JP5476740B2 - Lens barrel and imaging device - Google Patents

Description

  The present invention relates to a lens barrel and an imaging device, and more particularly to a lens barrel that holds a plurality of lenses and an imaging device that includes the lens barrel.

  2. Description of the Related Art Conventionally, a lens barrel of a camera is mounted on an image pickup unit, a fixed tube fixed to the image pickup unit, a cam tube rotating with respect to the fixed tube, and an optical axis by rotation of the cam tube. A plurality of lens groups moving in the direction are provided (for example, see Patent Document 1).

JP 2000-89086 A

  Such a lens barrel has various design restrictions in order to ensure optical performance. In order to ensure optical performance under the restriction, the structure in the lens barrel should be simplified.

  Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide a lens barrel and an imaging apparatus that have a simplified structure.

The lens barrel described in the present specification holds a guide shaft (30A, 30B) slidable in a predetermined axial direction with respect to the reference member (10) and the first lens (L2), and also guides the guide. The first holding member (12) fixed to the shaft and the second lenses (L3 to L5) different from the first lens are held, and the guide is provided via circular through holes (31, 41). A second holding member (13, 14) engaged with the shaft and slidably held in the axial direction along the guide shaft; and the first holding member is engaged via a circumferential groove (32c). The transmission member (32) for transmitting the axial driving force to the first holding member, and the transmission member and the second holding member via cam grooves (20b, 20c, 20d), respectively. Engaging the transmission member and the second holding member in the axial direction. The drive member (20) for applying power and the transmission member are engaged through an interlocking groove (32a) extending in the axial direction, and when performing a focusing operation, the shaft is rotated around the axial direction to change the magnification. An interlocking key (34) whose position around the axial direction is fixed when performing an operation, and the first holding member is fixed to one end of the guide shaft, The second holding member is supported slidably through circular through holes (36a ₁ , 36a ₂ ) of a pair of bearing portions (47a ₁ , 47a ₂ ) provided apart from each other in the axial direction . the through hole is a lens barrel that provided between the pair of bearing portions.

In this case, when performing the focusing operation, the driving member is fixed at a position around the axial direction, and the transmission member is rotated via the interlocking groove when the interlocking key is rotated around the axial direction. Is also rotated about the axial direction, and the transmission member is rotated about the axial direction, whereby the transmission member is driven in the axial direction via the cam groove, and the transmission member is driven in the axial direction. Accordingly, the first holding member is driven in the axial direction via the circumferential groove, and when performing a magnification operation, the transmission member is fixed at a position around the axial direction via the interlocking groove, When the drive member is rotated around the axial direction, the transmission member is driven in the axial direction via the cam groove, and when the transmission member is driven in the axial direction via the circumferential groove Said first holding Wood can be to be driven in the axial direction.
In the lens barrel described in the present specification, the interlocking key is disposed on the outer peripheral side of the driving member, the transmission member is disposed on the outer peripheral side of the driving member, and the interlocking groove is formed. An outer peripheral portion that is disposed on an inner peripheral side of the drive member and an inner peripheral portion that is formed with a cam follower that engages with the cam groove, and the first holding member includes It may be arranged on the inner peripheral side of the peripheral portion.
In the lens barrel described in the present specification, the driving member is disposed on the inner peripheral side of the outer peripheral portion and on the outer peripheral side of the inner peripheral portion, and the transmission member is in the axial direction. And an intermediate portion connected to the outer peripheral portion and the inner peripheral portion, and the outer peripheral portion, the intermediate portion, and the inner peripheral portion are along the axial direction. It can be assumed that they are arranged in a substantially U shape when viewed from the cross section.

  In the lens barrel described in the present specification, a portion (28a) of the first holding member that engages with the transmission member, a portion (32b) of the transmission member that engages with the drive member, At least one of the portions (35, 45) engaged with the drive member of the second holding member may be located in the vicinity of the guide shaft.

Further, in the lens barrel described in the present specification, the driving member is provided on the inner peripheral side of the reference member, and the pair of bearing portions penetrates the driving member from the reference member to the inner peripheral side. It can be provided so that it may protrude . In the lens barrel described in the present specification, the first holding member is fixed to one end of the guide shaft, and the guide shaft is disposed on the other end side in the axial direction from the transmission member. Can be.

Furthermore, in the lens barrel described in the present specification, a distance between the transmission member in the axial direction and the bearing portion on the one end side may be smaller than a distance between the pair of bearing portions .

  The imaging device described in the present specification is an imaging device including the lens barrel (100) and an imaging unit (200) that captures an image connected by the lens barrel.

  The lens barrel and the imaging device described in this specification have an effect that the structure can be simplified.

It is a figure which shows schematically the structure of the camera which concerns on one Embodiment. It is sectional drawing which shows the state which has a lens-barrel in a wide angle end. It is sectional drawing which shows the state in which the lens barrel was zoomed to the telephoto end. FIG. 4A is a view showing the second group lens sliding cylinder and the vicinity thereof, and FIG. 4B is a diagram showing the third and fifth group lens sliding cylinders, the fourth group lens sliding cylinder and the vicinity thereof. It is a figure taken out and shown. 5A is a cross-sectional view taken along the line AA in FIG. 4B, and FIG. 5B is a cross-sectional view taken along the line BB in FIG. 4B. It is a figure for demonstrating the movement operation | movement of each lens at the time of zooming. It is a figure for demonstrating the movement operation | movement of each lens at the time of focusing. It is a figure for demonstrating one of the effect | actions of one Embodiment. It is sectional drawing which shows the state which has the lens-barrel concerning a modification in a wide-angle end. It is sectional drawing which shows the state by which the lens-barrel which concerns on the modification was zoomed to the telephoto end.

  Hereinafter, a camera according to an embodiment and a lens barrel included in the camera will be described in detail with reference to FIGS.

  FIG. 1 schematically shows a camera 500 according to the present embodiment. As shown in FIG. 1, the camera 500 includes an imaging unit 200 and a lens barrel 100.

  The imaging unit 200 includes a housing 210, an optical system including a primary mirror 212, a pentaprism 214, and an eyepiece optical system 216 housed in the housing 210, a focus detection device 230, a shutter 234, and an image sensor 238. And a main LCD 240 and a main control unit 250.

  In the state of FIG. 1, the main mirror 212 guides most of the incident light incident from the lens barrel 100 to a focusing screen 222 disposed above. The focusing screen 222 is disposed at a focus position of the optical system in the lens barrel 100 and forms an image formed by the optical system in the lens barrel 100.

  The pentaprism 214 reflects the image formed on the focusing screen 222 and then guides it to the eyepiece optical system 216 via the half mirror 224. Thereby, the eyepiece optical system 216 can observe the image on the focusing screen 222 as a normal image. In this case, the half mirror 224 superimposes a display image formed on the finder LCD 226 indicating the shooting conditions, setting conditions, and the like on the image of the focusing screen 222. Accordingly, at the exit end of the eyepiece optical system 216, it is possible to observe a state in which the image on the focusing screen 222 and the image on the viewfinder LCD 226 are superimposed. A part of the light emitted from the pentaprism 214 is guided to the photometry unit 228, and the photometry unit 228 measures the intensity of the incident light, its distribution, and the like.

  The focus detection device 230 uses the light transmitted through the primary mirror 212 and reflected by the secondary mirror 232 provided on the back side of the primary mirror 212 to adjust the focus of the optical system in the lens barrel 100 ( Detect focus state. Note that the primary mirror 212 and the secondary mirror 232 are raised to a position indicated by a broken line in FIG. 1 so as to be retracted from the optical path of incident light incident from the lens barrel 100 at the time of photographing.

  The shutter 234 is disposed behind the primary mirror 212 (behind the optical path of incident light incident from the lens barrel 100), and performs an opening operation in conjunction with the ascending operation of the primary mirror 212 and the secondary mirror 232 at the time of shooting. Do. In a state where the shutter 234 is opened, incident light from the lens barrel 100 enters the image sensor 238 via the optical filter 236. The image sensor 238 converts an image formed by incident light into an electrical signal.

  The main LCD 240 has a display screen portion exposed to the outside of the housing 210. On the display screen of the main LCD 240, various setting information and the like in the imaging unit 200 are displayed in addition to the video (captured video) formed on the imaging device 238.

  The main control unit 250 comprehensively controls various operations of the respective units. The main control unit 250 drives the optical system (lenses L1 to L5) in the lens barrel 100 with reference to information on the focus adjustment state of the optical system detected by the focus detection device 230 in the imaging unit 200. (Autofocus), referring to the amount of operation of the optical system in the lens barrel 100, the fact that it is in focus is displayed on the finder LCD 226 (focus aid).

  Next, the configuration of the lens barrel 100 will be described in detail with reference to FIGS.

  2 and 3 are cross-sectional views of the lens barrel 100. FIG. Among these, FIG. 2 shows a state in which the lens barrel 100 is at the wide-angle end, and FIG. 3 shows a state in which the lens barrel 100 is zoomed to the telephoto end. As shown in these drawings, the lens barrel 100 includes a first group lens L1, a second group lens L2, a third group lens L3, a fourth group lens L4, and a fifth group lens L5 arranged on a common optical axis AX. . In the following description, the first group lens L1 side in the optical axis AX direction will be described as the front side, and the fifth group lens L5 side as the rear side.

  As shown in FIGS. 2 and 3, the lens barrel 100 includes a fixed barrel 10, a first group lens sliding cylinder 11 that holds the first group lens L1, and a second group lens sliding cylinder that holds the second group lens L2. 12, a third and fifth group lens sliding cylinder 13 holding the third group lens L3 and the fifth group lens L5, and a fourth group lens sliding cylinder 14 holding the fourth group lens L4.

The fixed cylinder 10 is fixed to the imaging unit 200 at the base 10a. In this fixed state, the fixed cylinder 10, that is, the lens barrel 100 is in contact with the imaging unit 200 by the end surface 10 b of the fixed cylinder 10 on the imaging unit 200 side being in close contact with the imaging unit 200 (the casing 210 in FIG. Positioned. Protrusions 47 a ₁ and 47 a ₂ are provided on the upper part (ceiling part) of the inner peripheral surface of the fixed cylinder 10. These projections 47a _1, 47a _2, circular through-holes 36a ₁ penetrating in the direction of the optical axis AX, 36a ₂ are formed. Protrusions 47b ₁ and 47b ₂ are provided on the lower part of the inner peripheral surface of the fixed cylinder 10. Through holes 36b ₁ and 36b ₂ penetrating in the optical axis AX direction are formed in the protrusions 47b ₁ and 47b ₂ . The through holes 36b ₁ and 36b ₂ are oblong holes that are long in the vertical direction.

  The first group lens sliding cylinder 11 is connected to a zoom drive cylinder 16 provided inside the first group lens sliding cylinder 11 so as to be interlocked. Specifically, the cam pin 15 implanted in the first group lens sliding cylinder 11 is engaged with a cam groove 16 a formed in the zoom drive cylinder 16.

  On the other hand, the zoom drive cylinder 16 is connected to a zoom operation ring 18 that can freely rotate around the optical axis AX at the outermost periphery of the lens barrel 100. Specifically, a driving force transmission pin 19 projecting outward from the zoom driving cylinder 16 is engaged with an operation groove 18 a parallel to the optical axis AX formed on the inner surface of the zoom operation ring 18. Thereby, the zoom drive cylinder 16 rotates in conjunction with the rotation of the zoom operation ring 18. The zoom operation ring 18 cannot be moved in the front-rear direction, and an anti-slip rubber layer is provided on the outer peripheral surface thereof. The zoom operation ring 18 is rotated by the user during zooming.

  The zoom drive cylinder 16 is rotatable with respect to the zoom guide cylinder 22 provided on the inside thereof. As shown in the lower half of FIGS. 2 and 3, the zoom guide tube 22 is formed with a clearance groove 22 a, and the zoom guide tube 22 and the straight advance groove 16 b formed through the zoom drive tube 16. The rotary connecting member 21 fixed to the cam ring 20 provided on the inner side of the fixed cylinder 10 is engaged. The cam ring 20 is formed with a cam groove 20e that engages with a cam pin 10d protruding from the inside of the fixed cylinder 10.

  According to the above structure, when the zoom operation ring 18 is rotated, the zoom driving cylinder 16 is rotated by the action of the driving force transmission pin 19, and the first group lens sliding cylinder 11 is moved in the front-rear direction by the action of the rotation and cam pin 15. It moves in the direction along the optical axis AX. Further, when the zoom driving cylinder 16 is rotated by the rotation of the zoom operation ring 18, this rotational force is transmitted to the cam ring 20 via the rotary connecting member 21, so that the cam ring 20 moves in the front-rear direction while rotating. The zoom guide tube 22 moves in the front-rear direction together with the zoom drive tube 16 without rotating.

  A cover cylinder 17 is provided between the zoom operation ring 18 and the first group lens sliding cylinder 11. As shown in FIGS. 2 and 3, the cover cylinder 17 moves in the front-rear direction in accordance with the first group lens sliding cylinder 11, and seals between the zoom operation ring 18 and the first group lens sliding cylinder 11. It stops and prevents intrusion of dust into the lens barrel 100.

  FIG. 4A is a diagram showing the second group lens sliding cylinder 12 and the vicinity thereof. As shown in FIG. 4A, the second group lens sliding cylinder 12 includes a holding cylinder 24 that holds the second group lens L2, a pressing ring 26 that is fixed to the holding cylinder 24, and an outer periphery of the holding cylinder 24. And an engaging cylinder 28 provided in a surrounding state. The holding cylinder 24 and the pressing ring 26 are fixed by screwing or the like, and sandwich the outer edge portion of the second group lens L2.

The engagement cylinder 28 cantileverly supports the two guide bars 30A and 30B. The guide bars 30A and 30B are arranged at symmetrical positions with respect to the optical axis AX. The outer diameter of the guide bar 30A substantially coincides with the inner diameters of the through holes 36a ₁ and 36a ₂ formed in the protrusions 47a ₁ and 47a ₂ of the fixed cylinder 10. As shown in FIGS. 2 and 3, the guide bar 30 </ b> A is slidably supported by the protrusions 47 a ₁ and 47 a ₂ of the fixed cylinder 10 while being inserted into the through holes 36 a ₁ and 36 a ₂ . The guide bar 30B is inserted into each of the through holes 36b ₁ and 36b ₂ . In this case, as described above, since the through holes 36b ₁ and 36b ₂ are oblong holes that are long in the vertical direction, the gap between the through holes 36b ₁ and 36b ₂ and the guide bar 30B (the upper side of the guide bar 30B) Further, a slight gap is secured on the lower side. As described above, by securing a gap between the through holes 36b ₁ and 36b ₂ and the guide bar 30B, even if a slight manufacturing error (backlash) occurs in the interval between the guide bars 30A and 30B, the assembly is performed without any problem. be able to.

  As the material of the guide bars 30A and 30B, a high-strength and light-weight material, such as stainless steel, can be used. Between the engagement tube 28 and the guide bars 30A and 30B, a process such as adhesion or press-fitting is performed. It is fixed through.

  Returning to FIG. 4A, a protruding follower 28 a is formed on a part of the outer peripheral surface of the engagement cylinder 28. The follower 28a is engaged with a circumferential groove 32c of an interlocking ring 32 provided outside the engagement cylinder 28. The follower 28a is disposed in the vicinity of the guide bar 30A, that is, in the vicinity of an extension shaft obtained by extending the central axis of the guide bar 30A.

  The interlocking ring 32 in which the circumferential groove 32c is formed further includes an interlocking groove 32a and a cam follower 32b. One end of an interlocking key 34 having a substantially L-shape is engaged with the interlocking groove 32a. The interlocking key 34 is connected to a focus ring 37 provided on the outer peripheral portion of the fixed cylinder 10 shown in FIGS. 2 and 3, and the optical axis AX is rotated along with the rotation of the focus ring 37 around the optical axis AX. It moves in the rotation direction around the center. Thus, when the interlocking key 34 moves in the rotation direction around the optical axis AX, the interlocking ring 32 rotates around the optical axis AX. The interlock key 34 is also connected to a motor 38 provided in the motor chamber 10 c of the fixed cylinder 10. Therefore, the interlocking ring 32 also rotates around the optical axis AX by the movement of the interlocking key 34 in the rotational direction around the optical axis AX accompanying the rotational operation of the motor 38.

The cam follower 32b is engaged with a cam groove 20b formed in the cam ring 20, as shown in FIGS. Therefore, when the interlocking ring 32 rotates, the interlocking ring 32 and members connected to the interlocking ring 32 (the second group lens sliding cylinder 12, the guide bars 30A and 30B, the second group lens L2) are connected to the cam groove 20b and the cam follower. By the action of 32b, it moves in the front-back direction. In this movement in the front-rear direction, the interlocking ring 32 moves in the front-rear direction while rotating around the optical axis AX, but the movement directions of the guide bars 30A, 30B are the through holes 36a ₁ , 36a ₂ and 36b ₁ , 36b _2. Therefore, the second group lens sliding cylinder 12 and the second group lens L2 connected to the guide bars 30A and 30B move in the front-rear direction without rotating. The cam follower 32b is disposed in the vicinity of the guide bar 30A, that is, in the vicinity of an extension shaft obtained by extending the central axis of the guide bar 30A.

  FIG. 4B is a view showing the third and fifth group lens sliding cylinders 13, the fourth group lens sliding cylinder 14, and the vicinity thereof. As shown in FIG. 4B, the third and fifth group lens sliding cylinders 13 hold the third group lens L3 and the fifth group lens L5 at a predetermined interval in the optical axis AX direction. The third and fifth group lens sliding cylinder 13 has two engaging portions 13a and 13b that engage with the guide bar 30A and one engaging portion 13c that engages with the guide bar 30B.

  The engaging part 13b (and 13a) has the circular through-hole 31, as shown to Fig.5 (a) which is the sectional view on the AA line of FIG.4 (b). The through hole 31 has substantially the same diameter as the guide bar 30A, and the weight of the third and fifth group lens sliding cylinder 13 is supported by the guide bar 30A in a state where the guide bar 30A is inserted into the through hole 31. . Here, “substantially the same diameter” means a dimension such that a gap that does not hinder the sliding of the third and fifth group lens sliding cylinders 13 is formed between the guide bar 30 </ b> A and the through hole 31. On the other hand, the engaging portion 13 c has a U-shaped groove 33. The width of the U-shaped groove 33 is set to a dimension that is substantially the same as the diameter of the guide bar 30B, that is, a gap that does not hinder the sliding of the third and fifth group lens sliding cylinders 13. In the third and fifth group lens sliding cylinders 13, the U-shaped groove 33 is engaged with the guide bar 30B, so that the movement in the rotation direction around the guide bar 30A is suppressed. In addition, instead of the U-shaped groove 33, an elongated circular hole that is long in the vertical direction may be formed in the engaging portion 13c.

  Further, as shown in FIG. 5A, a cam follower 35 protrudes from a part of the outer peripheral portion of the third and fifth group lens sliding cylinder 13. The cam follower 35 is engaged with a cam groove 20 c formed in the cam ring 20. For this reason, when the cam ring 20 rotates around the optical axis AX, the third and fifth group lens sliding cylinders 13 receive a driving force in the front-rear direction (optical axis AX direction) in conjunction with the rotation operation. Since the third and fifth group lens sliding cylinders 13 are engaged with the guide bars 30A and 30B as described above, they move only in the front-rear direction without rotating around the optical axis AX. In FIG. 4B and FIG. 2 and the like, illustration of the cam follower 35 and the cam groove 20c is omitted for convenience of illustration.

  As shown in FIGS. 4B and 5A, an upper opening 13d is formed in the upper part of the third and fifth group lens sliding cylinder 13, and a lower opening 13e is formed in the lower part. Yes.

  As shown in FIG. 4 (b), the fourth group lens sliding cylinder 14 is provided in the internal space of the third and fifth group lens sliding cylinder 13, and its upper end is the upper part of the third and fifth group lens sliding cylinder 13. It is exposed from the opening 13d, and its lower end is exposed from the lower opening 13e of the third and fifth group lens sliding cylinder 13. Engaging portions 14a and 14b that engage with the guide bar 30A are provided at the upper end portion of the fourth group lens sliding cylinder 14, and an engaging portion 14c that is engaged with the guide bar 30B is provided at the lower end portion. Yes.

  The engaging portion 14a (and 14b) has a circular through hole 41 as shown in FIG. 5B, which is a cross-sectional view taken along the line BB of FIG. 4B. The through hole 41 has substantially the same diameter as that of the guide bar 30A, that is, a diameter that forms a gap that does not hinder the sliding of the fourth group lens sliding cylinder 14, and the guide bar 30A is inserted into the through hole 41. In this state, the weight of the fourth group lens sliding cylinder 14 is supported. On the other hand, the engaging portion 14c has a U-shaped groove 43 as shown in FIG. The width of the U-shaped groove 43 is set to a dimension that is substantially the same as the diameter of the guide bar 30B, that is, a gap that does not interfere with the sliding of the fourth group lens sliding cylinder 14. In the fourth group lens sliding cylinder 14, the U-shaped groove 43 is engaged with the guide bar 30 </ b> B, so that the movement in the rotation direction around the guide bar 30 </ b> A is suppressed. In addition, instead of the U-shaped groove 43, a long oval hole that is long in the vertical direction may be formed in the engaging portion 14c.

  Further, as shown in FIG. 5 (b), a cam follower 45 projects from a part of the outer peripheral portion of the fourth group lens sliding cylinder 14. Since the cam follower 45 is engaged with a cam groove 20d (see FIG. 5A) formed in the cam ring 20, when the cam ring 20 rotates around the optical axis AX, It moves in the direction (optical axis AX direction). In this case, since the fourth group lens sliding cylinder 14 is engaged with the guide bars 30A and 30B, it moves only in the front-rear direction without rotating. In FIG. 4B and FIG. 2 and the like, illustration of the cam follower 45 and the cam groove 20d is omitted for convenience of illustration.

  Here, as shown in FIG. 5A, the cam followers 35 and 45 are disposed in the vicinity of the guide bar 30A. Here, the vicinity of the guide bar 30A means, for example, a range of about 0 ° to 45 °. Thus, by arranging the cam followers 35 and 45 in the vicinity of the guide bar 30A, the force (driving force in the front-rear direction) from the cam followers 35 and 45 acts on the vicinity of the guide bar 30A. Therefore, efficient movement of the sliding cylinders 13 and 14 can be realized. If there is no design restriction, the cam followers 35 and 45 are preferably located in the vicinity of the guide bar 30A.

  Next, based on FIGS. 6 and 7, the moving operation of the second lens unit L2 to the fifth lens unit L5 when performing the zoom operation (zooming) and the second lens unit L2 to the fifth lens unit when focusing (focusing) The movement operation of the lens L5 will be described. In FIGS. 6 and 7, illustration of portions related to the operation of the first lens unit L <b> 1 is omitted in order to avoid complication of the drawings.

  First, the movement operation of each lens during zooming will be described with reference to FIGS. 6 (a) and 6 (b). Here, the operation from the state in which the lens barrel 100 is at the wide-angle end (FIG. 6A) to the zooming to the telephoto end (FIG. 6B) will be described.

  When the zoom operation ring 18 (see FIG. 2 and the like) is rotated by the user from the state of FIG. 6A, the cam ring 20 is rotated through the rotary connecting member 21 and the like as described above. Along with this rotation, the rotational force and the forward moving force also act on the interlocking ring 32 via the cam follower 32b. The interlocking ring 32 is operated by the interlocking key 34 (fixed state) that engages with the interlocking groove 32a. Since it is guided only in the front-rear direction, it goes straight ahead without rotating. As the interlocking ring 32 moves straight, the engagement cylinder 28 (that is, the second group lens sliding cylinder 12) and the second group lens L2 that engage with the interlocking ring 32 move in the forward direction.

  Further, the rotation of the cam ring 20 is caused by the forward movement of the third and fifth group lens sliding cylinders 13 and the fourth group lens sliding cylinder 14 (3 to 5 group lenses L3 to L5) engaged via the cam followers 35 and 45. Move to. The moving distance between the lenses L3 and L5 and the lens L4 varies depending on the formation direction (angle) of the cam grooves 20c and 20d with which the cam follower 35 and the cam follower 45 are engaged. Since the cam ring 20 itself moves in the forward direction, the actual moving distance of each of the lenses L3 to L5 is the total distance of the moving distance of the cam ring 20 and the moving distance of the cam followers 35 and 45 by the cam grooves 20c and 20d. Become.

  As described above, during zooming, each of the second to fifth group lenses L2 to L5 (and the first group lens L1 which is not illustrated and illustrated) is separately moved forward in accordance with the rotation operation of the zoom operation ring 18. (However, the lenses L3 and L5 have the same distance).

  Next, the movement operation of each lens at the time of focusing will be described with reference to FIGS. 7 (a) and 7 (b). Here, it is assumed that focusing is performed from the state shown in FIG. 7A and the state shown in FIG.

  First, when the focus ring 37 is rotated by the user or the motor 38 is driven to rotate, the interlock key 34 moves in the rotation direction around the optical axis AX, as described above, the interlock key 34 The interlocking ring 32 to be engaged rotates around the optical axis AX. By this rotation, the interlocking ring 32 moves in the forward direction along the cam follower 32 b along the cam groove 20 b of the cam ring 20. Then, by the movement of the interlocking ring 32 in the rotational direction and the forward direction, the engaging cylinder 28 (that is, the second lens group sliding cylinder 12) having the follower 28a engaged with the circumferential groove 32c of the interlocking ring 32 and the second lens group L2 Will also move forward. Here, since the cam follower 32b and the follower 28a are disposed in the vicinity of the guide bar 30A, the driving force in the optical axis AX direction can be efficiently applied to the interlocking ring 32 and the engagement cylinder 28.

  On the other hand, since the cam ring 20 is in a non-rotating fixed state, the third to fifth lens groups L3 to L5 do not move in the front (rear) direction. Further, the first group lens L1, which is not described and illustrated, does not move in the front (rear) direction.

  In this way, during focusing, only the second group lens L2 moves in the front (rear) direction as the interlocking key 34 rotates.

  Note that the rotation of the motor 38 during focusing is controlled by the main control unit 250 in FIG. 1 based on the detection result of the focus detection device 230. That is, autofocus is executed by the rotation control of the motor 38 by the main control unit 250. Note that the lens barrel 100 and the imaging unit 200 are electrically connected by a connection terminal provided between the lens barrel 100 and the imaging unit 200, and thereby, the lens barrel 100 (for example, Electric power is supplied to the motor 38 and the like from the imaging unit 200 side.

  As described above, according to the present embodiment, the second group lens sliding cylinder 12 that holds the second group lens L2 is fixed to the guide bars 30A and 30B that can slide in the optical axis AX direction with respect to the fixed cylinder 10. The third and fifth group lens sliding cylinders 13 holding the third group lens L3 and the fifth group lens L5, and the fourth group lens sliding cylinder 14 holding the fourth group lens L4 are arranged along the guide bars 30A and 30B along the optical axis. Since it is held so as to be slidable in the AX direction, it is not necessary to provide a guide bar for each lens sliding cylinder, and the structure inside the lens barrel 100 can be simplified. Further, the driving force in the optical axis AX direction is transmitted from the interlocking ring 32 to the second group lens sliding cylinder 12, and the interlocking ring 32, the third and fifth group lens sliding cylinders 13, and the fourth group lens sliding cylinder 14 are transmitted to the second group lens sliding cylinder 12. Since a driving force in the direction of the optical axis AX is applied from the cam ring 20, a rotational force or the like is applied to the cam ring 20, so that the interlocking ring 32 (and the second group lens sliding cylinder engaged therewith) can be provided. 12), the third and fifth group lens sliding cylinders 13 and the fourth group lens sliding cylinder 14 can be simultaneously driven in the direction of the optical axis AX, and by applying a rotational force or the like to the interlocking ring 32, 2 Only the group lens sliding cylinder 12 can be driven in the optical axis AX direction. This makes it possible to realize different operations of the plurality of lenses according to the situation (during zooming, focusing, etc.) with a simple configuration.

  In this embodiment, since the cam follower 32b, the follower 28a, and the cam followers 35 and 45 are provided in the vicinity of the guide bar 30A, the interlocking ring 32, the second group lens slide cylinder 12, the third group lens slide, and the fifth group lens slide are provided. The movement (driving) of the cylinder 13 and the fourth group lens sliding cylinder 14 can be performed efficiently.

In the present embodiment, the guide bar 30A is slidably supported by a pair of protrusions 47a ₁ and 47a ₂ provided on the fixed cylinder 10 so as to be separated from each other in the optical axis AX direction. The moving cylinder 13 and the fourth group lens sliding cylinder 14 are provided between the pair of protrusions 47a ₁ and 47a ₂ . Here, as shown in FIG. 8, and the guide bars 30A, when the gap exists between the through hole 36a ₂ of the protrusion 47a ₁ of the through-holes 36a ₁ and the projections 47a _2, guide bars 30A are, The projections 47a ₁ and 47a ₂ are held in contact with only the points 77a and 77b shown in FIG. Even in such a case, the tilt amount (tilt angle α) of the guide bar 30A from the optical axis AX direction can be reduced by increasing the distance between the protrusions 47a ₁ and 47a ₂ . Thus, in the present embodiment, the tilt amount of the second group lens L2 can be reduced, so that the optical performance of the lens barrel 100 ′ can be improved.

  In the above-described embodiment, the case where the interlocking ring 32 is ring-shaped has been described. However, the present invention is not limited to this, and only the part (part of the ring) that can exhibit the function of the interlocking ring 32 is left, and the others. May be omitted.

  In the above-described embodiment, the case where the cam follower 32b, the follower 28a, and the cam followers 35 and 45 are disposed in the vicinity of the guide bar 30A has been described. However, the present invention is not limited thereto, and at least one of them is the guide bar 30A. It may be arranged only in the vicinity.

  As the lens barrel, a structure (lens barrel 100 ′) as shown in FIGS. 9 and 10 can be adopted. FIG. 9 is a sectional view showing a state where the lens barrel 100 ′ is at the wide-angle end, and FIG. 10 is a sectional view showing a state where the lens barrel 100 ′ is zoomed to the telephoto end. As shown in FIGS. 9 and 10, in the lens barrel 100 ′, the engagement cylinder 28 constituting the second group lens sliding cylinder 12 has a cam follower 28 a ′, and the cam follower 28 a ′ is a cam groove of the cam ring 20. It has the structure directly engaged with 20b.

  Even if such a configuration is adopted, when the user rotates the zoom operation ring 18 during zooming, the cam ring 20 rotates around the optical axis AX by the rotation as in the above embodiment. Interlocked movement of the second group lens sliding cylinder 12 (second group lens L2), and the third and fifth group lens sliding cylinder 13 and the fourth group lens sliding cylinder 14 (3 to 5 group lenses L3 to L5) Can be realized. This modification assumes the case where the second group lens is dedicated to zooming. Therefore, focusing is performed by a lens different from the second group lens.

  In the above embodiment (FIGS. 1 to 8), all of the first to fifth group lenses L1 to L5 move in the optical axis AX direction during zooming, and only the second group lens L2 moves during focusing. Although the case of moving in the optical axis AX direction (inner focus type) has been described, the present invention is not limited to this. For example, at the time of focusing, any of the lenses L1, L3 to L5 other than the second group lens L2 may be moved in the optical axis AX direction. Among these methods, the method of performing focusing by moving the first group lens L1 is called a front lens payout method. Further, at the time of focusing, all the lenses of the first to fifth group lenses L1 to L5 or a plurality of these lenses may be moved. Among these, the method in which all the lenses are moved is called an entire extension method.

In the above-described embodiment, the case where the through holes 36b ₁ and 36b ₂ are oblong holes that are long in the vertical direction has been described to cope with an error (backlash) between the guide bars 30A and 30B. It is not limited to. For example, the inner diameters of the through holes 36b ₁ and 36b ₂ may be set to be slightly larger than the through holes 36a ₁ and 36a ₂ . Alternatively, or in addition to this, the outer diameter of the guide bar 30B may be made smaller than the outer diameter of the guide bar 30A to cope with an error (backlash) between the guide bars 30A and 30B. . Further, instead of the through-hole 36b _1, 36b ₂ having a long oval shape in the vertical direction, may be provided a U-shaped groove.

  In the above embodiment, the case where the third lens group L3 and the fifth lens group L5 are held by the common lens sliding cylinder 13 is described. However, the present invention is not limited to this, and the third lens group L3 and the fifth lens group L5 are Alternatively, they may be held by separate lens sliding cylinders.

  In addition, the number of lenses and the lens arrangement in the above embodiment are examples. In other words, the lens barrel has at least a lens held by one lens sliding cylinder fixed to the guide bar and a lens held by another lens sliding cylinder that slides along the guide bar. If you do.

  In the above-described embodiment, a member provided with a convex member (part) such as a cam follower or a follower is provided with a concave part such as a cam groove or a circumferential groove instead of the convex member (part). In addition, a member provided with a concave portion such as a cam groove or a circumferential groove may be provided with a convex member (portion) such as a cam follower or a follower instead of the concave portion.

  The above-described embodiment is an example of a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Fixed cylinder 12 2 group lens sliding cylinder 13 3, 5 group lens sliding cylinder 14 4 group lens sliding cylinder 20 Cam ring 20b-20e Cam groove 28a Follower 30A, 30B Guide bar 32 Interlocking ring 32b Cam follower 32c Circumferential groove 35 Cam follower 45 Cam follower L2 2nd group lens L3 3rd group lens L4 4th group lens L5 5th group lens 100 Lens barrel 200 Imaging unit 500 Camera

Claims (9)

A guide shaft that is slidable in a predetermined axial direction with respect to a reference member, a first holding member that holds the first lens and is fixed to the guide shaft, and a second that is different from the first lens A second holding member that holds the lens, engages with the guide shaft through a circular through hole, and is slidable in the axial direction along the guide shaft; and the first holding member Is engaged through a circumferential groove, and a transmission member that transmits the axial driving force to the first holding member, and _the transmission member and the second holding member are engaged through a cam groove, respectively. And a driving member that applies a driving force in the axial direction to the transmission member and the second holding member, respectively.
The transmission member is engaged through an interlocking groove extending in the axial direction, and is rotated around the axial direction when performing a focusing operation, and fixed around the axial direction when performing a zooming operation. and an interlocking key that is,
The first holding member is fixed to one end of the guide shaft,
The guide shaft is supported so as to be slidable through a circular through hole of a pair of bearing portions provided apart in the axial direction,
The lens barrel , wherein the through hole of the second holding member is provided between the pair of bearing portions . When performing the focusing operation, the driving member is fixed at a position around the axial direction, and the transmission member is also moved through the interlocking groove when the interlocking key is rotated around the axial direction. When the transmission member is rotated about the axial direction, the transmission member is driven in the axial direction via the cam groove, and when the transmission member is driven in the axial direction, the transmission member is rotated in the axial direction. The first holding member is driven in the axial direction via a circumferential groove,
When performing a zooming operation, the transmission member is fixed at a position around the axial direction via the interlocking groove, and the transmission member is rotated via the cam groove by rotating the drive member around the axial direction. claims are _{sandwiching member} moving drive in the axial direction, the through the circumferential groove by the transmission member is driven in the axial direction first Hozai is characterized to be driven in the axial direction The lens barrel according to Item 1. The interlocking key is disposed on the outer peripheral side of the driving member,
The transmission member is disposed on the outer peripheral side of the drive member and has an outer peripheral portion where the interlocking groove is formed, and a cam follower which is disposed on the inner peripheral side of the drive member and engages with the cam groove. And an inner periphery that is
The lens barrel according to claim 1, wherein the first holding member is disposed on an inner peripheral side of the inner peripheral portion. The driving member is disposed on the inner peripheral side of the outer peripheral part and on the outer peripheral side of the inner peripheral part,
The transmission member extends in a direction substantially orthogonal to the axial direction, and has an intermediate portion connected to the outer peripheral portion and the inner peripheral portion,
The lens barrel according to claim 3, wherein the outer peripheral portion, the intermediate portion, and the inner peripheral portion are disposed in a substantially U shape when viewed from a cross section along the axial direction.   At least one of a portion of the first holding member that engages with the transmission member, a portion of the transmission member that engages with the driving member, and a portion of the second holding member that engages with the driving member. The lens barrel according to claim 1, wherein the lens barrel is located in the vicinity of the guide shaft. The drive member is provided on the inner peripheral side of the reference member,
The lens mirror according to any one of claims 1 to 5, wherein the pair of bearing portions are provided so as to penetrate the drive member from the reference member and protrude toward the inner peripheral side. Tube. The first holding member is fixed to one end of the guide shaft,
The lens barrel according to claim 1, wherein the guide shaft is disposed on the other end side in the axial direction from the transmission member. The lens barrel according to claim 7 , wherein a distance between the transmission member in the axial direction and the bearing portion on the one end side is smaller than a distance between the pair of bearing portions . An imaging apparatus comprising: the lens barrel according to any one of claims 1 to 8; and an imaging unit that captures an image connected by the lens barrel.