JP2011075608A - Lens barrel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the occurrence of a ghost and a flare. <P>SOLUTION: A lens barrel device 2 includes: a first lens group frame 40; a second lens group frame 50 arranged inside the first lens group frame 40; a key ring 30 arranged outside the first lens group frame 40 for regulating the rotation of the first lens group frame 40 and the second lens group frame 50; a cam cylinder 20 arranged outside the key ring 30 for moving the first lens group frame 40 and the second lens group frame 50 by rotating in a circumferential direction with respect to the key ring 30 so that the second lens group frame 50 is inserted into the first lens group frame 40, or the first lens group frame 40 extends toward the object side from the second lens group frame 50; and a light shielding cylinder 70 which is inserted into the first lens group frame 40, disposed slidably in the optical axis direction with respect to the first lens group frame 40, externally mounted to the second lens group frame 50, and disposed slidably in the optical axis direction with respect to the second lens group frame 50. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens barrel device.

  As a lens barrel device for a zoom lens, one having a fixed barrel, a cam barrel, a key ring, a first lens group frame, and a second lens group frame is known (see, for example, Patent Document 1 and Patent Document 2). .

  In the lens barrel device 102 shown in FIG. 4, the cam barrel 120 is disposed inside the fixed barrel 110, the first lens group frame 140 is disposed inside the cam barrel 120, and the key ring 130 is the first lens group frame. The second lens group frame 150 is disposed inside the key ring 130. The cam cylinder 120 and the key ring 130 are integrated with each other so as to be movable back and forth with respect to the fixed cylinder 110. The key ring 130 is restricted from rotating in the radial direction with respect to the fixed cylinder 110, and the cam cylinder 120 is provided to be rotatable in the radial direction with respect to the fixed cylinder 110 and the key ring 130. A cam groove for the first lens group frame 140 and a cam groove for the second lens group frame 150 are formed on the inner peripheral surface of the cam cylinder 120. The key ring 130 is formed with a rectilinear groove for the first lens group frame 140 and a rectilinear groove for the second lens group frame 150, and the first lens group frame 140 and the second lens group frame 150 rotate in the radial direction. Is regulated by the key ring 130. In such a lens barrel device 102, when the cam barrel 120 rotates in the radial direction, the first lens group frame 140 and the second lens group frame 150 move back and forth according to the shape of each cam groove.

JP 2000-229270 A JP 2006-047747 A

  In recent years, in order to reduce the thickness of the camera, it is desired to shorten the front and rear lengths of the fixed cylinder 110, the cam cylinder 120, the key ring 130, the first lens group frame 140, and the second lens group frame 150. On the other hand, when the front and rear lengths of the fixed cylinder 110, the cam cylinder 120, the key ring 130, the first lens group frame 140, and the second lens group frame 150 are shortened, the front and rear of the first lens group frame 140 and the second lens group frame 150 are reduced. The moving distance is shortened and the zoom magnification is reduced.

  Therefore, the front and rear of the first lens group frame 140 and the second lens group frame 150 are shortened while shortening the front and rear lengths of the fixed cylinder 110, the cam cylinder 120, the key ring 130, the first lens group frame 140, and the second lens group frame 150. As shown in FIG. 5, the key ring 130 is disposed outside the first lens group frame 140 so that the movement distance of the first lens group 140 is not shortened.

  However, when the key ring 130 is disposed outside the first lens group frame 140, the light is outside the second lens group frame 150 when the first lens group frame 140 is extended forward from the second lens group frame 150. (See the arrow in FIG. 5), ghost and flare are generated.

  Therefore, a problem to be solved by the present invention is to suppress generation of ghost and flare.

  In order to solve the above problems, a lens barrel device according to the present invention includes a first lens group frame, a second lens group frame disposed inside the first lens group frame, and the first lens group frame. A key ring that is disposed outside, holds the first lens group frame and the second lens group frame so as to be movable in the optical axis direction and restricts rotation in the circumferential direction; and disposed outside the key ring, By rotating in the circumferential direction with respect to the key ring, the second lens group frame enters the first lens group frame and the first lens group frame is moved from the second lens group frame to the subject side. A cam cylinder that moves the first lens group frame and the second lens group frame to the projected state, and is inserted into the first lens group frame, and slides in the optical axis direction with respect to the first lens group frame. It is provided so as to be movable, and is externally attached to the second lens group frame. A shielding tube which is slidably in the axial direction, and a further comprising a.

  Preferably, the lens barrel device includes a first slider projecting on one of an inner peripheral surface of the first lens group frame and an outer peripheral surface of the light shielding cylinder, and an inner portion of the first lens group frame. A first guide groove that is recessed in the other of the peripheral surface and the outer peripheral surface of the light-shielding cylinder and that holds the first slider movably in the optical axis direction; an outer peripheral surface of the second lens group frame; A second slider projecting on one of the inner peripheral surfaces of the light shielding cylinder, and a concave on the other of the outer peripheral surface of the second lens group frame and the inner peripheral surface of the light shielding cylinder, And a second guide groove for holding the second slider movably in the optical axis direction.

  Preferably, the lens barrel device is provided between an outer peripheral surface of the light-shielding tube and an inner peripheral surface of the first lens group frame, and the light-shielding tube comes out from the first lens group frame toward the imaging surface side. It was further provided with the 1st drop prevention part which prevents this.

  Preferably, the lens barrel device is provided between an inner peripheral surface of the light-shielding tube and an outer peripheral surface of the second lens group frame, and the second lens group frame comes out of the light-shielding tube toward the image plane. It was further provided with a second slip-off prevention part for preventing the above.

  Preferably, the lens barrel device further includes a third omission prevention portion that is provided on an inner circumferential surface of the light shielding cylinder and prevents the second lens group frame from coming out of the light shielding cylinder toward the subject. did.

  According to the present invention, since the light-shielding tube is inserted into the first lens group frame and is externally mounted on the second lens group frame, the first lens group frame is retracted from the second lens group frame. A gap between the one lens group frame and the second lens group frame is closed by the light shielding cylinder. For this reason, it is possible to prevent the light from sneaking out of the second lens group frame and generating ghost and flare.

It is sectional drawing which showed the lens barrel apparatus of the retractable state which concerns on embodiment of this invention, and a zoom lens apparatus provided with the same. It is sectional drawing which showed the lens barrel apparatus of the wide angle state which concerns on the same embodiment, and a zoom lens apparatus provided with the same. It is sectional drawing which showed the telescopic lens-barrel apparatus concerning this embodiment, and a zoom lens apparatus provided with the same. It is sectional drawing which showed the conventional zoom lens. It is sectional drawing which showed the conventional zoom lens.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

  FIG. 1 is a cross-sectional view of the zoom lens device 1 in a retracted state. FIG. 2 is a cross-sectional view of the zoom lens device 1 in the wide angle state. FIG. 3 is a cross-sectional view of the zoom lens device in the telephoto state. As shown in FIGS. 1 to 3, the zoom lens apparatus 1 holds three lens groups 49, 59, and 69, and these lens groups 49, 59, and 69 and moves these lens groups 49, 59, and 69 back and forth. And a lens barrel device 2 to be moved. The lens barrel device 2 includes a fixed cylinder 10, a cam cylinder 20, a key ring 30, a first lens group frame 40, a second lens group frame 50, a third lens group frame 60, a light shielding cylinder 70, and the like.

The fixed cylinder 10 is provided integrally with an apparatus main body such as a camera. As shown in FIG. 1, the fixed cylinder 10 includes the cam cylinder 20, the key ring 30, the first lens group frame 40, the second lens group frame 50, the third lens group frame 60, the light shielding cylinder 70 and the like in the retracted state. Store in.
An image sensor 80 is provided at the rear end of the fixed cylinder 10. A third lens group frame 60 is provided in front of the image sensor 80. The third lens group frame 60 moves back and forth along the optical axis in conjunction with the cam cylinder 20 and the like by a drive mechanism (not shown). Note that “front” means the subject side, and “back” means the imaging plane (imaging element 80) side.
The third lens group frame 60 holds the third lens group 69. In the drawing, the number of single lenses in the third lens group 69 is one, but it may be plural.

  A cam cylinder 20 is disposed inside the fixed cylinder 10. On the outer peripheral surface of the cam cylinder 20, a projection 21 is provided so as to project. On the other hand, a cam cylinder guide groove 11 is formed on the inner peripheral surface of the fixed cylinder 10. The protrusion 21 is engaged with the cam cylinder guide groove 11. The cam cylinder guide groove 11 extends in the circumferential direction at the front portion thereof, and is provided in a spiral shape at the rear portion thereof. When the protrusion 21 is located at the rear part of the cam cylinder guide groove 11, the cam cylinder 20 rotates, so that the cam cylinder 20 is optically axised with respect to the fixed cylinder 10 by the rear part of the cam cylinder guide groove 11. Move back and forth along. This is a movement from the retracted state to the wide-angle state or vice versa. On the other hand, when the protrusion 21 is positioned at the front portion of the cam cylinder guide groove 11, the cam cylinder 20 rotates while being restricted in the back-and-forth movement with respect to the fixed cylinder 10. This is a movement from the wide-angle state to the telephoto state or vice versa.

  A gear 22 is formed at the rear end of the outer peripheral surface of the cam cylinder 20. The gear 22 is connected to a motor via a gear train, and the cam cylinder 20 is rotated by the motor.

  A cylindrical key ring 30 is disposed inside the cam cylinder 20. A convex portion 31 is provided on the outer peripheral surface of the key ring 30. On the other hand, a rectilinear groove 12 parallel to the optical axis is formed on the inner peripheral surface of the fixed cylinder 10. When the convex portion 31 engages with the rectilinear groove 12, the key ring 30 is guided in the front-rear direction along the optical axis while restricting radial rotation with respect to the fixed cylinder 10.

  Further, a rotation groove (not shown) along the radial direction is formed on the inner peripheral surface of the cam cylinder 20, and a sliding projection (not shown) is provided on the outer peripheral surface of the key ring 30. The moving projection is engaged with the rotating groove. Thereby, the cam cylinder 20 is provided so as to be rotatable with respect to the key ring 30 while restricting the forward and backward movement with respect to the key ring 30.

  A cylindrical first lens group frame 40 is disposed inside the key ring 30. A follower pin 41 is provided at the rear end of the outer peripheral surface of the first lens group frame 40. The follower pin 41 and the slide pin 42 are provided integrally, the follower pin 41 and the slide pin 42 are provided so as to penetrate the first lens group frame 40, and the follower pin 41 is convex on the outer peripheral surface of the first lens group frame 40. The sliding pin 42 is convexly provided on the inner peripheral surface of the first lens group frame 40.

  On the other hand, the key ring 30 is formed with a straight-groove 32 for a group lens parallel to the optical axis. A follower pin 41 is inserted into the straight movement groove 32 for the first group lens. As a result, the key ring 30 holds the first lens group frame 40 so as to be movable back and forth along the optical axis, and restricts the radial rotation of the first lens group frame 40.

  A cam groove 23 for the first lens group is formed on the inner peripheral surface of the cam cylinder 20. The follower pin 41 is engaged with the cam groove 23 for the first lens group. Thereby, the first lens group frame 40 is guided in the front-rear direction by the rotation of the cam cylinder 20.

  A first lens group 49 is held inside the first lens group frame 40. In the drawing, the number of single lenses in the first lens group 49 is two, but it may be one or three or more.

  A cylindrical second lens group frame 50 is disposed inside the first lens group frame 40. A follower pin 51 is provided at the rear end of the outer peripheral surface of the second lens group frame 50. On the other hand, the key ring 30 is formed with a straight groove 33 for a second group lens parallel to the optical axis. A follower pin 51 is inserted in the straight groove 33 for the second lens group. Accordingly, the key ring 30 holds the second lens group frame 50 so as to be movable back and forth along the optical axis, and restricts the rotation of the second lens group frame 50 in the radial direction.

  A cam groove 24 for a second lens group is formed on the inner peripheral surface of the cam cylinder 20. The follower pin 51 is engaged with the cam groove 24 for the second group lens. Thereby, the second lens group frame 50 is guided in the front-rear direction by the rotation of the cam cylinder 20.

  A second lens group 59 is held inside the second lens group frame 50. The second lens group frame 50 is provided with a diaphragm device 58 for adjusting the F value. In the drawing, the number of single lenses in the second lens group 59 is three, but it may be one or two, or four or more.

  The light shielding cylinder 70 is inserted into the first lens group frame 40, and the light shielding cylinder 70 is provided to be slidable in the front-rear direction with respect to the first lens group frame 40. The light shielding cylinder 70 is externally mounted on the second lens group frame 50, and the second lens group frame 50 is provided so as to be slidable in the front-rear direction with respect to the light shielding cylinder 70.

  A first guide groove 71 is recessed in the outer peripheral surface of the light shielding cylinder 70. The first guide groove 71 extends in the front-rear direction, and more preferably is provided parallel to the optical axis. On the other hand, a sliding pin 42 provided integrally with the follower pin 41 is provided at the rear end portion of the inner peripheral surface of the first lens group frame 40. The sliding pin 42 is engaged with the first guide groove 71. Thereby, the light shielding cylinder 70 is guided in the front-rear direction with respect to the first lens group frame 40 while being restricted from rotating in the radial direction with respect to the first lens group frame 40.

A first stopper 72 is formed at the front end portion of the first guide groove 71 so that the sliding pin 42 abuts against the first stopper 72 so as not to come forward from the first guide groove 71. As a result, the first stopper 72 and the sliding pin 42 function as a removal preventing portion that prevents the light shielding cylinder 70 from coming back from the first lens group frame 40, and the light shielding cylinder 70 is removed from the first lens group frame 40. It is designed not to come out backwards. On the other hand, the rear end of the first guide groove 71 is opened, and the sliding pin 42 can be pulled out rearward from the first guide groove 71.
A guide groove parallel to the optical axis is recessed on the inner peripheral surface of the first lens group frame 40, a sliding pin is protruded on the outer peripheral surface of the light shielding tube 70, and the sliding pin engages with the guide groove. May be. In this case, a stopper is formed at the rear end of the guide groove, and the front end of the guide groove is open.

  A second guide groove 73 is recessed in the inner peripheral surface of the light shielding cylinder 70. The second guide groove 73 is provided in parallel to the first guide groove 71. On the other hand, a sliding claw 52 is formed at the front end of the second lens group frame 50, and the sliding claw 52 protrudes inside the second lens group frame 50. The sliding claw 52 is engaged with the second guide groove 73. Thereby, the light shielding cylinder 70 is guided in the front-rear direction with respect to the second lens group frame 50 while being restricted from rotating in the radial direction with respect to the second lens group frame 50.

A second stopper 74 is formed at the rear end portion of the second guide groove 73 so that the sliding claw 52 abuts against the second stopper 74 so as not to come out rearward from the second guide groove 73. . As a result, the sliding claw 52 and the second stopper 74 function as a removal prevention unit that prevents the second lens group frame 50 from coming back out of the light shielding cylinder 70, and the second lens group frame 50 is removed from the light shielding cylinder 70. It is designed not to come out backwards.
A guide groove parallel to the optical axis may be recessed on the outer peripheral surface of the second lens group frame 50, a claw may be provided on the inner peripheral surface of the light shielding tube 70, and the claw may engage with the guide groove. . In this case, a stopper is formed at the front end of the guide groove.

  A convex portion 75 is formed at the front end portion of the light shielding cylinder 70, and the convex portion 75 projects inside the light shielding cylinder 70. The convex portion 75 functions as a removal preventing portion that prevents the second lens group frame 50 from coming out of the light shielding tube 70 forward, and the front end portion of the second lens group frame 50 abuts on the convex portion 75, thereby The two-lens group frame 50 is prevented from coming out of the light shielding cylinder 70 forward.

The operation of the zoom lens device 1 will be described.
In the retracted state as shown in FIG. 1, the third lens group frame 60 is close to the image sensor 80 side, the cam cylinder 20 and the key ring 30 are drawn into the fixed cylinder 10, and the first lens group frame 40 is The second lens group frame 50 is close to the third lens group frame 60 side and enters the first lens group frame 40 while being drawn into the cam cylinder 20 and the key ring 30. Further, in this retracted state, the second lens group frame 50 enters the front side in the light shielding cylinder 70, and the sliding claw 52 is separated forward from the second stopper 74. Further, in this retracted state, the light shielding cylinder 70 enters the front side in the first lens group frame 40, the sliding pin 42 is separated rearward from the first stopper 72, and the sliding pin 42 is the first guide. It escapes backward from the groove 71.

  When the cam cylinder 20 is rotated by the motor from the state shown in FIG. 1, the cam cylinder 20 is extended forward from the fixed cylinder 10 by the cam cylinder guide groove 11 as shown in FIG. The frame 60 moves forward in conjunction with the cam cylinder 20. At this time, the first lens group frame 40 is extended forward from the cam cylinder 20 and the key ring 30 by the first group lens cam groove 23, and the second lens group frame 50 is moved forward by the second group lens cam groove 24. . Here, the moving distance of the first lens group frame 40 from the retracted state of FIG. 1 to the wide-angle state of FIG. 2 (based on the cam cylinder 20) is the front of the second lens group frame 50. It is larger than the moving distance to (based on the cam cylinder 20). Therefore, when the first lens group frame 40 is extended forward from the retracted state, the slide pin 42 is inserted into the first guide groove 71 and then the slide pin 42 slides forward in the first guide groove 71. Move. When the sliding pin 42 comes into contact with the first stopper 72, the first lens group frame 40 is extended forward, whereby the light shielding cylinder 70 is extended forward from the second lens group frame 50 (see FIG. 2). . Even in the state of FIG. 2, the light shielding cylinder 70 does not come out of the second lens group frame 50 forward.

  In the wide-angle state of FIG. 2, even when the first lens group frame 40 is extended from the second lens group frame 50 to the subject side, the gap between the first lens group frame 40 and the second lens group frame 50 is shielded from light. The cylinder 70 is closed. Therefore, it is possible to prevent the light from going outside the second lens group frame 50 and generating ghost and flare.

  When the cam cylinder 20 is rotated by the motor from the state of FIG. 2, the first lens group frame 40 is slightly pulled back by the first group lens cam groove 23 as shown in FIG. Is moved forward by the second group lens cam groove 24, and the second lens group frame 50 enters the first lens group frame 40. At this time, the light shielding cylinder 70 enters the first lens group frame 40 and the second lens group frame 50 enters the first lens group frame 40 and the light shielding cylinder 70. Specifically, the following two operations or a combination thereof is performed. First, the light blocking cylinder 70 moves forward together with the second lens group frame 50 until the front end of the light blocking cylinder 70 contacts the front end of the first lens group frame 40, and the front end of the light blocking cylinder 70 is the first lens group. When it hits the front end of the frame 40, the light shielding cylinder 70 stops and the second lens group frame 50 enters the light shielding cylinder 70. Second, until the front end of the second lens group frame 50 contacts the convex portion 75 of the light shielding cylinder 70, the second lens group frame 50 enters the light shielding cylinder 70, and the front end of the second lens group frame 50 is convex. When hitting the portion 75, the light shielding cylinder 70 moves forward together with the second lens group frame 50, and the light shielding cylinder 70 and the second lens group frame 50 enter the first lens group frame 40. In addition, when the light shielding cylinder 70 moves forward in the first lens group frame 40, the sliding pin 42 comes back out of the first guide groove 71 (see FIG. 3).

  When the cam cylinder 20 is rotated reversely by the motor from the state of FIG. 3, the first lens group frame 40 is slightly advanced forward by the first group lens cam groove 23 as shown in FIG. The group frame 50 moves rearward by the second group lens cam groove 24, and the second lens group frame 50 comes back out of the first lens group frame 40. At this time, the second lens group frame 50 is pulled out from the light shielding cylinder 70 and the sliding claw 52 slides back in the second guide groove 73. Then, when the sliding claw 52 comes into contact with the second stopper 74, the second lens group frame 50 moves further back, so that the light shielding cylinder 70 is pulled out from the first lens group frame 40 (see FIG. 2). ).

  When the cam cylinder 20 is rotated reversely by the motor from the state of FIG. 2, the cam cylinder 20 is pulled into the fixed cylinder 10 by the cam cylinder guide groove 11 and the third lens group frame 60 as shown in FIG. 1. Moves backward in conjunction with the cam cylinder 20. At this time, the first lens group frame 40 is pulled back into the cam cylinder 20 and the key ring 30 by the first group lens cam groove 23, and the second lens group frame 50 is moved rearward by the second group lens cam groove 24. . At this time, since the sliding claw 52 is engaged with the second stopper 74, the light-shielding cylinder 70 moves rearward when the second lens group frame 50 moves rearward. Also moves backward, so that the light-shielding tube 70 does not come out from the first lens group frame 40 backward. When the front end of the first lens group frame 40 hits the front end of the light shielding cylinder 70, the light shielding cylinder 70 is pushed backward by the first lens group frame 40, and the second lens group frame 50 enters the light shielding cylinder 70. (See FIG. 1).

As described above, according to the present embodiment, it is possible to prevent the occurrence of ghost, flare and the like by the light shielding cylinder 70.
Further, since the light shielding cylinder 70 moves using the movement of the first lens group frame 40 and the second lens group frame 50, a dedicated drive mechanism for driving the light shielding cylinder 70 is not required. Therefore, it is possible to prevent the occurrence of ghosts and flares with a simple structure.

The present invention is not limited to the above embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, in the above embodiment, the lens group 49, 59, 69 forms an image on the image sensor 80, but the image may be formed on a photographic film.
The shapes of the grooves 11, 23, and 24 can be changed as appropriate according to the optical characteristics of the lens groups 49, 59, and 69.

20 Cam cylinder 30 Key ring 40 First lens group frame 42 Slide pin (first slider, first drop prevention portion)
50 Second lens group frame 52 Sliding claw (second slider, second drop prevention portion)
70 light-shielding cylinder 71 first guide groove 72 first stopper (first drop prevention portion)
73 Second guide groove 74 Second stopper (second drop prevention portion)
75 Convex part (third drop prevention part)

Claims (5)

A first lens group frame;
A second lens group frame disposed inside the first lens group frame;
A key ring that is disposed outside the first lens group frame, and that holds the first lens group frame and the second lens group frame movably in the optical axis direction and restricting rotation in the circumferential direction;
The second lens group frame is placed in the first lens group frame by rotating in the circumferential direction with respect to the key ring, and the first lens group frame is disposed outside the key ring. A cam cylinder that moves the first lens group frame and the second lens group frame to a state of being extended from the second lens group frame to the subject side;
Interpolated in the first lens group frame, provided to be slidable in the optical axis direction with respect to the first lens group frame, externally mounted on the second lens group frame, and with respect to the second lens group frame A lens barrel device comprising: a light-shielding tube slidably provided in an optical axis direction. A first slider projecting from one of an inner peripheral surface of the first lens group frame and an outer peripheral surface of the light shielding cylinder;
A first guide groove that is recessed in the other of the inner peripheral surface of the first lens group frame and the outer peripheral surface of the light shielding cylinder, and holds the first slider movably in the optical axis direction;
A second slider projecting from one of the outer peripheral surface of the second lens group frame and the inner peripheral surface of the light shielding tube;
A second guide groove that is recessed in the other of the outer peripheral surface of the second lens group frame and the inner peripheral surface of the light shielding cylinder and holds the second slider movably in the optical axis direction. The lens barrel device according to claim 1, further comprising:   A first omission prevention that is provided between the outer peripheral surface of the light shielding cylinder and the inner peripheral surface of the first lens group frame and prevents the light shielding cylinder from coming out of the first lens group frame toward the image plane. The lens barrel device according to claim 1, further comprising a unit.   Second omission prevention provided between the inner circumferential surface of the light shielding cylinder and the outer circumferential surface of the second lens group frame to prevent the second lens group frame from coming out of the light shielding cylinder toward the image plane. The lens barrel device according to claim 1, further comprising a unit.   The third omission prevention part which is provided in the inner peripheral surface of the said light shielding cylinder, and prevents that the said 2nd lens group frame slips out to the to-be-photographed object side from the said light shielding cylinder is characterized by the above-mentioned. The lens barrel device according to any one of the above.

Images