JP2007248642A - Lens barrel and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel and an imaging device capable of thinning in the optical axis direction and miniaturizing the whole imaging device, and obtaining high image quality, and also taking fine moving images. <P>SOLUTION: This lens barrel has a CCD7 to receive the light of an object through the imaging lens and to make photoelectric conversion, and a low-pass filter 6 arranged in front of the CCD7. Further, it has a bellows 29 to support the low-pass filter 6 to the CCD 7 while making the low-pass filter 6 free to move back and forth in the optical axis direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel in which an optical filter is disposed on the front surface of an image sensor and an image pickup apparatus using the lens barrel, and in particular, in the optical axis direction of the optical filter with respect to the image sensor during shooting and during non-shooting. The present invention relates to a lens barrel and an imaging apparatus that can reduce the reflection of foreign matter adhering to an optical filter by changing the position, and can reduce the thickness of the lens barrel.

  As a conventional lens barrel of this type, for example, there is one described in Patent Document 1. Patent Document 1 describes an electronic camera configured to electronically record image information. The electronic camera according to Patent Document 1 is “an electronic camera including an image sensor that receives and photoelectrically converts a subject light beam that has passed through a photographing lens, and has a frame shape that includes a cover glass of the image sensor and an opening. A sealed space is formed by the optical member disposed on the photographing lens side with the spacer interposed therebetween, and the spacer is formed of a charging material, and an adhesive is applied to the inner peripheral surface of the opening. '' It is characterized by that.

According to the electronic camera described in Patent Document 1 having such a configuration, “the dust can be removed from the shooting range by adsorbing to the spacer, and the dust once adsorbed to the spacer can be returned to the shooting range again. It can be prevented ”(paragraph [0036] of the specification).
JP 2003-37756 A

  However, in the electronic camera described in Patent Document 1 described above, both the low-pass filter, which is an optical member, and the image sensor are attached to the camera body, and the distance between the image sensor in the optical axis direction of the low-pass filter is fixed. It was. For this reason, when a foreign object adheres to the surface of the low-pass filter, the foreign object is imprinted on the light receiving surface of the image sensor together with the image of the subject, and there is a problem that the imprint of the foreign object occurs.

  In general, a lens barrel needs to prevent light from entering from a portion (gap) other than the lens system that passes through the taking lens, while the movable lens is used to perform focusing, zooming, and other functions. It is necessary to move in the axial direction. For this reason, consideration has been given to make the gap in the lens barrel portion that relatively rotates and slides as small as possible. However, in order to ensure the rotation and sliding, a gap of a certain size is required. Is required. As a result, foreign matter may enter the lens barrel through a gap such as a rotating part or sliding part, and the foreign matter adheres to the surface of the low-pass filter disposed on the front surface of the image sensor, and the foreign matter is reflected. In some cases, it was a cause of confusion.

  Furthermore, the smaller the distance in the optical axis direction between the image sensor and the low-pass filter, the easier it is for foreign matter attached to the surface of the low-pass filter to appear. For this reason, the distance between the low-pass filter and the image sensor cannot be made narrower than a certain distance (about 3 mm is the limit). Therefore, in the case of the conventional example in which both the image sensor and the low-pass filter are fixed to the camera body, it is necessary to secure the minimum distance, so the length of the lens barrel in the optical axis direction is shortened. It was difficult. It is also possible to reduce the size of the lens barrel by reducing the aperture mechanism. However, if the optical minimum aperture is reduced, foreign matter adhering to the surface of the low-pass filter is easily reflected, so the minimum aperture is reduced. I couldn't do that either.

  On the other hand, in recent years, it has been strongly desired to reduce the size of the lens unit, in particular, to reduce the thickness in the optical axis direction. Furthermore, not only high-quality still images but also high-quality moving images are demanded, and there is an increasing need to overcome the factors that hinder downsizing as described above.

  The problem to be solved is that in the lens barrel of the conventional electronic camera, it is difficult to reduce the size of the lens unit, in particular, to reduce the thickness in the optical axis direction. It is that it cannot be obtained.

  The lens barrel of the present invention is a lens barrel that includes an imaging device that receives and photoelectrically converts light of a subject that has passed through a photographing lens, and an optical filter that is disposed in front of the imaging device, The most important feature is that an advance / retreat support member for supporting the optical filter on the image sensor so as to be able to advance / retreat in the optical axis direction of the photographing lens is provided.

  An image pickup apparatus according to the present invention is an image pickup apparatus including a lens barrel having an image pickup element that receives and photoelectrically converts light of a subject that has passed through a photographing lens, and an optical filter that is disposed in front of the image pickup element. The lens barrel is provided with an advancing / retracting support member that supports the imaging element so that the optical filter can advance and retreat in the optical axis direction of the photographing lens.

  According to the lens barrel and the imaging apparatus of the present invention, the optical filter disposed in front of the imaging device is configured to be movable back and forth in the optical axis direction. While reducing the reflection, the optical filter should be as close as possible to the image sensor when not photographing. Accordingly, it is possible to reduce the thickness of the lens barrel in the optical axis direction and to reduce the size of the entire imaging apparatus, to obtain high-quality image quality, and to enable beautiful moving image shooting.

  By adopting a configuration in which the optical filter is supported by the imaging element so as to be able to advance and retract in the optical axis direction of the photographing lens, the lens barrel can be thinned in the optical axis direction and the entire imaging apparatus can be reduced in size. A lens barrel and an imaging device that can obtain image quality and moving images are realized with a simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 to 32 illustrate an example of an embodiment of the present invention. 1A and 1B are perspective views of a lens barrel storage state and a lens barrel feeding state showing a first embodiment of the lens barrel cam mechanism of the present invention, and FIG. 2 is an exploded view of the lens barrel of FIG. FIG. 3 is a sectional view of the lens barrel stored, FIG. 4 is a sectional view of the lens barrel extended state, FIG. 5 is a perspective view of the stationary ring, FIG. 6 is an exploded view of the stationary ring, and FIGS. FIGS. 8A and B are a plan view and a bottom view of the cam ring, and FIGS. 9A and 9B are developed views of the outer peripheral surface and the inner peripheral surface of the cam ring. 10 is a development view of the straight travel regulating member, and FIG. 11 is a development view of the straight travel ring.

  12 is a perspective view of the automatic exposure apparatus, the interval regulating member, and the second group ring, FIG. 13 is a development view of the second group ring, FIG. 14 is a perspective view of the first group lens and the first group ring, and FIG. FIGS. 16 to 22 illustrate the relationship between the first group ring and the cam ring. FIGS. 16A and 16B are perspective and sectional views of the assembled state of the first group ring and the cam ring. FIGS. 18A and 18B are a front view and a bottom view in an assembled state, FIGS. 19A and 19B are a right side view and a cross-sectional view taken along line YY in FIG. 18B, and FIGS. 20A and 20B are perspective views on the bottom side. FIG. 21 is an enlarged view of the main part, FIG. 21 is a perspective view showing a state in which the first group ring is moved to the tip side of the cam ring, and FIGS.

  23 is a perspective view of the second group ring, the third group lens frame, and the CCD unit as seen from the front side, FIG. 24 is a perspective view of the same as seen from the back side, FIG. 25 is an exploded perspective view of the CCD unit, and FIG. 27 is a partial sectional perspective view of the first embodiment of the advance / retreat support member, FIG. 27 is a partial sectional perspective view of the second embodiment of the advance / retreat support member, and FIG. 28 is a part of the third embodiment of the advance / retreat support member. It is a cross-sectional perspective view. Further, FIG. 29 shows a first embodiment of a digital still camera using the lens barrel of FIG. 1 and the like, and is a front perspective view of the lens barrel stored state, and FIG. 30 is a front side of the lens barrel extended state. 31 is a rear perspective view, and FIG. 32 is a block diagram for explaining a schematic configuration of the digital still camera shown in FIG.

  A lens barrel 1 shown in FIGS. 1 to 4 shows a first embodiment of the lens barrel of the present invention, and includes a photographing optical system composed of a plurality of optical elements such as lenses and filters, It consists of a mechanic system such as a ring or a frame that supports each component of the photographing optical system so as to be fixed or movable, and a power system such as a motor or gear that operates the mechanic system.

  As shown in FIGS. 2 to 4, the imaging optical system of the lens barrel 1 includes a first lens group 2 composed of a combination of a plurality of lenses arranged in order from the subject side, and an automatic exposure that is a shutter and an iris unit. A device 3, a second lens group 4 composed of a combination of a plurality of lenses, a third lens group 5 composed of a combination of one or more lenses, a low-pass filter 6 showing a first specific example of an optical filter, An image sensor (CCD) 7 is used. The zoom function is exhibited by the first lens group 2 and the second lens group 4, and the zooming operation of the optical system can be executed by moving both the lens groups 2 and 4 by a predetermined amount in the optical axis direction. The focusing function is exhibited by the third lens group 5, and the focusing operation of the optical system can be executed by moving the third lens group 5 by a predetermined amount in the optical axis direction.

  The mechanic system of the lens barrel 1 includes, in order from the subject side, a first group ring 10 showing a first specific example of a rectilinear member, a first group lens frame 11 that holds the first lens group 2, and a second rectilinear member. A second group ring 12 showing a specific example, a second group lens frame 13 holding the second lens group 4, a rectilinear ring 14, a cam ring 15 showing a specific example of a rotating member, and a camera such as a digital still camera A fixed ring 16 fixed to the main body, a third group lens frame 17 holding the third lens group 5, a rear barrel 18 fixed to the rear part of the fixed ring 16, and the like. A CCD unit 20 having an image sensor (CCD) 7 is attached to the rear barrel 18.

  The power system of the lens barrel 1 includes a reduction gear unit 21 and a drive gear 22 that rotate the cam ring 15, an F motor unit 23 that performs a focusing operation of the optical system, and the like. The reduction gear unit 21 and the F motor unit 23 are attached to the assembly of the stationary ring 16 and the rear barrel 18. The drive gear 22 is rotatably supported by the fixed ring 16 and the rear barrel 18.

  The rear barrel 18 has a ring-shaped rear surface portion 18a in which a substantially rectangular through hole 25 is provided in the center portion, and an inner side that protrudes to one side so as to surround the through hole 25 of the rear surface portion 18a. A boss portion 18b and an outer boss portion 18c formed on one side of the outer surface of the rear surface portion 18a so as to protrude from the one surface side. A unit support portion for supporting the F motor unit 23 on a part of the outer boss portion 18c. 26 is provided. On the back side of the inner boss portion 18b of the rear barrel 18, a seat portion 18d is provided by denting the periphery thereof, and the CCD unit 20 is mounted on the seat portion 18d.

  The fixed ring 16 fixed to the front part of the rear barrel 18 has a configuration as shown in FIG. The fixed ring 16 is formed of a substantially cylindrical cylinder that is an exterior body of the lens barrel 1, and all of the photographing optical system can be accommodated in the fixed ring 16. As shown in the development view of FIG. 6, the front surface portion 16a in the optical axis direction, which is one end surface of the fixed ring 16, is a flat portion perpendicular to the optical axis direction, but light that is the other end surface. The rear surface portion 16b in the axial direction is formed with irregularities by a predetermined step in the optical axis direction. The unevenness of the rear surface portion 16 b is provided so as to correspond to the unevenness of the joint portion of the rear barrel 18. Further, the fixed ring 16 is provided with a first notch 33 for exposing a part of the drive gear 22 and a second notch 34 for exposing a part of the third group lens frame 17. Yes.

  The first notch 33 and the second notch 34 of the fixed ring 16 are opened to the rear surface portion 16b. A bearing portion 16c that supports one end in the axial direction of a support shaft 35 that rotatably supports the drive gear 22 is provided on the outer surface of the fixed ring 16 corresponding to the first notch 33. A support portion 16 d that supports a part of the F motor unit 23 is provided on the outer surface of the stationary ring 16 corresponding to the second notch 34. Further, on the inner peripheral surface of the fixed ring 16, two types of cam grooves 37A, 37B, and 37C having the same cam curve, and three types of five linearly extending straight in the optical axis direction Guide grooves 38A, 38B, and 38C are provided.

  A total of three types of cam grooves 37A, 37B, and 37C of the fixed ring 16 are continuous with the inclined surface portion 37a spirally extending in the circumferential direction and the front surface portion 16a side of the inclined surface portion 37a and in the optical axis direction. The front horizontal portion 37b extending in the circumferential direction orthogonal to the surface and the rear surface portion 16b side of the inclined surface portion 37a is a circumferential direction orthogonal to the optical axis direction and opposite to the front horizontal portion 37b. And a rear horizontal portion 37c extending in the direction. The widths of the slope portions 37a of the three cam grooves 37A to 37C are the same, but the width directions of the slope portions 37a of the two first cam grooves 37A and 37B, which are the first type, are set in the width direction. A central ridge 39 is provided so as to divide into two. A right passage 39a and a left passage 39b extending in parallel with each other are formed in the slope portion 37a by the central protrusion 39.

  A total of three cam grooves 37A to 37C including two first cam grooves 37A and 37B provided with such a structural difference and one second cam groove 37C of the second type are provided. They are arranged at substantially equal intervals in the circumferential direction on a plane perpendicular to the optical axis direction. Three cam followers (described later) provided in the cam ring 15 are slidably engaged with the three types of cam grooves 37 </ b> A to 37 </ b> C in total of two types having such a configuration.

  On the other hand, a total of two types of five straight guide grooves 38A and 38B are arranged in parallel with each other at an appropriate interval in the circumferential direction on a plane perpendicular to the optical axis direction. The two first straight guide grooves 38A, 38A, which are the first type, guide the straight ring 14 in the optical axis direction. Cam followers, which will be described later, provided in the linearly moving ring 14 are slidably engaged with the two first linearly guiding grooves 38A, 38A. The two first rectilinear guide grooves 38A and 38A are arranged at predetermined intervals on one side (left side in FIG. 6) of the first cam grooves 37A and 37B, respectively. The two first rectilinear guide grooves 38A, 38A are provided so as to intersect with the front horizontal portions 37b of the first and second cam grooves 37A, 37B, respectively.

  On the other hand, the three second rectilinear guide grooves 38B, 38B, 38C, which are the second type, guide a rectilinear restricting member, which will be described later, in the optical axis direction. Of the three second rectilinear guide grooves 38B, 38B, 38C, the two second rectilinear guide grooves 38B, 38B are provided so as to intersect with the inclined surface portion 37a of the first cam groove 37A, respectively. ing. Thereby, each slope part 37a is each provided with the cut-out part 41 which divides | segments the center protrusion 39 in the diagonal direction. On the other hand, the remaining one second rectilinear guide groove 38C is provided so as to intersect the front horizontal portion 37b of the third cam groove 37C, similarly to the first rectilinear guide groove 38A.

  The stationary ring 16 having such a configuration is disposed on the front side of the rear barrel 18 and is detachably fixed by a plurality of fixing screws. A support shaft 35 is held by a lens barrel assembly of the fixed ring 16 and the rear lens barrel 18, and some teeth of the drive gear 22 rotatably supported by the support shaft 35 have a tooth width. It is exposed to the outside of the lens barrel assembly from the first notch 33 over substantially the entire length in the direction. The reduction gear unit 21 is detachably attached to the bearing portion 16c of the fixed ring 16 and the flange portion of the rear barrel 18 so as to cover the exposed portion of the drive gear 22, and is fastened and fixed with a plurality of fixing screws. Has been.

  As shown in FIG. 2, the reduction gear unit 21 includes an output gear (not shown) meshed with the drive gear 22, one or more reduction gears that transmit power to the output gear, and power via the reduction gear. The zoom motor 44 that rotates the output gear by transmitting the output gear, and the housing 45 that rotatably supports the output gear and other gears, and that supports the zoom motor 44 fixedly. The housing 45 is fastened and fixed to the barrel assembly with a fixing screw, so that the reduction gear unit 21 is attached so as to be assembled and disassembled. The reduction gear unit 21 is provided with a rotation detector such as a rotary encoder that detects the number of rotations of the zoom motor 44 and outputs a detection signal thereof.

  The unit support portion 26 of the rear barrel 18 includes a pair of support pieces that support the F motor unit 23 so as to hold the F motor unit 23, and the pair of support pieces protrude forward so as to be substantially parallel with an appropriate gap. Has been. The F motor unit 23 held by the unit support portion 26 and the support portion 16d of the fixed ring 16 serves as a power source for causing the lens barrel 1 to perform a focusing operation. The F motor unit 23 includes a focus motor 46, a motor bracket 47 that fixes and supports the focus motor 46, a carriage 48 that is movably screwed to a rotation shaft 46a of the focus motor 46, and the carriage 48 that is a rotation shaft. The guide bar 49 etc. which guide substantially parallel to the axial direction of 46a are comprised.

  The motor bracket 47 is formed in a U-shape, and the focus motor 46 is fixed to the outside of one rising piece. The rotation shaft 46a of the focus motor 46 is composed of a feed screw shaft, and the rotation shaft 46a passes through one rising piece, and its tip is rotatably supported by the other rising piece. Between the rising pieces, a carriage 48 is screwed onto the rotary shaft 46a so as to be movable in the axial direction. A guide bar 49 having a shaft center line set substantially parallel to the shaft center line of the rotating shaft 46a is slidably passed through the carriage 48. Both end portions of the guide bar 49 in the axial direction are supported by the motor bracket 47, and the carriage 48 is guided by the guide bar 49 so as to be movable back and forth in the optical axis direction.

  The third lens group 5 can be moved back and forth in the optical axis direction by the F motor unit 23 having such a configuration. The third lens group 5 is disposed in front of the low-pass filter 6 disposed in front of the CCD 7 and is held by a third group lens frame 17. As shown in FIGS. 23 and 24, the third group lens frame 17 includes a lens holding portion 17a that holds the third lens group 5, and an arm portion 17b that is continuous on one side of the lens holding portion 17a. ing. The arm portion 17 b is provided with a sliding bearing portion 53 a through which the guide shaft 51 is slidably inserted, and an engaging portion 53 b that is engaged with the carriage 48 of the F motor unit 23.

  Further, a front convex portion 56a that is in contact with the convex portion 12d provided on the second group ring 12 is provided on the surface of the lens holding portion 17a of the third group lens frame 17 on the second group ring 12 side (FIG. 23). See). Then, on the surface of the lens holding portion 17a on the CCD unit 20 side, four rear-side projections that abut first on the four pressure-receiving projections 137 provided on the filter pressing plate 31 described later before other portions come into contact with each other. Portions 56b and 56b are provided (see FIG. 24).

  One end of a third group spring 52 made of a coil spring is engaged with the third group lens frame 17. The other end of the third group spring 52 is locked to the fixed ring 16, and the engaging portion 17 d of the third group lens frame 17 is always pressed against the carriage 48 by an appropriate urging force by the spring force of the third group spring 52. It has been. Thus, when the focus motor 46 of the F motor unit 23 is rotationally driven, the carriage 48 is guided by the guide bar 49 against the spring force of the third group spring 52 according to the rotational direction, and advances and retreats in the optical axis direction. Moving. As a result, a predetermined zooming operation is executed by moving the third lens group 5 by a predetermined amount in the optical axis direction according to the rotation amount of the F motor unit 23.

  A cam ring 15 is disposed inside the fixed ring 16. The cam ring 15 has a configuration as shown in FIGS. The cam ring 15 includes a cylindrical body portion 15a having an outer diameter slightly smaller than the inner diameter of the fixed ring 16, and a flange portion 15b continuous to one end face side of the body portion 15a. The flange portion 15b is in the radial direction. Expanded outward. The flange portion 15b includes an arc-shaped first flange portion 54a that occupies a portion extending over approximately half of the circumferential direction, and an arc-shaped second flange disposed on the opposite side so as to face the first flange portion 54a. The flange portion 54b. The second flange portion 54b is formed as a region that occupies a portion extending over approximately 1/6 in the circumferential direction, and the second flange portion 54b is located on both sides of the circumferential direction and between the first flange portion 54a and the second flange portion 54b. A first cutout portion 55a and a second cutout portion 55b having the same size as the flange portion 54b are provided.

  As shown in FIGS. 8A and 8B, the flange portion 15b of the cam ring 15 is provided with three cam protrusions 57A, 57B, and 57C showing the first embodiment of the cam follower. The three cam projections 57A, 57B, and 57C are arranged at substantially equal intervals in the circumferential direction, and the first cam projection 57A is provided on one side of the first flange portion 54a, and the second cam projection The portion 57B is provided on the other side of the first flange portion 54a, and the third cam projection 57C is provided on the second flange portion 54b. Of the three cam projections 57A to 57C, engagement grooves 58 extending in an oblique direction are provided at the tips of the first and second cam projections 57A and 57B, respectively.

  The three cam protrusions 57A to 57C are slidably engaged with three cam grooves 37A, 37B, and 37C provided on the inner peripheral surface of the fixed ring 16. The three cam protrusions 57A to 57C are formed so as to correspond to the three cam grooves 37A, 37B, and 37C, and the respective engagement grooves provided in the first and second cam protrusions 57A and 57B. 58, the central protrusions 39 provided in the first and second cam grooves 37A and 37B are respectively slidably engaged. As described above, the central protrusion 39 is provided on the wide inclined surface portion 37a of the cam grooves 37A to 37C to form the left and right passages 39a and 39b, so that the second linear guide extending in a direction intersecting with the left and right passages 39a and 39b. A follower of a straight movement restricting member, which will be described later, that moves along the groove 38B can smoothly move straight without being disengaged from the second straight movement guide groove 38B.

  The three cam protrusions 57A to 57C are set on the same plane perpendicularly intersecting the axial center line of the body part 15a. However, as shown in FIGS. 7A and 7B, only the third cam protrusion 57C is provided. Is formed thinner than the other cam projections 57A and 57B. A gear portion 60 formed of spur teeth is provided on the first flange portion 54a of the flange portion 15b so as to surround the third cam protrusion 57C. The gear portion 60 is continuous to one side in the circumferential direction of the first cam projection 57A and has the same gear width on the outer side in the axial direction of the third cam projection 57C. The second gear portion 60b formed with the same tooth width as that of the first gear portion 60a and the first gear portion 60a and the second gear portion 60b are connected to each other and have a combined tooth width. It consists of a third gear portion 60c.

  The drive gear 22 is always meshed with the gear portion 60 at any one of the gear portions 60a to 60c. Thereby, when the drive gear 22 is rotationally driven by the operation of the reduction gear unit 21, the cam ring 15 is rotated to the left or the right according to the rotation direction. The circumferential length of the gear portion 60 has the number of teeth necessary for the cam ring 15 to rotate by a predetermined angle. Therefore, when the cam ring 15 is rotated by the drive gear 22, the cam ring 15 simultaneously moves in the axial direction, but the drive gear is larger than the movement amount (stroke) of the cam ring 15 in the axial direction. Since the tooth width of 22 is set to be sufficiently long, the rotation operation within a predetermined range is executed in a state where the drive gear 22 and the gear portion 60 are always meshed.

  Further, the first flange portion 54 a of the flange portion 15 b of the cam ring 15 is provided with a fin 61 for detecting the rotational position of the cam ring 15. The fin 61 is formed to have a predetermined length in the circumferential direction continuously to the end of the first flange portion 54a on the third cam protrusion 57C side. Although not shown, the rear lens barrel 18 is provided with a photosensor to detect the fins 61. When the photosensor is switched by the movement of the fin 61, the rotational position of the cam ring 15 can be detected. Based on the rotational position information obtained by the rotational position detecting means and the detection information obtained by the rotary encoder provided in the reduction gear unit 21 described above, the information is processed by a control device described later, whereby the cam ring 15 is processed. It is possible to control the rotation speed and the rotation position.

  Furthermore, the first flange portion 54a of the flange portion 15b of the cam ring 15 is provided with a through hole 62 that passes through the first flange portion 54a in the tooth width direction. The through hole 62 is formed in an arc shape so as to be concentric with the outer peripheral surface of the body portion 15a or the teeth of the gear portion 60 at a position opposite to the second flange portion 54b. The end portion of the body portion 15a facing the through hole 62 is formed in the same manner as the shapes of the first and second cutout portions 55a and 55b, as will be described later.

  Three outer cam grooves 65 having the same cam curve (trajectory) are provided on the outer periphery of the body portion 15 a of the cam ring 15. The three outer cam grooves 65 give the lens barrel 1 an optical zooming operation and a barrel storage operation, and are arranged at substantially equal intervals in the circumferential direction. As shown in FIGS. 7A, 7B, and 9A, the three outer cam grooves 56 include a lens barrel storage operation region 66 that imparts a lens barrel storage operation, and a zooming operation region 67 that is continuous with the lens barrel storage operation region 66. It consists of and. The lens barrel storing operation area 66 of the outer cam groove 65 is spirally extended in an oblique direction with an inclination angle of about 45 degrees on the outer peripheral surface of the body portion 15a. One end of the lens barrel storage operation region 66 is opened at the end of the body portion 15a on the flange portion 15b side, and one end of the zooming operation region 67 is continuous with the other end.

  The zooming operation area 67 of the outer cam groove 65 is a zoom groove 67a formed of a groove formed in an arc shape by a predetermined curve, and a groove that gently communicates one end of the zoom groove 67a and the lens barrel storage operation area 66. A communicating portion 67b and a closing portion 67c or an opening portion 67d comprising a groove that is closed at the other end of the body portion 15a opposite to the flange portion 15b (on the opposite flange side). Have. The zoom groove portion 67a of the zooming operation region 67 is formed so as to protrude toward the flange portion 15b on the opposite flange side of the body portion 15a. The communication portion 67b of the zooming operation region 67 is formed by a groove in which a plurality of straight portions are gently continued. Moreover, the closing part 67c and the open part 67d are formed of grooves that are continuous in the circumferential direction.

  In order to form the communication portion 67b and the closing portion 67c or the opening portion 67d, three types of protrusions 68a, 68b, and 68c are provided on the opposite side of the body portion 15a. The three first protrusions 68a provided to correspond to the communication portion 67b are formed of trapezoidal portions having inclined surfaces on both sides. In addition, one second projecting portion 68b provided corresponding to the closing portion 67c and two third projecting portions 68c, 68c provided corresponding to the open portion 67d have inclined surfaces only on one side. It has a trapezoidal part. On the other hand, the two third projecting portions 68c and 68c are configured such that the cam groove is located on the end surface side of the body portion 15a by setting the vertical surface to the middle portion of the cam groove, as shown by a two-dot chain line in FIG. 9A. To open.

  An opening end of the outer cam groove 65 on the side of the flange portion 15b in the lens barrel storing operation region 66 forms a groove opening portion 71 through which a cam follower, which will be described later, of the first group ring 10 enters and exits. A pressing portion 72 that presses the cam follower of the first group ring 10 and transmits the rotational force of the cam ring 15 to the first group ring 10 is provided outside the side surface of one cam groove that forms the cam groove opening 71. It has been. Furthermore, a holding portion 73 that holds the cam follower at a position away from the outer cam groove 65 is provided on the opposite side of the cam groove opening 71 from the pressing portion 72.

  As shown in FIGS. 7A, C, and 9B, three sets of inner cam groove groups 74 having the same cam curve (trajectory) are arranged at equal intervals in the circumferential direction on the inner periphery of the body portion 15a of the cam ring 15. Has been provided. The three sets of inner cam groove groups 74 include a combination of a front inner circumferential cam groove 75 and a rear inner circumferential cam groove 76 having the same cam curve (trajectory). The front inner cam groove 75 and the rear inner cam groove 76 are set at a predetermined distance in the axial direction of the body portion 15a, which is the optical axis direction, and also slightly deviated in the circumferential direction. Are provided in a slightly twisted state.

  The basic cam curve of the front inner peripheral cam groove 75 and the rear inner peripheral cam groove 76 includes a first inclined surface portion 77a inclined in the same direction as the lens barrel storing operation region 66 of the outer cam groove 65, and its first A second inclined surface portion 77b inclined to the opposite side of the first inclined surface portion 77a, a horizontal portion 77c continuously extending in the circumferential direction at one end of the first inclined surface portion 77a and one end of the second inclined surface portion 77b, An open portion 77d continued to the other end of the slope portion 77a, and a circulation portion 77e continued to the other end of the second slope portion 77b. The first inclined surface portion 77a is inclined at an angle of approximately 45 degrees, but the midway portion is slightly bent rearward. Further, the second inclined surface portion 77b and the circulating portion 77e are connected by a connecting portion curved to the front side, and move in the circumferential direction within the circulating portion 77e and return to the second inclined surface portion 77b. Yes.

  The front inner peripheral cam groove 75 and the rear inner peripheral cam groove 76 having such a basic cam curve are the front inner peripheral cam groove 75, most of the first slope portion 77 a, the horizontal portion 77 c, and the second portion. The slope portion 77b and the circulation portion 77d are provided. On the other hand, the rear inner peripheral cam groove 76 is composed of only a part of the first slope portion 77a and the opening portion 77d. That is, the first inclined surface portion 77a of the front inner peripheral cam groove 75 is opened at the end face of the protruding portion 68b in the first inner cam groove group 74, and protrudes in the second and third inner cam groove groups 74. Opened on the side surfaces of the portions 68c, 68c. A part of the horizontal portion 77c of the front inner circumferential cam groove 75 is opened on the flange-side end surface of the body portion 15a.

  Further, the rear inner peripheral cam groove 76 is provided with only an opening portion 77d and a portion of the first slope portion 77a on the opening portion 77d side. That is, one end of the opening portion 77d is opened on the end surface on the opposite side of the body portion 15a, and one end of the first inclined surface portion 77a is opened on the end surface on the flange side of the body portion 15a. In addition, each opening portion of the front inner peripheral cam groove 75 and the rear inner peripheral cam groove 76 is provided with an introductory portion 78 that widens toward the end in order to facilitate the entry and exit of the follower cam.

  The flange portion 15b of the cam ring 15 having such a configuration is fitted with a rectilinear regulating member 80 that is restricted so as to be rotatable in the rotational direction but not movable in the optical axis direction. As shown in FIGS. 2 and 10, the rectilinear regulating member 80 includes a ring portion 80a having a ring shape having an outer diameter and an inner diameter substantially the same as the outer diameter and inner diameter of the body portion 15a, and an inner portion of the ring portion 80a. It has two rectilinear guide pieces 80b and 80b that are continuous to the periphery, and two convex part pieces 80c and 80c that are continuous to the outer periphery of the ring portion 80a. Three cutouts 81 for avoiding contact with a cam follower of the first group ring 10 to be described later are provided at equal intervals in the circumferential direction on the outer periphery of the ring portion 80a of the straight travel regulating member 80.

  The two rectilinear guide pieces 80b and 80b of the rectilinear regulating member 80 are disposed so as to oppose the position rotated and rotated by 180 degrees, and are formed to project in a direction perpendicular to the surface direction of the ring portion 80a. . The two rectilinear guide pieces 80b and 80b are slidably engaged with two rectilinear guide grooves (to be described later) of the second group ring 12. The two convex pieces 80c, 80c are formed so as to protrude outward in the radial direction with a predetermined interval in the circumferential direction. The two convex pieces 80c and 80c are slidably engaged with the above-described two first rectilinear guide grooves 38A and 38A of the fixed ring 16. As shown in FIGS. 7C and 8B, a ring-shaped seat portion 15 c is provided on the inner periphery of the flange portion 15 b of the cam ring 15 in order to accommodate the ring portion 80 a of the straight movement restricting member 80 in a rotatable manner. ing.

  On the inner periphery of the cam ring 15, a second group ring 12 whose rotational movement is restricted by the straight advance restriction member 80 and which can move only in the optical axis direction is mounted. As shown in FIGS. 12 and 13, the second group ring 12 has a cylindrical cylindrical body portion 12 a and an inner flange portion that is developed radially inward in an axially middle portion of the cylindrical body portion 12 a. And a group lens frame 12b. A boss portion 12c is provided on the inner periphery of the second group lens frame 12b of the second group ring 12, and a second lens group 4 made of a combination of a plurality of lenses is attached to the boss portion 12c.

  On the outer periphery of the cylindrical body portion 12a of the second group ring 12, there are provided two rectilinear guide grooves 83 and 83 into which the two rectilinear guide pieces 80b and 80b of the rectilinear regulating member 80 are slidably engaged. Yes. The two rectilinear guide grooves 83 and 83 are arranged at positions that are rotated and displaced by 180 degrees, and are formed in a straight line so as to be parallel to the optical axis direction. Further, three sets of cam pin groups 84 that are slidably engaged with three sets of inner cam groove groups 74 provided on the inner periphery of the cam ring 15 are provided on the outer periphery of the cylindrical portion 12a. The three sets of cam pin groups 84 have the same height in the optical axis direction and are arranged at equal intervals in the circumferential direction.

  Each cam pin group 84 is composed of a front cam pin 85 and a rear cam pin 86 arranged in the front and rear direction in the optical axis direction. The front cam pin 85 and the rear cam pin 86 are provided with a slight deviation in the circumferential direction. The front cam pin 85 of the cam pin group 84 is engaged with the front inner peripheral cam groove 75 of the inner cam groove group 74, and the rear cam pin 86 is engaged with the rear inner peripheral cam groove 76. At this time, the two rectilinear guide grooves 83 and 83 provided on the outer periphery of the second group ring 12 are engaged with the two rectilinear guide pieces 80 b and 80 b of the rectilinear restriction member 80, while the rectilinear restriction member 80. The two convex pieces 80c, 80c are slidably engaged with the two first straight guide grooves 38A, 38A of the stationary ring 16. Therefore, when the cam ring 15 is rotated, the second group ring 12 does not rotate with respect to the fixed ring 16, and the inner cam groove group 74 set by the front inner cam groove 75 and the rear inner cam groove 76. It moves forward and backward only in the optical axis direction along the cam curve.

  The operation of the second group ring 12 and the cam ring 15 by the cam mechanism is as follows. A state in which the second group ring 12 is completely accommodated in the cam ring 15 is a non-photographing state of the imaging apparatus. At this time, the front cam pin 85 is positioned in the circulating portion 77e of the front inner peripheral cam groove 75, while the rear cam pin 86 protrudes rearward from the body portion 15a and is not engaged with the rear inner cam groove 76. When the cam ring 15 is rotated in the feeding direction from this non-photographing state, the front cam pin 85 moves from the circulating portion 77e to the second inclined surface portion 77b due to the engagement between the front inner peripheral cam groove 75 and the front cam pin 85. . As a result, the second group ring 12 moves back and forth in the optical axis direction without rotating.

  When the cam ring 15 is further rotated in the feeding direction, the front cam pin 85 moves on the second inclined surface portion 77b and reaches the horizontal portion 77c. As a result, the cam engagement between the front cam pin 85 and the front inner circumferential cam groove 75 is released, but one end of the second group ring 12 is brought into contact with the straight movement restricting member 80, so that the front cam pin 85 is moved to the front inner circumferential cam groove 75. Will not fall out completely. When the cam ring 15 is continuously rotated in the feeding direction, the front cam pin 85 enters the first inclined surface portion 77a, and the front cam pin 85 is cam-engaged with the front inner peripheral cam groove 75 again. When the cam ring 15 is further rotated, the rear cam pin 86 approaches the rear inner peripheral cam groove 76, and then the cam pin 86 is cam-engaged with the rear inner peripheral cam groove 76. As a result, the front and rear cam pins 85 and 86 are cam-engaged with the front and rear inner circumferential cam grooves 75 and 76.

  When the cam ring 15 is further rotated in the feeding direction, the second group ring 12 advances greatly and the front cam pin 85 passes through the first inclined surface portion 77a, so that the cam engagement between the front cam pin 85 and the front inner peripheral cam groove 75 occurs. The match will be missed. However, in this case, the rear cam pin 86 is cam-engaged with the rear inner peripheral cam groove 76, thereby ensuring further cam engagement. Therefore, the second group ring 12 can be further moved forward by cam engagement of only the rear cam pin 86 and the rear inner peripheral cam groove 76. At this time, since the front end and the rear end of the front inner peripheral cam groove 75 and the opening portion of the rear end of the rear inner peripheral cam groove 76 are provided with an introduction portion 78 which is widened toward the end, the front cam pin 85 and the rear The switching operation when the cam engagement of the cam pin 86 is switched can be performed smoothly. Note that the movement when changing from the shooting state to the non-shooting state is the reverse of the above-described operation.

  An automatic exposure apparatus 3 is attached to the front of the second group ring 12 so as to be movable by a predetermined distance in the optical axis direction while restricting movement in the rotation direction. The automatic exposure device 3 is an optical device having a function of a shutter that opens and closes an optical path through which light passes, a function of a variable aperture that changes the diameter of the optical path, and a filter function that moves a filter in and out of the optical path. As shown in FIG. 12, the automatic exposure apparatus 3 includes a ring-shaped hollow holder 88, and a shutter blade, an aperture blade, and a filter blade are placed in three directions of the hole so as to surround the central hole. Has been placed. On the outer surface of the holder 88, three guide projections 89 are provided at equal intervals in the circumferential direction.

  Three projection receiving portions 91 corresponding to the three guide projections 89 of the automatic exposure apparatus 3 are provided in the second group ring 12. By engaging the guide protrusions 89 with the protrusion receiving portions 91, the automatic exposure apparatus 3 can be moved forward and backward in the optical axis direction by the gap in the protrusion receiving portion 91. Further, between the automatic exposure apparatus 3 and the second group ring 12, a plurality of compression coil springs 92 showing a specific example of an elastic member that biases them in the direction of separating them from each other are interposed. The position where the plurality of compression coil springs 92 are most extended and the automatic exposure apparatus 3 is farthest from the second group ring 12 is the position in the photographing state. Conversely, the plurality of compression coil springs 92 are most contracted. Thus, the position where the automatic exposure apparatus 3 is closest to the second group ring 12 is the position in the non-photographing state.

  In the non-photographing state, the boss portion 12c of the second group ring 12 enters the central hole 88a of the holder 88 of the automatic exposure apparatus 3. Therefore, the diameter of the central hole 88a is set larger than the diameter of the boss portion 12c. Furthermore, the front end surface of the boss portion 12 c is configured to penetrate the central hole 88 a and be substantially flush with the front surface of the holder 88. For this reason, in the non-photographing state, the shutter function, variable aperture function, and filter function blades of the automatic exposure device 3 need to be retracted outward from the central hole 88a. In order to ensure such a function, a gap regulating member 94 is interposed between the automatic exposure apparatus 3 and the second group ring 12.

  The interval regulating member 94 has a configuration as shown in FIG. The spacing regulating member 94 includes a ring portion 94a that is rotatably fitted to the boss portion 12c of the second group ring 12, and a lever portion 94b that is formed so as to protrude radially outward from the outer periphery of the ring portion 94a. have. A cam projection 94c extending in a direction perpendicular to the surface direction of the ring portion 94a is provided at the tip of the lever portion 94b. The cam projection 94c protrudes to the opposite side of the automatic exposure device 3 through a hole provided in the second group lens frame 12b in a state in which the interval regulating member 94 is assembled to the second group ring 12. The interval regulating member 94 is constantly urged in a predetermined rotational direction by a torsion spring 95 showing a specific example of the elastic member.

  Further, the ring portion 94a of the interval regulating member 94 is provided with three stopper portions 94d that prevent the automatic exposure apparatus 3 and the second group ring 12 from approaching a predetermined level. The three stopper portions 94d are arranged at substantially equal intervals in the circumferential direction on the surface of the ring portion 94a opposite to the side from which the cam projection 94c projects. When the lens barrel 1 is in front of the non-photographing state, the cam projection 94c of the interval regulating member 94 is in contact with a cam projection 18e that protrudes forward provided on the rear surface portion 18a of the rear barrel 18. From this state, when the lens barrel 1 is further moved in the non-photographing state, the distance regulating member 94 is rotated by a predetermined amount according to the cam surface of the cam projection 94c and the cam surface of the cam projection 18e.

  As a result, the interval restricting member 94 rotates a predetermined amount, so that the three stopper portions 94d are retracted rearward in the optical axis direction. As a result, the automatic exposure apparatus 3 can move in a direction approaching the second group ring 12, so that the automatic exposure apparatus 3 can be housed in the second group ring 12 to shorten the length in the optical axis direction. On the other hand, in the photographing state, the three stopper portions 94d of the interval regulating member 94 are interposed between the automatic exposure apparatus 3 and the second group ring 12. Therefore, the interval between the automatic exposure apparatus 3 and the second group ring 12 can be regulated by the stopper portion 94d, and the interval can be prevented from becoming unnecessarily narrow.

  With such a configuration, even when an inadvertent external force or impact may be applied to the lens barrel 1 in the photographing state, the interval between the automatic exposure device 3 and the second group ring 12 is narrowed to a predetermined value or more. There is nothing. Therefore, it is possible to prevent the automatic exposure apparatus 3 from being pressed against the second group ring 12, thereby protecting the shutter mechanism, variable aperture mechanism, and the like of the automatic exposure apparatus 3. Moreover, the thickness from the second group ring 12 to the automatic exposure device 3 can be made thinner in the non-photographing state than in the photographing state.

  As shown in FIGS. 2 and 3, the first group ring 10 is relatively rotatably attached to the outer periphery of the body portion 15 a of the cam ring 15. As shown in FIGS. 14 and 15 and the like, the first group ring 10 includes a cylindrical body portion 10a into which the body portion 15a is inserted, and an axial end of the cylindrical body portion 10a that is continuously outward in the radial direction. The outer flange portion 10b is expanded, and the inner flange portion 10c is continuous to the front side which is the other end in the axial direction of the cylindrical portion 10a and is expanded radially inward. Furthermore, three brackets 10d projecting rearward in the optical axis direction are provided on the cylindrical body portion 10a of the first group ring 10 at equal intervals in the circumferential direction.

  Each of the three brackets 10d is provided with a guide convex portion 97 protruding outward in the radial direction and a cam pin 98 showing a specific example of a cam follower protruding inward in the radial direction. The guide convex portion 97 and the cam pin 98 are arranged so as to overlap each other at the same position. However, the guide convex portion 97 is integrally formed so as to build up a part of the bracket 10d. It is provided integrally by press-fitting the member. That is, the guide convex portion 97 is formed of a block-like portion extending in the optical axis direction, and the three guide convex portions 97 are slidably engaged with a linear guide groove (described later) of the linear ring 14. .

  The three cam pins 98 are cam followers that are slidably engaged with the three outer cam grooves 65 provided on the outer periphery of the body portion 15 a of the cam ring 15. The cam pin 98 includes a pin head 98a that is slidably contacted with the outer cam groove 65, a fixing portion 98b that is press-fitted into the mounting hole of the bracket 10d, and a flange provided between the fixing portion 98b and the pin head 98a. Part 98c. The flange portion 98c has a role of restricting the press-fitting depth of the fixing portion 98b and holding the protruding amount of the pin head portion 65a at a predetermined value. An operation surface 99 with which the pressing portion 72 of the cam ring 15 is brought into contact is provided on one side surface of the bracket 10d provided with the cam pins 98 and the like. The operation surface 99 is set to an inclination angle corresponding to the inclined surface of the pressing portion 72, and is approximately 45 degrees, for example.

  The first group ring 10 is mounted on the inner circumference of the straight ring 14 so as to be movable only in the optical axis direction while restricting movement in the rotational direction. As shown in FIGS. 2 and 11, the rectilinear ring 14 is provided at one end in the optical axis direction of the cylindrical portion 14 a into which the first group ring 10 is inserted, and is expanded outward in the radial direction. And an outer flange portion 14b. The outer flange portion 14b is provided with three projecting portions 14c that are slidably engaged with the three rectilinear guide grooves 38B, 38B, 38C provided on the inner periphery of the fixed ring 16, respectively. The three protrusions 14c are arranged at positions corresponding to the three rectilinear guide grooves 38B, 38B, 38C.

  Three rectilinear guide grooves 101 are provided on the inner periphery of the cylindrical portion 14a of the rectilinear ring 14 so that the three guide convex portions 97 provided on the outer periphery of the first group ring 10 are slidably engaged. Yes. The three rectilinear guide grooves 101 are arranged at substantially equal intervals in the circumferential direction and extend linearly in the optical axis direction in parallel with each other. Each straight guide groove 101 has an end on the outer flange portion 14b side opened in the end surface of the cylindrical body portion 14a, and an end on the opposite side is interrupted in the middle in the optical axis direction. As a result, the first group ring 10 can be moved in and out on the outer flange portion 14b side with respect to the rectilinear ring 14, but is dead end on the distal end side on the opposite outer flange portion 14b side. Is configured not to fall off.

  On the outer periphery of the rectilinear ring 14, an outer decorative ring 102 for the rectilinear ring 14 for mainly adjusting the appearance of the lens barrel 1 is attached and integrally formed. With the outer decorative ring 102 attached, the rectilinear ring 14 is attached to the inner periphery of the stationary ring 16. A cam ring 15 is attached to the inner periphery of the rectilinear ring 14 attached to the inner periphery of the fixed ring 16.

  That is, three cam pins 98 provided on the inner periphery of the first group ring 10 are slidably engaged with the three outer cam grooves 74 provided on the outer periphery of the cam ring 15. The three guide convex portions 97 provided on the outer periphery of the first group ring 10 are slidably engaged with the three rectilinear guide grooves 101 provided on the inner periphery of the rectilinear ring 14, respectively. Further, the three protrusions 14c protruding from the outer periphery of the rectilinear ring 14 are slidably engaged with the three rectilinear guide grooves 38B, 38B, 38C provided on the inner periphery of the fixed ring 16, respectively. At the same time, the three cam projections 57A to 57C provided on the flange portion 15b of the cam ring 15 are slidable in the three cam grooves 37A, 37B, and 37C provided on the inner periphery of the fixed ring 16, respectively. Is engaged. Further, the two convex pieces 80c of the rectilinear regulating member 80 held by the cam ring 15 are slidably engaged with the two rectilinear guide grooves 38A and 38A provided on the inner periphery of the fixed ring 16, respectively. ing.

  Thus, the linear movement ring 14 and the linear movement restricting member 80 are configured so that the three protrusions 14c of the linear movement ring 14 are engaged with the three cam grooves 37A, 37B, and 37C of the fixed ring 16 and the linear movement restricting member 80 has two. Since the convex pieces 80c are engaged with the two rectilinear guide grooves 38A, 38A of the fixed ring 16, the cam ring 15 moves in the optical axis direction without rotating relative to the fixed ring 16. They move together in the direction of the optical axis for the distance they move. In addition, since the three guide protrusions 97 of the first group ring 10 are engaged with the three rectilinear guide grooves 101 of the rectilinear ring 14, the first group ring 10 depends on the amount of rotation of the cam ring 15. It moves forward and backward in the direction of the optical axis without rotating. The first group ring 10 and the second group ring 12 are urged so as to be attracted to each other in the optical axis direction by a plurality of coil springs 103 showing a specific example of the elastic member.

  The operation of the first ring 10 and the cam ring 15 by the cam mechanism is as follows. As shown in FIGS. 18A, B, 19A, B and 20A, 20B, the state in which the first group ring 10 is completely housed in the cam ring 15 is the non-photographing state of the imaging apparatus. At this time, the rear end side of the outer cam groove 65 of the cam ring 15 is opened, and the cam pin 98 is positioned in the holding portion 73 of the opened cam groove opening 71 in the non-photographing state of the camera. The engagement with the outer cam groove 65 is released. When the cam ring 15 is rotated in the feeding direction from this state, the pressing portion 72 of the cam ring 15 hits the operation surface 99 of the bracket 10d of the first group ring 10, and the inclined operation surface 99 causes the first group ring 10 to move. Pushed up. By the push-up force of the cam ring 15, the first group ring 10 moves in the optical axis direction without rotating with respect to the fixed ring 16.

  Further, when the cam ring 15 is rotated to a position in the feeding direction, the cam pin 98 is engaged with the outer cam groove 65, and when the cam ring 15 is further rotated, the pressing portion 72 of the cam ring 15 and the operation surface 99 of the first group ring 10. The abutting state is released. Thereafter, according to the rotation amount of the cam ring 15, it moves forward and backward in the optical axis direction without rotating with respect to the fixed ring 16 along the cam curve (trajectory) of the outer cam groove 65. At this time, since the open end of the outer cam groove 65 has a divergent shape, the cam pin 98 can be reliably and easily engaged with the outer cam groove 65. Note that the movement when changing from the shooting state to the non-shooting state is the reverse of the above-described operation.

  As shown in FIGS. 2 and 14, the inner flange portion 10 c provided on the inner periphery of the first group ring 10 is provided with a plurality of step-like fixing portions 105 having different heights in the optical axis direction. . The first group lens frame 11 is held and fixed to the first group ring 10 by using a plurality of fixing portions 105 provided on the inner flange portion 10c. The first group lens frame 11 is made of a ring-shaped member fitted to the inner flange portion 10c, and the first lens group 2 made of a combination of a plurality of lenses is held on the inner periphery thereof. On the outer periphery of the first group lens frame 11, a plurality of sets (three sets in the present embodiment) of clamping projections 106 for fixing the first group lens frame 11 to the first group ring 10 are provided at substantially equal intervals in the circumferential direction. Yes.

  Each sandwiching protrusion 106 is a combination of a front protrusion 106a and a rear protrusion 106b provided with a predetermined gap in the front and rear in the optical axis direction, and the front protrusion 106a and the rear protrusion 106b are arranged slightly offset in the circumferential direction. Has been. The first group lens frame 11 is fixed to the first group ring 10 by sandwiching the fixing portion 105 of the inner flange portion 10c from the front and rear by a plurality of sets of holding protrusions 106 having such a configuration. In this fixed state, when the first group lens frame 11 is rotated in the circumferential direction, the first group lens frame 11 is moved forward and backward in the optical axis direction by the amount of the step according to the amount of rotation. Reference numeral 108 shown in FIG. 14 and the like is a decorative ring that covers the periphery of the first lens group 2.

  As shown in FIGS. 2 to 4, a lens barrier unit 110 is provided at the front end of the first group ring 10 to close the optical path that is a photographing aperture and protect the photographing optical system when not photographing. The lens barrier unit 110 includes a ring-shaped barrier body 110a, a pair of opening / closing blades 110b rotatably supported by the barrier body 110a, a blade opening / closing mechanism 110c for opening / closing the opening / closing blade 110b, and the like. It is configured. The barrier body 110a is provided with a plurality of engaging claws 110d at substantially equal intervals in the circumferential direction. The lens barrier unit 110 is fixed to the first group ring 10 by engaging the engaging claws 110d with the inner periphery of the cylindrical portion 10a.

  Although not shown, the blade opening / closing mechanism 110c of the lens barrier unit 110 is provided with a drive arm that rotates the opening / closing blade 110b. The drive arm is configured to rotate by relative movement in the optical axis direction. Therefore, by rotating the drive arm by relative movement in the optical axis direction, the opening / closing blade 110b is opened / closed to open / close the optical path of the lens barrier unit 110.

  As shown in FIGS. 2 to 4, an inner decorative ring 112 for adjusting the appearance of the lens barrel 1 is attached to the first group ring 10. The inner decorative ring 112 has the same function as the outer decorative ring 102 for the straight ring 14 and is attached to the first group ring 10 and fixed integrally therewith. As a material for the inner decorative ring 112 and the outer decorative ring 102, for example, a metal such as an aluminum alloy or stainless steel is suitable, but it goes without saying that an engineering plastic can be used. The material of the first group ring 10, the first group lens frame 11, the second group ring 12, the rectilinear ring 14, the cam ring 15, the fixed ring 16, the third group lens frame 17 and the rear barrel 18 is, for example, fiber reinforced plastic. (FRP) is preferable, but it is possible to use ABS (acrylonitrile butadiene styrene resin) and other engineering plastics, as well as aluminum alloys and other metals.

  As shown in FIGS. 3 and 4, a flexible wiring board 115 is electrically connected to the automatic exposure apparatus 3. One end of the flexible wiring board 115 is connected to a wiring circuit of an actuator that drives a shutter mechanism, a variable aperture mechanism, and the like of the automatic exposure apparatus 3, and the other end is a power source installed outside the lens barrel 1. Electrically connected. One end of the flexible wiring board 115 is swung into the second group ring 12 with an appropriate slack so that no adverse effect is caused by its own reaction force even if the distance between the automatic exposure device 3 and the second group ring 12 changes. Yes.

  As shown in FIGS. 2 and 23 to 25, the CCD unit 20 includes the CCD (charge coupled device) 7 showing a specific example of the imaging device, a CCD adapter 27 to which the CCD 7 is fixed, and the light reception of the CCD 7. A low-pass filter 6 disposed in front of the surface, a bellows 29 that elastically supports the low-pass filter 6 so as to be movable back and forth in the optical axis direction of the lens system, and a filter that partitions an area through which light from the subject passes through the low-pass filter 6 A mask 30 and a filter pressing plate 31 for limiting the amount of movement of the low-pass filter 6 in the direction away from the CCD 7 are provided.

  The CCD 7 includes a thin block-shaped CCD main body 7a having a substantially rectangular shape, and a light receiving portion 7b provided on one plane of the CCD main body 7a, and a stepped edge around the light receiving portion 7b. A portion 7c is provided. The CCD 7 is disposed at the rear end of the lens system composed of a combination of the first lens group 2 to the third lens group 5, and the optical axis of the lens system is set at a substantially central portion of the light receiving portion 7b. ing. When light from the subject is input to the light receiving portion 7b of the CCD 7, the light is photoelectrically converted and output from the CCD 7 as an electrical signal.

  The CCD adapter 27 is made of a frame-like member having an opening 131 for exposing the light receiving surface 7a of the CCD 7. That is, the CCD adapter 27 includes a frame-shaped adapter main body 27a provided with an opening 131, and flange-shaped fixing portions 27b and 27b provided at a plurality of locations (in this embodiment, two locations) on the outer edge of the adapter main body 27a. have. The two fixing portions 27b and 27b are arranged in the diagonal direction of two opposing sides of the adapter main body 27a. Each fixing portion 27b is provided with an insertion hole 132a through which a screw shaft portion of a mounting screw (not shown) is inserted, and a positioning hole 132b for positioning at a predetermined position of the rear barrel 18.

  Further, sliding contact portions 27c that are slidably held by the filter pressing plate 31 are provided on the sides of the adapter main body 27a opposite to the fixing portions 27b where the fixing portions 27b are provided. The flat surface of each sliding contact portion 27c developed in the direction through which the opening 131 passes (the thickness direction of the adapter main body 27a) is a smooth surface. Restricting claws 133 for preventing the CCD 7 from being separated from the CCD 7 by a predetermined distance or more are provided. Each restricting claw 133 is formed with the surface of the CCD 7 parallel to the plane of the adapter main body 27a, and the opposite surface is formed as an inclined surface. I try to make it difficult. As the material of the adapter main body 27a, an engineering plastic having appropriate strength and rigidity is suitable, but an aluminum alloy or other metals can also be used.

  The bellows 29 shows a first specific example of an elastic sealing body which is an advancing / retracting support member that elastically supports the low-pass filter 6 so as to be able to approach and separate from the CCD 7. The bellows 29 is formed of an accordion-shaped telescopic cylindrical body having flexibility and sealing properties, and is formed of, for example, silicon rubber. The cross-sectional shape of the bellows 29 in the direction orthogonal to the expansion / contraction direction is a substantially square shape corresponding to the shape of the light receiving portion 7b of the CCD 7, and does not interfere with the light transmitted through the lens system and irradiated on the light receiving portion 7b. Is set. Further, the cross-sectional shape of the bellows 29 in the expansion / contraction direction is a shape in which the sine curve is continuous, and as shown in FIGS. 3 and 4, the bellows 29 can be easily advanced and retracted within a predetermined interval. ing. The material of the bellows 29 is not limited to silicon rubber, and it is needless to say that, for example, fluorine rubber, acrylic rubber or other rubber can be applied.

  In order to ensure such a forward / backward movement, a large number of fine air holes through which air does not pass but fine air is allowed to pass on the peripheral surface (side surface) of the bellows 29. By providing such a vent hole, it is possible to move forward and backward while ensuring the internal sealing performance. Instead of this ventilation hole, a relatively large hole may be formed, and the hole may be closed with a fiber, fabric, filter, or the like that does not allow fine foreign substances to pass through but allows air to pass through. An end surface portion 29a at one end of the bellows 29 in the expansion / contraction direction is brought into close contact with the outer edge or the edge portion 7c of the light receiving portion 7b of the CCD 7, and is fixed in a liquid-tight manner using an adhering means such as an adhesive. Then, the outer edge of the low-pass filter 6 is brought into close contact with the end surface portion 29b at the other end in the expansion / contraction direction of the bellows 29, and is fixed in a liquid-tight manner by using an adhering means such as an adhesive.

  The low-pass filter 6 is a first specific example of an optical filter and has a size capable of completely closing one end surface portion 29b of the bellows 29. A filter mask 30 is integrally provided on the outer edge of the surface of the low-pass filter 6 opposite to the bellows 29 by a fixing means such as an adhesive. The filter mask 30 limits the range of light that passes through the low-pass filter 6, is formed in a rectangular frame shape, and continuously covers the periphery of the low-pass filter 6. A filter holding plate 31 is disposed outside the filter mask 30.

  The filter presser plate 31 includes a presser plate main body 31a provided with an opening window 135 that allows light from the subject to pass through, and two restricting pieces 31b formed to protrude outward from two opposing sides of the presser plate main body 31a. , 31b and two folded portions 31c, 31c formed so as to protrude outward from the remaining two opposite sides of the presser plate body 31a. The two restricting pieces 31b, 31b are bent 90 degrees from the midway part thereof, and are formed so that the tip part protrudes to one surface side. The two restricting pieces 31b and 31b are set at positions corresponding to the two sliding contact portions 27c and 27c of the CCD adapter 27, and their intervals are also set to be substantially the same. It is made like that.

  Furthermore, the two regulating pieces 31b and 31b of the filter pressing plate 31 are respectively provided with guide grooves 136 extending in a direction through which the opening window 135 passes. Two regulating claws 133 and 133 provided in the CCD adapter 27 are individually engaged with the two guide grooves 136 and 136, respectively. Within the range of the guide groove 136, the filter pressing plate 31 is movable with respect to the CCD adapter 27 in the optical axis direction of the lens system. The two folded portions 31c and 31c are formed to be bent so as to protrude in the same direction as the regulating claw 133.

  In addition, four pressure receiving convex portions 137 projecting to the opposite side to the regulation claw 133 are provided at the four corners of the presser plate main body 31a. The front end surfaces of the four pressure receiving convex portions 137 protrude to the outermost side on one surface of the filter pressing plate 31. When the lens barrel 1 is most retracted in the non-photographing state, the four pressure receiving convex portions 137 have three groups. The lens frame 17 comes into contact. The low-pass filter 6 whose movement is restricted by the filter pressing plate 31 is always urged away from the CCD 7 based on the restoring force by the elasticity of the bellows 29 itself. In this case, an elastic member such as a spring is provided as a separate component in addition to the elasticity of the bellows 29 itself, and the low-pass filter 6 is always urged away from the CCD 7 by the urging force of the elastic member. Also good. As a material of the filter pressing plate 31, for example, a metal such as a stainless steel plate or a steel plate is suitable, but an engineering plastic can also be used.

  The CCD unit 20 including such components is assembled as follows, for example. First, one end surface portion 29a of the bellows 29 is brought into close contact with the surface of the CCD 7 on the light receiving portion 7a side and fixed. Next, the low-pass filter 6 is adhered and fixed to the other end surface portion 29b of the bellows 29 using an adhering means such as an adhesive. Then, the filter mask 30 is fixed to the surface of the low-pass filter 6 opposite to the bellows 29. The filter mask 30 may be fixed before the low-pass filter 6 is fixed to the bellows 29.

  Next, the bellows 29 is inserted into the opening 131 of the CCD adapter 27 from the low-pass filter 6 side, and the surface of the CCD 7 on the light receiving portion 7a side is attached to one surface (back surface) of the CCD adapter 27 using an adhesive or the like. Fix it. Thereafter, the filter pressing plate 31 is inserted from the low-pass filter 6 side and attached to the CCD adapter 27. At this time, the two regulating pieces 31b, 31b of the filter holding plate 31 are opposed to the two sliding contact portions 27c, 27c of the CCD adapter 27, and the inner surface of each regulating piece 31b is slid on the surface of each sliding contact portion 27c. Move. Then, using the elasticity of the restriction piece 31b, the restriction claw 133 is overcome and the two restriction claws 133 and 133 are engaged with the guide grooves 136 and 136 of the two restriction pieces 31b and 31b, respectively.

  Thus, the filter pressing plate 31 is mounted so as to be relatively movable in the thickness direction of the CCD adapter 27 (the direction in which the bellows 29 expands and contracts) within a predetermined range, and the assembly operation of the CCD unit 20 is completed. The predetermined range at this time is a range in which the restricting claw 133 is movable in the guide groove 136. The CCD unit 20 assembled in this way is shown in FIG. 2, FIG. 23 and FIG. Reference numeral 32 shown in FIG. 2 is a flexible wiring board having a wiring circuit electrically connected to the electric circuit of the CCD 7.

  The optical filter disposed on the front surface of the CCD 7 is not limited to the optical low-pass filter 6 of the above-described embodiment. For example, an infrared cut filter, a composite filter in which both filters are combined, or another optical filter. Of course, can be used.

  26 to 28 show another embodiment of the advance / retreat support member. A bellows 140 shown in FIG. 26 shows a second embodiment of an elastic sealing body which is an advance / retreat support member according to the present invention, and is provided with a dustproof filter 141 on a bellows main body 140a. The bellows main body 140a is the same as the bellows 29 of the above-described embodiment, except that a dustproof filter 141 is integrally provided on the outer surface. The point that one end surface portion 140b of the bellows 140 is fixed to the CCD 7 and the low-pass filter 6 is fixed to the other end surface portion 140c is the same as in the above-described embodiment.

  The dustproof filter 141 includes a filter case 142 made of a rectangular cylinder and a filter member 143 provided so as to close the opening of the filter case 142. The filter case 142 is formed as a flat and thin plate-like cylinder corresponding to the folded portion of the bellows main body 140a, and is joined so that one end on the opening side thereof matches the convex portion of the bellows main body 140a. . Corresponding to the hole of the filter case 142, although not shown, a hole is provided in the side surface of the bellows main body 140a, and the inside of the bellows main body 140a communicates with the outside through the hole. The projecting end of the filter case 142 is formed as an inclined surface inclined at an appropriate angle, thereby increasing the area of the opening so that air can be easily taken in and out. The filter member 143 is formed of a member provided with a large number of gaps that do not allow fine foreign substances to pass therethrough but allows air to pass therethrough.

  A seal rubber 150 shown in FIG. 27 shows a third embodiment of the advancing / retracting support member according to the present invention, and is formed of silicon rubber having high elasticity and excellent flexibility. The seal rubber 150 elastically connects the support portion 150a that supports the low-pass filter 6, the fixed portion 150b that is closely fixed to the CCD 7, and the support portion 150a and the fixed portion 150b, so that the low-pass filter 6 advances and retreats. And an elastic portion 150c that allows operation. The support portion 150a is formed of a rectangular frame-like portion that is slightly larger than the low-pass filter 6, and an opening 151 that is slightly smaller than the low-pass filter 6 is provided on the inside thereof. The fixing portion 150b is a portion for fixing the seal rubber 150 in close contact with the CCD 7, and is formed as a rectangular frame-like portion that is slightly larger than the support portion 150a.

  The elastic portion 150c of the seal rubber 150 is formed by continuing a curved portion having a J-shaped cross section in a rectangular frame shape. Based on the elastic deformation of the elastic portion 150c, the low-pass filter 6 fixed to the support portion 150a can be easily advanced and retracted. In this case, the elastic portion 150c is provided with a large number of ventilation holes, and the sealing rubber 150 can be moved back and forth by taking air in and out of the ventilation holes. The seal rubber 150 may be provided with the dustproof filter 141 described above. Moreover, it is good also as a structure which arrange | positions an elastic member inside the support part 150a, and always urges | biases the low-pass filter 6 to the outer side with the spring force of the elastic member. Of course, the material of the seal rubber 150 is not limited to silicon rubber, and butyl rubber and other rubbers can be applied.

  A telescopic device 160 shown in FIG. 28 shows a fourth embodiment of the advance / retreat support member according to the present invention. The telescopic device 160 includes a support frame 161 that supports the low-pass filter 6, a fixed frame 162 that is fixed in close contact with the CCD 7, an elastic member 163 that urges the support frame 161 in a direction away from the CCD 7, and the like. Have. The support frame 161 is made of a rectangular frame-shaped member that is larger than the low-pass filter 6, and an opening 164 that is slightly smaller than the low-pass filter 6 is provided inside the support frame 161. The light of the subject that has passed through the lens system passes through the opening 164.

  Furthermore, the support frame 161 has an inner flange portion 161a that protrudes to the inside of the opening 164, and an outer flange portion 161b that protrudes outward from the outer edge, and the low-pass filter 6 is supported by the inner flange portion 161a. . The outer flange portion 161b is provided on the surface opposite to the inner flange portion 161a, and has a role of preventing the fixed flange 162 from coming off. A dustproof filter 165 is provided on the surface of the support frame 161 on which the low-pass filter 6 is fixed so as to be lined up side by side. The dustproof filter 165 includes three filter members fitted in a plurality of (three in this embodiment) holes provided in the support frame 161. This filter member is formed of a member that does not allow fine foreign substances to pass therethrough but is provided with a large number of gaps that allow air to pass therethrough.

  The fixed frame 162 is a member that slidably supports the support frame 161 and is configured as a rectangular frame that is slightly larger than the support frame 161. The fixed frame 162 has an inner flange portion 162a projecting inside the rectangular opening and an outer flange portion 162b projecting outward from the outer edge. An inner flange portion 162a is provided on one surface side of the fixed frame 162, and an outer flange portion 162b is provided on the other surface side. The outer flange portion 161b of the support frame 161 is opposed to the inner flange portion 162a, and the outer flange portion 161b is engaged with the inner flange portion 162a to prevent the support frame 161 from coming out of the fixed frame 162. .

  The elastic member 163 constantly urges the low-pass filter 6 in a direction away from the CCD 7 via the support frame 161, and is housed in the frame of the fixed frame 162. The elastic member 163 is formed by a plate spring made of a plate-like spring material, and is configured to be able to urge the four corners of the support frame 161 substantially evenly with substantially the same urging force. In other words, the elastic member 163 includes two elastic pieces 163a and 163a provided substantially in parallel and a connecting piece 163b that connects the two elastic pieces 163a and 163a. Both ends of each elastic piece 163a are bent so as to protrude in the same direction, thereby giving elasticity to both ends so that the entire support frame 161 can be urged with substantially equal force. The connecting piece 163b is set at a position biased to one side in the longitudinal direction of each elastic piece 163a, so that the connecting piece 163b does not block light transmitted through the low-pass filter 6.

  FIGS. 16A and B, FIGS. 17A and B, FIGS. 18A and B, FIGS. 19A and B, FIGS. 20A and B, FIGS. 21 and 22A and B show that the lens barrel 1 extends from the lens barrel storage state to the zooming state. It is a figure explaining the form to change. Next, a variation of the lens barrel 1 will be briefly described.

  16 to 20 show that the lens barrel 1 is in the lens barrel storage state. In this state, the three cam pins 98 of the first group ring 10 are located outside the cam groove opening 71 opened on the flange portion 15 b side in the lens barrel storage operation region 66 of the outer cam groove 65 of the cam ring 15. It is stored in the provided holding portion 73. At this time, of the three cam pins 98, the two cam pins 98 are located at the two notches 55a and 55b of the flange portion 15b. On the other hand, the remaining one cam pin 98 is inserted into a through hole 62 provided in the first flange portion 54a, and is exposed on the back side of the flange portion 15b as shown in FIGS. 20A and 20B.

  The forward / backward movement of the first group ring 10 is executed by the cam ring 15 being driven to rotate relative to the first group ring 10 based on the rotation of the drive gear 22 by the reduction gear unit 21. First, the feeding operation of the first group ring 10 will be described. When the cam ring 15 is rotated in the feeding direction, first, the pressing portion 72 provided on the cam ring 15 comes into contact with the inclined operation surface 99 of the bracket 10 d provided on the first group ring 10, and the pressing portion 72 is operated on the operation surface 99. Is pressed in the circumferential direction. At this time, due to the action of the inclined surface of the pressing portion 72 and the inclined surface of the operation surface 99, a force in the optical axis direction is generated on the operation surface 99.

  The cam pin 98 comes into contact with the pressing portion 72 and the operation surface 99 due to the contact between the pressing portion 72 and the operation surface 99, and gradually shifts from the distal end of the bracket 10d to the proximal end side. When the cam pin 98 completely enters the outer cam groove 65, the contact between the pressing portion 72 and the operation surface 99 is changed to the contact between the cam pin 98 and one side surface of the outer cam groove 65. Thereafter, the cam pin 98 is guided to the outer cam groove 65 by the contact between the cam pin 98 and the outer cam groove 65, and the optical zooming operation is executed. The storing operation of the first group ring 10 is performed by the operation to the opposite side of the operations shown in FIGS.

  When the lens barrel 1 having such an operation is zoom-driven from the non-photographing state as shown in FIG. 3 to the photographing state as shown in FIG. 4, the position of the third group lens frame 17 in the non-photographing state is It is determined by the locus of the front inner cam groove 75 and the rear inner cam groove 76 of the cam ring 15. At this time, by retracting the second group ring 12 from before the non-photographing state, the convex portion 12d of the second group ring 12 comes into contact with the front convex portion 56a of the third group lens frame 17. Similarly, by retracting the third group lens frame 17, the four rear convex portions 56 b of the third group lens frame 17 come into contact with the four pressure receiving convex portions 137 of the filter pressing plate 31 of the CCD unit 20.

  At this time, as shown in FIG. 3, a gap S <b> 1 is set between the third lens group 5 held in the third group lens frame 17 and the low pass filter 6 of the CCD unit 20. Does not directly contact the low-pass filter 6. In addition, the filter pressing plate 31 is pressed by the third group lens frame 17 and the bellows 29 is compressed, and the low-pass filter 6 approaches the CCD 7. At this time, a relatively small gap T <b> 1 is set between the low-pass filter 6 and the CCD 7.

  Therefore, the length of the lens barrel 1 in the optical axis direction can be reduced by setting the gap S1 between the third lens group 5 and the low-pass filter 6 to the minimum value until just before the two contact. it can. Further, the position of the low-pass filter 6 in the non-photographing state in the lens system optical axis direction is also determined by the trajectories of the front inner cam groove 75 and the rear inner cam groove 76 of the cam ring 15. Is set to a position where the distance S1 between the low pass filter 6 and the CCD 7 is minimized, the length of the lens barrel 1 in the optical axis direction can be made as small as possible.

  On the other hand, in the shooting state, as shown in FIG. 4, the low-pass filter 30 has a low-pass filter (advancing / retracting support member) 29 itself to which the low-pass filter 6 is fixed. The filter 6 is urged away from the CCD 7 and is largely separated. As a result, the gap S2 between the low-pass filter 6 and the third lens group 5 is larger than the gap S1 during non-shooting (S2> S1). Further, the low-pass filter 6 and the filter holding plate 31 are pressed by the elasticity of the bellows 29, and the low-pass filter 6 moves in a direction away from the CCD 7.

  As a result, a gap T2 larger than the gap T1 in the non-photographing state is set between the low-pass filter 6 and the CCD 7 (T2> T1). Thereby, even if a foreign substance adheres to the surface of the low-pass filter 6, it can be reduced that the foreign substance is reflected in the light receiving unit 7 a of the CCD 7. In addition, the minimum optical aperture can be reduced, and a thin lens barrel having a small optical minimum aperture can be obtained.

  A digital still camera 300 shown in FIGS. 29 to 31 shows a first example of an imaging apparatus configured by using the lens barrel 1 of the present invention described above. The digital still camera 300 uses a semiconductor recording medium as an information recording medium, converts an optical image from a subject into an electrical signal by a CCD (solid-state imaging device), and records the signal on the semiconductor recording medium. It can be displayed on a flat display panel 302 which is a display device such as a liquid crystal display.

  This digital still camera 300 is a camera case in which the lens barrel 1 that takes an image of a subject as light and guides it to a CCD (imaging device) as an imaging means, and the lens barrel 1 and other devices and devices are incorporated. 301, a flat display panel 302 that is a display device including a liquid crystal display that displays an image based on a video signal output from the CCD, and a control that controls the operation of the lens barrel 1, the display of the flat display panel 302, and the like. The apparatus includes a device and a battery power source (not shown).

  The camera case 301 is formed of a horizontally long flat container, and includes a front case 303 and a rear case 304 that are overlapped in the front-rear direction, and a substantially rectangular frame interposed between the front case 303 and the rear case 304. The center case 305 and the like. A ring-shaped decorative ring 306 is attached to the front surface of the front case 303 at a position slightly deviated to one side from the center, and 1 on the front side of the lens barrel 1 is attached to the central hole 307 of the decorative ring 306. The group ring 10 and the like are facing advancing and retreating.

  FIG. 29 shows a non-photographing state (lens barrel storage state) of the lens barrel 1 corresponding to FIG. 1A, and the entire front surface of the lens barrel 1 is substantially flush with the front surface of the front case 303. It is configured as follows. Further, FIG. 30 shows a photographing state (feed-out state) of the lens barrel 1 corresponding to FIG. 1B, and an inner decorative ring 112 that encloses the first group ring 10 and an outer decorative ring 102 that encloses the rectilinear ring 14 are nested. It is paid out in the state.

  A light emitting unit 307 of a flash device and a light emitting / receiving unit 308 of an autofocus mechanism are provided at an oblique upper portion of the lens barrel 1 of the front case 303. Further, on the upper surface of the center case 305, a power button 309, a shutter button 310, a sound collecting hole 311 of a sound collecting device such as a microphone, and the like are provided. In addition, a battery storage portion in which a battery as a power source is detachably stored is provided on one side surface portion of the center case 305, and a battery lid 312 is detachably engaged with the battery storage portion. Yes. A speaker hole 313 for the speaker device is provided on the side surface of the center case 305 opposite to the battery lid 312.

  As shown in FIG. 31, the rear case 304 has a large display window 315, and the flat display panel 302 is attached to the display window 315. The flat display panel 302 has a touch operation function that can be operated by a user touching the display surface. Various operation switches are provided on one side of the flat display panel 302 of the rear case 304. As operation switches, for example, a mode switching switch 316 for selecting a function mode (still image, moving image, reproduction, etc.), an optical zoom operation button 317 for executing a zoom operation, a menu button 318 for selecting various menus, and a screen display are switched. The display switching button 319 and the like can be mentioned, but other direction keys for moving a cursor for selecting a menu, a screen button for switching a screen size, and deleting a screen can also be provided.

  A control device that drives and controls the lens barrel 1, the flat display panel 302, and the like is built in the camera case 301 having such a configuration. The control device is configured, for example, by mounting a predetermined microcomputer, a resistor, a capacitor, or other electronic components on a wiring board.

  FIG. 32 is a block diagram showing a first example of a schematic configuration of a digital still camera 300 including the lens barrel 1 having the configuration and operation as described above. The digital still camera 300 includes a lens barrel 1, a video recording / reproducing circuit unit 330 that plays a central role of a control device, a program memory, a data memory, and the like for driving the video recording / reproducing circuit unit 330. A built-in memory 331 having a RAM, a ROM, and the like, a video signal processing unit 332 that processes captured video and the like into a predetermined signal, a flat display panel 302 that displays the captured video and the like, and an external that expands the storage capacity A memory 333, a lens barrel control unit 334 that drives and controls the lens barrel 1, and the like are provided.

  The video recording / reproducing circuit unit 330 includes, for example, an arithmetic circuit having a microcomputer (CPU). A built-in memory 331, a video signal processing unit 332, a lens barrel control unit 334, a monitor driving unit 335, an amplifier 336, and two interfaces (I / F) 337 and 338 are connected to the video recording / reproducing circuit unit 330. Yes. The video signal processing unit 332 is connected to the CCD 7 attached to the lens barrel 1 via an amplifier 336. A signal processed into a predetermined video signal by the video signal processing unit 332 is input to the video recording / reproducing circuit unit 330.

  The flat display panel 302 is connected to the video recording / reproducing circuit unit 330 via the monitor driving unit 335. A connector 339 is connected to the first interface (I / F) 337, and an external memory 333 can be detachably connected to the connector 339. Further, a connection terminal 340 provided in the camera case 301 is connected to the second interface (I / F) 338. The lens barrel control unit 334 is connected to a lens driving unit 341 that drives and controls the lens barrel 1 and a position sensor 342 that detects a rotation amount of the lens barrel 1 and a movement amount in the optical axis direction. ing.

  Thus, when an image of the subject is input to the lens system of the lens barrel 1 and formed on the imaging surface of the CCD 7, the image signal is input to the video signal processing unit 332 via the amplifier 336. A signal processed by the video signal processing unit 332 into a predetermined video signal is input to the video recording / reproducing circuit unit 330. Accordingly, a signal corresponding to the subject image is output from the video recording / reproducing circuit unit 330 to the monitor driving unit 335, the built-in memory 331, or the external memory 333. As a result, an image corresponding to the image of the subject is displayed on the flat display panel 302 via the monitor driving unit 335, or is recorded as an information signal in the built-in memory 331 or the external memory 333 as necessary.

  The digital still camera 300 having such a configuration can be used as follows, for example. FIG. 29 shows a state in which the optical lens system is closed by closing the open / close spring 10b of the lens barrier unit 110 in the lens barrel 1, that is, a non-photographing state. In this case, the power of the digital still camera 300 is turned off. FIG. 30 shows a state where the open / close spring 10b of the lens barrier unit 110 is opened and the optical lens system is opened, that is, a state where photographing is possible. This photographing enabled state is automatically executed by operating the power button 309 to turn on the power. As a result, the digital still camera 300 changes from the form shown in FIG. 29 to the form shown in FIG.

  When the digital still camera 300 is ready to shoot, the photographic lens is pointed at the subject and the shutter button 310 is pressed, so that the subject can be photographed and the image can be captured. At this time, by operating the optical zoom operation button 317, the focal length is continuously changed according to the operation direction without changing the position of the image point, and the wide (wide angle) screen or the tele (telephoto) screen. Can be obtained.

  As described above, according to the present invention, by changing the distance in the optical axis direction in the lens system between the optical filter (such as a low-pass filter) and the image sensor (CCD) between shooting and non-shooting, It is possible to reduce the appearance of foreign matter adhering to the surface of a low-pass filter or the like on the light receiving portion of the CCD. As a result, the length of the so-called collapsible lens barrel in the optical axis direction (collapse length) can be reduced, and the lens barrel can be made thinner and the optical minimum aperture can be made smaller.

  That is, the present invention is a lens barrel having a plurality of lenses, in the first state during non-shooting in which the plurality of lenses are brought into close contact with each other and during shooting capable of shooting with the plurality of lenses separated from each other. In the lens barrel capable of selecting the second state, an optical filter is provided immediately before the image sensor, and the optical filter is brought close to the image sensor in the first state, and the optical filter in the second state. The present invention relates to a lens barrel that is separated from the image sensor. In the present embodiment, the CCD is described as the image sensor, but the present invention is not limited to this, and for example, a CMOS or other image sensor can be applied.

  The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, an example in which a digital still camera is applied as the imaging device has been described. However, the present invention can also be applied to a digital video camera, a personal computer with a camera, a mobile phone with a camera, and other imaging devices. Furthermore, although an example using a third lens group as an optical lens has been described, it goes without saying that it may be a fourth lens group or more.

FIGS. 1A and 1B show a first embodiment of a lens barrel cam mechanism according to the present invention, in which FIG. 1A is a perspective view of a lens barrel retracted state and FIG. 1B is a perspective view of a lens barrel extended state of the lens barrel, respectively. . It is the perspective view which decomposed | disassembled the lens-barrel shown in FIG. FIG. 2 is a cross-sectional view of the lens barrel shown in FIG. It is sectional drawing of the lens barrel extension state of the lens barrel shown in FIG. FIG. 2 is a perspective view of a stationary ring according to the lens barrel shown in FIG. 1. FIG. 6 is a development view in which the fixed ring shown in FIG. FIG. 7A is a perspective view, FIG. 7B is a front view, and FIG. 7C is a cross-sectional view taken along line XX of FIG. 8A. FIG. 8A is a plan view and FIG. 8B is a bottom view showing the cam ring of FIG. 7. FIG. 9A is a developed view showing the cam groove on the outer peripheral surface, and FIG. 9B is a developed view showing the cam groove on the inner peripheral surface with a broken line. FIG. 3 is a development view in which a rectilinear advance restriction member of the lens barrel shown in FIG. 2 is developed. FIG. 3 is a development view in which a rectilinear ring of the lens barrel shown in FIG. 2 is developed and guide grooves on an inner peripheral surface are represented by broken lines. It is the perspective view which decomposed | disassembled and expressed the automatic exposure apparatus of the lens-barrel shown in FIG. 2, an interval control member, and 2 group ring. FIG. 3 is a development view in which a second group ring of the lens barrel shown in FIG. 2 is developed. FIG. 3 is an exploded perspective view showing a first group ring and a first group lens frame of the lens barrel shown in FIG. 2. FIG. 15 is a development view in which the first group lens frame shown in FIG. FIG. 16A explains the relationship between the assembly of the first group ring and cam ring of the lens barrel shown in FIG. 2 and the drive gear. FIG. 16A shows the cam follower of the first group ring outward from the cam groove opening of the cam ring. FIG. 16B is a half cross-sectional view of a fully moved state. FIG. 17A is a development view in which the first group ring and the cam ring are expanded to show the main part, and FIG. 17B is a diagram illustrating the relationship between the assembly of the first group ring and the cam ring and the drive gear shown in FIG. FIG. 17 is a development view showing a cam groove opening partly by partially cutting a gear part of 17A. FIG. 18A is a front view and FIG. 18B is a bottom view for explaining the relationship between the assembly of the first group ring and the cam ring shown in FIG. 16 and the drive gear. FIG. 19A is a right side view, and FIG. 19B is a cross-sectional view taken along line YY in FIG. 18B, for explaining the relationship between the assembly of the first group ring and cam ring shown in FIG. FIG. 20A is a perspective view seen from the bottom side, and FIG. 20B is an enlarged view of the main part of FIG. 20A. FIG. 16 is a perspective view illustrating a relationship between the assembly of the first group ring and the cam ring and the drive gear shown in FIG. 16 in a state where the cam follower of the first group ring has moved to the lens barrel storage region of the cam groove of the cam ring. It is. FIG. 22A is a half sectional view illustrating the relationship between the assembly of the first group ring and cam ring shown in FIG. 16 and the drive gear, FIG. 22B is a half sectional view, and FIG. FIG. 5 is a development view showing a cam groove opening by sectioning a part of the portion. It is the perspective view which looked at the 2nd group ring of the lens barrel shown in FIG. 2, the 3rd group lens frame, and the CCD unit from the front side. FIG. 3 is a perspective view of a second group ring, a third group lens frame, and a CCD unit of the lens barrel shown in FIG. It is the perspective view which decomposed | disassembled the CCD unit of the lens-barrel shown in FIG. FIG. 5 is an explanatory view of a part of the first embodiment of the advance / retreat support member for the CCD unit of the lens barrel shown in FIG. FIG. 5 is an explanatory view of a part of a second embodiment of the advance / retreat support member according to the CCD unit of the lens barrel shown in FIG. FIG. 10 is an explanatory view of a part of a third embodiment of the advancing / retreating support member according to the CCD unit of the lens barrel shown in FIG. FIG. 2 is a perspective view of a digital still camera showing an example of an imaging apparatus using the lens barrel of FIG. 1 as seen from the front side in a lens barrel storage state. FIG. 2 is a perspective view showing a digital still camera showing an embodiment of an imaging apparatus using the lens barrel of FIG. 1 as seen from the front side in a lens barrel extended state. FIG. 2 is a perspective view of a digital still camera showing an example of an imaging apparatus using the lens barrel of FIG. 1 as viewed from the back side. It is block explanatory drawing showing the schematic structure of the digital still camera which shows the implementation example of the imaging device using the lens-barrel of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lens barrel, 2 ... 1st lens group, 3 ... Automatic exposure apparatus, 4 ... 2nd lens group, 5 ... 3rd lens group, 6 ... Low pass filter (optical filter), 7 ... CCD (imaging element), DESCRIPTION OF SYMBOLS 10 ... 1 group ring (straight advance member), 11 ... 1 group lens frame, 12 ... 2 group ring (straight advance member), 13 ... 2 group lens frame, 14 ... straight advance ring, 15 ... cam ring (rotating member), 16 DESCRIPTION OF SYMBOLS ... Fixed ring, 17 ... 3 group lens frame, 18 ... Rear lens barrel, 20 ... CCD unit, 21 ... Reduction gear unit, 27 ... CCD adapter, 29 ... Bellows (advance support member), 31 ... Filter holding plate, 37A, 37B, 37C ... Cam groove, 38A, 38B, 38C ... Straight guide groove, 57A, 57B, 57C ... Cam projection, 60 ... Gear portion, 65 ... Outer cam groove (cam groove), 66 ... Lens barrel storage operation area, 67 ... zoo , 74 ... Inner cam groove group, 75 ... Front inner circumferential cam groove, 76 ... Rear inner circumferential cam groove, 80 ... Straight running restriction member, 83 ... Straight running guide groove, 84 ... Cam pin, 85 ... Front cam pin, 86 ... Rear cam pin, 89 ... guide protrusion, 94 ... interval regulating member, 97 ... guide projection, 98 ... cam pin (cam follower), 101 ... straight guide groove, 110 ... lens barrier unit, 300 ... digital still camera (imaging device) 301 ... Camera case 302 ... Flat display panel (display device) 309 ... Power button 310 ... Shutter button 334 ... Lens barrel controller

Claims (6)

An image sensor that receives and photoelectrically converts the light of the subject that has passed through the taking lens; and
An optical filter disposed in front of the image sensor;
A lens barrel comprising:
A lens barrel comprising an advancing / retracting support member for supporting the optical filter on the imaging element so that the optical filter can advance and retreat in the optical axis direction of the photographing lens.   The advancing / retreating support member is formed by an elastic member so as to be expandable / contractable, and an elastic sealing body that hermetically seals between the optical filter and the imaging element, and is provided in the elastic sealing body and allows dust to pass therethrough. The lens barrel according to claim 1, further comprising: a filter portion that prevents the elastic sealing body from moving forward and backward while allowing only air to pass therethrough.   3. The lens barrel according to claim 2, wherein the elastic sealing body is made of a bellows formed in a cylindrical shape by a rubber-like elastic body.   The elastic sealing body includes a support portion that supports the optical filter, a fixing portion that is closely fixed to the imaging element, and an elastic connection between the support portion and the fixing portion. The lens barrel according to claim 2, further comprising an elastic portion that allows the advancing and retreating operation of the lens barrel.   The advancing / retreating support member includes a fixed portion that is fixed in close contact with the imaging element, a movable portion that supports the optical filter and that is nested with respect to the fixed portion, and the movable portion or the fixed portion. A filter unit that prevents the passage of dust and allows only the passage of air and allows the movable unit to move back and forth, and a biasing unit that biases the optical filter in a direction away from the image sensor. The lens barrel according to claim 1, further comprising: An imaging device including a lens barrel having an imaging element that receives and photoelectrically converts light of a subject that has passed through a photographing lens, and an optical filter that is disposed in front of the imaging element,
In the lens barrel,
An imaging apparatus comprising: an advance / retreat support member that supports the optical filter so that the optical filter can be advanced and retracted in an optical axis direction of the photographing lens.

Images