the protruding height does not interfere with the second groove follower. .

  A lens barrel according to a sixth aspect of the present invention is the lens barrel according to the fourth aspect, wherein the first groove is thinner than the second groove.

  The lens barrel according to claim 7 of the present invention has a first groove and a second groove intersecting with the first groove, and a protrusion on the intersecting portion or the bottom surface in the vicinity thereof. A first frame member having a first groove follower that engages with the first groove, and a slit shape that allows the protrusion to pass through is provided at a tip of the first groove follower, A second frame member capable of passing through the intersection and moving relative to the first frame member; and a second groove follower engaged with the second groove; A slit shape that allows the projection to pass through is provided at the tip of the groove follower, and has a third frame member that can pass through the intersection and moves relative to the first frame member.

  A lens barrel according to an eighth aspect of the present invention includes a first groove and a second groove that is deeper than the first groove and intersects the first groove. A first frame member having a protrusion on the crossing portion of the groove, or a bottom surface in the vicinity thereof, and a slit shape that engages with the first groove and allows the protrusion to pass through the tip. A second frame member that has a protruding first groove follower, the first groove follower is capable of passing through the intersecting portion, and moves relative to the first frame member; A second groove follower engaged with the second groove and having a height greater than the depth of the first groove, the second groove follower being capable of passing through the intersecting portion, And a third frame member that moves relative to the frame member.

  According to the present invention, it is possible to provide a lens barrel that can be smoothly advanced and retracted without falling off at the intersection of the cam grooves.

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

  1 to 3 are cross-sectional views in each state including the optical axis of the lens barrel incorporating the lens barrel of the first embodiment of the present invention, in which FIG. 1 is in a retracted state and FIG. 2 is in a wide state. FIG. 3 shows the tele state. FIG. 4 is an exploded perspective view of a cam frame, a float ring, a second group frame, and a fourth group frame as the lens barrel constituting the lens barrel. FIGS. 5 and 6 are development views showing cam grooves (showing a pair of three pairs) on the inner peripheral surface of the cam frame, cam followers engaged with the cam grooves, and an engaged state. FIG. 7 is a cross-sectional view taken along the line AA of FIG. FIG. 8 is a perspective view around the intersection of the cam follower and the cam groove. 9 is a cross-sectional view taken along line BB in FIG.

  In the following description, the optical axis of the photographic lens is O, the subject side in the optical axis O direction is the front (feeding side), and the imaging plane side (retracting side) is the rear. The rotation direction of each frame member is indicated by the rotation direction viewed from the subject side.

  The lens barrel 1 of this embodiment is a retractable zoomable lens barrel, and is supported by the fixed frame 2 and the fixed frame 2 as shown in FIGS. The cam frame 4 that is the first frame member to be driven, the moving frame 3 that moves forward and backward with the cam frame 4 in the optical axis O direction, the float ring 5 that moves forward and backward with the cam frame 4, and the cam frame 4 in the optical axis O direction. The first group frame 6 that is driven back and forth, the openable / closable lens barrier 14 that is housed in the front surface of the first group frame 6, and the cam frame 4 that is driven forward and backward in the optical axis O direction while being restricted by the float ring 5. A second group frame 7 serving as a third frame member and a fourth group frame 9 serving as a second frame member; and a third group frame 8 which is driven to focus in the direction of the optical axis O by a focus drive unit while being restricted by the fixed frame 2; , Integrally coupled to the rear end side of the fixed frame 2 A CCD unit which is held in the lifting plate 21 and the plate, and a zoom driving section not focus drive and illustrated. The lens barrel 1 is held by a first group frame 6, a second group frame 7, a third group frame 8, and a fourth group frame 9 as photographing lens groups, and is sequentially arranged along the optical axis O from the front side. The first group lens 15, the second group lens 16, the third group lens 17, and the fourth group lens 18 are provided.

  The fixed frame 2 is a cylindrical member that is fixed to a photographing device such as a camera body, and is provided with a cam groove 2b and a rectilinear groove 2a on the inner peripheral portion.

  The moving frame 3 is a cylindrical member that is slidably fitted into the inner peripheral portion of the fixed frame 2, a convex portion that is slidably fitted into the rectilinear groove 2 a of the fixed frame 2, and a portion of the cam frame 4. The circumferential groove 4h has a circumferential convex portion that is connected to the bayonet. Accordingly, the moving frame 3 moves forward and backward in the optical axis O direction together with the cam frame 4 without rotating the moving frame itself as the cam frame 4 rotates and retreats.

  The cam frame 4 is a cylindrical member that is inserted into the fixed frame 2 and is rotatable and retractable, and a gear portion 4a that meshes with a zoom driving long gear (not shown) on the fixed frame 2 side on the outer peripheral rear portion. A cam follower 4b that is slidably engaged with the cam groove 2b of the fixed frame 2 is provided. In addition, the three outer peripheral frame cam grooves 4c are inclined with respect to the optical axis O direction, and the inner peripheral portion is inclined with respect to the optical axis O direction and includes three pairs (six) intersecting each other. A cam groove for a second group frame 4d as a second cam groove and a fourth group frame cam groove 4e as a first cam groove are provided. The second group frame cam groove 4d and the fourth group frame cam groove 4e are provided with cam follower insertion grooves at the time of assembling, and grooves 4d1 and 4e1 which are opened to the rear side are connected (FIG. 4). , 5). The detailed shapes and functions of the cam grooves 4d and 4e and the cam followers 7a and 9a of the second group and the fourth group that engage with the cam grooves will be described later.

  The cam frame 4 is rotationally driven through the long gear by a motor (not shown) of a zoom drive unit, and is rotated with respect to the fixed frame 2 while rotating from the retracted position to the wide position where the image can be taken and the tele position by the cam groove 2b. Are fed out in the direction of the optical axis O.

  The float ring 5 is a cylindrical member that is fitted into the inner peripheral portion of the cam frame 4. The guide protrusion 5 a that fits the rectilinear groove 2 a of the fixed frame 2 at the outer peripheral portion, and the second group frame rectilinear advance at the inner peripheral portion. Guide grooves 5b and fourth group frame rectilinear guide grooves 5c are provided.

  The float ring 5 is fitted in the inner peripheral portion of the cam frame 4 so as to be relatively rotatable with the cam frame 4 being sandwiched in the optical axis O direction. Accordingly, the float ring 5 is driven to move back and forth in the optical axis O direction together with the cam frame 4 as the cam frame 4 rotates and retreats in a rotation restricted state guided by the rectilinear groove 2 a of the fixed frame 2.

  The first group frame 6 is a cylindrical frame member that is fitted into the inner peripheral portion of the moving frame 3, a guide projection 6 b that is slidably fitted into the rectilinear groove 3 b of the moving frame 3 at the outer peripheral rear end portion, and a cam at the inner peripheral rear end portion. Three cam followers 6a that engage with the cam groove 4c for the first group frame of the frame 4 are provided. A first lens group 15 is held in the front opening of the first group frame 6. In addition, a decorative plate is fixed to the front surface portion of the first group frame 6, and a lens barrier 14 that opens and closes the front surface of the first lens group 15 is disposed between the decorative plate and the decorative plate.

  The group frame 6 is driven to advance and retreat in the optical axis O direction with respect to the cam frame 4 and the moving frame 3 as the cam frame 4 rotates and retreats in a state where the rotation is restricted by the rectilinear groove 3 b of the moving frame 3. .

  The second group frame 7 is a cylindrical frame member that is fitted into the inner peripheral portion of the cam frame 4, and three linear guide protrusions that are slidably fitted into the guide grooves 5 b of the float ring 5 at positions in the outer peripheral portion 3 direction. A portion 7b and three cam followers 7a serving as projecting second groove followers disposed on the convex portion 7b and engaging with the cam groove 4d of the cam frame 4 are provided (FIG. 4). A second group lens 16 is held in the central opening of the second group frame 7. Further, a shutter frame 10 including a shutter drive unit and shutter blades is supported on the front side of the second group frame 7 in a state of being urged forward by an urging spring 11.

  The second group frame 7 moves forward and backward in the optical axis O direction with respect to the cam frame 4 by the cam groove 4 d as the cam frame 4 rotates in a state in which the rotation is restricted by the guide groove 5 b of the float ring 5.

  The focus drive unit is housed in a focus drive unit main body 32 that is fixed to the outside of the fixed frame 2, and includes a focusing motor 33, a feed screw shaft 36 that is rotationally driven by the motor 33 via a gear train, and a guide shaft. 34 and a focus drive member 35 that is supported by the guide shaft 34 and is driven in the direction of the optical axis O by the feed screw 36 to drive the third group frame 8 forward and backward.

  The third group frame 8 is a frame member that is supported in a state in which the guide protrusion 8a is fitted in the rectilinear groove 2a inside the fixed frame 2, and a third group lens 17 that is a focus lens is provided at the center opening. Is retained. The third group frame 8 is driven back and forth in the direction of the optical axis O by the focusing motor 33 via the feed screw shaft 36 and the focus drive member 35 during the retracting drive and the focus drive.

  The fourth group frame 9 is a cylindrical frame member that is fitted into the inner periphery and the rear part of the cam frame 4. Three convex guide portions 9b extending along the direction of the optical axis O, which are slidably fitted into the guide grooves 5c of the float ring 5 at positions in the outer peripheral portion 3 direction, and the convex portions Three cam followers 9a as projecting first groove followers that engage with the cam grooves 4e of the cam frame 4 are provided on 9b. A fourth group lens 18 is held in the central opening of the fourth group frame 9.

  The fourth group frame 9 moves forward and backward in the optical axis O direction with respect to the cam frame 4 by the cam groove 4 e as the cam frame 4 rotates in a state where the rotation is restricted by the guide groove 5 c of the float ring 5.

  The holding plate 21 is fixed to the rear end surface of the fixed frame 2 in a state where the optical low-pass filter 22 and the image sensor 24 with the protective glass 23 are supported.

  On the imaging surface of the image sensor 24, subject light that has passed through each of the lens groups 15 to 18 is imaged at the time of shooting, and an imaging electric signal of the subject image is output from the image sensor 24.

  When the lens barrel 1 of the present embodiment having the above-described configuration is in the retracted state, the moving frame 3, the cam frame 4, the float ring 5, the group frame 6, and the cam frame 4 are fixed as shown in FIG. It is retracted to the retracted position inside the frame 2. Further, the second group frame 7, the third group frame 8, and the fourth group frame 9 are also accommodated in the retracted position inside the cam frame 4. The lens barrier 14 is in a closed position that covers the front surface of the first lens group 15.

  When the cam frame 4 is rotated clockwise by a predetermined angle (+ θ direction) in order to make the lens barrel 1 in a wide state capable of photographing, the cam frame 4 and the moving frame 3 are moved to the wide position as shown in FIG. It is drawn out. Further, the group frame 6 is extended to the wide position by the rotation and forward / backward movement of the cam frame 4. Further, the second group frame 7 and the fourth group frame 9 move relative to the cam frame 4 in their respective wide positions. The third group frame 8 is driven to the focusing position by the focusing motor 33.

  When the cam frame 4 is further rotated clockwise (+ θ direction) to bring the lens barrel 1 into the tele state, the cam frame 4 is slightly extended to the tele position together with the moving frame 3 as shown in FIG. The first group frame 6 is retracted to the tele position by the rotation and forward / backward movement of the cam frame 4. The second group frame 7 is extended to the front tele position with respect to the cam frame 4, and the fourth group frame 9 is extended to the rear tele position with respect to the cam frame 4. The third group frame 8 is driven to the focusing position by the focusing motor 33.

  Here, the cam grooves 4d and 4e disposed on the inner peripheral surface of the cam frame 4 and the arrangement and shape of the cam followers 7a and 9a disposed on the outer peripheral surfaces of the second group frame 7 and the fourth group frame 9, and further, Details of the moving operation will be described with reference to the developed view of the cam groove in FIGS. 5 and 6, the sectional view in FIG. 7, the perspective view of the cam groove and the cam follower in FIG. 8, and the sectional view in FIG.

  The cam grooves 4d and 4e and the cam followers 7a and 9a as a pair are arranged in the cam frame 4, or the second group frame 7 and the fourth group frame 9 in the same phase shift state. The pair will be described.

  In addition, the cam frame rotation position (angle) θ1− or θ2− on the development view of FIG. 5 (similarly to the development views of FIGS. 6, 10, and 14) The cam follower 7a of the second group frame 7 or the cam follower 9a of the fourth group frame 9 shows the relative movement position (angle) on the inner peripheral surface of the cam frame 4 when rotating to the position. Then, the clockwise rotation angle of the cam frame 4 is 2, the relative rotation angle + θ of the fourth group frame (in FIG. 5, the cam follower is relatively moved leftward), and the counterclockwise rotation angle is the second, relative rotation of the fourth group frame. It will be described as an angle −θ (in FIG. 5, the cam follower is relatively moved in the right direction).

  The cam groove 4d for the second group frame and the cam groove 4e for the fourth group frame of the cam frame 4 are both bottomed grooves having a trapezoidal cross section and intersect each other at two points. That is, as shown in FIG. 5, from the intersection P0 between the retracted rotation position θ1C of the cam groove 4d to the wide rotation position θ1W and the cam follower insertion portion 4e1 on the cam groove 4e side, and from the wide rotation position θ1W of the cam groove 4d. The region between the tele rotation position θ1T and the region between the retracted rotation position θ2C and the wide rotation position θ2W of the cam groove 4e intersect at two points of an intersection P1 (intersection rotation angle phase difference θP).

  Note that the cam stripe (the center line of the cam groove width) S2 of the cam groove 4e in the vicinity of the intersection P1 is a straight line. However, the cam line S1 of the cam groove 4d at the intersection P1 is not necessarily a straight line.

  The groove width d2 of the cam groove 4e is wider than the groove width d1 of the cam groove 4d. In other words, the root diameter (actual dimension width d4 in the cam stripe S2 direction) of the cam follower 9a that engages with the cam groove 4e is set larger than the groove width d1 of the cam groove 4d.

  Further, the depth h1 of the groove from the cam frame inner peripheral surface 4f to the bottom surface 4d2 of the cam groove 4d is deeper than the depth h2 of the groove to the bottom surface 4e2 of the cam groove 4e (FIG. 9). A pair of protrusions 4g having the same height as the groove depth h2 are provided in the cam groove 4e in the state separated by the cam groove 4d at the entrance and exit near the intersection P1.

  The two protrusions 4g are arranged along the cam line S2 of the cam groove 4e. Further, an inner inclined surface 4g1 on the cam bar S1 side of the protrusion 4g is arranged along the groove surface of the cam groove 4d in a state of facing the intersection P1.

  On the other hand, the cam follower 7a of the second group frame 7 is a truncated cone-shaped cam follower (a shape obtained by cutting the apex of the cone) and engages with the cam groove 4d without play (with a small fitting gap). The insertion length h3 in the cam groove depth direction is longer than the groove depth h2 of the cam groove 4e and is substantially equal to the groove depth h1 of the cam groove 4d.

  The cam follower 9a of the fourth group frame 9 is a frustoconical cam follower having a slit portion 9a1 at the center tip (however, a shape obtained by cutting the apex of the cone), and has no play on the cam groove 4e side (the fitting gap is not present). Engage (with or without). The insertion length h4 in the cam groove depth direction is shallower than the groove depth h2 of the cam groove 4e. The width d3 of the slit portion 9a1 is a width that fits into the protrusion 4g without looseness (with a small fitting gap). Further, the inclination direction of the slit portion 9a1 with respect to the optical axis O coincides with the direction of the cam line S2.

  Assembly and sliding operation of the cam followers 7a and 9a with respect to the cam grooves 4d and 4e having the above-described configuration will be described.

  At the time of assembly, the cam follower 9a needs to pass through the intersection P0 on the cam follower insertion portion 4e1 of the cam groove 4e, but it may be inserted with care only at the time of assembly.

  During the extension operation outside the imaging region of the lens barrel (between the retracted state and the wide state), one cam follower 9a causes the intersection P1 of the cam groove 4e between the retracted rotation position θ2C and the wide rotation position θ2W by the rotation of the cam frame 4. pass. When the cam follower 9a is within the above-mentioned intersection range with the cam groove 4d (the state shown in FIG. 6), the actual dimension width d4 of the cam follower 9a is wider than the groove width d1 of the cam groove 4d, and before and after the intersection P1. The slit portion 9a1 is engaged with the protrusion 4g of the cam groove 4e. Accordingly, the cam follower 9a smoothly slides without dropping from the cam groove 4e. The state during the movement is shown in the sectional view of FIG.

  When the cam follower 9a passes over the protrusion 4g on the intersection P1, slight engagement backlash due to variation in shape, etc., if any occurs, the area is located at the collapsible rotation position θ2C outside the imaging area and wide. Since the rotation position is between θ2W, the rattling does not affect the photographing.

  The other cam follower 7a is located at the intersection P0 when the cam groove 4d is extended outside the imaging area (between the retracted rotation position θ1C and the wide rotation position θ1W), and further within the imaging area (between the wide rotation position θ1W and the tele rotation position θ1T). It is necessary to pass through the intersection P1 during the zooming operation. However, when passing through the intersections P0 and P1, the tip of the cam follower 7a is always engaged with a portion deeper than the cam groove 4e of the cam groove 4d. Move smoothly.

  According to the lens barrel of the present embodiment described above, the cam frame is arranged with a plurality of cam grooves intersecting to reduce the diameter and length of the cam frame, and the lens barrel is in a shooting state or a retracted state. It is possible to achieve downsizing in And even if it employs a cam frame with intersecting cam grooves as described above, the cam follower does not fall off and the advance / retreat frame member can be driven smoothly.

  However, when it is necessary to place the intersection P1 in the imaging region, that is, between the wide rotation position θ2W and the tele rotation position θ2T, the cam follower 9a gives a smoother movement when passing the intersection P1. Assume that the above-described slight engagement backlash is given in terms of dimensions. As a modified example of the cam groove for suppressing the influence of the wobbling of the fourth group frame 9 due to the rattling, the phases of the three cam grooves 4e are shifted with respect to the three cam grooves 4d arranged in the cam frame 4, respectively. Can propose

  In this modification, the rotational angle phase difference ΔθC between the retracted rotation positions θ1C and θ2C of the cam frame 4 shown in FIG. 5 in the cam grooves 4d and 4e is changed between the three pairs of cam grooves. Further, the rotational positions of the three cam followers 9a of the fourth group frame 9 are also shifted in correspondence with the cam grooves.

  In this modification, between the wide rotation position θ2W and the tele rotation position θ2T of the cam frame 4, at least two cam followers 9a out of the three pairs are engaged positions outside the intersection P1 with respect to the respective cam grooves 4e. It is in. Therefore, the three cam followers 9a do not pass through the intersection P1 of the cam groove 4e at the same time, thereby suppressing the wobbling of the fourth group frame 9 due to the rattling of the fourth group frame 9 at each intersection P1 and suppressing the influence on the photographing. be able to.

  Next, a lens barrel that incorporates the lens barrel of the second embodiment of the present invention will be described with reference to FIGS.

  FIG. 10 is a development view showing a cam groove (showing a pair of three pairs) on the inner peripheral surface of the cam frame in the lens barrel of the present embodiment, a cam follower engaged with the cam groove, and an engaged state. 11 is a cross-sectional view taken along the line CC of FIG. FIG. 12 is a perspective view around the intersection of the cam follower and the cam groove. 13 is a cross-sectional view taken along the line DD of FIG.

  The lens barrel of the present embodiment includes a cam groove for a second group frame, a cam groove for a fourth group frame, and a cam follower that engages with the cam grooves with respect to the lens barrel of the first embodiment. The other shapes are the same as those of the first embodiment. Only the different parts will be described below.

  The cam barrel 4A of the lens barrel of the present embodiment has a second cam paired with three pairs (six cam grooves) which are inclined with respect to the optical axis O direction on the inner peripheral portion and intersect each other. A second group frame cam groove 4Ad as a groove and a fourth group frame cam groove 4Ae as a first cam groove are provided. The second group frame cam groove 4Ad and the fourth group frame cam groove 4Ae are provided with groove portions 4Ad1, 4Ae1 for connecting cam followers during assembly (FIG. 10). However, the groove 4Ad1 side is a groove that opens to the rear side of the cam frame 4, and the groove 4Ae1 is a groove that opens to the front side.

  The second group frame 7A is provided with three cam followers 7Aa as second groove followers that engage with the cam grooves 4Ad. The fourth group frame 9A (not shown) is provided with three cam followers 9Aa as first groove followers that engage with the cam grooves 4Ae.

  The cam grooves 4Ad and 4Ae of the cam frame 4A are both bottomed grooves having a trapezoidal cross section. The cam groove 4Ad is rotated from the wide rotation position θ1W of the cam groove 4Ad to the tele rotation position θ1T and from the retracted rotation position θ2C of the cam groove 4Ae. The vehicle intersects at the intersection P11 (intersection rotation angle phase difference θP) up to the position θ2W.

  It should be noted that the cam streak (center line of the cam groove width) S12 of the cam groove 4Ae and the cam streak S11 of the cam groove 4Ad in the vicinity of the intersection P11 are straight lines. Further, it is desirable that the cam groove 4Ae is equal in width to the cam groove 4Ad. The groove depths h8 from the cam frame inner peripheral surface 4Af to the bottom surfaces 4Ad2 and 4Ae2 of the cam grooves 4Ad and 4Ae are equal to each other (FIG. 13).

  A cylindrical protrusion 4Ag having a protruding height equal to the groove depth h8 is provided at the center position of the groove bottom of the intersection P11 (intersection of the cam bars S11 and S12) (FIG. 13).

  On the other hand, the cam follower 7Aa of the second group frame 7A is formed of a truncated cone-shaped cam follower (cut at the apex) having a slit portion 7Aa1 at the center tip, and has no play in the cam groove 4Ad (with a small fitting gap). ) Engage. The cam follower height is substantially equal to or slightly shorter than the groove depth h8 of the cam grooves 4Ad, 4Ae. The groove width of the slit portion 7Aa1 is a groove width that engages the protrusion 4Ag with no play (with a small fitting gap). The inclination direction of the groove of the slit portion 7Aa1 with respect to the optical axis O coincides with the direction of the cam line S11.

  Similarly, the cam follower 9Aa of the fourth group frame 9A is also formed of a truncated cone-shaped cam follower having a slit 9Aa1 at the center tip, and engages with the cam groove 4Ae (with a small fitting gap). The cam follower height is substantially equal to or slightly shorter than the groove depth h8 of the cam grooves 4Ad, 4Ae. The groove width of the slit portion 9Aa1 is a groove width that engages with the protrusion 4Ag without play (with a small fitting gap). The inclination direction of the groove of the slit portion 9Aa1 with respect to the optical axis O coincides with the direction of the cam bar S12.

  Next, the sliding operation of the cam followers 7Aa and 9Aa with respect to the cam grooves 4Ad and 4Ae in the present embodiment having the above-described configuration will be described.

  When the lens barrel is extended from the retracted state to the wide state, one cam follower 9Aa passes through the intersection P11 of the cam groove 4Ae between the retracted rotation position θ2C and the wide rotation position θ2W by the rotation of the cam frame 4A. When the cam follower 9Aa is within the cam groove crossing range (the state shown in FIG. 12), the slit portion 9Aa1 of the cam follower 9Aa is engaged with the protrusion 4Ag. When the engagement of the slit portion 9Aa1 with the protrusion 4Ag is released, the outer diameter of the cam follower 9Aa engages with the cam groove 4Ae on the front side in the movement direction. Therefore, the cam follower 9Aa smoothly passes through the intersection P11 without dropping from the cam groove 4Ae.

  The situation at this time will be described with reference to FIG. FIG. 11 is a cross-sectional view taken along the line CC in FIG. 10 and is a cross-sectional view of the protrusion 4Ag, the cam follower 9Aa, and the cam groove 4Ae taken along the cam line S12. The cam follower 9Aa advances in the cam groove 4Ae and starts to pass through the intersection P11, or immediately before completion of the passage, as shown by 9Aa 'in the figure, the inner wall of the slit portion 9Aa1 of the cam follower 9Aa is formed between the protrusion 4Ag and the cam groove. It is in contact with both of the 4Ae slopes and smoothly crosses the cam groove 4Ad.

  The other cam follower 7Aa passes through the intersection P11 between the wide rotation position θ1WC and the tele rotation position θ1T of the cam groove 4Ad when extended from the wide state to the tele state. Also in this case, the slit portion 7Aa1 of the cam follower 7Aa is engaged with the protrusion 4Ag when the cam follower 9Aa is within the cam groove crossing range as in the case of the cam follower 9Aa. When the engagement of the slit portion 7Aa1 with the protrusion 4Ag is released, the outer diameter of the cam follower 7Aa engages with the cam groove 4Ad. Therefore, the cam follower 7Aa smoothly passes through the intersection P11 without dropping from the cam groove 4Ad.

  According to the lens barrel of the present embodiment described above, the same effects as in the case of the first embodiment can be obtained. In particular, in the case of the present embodiment, the shape of the cam groove is simple and the cam groove can be easily arranged. It is. Since the protrusion 4Ag has a cylindrical shape (circular cross section), the slidability of the slit portion of the cam follower is good, and the intersection of the cam follower is smoothly performed.

  In the present embodiment, the cam follower 7Aa passes through the intersection P11 between the wide rotation position θ1WC and the tele rotation position θ1T that are the imaging range area. At this time, in order to give a smoother motion, if the cam follower 7Aa is slightly rattled by switching the engagement state when passing through the intersection, there is a possibility that the second group frame 7A may be staggered.

  Accordingly, in order to suppress the wobbling of the second group frame 7A, the camshaft 4Ad and 4Ae are retracted by the cam frame 4A as shown in FIG. 10 in the same manner as the cam groove modification of the first embodiment described above. The rotational angle phase difference ΔθC between the positions θ1C and θ2C is changed between the three pairs of cam grooves, and the positions in the rotational direction of the three cam followers 9Aa of the fourth group frame 9A are also shifted correspondingly.

  Due to the displacement of the cam groove arrangement position, the rotational position of each intersection P11 between the three pairs of cam grooves is displaced, and the same effect as the modification of the cam groove of the first embodiment described above can be obtained.

  Next, a lens barrel incorporating the lens barrel of the third embodiment of the present invention will be described with reference to FIGS.

  FIG. 14 is a development view showing a cam groove (showing a pair of three pairs) on the inner peripheral surface of the cam frame, a cam follower engaged with the cam groove, and an engaged state in the lens barrel of the present embodiment. FIG. 15 is a perspective view around the intersection of the cam follower and the cam groove. 16 is a cross-sectional view taken along line EE in FIG.

  The lens barrel of the present embodiment includes a cam groove for a second group frame, a cam groove for a fourth group frame, and a cam follower that engages with the cam grooves with respect to the lens barrel of the first embodiment. The other shapes are the same as those of the first embodiment. Only the different parts will be described below.

  The cam barrel 4B of the lens barrel of the present embodiment has a second cam paired with three pairs (six cam grooves) which are inclined with respect to the optical axis O direction on the inner peripheral portion and intersect each other. A second group frame cam groove 4Bd as a groove and a fourth group frame cam groove 4Be as a first cam groove are provided. The cam groove 4Bd1 and 4Be1 for inserting cam followers at the time of assembly are connected to the cam groove 4Bd for the second group frame and the cam groove 4Be for the fourth group frame (FIG. 14). The groove portions 4Bd1 and 4Be1 are both grooves opened to the rear end side of the cam frame 4B.

  The second group frame 7B is provided with three cam followers 7Ba as second groove followers that engage with the cam grooves 4Bd. The fourth group frame 9B is provided with three cam followers 9Ba as first groove followers that engage with the cam grooves 4Be.

  Cam grooves 4Bd and 4Be of the cam frame 4B are bottomed grooves each having a trapezoidal cross section, and intersect each other at two locations. That is, as shown in FIG. 14, from the retracted rotation position θ1C of the cam groove 4Bd to the wide rotation position θ1W and the intersection P20 between the cam follower insertion portion 4Be1 of the cam groove 4Be and the wide rotation position θ1W of the cam groove 4Bd. It intersects at two points of the intersection P21 (intersection rotation position θP) between the rotation position θ1T and the retracted rotation position θ2C of the cam groove 4Be to the wide rotation position θ2W.

  Note that the cam stripe (the center line of the cam groove width) S22 of the cam groove 4Be in the vicinity of the intersection P21 is a straight line, but the cam stripe S21 of the cam groove 4Bd is not necessarily a straight line. Further, the groove width d8 of the cam groove 4Be is narrower than the groove width d7 of the cam groove 4Bd. The groove depths h5 from the cam frame inner peripheral surface 4Bf to the bottom surfaces 4Bd2 and 4Be2 of the cam grooves 4Bd and 4Be are equal to each other (FIG. 16).

  A straight plate-like protrusion 4Bg along the cam line S22 is provided on the bottom surface of the groove at the intersection P21. The length d9 of the protrusion 4Bg in the cam stripe direction is preferably longer than the groove width d7 of the cam groove 4Bd. However, even if the length d9 is shorter than the groove width d7, the length of the cam follower 9Ba does not come off from the cam groove 4Be on the intersection P21. It only has to have. The height h6 of the protrusion 4Bg to the apex 4Bg1 is a protrusion height lower than the groove depth h5.

  On the other hand, the cam follower 7Ba of the second group frame 7B is formed of a truncated cone-shaped (following the apex portion) cam follower and engages with the cam groove 4Bd without play (with a small fitting gap). The cam follower height h7 does not reach the depth h5 of the cam grooves 4Bd and 4Be, and does not interfere with the protrusion 4Bg (not in contact with the apex 4Bg1). The root diameter of the cam follower 7Ba is substantially equal to the groove width d7 of the cam groove 4Bd and does not enter the side of the cam groove 4Be having a narrow groove width at the intersection P21.

  The cam follower 9Ba of the fourth group frame 9B is formed of a truncated cone-shaped cam follower having a slit portion 9Ba1 at the center, and engages with the cam groove 4Be without play (with a small fitting gap). The cam follower height is substantially equal to or slightly lower than the groove depth h5 of the cam grooves 4Bd and 4Be. The groove width of the slit portion 9Ba1 is set to a groove width that engages the protrusion 4Bg without looseness (with a small fitting gap). Further, the direction of inclination of the slit portion 9Ba1 with respect to the optical axis O coincides with the direction of the cam bar S22.

  Here, the sliding operation of the cam followers 7Ba and 9Ba with respect to the cam grooves 4Bd and 4Be in the present embodiment having the above-described configuration will be described.

  At the time of assembly, the cam follower 9Ba needs to pass through the intersection P20 on the cam follower insertion portion 4Be1 of the cam groove 4Be as in the case of the first embodiment, but it should be inserted with care only at the time of assembly.

  When the lens barrel is extended from the retracted state to the wide state, one cam follower 9Ba passes through the intersection P21 of the cam groove 4Be between the retracted rotation position θ2C and the wide rotation position θ2W by the rotation of the cam frame 4B. When the cam follower 9Ba is within the cam groove crossing range, the slit portion 9Ba1 of the cam follower 9Ba is engaged with the protrusion 4Bg, and when the engagement with the protrusion 4Bg of the slit portion 9Ba1 is released, the cam follower 9Ba is out of the cam follower 9Ba. The diameter is engaged with the cam groove 4Be. Therefore, the cam follower 9Ba smoothly passes through the intersection P21 without dropping from the cam groove 4Be.

  The other cam follower 7Ba is zoomed out at the intersection P20 when the cam groove 4d is extended out of the imaging area (collapse rotation position θ1C to wide rotation position θ1W), and further within the imaging area (wide rotation position θ1W to tele rotation position θ1T). Passes the intersection P21 during operation.

  When the cam follower 7Ba passes through the intersection P20, the root diameter of the cam follower 7Ba is larger than the groove width of the cam groove 4Be1, and the cam follower 7Ba passes through the intersection P20 smoothly without dropping from the cam groove 4Bd. Also, when the cam follower 7Ba passes the intersection P21, the outer diameter portion is larger than the groove width d8 of the cam groove 4Bd, and the tip of the cam follower 7Ba does not interfere with the protrusion 4Bg. Therefore, the cam follower 7Ba smoothly passes through the intersection P21 without dropping from the cam groove 4Bd.

  According to the lens barrel of the present embodiment described above, the same effects as those of the first embodiment can be obtained. Particularly in the case of the present embodiment, the length of the protrusion 4Bg provided on the cam groove 4Be side is longer than the groove width d7 of the cam groove 4Bd, or the cam follower 9Ba does not have to be separated from the cam groove 4Be at the intersection. It is set to length. Therefore, the movement of the cam follower 9Ba on the intersection P21 is performed more smoothly. Further, since the cam follower 7Ba passes above the protrusion 4Bg on the intersection P21, the intersection passes smoothly without changing the sliding resistance.

  In this embodiment as well, the cam follower 7Ba passes through the intersection P21 between the wide rotation position θ1WC and the tele rotation position θ1T, which are the photographing range area. At this time, in order to give a smoother movement, the cam follower 7Ba is designed in terms of design dimensions. May reach the cam groove 4Be slightly.

  In order to suppress the wobbling of the second group frame 7B, the cam grooves 4Bd and 4Be and the rotational angle phase difference between the three pairs of cam grooves are the same as in the case of the modified cam grooves of the first and second embodiments described above. The same effect can be obtained by changing at.

  In each of the embodiments described above, the cam grooves are all bottomed grooves. However, these cam grooves perform the same function as long as at least the portions near the intersections P1, P11, and P21 are formed with bottomed grooves. The effect of can be produced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  The lens barrel of the present invention can be used as a lens barrel that can be smoothly advanced and retracted in a lens barrel provided with cam grooves that intersect with each other without dropping off at the intersection of the cam grooves.

It is sectional drawing in the retracted state containing the optical axis of the lens barrel which incorporates the lens barrel of 1st embodiment of this invention. It is sectional drawing in the wide state containing the optical axis of the lens-barrel of FIG. It is sectional drawing in the tele state containing the optical axis of the lens-barrel of FIG. FIG. 3 is an exploded perspective view of a cam frame, a float ring, a second group frame, and a fourth group frame as lens barrels constituting the lens barrel of FIG. 1. FIG. 5 is a development view showing a state in which one cam follower is positioned immediately before an intersection in an engaged state with a cam groove (showing a pair of three pairs) on the inner peripheral surface of the cam frame in FIG. 4 and a cam follower engaged with the cam groove. is there. FIG. 4 is a development view showing a state in which one cam follower is on an intersection in an engaged state with a cam groove (showing a pair of three pairs) on the inner peripheral surface of the cam frame in FIG. 4 and a cam follower engaged with the cam groove. It is. It is AA sectional drawing of FIG. FIG. 6 is a perspective view around the intersection of the cam follower and the cam groove in FIG. 5. It is BB sectional drawing of FIG. FIG. 6 is a development view showing cam grooves (showing a pair of three pairs) on an inner peripheral surface of a cam frame, a cam follower engaged with the cam grooves, and an engaged state in the lens barrel of the second embodiment of the present invention. . It is CC sectional drawing of FIG. It is a perspective view around the intersection of the cam follower and cam groove of FIG. It is DD sectional drawing of FIG. FIG. 10 is a development view showing a cam groove (showing a pair of three pairs) on an inner peripheral surface of a cam frame, a cam follower engaged with the cam groove, and an engaged state in a lens barrel of a third embodiment of the present invention. . It is a perspective view around the intersection of the cam follower and cam groove of FIG. It is EE sectional drawing of FIG.

Explanation of symbols

4,4A, 4B
... Cam frame (first frame member)
4e, 4Ae, 4Be
... Cam groove (first cam groove, bottomed groove)
4d, 4Ad, 4Bd
... Cam groove (second cam groove, bottomed groove)
4g, 4Ag, 4Bg
... Protrusions 7, 7A, 7B
... Second group frame (third frame member)
7a, 7Aa, 7Ba
... Cam follower (second groove follower)
7a1, 9a1, 9Aa1, 9Ba1
... Sliced portion (slit portion)
9, 9A, 9B
... Four-group frame (second frame member)
9a, 9Aa, 9Ba
... Cam follower (first groove follower)
P1, P11, P21
... Intersection (intersection)

Claims (8)

The first frame member having a projecting portion on the bottom of the intersecting portion or the vicinity thereof, where the bottomed grooves intersect with each other,
It has a slit shape that allows the projection to pass through at the tip, and engages with one of the bottomed grooves, slides in the bottomed groove, and has a groove follower that can pass through the intersection. A second frame member that moves relative to the first frame member;
A lens barrel characterized by having. The lens barrel according to claim 1, wherein the protrusion has a protrusion height lower than a depth dimension of the bottomed groove. The said protrusion protrudes in the shape of a long plate in the direction along one cam line | wire of the said bottomed groove | channel, This protrusion height is lower than the depth dimension of the said bottomed groove | channel. The lens barrel described. A first frame member having a first groove and a second groove intersecting the first groove, and having a projection on the bottom surface in the vicinity of the intersecting portion or the vicinity thereof;
It has a first groove follower that has a slit shape that engages with the first groove and allows the protrusion to pass through at the tip, and the first groove follower can pass through the intersection. A second frame member that moves relative to the first frame member;
Engage with the second groove, and has a projecting second groove follower whose height is lower than the projecting height of the first groove follower, and the second groove follower can pass through the intersection. A third frame member that moves relative to the first frame member;
A lens barrel characterized by comprising: The lens barrel according to claim 4, wherein the protrusion at the intersecting portion has a protrusion height that does not interfere with the second groove follower. The lens barrel according to claim 4, wherein the first groove is narrower than the second groove. A first frame member having a first groove and a second groove intersecting with the first groove, and having a protrusion on a bottom surface of the intersecting portion or the vicinity thereof;
A first groove follower that engages with the first groove, a slit shape that allows the protrusion to pass through is provided at the tip of the first groove follower, and can pass through the intersection. A second frame member that moves relative to the first frame member;
A second groove follower that engages with the second groove, a slit shape is provided at a tip of the second groove follower through which the protrusion can pass, and can pass through the intersecting portion; A third frame member that moves relative to the first frame member;
A lens barrel characterized by comprising: A first groove and a second groove that is deeper than the first groove and intersects the first groove, and a bottom surface of the intersecting portion of the first groove or the vicinity thereof A first frame member having a protrusion on the
It has a first groove follower that has a slit shape that engages with the first groove and allows the protrusion to pass through at the tip, and the first groove follower can pass through the intersection. A second frame member that moves relative to the first frame member;
A second groove follower that engages with the second groove and has a height greater than the depth of the first groove, the second groove follower being capable of passing through the intersection, A third frame member that moves relative to the one frame member;
A lens barrel characterized by comprising:

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