JP5183122B2 - Barrier mechanism and lens barrel - Google Patents

Description

  The present invention relates to a barrier mechanism incorporated in a lens barrel of, for example, a digital camera, a silver salt camera, or a video camera.

  In a high-magnification zoom lens barrel with a built-in barrier mechanism, since the first lens group is a convex lens, the inner part of the zoom lens appears to be enlarged from the second lens group, and the dust that has entered inside is enlarged. For this reason, even trash that cannot be seen with the naked eye has poor aesthetics, and more strict measures to prevent dust from entering are required.

  As a conventional lens barrier mechanism, for example, a mechanism including a barrier blade that opens and closes the front surface of a lens by a rotation operation and a barrier driving member that drives the barrier blade is known (Patent Document 1).

  This barrier mechanism regulates the barrier driving member in the optical axis direction by a partition plate that partitions the barrier blade and the barrier driving member in the optical axis direction. As the lens barrel moves in the optical axis direction, the barrier driving member is rotated by the action of a rotating member such as a cam barrel or a fixed cam, whereby the barrier blades rotate (open and close) on the partition plate. .

  By the way, in recent years, due to a reduction in the number of parts, a structure has been adopted in which the barrier driving member is directly incorporated into the lens barrel by the bayonet structure and regulated in the optical axis direction, and the barrier blades rotate on the barrier driving member.

  19 to 21 show a conventional first group lens barrel having a bayonet structure.

  FIG. 19 is a view of the first group barrel before the barrier driving member is assembled, as viewed from the image plane side. FIG. 20 is a view of the first group barrel incorporating the barrier drive member as seen from the image plane side, and FIG. 21 is a view of the first group barrel incorporating the barrier drive member as seen from the subject side.

  As shown in FIGS. 19 to 21, the first group lens barrel 101 includes a bayonet claw portion 101 d that engages with a flange portion 113 d of a barrier drive member 113 and a bayonet claw portion 101 i that engages with a barrier cover (not shown). , 101j are provided in the circumferential direction. A hole 101l is formed on the image plane side of each bayonet claw portion 101d, 101i, 101j.

  Further, on the image plane side of the first group barrel 101, a shaft hole 101h serving as a rotation fulcrum of a barrier blade (not shown) and an interlocking lever 113f of the barrier driving member 113 are interlocked with the cam barrel and the first group mirror. A through hole 101 f for rotating in the cylinder 101 is formed.

Further, a technique is disclosed in which water that has entered the lens barrel by the flow of air when the lens barrel is retracted can be drained from a hole in the barrier of the lens barrel, and the hole is closed with a water-repellent sheet (Patent Document 2). ).
JP 2004-258120 A JP 2005-258276 A

  In the above conventional technique, the barrier blade is positioned on the subject side with respect to the first group lens barrel 101, and the cam cylinder and the fixed cam for rotating the barrier driving member 113 are positioned on the image forming side with respect to the first group lens barrel 101. . Therefore, the barrier driving member 113 needs to transmit the driving force across the first group lens barrel 101, and as described above, the first group lens barrel 101 needs the through hole 101f of the interlocking lever 113f.

  In this case, if the barrier driving member 113 is attached to the first group barrel 101 with a bayonet structure, it is necessary to form the through hole 101f in a wide angle range including the attachment phase of the bayonet claw portions 101d, 101i, 101j. The through hole 101f cannot be completely covered with a water repellent sheet or the like as in Patent Document 2 described above, and even if a part of the through hole 101f is blocked, the barrier driving member 113 may be obstructed to rotate. is there.

  Further, in the lens barrel of the molded product, if the undercut is eliminated due to the mold structure, a hole for allowing a part of the mold to protrude in a convex shape from the surface of the mold split is formed. This is because the inner side of the mold on the opposite side is formed. Accordingly, dust such as sand and dust can easily enter the lens barrel from the hole or through hole 101f.

  If dust such as sand or dust enters the lens barrel from the opening of the barrier mechanism, it may cause malfunction, and if dust enters the lens barrel, sand or dust may enter the lens barrel. I can see it. In particular, when the first lens group is a convex lens, there is a problem that the appearance is deteriorated because dust such as sand and dust appears enlarged.

Therefore, an object of the present invention is to provide a mechanism capable of preventing dust from entering the lens barrel from the through hole of the interlocking lever of the barrier mechanism .

To achieve the above object, the barrier mechanism of the present invention, the barrier driving for opening and closing a lens barrel which holds the lens, and barrier blades to protect the lens held in the lens barrel, the barrier blade by rotating and a member, the barrier driving member has an interlocking lever rotational force is transmitted, the barrel, the barrier mechanism having a through hole through which the interlocking lever, the barrier driving member, said barrier blade from the open state during rotation caused by the operation of to the closed state, in the optical axis direction have a cormorant flange portion covering the through hole from the object side, the barrel, the barrier driving engaged with the flange portion A bayonet claw that restricts relative movement of the member in the optical axis direction with respect to the lens barrel, and the bayonet claw is formed with a molding hole perpendicular to the optical axis in the lens barrel; The lens barrel , And having a cover member for covering the forming hole.

  According to the present invention, the barrier driving member has the flange portion that covers the through hole through which the interlocking lever is passed from the optical axis direction during the rotation accompanying the operation from the open state to the closed state of the barrier blade. It is possible to prevent dust from entering the lens barrel from the hole.

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

(First embodiment)
1 is a cross-sectional view for explaining a lens barrel (collapsed state) including a barrier mechanism according to a first embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a lens shown in FIG. FIG. 4 is a partial enlarged view of FIG.

  5 is a perspective view of the first group barrel, FIG. 6 is a perspective view of the second group barrel, and FIG. 7 is a perspective view showing the relationship between the second group barrel, the third group barrel, and the aperture shutter unit.

  As shown in FIGS. 1 to 4, the lens barrel is composed of a first group barrel 1, a second group barrel 2, a third group barrel 3, a fourth group barrel 4, a CCD holder 5, an aperture shutter unit 6, and a moving cam. 71, a drive cylinder 73, a rectilinear cylinder 74, and a cover cylinder 75 that covers and protects the entire lens barrel.

  The first group barrel 1 has a first group lens 10 therein and moves integrally with the first group lens 10 in the optical axis direction. The first group lens 10 is held by a first group lens holding frame 11 and is fixed to the first group lens barrel 1 via a first group adjustment ring 12. The first group lens 10 is a convex lens having optically positive power.

  On the inner peripheral side of the first group barrel 1, a metal cam pin 1a is integrally press-fitted. Further, the first group barrel 1 is provided with three stepped receiving surfaces 1g (see FIG. 5). The height of the receiving surface 1g that receives the optical axis direction of the first group adjusting ring 12 can be changed according to the angle phase at which the first group adjusting ring 12 is assembled, thereby adjusting the position of the first group lens 10 in the optical axis direction. .

  The first group lens holding frame 11 is provided with a spherical R surface 11 a that contacts the conical surface 12 a of the first group adjustment ring 12. By changing the angle of the first group lens holding frame 11, the first group lens 10 can be tilted and adjusted so that the optical performance of the entire photographing lens is adjusted to be the best.

  After the tilting of the first group lens 10 is adjusted and the first group lens 10 is adhered, a barrier mechanism (to be described later) is incorporated in the first group lens barrel 1, and finally the cover is covered with a decorative plate 18.

  The second group barrel 2 holds the second group lens 20, and a cam pin 2a (see FIG. 6) provided integrally with the second group barrel 2 is along the cam groove 71e of the movable cam barrel 71 in the optical axis direction. The second group lens barrel 2 moves straight by moving to.

  Two grooves 2 c concentrically with the second group lens 20 are formed on the entire circumference in the circumferential direction at a portion facing the subject side of the second group barrel 2. The wall surface on the inner peripheral side of the groove 2c is a cylindrical surface 2d substantially parallel to the optical axis, and the wall surface on the outer peripheral side of the groove 2c is an all-round tapered surface 2e that gradually increases in diameter toward the subject side.

  As shown by an arrow O in FIG. 4, the cylindrical surface 2d on the inner peripheral side of the groove 2c has a second group lens in the center of the dust 100g by hooking the dust 100g when dust 100g such as sand or dust enters. Blocks reaching 20.

  Further, since the diameter of the groove 2c is larger than the diameter on the R2 surface side of the first group lens 10, even when the first group lens 10 is enlarged by a convex lens when viewed from the subject side, the groove 2c extends from the subject side. It is almost impossible to see.

  Since the cylindrical surface 2d on the inner circumferential side of the groove 2c is formed along the entire circumference, as shown by an arrow Q in FIG. Move along 2c in the direction of arrow Q (downward).

  Further, when the lens barrel is moved to change the posture or when an external force such as gravity is applied, the dust 100g caught in the groove 2d travels along the entire peripheral tapered surface 2e on the outer peripheral side of the groove 2c and is off the optical axis. Is discharged in the direction of arrow P. Thereby, it can be set as the structure where dust does not enter into the range seen through the 1st group lens 10 easily.

  In the third group lens barrel 3, a third group lens 30 is held by a third group lens holding frame 31. The third group lens holding frame 31 is formed integrally with the two magnets 31a, and is pressed against the third group barrel 3 by a spring (not shown) in the optical axis direction with the three balls 35 interposed therebetween.

  The third group lens barrel 3 is provided with a coil 32 and a hall element 33 fixed with a magnet 31a portion of the third group lens holding frame 31 interposed therebetween. The coil 32 and the hall element 33 are arranged via a flexible substrate 34. It is connected to a control board (not shown).

  By energizing the coil 32 through the flexible substrate 34, the third group lens holding frame 31 within the third group lens barrel 3 receives electromagnetic force in a direction perpendicular to the optical axis, and the balls 35 described above become rolling elements, It can move on a plane orthogonal to the optical axis.

  Since the Hall element 33 changes the output by changing the position of the magnet 31a, the movement amount of the third group lens holding frame 31 can be detected based on the output change.

  The fourth group barrel 4 holds a fourth group lens 40 and is supported by two guide bars (not shown) so as to be movable in the optical axis direction. A screw screw 42a is formed on the motor shaft of the AF motor 42 that drives the fourth group lens barrel 4, and a nut 41 is screwed onto the screw screw 42a.

  The fourth group barrel 4 is biased in the optical axis direction with respect to the nut 41 by a tension spring (not shown). Therefore, when the AF motor 42 is driven, the nut 41 moves in the optical axis direction, so that the fourth group barrel 4 moves in the optical axis direction.

  The CCD holder 5 is a frame for holding the CCD sensor 50. An elastic member 52 such as rubber is disposed on the subject side of the CCD sensor 50, and an IR cut filter 51 is disposed between the elastic member 42 and the CCD sensor 50.

  The elastic member 52, the IR cut filter 51, and the CCD sensor 50 are unitized by being sandwiched between the IR plate 54 and the CCD plate 53 in the optical axis direction. This unit is pressed and fixed to the CCD holder 5 with a screw (not shown).

  The aperture shutter unit 6 is connected to a control board (not shown) via a flexible board 63. The aperture shutter unit 6 has two shutter blades 61 on the object side and six aperture blades 62 on the image plane side.

  The two shutter blades 61 can be electrically opened and closed by electromagnetic driving. The six aperture blades 62 are simultaneously opened and closed by driving a motor (not shown), thereby changing the aperture diameter to control the aperture value.

  The movable cam cylinder 71 has a cam groove 71d formed on the outer peripheral side, a cam groove 71e, a cam groove 71f, and a cam groove 71g formed on the inner peripheral side, and the cam pin 71a, the drive pin 71b, and the claw 71c are integrated. Is formed.

  The fixed cylinder 72 has a cam groove 72a on the inner peripheral side, and the cam pin 71a of the movable cam cylinder 71 can move along the cam groove 72a.

  The drive cylinder 73 is rotatably fitted to the outer peripheral portion of the fixed cylinder 72, and a gear portion (not shown) is integrally formed on the outer peripheral side. The gear unit is connected to a PZ motor (not shown) via a speed reduction mechanism (not shown).

  The rectilinear cylinder 74 has a key portion 74a on the outer peripheral portion of the end on the image plane side, and the key portion 74a is fitted into a groove 72b formed on the inner peripheral side of the fixed cylinder 72, whereby rotation is restricted. In this state, it can move in the optical axis direction along the groove 72b.

  Since the key portion 74a of the rectilinear cylinder 74 is restricted from moving in the optical axis direction by the claw 71c of the moving cam cylinder 71, the rectilinear cylinder 74 rotates together with the moving cam cylinder 71 that moves in the optical axis direction while rotating. Without moving in the direction of the optical axis.

  Next, an operation example of the lens barrel configured as described above will be described.

  The drive cylinder 73 is rotated by the rotational drive of the PZ motor. The drive cylinder 73 is formed with a longitudinal groove 73 a on the inner peripheral side along the optical axis direction. The drive pin 71 b of the moving cam cylinder 71 is fitted into the longitudinal groove 73 a so that the drive pin 71 b is relative to the drive cylinder 73. Therefore, it is possible to go straight along the optical axis direction.

  Further, since the drive pin 71b is fitted in the vertical groove 73a, when the drive cylinder 73 rotates, the movable cam cylinder 71 rotates at the same time, and the movable cam cylinder 71 moves in the optical axis direction while rotating along the cam groove 72a. To do.

  When the cam pin 71a of the movable cam barrel 71 moves linearly in the optical axis direction while rotating along the cam groove 72a of the fixed barrel 72, the straight advance key 1b of the first group barrel 1 enters a straight advance groove (not shown) of the straight advance cylinder 74. Therefore, the first lens barrel 1 does not rotate but moves straight in the optical axis direction.

  Further, since the metal cam pin 1a on the inner peripheral side of the first group barrel 1 moves along the cam groove 71d on the outer peripheral side of the movable cam barrel 71, the first group barrel 1 moves back and forth in the optical axis direction. .

  Similarly, the second group barrel 2 is integrally formed with a cam pin 2a and a rectilinear rib 2b, and the third group barrel 3 is integrally formed with a cam pin 3a, a rectilinear key 3b, and a rectilinear rib 3c. A cam pin 6a and a straight advance key 6b are integrally formed (see FIG. 7).

  The cam pin 2a moves along the cam groove 71e, the cam pin 3a moves along the cam groove 71f, and the cam pin 6a moves along the cam groove 71g.

  Referring to FIG. 7, the rectilinear rib 3c of the third group barrel 3 is a pair of ribs, and the rectilinear key 6b of the aperture shutter unit 6 is inserted between the two ribs. It arrange | positions so that the rectilinear rib 2b of the 2nd group barrel 2 may pinch | interpose the outer side of the circumferential direction.

  The second group barrel 2, the third group barrel 3, and the aperture shutter unit 6 move straight in the optical axis direction without rotating.

  In the third group lens barrel 3, since the rectilinear key 3b is fitted into the rectilinear groove 72b of the fixed cylinder 72 from the rear of the rectilinear cylinder 74, the third group lens barrel 3 moves in the optical axis direction without rotating. The second group lens barrel 2 and the aperture shutter unit 6 can move straight in the optical axis direction without rotating.

  As described above, the positions of the first group lens 10, the second group lens 20, the third group lens 30, and the aperture shutter unit 6 can be moved in the optical axis direction by rotational driving of the PZ motor.

  Then, by appropriately designing the curve of each cam groove, the optical system can be moved from the retracted position to the photographing state position and from the wide end to the tele end in the zoom region of the optical system.

  Next, with reference to FIGS. 8-15, the barrier mechanism which is the 1st Embodiment of this invention is demonstrated.

  FIG. 8 is an exploded perspective view for explaining the barrier mechanism according to the present embodiment. 9 is a front view of the barrier mechanism shown in FIG. 8 with the barrier blades closed, FIG. 10 is a front view of the barrier mechanism shown in FIG. 8 with the barrier blades open, and FIG. 11 is a view of the barrier mechanism shown in FIG. It is a front view in the state in the middle of rotation with the barrier blade | wing approaching opening.

  12 is a view of the two pairs of barrier blades as viewed from the image plane side, FIG. 13 is a view for explaining the relationship between the barrier drive ring and the movable cam barrel, and FIGS. 14 and 15 are the first group barrel and the barrier. It is the elements on larger scale of a drive ring.

  As shown in FIG. 8, the barrier mechanism of the present embodiment includes a barrier drive ring (barrier drive member) 13, a barrier cover 14, a barrier inner blade 15, a barrier outer blade 16, and a spring 17.

  As shown in FIGS. 8 and 9, the barrier drive ring 13 is provided with flange portions 13 d that protrude radially outward at three locations in the circumferential direction. The flange portion 13d is engaged with and hooked to the three bayonet claw portions 1d of the first group barrel 1 by the bayonet structure, so that the position in the optical axis direction is regulated from the subject side.

  With reference to FIG. 3, the position of the imaging plane side in the optical axis direction is regulated by sliding the rail portion 13 e of the barrier drive ring 13 and the rail portion 1 e of the first group barrel 1 in contact with each other. . Further, in the direction perpendicular to the optical axis, the diameter fitting hole 1k of the first group barrel 1 and the diameter fitting portion 13h of the barrier drive ring 13 are fitted in the radial direction so that the barrier drive ring 13 can rotate. Held in a state.

  As shown in FIG. 9, the barrier drive ring 13 is formed with a tapered hole 13a that widens from the image plane side toward the subject side. The position of the hole 13a is located on the radially outer side of the outer peripheral portion 15d of the barrier inner blade 15 in the barrier closed state and on the outer side in the radial direction with respect to the barrier outer blade 16 as well.

  The position of the hole 13a is determined by the fitting portion between the diameter fitting portion 13h of the barrier drive ring 13 and the diameter fitting hole 1k of the first group barrel 1, and the sliding portion between the rail portion 13e and the rail portion 1e. Is also arranged radially inward.

  The outer peripheral portion of the hole 13a on the image forming surface side has a shape protruding in a tapered shape that gradually becomes thinner toward the image forming surface side with reference to FIGS.

  That is, the hole 13a on the image plane side is narrowed and the outer periphery thereof is tapered. This makes it possible to make it difficult for dust once entering the hole 13a to come out of the hole 13a again when the lens barrel is turned downward, and to make it easier to get dust from the opening 13b of the first lens group 10. it can.

  The barrier cover 14 is a lid member having an opening hole of the first group lens 10, and two claws 14 a and two claws 14 b are formed on the outer peripheral portion.

  The barrier cover 14 is fixed to the first group barrel 1 by rotating the barrier cover 14 and hooking the claws 14 a and 14 b on the bayonet claws 1 i and 1 j of the first group barrel 1. 9 to 11, the illustration of the barrier cover 14 is omitted for convenience of explanation.

  The two barrier inner blades 15 and the two barrier outer blades 16 are arranged so as to be openable and closable so that their rotational directions are symmetrical, and close the opening hole of the barrier cover 14 in the closed state to protect the first group lens 10. To do.

  A shaft 15 a is projected from the front and back of the base portion of the barrier inner blade 15. One shaft 15 a is fitted into the hole 1 h of the first group barrel 1, and the other shaft 15 a is a hole 16 c of the barrier outer blade 16. Is fitted. As a result, the barrier inner blade 15 and the barrier outer blade 16 can rotate coaxially about the shaft 15a.

  When opening, the outer peripheral portion 15 d of the barrier inner blade 15 is hooked on the claw 16 a of the barrier outer blade 16, and when closing, the tip portion 15 b of the barrier inner blade 15 is hooked on the claw 16 b of the barrier outer blade 16. Thereby, the barrier outer blade 16 is rotationally driven in conjunction with the movement of the barrier inner blade 15.

  The spring 17 is a tension spring and is stretched between the hook portions 15e of the two inner barrier blades 15 and the shaft 13g of the barrier drive ring 13 to attract them. The interlocking lever 13f of the barrier drive ring 13 passes through the hole 1f of the first group barrel 1 and is disposed at a position where the tip reaches the movable cam barrel 71 when retracted.

  As shown in FIG. 13, the movable cam cylinder 71 has a notch 71h at a position corresponding to the interlocking lever 13f, and the notch 71h can be rotated by pushing the interlocking lever 13f in the rotation direction.

  As shown in FIG. 5, the bayonet claw portions 1d, 1i, 1j of the first group barrel 1 are all slide-formed in the lateral direction perpendicular to the optical axis, so that the image plane side of the bayonet claw portions 1d, 1i, 1j All have a horizontal hole 1c for slide molding. The horizontal hole 1c is closed by a decorative board (cover member) 18 so that dust does not enter.

  As a result, in the first group lens barrel 1, in addition to the hole portion 1 f, a through hole is formed only in a portion where the hole 1 h into which the shaft 15 a of the barrier inner blade 15 is fitted and the first group lens 10 enter. The hole 1 h is closed by the barrier inner blade 15, and the portion where the first group lens 10 enters is also closed by the first group lens 30, the first group lens holding frame 11, and the first group adjustment ring 12.

  Regarding the remaining hole 1f, as shown in FIGS. 14 and 15, the interlocking lever 13f of the barrier drive ring 13 and one of the three flange portions 13d are arranged in the same phase. During the operation from the open state to the closed state of the barrier blade, the angular range of the flange portion 13d is sufficiently large so that the hole 1f is always covered with the flange portion 13d.

  Thereby, while the flange part 13d of the interlocking lever 13f rotates from the open state to the closed state of the barrier blade by the rotation of the barrier drive ring 13, the hole 1f can always be covered with the flange part 13d. As a result, as shown in FIG. 4, the dust 100d can be prevented from entering from the hole 1f.

  When the barrier inner blade 15 and the barrier outer blade 16 are closed, the barrier drive ring 13 is interlocked with the rotation of the movable cam cylinder 71 by the action of the notch 71h of the movable cam cylinder 71 and the interlocking lever 13f shown in FIG. Rotate. Thereby, the barrier inner blade 15 and the barrier outer blade 16 rotate in the closing direction.

  When the barrier drive ring 13 is in the barrier closed state, the interlocking lever 13f is pushed by the movable cam cylinder and rotated in the direction of arrow A in FIG. 9, thereby receiving the force in the direction of arrow A centering on the optical axis. Rotate to position phase.

  At this time, the spring 17 is charged, and one barrier inner blade 15 of the two barrier inner blades 15 is rotated in the direction of arrow B about the shaft 15a by being pulled by the spring 17, and the other barrier inner blade 15 and Stop at the position where you hit.

  Further, the barrier outer blade 16 also rotates in the direction of arrow C by the action of the barrier inner blade 15 described above, and the barrier inner blade 15 and the barrier outer blade 16 are closed.

  When the inner barrier blade 15 and the outer barrier blade 16 are opened, when the force applied to the interlocking lever 13f is released by the rotation of the movable cam cylinder 71, as shown in FIG. The drive ring 13 rotates in the direction of arrow G.

  As a result, the barrier drive ring 13 starts rotating with the rotational force in the direction of arrow H when the wall 13c of the barrier drive ring 13 presses the protrusion 15c of the barrier inner blade 15 at a certain phase.

  At this time, since the outer peripheral portion 15d of the barrier inner blade 15 hits the claw 16a of the barrier outer blade 16, the barrier outer blade 16 also starts to rotate in the direction of arrow I. In FIG. 11, only one side of the barrier outer blade 16 is removed.

  Further, when the notch portion 71h of the moving cam cylinder 71 and the interlocking lever 13f are separated from each other, nothing restricts the rotation of the barrier drive ring 13, so that the barrier drive ring 13 further rotates in the direction of arrow D where the spring 17 is loosened.

  The bayonet claw 1j also functions as a stopper for the barrier inner blade 15. The barrier inner blade 15 rotates in the direction of arrow E until the outer peripheral portion 15d of the barrier inner blade 15 hits the bayonet claw portion 1j, and the barrier outer blade 16 is also pushed by the outer peripheral portion 15d of the barrier inner blade 15 to integrally move the arrow F And the barrier is opened as shown in FIG.

  When dust is caught between the barrier inner blade 15 and the barrier drive ring 13 during the opening operation of the barrier inner blade 15, the dust 100 e shown in FIG. It is possible to sweep from the hole 13a of the barrier drive ring 13 to the position of the dust 100c.

  2 is attached to the side surface of the blade through the gap between the barrier inner blade 15 and the barrier outer blade 16 as indicated by an arrow J. It is possible to sweep from 13a to the position of garbage 100c.

  Similarly, the dust 100b in FIG. 2 attached to the side surface of the blade through the gap between the barrier outer blade 16 and the barrier cover 14 is swept from the hole 13a of the barrier drive ring 13 to the position of the dust 100c as indicated by an arrow K. be able to.

  Further, since the tapered hole 13a rotates the outer peripheral portion 15d of the barrier inner blade 15, dust attached to a wider blade range can be dropped into the hole 13a.

  Further, since the position of the tapered hole 13a is substantially covered by the barrier inner blade 15 in the barrier open state, dust can be prevented from coming out of the hole 13a in the open state. As indicated by N, dust 100f comes out of the lens opening 13b.

  Moreover, since it becomes difficult for dust to reach the diameter fitting portion 13h, the rail portion 13e, and the flange portion 13d of the barrier drive ring 13, the movement of the barrier drive ring 13 is less likely to be hindered.

(Second Embodiment)
Next, a barrier mechanism that is a second embodiment of the present invention will be described with reference to FIGS.

  16 is a front view when the barrier blades of the first group barrel incorporating the barrier drive ring are opened, FIG. 17 is a front view when the barrier blades of the first group barrel shown in FIG. 16 are closed, and FIG. It is a front view which shows the single body of a barrier drive ring. FIG. 22 is a front view of the first group barrel before incorporating the barrier drive ring as seen from the image plane side. Note that the description and illustration of the parts overlapping with those in the first embodiment are omitted.

  In the barrier mechanism of this embodiment, as shown in FIGS. 16, 17, and 22, bayonet claw portions 201d, 201i, and 201j are formed in the first group barrel 201. A through-hole 201l for molding each bayonet claw 201d, 201i, 201j is formed in the optical axis direction at each bayonet claw 201d, 201i, 201j.

  Further, the first group barrel 201 is formed with a through hole 201f through which the interlocking lever 213f is passed. In the figure, since the through hole 201f is disposed adjacent to the bayonet claw portion 201d, the through hole 201f is enlarged in the circumferential direction only in the same manner as the other through holes 201l.

  As shown in FIG. 18, the barrier drive ring 213 is provided with three flange portions 213d and two flange portions 213i in the circumferential direction. Sheet-like flexible members 219 are integrally attached to the three flange portions 213d and the one flange portion 213i.

  Examples of the material of the flexible member 219 include a sheet of PET material, a sheet of polyester film, or a rubber member such as NBR, but is not particularly limited as long as the material is thin, flexible, and deformable.

  The flexible member 219 is provided with three flange portions 213d and one flange portion 213i of the barrier drive ring 213 by bonding means such as an adhesive or double-sided tape, and the positions of the through holes 201f and 201l of the first group barrel 201. It is pasted at the position corresponding to. The flexible member 219 attached to the three flange portions 213d is attached so as to expand the flange portion 213d in the circumferential direction.

  When the flexible member 219 is attached, the flexible member 219 hits the bayonet claw portions 201d, 201i, 201j on the first lens barrel 201 side in the built-in phase, but the flexible member 219 is deformed. Can be easily incorporated. Note that the flexible member 219 may be attached to the barrier drive ring 213 after the barrier drive ring 213 is incorporated into the first group lens barrel 201.

  As described above, in this embodiment, since the through holes 201f and 201l can be covered by the flexible member 219 that is integrally attached to the barrier drive ring 213, dust is put into the first group lens barrel 201. Can be difficult. Other configurations and operational effects are the same as those of the first embodiment.

  In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in each of the embodiments described above, the barrier mechanism used for the digital camera is exemplified, but the present invention is not limited to this, and the present invention is used for a silver salt camera, a video camera, a portable device with a camera function, and other optical devices and optical devices. The present invention may be applied to a barrier mechanism to be used.

It is sectional drawing for demonstrating a lens-barrel (collapsed state) provided with the barrier mechanism which is the 1st Embodiment of this invention. It is the elements on larger scale of FIG. It is sectional drawing in the imaging | photography state of the wide end of the lens-barrel shown in FIG. FIG. 4 is a partially enlarged view of FIG. 3. It is a perspective view of a first group barrel. It is a perspective view of a 2nd group barrel. It is a perspective view which shows the relationship between a 2nd group lens barrel, a 3rd group lens barrel, and an aperture shutter unit. It is a disassembled perspective view for demonstrating the barrier mechanism which is the 1st Embodiment of this invention. It is a front view in the closed state of the barrier blade | wing of the barrier mechanism shown in FIG. It is a front view in the open state of the barrier blade | wing of the barrier mechanism shown in FIG. It is a front view in the state in the middle of rotation in which the barrier blade | wing of the barrier mechanism shown in FIG. It is the figure which looked at two pairs of barrier blades from the image plane side. It is a figure for demonstrating the relationship between a barrier drive ring and a moving cam cylinder. It is the elements on larger scale of a 1st group lens barrel and a barrier drive ring. It is the elements on larger scale of a 1st group lens barrel and a barrier drive ring. It is a figure for demonstrating the barrier mechanism which is the 2nd Embodiment of this invention, and is a front view at the time of the open state of the barrier blade | wing of the 1st group lens barrel incorporating the barrier drive ring. FIG. 17 is a front view when the barrier blades of the first group barrel shown in FIG. 16 are closed. It is a front view which shows the single body of a barrier drive ring. It is a figure which shows the conventional 1 group lens barrel which has a bayonet structure, and is the front view which looked at the conventional 1 group lens barrel before incorporating a barrier drive member from the image plane side. It is the front view which looked at the conventional 1 group barrel incorporating a barrier drive member from the image plane side. It is the front view which looked at the conventional 1 group lens barrel incorporating the barrier drive member from the to-be-photographed object side. It is the front view which looked at the 1st group barrel of this embodiment before incorporating a barrier drive ring from the image plane side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st group lens barrel 1c Side hole 1d Bayonet nail | claw part 1e Rail part 1f Through-hole 1k Diameter fitting part 2 2nd group lens barrel 2c Groove 10 1st group lens 13 Barrier drive ring 13a Hole 13d Flange part 13e Rail part 13f Linking lever 13h Diameter Fitting portion 14 Barrier cover 15 Barrier inner blade 16 Barrier outer blade 17 Spring 18 Decorative plate 201 Group 1 lens barrel 201d Bayonet claw portion 201f Through hole 213 Barrier drive ring 213d Flange portion 213f Interlocking lever 213i Flange portion 219 Flexible member

Claims (2)

Comprising a lens barrel which holds the lens, and barrier blades to protect the lens held in the lens barrel, and a barrier driving member for opening and closing the barrier blade by rotating,
In the barrier mechanism, the barrier driving member has an interlocking lever to which a rotational force is transmitted, and the lens barrel has a through hole through which the interlocking lever passes.
The barrier drive member, from the open state of the barrier blades during rotation caused by the operation of to the closed state, have a power sale flange portion covering the through hole from the object side in the optical axis direction,
The lens barrel includes a bayonet claw portion that engages with the flange portion and restricts relative movement of the barrier driving member in the optical axis direction with respect to the lens barrel;
In the bayonet claw portion, a forming hole perpendicular to the optical axis is formed in the lens barrel , and the lens barrel has a cover member that covers the forming hole . A lens barrel having the barrier mechanism according to claim 1.

Images