JP2002040516A - Barrier device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barrier device whose occupancy space is small because the structures of a barrier and a barrier driving part are made simple and in which the miniaturization of a lens barrel incorporating the barrier is attained and also the exchange of the barrier can be easily performed. SOLUTION: The lens barrel 1 incorporating the barrier device possesses a moving frame 2 which holds a photographing lens and moves back and forth, a press ring 4 pressing and holding a first lens 3A attached to the most front surface of the moving frame 2, a driving ring 7 freely rotatably fitted in the outer peripheral surface of the press ring 4 and to drive the barrier so as to open and close, a barrier supporting frame 5 to rotatably support the barrier and barriers 8 and 10, and the driving ring 7 is rotated and driven by linking with the extension of the moving frame 2, and the barriers 8 and 10 are rotated and driven from a lens shielding position to a lens non-shielding position through a barrier driving pin 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a barrier device having a barrier movable between a closed position for covering a lens in front of a lens barrel and an open position retracted from the front surface of the lens.

[0002]

2. Description of the Related Art Conventionally, by covering an opening of a lens in a state where a lens barrel is not used, the lens is protected from dirt intrusion, dirt caused by contact with a finger or the like, and scratches caused by contact with an object. A lens barrel incorporating a barrier (barrier blade) that retracts from the front surface of the lens and is opened is disclosed, for example, in Japanese Patent Application Laid-Open No. Hei 5-19331.

[0003]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 5-193 is disclosed.
In the lens barrel disclosed in Japanese Patent Publication No. 31, the barrier is driven by a rotating ring, and the rotating ring is disposed by being fitted to the inner periphery of the outer lens frame, resulting in a large space. In need. Further, when the barrier breaks down, it is difficult to replace the rotating ring because the rotating ring is housed behind the lens frame.

Further, a rotating pin for opening and closing the barrier penetrates the lens frame, and a rotating ring for driving the rotating pin is disposed behind the lens frame. It's complicated. Further, in order to prevent the rotation pin of the barrier from falling down or the like, it is necessary to bring the barrier and the rotation ring as close as possible. However, when such an arrangement is adopted, the outer mounting portion of the lens frame becomes thin. turn into. If the mounting portion is made thin, there occurs a problem that the strength of the lens frame is insufficient and a predetermined performance of the lens cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has a simple structure of a barrier and a barrier driving unit, occupies a small space, and can reduce the size of a lens barrel in which a barrier is incorporated. It is another object of the present invention to provide a barrier device that can easily replace a barrier.

[0006]

According to a first aspect of the present invention, there is provided a barrier device, comprising: a lens provided on a front surface of a lens barrel; and a movable device which is located on the front surface of the lens and moves in a plane perpendicular to the optical axis of the lens. A barrier that moves between a closed position that covers the lens and an open position that is retracted from the front surface of the lens, a holding member that holds the lens against the lens barrel, and a fitting member that fits into the holding member to open and close the barrier. The barrier is driven to the closed position and the open position by rotation of the drive member.

According to a second aspect of the present invention, there is provided a barrier device comprising: a lens provided on a front surface of a lens barrel; and a closing member which is located on the front surface of the lens and moves in a plane perpendicular to the optical axis of the lens to cover the lens. A barrier that moves to a position and an open position retracted from the front surface of the lens, and a driving member that fits and rotates with the lens to drive the barrier to open and close, and the barrier includes the driving member Is rotated to the closed position and the open position.

According to a third aspect of the present invention, in the barrier device according to the first or second aspect, the lens is movable in the optical axis direction.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a lens barrel in which a barrier device according to a first embodiment of the present invention is incorporated. FIG. 2 is a longitudinal sectional view of the lens barrel, and FIG. 3 is a sectional view taken along line AA of FIG. In the following description, the moving direction of each member along the optical axis is as follows.
The direction toward the lens barrel front cover, which is the subject side, is defined as the front direction, and the direction toward the imaging side is defined as the rear. The rotation direction of each member is indicated by the rotation direction viewed from the front side (the lens barrel front cover side).

The lens barrel 1 having the barrier device according to the first embodiment constitutes a photographic lens, and is provided with a first lens 3A, a second lens 3B, and a second lens 3B sequentially arranged from the subject side toward the image forming side. A third lens 3C, a moving frame 2 that holds each lens and is driven forward and backward along the optical axis of the lens, a pressing ring 4 that is a pressing member for the lens, and a driving ring that is a driving member for rotating the barrier. 7, a barrier support frame 5 as a flange-like member for supporting the barrier, a lens barrel front cover 6, barriers 8 and 10 as upper and lower thin plate-like barrier blades for opening and closing the front surface of the lens, and a fixed frame (not shown) And a pin support plate 15 that is supported by the
And a drive mechanism (not shown) for driving the actuator forward and backward.

The second lens 3B and the third lens 3C are
It is adhered to the moving frame 2 and fixed by caulking. And
The outer diameter portion of the first lens 3A is fitted into the moving frame 2,
It is pressed and held by the holding ring 4.

The moving frame 2 is provided with a flange 2c having an opening into which the first lens 3A fits, and a slope 2f on the back side (rear side) of the flange 2c. The flange 2c has an insertion hole 2a for inserting the holding ring leg and an insertion hole 2b for inserting the drive ring cam.
And a spring suspension pin 2g, and a barrier holding frame and two step portions 2d and 2e into which a lens barrel cover is fitted and mounted are provided on the outer peripheral portion of the flange portion 2c.

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 protrudes rearward in the optical axis O direction. And three legs 4d.

The holding ring 4 is mounted on the moving frame 2 by inserting the leg 4d into the insertion hole 2a of the moving frame 2 and engaging the claw 4c with the slope 2f of the moving frame 2. In the mounted state, the first lens 3A is pressed and held by the ring portion 4b toward the moving frame 2 side. The claw 4c is fixed to the inclined surface 2f of the moving frame 2 by bonding, so that the holding ring 4 does not rotate.

The drive ring 7 has an annular portion 7 having an inner peripheral surface 7a rotatably fitted on the outer peripheral surface 4b of the presser ring 4.
e, two barrier drive pins 7b, a cam portion 7c projecting rearward in the direction of the optical axis O, and a support projection 7 for spring suspension.
d is provided.

The drive ring 7 is attached to the outer peripheral surface 4b of the press ring 4 by rotatably fitting an inner peripheral surface 7a thereof. Further, the driving ring biasing spring 12 is connected to the spring suspension projection 7.
d and a spring suspension pin 2 g of the moving frame 2,
The drive ring 7 is urged clockwise. In the mounted state, the cam portion 7c is inserted through the insertion hole 2b of the moving frame 2,
It is in a state where it can abut on the drive ring drive pin 16. on the other hand,,
The barrier drive pin 7 b is inserted into the elongated hole 5 f of the barrier support frame 5, protrudes from the front surface of the barrier support frame 5, and can contact the bottom surfaces of the barriers 8 and 10.

The barrier support frame 5 includes a lens opening 5a for the first lens 3A in the flange-shaped disk portion, a boss-shaped barrier support pin 5b into which the barriers 8 and 10 are rotatably fitted, and a barrier. 8, 10 closed position stoppers 5c;
Spring mounting pin 5d for mounting barrier springs 9, 11
And a spring contact pin 5e with which one end of the barrier springs 9 and 11 abut, and a long hole 5f through which the barrier drive pin 7b is inserted. The pin 5b, the stopper 5c, the spring support pin 5d, the spring contact pin 5e, and the long hole 5f are provided in a pair at left and right point symmetric positions.

The barrier support frame 5 has a state in which the barrier drive pin 7b of the drive ring 7 is inserted into the elongated hole 5f.
And is fixedly attached. In the mounted state, the drive ring 7 is sandwiched 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
Regulate and hold direction.

The barriers 8, 10 are thin plate members capable of opening and closing the lens opening 5a of the barrier support frame 5, and include support holes 8a, 10a, spring contact portions 8b, 10b, respectively.
Notch 8 that can contact stopper 5c of barrier support frame 5
c and 10c.

The barriers 8 and 10 are fitted in such a manner that the support holes 8a and 10a are fitted into the barrier support pins 5b of the barrier support frame 5 and are rotatable in a plane orthogonal to the optical axis O. Also, the spring support pins 5d of the barrier support frame 5
Barrier biasing springs 9 and 11 for torsion springs mounted on
Is made to abut against the spring contact portions 8b and 10b of the barriers 8 and 10, respectively, to urge the barriers 8 and 10 clockwise in the closed position direction.

As the rotational urging torque acting on the barriers 8 and 10, the counterclockwise urging torque in the barrier opening direction by the driving ring urging spring 12 acting via the barrier driving pin 7b is equal to the barrier urging torque. It is assumed that it is larger than the clockwise urging torque by the urging springs 9 and 11. Therefore, the barriers 8 and 10 are driven to rotate following the rotation of the drive ring 7.

The lens barrel front cover 6 has a lens opening 6a at the center, and is fixedly attached to the movable frame 2 while being fitted into the step 2e of the moving frame 2. The barriers 8, 10, and The barrier urging springs 9 and 11 are held in a state where the direction of the optical axis O is regulated by sandwiching the barrier urging springs 9 and 11 with the barrier support frame 5.

Referring to FIGS. 3 and 4, a description will be given of the opening / closing drive of the barrier associated with the forward / backward movement of the moving frame 2 of the lens barrel 1 configured as described above. Note that FIG.
3 is a barrier opening / closing operation diagram showing an AA cross section of FIG. 2;
FIG. 4 is a side view showing the driven state of the cam portion of the drive ring by the drive ring drive pin.

When the lens barrel 1 is in the housed state, the moving frame 2 is retracted to the rear housed 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 moved counterclockwise to the position where the barrier is closed. It is spinning. That is, as shown in FIG. 3, the barrier driving pin 7 b is slightly separated from the bottom surfaces of the barriers 8 and 10 by the counterclockwise rotation of the driving ring 7, so that the barriers 8 and 10 are biased by the barrier springs 9 and 11. Rotating clockwise, the notches 8c and 10c abut against the stopper 5c of the barrier support frame 5 to close the lens openings 5a (closed positions) P8A and P8.
At 10A.

To set the lens barrel 1 in a photographable state, the moving frame 2 is extended forward. 4, the cam portion 7c of the driving ring 7 also moves forward and separates from the driving ring driving pin 16 as shown in FIG. 4, so that the driving ring 7 is pressed by the urging force of the driving ring urging spring 12. 4 rotates clockwise around the outer periphery of the barrier support frame 5.
Abuts the end of the long hole 5f. Due to the rotation, the barrier drive pin 7b of the drive ring 7 presses against the bottom surfaces of the barriers 8, 10 against the biasing force of the barrier biasing springs 9, 11, and the barriers 8, 10 are in the opening direction in the counterclockwise direction. Driven around. Then, it rotates to 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 photographable state.

When the lens barrel 1 is to be stored again, the moving frame 2 is moved backward to the storage position. In 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
Since the pressing force of the barrier drive pin 7b is released, the urging force of the barrier urging springs 9 and 11 causes the closing position P8 shown in FIG.
A, rotate to P10A.

According to the barrier device for the lens barrel 1 of the first embodiment described above, the barriers 8 and 10 are automatically closed in response to the forward and backward movement of the moving frame 2 and the closed position where the front surface of the lens is retracted. It can be driven to a position, improving usability.

In the lens barrel 1, since the thickness of the flange of the barrier support frame 5 can be reduced to shorten the barrier drive pin 7b of the drive ring 7, the barrier drive pin 7b
The barrier does not collapse or deform, and the barrier can be opened and closed with high accuracy.

As described above, each member of the barrier device is connected to the optical axis O.
Can be stored in the minimum space in the direction. 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.

The optical path diagram of FIG. 5 shows the optical path of the photographing light passing through the first lens 3A disposed at the forefront with respect to the film surface 19. The barrier needs to be retracted so as not to kick the outermost photographing light L0 of the photographing light. Therefore, as described above, the lens opening 5a
Is very close to the first lens 3A, the opening width D1 of the barriers 8, 10 is smaller than the opening width D2 of the barriers 8 ', 10' when the lens openings are farther away. As described above, in the barrier device to which the barriers 8 and 10 are applied, the arrangement space in the direction orthogonal to the optical axis O can be said to be small.

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 in the optical axis O, so that the lens barrel 1 can be made compact and compact.

Further, the drive ring 7 can be made compact because the sliding fitting portion is the outer diameter of the press ring 4. At the same time, since the sliding fitting portion is fitted with a small diameter, the friction load on the drive ring 7 can be small, and a smooth operation can be obtained.

The holding ring 4 is engaged with the moving frame 2 by the claw 4c of the leg 4d extending through the flange 2c of the moving frame 2, and the engaging portion is bonded and fixed. The agent does not move around the fitting surface of the drive ring 7 to cause a malfunction.

Further, since the main components such as the barrier are located in front of the movable frame 2, the barrier mechanism can be replaced very easily when the components such as the barrier are replaced due to failure.

In the pressing ring 4 of the lens barrel 1 of the first embodiment, the outer peripheral surface into which the driving ring 7 is rotatably fitted is formed by a mere full circular surface. As a modification, FIG.
Can be proposed.

The holding ring 18 of the above-described modified example includes the driving ring 7
Gives a circumferential trajectory as an outer peripheral surface into which the rotatably fits 3
A plurality of convex fitting portions 18b are provided. Others
An annular portion 18e having an opening 18a like the holding ring 4,
3 protruding rearward in the optical axis O direction and having a claw portion 18c
There are provided two legs 18d and the like.

When the holding ring 18 of this modification is applied, the fitting portion of the holding ring 18 with the driving ring is made of three convex fitting portions 18b. The play of the fitting with the ring 7 can be easily adjusted on the mold, and the fitting accuracy can be improved. Therefore, the drive ring 7 is rotatably fitted to the holding ring 18 with little backlash, and a highly accurate barrier opening / closing operation can be obtained. Further, since the legs 18d of the holding ring 18 are arranged at the positions where the three convex fitting portions 18b are provided, even if a load is applied from the driving ring 7, the holding ring 18 is hardly twisted,
In addition, the adhesive is not peeled off at the claw portion 18c.

Next, a lens barrel incorporating a barrier device according to a second embodiment of the present invention 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 includes a first lens 3A ', a second lens 3B, and a third lens 3C which are sequentially arranged from the subject side to the image forming side.
A moving frame 2 that holds the lenses and is driven forward and backward along the optical axis of the lens, a driving ring 22 that is a driving member for driving the rotation of the barrier, and a barrier supporting frame that is a flange-shaped member that supports the barrier 23, a front lens barrel cover 6, two upper and lower thin blade-shaped barriers 8 and 10 for opening and closing the front surface of the lens, and a pin support that is held by a fixed frame (not shown) and supports the drive ring drive pin 16. It has a plate 15 (not shown), a drive mechanism (not shown) for driving the moving frame 2 forward and backward, and the like.
The second and third lenses 3B and 3C and the moving frame 2
The barriers 8, 10 and the front lens barrel cover 6 are the same members as those applied to the first embodiment.

The first lens 3A 'is fixed to the front surface of the moving frame 2 by bonding or the like. And the first lens 3
An outer peripheral surface 3Aa 'on which the drive ring 22 is rotatably fitted is provided on the front side exposed portion of A'.

The drive ring 22 has an inner peripheral surface 22a rotatably fitted to the outer peripheral surface 3A'a of the first lens 3A '. Otherwise, the drive ring 7 has the same shape.

The barrier support frame 23 is provided with the lens opening 2
It has a convex flat portion 22g for mounting the barrier provided with 3a and a driving ring pressing flat portion 23h. In addition, barrier support pins, spring support pins, and the like are provided similarly to the barrier support frame 5.

The drive ring 22 is rotatably fitted on the outer peripheral surface 3A'a of the first lens 3A ', and is slidable with the direction of the optical axis O regulated by the drive ring pressing surface 23h of the barrier support frame 23. Is held.

The opening / closing operation of the barrier in the lens barrel 21 of the present embodiment having the above-described structure according to the movement of the moving frame 2 is similar to that of the lens barrel 1 of the first embodiment. The opening and closing driving of the barriers 8 and 10 is performed in accordance with the forward and backward driving of the moving frame 2.

According to the barrier device for the lens barrel 21 of the second embodiment described above, the same effect as that of the first embodiment can be obtained, and in particular, a dedicated press for pressing the lens against the moving frame 2. Barriers 8, 1 because ring 4 is not required
0 can be arranged 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 optical axis O direction and the direction orthogonal to the optical axis O can be reduced, and the lens barrel can be made more compact, and the assembly becomes easier.

According to the above-described embodiment of the present invention, (1) an opening shielding position which is 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 which blocks the opening of the lens; A barrier blade that can be moved to an opening non-blocking position that does not block the opening, a holding ring that fixes and holds at least the frontmost lens ball to the lens frame, and is fitted around the holding ring and rotates around the lens optical axis. Accordingly, it is possible to propose a barrier device comprising a drive ring for moving the outer barrier blade to the above-mentioned opening shielding position and the above-mentioned opening non-shielding position.

(2) The holding ring has 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 above item (1) can be proposed.

(3) The barrier device according to the above item (1), wherein the fitting portion of the press ring with the drive ring is formed of a plurality of convex surfaces.

(4) 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 retracted to an opening blocking position for blocking the opening of the lens and an opening non-blocking position for not blocking the opening. A possible barrier blade, at least disposed on the frontmost surface, having a fitting portion on the outer periphery, a lens fixed to the lens frame, fitted into the fitting portion of the lens, and rotated around the lens optical axis And a driving ring for moving the barrier blade to the above-mentioned opening shielding position and the opening non-shielding position.

(5) The barrier blade is rotatably fitted to a boss provided on a flange-like member fixed to the front portion of the lens frame. (1) or being biased to move to the shielding position, or
The barrier device described in the item (2) can be proposed.

[0050]

As described above, according to the present invention, the structure of the barrier and the barrier drive section is simple, the occupied space is small, the lens barrel in which the barrier is incorporated can be downsized, and the barrier can be replaced. A barrier device that can be easily performed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lens barrel in which a barrier device according to a first embodiment of the present invention is incorporated.

FIG. 2 is a longitudinal sectional view of the lens barrel according to the first embodiment.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, showing an opening / closing operation state of a 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 according to the first embodiment.

FIG. 6 is a perspective view of a modified example of a holding ring applied to the lens barrel according to 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 ': First lens (lens in front of lens barrel) 4, 18 ... Pressing ring (pressing member) 7, 22: Drive ring (driving member) 8, 10: Barrier P8A, P10A … Barrier closed position (closed position covering the lens) P8B, P10B …… Barrier open position (opened position retracted from the lens)

Claims (3)

[Claims] 1. A lens in front of a lens barrel, a closed position that is located in front of the lens and moves in a plane perpendicular to the optical axis of the lens to cover the lens, and an open position that is retracted from the front of the lens. And a pressing member that presses the lens against the lens barrel; and a driving member that fits and rotates with the pressing member to drive the barrier to open and close. Barrier device. 2. A lens located in front of a lens barrel, a closed position located in front of the lens and moved in a plane perpendicular to the optical axis of the lens to cover the lens, and an open position retracted from the front of the lens. And a driving member that fits and rotates with the lens to drive the barrier to open and close. 3. The barrier device according to claim 1, wherein the lens of the barrier device according to claim 1 is movable in an optical axis direction.