JP4411717B2 - Lens barrier unit for cameras - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera, and more particularly to a camera lens barrier unit that can be opened and closed on the front side of a camera lens to protect the taking lens. It relates to a lens barrier unit that can be used.
[0002]
[Prior art]
Some lens barrier units use the rotational force of the cam ring of the lens barrel as a drive source. In this case, the lens barrier unit is located between the base plate and the drive plate between the base plate and the drive plate, and the ring base plate that is fixed to the rectilinear cylinder, the ring-type drive plate that is rotatable with respect to the base plate, and is freely openable and closable. The barrier blade mounted on the lens is arranged in a superimposed manner, and the opening of the lens barrier unit is opened and closed by the rotation of the barrier blade.
[0003]
In the above configuration, the base plate is an approximately ring-shaped ring body, and an opening is formed at the center. The ring body is formed with a first attachment portion for pivotally mounting the barrier blade so as to be opened and closed. Similar to the base plate, the drive plate is a ring body having a substantially ring shape, and is configured to engage with the cam ring and transmit the rotational force of the cam ring.
[0004]
In such a configuration, when the cam ring rotates to rotate the drive plate around the optical axis, the rotational driving force of the drive plate is transmitted to each barrier blade to open and close the barrier blade. The barrier blade is engaged with the drive plate. That is, the barrier blade is pressed against the drive plate by the spring force of the spring member. The reason why the spring member is used is that when a foreign object is bitten between the barrier blades, the spring material works as a safety device and absorbs the rotational driving force of the driving plate.
[0005]
In the lens barrier unit configured as described above, a tension coil spring is used as a spring member that presses the barrier blade against the drive plate. The tension coil spring has a certain length in the longitudinal direction, and requires a large storage space in a plane perpendicular to the optical axis in order to expand and contract. On the other hand, the barrier blade moves in a radial direction perpendicular to the optical axis. Therefore, if the tension coil spring is housed in a space sandwiched between the drive plate and the base plate and extending along the plane in which the barrier blades move in the direction perpendicular to the optical axis, the lens barrier unit becomes large. turn into. In particular, in a small camera using a three-component high-power zoom lens, the front lens is large, so that the lens blade unit needs to be small while keeping the barrier blades wide open. If a tension coil spring that requires a large storage space is used for a lens barrier unit having a large opening, the lens barrier unit becomes large. In addition, if the tension coil spring is disposed so as to extend in the optical axis direction, the lens barrier unit becomes thick. In any case, if a tension coil spring is used as a driving force transmission means between the driving plate and the barrier blade, the lens barrier unit becomes large.
[0006]
[Problems to be solved by the invention]
Therefore, the technical problem to be solved by the present invention is to improve the driving force transmitting means for linking the driving plate and the barrier blades to transmit the driving force of the driving plate to the barrier blades. It is an object to provide a lens barrier unit for a camera that can have a large opening despite being present.
[0007]
[Means / Actions / Effects to Solve Problems]
In order to solve the above technical problem, the present invention is characterized in that a torsion coil spring is used as a driving force transmitting means between a driving plate and a barrier blade in a camera lens barrier unit.
[0008]
That is, a camera lens barrier unit according to the present invention is attached to a front end portion of a lens barrel, has a ring-shaped base plate having an opening portion, and has an opening portion at least in a portion facing the opening portion. A drive plate that is rotatable with respect to the base plate and the base plate and the drive plate, and is pivotally attached to a first attachment portion disposed on the base plate so as to open and close the opening of the base plate. A camera lens barrier unit configured to open and close the opening of the base plate by rotating the drive plate around the optical axis. A second mounting portion separate from the first mounting portion is located at a predetermined position on the base plate. The coil portion of the torsion coil spring is formed on the second mounting portion in the optical axis direction. Around the axis parallel to The first arm portion of the torsion coil spring is connected to the drive plate, while the second arm portion is connected to the barrier blade. By The rotational driving force of the drive plate is transmitted to each barrier blade via each torsion coil spring. And a region where the torsion angle of the torsion coil spring hardly changes is provided between the open state and the closed state of the barrier blade. It is characterized by that.
[0009]
The second mounting portion to which the torsion coil spring is pivotally attached is formed at a predetermined position of the base plate separately from the first attachment portion to which the barrier blade is pivotally attached. The torsion coil spring is a normal torsion coil spring in the optical axis direction. Around the axis parallel to In In the second mounting part A coil part pivotally attached to the coil part and a first arm part and a second arm part extending from the coil part are provided. The first arm portion is connected to the drive plate, and the second arm portion is connected to the barrier blade. The first arm part and the second arm part are opened at a predetermined angle. When a rotational force is applied to the first arm portion connected to the drive plate, the coil portion rotates, the force is transmitted to the second arm portion, and transmitted to the barrier blades connected to the second arm portion. Is done. At this time, since the load on each barrier blade is small, the torsion angle between both arm portions hardly changes. That is, a region where the twist angle of the torsion coil spring hardly changes is provided between the open state and the closed state of the barrier blade. Therefore, the torsion coil spring functions as a driving force transmission means that can transmit the rotational driving force of the driving plate stably and reliably. The driving force transmission means constituted by the torsion coil spring is a simple mechanism and can be arranged in a narrow space. The first arm portion and the second arm portion of the torsion coil spring extend radially around the coil portion, and are output from the direction of the rotation input applied to the first arm portion and the second arm portion. Since the direction of the rotational output is the tangential direction with respect to the coil rotation axis, the mechanical direction that works during input / output is ideal.
[0010]
Further, when the barrier blades come into contact with each other and are in a closed state, the second arm portion is fixed so as not to move. In this state, when further force is applied to the first arm portion, the coil portion is prevented from rotating and the first arm portion rotates. That is, the first arm portion is twisted with respect to the second arm portion, and the torsion angle between both arm portions changes. In response to the change in the twist angle, a spring force is generated from the coil portion, and this spring force is urged against the second arm portion. Therefore, the torsion coil spring functions as a biasing means.
[0011]
As described above, in the lens barrier unit using the torsion coil spring, the torsion coil spring functions as the driving force transmitting means and the urging means, so that the mechanical parts of the lens barrier unit are simplified. At the same time, since the torsion coil spring is pivotally mounted in the direction of the optical axis, the space extending in the radial direction perpendicular to the optical axis is saved. Therefore, the lens barrier unit can be opened greatly even if it is downsized.
[0012]
In addition, a base plate can be made into various structures. The base plate can be constituted by, for example, a base plate body and a press plate. That is, the base plate body, the barrier blades, the presser plate, and the drive plate are arranged in an overlapping manner, and the barrier blades are sandwiched and pivotally connected between the base plate main body and the presser plate. You can also. Also, a locking portion for pivotally pivoting the barrier blade and locking to the straight cylinder mounting boss is provided on the straight cylinder mounting boss of the base plate so that the function of the press plate is included in the base plate. Thus, a configuration in which the presser plate is omitted may be employed.
[0013]
Further, it is necessary to adjust the movement stroke of the barrier blades by various tolerances such as part shape tolerance or assembly tolerance or design changes. In the prior art using a tension or compression spring, it was necessary to change the position of the boss of each molded part, so it was necessary to change from the mold of the molded part. However, with a torsion coil spring, it is only necessary to change the length of the arm portion of the torsion coil spring, so that the stroke can be easily corrected.
[0014]
After the barrier blades come into contact with each other and are fully closed, when the drive plate is further rotated, spring force is applied to the barrier blades, that is, overcharged, thereby improving the adhesion between the barrier blades. . Therefore, the structure is extremely strong against dust and the like. Further, by optimizing the spring force of the coil portion, even if a foreign object or a finger is caught when the lens barrier unit moves from the open state to the closed state, they can be easily removed. That is, the torsion coil spring is also used as a safety mechanism.
[0015]
In the camera lens barrier unit, specifically, the first mounting portion and the second mounting portion are configured as bosses extending in the optical axis direction.
[0016]
In each 1st attachment part and 2nd attachment part, the 2nd attachment part is arrange | positioned near the 1st attachment part. The torsion coil spring pivotally attached to the second attachment portion is a space adjacent to the barrier blade in the operation direction of the barrier blade pivotally attached to the first attachment portion, and does not interfere with the opening / closing operation locus of the barrier blade. Placed in place. The torsion coil spring is a gap between the base plate and the drive plate and is disposed in the same plane as the barrier blades, that is, in a plane, and the lens barrier unit is in the thickness direction, that is, in the optical axis direction. The structure is not thick. Therefore, the lens barrier unit and the camera can be thinned.
[0017]
The barrier blade, the first mounting portion, and the second mounting portion 2 each And they cooperate to open and close the opening. When the drive plate is driven to rotate about the optical axis, each barrier blade rotates in cooperation with each first attachment portion as a rotation center to open and close the opening of the base plate. Therefore, the opening / closing mechanism of the base plate opening can be simplified.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a lens barrier unit according to an embodiment of the present invention will be described in detail with reference to FIGS.
[0019]
FIG. 1 shows a state in which the lens barrier unit 40 of the present invention is mounted on the front surface of the lens barrel 10. The lens barrel 10 has a rectilinear cylinder 30 to which the lens barrier unit 40 is mounted on the front surface thereof, and is rotatably fitted to the rectilinear cylinder 30 outside the rectilinear cylinder 30 and has a first engagement at the tip. A cam ring 20 provided with a piece 22 (see FIG. 2) and a lens group 12 built in a rectilinear cylinder 30 and imaged on a film surface of light 16 incident from a subject.
[0020]
The lens barrier unit 40 has a structure in which a base plate 50, a pair of barrier blades 40a, a presser plate 80, and a drive plate 90 are arranged in an overlapping manner from the subject side (hereinafter referred to as the front side). . The lens barrier unit 40 is screwed into a screw hole provided on the front surface of the rectilinear cylinder 30 with a fixing screw 99a.
[0021]
FIG. 2 is a view of the lens barrier unit 40 in the fully opened state as viewed from the lens side of the camera (hereinafter referred to as the rear side). In FIG. 2, the drive plate 90 is represented as a solid line. In the base plate 50, the outer blade 60, the inner blade 70, and the presser plate 80, portions hidden by the drive plate 90 are represented by dotted lines.
[0022]
The base plate 50 is substantially ring-shaped, and includes a substantially rectangular opening 18 having rounded corners. On the rear surface side of the ring-shaped portion, a pair of first mounting portions, i.e., straight cylinder mounting bosses 51, which are arranged with the optical axis as a point target, project. These straight-advanced cylinder mounting bosses 51 are cylindrical, and a boss hole 99a is formed therethrough. In addition, a pair of second mounting portions, that is, a torsion coil spring boss 52, which is disposed with the optical axis as a point target, protrudes from the ring-shaped portion on the rear surface side, adjacent to the straight cylinder mounting boss 51. . A torsion coil spring 100 described later is attached to the boss 52 for torsion coil spring. The ring-shaped portion is provided with four first locking portions.
[0023]
The pair of barrier blades 40 a for closing the opening 18 includes a first barrier blade 41 and a second barrier blade 42. The first barrier blade 41 and the second barrier blade 42 are arranged so that the optical axis 14 is a point-symmetrical center. The first barrier blade 41 and the second barrier blade 42 are each composed of an outer blade 60 and an inner blade 70. That is, the barrier blade 40 a is configured by a total of four blades, that is, two outer blades 60 and two inner blades 70. The two outer blades 60 have the same shape, and the two inner blades 70 also have the same shape. Each outer blade 60 is on the same plane and is disposed such that the optical axis 14 is the center of point symmetry. Similarly, the inner blades 70 are also on the same plane and are arranged so that the optical axis 14 is a point-symmetrical center. The outer blade 60 is arranged so as to be shifted in the front direction of the optical axis with respect to the inner blade 70. The outer blade 60 and the inner blade 70 are shaped and dimensioned so as to be stored in an overlapping manner in a ring-shaped portion around the opening 18 in the open state.
[0024]
The outer blade 60 is provided with a blade body 64 which is a substantially “<”-shaped flat plate, and is provided at the base end of the blade body 64 so as to be pivotally attached to the straight tube mounting boss 51, and the straight tube mounting boss 51 is centered. And a shaft portion 67 having a fitting hole for rotating. A notch engaging piece 62 protruding in the axial direction is formed on the rear surface side near the base end of the blade body 64 and on the optical axis side. An abutting action piece 69 protruding in the axial direction is formed on the rear side surface of the distal side of the blade body 64.
[0025]
Like the outer blade 60, the inner blade 70 is provided at the base end of the blade main body 74, which is a substantially “<”-shaped flat plate, and is pivotally attached to the straight cylinder mounting boss 51 to advance straight. A shaft portion 77 having a fitting hole for rotating around the tube mounting boss 51 is provided, and a spring engaging portion 79 extending from the shaft portion 77 is provided on the opposite side of the blade body 74. .
[0026]
Near the base end of the blade body 74 of the inner blade 70 and on the side surface on the optical axis side, the notch 72 is formed at a position where it engages with the notch engaging piece 62 of the outer blade 60. In the process of closing the inner blade 70, the notch 72 engages with the notch engaging piece 62 of the outer blade 60, and the outer blade 60 is pulled out in the optical axis direction.
[0027]
A contact side 73 is formed on the side of the blade body 74 on the centrifugal side. When the inner blade 70 returns to the open state, the contact side 73 contacts the contact action piece 69 and is pushed in the centrifugal direction.
[0028]
On the side surface of the blade body 74 on the optical axis side, a contact closing side 75 whose edge is processed into a stepped shape is formed. In the closed state of the lens barrier unit 40, the contact closed side 75 of one inner blade 70 contacts the contact closed side 75 of the other inner blade 70, and the lens barrier unit 40 is closed, so that the external Intrusion of dust from is prevented.
[0029]
The spring engaging portion 79 includes a slit-shaped guide hole 79 extending in a substantially longitudinal direction. The guide hole 79 engages with a second protruding piece 103b of a torsion coil spring 100 described later.
[0030]
The presser plate 80 is a substantially ring-shaped thin plate and includes a substantially rectangular opening 18 having rounded corners. The opening 18 has the same shape as the opening 18 of the base plate 50, and is configured such that the two openings overlap. A pair of boss through holes 86 for receiving the pair of straight cylinder mounting bosses 51 of the base plate 50 are formed in the ring-shaped portion. The straight cylinder mounting boss 51 is inserted into the boss through hole 86 so as to protrude slightly toward the drive plate 90.
[0031]
Further, two torsion coil spring boss holes 88 arranged with the optical axis 14 as a point symmetry center are formed in the ring-shaped portion of the presser plate 80 adjacent to the boss through hole 86. The torsion coil spring boss 52 is inserted into the torsion coil spring boss hole 88, but is dimensioned so that the tip of the torsion coil spring boss 52 does not protrude from the surface of the presser plate 80.
[0032]
At each position adjacent to the torsion coil spring boss hole 88, an arcuate slit protruding piece floating hole 82 centering on the torsion coil spring boss hole 88 is formed. The first protruding piece 103a of the torsion coil spring 100 is mounted so as to slightly protrude toward the rear surface side through the protruding piece floating hole 82. In addition, the slot width of the protruding piece floating hole 82 is configured to be wider than the width of the first protruding piece 103a of the torsion coil spring 100 so that the length of the arm portions 102a and 102b of the torsion coil spring 100 can be changed. Yes. Further, the circumferential length of the protruding piece floating hole 82 is such that the first protruding piece 103a of the torsion coil spring 100 moves at a minimum when the lens barrier unit 40 is opened and closed so that the spring force is overcharged. Designed to be longer than necessary to do. On the side surface of the presser plate 80, a second locking portion that is fitted to the first locking portion of the base plate 50 is provided. The first locking portion and the second locking portion are fitted to each other to form the locking portion 110. At this time, the interval between the base plate 50 and the presser plate 80 is dimensioned so that the outer blade 60 and the inner blade 70 can freely move between the base plate 50 and the presser plate 80. Further, the spring locking piece 120 protrudes on the surface of the presser plate 80.
[0033]
It is also possible to adopt a configuration in which the presser plate 80 is omitted. That is, in the rectilinear cylinder mounting boss 51 of the base plate 50, the barrier blade 40 a is pivotally mounted so as to be engaged with the rectilinear cylinder mounting boss 51. The function can be included in the base plate 50.
[0034]
The drive plate 90 has a substantially ring shape and includes a pair of boss guide holes 93 and a spring locking guide hole 96. Each boss guide hole 93 extends in an arc shape centering on the optical axis 14, and the straight cylinder mounting boss 51 is inserted into the boss guide hole 93. Depending on the length of the boss guide hole 93 in the circumferential direction, the amount of rotation of the drive plate 90 relative to the straight cylinder mounting boss 51 is restricted.
[0035]
The slits 92 extending in the radial direction are provided in the vicinity of the boss guide hole 93 and at positions corresponding to the first protruding pieces 103 a of the torsion coil spring 100. The first protruding piece 103 a protruding from the presser plate 80 is engaged with the slit 92. The spring locking guide hole 96 extends in an arc shape around the optical axis 14 and has a spring hooking piece 95 at one end in the circumferential direction. In the spring locking guide hole 96, a spring 121 having one end locked by the spring hooking piece 95 and the other end locked by the spring locking piece 120 is held, and a spring force in the compression direction is applied. It is energized. A second engagement piece 91 extending in an arc shape around the optical axis 14 is provided on the outer peripheral edge of the ring-shaped portion, and the second engagement piece 91 is a first engagement of the cam ring 20. The drive plate 90 is rotated by being pushed by the piece 22.
[0036]
The torsion coil spring 100 is made of an elastic body such as metal or resin, and extends in the lateral direction from the coil portion 101 that generates a spring force, one end on the drive plate side of the coil portion 101 and the other end on the base plate side. The first arm portion 102a and the second arm portion 102b, and a first projecting piece 103a and a second projecting piece 103b extending from the arm portions 102a and 102b in the axial direction and the rear surface direction, respectively. At least the coil portion 101 of the torsion coil spring 100 is smaller than the thickness of the barrier blade 40 a, and the torsion coil spring 100 is contained in the gap between the base plate 50 and the presser plate 80.
[0037]
FIG. 7 shows the configuration around the torsion coil spring 100 so that the configuration around the torsion coil spring 100 can be clearly understood. FIG. 7 is a cross-sectional view of the lens barrier unit 40 of FIG. 2 as seen from the direction of the arrow along the line 7-7. In FIG. 7, details of the barrier blade 40a are omitted. The coil portion 101 is pivotally attached to the torsion coil spring boss 52 of the base plate 50. That is, the coil portion 101 is a space formed between the base plate 50 and the presser plate 80 so that the barrier blade 40a can rotate and extends in the radial direction with respect to the optical axis 14, and the barrier blade 40a. Is pivotally attached to a boss 52 for a torsion coil spring provided at a place where it does not interfere with the opening / closing movement locus of the torsion coil spring. The first arm portion 102a is twisted at a predetermined angle with respect to the second arm portion 102b. The first projecting piece 103 a is engaged with the slit 92 of the drive plate 90 through the projecting piece idle hole 82 of the presser plate 80. At the same time, the second protruding piece 103 b is engaged with the spring engaging portion 79 of the inner blade 70. Therefore, when the drive plate 90 is rotationally driven, a rotational force in a certain direction is applied to the first arm portion 102a. This rotational driving force rotates the coil unit 101 and is transmitted to the second arm unit 102b, thereby rotating the second arm unit 102b in the same direction. At this time, the twist angle between the first arm portion 102a and the second arm portion 102b hardly changes.
[0038]
Since the straight cylinder mounting boss 51 to which the barrier blade 40a is pivotally attached and the torsion coil spring boss 52 to which the torsion coil spring 100 is pivotally attached are disposed adjacent to each other, the torsion coil spring 100 is connected to the barrier blade 40a. Thus, the operating area of the torsion coil spring 100 is reduced, and space saving can be achieved.
[0039]
Further, by changing the lengths of the first arm portion 102a and the second arm portion 102b, various tolerances can be absorbed and adjustment can be performed to perform a predetermined operation. Also, moment adjustment when rotating the torsion coil spring 100 can be easily performed.
[0040]
Next, the opening / closing operation | movement of the lens barrier unit 40 comprised in this way is demonstrated according to FIGS.
[0041]
When the camera is not used, the lens barrel 10 is in the retracted position. However, in order to use the camera, when the main switch (not shown) provided in the camera body is turned on, the lens barrel 10 protrudes, and FIG. As shown, the lens barrier unit 40 is fully opened. That is, as shown in FIG. 2, in the fully opened lens barrier unit 40, all the outer blades 60 and the inner blades 70 are completely housed in the ring-shaped portion around the opening 18. Since the spring urging force in the clockwise direction acts on the drive plate by the spring 121 provided between the presser plate 80 and the drive plate 90 locked to the base plate 50, the outer blade 60 and the inner blade 70 are fully opened. State is maintained. Further, the first engagement piece 22 of the cam ring 20 is not in contact with the second engagement piece 91 of the drive plate 90.
[0042]
In order to shift from this state to a retracted state in which the camera is not used, the cam ring 20 is rotated counterclockwise. When the cam ring 20 rotates counterclockwise, the first engagement piece 22 of the cam ring 20 comes into contact with the second engagement piece 91 of the drive plate 90, and the closed state start position shown in FIG.
[0043]
When the cam ring 20 is further rotated counterclockwise, the first engagement piece 22 of the cam ring 20 pushes the second engagement piece 91 of the drive plate 90 as shown in FIG. The drive plate 90 rotates counterclockwise about the optical axis 14 against the urging force. Along with this rotation, the torsion coil spring is applied to the first arm portion 102a extending laterally from the first protruding piece 103a of the pair of torsion coil springs 100 engaged with the slits 92 of the drive plate 90. A rotational driving force is applied to rotate clockwise about the boss 52 for use. This force is transmitted to the second arm portion 102b while rotating the coil portion 101. At this time, the twist angle between the first arm portion 102a and the second arm portion 102b hardly changes. Since the second protruding piece 103b extending in the axial direction from the second arm portion 102b is engaged with the protruding piece guide hole 79 of the spring engaging portion 78 of the inner blade 70, the spring engaging portion 78 is pivoted. It rotates counterclockwise around the portion 77, that is, the straight cylinder mounting boss 51. At the same time, the blade body 74 of each inner blade 70 rotates counterclockwise about the shaft portion 77, that is, the straight cylinder mounting boss 51. Accordingly, the inner blades 70 cooperate to close the opening 18. Thus, the torsion coil spring 100 is composed of the drive plate. 90's It functions as a driving force transmission means for transmitting the rotational driving force to the inner blade 70 stably and reliably. Then, the notch 72 provided in the inner blade 70 is engaged with the notch engaging piece 62 of the outer blade 60, and the notch engaging piece 62 is pushed by the notch 72. As a result, the outer blade 60 also rotates counterclockwise around the shaft portion 67, that is, the straight cylinder mounting boss 51. Accordingly, each outer blade 60 and inner blade 70 cooperate to close the opening 18.
[0044]
When the cam ring 20 further rotates counterclockwise, the drive plate 90, the torsion coil spring 100, and the barrier blade 40a perform the same operations as described in FIG. Then, as shown in FIG. 5, when the contact closing sides 75 of the inner blades 70 come into contact with each other, the rotation of the inner blades 70 stops and the lens barrier unit 40 is fully closed.
[0045]
The cam ring 20 can further rotate from the fully closed state. When the cam ring 20 further rotates counterclockwise, the drive plate 90 rotates counterclockwise. The first arm portion 102a engaged with the drive plate 90 further rotates clockwise around the torsion coil spring boss 52. However, since the inner blades 70 are in contact with each other and locked, the second arm portion 102a is locked. The arm part 102b cannot rotate. As a result, only the first arm portion 102a rotates, and the twist angle between the first arm portion 102a and the second arm portion 102b becomes small. As a result, the coil portion 101 functions as an elastic body, and the torsion coil spring 100 is overcharged. Therefore, the closed state in which the inner blades 70 are strongly pressed against each other by the biasing force of the torsion coil spring 100 is maintained. Therefore, it becomes a very strong structure with respect to intrusion of dust or the like. Then, by optimizing the spring force of the coil portion 101, even if a foreign object or a finger is caught when the lens barrier unit 40 moves from the open state to the closed state, they can be easily removed. That is, the torsion coil spring 100 is also used as a safety mechanism. At this time, the lens barrel 10 is in the retracted position.
[0046]
When projecting the lens barrel 10 from the retracted position, the cam ring 20 is rotated in the opposite direction, that is, clockwise. The lens barrier unit 40 performs an operation substantially opposite to the operation in the retracted state described above, but the operations of the outer blades 60 and the inner blades 70 are different. That is, when the inner blade 70 rotates clockwise around the shaft portion 77, that is, the straight cylinder mounting boss 51, first, the engagement between the notch 72 of the inner blade 70 and the notch engaging piece 62 of the outer blade 60 is released. Is done. When the inner blade 70 further rotates clockwise, the contact side 73 of the inner blade 70 contacts the contact action piece 69 of the outer blade 60. When the inner blade 70 further rotates, the outer blade 60 rotates in the clockwise direction around the shaft portion 67, that is, the straight cylinder mounting boss 51 in cooperation with the inner blade 70. And the outer blade | wing 60 and the inner blade | wing 70 will be completely accommodated in the ring-shaped part around an opening part, and will be in the fully open state which the opening part 18 opened fully. When the cam ring 20 is further rotated in the clockwise direction, the engagement between the first engagement piece 22 of the cam ring 20 and the second engagement piece 91 of the drive plate 90 is released. By energizing the spring force 121, the lens barrier unit 40 in an always open state is held.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which a lens barrier unit according to an embodiment of the present invention is mounted on a lens barrel.
FIG. 2 is a diagram illustrating a fully opened state of the lens barrier unit.
FIG. 3 is a diagram illustrating a closing operation start state of the lens barrier unit.
FIG. 4 is a diagram showing a state during the closing operation of the lens barrier unit.
FIG. 5 is a diagram illustrating a fully closed state of the lens barrier unit.
FIG. 6 is a diagram illustrating a fully closed overcharge state of the lens barrier unit.
7 is a cross-sectional view of the lens barrier unit shown in FIG. 2 as viewed from the direction of the arrow along the line 7-7. FIG.
[Explanation of symbols]
10 Lens barrel
12 Lens groups
14 Optical axis
18 opening
20 cam ring
22 First engagement piece
30 Straight cylinder
40 Lens barrier unit
40a barrier blade
41 First barrier blade
42 Second barrier blade
50 base plate
51 Straight cylinder mounting boss (first mounting part)
52 Boss for torsion coil spring (second mounting part)
60 outer feather
62 Notch engagement piece
64 Feather body
67 Shaft
69 Contacting piece
70 Inner feather
72 Notches
73 Contact side
74 Blade body
75 Abutting closure
77 Shaft
78 Spring engagement part
79 Guide hole for protruding piece
80 Presser plate
82 Loose hole for protruding piece
86 Boss through hole
88 Boss hole for torsion coil spring
90 Drive plate
91 Second engagement piece
92 slits
93 Boss guide hole
94 Ring-shaped part
95 Spring hook
96 Spring locking guide hole
99a Boss hole
99b fixing screw
100 torsion coil spring
101 Coil part
102a 1st arm part
102b Second arm part
103a First protruding piece
103b Second protruding piece
110 Locking part
120 Spring locking piece
121 spring

Claims (5)

A ring-shaped base plate attached to the front end of the lens barrel and having an opening;
A drive plate that has an opening at least in a portion facing the opening and is rotatable with respect to the base plate;
Between the base plate and the drive plate, in order to open and close the opening of the base plate, it is constituted by a barrier blade pivotally attached to a first mounting portion disposed on the base plate,
A lens barrier unit for a camera in which a barrier blade opens and closes an opening of a base plate by rotating a drive plate around an optical axis,
A second mounting portion separate from the first mounting portion is formed at a predetermined position of the base plate, and the coil portion of the torsion coil spring pivots around the axis parallel to the optical axis direction on the second mounting portion. is deposited, while the first arm portion of該捩Ri coil spring is coupled to the drive plate, the second arm portion thereof by Rukoto connected to the barrier blades, the rotational driving force of the driving plate via a respective torsion coil springs Rutotomoni be transmitted to each of barrier blades, a camera lens barrier unit, characterized in that provided between the region where the torsion angle hardly changes of the torsion coil spring is an open state and a closed state of the barrier blades.   The camera lens barrier unit according to claim 1, wherein the first attachment portion and the second attachment portion are bosses extending in the optical axis direction.   The camera lens barrier unit according to claim 1, wherein the first mounting portion and the second mounting portion are positioned in the vicinity of each other.   The camera lens barrier unit according to claim 1, wherein the torsion coil spring has a spring force as a safety mechanism. 5. The camera lens according to claim 1, wherein there are two each of the barrier blade, the first mounting portion, and the second mounting portion, and they cooperate to open and close the opening. Barrier unit.

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