JP3448366B2 - Lens shutter for camera with lens drive 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 lens shutter for a camera having a lens driving mechanism.

[0002]

2. Description of the Related Art A driving member is interlocked with a motor that reciprocates within a predetermined angle range depending on a direction of energization, and the driving member actuates a lens feeding member rotatable about an optical axis and opening / closing a shutter. A lens shutter for a camera adapted to operate is known, and an example thereof is disclosed in Japanese Patent Publication No. 3-105333. In the conventional shutter of this kind, a spring for returning is hooked on the lens feeding member. Therefore, at the time of focus adjustment, the driving member rotates the lens moving-out member against the biasing force of the spring via the ratchet member. A cam portion is provided on the lens feeding member, and the lens barrel is moved in the optical axis direction by the cam surface. Therefore, the lens feeding member is locked at the focus adjustment position during photographing, and is unlocked after the photographing is completed to return to the original position.

[0003]

However, in the above-mentioned conventional example, in order to prevent the lens barrel from moving inadvertently, the lens barrel has a fairly strong spring force against the cam surface. It is in contact with. Moreover, since the lens extension member changes the rotational movement into the linear movement of the lens barrel as described above, a considerable force is required to rotate the lens extension member. In addition, as described above, the spring must be rotated against the return spring to the original position, and the load on the motor becomes extremely large.

Further, in the conventional example, the lens feeding operation is performed by the reciprocating movement in one direction from the initial position of the motor, and the opening and closing operation of the shutter blade is performed by the reciprocating movement in the other direction. It was difficult to accurately turn the drive member back at the initial position of the motor during the feeding operation of the above, and there was a risk of overrun and opening and closing of the shutter blades. for that reason,
There was a problem in that the position of the motor and the electrical adjustment had to be performed during manufacture.

The present invention has been made in order to solve such a problem, and its purpose is to rotate the lens feeding member only in one direction so that the lens is moved to the original position. It is an object of the present invention to provide a lens shutter for a camera provided with a lens driving mechanism that does not require a return spring and can reduce a load on a motor.

Further, another object of the present invention is to prevent the shutter from being opened and closed even if the lens passes the initial position from one end to the other end of the operating angle range during the lens advancing operation. It is an object of the present invention to provide a lens shutter for a camera provided with a lens driving mechanism in which the shutter blade is opened and closed only when it is stopped at the initial position and then started toward the other end.

[0007]

In order to achieve the above object, a lens shutter for a camera provided with a lens driving mechanism according to the present invention is started from an initial position in accordance with an energizing direction and reciprocates within a predetermined angular range. A driving motor, a driving means that reciprocates in conjunction with the motor, and a lens feeding means that has a circular cam surface and moves the lens barrel in the optical axis direction by rotating about the optical axis. An opening / closing means for opening and closing the shutter blades by the driving means, a feeding means composed of a ratchet mechanism for reciprocatingly interlocking with the driving means to intermittently rotate the lens feeding means in one direction, and one of the driving means. Regulating means that is moved against the urging force by the movement in the direction, and a locking hand that can lock the regulating means to return to the original position by the urging force at an intermediate position. When, wherein the drive means, when said locking means is Kakarise' said regulating means, through said feeding means by the reciprocating rotating the lens feeding means, said locking means said regulating means when not Kakarise' is adapted to actuate said closing means.

Further, preferably, in a lens shutter for a camera equipped with a lens driving mechanism according to the present invention, an initial position of the motor is between both operating ends in a predetermined angle range, and the locking means is the motor. Starts from the initial position toward one operating end, and when returning to the other operating end toward the other operating end, the regulating means is locked, and the motor operates from the initial position to the other operating end. When starting toward the end, the restriction means is not locked.

Further preferably, in the lens shutter for a camera provided with the lens driving mechanism according to the present invention, the feeding means is interlocked with the first pawl mechanism operated by the driving means and the first pawl mechanism. A second pawl mechanism that is operated, and these two pawl mechanisms rotate the lens feeding means by alternately pushing ratchet teeth, and the cam surface provided on the lens feeding means is The inclined surface portions and the flat surface portions are alternately formed, and the heights are sequentially different in the optical axis direction.

[0010]

When the release button of the camera is pressed, the distance measuring device and the exposure amount measuring device are activated, and the motor is energized.
This motor is a type of motor that can reciprocate within a predetermined angle range from the initial position according to the energization direction, and reciprocates from the initial position toward one working end according to the subject distance by the energization. repeat. The angular range of this reciprocating motion is mechanically determined, and the operation toward the other end beyond the initial position is restricted by the position of the locking means that engages with the restriction means. Therefore, the shutter blades are not opened or closed at this stage. The reciprocating motion of the motor is transmitted to the first pawl mechanism and the second pawl mechanism which is interlocked with the first pawl mechanism, and these pawl mechanisms alternately rotate the lens feeding means. After rotating the lens feeding means according to the measurement distance, the motor once returns to the initial position and stops.

After that, the motor starts again, but this time toward the other working end. At this time, the driving means is not regulated by the locking means as described above, but operates greatly to operate the opening / closing means to open the shutter blades.
Then, after a predetermined time, the motor returns to the initial position and the shutter blades are closed. In the process of opening the shutter blades, the second pawl mechanism slightly rotates the lens feeding means,
The cam surface provided on the lens feeding means is formed with a slope portion and a flat portion alternately, and the rotation is performed in the flat portion, and the lens barrel is not extended. After the opening / closing operation of the shutter blades or in conjunction with the winding of the film, the motor repeats the reciprocating motion toward one of the operating ends, and the lens feeding means is operated to the next photographing standby position and stopped.

[0012]

Embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of the present embodiment and shows an initial state of operation, but at the same time shows an intermediate state of a series of operations. FIG. 2 is a cross-sectional explanatory view for facilitating understanding of the overlapping relationship between the respective members shown in FIG. FIG. 3 is a plan view showing a state where the lens feeding member is fed by one claw lever, and FIG. 4 is a plan view showing a state where the lens feeding member is fed by the other claw lever. Figure 5
[Fig. 6] is a plan view showing a state where a shutter blade is opened, and Fig. 6 is an explanatory view showing a shape of a cam surface of a lens feeding member.

First, the configuration of this embodiment will be mainly described with reference to FIGS.
Will be explained. The shutter base plate is composed of a front base plate 1 and a back base plate 2 made of synthetic resin, and the blade chambers of the shutter blades 3 and 4 are formed between them. Both main plates 1 and 2
Although circular openings 1a and 2a centering on the optical axis 0 are formed in the optical disk 1, the diameter of the opening 1a is smaller and the opening 1a is used as an exposure opening. No optical axis on front plate 1
A cylindrical portion 1b is formed around the center of the lens, and a lens feeding member 5 is rotatably fitted to the outer peripheral portion thereof with a predetermined frictional force.

The lens feeding member 5 is prevented from coming off in the optical axis direction by a well-known means, and ratchet teeth 5a are formed on the outer peripheral portion thereof.
Three cam portions 5b are formed every 120 degrees. As shown in FIG. 6, each of the cam portions 5b is alternately formed with a slope portion and a flat portion so that the height in the optical axis direction is sequentially changed as a whole. As is well known, three pins P provided on a lens barrel (not shown) come into contact with each other. Further, the lens advancing member 5 is not biased by a spring or the like in the rotational direction, and the pin P can be returned to the initial position every 120 degrees of rotation.

On the other hand, the shutter blades 3 and 4 are pivotally attached to shafts 1c and 1d which are planted on the surface plate 1 toward the blade chamber. The opening / closing lever 6 is pivotally attached to a shaft 2b planted on the back surface of the backing plate 2, and its pin 6a is fitted into the slots 3a, 4a of the shutter blades 3, 4. The open / close lever 6 is provided with a left turning property by a spring 6b in FIG. 1, but is restrained by a stopper 2c provided on the backing board 2. As can be seen from such a configuration, when the opening / closing lever 6 is rotated rightward against the spring 6b, the shutter blades 3 and 4 are opened, and when the restoring force of the spring 6b rotates leftward, the shutter blades 3 and 4 are closed. .

As a driving source for actuating the lens feeding member 5 and the opening / closing lever 6 as described above, a motor (referred to as an iris motor or a moving magnet type motor) that reciprocates within a predetermined angle range according to the energizing direction is used. Are known. In the present embodiment, such a motor 7 is attached to the back of the backing plate 2. Since the structure of the motor 7 is well known, the detailed description of the structure is omitted. However, the rotor 7a is composed of two-pole permanent magnets, and the position of the rotor 7a when the coil is not energized in the stator. The magnetic member 7b capable of restricting the Further, a driving member 7c is integrally provided on the rotor 7a, and the tip of the driving member 7c penetrates the back plate 2 and the front plate 1 as shown in FIG. It is sticking out.

On the other hand, the shafts 1e and 1f planted in the front ground plate 1
A first actuating lever 8 and a second actuating lever 9 are pivotally attached to each other, and a pin 8a of the first actuating lever 8 is fitted in a slot 9a of the second actuating lever 9. Both operating levers 8, 9
Claw levers 10 and 11 are pivotally attached to the shafts 8b and 9b, respectively, and the right turning habit is imparted by the springs 10a and 11a, respectively. It is restrained by the stoppers 8c and 9c. The tip of the pawl lever 10.11 meshes with the ratchet teeth 5 a of the lens feeding member 5. Further, a bifurcated portion 8d is formed on the first actuating lever 8 and holds the tip of the drive member 7c described above. The counterclockwise rotation of the operating lever 8 is restricted by a stopper 1g that is planted in the front ground plate 1.

Further, on the surface plate 1, a regulating member 12 is rotatably attached to a shaft 1h which is planted substantially coaxially with the motor 7, and a locking lever 13 is pivotally attached to the shaft 1i. There is. An arcuate window 12a that penetrates the drive member 7c is formed in the restriction member 12, and the large diameter surface 12 is formed on the peripheral surface.
b, the small diameter surface 12c, the engaging portions 12d, 12e are formed,
Left-handedness is imparted by the spring 12f. Also,
Locking portions 13a and 13b are formed on the locking lever 13,
The pin 13c is planted and the right turning property is imparted by the spring 13d.

Next, the operation of this embodiment will be described. Hold the camera and press the shutter button to close the power switch at the initial stage and measure the distance. At this time, a current flows through the coil (not shown) of the motor 7 in the forward direction first, and the rotor 7a rotates clockwise in the initial state of FIG.
Thereby, the drive member 7c rotates the first operating lever 8 counterclockwise and interlocks with it to rotate the second operating lever 9 clockwise. Therefore, the pawl lever 10 pushes the ratchet teeth 5a at the tip to rotate the lens feeding member 5 clockwise.
At this time, No. 1 is pushed by the ratchet teeth 5a and turns left by the shaft 9b while tensioning the spring 11a, so that it is irrelevant to the lens feeding operation.

At this time, the drive member 7c is, on the other hand,
By pressing the window 12a, the regulating member 12 is moved to the spring 1
Turn right against 2f. Then, the locking lever 13
The locking portion 13b is rotated counterclockwise by being pushed by the engaging portion 12e, but the large diameter portion 12b is immediately released by the spring 13d.
Contact with. The clockwise rotation of the drive member 7c is stopped by the counterclockwise rotation of the first operating lever 8 coming into contact with the stopper 1g, and the state shown in FIG. 3 is obtained.

In the state of FIG. 3, once the energization of the coil of the motor 7 is cut off and a current is immediately applied in the opposite direction, the rotor 7a starts left-handed rotation. Thereby, the first
The operating lever 8 rotates right and the second operating lever 9 rotates left.
Therefore, this time, the pawl lever 11 pushes the ratchet teeth 5a at its tip to rotate the lens feeding member 5 clockwise, and the pawl lever 10 only rotates counterclockwise by the shaft 8b against the spring 10a.

In the course of such an operation, on the other hand, the regulating member 12 also rotates counterclockwise according to the counterclockwise rotation of the drive member 7c, but the engaging portion 12e thereof is the engaging portion 1 of the engaging lever 13.
By being locked by 3b, it is once stopped. After that, the first actuating lever 8 still rotates clockwise, pushes the pin 13c of the locking lever 13, and moves the locking lever 13 to the spring 13
Rotate counterclockwise against d. Therefore, the locking by the locking portion 13b is released, and the restricting member 12 rotates counterclockwise again, but at that time, the locking portion 13a of the locking lever 13 has already been locked.
Since it is within the operation locus of d, it is stopped by being locked by the locking portion 13a. This state is shown in FIG. 4, but in this state, the drive member 7c is at a position where it has passed the initial position toward the other end of the operating angle range, and the locking portion 13a is the regulating member 12a. By making contact with the large-diameter portion 12b of the above, further left-handed rotation is prevented.

Thereafter, in this manner, the currents in the forward and reverse directions are alternately applied to the coil of the motor 7 to repeat the operation between the position shown in FIG. 3 and the position shown in FIG. Let 5 continue turning right. By this clockwise rotation, the cam portion 5b of the lens feeding member 5
A lens barrel (not shown) will be extended. Needless to say, the lens barrel may not be extended depending on the subject distance.

FIG. 6 shows a contact state between the pin P protruding from the lens barrel in the optical axis direction and the cam portion 5b. As described above, since the three cam parts 5b are provided in the range of 120 degrees, three pins P are also provided, and each pin P is in contact with each cam part 5b. , This set is shown in the expanded state. Then, as described above, when the lens feeding member 5 is rotated rightward, the cam portion 5b should normally move to the left side of the figure with respect to the pin P, but in order to make it easy to understand, the relative movement should be made. The pin P is shown as if it were moving to the right. In the figure, the position indicated by the solid line of the pin P is the initial position, that is, the position corresponding to FIG. 1, the position corresponding to FIG. 3 is the a position in the middle of the slope portion, and the position corresponding to FIG. 4 is the slope surface. It is the b position that has gone up the section.

In this way, when the lens barrel reaches the extended position corresponding to the distance measurement, the forward and reverse energization of the coil of the motor 7 for extending the lens is cut off. Since the rotor 7a is a permanent magnet, it is attracted by the magnetic member 7b by the attraction action of its N pole and the magnetic member 7b, and always returns to the position shown in FIG. At this time, in FIG.
The pin P is located at a plane portion position, for example, the position c, which is slightly advanced after going up the slope portion of the cam portion 5b. Then, the next exposure operation is performed from this state.

In order to open and close the shutter blades 3 and 4, in this state, the coil of the motor 7 is energized in the reverse direction to rotate the rotor 7a counterclockwise. Therefore, the first operating lever 8 is rotated clockwise by the drive member 7c, and the pin 13
Press c and rotate the locking lever 13 counterclockwise against the spring 13d. At this time, the locking portion 13a is the small diameter portion 1 of the regulating member 12.
Since it is opposed to 2c, the locking lever 13 is in a state in which it can be rotated counterclockwise to a greater extent than when the lens is extended. Therefore, the first actuating lever 8 is largely turned to the right and the driving member 7c is largely turned to the left as compared with when the lens is extended.

The drive member 7c rotates the open / close lever 6 clockwise by this large counterclockwise rotation. Therefore, the shutter blades 3 and 4 are opened and brought into the state shown in FIG. As described above, in the process from the state of FIG. 1 to the state of FIG. 5, the second actuation lever 9 is turned to the left by the right turn of the first actuation lever 8, and the lens feeding member 5 is turned to the right via the pawl lever 11. Become. However, since this right rotation corresponds to one ratchet tooth 5a, only the pin P moves from the c position to the d position in FIG. Therefore, since the pin P is on the same plane, it does not affect the amount of extension of the lens barrel.

When the coil of the motor 7 is energized in the positive direction after a predetermined time, the rotor 7a and the driving member 7c rotate right. Therefore, the opening / closing lever 6 follows the biasing force of the spring 6b to close the shutter blades 3 and 4, and
The movement is stopped by the stopper 2c. In the closed course of the shutter blades 3 and 4, the first actuating lever 8 is left-handed, but will be right- member 5 feeding the lens by the pawl lever 10, the pin P is still the flat portion of the cam portion 5b There is no problem because the exposure will be completed in a while. When the driving member 7c reaches the position shown in FIG. 1, the coil of the motor 7 is de-energized. At that time, even if there is a slight deviation in the stop position, the rotor 7a and the magnetic member 7b are stopped at a predetermined position by the attraction force as described above. Then, in conjunction with the film winding operation, the coil of the motor 7 is energized again, and the driving member 7c reciprocates between the positions shown in FIGS. The next cam part 5
It will be made to stand by in the initial position of b.

In the above embodiment, the drive member 7
Although c is completely integrated with the rotor 7a, there is no particular need to have such a configuration, and any form may be used as long as it is a member that moves integrally with the rotor 7a. Absent. Further, the first operating lever 8 is adapted to engage with the pin 13c of the locking lever 13, but the driving member 7
You may make it deform | transform c and make the drive member engage directly. Further, the ratchet mechanism is composed of a first pawl mechanism including a first operating lever 8 and a pawl lever 10, and a second pawl mechanism including a second operating lever 9 and a pawl lever 11, but only the first pawl mechanism. It does not prevent you from configuring with. However, in that case, one ratchet tooth 5a is fed by the reciprocating movement of the driving member 7c. Further, the ratchet teeth 5a are not provided on the lens payout member 5, but a gear screwed with the lens payout member 5 is interposed,
It may be provided on the gear.

[0030]

As described above, according to the present invention, since it is not necessary to provide a spring for returning to the initial position in the lens feeding member, it is possible to reduce the load on the motor and to design the motor. And it becomes advantageous in cost. Moreover, since the operating angle of the drive member is actively regulated during the lens extension operation, there is no need to make adjustments so that the shutter blades are not opened and closed by mistake, and the operating angle is increased. It is also possible.

[Brief description of drawings]

FIG. 1 is a plan view showing an initial state and an intermediate state of operation of an embodiment of the present invention.

FIG. 2 is a cross-sectional explanatory view for making it easier to understand the overlapping relationship between the respective members shown in FIG.

FIG. 3 is a plan view showing a state in which a lens feeding member is fed by one claw lever.

FIG. 4 is a plan view showing a state where the lens feeding member is fed by the other claw lever.

FIG. 5 is a plan view showing a state in which shutter blades are opened.

FIG. 6 is an explanatory diagram showing a shape of a cam surface of a lens feeding member.

[Explanation of symbols]

0 optical axis 1 front ground plate 2 Lining board 3,4 shutter blades 5 Lens extension member 5a ratchet teeth 5b Cam part 6 open / close lever 6b, 10a, 11a, 12f, 13d springs 7 motor 7a rotor 7b Magnetic member 7c drive member 8 First actuating member 8d Bifurcated part 9 Second operating lever 10,11 Claw lever 12 Control member 12a window 12b Large diameter part 12c small diameter part 12d, 12e engaging part 13 Locking lever 13a, 13b Locking part

Claims (3)

(57) [Claims] 1. A motor having a motor that starts from an initial position and reciprocates within a predetermined angle range in accordance with a direction of energization, a driving unit that reciprocates in conjunction with the motor, and a cam surface formed in a circular shape. A lens feeding means for moving the lens barrel in the optical axis direction by rotating about the optical axis, an opening / closing means for opening / closing the shutter blades by the driving means, and a lens feeding means reciprocatingly linked with the driving means. Feeding means for intermittently rotating the ratchet mechanism in one direction, regulating means that is moved against the biasing force of the driving means in one direction, and the regulating means is in the original position by the biasing force. and a locking means can be locked in the middle position to return to the drive means, said feeding means, the by the reciprocating when said locking means is Kakarise' said regulating means Rotating the lens feeding means via the camera the locking means when no Kakarise' to the regulating means, provided with a lens driving mechanism, characterized in that so as to open and close the shutter blade is operated with the switching means Lens shutter for. 2. The initial position of the motor is between both operating ends in a predetermined angle range, and the locking means starts the motor from the initial position toward one of the operating ends, and when the motor is returning, When the initial position is passed toward the other operating end, the restricting means is locked, and when the motor is started from the initial position toward the other operating end, the restricting means is not locked. A lens shutter for a camera provided with the lens driving mechanism according to claim 1. 3. The feeding means includes a first pawl mechanism operated by the drive means and a second pawl mechanism operated in conjunction with the first pawl mechanism, and these two pawl mechanisms are provided. The lens feeding means is rotated by alternately pushing ratchet teeth, and the cam surface provided on the lens feeding means has sloped portions and flat portions alternately formed. 2. The heights are sequentially different with respect to the direction.
Alternatively, a lens shutter for a camera including the lens driving mechanism according to item 2.