JP4468556B2 - Barrier device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a barrier device having a barrier movable between a closed position that covers a lens on the front surface of a lens barrel and an open position that is retracted from the front surface of the lens.
[0002]
[Prior art]
Conventionally, by covering the lens opening when the lens barrel is not in use, the lens is protected from dirt intrusion, dirt due to finger contact, scratches due to contact with objects, etc. For example, Japanese Patent Laid-Open No. 5-19331 discloses a lens barrel in which a barrier (barrier blade) that is retracted to be opened is incorporated.
[0003]
[Problems to be solved by the invention]
In the lens barrel disclosed in Japanese Patent Laid-Open No. 5-19331, the barrier is driven by a rotating ring, and the rotating ring is fitted to the inner periphery of the outer lens frame. As a result, a large space is required. Further, when the barrier breaks down, it is difficult to replace the rotating ring because the rotating ring is housed behind the lens frame.
[0004]
In addition, a rotation pin for opening and closing the barrier penetrates the lens frame, and a rotation ring for driving the rotation pin is disposed behind the lens frame, so that the structure of the lens frame becomes complicated. ing. Further, in order to prevent the rotating pin of the barrier from collapsing, it is necessary to bring the barrier and the rotating ring as close as possible, but with such an arrangement, the mounting portion outside the lens frame becomes thin. turn into. If the mounting portion is made thin, the lens frame is insufficient in strength, causing problems such as failure to obtain a predetermined performance of the lens.
[0005]
The present invention has been made in order to solve the above-described problems. The structure of the barrier and the barrier driving unit is simple, the occupied space is small, and the lens barrel in which the barrier is incorporated can be downsized. An object of the present invention is to provide a barrier device that can be easily replaced.
[0006]
[Means for Solving the Problems]
The first barrier device of the present invention includes a lens on the front surface of the lens barrel, a closed position that is positioned in front of the lens and moves in a plane perpendicular to the lens optical axis to cover the lens, and the front surface of the lens. And a driving member that fits and rotates with the lens to drive the opening and closing of the barrier .
[0008]
According to a second barrier device of the present invention, in the first barrier device, the lens is movable in the optical axis direction.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view of a lens barrel in which a barrier device showing a first embodiment of the present invention is incorporated. FIG. 2 is a longitudinal sectional view of the lens barrel, and FIG. 3 is an AA sectional view of FIG. In the following description, as the advancing / retreating direction along the optical axis of each member, the lens barrel front cover side direction which is the subject side is the front direction, and the imaging side direction is the rear side. Moreover, the rotation direction of each member is shown by the rotation direction seen from the front side (lens barrel front cover side).
[0010]
The lens barrel 1 having the barrier device of the first embodiment constitutes a photographic lens, and is arranged in order from the subject side toward the imaging side, the first lens 3A, the second lens 3B, and the third lens. 3C, a moving frame 2 that holds each lens and is driven forward and backward along the lens optical axis, a pressing ring 4 that is a pressing member of the lens, and a driving ring 7 that is a driving member for barrier rotation driving, A barrier support frame 5 that is a flange-like member that supports the barrier, a lens barrel front cover 6, barriers 8 and 10 that are two thin plate-like barrier blades for opening and closing the lens front surface, and a fixed frame (not shown). And a pin support plate 15 for supporting the drive ring drive pin 16 and a drive mechanism (not shown) for driving the moving frame 2 forward and backward.
[0011]
The second lens 3B and the third lens 3C are bonded to the moving frame 2 and fixed by caulking. The first lens 3 </ b> A is inserted into the moving frame 2 and held by being pressed by the pressing ring 4.
[0012]
The moving frame 2 is provided with a flange portion 2c having an opening into which the first lens 3A is fitted, and a slope portion 2f on the back side (rear side) of the flange portion 2c. The flange portion 2c is provided with an insertion hole 2a for inserting the presser ring leg portion, an insertion hole 2b for inserting the drive ring cam portion, and a spring suspension pin 2g, and the outer periphery of the flange portion 2c. The part is provided with a barrier holding frame and two step portions 2d and 2e into which a lens barrel cover is fitted and attached.
[0013]
The holding ring 4 is provided with an annular portion 4e having an opening 4a for the first lens 3A, an outer peripheral surface 4b, and a claw portion 4c at the tip, and three protruding toward the rear in the optical axis O direction. Legs 4d are provided.
[0014]
The presser ring 4 is attached to the moving frame 2 by inserting the leg portion 4 d through the insertion hole 2 a of the moving frame 2 and engaging the claw portion 4 c with the inclined surface portion 2 f of the moving frame 2. In this mounted state, the first lens 3A is pressed and held on the moving frame 2 side by the annular portion 4b. The claw portion 4c is fixed to the slope portion 2f of the moving frame 2 by adhesion so that the pressing ring 4 does not rotate.
[0015]
The drive ring 7 has an annular portion 7e having an inner peripheral surface 7a that is rotatably fitted on the outer peripheral surface 4b of the pressing ring 4, two barrier drive pins 7b, and the rear in the optical axis O direction. A protruding cam portion 7c and a spring suspension support projection 7d are provided.
[0016]
The drive ring 7 is attached to the outer peripheral surface 4b of the pressing ring 4 by fitting the inner peripheral surface 7a in a rotatable manner. A drive ring biasing spring 12 is suspended from the spring suspension projection 7d and the spring suspension pin 2g of the moving frame 2 to urge the drive ring 7 clockwise. In the attached state, the cam portion 7 c is inserted through the insertion hole 2 b of the moving frame 2 and is in a state where it can contact the drive ring drive pin 16. On the other hand, the barrier drive pin 7 b passes through the long hole 5 f of the barrier support frame 5 and protrudes from the front surface of the barrier support frame 5 so as to be able to contact the bottom surfaces of the barriers 8 and 10.
[0017]
The barrier support frame 5 has a lens opening 5a for the first lens 3A, a boss-like barrier support pin 5b into which the barriers 8 and 10 are rotatably fitted, and barriers 8 and 10 in the flange-like disk portion. Closed position stopper 5c, a spring mounting pin 5d for mounting the barrier springs 9 and 11, a spring contact pin 5e for contact with one end of the barrier springs 9 and 11, and a long hole 5f through which the barrier drive pin 7b is inserted. ing. A pair of the pin 5b, the stopper 5c, the spring support pin 5d, the spring contact pin 5e, and the elongated hole 5f are provided at left and right point symmetrical positions.
[0018]
The barrier support frame 5 is attached in a state where the barrier drive pins 7b of the drive ring 7 are inserted into the elongated holes 5f, fitted into the step 2d of the movable frame 2, and fixed. In the attached state, the drive ring 7 is held between the front surface of the flange portion 2c of the moving frame 2 and the rear inner surface of the barrier support frame 5, and the optical axis O direction is regulated and held.
[0019]
The barriers 8 and 10 are thin plate members capable of opening and closing the lens opening 5a of the barrier support frame 5, and are respectively provided with support holes 8a and 10a, spring contact portions 8b and 10b, and a stopper 5c of the barrier support frame 5. Cutouts 8c and 10c that can abut are provided.
[0020]
The barriers 8 and 10 are attached so that the support holes 8a and 10a are fitted into the barrier support pins 5b of the barrier support frame 5 and can be rotated in a plane orthogonal to the optical axis O, respectively. Further, one end of the barrier urging springs 9 and 11 of the torsion spring mounted on the spring support pin 5d of the barrier support frame 5 is brought into contact with the spring contact portions 8b and 10b of the barriers 8 and 10, and the barriers 8 and 10 are attached. Each is biased clockwise, which is the direction of the closed position.
[0021]
Incidentally, as the rotational biasing torque acting on the barriers 8 and 10, the counterclockwise biasing torque in the barrier opening direction by the drive ring biasing spring 12 acting via the barrier drive pin 7b is the barrier biasing spring. It is assumed that it is larger than the clockwise energizing torque of 9,11. Therefore, the barriers 8 and 10 are driven to rotate following the rotation of the drive ring 7.
[0022]
The lens barrel front cover 6 has a lens opening 6a at the center, and is fixedly attached in a state of being fitted into the step 2e of the moving frame 2, and the barriers 8, 10 and the barrier biasing force. The springs 9 and 11 are held between the barrier support frame 5 and held in a state in which the direction of the optical axis O is regulated.
[0023]
The barrier opening / closing drive accompanying the forward / backward movement of the moving frame 2 of the lens barrel 1 of the present embodiment configured as described above will be described with reference to FIGS. 3 is a barrier opening / closing operation diagram showing the AA cross section of FIG. 2, and FIG. 4 is a side view showing the driven state of the cam portion of the drive ring by the drive ring drive pin.
[0024]
When the lens barrel 1 is in the storage state, the moving frame 2 is retracted to the rear storage position. In this state, the drive ring 7 is similarly retracted, and the cam portion 7c is in contact with the drive ring drive pin 16 as shown in FIG. 4, and the drive ring 7 is counterclockwise to the position where the barrier is closed. It is rotating. That is, as shown in FIG. 3, the barrier drive pin 7 b is slightly separated from the bottom surfaces of the barriers 8, 10 by the counterclockwise rotation of the drive ring 7, so that the barriers 8, 10 are biased by the barrier springs 9, 11. By rotating clockwise, the notches 8c and 10c abut against the stopper 5c of the barrier support frame 5 and are at closed positions (shielding positions) P8A and P10A covering the lens opening 5a.
[0025]
In order to set the lens barrel 1 in the photographing enabled state, the moving frame 2 is extended forward. 4, the cam portion 7c of the drive ring 7 moves forward and separates from the drive ring drive pin 16 as shown in FIG. 4, so that the drive ring 7 is pressed by the urging force of the drive ring urging spring 12. 4, the barrier drive pin 7 b comes into contact with the end of the long hole 5 f of the barrier support frame 5. The rotating operation causes the barrier drive pin 7b of the drive ring 7 to press the bottom surfaces of the barriers 8 and 10 against the urging force of the barrier urging springs 9 and 11, and the barriers 8 and 10 are counterclockwise in the opening direction. Driven around. And it rotates to the open positions (non-shielding positions) P8B and P10B retracted from the front surface of the first lens 3C. In this state, the lens barrel 1 is set in a photographing enabled state.
[0026]
When the lens barrel 1 is to be stored again, the moving frame 2 is moved backward to the storage position. By this retraction operation, the drive ring 7 is driven to rotate counterclockwise by the drive ring drive pin 16 and the barriers 8 and 10 are released from the pressure of the barrier drive pin 7b. As a result, it rotates to the closed positions P8A and P10A shown in FIG.
[0027]
According to the barrier device for the lens barrel 1 of the first embodiment described above, the barriers 8 and 10 are automatically driven to the closed position that covers the front surface of the lens and the retracted open position in conjunction with the forward and backward movement of the moving frame 2. It is possible to make it easier to use.
[0028]
Further, in the lens barrel 1, since the thickness of the flange of the barrier support frame 5 can be reduced and the barrier drive pin 7b of the drive ring 7 can be shortened, the barrier drive pin 7b does not fall down or deform, High-precision opening / closing operation of the barrier can be obtained.
[0029]
As described above, each member of the barrier device can be stored in the minimum space in the optical axis O direction. Also in the direction orthogonal to the optical axis O, as shown in FIG. 2, the lens opening 5a of the barrier support frame 5 is provided very close to the front surface of the first lens 3A. Space can be reduced.
[0030]
The optical path diagram of FIG. 5 shows the optical path of the photographing light passing through the first lens 3 </ b> A that is disposed in front of the film surface 19. The barrier needs to be retracted so as not to kick the outermost photographing light L0 out of the photographing light. Therefore, as described above, the opening width D1 of the barriers 8 and 10 when the lens opening 5a is very close to the first lens 3A is equal to the barriers 8 'and 10' when the lens opening is farther. Therefore, it can be said that the barrier device to which the barriers 8 and 10 are applied as described above has a smaller arrangement space in the direction orthogonal to the optical axis O.
[0031]
As described above, the space occupied by the barrier device can be reduced in the direction orthogonal to the optical axis O as well as the direction of the optical axis O, so that the lens barrel 1 can be made compact and downsized.
[0032]
Further, the drive ring 7 can be reduced in size because the sliding fitting portion is the outer diameter portion of the pressing ring 4. At the same time, since the sliding fitting portion is fitted with a small diameter, the friction load of the drive ring 7 can be reduced, and a smooth operation can be obtained.
[0033]
The holding ring 4 is engaged with the moving frame 2 by the claw 4c of the leg portion 4d extending through the flange portion 2c of the moving frame 2, and the engaging portion is bonded and fixed, so that the applied adhesive is driven. It does not cause a malfunctioning state around the fitting surface of the ring 7.
[0034]
Furthermore, since the main structural member such as the barrier is in front of the moving frame 2, the barrier mechanism can be replaced very easily when the structural member such as the barrier is broken and replaced.
[0035]
In the holding ring 4 of the lens barrel 1 according to the first embodiment, the outer peripheral surface into which the drive ring 7 is rotatably inserted is formed as a simple entire peripheral surface. Can be proposed.
[0036]
The pressing ring 18 of the above-described modification is provided with three convex fitting portions 18b that provide a circumferential locus as an outer peripheral surface into which the driving ring 7 is rotatably fitted. Others are provided with an annular portion 18e having an opening 18a as in the case of the presser ring 4, and three leg portions 18d having a claw portion 18c protruding rearward in the optical axis O direction.
[0037]
When the pressing ring 18 of this modification is applied, since the fitting portion of the pressing ring 18 with the driving ring is made into three convex fitting portions 18b, when the pressing ring is manufactured by resin molding, The fitting backlash can be easily adjusted on the mold, and the fitting accuracy can be improved. Therefore, the drive ring 7 can be rotatably fitted to the holding ring 18 with little play, and an accurate opening / closing operation of the barrier can be obtained. Further, since the leg portion 18d of the pressing ring 18 is disposed at a position where the three convex fitting portions 18b are provided, even if a load is applied from the driving ring 7, the pressing ring 18 is less likely to be twisted, and the claw portion 18c. The adhesive will not peel off.
[0038]
Next, a lens barrel in which the barrier device according to the second embodiment of the present invention is incorporated will be described with reference to a longitudinal sectional view of the lens barrel in FIG.
As shown in FIG. 7, the lens barrel 21 holds the first lens 3A ′, the second lens 3B, the third lens 3C, which are sequentially arranged from the subject side to the image forming side, and the lenses. A moving frame 2 that is driven back and forth along the optical axis, a driving ring 22 that is a driving member for barrier rotation driving, a barrier support frame 23 that is a flange-like member that supports the barrier, a lens barrel front cover 6, Upper and lower thin blade-like barriers 8 and 10 for opening and closing the lens front surface, a pin support plate 15 (not shown) that is held by a fixed frame (not shown) and supports the drive ring drive pin 16, and the above It has a drive mechanism (not shown) for driving the moving frame 2 forward and backward. The second and third lenses 3B and 3C, the moving frame 2, the barriers 8 and 10, and the lens barrel front cover 6 are the same members as those applied to the first embodiment.
[0039]
The first lens 3A ′ is fixed to the front surface of the moving frame 2 by adhesion or the like. An outer peripheral surface 3Aa ′ into which the drive ring 22 is rotatably inserted is provided in the front side exposed portion of the first lens 3A ′.
[0040]
The drive ring 22 has an inner peripheral surface 22a that is rotatably fitted to the outer peripheral surface 3A'a of the first lens 3A '. The other shapes are the same as those of the drive ring 7.
[0041]
The barrier support frame 23 has a convex flat surface portion 22g for attaching a barrier and a driving ring pressing flat surface portion 23h in which a lens opening 23a is provided. In addition, barrier support pins, spring support pins, and the like are provided in the same manner as the barrier support frame 5.
[0042]
The drive ring 22 is rotatably fitted on the outer peripheral surface 3A′a of the first lens 3A ′, and the direction of the optical axis O is regulated by the drive ring pressing surface 23h of the barrier support frame 23 so as to be slidably held. Yes.
[0043]
The opening / closing operation of the barrier accompanying the forward / backward movement of the moving frame 2 in the lens barrel 21 of the present embodiment having the above-described configuration is the same as that of the lens barrel 1 of the first embodiment. The opening / closing drive of the barriers 8 and 10 is performed in accordance with the advance / retreat drive 2.
[0044]
According to the barrier device for the lens barrel 21 of the second embodiment described above, the same effect as in the case of the first embodiment is obtained, and in particular, the dedicated presser ring 4 for pressing the lens against the moving frame 2 is provided. Since it is not necessary, the barriers 8 and 10 can be arranged at positions very close to the first lens 3A ′, and at the same time, the outer diameter of the drive ring 22 can be reduced. Therefore, the space occupied by the barrier device in the direction of the optical axis O and in the direction orthogonal to the optical axis O can be reduced, and the lens barrel can be made more compact and can be easily assembled.
[0045]
According to the embodiment of the present invention described above,
(1) A barrier provided at the front of the lens frame so as to be movable with respect to the lens frame in a plane perpendicular to the lens optical axis, and movable to an opening shielding position that shields the opening of the lens and an opening non-shielding position that does not shield the opening Feathers,
A holding ring that holds and holds at least the foremost lens ball on the lens frame;
A driving ring that moves the outer barrier blade to the opening shielding position and the opening non-shielding position by fitting around the outer periphery of the presser ring and rotating around the lens optical axis;
It is possible to propose a barrier device characterized by comprising:
[0046]
(2) The press ring includes a leg portion that penetrates a notch provided in a flange portion on the front surface of the lens frame and engages with an engagement portion provided behind the flange portion. The barrier device described in the item (1) can be proposed.
[0047]
(3) The barrier device according to the above item (1) can be proposed, wherein the fitting portion of the presser ring with the drive ring is formed by a plurality of convex surfaces.
[0048]
(4) A barrier provided at the front of the lens frame so as to be movable with respect to the lens frame in a plane perpendicular to the lens optical axis and retractable to an opening shielding position that shields the lens opening and an opening non-shielding position that does not shield the opening. Feathers,
A lens disposed at least on the forefront, having a fitting portion on the outer periphery, and fixed to the lens frame;
A drive ring that moves the barrier blade to the opening shielding position and the opening non-shielding position by fitting the fitting portion of the lens and rotating around the lens optical axis;
It is possible to propose a barrier device characterized by comprising:
[0049]
(5) The barrier blade is rotatably fitted to a boss provided on a flange-shaped member fixed to the front portion of the lens frame, and the barrier blade is moved to an opening shielding position or an opening non-shielding position by a spring member. It is possible to propose the barrier device according to the above item (1) or (2), which is biased to move.
[0050]
【The invention's effect】
As described above, according to the present invention, the structure of the barrier and the barrier driving unit is simple, the occupied space is small, the lens barrel in which the barrier is incorporated can be downsized, and the barrier can be easily replaced. An apparatus can be provided.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a lens barrel incorporating a barrier device according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the lens barrel of the first embodiment.
FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2 and shows an opening / closing operation state of the barrier.
FIG. 4 is a side view showing a driven state of a cam portion of a drive ring applied to the lens barrel of the first embodiment with a drive ring drive pin.
FIG. 5 is an optical path diagram of photographing light in the lens barrel of the first embodiment.
FIG. 6 is a perspective view of a modified example of a press ring applied to the lens barrel of the first embodiment.
FIG. 7 is a longitudinal sectional view of a lens barrel in which a barrier device according to a second embodiment of the present invention is incorporated.
[Explanation of symbols]
3A, 3A '... 1st lens (lens in front of lens barrel)
4,18 ...... Presser ring (pressing member)
7, 22 ... Drive ring (drive member)
8, 10: Barrier P8A, P10A: Barrier closed position (closed position covering the lens)
P8B, P10B ...... Barrier open position (open position retracted from lens)

Claims (2)

A lens in front of the lens barrel;
A barrier that is positioned in front of the lens and moves in a plane perpendicular to the lens optical axis to cover the lens and an open position retracted from the lens front;
A drive member that fits and rotates with the lens to drive the barrier to open and close ;
A barrier device comprising: 2. The barrier device according to claim 1, wherein the lens of the barrier device according to claim 1 is movable in the optical axis direction .

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