JP2606173Y2 - Camera shutter blade opening and closing mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter blade opening / closing mechanism used in a camera shutter device, and more particularly to an improvement in a camera shutter blade opening / closing mechanism suitable for use in a compact camera.

[0002]

2. Description of the Related Art A shutter blade opening / closing mechanism in a conventional shutter device for a camera is disclosed, for example, in Japanese Utility Model Application Laid-Open No. 3-12533.
It is configured as in JP-A-7.

[0003] Fig. 10 shows a conventional Japanese Utility Model Laid-Open No. 3-125.
In order to easily compare the camera shutter blade opening / closing mechanism disclosed in Japanese Patent Publication No. 337 with the camera shutter blade opening / closing mechanism according to the present invention, the direction of forward movement of the driving member 101 is changed in the counterclockwise direction. FIG.
It should be noted that the reference numerals used in FIG.
100.

The publication discloses a driving member 101 having a cam surface 101a and a blade opening / closing lever 102 having a projection 102a abutting on the cam surface 101a. Face 101
a and the protrusion 102a cooperate to operate the blade opening / closing lever 1
02 reciprocated, shutter blades (no sign)
In a camera shutter that opens and closes, a claw lever 10 having a claw portion 109a on a driving member 101 is provided.
When the drive member 101 moves forward (when the shutter blade is opened), the protrusion 102a is brought into sliding contact with the claw portion 109a of the claw lever 109, and then the blade opening / closing lever 102 is moved. There is disclosed a technique of a shutter blade opening / closing mechanism configured to be actuated and to retreat the claw portion 109a from the cam surface 101a when returning.

Incidentally, reference numeral 101c in FIG.
09 is a stopper for determining the initial position, and 11
Numeral 0 denotes a return spring for constantly urging the claw lever 109 clockwise.

In the disclosed technique, the driving member 10
After the projection 102a of the blade opening / closing lever 102 first comes into sliding contact with the claw 109a of the claw lever 109 at the time of the forward movement of 1,
Since the outer portion 109b following this is formed so as to occupy a position slightly retracted from the movement locus of the projection 102a of the blade opening / closing lever 102, the blade opening / closing lever 102
Is characterized in that it can quickly move forward without resistance by the biasing force of a spring (reference numeral 3 in the publication).

[0007]

However, in this shutter blade opening / closing mechanism, the drive member 10 is pivotally mounted on the drive member 101 because the claw lever 109 is pivotally mounted on the drive member 101.
1 increases the weight and the center of gravity of the entire driving member 101 is deviated.

Therefore, (a) the inertia increases when the drive member 101 rotates, and the increase in the inertia causes a response delay of the drive member 101 at the time of start-up or reversal. There is a possibility that accuracy may be reduced. (B) When a stepping motor is used as a drive source (actuator) for the drive member 101, the risk of step-out increases.

(C) Driving member 10 reciprocating at high speed
(1) In a structure in which the claw lever 109 is pivotally connected by a connecting means such as "caulking", there is a variety of problems that there is a risk that the "caulking" portion may be loosened when used for a long time. Will be generated.

By the way, in such a shutter blade opening / closing mechanism, in the process of opening the shutter blade,
When a structure in which the claw portion 109a of the claw lever 109 moves (clockwise rotation) in accordance with the movement (counterclockwise rotation) of the cam surface 101a of the driving member 101, the claw lever 109 is used. When the locking of the blade opening / closing lever 102 is released by the
02a must not be brought into contact with the pawl lever 109 and the cam surface 101a.

However, with this configuration, it is necessary to increase the overhang amount of the claw portion 109a of the claw lever 109. As a result, in the course of the closing operation of the shutter blade, when the driving member 101 moves from the open position of the shutter blade to the aperture closing position of the shutter blade, the blade opening / closing lever 102 is moved at an intermediate position (intermediate aperture position) of the closing operation. The projection 102a is the claw lever 10
9, the urging force of the return spring 110 of the claw lever 109 is applied as a sliding contact resistance to the rotational movement of the driving member 101 thereafter.

Therefore, when such a phenomenon occurs, (d) it is necessary to increase the rotational force in the closing direction of the driving member 101 by the sliding contact resistance. (E) Exposure accuracy, especially in the small stop area This causes a problem that causes a variation of the data.

The present invention has been made in view of such circumstances, and has a problem in the conventional camera shutter blade opening / closing mechanism described in the above items (a) to (e) in the camera shutter blade opening / closing mechanism. It is an object of the present invention to provide a camera shutter blade opening / closing mechanism having a configuration capable of eliminating points or defects.

[0014]

According to the present invention, a shutter blade reciprocatingly rotating between an aperture closing position and an open aperture opening position, and a bell crank shape are provided.
One arm has a locked part and the other arm has a blade
A drive unit for an opening / closing ring is provided, and the shutter blade is ultimately opened and closed by reciprocating rotation between an initial position corresponding to the aperture closing position of the shutter blade and a maximum rotation position corresponding to the open aperture opening. A blade opening / closing lever; first biasing means for biasing the blade opening / closing lever to rotate from an initial position toward the maximum rotation position;
The object of the blade opening lever against the biasing force of the biasing means
Have the locking end to releasably lock the locking portion to its initial position
A locking lever, a second biasing means for urging the locking lever so as to always toward its initial position, the cam slopes該Ka
Cam projection with a continuous cam top surface
And a drive member that is driven to rotate in a reciprocating direction by the electric motor, met camera shutter blade opening and closing mechanism and a base plate for holding each of these members and means, and the locking lever and the blade opening lever together detachably provided on the base plate, the said engaged portion of the front <br/> SL blade operating lever in a state in which the blade opening lever is rotated until the cam top portion formed on said drive member Engagement of locking lever
Configure so that there is a gap between it and the toe .
The cam projection rotates slightly from the cam top to the cam slope
And reaches the object to be locked part is configured so that the by <br/> Rigakaritome with the locking portion of the locking lever, in response to a shutter release
The locking of the blade opening / closing lever by the locking lever is released by the function of a locking release action portion formed on the driving member that rotates in the forward direction, and the urging force of the first urging means causes the blade to be unlocked. Rotating the blade opening / closing lever from its initial position toward the maximum rotation position to expose the driving member
After rotating by the angle determined by the body brightness, immediately return
It is characterized in that it is configured to be able to reversely rotate toward .

[0015]

The shutter blade mechanism for a camera configured as described above pivotally locks the locking lever to the base plate to reduce the rotational inertia of the driving member, thereby reducing the operation delay of the mechanical member caused by the rotational inertia. In a practically acceptable range, thereby realizing high-precision exposure control and high-speed shutter time.

Further, when the locking lever and the blade opening / closing lever are pivotally attached to the main plate, and when the locking end of the locking lever locks the locked portion of the blade opening / closing lever, the locking lever is engaged. The locking lever is rotated by the counterclockwise rotation of the blade opening / closing lever so that the toe protrudes slightly into the rotation locus of the locked portion of the blade opening / closing lever, and during the rotation of the driving member in the backward direction. The rotation center of the locking lever is set so that when the is rotated, the locking end of the locking lever can move in a direction deviating from the rotation locus of the locked portion of the blade opening / closing lever.

For this reason, in the closing process of the shutter blade, until the blade opening / closing lever reaches the pinhole position from the position of the open aperture opening of the shutter blade, the locked portion of the blade opening / closing lever is moved to the tip of the lower arm of the locking lever. It is possible to configure so as not to contact the part.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the structure will be described in detail based on one embodiment of the present invention. In this description, the term "open area" means that an appropriate EV value is obtained depending on the open time on the low luminance side. The "program area" refers to an area in which a program-type exposure control, that is, a so-called triangular wave aperture is performed.

FIG. 1 is a plan view showing a main part of an embodiment of a shutter blade opening / closing mechanism for a camera according to the present invention.
2 to 9 are operation state diagrams showing the operation state of the camera shutter blade opening / closing mechanism of FIG. 1 in time series.

In FIG. 1, O denotes an optical axis of a photographic lens provided in a lens barrel (both not shown) fixed to a compact camera, for example, and 1 denotes a ring-shaped base plate fixed to the lens barrel. .

Reference numeral 2 denotes a forward direction (counterclockwise) and a backward direction (clockwise) around the optical axis O on the front surface of the main plate 1.
A ring-shaped driving member rotatably provided at the initial position is set to a diaphragm closing position (a position shown in FIG. 1) where a shutter blade 10 described later is completely closed.
Further, it is configured to have a cam projection 21 on a part of the outer peripheral portion.

The cam projection 21 has a top portion formed as a cam top portion 21b, and a bottom portion thereof forms a maximum rotation amount or a rotation angle of a later-described blade opening / closing lever 3 (an open aperture opening of the shutter blade 10). (A rotation amount or a rotation angle of the blade opening / closing lever 3 necessary for the above) is formed as a cam bottom portion 21c.

The cam top 21 of the cam projection 21
The side facing clockwise between b and the cam bottom 21c is formed as a cam slope 21a, and the cam shape is such that both the open area and the program area are used when the drive member 2 is inverted (clockwise). Locked part 3 of blade opening / closing lever 3
a depends on the cam slope 21a of the drive member 2 and is formed as a continuous and gentle slope so as to be pushed up smoothly.

(A) In the case where the present invention is applied to the open area, the cam slope 21a moves from the position corresponding to the opening position of the shutter blade 10 to the position corresponding to the aperture closing position of the shutter blade 10. In the process of rotating in the backward direction, the cam slope 21a for returning the blade opening / closing lever 3 to its initial position.
Will be configured to act as

(B) In the case where the present invention is applied to the program area, the cam slope 21a rotates in the forward direction from the initial position of the driving member 2 toward the position where the open aperture opening of the shutter blade 10 is obtained. In the process, the post-collision drive member 2 collides with the locked portion 3a of the blade opening / closing lever 3 to act as a cam slope 21a for setting an intermediate aperture opening of the shutter blade 10 determined by the subject brightness at that time. During the rotation of the shutter blade 10 in the backward direction from the position corresponding to the open position of the shutter blade 10 toward the position corresponding to the aperture closing position, it acts as a cam slope for returning the blade opening / closing lever 3 to its initial position. Will be configured.

This will be described in detail in the section of the shutter blade 10 which will be described later and the "operation or action" of the illustrated embodiment. The driving member 2 is configured to have a partial gear portion 22 in an outer peripheral region located on a side substantially opposite to the cam projection 21 across the optical axis O. Part 22
Is configured to be able to mesh with a small gear 18b of the intermediate gear 18 described later.

Further, the driving member 2 is also configured to have a pushing projection 23 on a part of the rear end surface.
The push projection 23 constitutes the “lock release action portion” described in the claims of the utility model registration, and its configuration will be described in relation to the lock lever 12 described later. To

Reference numeral 3 denotes a blade opening / closing lever pivotally supported on the main plate 1 by a pivot 4 so as to be reciprocally rotatable. A locked portion 3a is provided at the tip of one of the two arms arranged in a bell crank shape. And a U-shaped groove 3b at the tip of the other arm.

Reference numeral 5 denotes a first torsion spring which is a first biasing means for constantly biasing the blade opening / closing lever 3 in a clockwise direction. One end of the first torsion spring is hung on a pin 6 fixed on the main plate 1. ,
The other end is hooked on a pin provided on one arm of the blade opening / closing lever 3.

Reference numeral 7 denotes a locking lever 12 under the driving member 2.
The center arm tip portion 123 is positioned so as to have a clearance capable of entering and exiting between both members, and is provided so as to be rotatable in the forward direction (counterclockwise) and the backward direction (clockwise) about the optical axis O. In the opening / closing ring, an interlocking pin 8 that engages with the U-shaped groove 3b of the blade opening / closing lever 3 is implanted in a large protruding portion formed at one portion of the outer peripheral portion. An aperture pin 9 that fits into an oval control cam groove 10a of a shutter blade 10 to be described later is implanted in each of the small projections (only one is shown in the figure) formed at the divided locations.

The blade opening / closing ring 7 is configured to be always rotated counterclockwise by the urging force of the first torsion spring 5 hung on the blade opening / closing lever 3, but a dedicated spring means ( It is also possible to provide a device (not shown) so as to be rotated by the biasing force of the spring means.

Reference numeral 10 denotes a shutter blade configured as, for example, three shutter blades (only one shutter blade is shown in the figure), and one end of each of the shutter blades 11 is provided on the base plate 1.
And is rotatably supported by the shutter blades 1.
0 is a control cam groove 10 at a position near each pivot 11.
a.

In this case, the three shutter blades 10 are configured so as to be able to open to the maximum aperture position, ie, the maximum aperture position, by rotating clockwise from the aperture closed position about the respective pivots 11. Has been
The open positions of the three shutter blades 10 will be described later in detail in “Case where the present invention is applied to open area” and “Case where the present invention is applied to program area”.

In the following description, regardless of whether the present invention is applied to an open area or a program area, the aperture formed by the opening position of the shutter blade 10 determined in this manner is set to a predetermined value. It is referred to as an aperture.

Reference numeral 12 denotes a locking lever pivotally connected to a position near the blade opening / closing lever 3 on the main plate 1 by a pivot 13 so as to be reciprocally rotatable. The locking lever 12 has three arm tips 121, 122 and 123. I have.

In this case, the locking lever 12 is configured to be constantly urged by the urging force of the second torsion spring 15 in a direction (counterclockwise) in which it comes into contact with the stopper 14, and the upper part is located at the upper part of the drawing. The position when the arm tip portion 121 comes into contact with the stopper 14 fixed on the main plate 1 by the urging force of the second torsion spring 15 is configured as its own initial position.

When the locking lever 12 is located at its initial position, the lower arm tip 122 located below the figure rotates the locked portion 3a of the blade opening / closing lever 3 clockwise. The lower arm tip 122 and the locked portion 3a of the blade opening / closing lever 3 are projected so as to protrude into the movement locus.
And a relative position of the blade opening / closing lever 3 with respect to the locked portion 3a is set in advance so that a gap Δg exists between the lever 3 and the locked portion 3a.

When the blade opening / closing lever 3 rotates clockwise around the pivot 4 as the driving member 2 rotates in the forward direction, as shown in FIG.
It is also configured so that the locked portion 3a of the blade opening / closing lever 3 can be locked by the tip end surface of the blade 2.

The relative position of the center arm tip 123 with respect to the pushing projection 23 of the driving member 2 is set in advance so as to protrude into the rotational movement locus of the pushing projection 23 of the driving member 2.

In this case, the amount of projection of the pushing projection 23 of the center arm tip 123 into the rotational movement locus and the driving member 2
The relative relationship between the maximum rotation amount (the maximum movement amount of the pushing projection 23) is

When the driving member 2 is moved from the initial position to the shutter blade 1
Position to achieve 0 aperture open state (position of maximum rotation amount)
In the process of rotating in the counterclockwise direction as shown in FIG. 4, as shown in FIG.
In contact with a, the center arm tip 123 is pushed clockwise against the urging force of the second torsion spring 15 to rotate the locking lever 12 clockwise around the pivot 13.

In this case, slightly before the driving member 2 reaches the position of the maximum rotation amount, the pushing projection 23 is moved to the locking lever 12.
Of the central arm tip 123 starts to be pushed counterclockwise, and the lower arm tip 122 of the locking lever 12 moves the locked portion 3a of the blade opening / closing lever 3 at the position of the maximum rotation amount. It is set to be a position to release fully.

When the driving member 2 rotates clockwise from the position of the maximum rotation amount toward the initial position, the tip 123 of the central arm of the locking lever 12 is rotated by the second torsion spring 1.
The biasing force of No. 5 is configured in advance so as to follow the movement of the pushing projection 23 in the clockwise direction and to set the relative relationship such that the locking lever 12 can return to the initial position.

Reference numeral 16 denotes, for example, a stepping motor for driving the driving member 2, which is provided at an appropriate position on the main plate 1. The stepping motor 16 is provided so as to be rotatable in the forward and reverse directions. The amount of rotation or rotation angle in the forward direction (counterclockwise) from the initial position (phase) and the initial position from the position after the forward rotation. Reverse to position (clockwise)
The rotation amount or rotation angle is controlled by an appropriate program type exposure control means (not shown) in accordance with the subject brightness at each time.

Reference numeral 17 denotes an output gear fixed to the output shaft of the stepping motor 16, and reference numeral 18 denotes an intermediate gear for transmitting the rotating operation of the output gear 17 to the gear portion 22 of the driving member 2. For example, a large gear 18a Meshes with the output gear 17,
The small gear 18b is configured as a two-speed reduction gear that meshes with the gear portion 22 of the drive member 2.

The operation or action of the shutter blade opening / closing mechanism for a camera according to the illustrated embodiment configured as described above will be described below for an open area and a program area to which the present invention is applied. [Case where the present invention is applied to the open area] When the shutter blade opening / closing mechanism is in the initial state, the movable members 2 to 18 except for the pivots 4 and 11 and the stepping motor 16 are in the initial state shown in FIGS. And the stepping motor 16 is also in the initial phase.

At this time, the upper arm tip 121 of the locking lever 12 is located at the initial position in contact with the stopper 14, and the lower arm tip 122 and the locked part 3 a of the blade opening / closing lever 3 are located between the lower arm tip 122 and the locked part 3 a of the blade opening / closing lever 3. The gap Δg as described above occurs (see FIG. 2).

When the shutter is released in this state, the stepping motor 16 starts to rotate from the initial position in the forward direction (counterclockwise), and the rotational movement is changed from the output gear 17 to the intermediate gear 18. Large gear 18a →
Since the transmission is transmitted to the partial gear portion 22 of the driving member 2 via the small gear 18b, the driving member 2 rotates in the forward direction (counterclockwise) from its initial position.

At this time, since the cam projection 21 formed on the drive member 2 also moves in the same direction as a unit, the blade opening / closing lever 3 which has been engaged with the cam top 21b of the cam projection 21 is locked. The portion 3a is displaced from its engagement position and slightly moved by the urging force of the first torsion spring 5,
As shown in FIG. 3, the lower lever 12 engages with the distal end surface of the lower arm distal end portion 122 of the locking lever 12.

The first torsion spring 5 is held at this engaging position by the urging force of the first torsion spring 5. That is, the blade opening / closing lever 3
Of the lower arm 1 of the locking lever 12
22 is locked.

However, since the driving member 2 continues to rotate in the forward direction as it is, the pushing projection 23 of the driving member 2 is attached to the counterclockwise side surface 123 a of the tip 123 of the central arm of the locking lever 12. In engagement, the center arm tip 123 of the locking lever 12 is pushed clockwise around the pivot 13 against the biasing force of the second torsion spring 15.

When the tip 123 of the central arm of the locking lever 12 is pushed clockwise by the pushing projection 23, the tip 122 of the lower arm of the locking lever 12 also rotates clockwise, and the tip of the lower arm 122 rotates clockwise. The surface moves to a position outside the rotational movement trajectory of the locked portion 3 a of the blade opening / closing lever 3, so that the locking state of the lower arm tip 122 of the locking lever 12 with respect to the blade opening / closing lever 3 is at this time. As a result, the blade opening / closing lever 3 can be rapidly rotated clockwise by the urging force of the first torsion spring 5.

In this case, the rotation amount or rotation angle of the stepping motor 16 in the forward direction is set to a rotation amount or rotation angle enough to rotate the blade opening / closing lever 3 to a position where the shutter blade 10 obtains the open aperture opening. Therefore, the driving member 2 rotates in the forward direction to a position where the blade opening / closing lever 3 can obtain the open aperture opening, and stops at that position. Therefore, the blade opening / closing lever 3 rapidly rotates clockwise to a position where an open aperture opening is obtained (see FIG. 4).

On the other hand, when the blade opening / closing lever 3 rotates clockwise, the blade connected to the blade opening / closing lever 3 by an interlocking mechanism of the interlocking pin 8 implanted therein and the U-shaped groove 3 b of the blade opening / closing lever 3. The opening / closing ring 7 is rotated counterclockwise by the urging force of the first torsion spring 5 or the urging force of a dedicated spring means (not shown), and the three shutter blades 10 are rotated through the aperture pin 9 and the control cam groove 10a. Is rotated about each pivot 11 to a position where an open aperture is obtained. That is, as shown in FIG. 6, an open aperture opening of the shutter blade 10 is formed at this time.

The stepping motor 16 is configured such that the shutter blade 10 rotates (reversed) in the opposite direction after forming the open aperture opening. When the shutter is formed, the inversion is started immediately. In the case of a long shutter time, the inversion is started after a lapse of a predetermined time from the time when the open aperture opening is formed.

Accordingly, the driving member 2 which has been stopped at the position corresponding to the position where the open aperture opening can be obtained, moves toward the initial position (the aperture closing position of the shutter blade 10) at the same time when the stepping motor 16 is reversed. When the driving member 2 starts rotating in the backward direction, the cam slope 21 a formed on the cam projection 21 of the driving member 2 comes into contact with the locked portion 3 a of the blade opening / closing lever 3. Then, the locked portion 3a of the blade opening / closing lever 3 is pushed up counterclockwise by the cam action.

Therefore, the blade opening / closing lever 3 rotates counterclockwise around the pivot 4 against the urging force of the first torsion spring 5, and accordingly, the blade opening / closing ring 7 also moves from the position of the open aperture opening. The shutter blade 10 is rotated clockwise toward the aperture closing position to start closing the shutter blade 10 (see FIG. 7).

At this time, in the process of the backward rotation of the driving member 2, the pushing projection 23 holding the center arm tip 123 of the locking lever 12 is held in the holding state with respect to the center arm tip 123 of the locking lever 12. Is released, the locking lever 12 returns to the initial position at this point due to the urging force of the second torsion spring 15.

However, at this time, the blade opening / closing lever 3
Of the cam member 21 of the cam member 21 of the driving member 2 has not yet reached the cam top 21b.
The locked portion 3a reaches the cam top 21b while slightly pushing up the lower arm tip 122 of the locking lever 12 clockwise on its outer surface. That is, the locking lever 12 returns to its initial position (FIG. 8).
And FIG. 9).

On the other hand, the blade opening / closing ring 7 rotates clockwise with the return operation of the blade opening / closing lever 3 to the initial position, returns to the initial position, closes the shutter blade 10, and opens the aperture. Close the front of 19. And
When the stepping motor 16 rotates in the reverse direction to the initial phase, the driving member 2 returns to the initial position. At this point, the entire shutter blade opening / closing mechanism returns to the initial state in FIG.

[Case in which the present invention is applied to the program area] The blade opening / closing lever 3 is actuated by the biasing force of the first torsion spring 5 from the position where the blade opening / closing lever 3 is locked at the tip surface of the lower arm tip 122 of the locking lever 12. Up to the stage of rapid rotation in the clockwise direction (see FIG. 4), the transition is the same as in the case of a normal shutter device.

In the case where the present invention is applied to the program area, the inversion (clockwise) start timing of the stepping motor 16 is set to a time corresponding to the subject brightness at each time. At aperture)
Is short and becomes longer as the luminance becomes lower.

Therefore, when the locking lever 12 is released from locking at the distal end surface of the lower arm distal end portion 122, the locked portion 3 a of the blade opening / closing lever 3 is moved by the urging force of the first torsion spring 5. The blade rotates clockwise toward the opening, collides with the cam slope 21a of the driving member 2 which has been reversed at a timing corresponding to the subject luminance, and the blade opening / closing lever 3 is instantaneously reversed toward the closing (counterclockwise direction). Rotation).

That is, in the case where the present invention is applied to the program area, the clockwise rotation angle of the blade opening / closing lever 3 is limited to an angle determined by collision with the cam slope 21a (see FIG. 5).

As a result, the U-shaped groove 3b of the blade opening / closing lever 3
The blade opening / closing ring 7 interlocked with the blade opening / closing lever 3 via the interlocking pin 8 rotates counterclockwise by the limited rotation angle of the blade opening / closing lever 3 at this time, and the control cam groove 10a
The shutter blades 10 are rotated in the opening direction by an angle corresponding to this rotation angle via a transmission mechanism formed by the aperture pins 9, so that the shutter blades 10 rotate clockwise relative to each other about the respective pivots 11 and are sometimes rotated. An intermediate stop aperture having a triangular waveform corresponding to the subject brightness is formed.

In this case, since the brightness of the subject changes continuously, the shape of the cam slope 21a formed on the driving member 2 changes continuously with the reversal start timing time of the stepping motor 16 which changes with the brightness of the subject at each time. This is set in consideration of the mechanical size of the intermediate aperture opening corresponding to the subject luminance which changes in a timely manner.

After the three shutter blades 10 have become aperture stops corresponding to the subject brightness at that time, the driving member 2 stops at a stop position where an intermediate aperture opening determined by the subject brightness at that time can be obtained. From the shutter blade 1 immediately after returning to the initial position by following the same process as in the case where the shutter blade 1 is applied to the open area described above.
0 is closed.

Regarding the control at the time of reversal of the stepping motor 16, the response characteristic of the stepping motor 16, the driving member 2, the blade opening / closing ring 7, the shutter blade 10 It is assumed that the control is performed by comprehensively taking into account the operating characteristics such as the above and the urging force of the first torsion spring 5.

Although the camera shutter blade opening / closing mechanism of the present invention has been described in both the case where it is applied to the open area and the case where it is applied to the program area, the present invention is not limited to the illustrated embodiment. Various modifications can be made without departing from the scope of the invention.

[0070]

As described above, according to the first aspect of the present invention, first, since the locking lever is directly pivoted to the main plate, the rotational inertia of the driving member can be reduced. As a result, it is possible to suppress the operation delay phenomenon of mechanical members due to rotational inertia within a range that does not hinder practical use, and it is possible to adopt high-precision exposure control and high-speed shutter time become. Second
The blade opening / closing lever is formed in a bell crank shape
The locked part at the end and the driving part of the blade opening / closing ring on the other arm
And a driving member side for rotating the blade opening / closing lever.
The cam slope is formed on the
The cam action is smooth, and the lens
The effect that the pace can be reduced as much as possible
can get. Third, the blade opening / closing lever and the locking lever
Are provided on the main plate so as to be disengageable, and the drive
The blade opening / closing lever up to the cam top formed on the member
In the state in which the blade opening / closing lever is rotated.
There is a gap between the locking portion and the locking end of the locking lever
The locking part of the locking lever and the blade opening / closing
Unnecessary interference occurs in the engagement of the lever with the locked part
Without the locking lever, the locking formed on the driving member
Until the lock is released by the action of the release action part
Ensuring reliable locking and improving reliability
Can be. Fourth, in the forward direction according to the shutter release
Unlocking action formed on the driving member rotating toward the front
Function of the locking lever with respect to the blade opening / closing lever.
The locking by the bar is released, and the urging force of the first urging means is released.
Moves the blade open / close lever from its initial position to the maximum
Rotate toward the rotation position and drive the driving member at the object brightness.
After turning by a fixed angle, immediately go back
There is no response delay because it is configured to be able to rotate in reverse.
A program shutter can be provided.

Further, claim 2 of the utility model registration claim
In the device of the present invention, the locking lever and the blade opening / closing lever are pivotally connected to the main plate, and the locking end (the lower arm tip) of the locking lever engages the locked portion of the blade opening / closing lever. When stopped, the locking end of the locking lever slightly protrudes into the rotational movement trajectory of the locked portion of the blade opening and closing lever, and furthermore, the blade opening and closing lever in the process of rotating the driving member in the backward direction. When the locking lever is rotated by the counterclockwise rotation of the locking lever, the locking end of the locking lever can move in a direction deviating from the rotational movement locus of the locked portion of the blade opening / closing lever. The rotation center of the lever can be set.

Therefore, during the closing process of the shutter blade, until the blade opening / closing lever reaches the pinhole position from the position of the aperture stop opening of the shutter blade, the locked portion of the blade opening / closing lever is moved to the tip of the lower arm of the locking lever. As a result, except for the adverse effect caused by the contact between the blade opening / closing lever and the locking lever on the amount of spring force of the second torsion spring, it is possible to reduce the This can eliminate the cause of the variation in exposure accuracy that occurs.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of an embodiment of a camera shutter blade opening / closing mechanism of the present invention.

FIG. 2 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 7 is an operation state diagram showing a state of the three members when the operation is performed.

FIG. 3 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 8 is an operation state diagram showing a state of three members when slightly rotated in a direction (counterclockwise).

4 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 9 is an operation state diagram showing a state of the three members after the locking of is released.

FIG. 5 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner. FIG. 9 is an operation state diagram showing a state at the moment when the blade opening / closing lever collides with a cam slope of a reversing cam projection when a predetermined aperture opening is realized.

6 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 9 is an operation state diagram showing a state of the three members when rotated to a position (a position where the shutter blade is at the open stop).

7 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 10 is an operation state diagram showing a state of the three members when slightly rotated in a backward direction (clockwise) from a position corresponding to a realized position.

8 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 13 is an operation state diagram illustrating a state of the three members when a locked portion of the blade opening / closing lever pushes up the locking lever in a process of rotating in a backward direction from a position corresponding to a realized position.

9 is an operation state diagram showing a relative operation state of a driving member, a blade opening / closing lever, and a locking lever in the camera shutter blade opening / closing mechanism of FIG. 1 in a time-series manner; FIG. 13 is an operation state diagram showing a state of the three members when the engaged state between the locked portion of the blade opening / closing lever and the locking lever is in the final state in the process of rotating in the backward direction from the position corresponding to the realized position. is there.

FIG. 10 is a schematic view for explaining a conventional shutter blade opening / closing mechanism, in which the direction of forward movement of a driving member is changed in a counterclockwise direction so as to be easily compared with the camera shutter blade opening / closing mechanism according to the present invention. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main plate 2 Drive member 21 Cam projection 21a Cam slope 21b Cam top 21c Cam bottom 22 Gear part 23 Pushing projection 3 Blade opening / closing lever 3a Locked portion 3b U-shaped groove 5 First torsion spring 6 Pin 7 Blade opening / closing ring 8 Interlocking Pin 9 Aperture pin 10 Aperture / shutter blade 10a Control cam groove 11 Axis 12 Locking lever 121 Upper arm tip 122 Lower arm tip 123 Center arm tip 123a Side face facing counterclockwise 13 Axis 14 Stopper 15 Second Torsion spring 16 Stepping motor 17 Output gear 18 Intermediate gear (two-speed reduction gear) 18a Large gear 18b Small gear 19 Aperture

Claims (2)

(57) [Scope of request for utility model registration] 1. A shutter blade reciprocatingly rotating between an aperture closing position and an open aperture opening position, a bell crank shape, and a locked portion on one arm portion, and a locked portion on another arm portion.
A drive unit for a blade opening / closing ring is provided on one of the arms, and ultimately reciprocates between an initial position corresponding to the aperture closing position of the shutter blade and a maximum rotation position corresponding to the open aperture opening of the shutter blade. A blade opening / closing lever for opening and closing the shutter blade; first biasing means for biasing the blade opening / closing lever to rotate from an initial position toward the maximum rotation position; and a biasing force of the first biasing means. In front of the blade opening / closing lever
Serial to detachably lock the locked portion in its initial position the locking end
A locking lever having a second biasing means for urging the locking lever so as to always toward its initial position, the cam top surface that is continuous with the inclined cam face and the inclined cam face is formed
It has a cam projection, and the driving member is driven to rotate in a reciprocating direction by the electric motor, met camera shutter blade opening and closing mechanism and a base plate for holding each of these members and means, the engagement between the blade opening lever a stop lever provided with a detachably engaged on the base plate, before being formed on the drive member
The blade open / close lever is turned to the top of the cam.
The locked portion of the blade opening / closing lever and the locking lever.
The gap is formed between the bar and the locking end of the bar . From this state , the cam projection slightly rotates and
Wherein the lead to the cam slope the locked portion of the locking lever
Configured to so that the locking by the locking unit, with respect to the blade opening lever by the action of the unlocking action portion formed before <br/> SL drive member rotates toward the forward direction in response to a shutter release Release the locking by the locking lever, rotate the blade opening / closing lever from its initial position toward the maximum rotation position by the biasing force of the first biasing means, and rotate the driving member by an angle determined by the subject brightness. Just rotate
A shutter blade opening / closing mechanism for a camera, wherein the shutter blade opening / closing mechanism is configured to be able to immediately reversely rotate in the backward direction after being caused to rotate . 2. The shutter blade opening / closing mechanism according to claim 1, wherein when the locking lever locks the blade opening / closing lever, a locking end of the locking lever is connected to the blade opening / closing lever. So that it slightly projects into the locus of rotational movement of the locked part of
Further, in the process of rotating the driving member in the backward direction, the locking end of the locking lever is returned from the rotational movement trajectory of the locked portion of the blade opening / closing lever by the return operation of the blade opening / closing lever to the initial position. A shutter blade opening / closing mechanism for a camera, wherein a rotation center of the locking lever is set so that the locking lever can move in a direction in which the locking lever is disengaged.