JP5366397B2 - Shutter device and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the situation where attracting surface of an electromagnet (yoke) and an armature become rough in a shutter device. <P>SOLUTION: The shutter device 113 includes a blade driving member 20, which is equipped with the armature 23 and drives shutter blades 2 to 5, the electromagnets 26 and 27 which are energized to attract the armature to hold the blade driving member at a drive preparing position, and release attraction, when energizing is stopped, to start drive of the shutter blade by the blade driving member, and a set member 18, which moves the blade driving member having driven the shutter blade to a set position across the drive preparing position. A braking member 37 decreases the moving speed of the blade driving member, before the armature abuts against the electromagnet in the middle of setting operation, to prevent movement in the blade driving direction across the drive preparing position of the blade driving member, until the blade driving member moves from the set position to the drive preparing position. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a shutter (focal plane shutter) device used in an imaging device such as a digital single-lens reflex camera.

  The shutter blades for the front curtain and the rear curtain of the focal plane shutter are each driven by a blade driving member biased by a drive spring. Further, the blade driving members for the front curtain and the rear curtain are held by the front curtain and rear curtain electromagnetic magnets at the respective drive preparation positions before the start of driving. Then, by sequentially stopping energization of these electromagnetic magnets at a predetermined timing, first, driving of the front curtain shutter blades by the front curtain blade driving member is started, and then the rear curtain shutter blades are used for the rear curtain. Driving by the blade driving member is started.

  After the front and rear curtain shutter blades have traveled in this manner, the set member is operated, and each blade driving member is moved together with each shutter blade against the biasing force of the driving spring (while charging the driving spring). ) A setting operation for returning to the direction of the drive preparation position is performed.

  In this setting operation, it is necessary to securely contact the armature provided on the blade driving member with the yoke of the electromagnetic magnet. For this reason, the armature is attached to the blade driving member via an armature spring. After the blade drive member is moved by the set member to the drive preparation position where the armature contacts the yoke of the electromagnetic magnet, the armature spring is charged and further moved to the set position (overcharge position) slightly exceeding the drive preparation position. Let

  The set member that has moved the blade driving member to the set position in this manner remains in the operating position until immediately before the next shutter blade travels. This is because energization of the electromagnetic magnet is performed immediately before starting the next shutter blade for power saving. For this reason, at the set position, the urging force in the blade driving direction by the charged drive spring and the armature spring acts on the blade driving member.

  In the next shooting, first, the electromagnetic magnet is energized to attract the armature, and then the set member is returned to the initial position before the set operation. At this time, the blade driving member that has received the urging force of the driving spring and the armature spring moves slightly from the set position, and stops at the driving preparation position due to the armature suction by the electromagnetic magnet. Thereafter, the energization of the electromagnetic magnet is cut off in response to a signal from the release switch, and the driving of the shutter blades by the blade driving member is started by the biasing force of the driving spring.

  The returning operation of the set member to the initial position is performed at high speed. For this reason, the blade drive member also moves from the set position to the drive preparation position in a short time of several ms. At this time, a large impact force is instantaneously applied to the armature biased by the drive spring and the armature spring. When the armature is removed from the magnet by the impact force, the shutter blades are started to be driven by the blade driving member, and accurate shutter speed control cannot be performed. Therefore, in the past, sufficient power was supplied to the electromagnetic magnet to generate a sufficient attracting force that can withstand the impact force.

  However, increasing the power supplied to the electromagnetic magnet is contrary to the requirement for camera power saving. For this reason, it is required to prevent the armature from being attracted by the electromagnetic magnet even by an impact force while suppressing the power supplied to the electromagnetic magnet.

  In the shutter device disclosed in Patent Document 1, a pressing member is provided for pressing the armature against the electromagnetic magnet until the blade driving member moves from the setting position and stops at the driving preparation position. The push is released in conjunction with the return.

  Further, the shutter device disclosed in Patent Document 2 is provided with a pressing spring that presses the armature against the electromagnetic magnet until the blade driving member stops at the driving preparation position. An armature spring disposed between the blade driving member and the armature is also used as the holding spring.

  Further, in the shutter device disclosed in Patent Document 3, the blade driving member is provided with a mechanism for absorbing overcharge after the yoke of the electromagnetic magnet and the armature come into contact during the setting operation. Then, after the setting operation, a member that restricts the returning operation of the setting member to the initial position is provided until the blade driving member moves to the driving preparation position, and the setting member directly holds the blade driving member at the driving preparation position.

Furthermore, in the shutter device disclosed in Patent Document 4, the biasing force of the main drive spring that biases the blade drive member is set small by providing an auxiliary drive member that is biased by the auxiliary drive spring. When the blade driving member moves from the set position to the driving preparation position, the impact applied to the armature by the urging force of each driving spring is generated at different timings.
JP-A-9-304807 JP-A-9-304808 Japanese Patent Laid-Open No. 10-48699 JP 2000-075356 A

  However, since the urging force of the drive spring is large in the shutter device disclosed in Patent Document 1, in order to stop the armature at the attracting position by the electromagnetic magnet, the pressing member is increased in rigidity to increase the pressing force. There is a need. In this case, after the contact between the yoke of the electromagnetic magnet and the armature, a certain movement stroke is required to press the armature against the yoke by the pressing member. For this reason, there is a high possibility that the armature and the suction surface of the yoke will be twisted (sliding) due to the pressing force of the pressing member within the moving stroke.

  In the shutter device disclosed in Patent Document 2, the impact force generated in the armature is reduced by the balance between the biasing force of the pressing spring and the biasing force of the drive spring. However, in order to obtain such an effect, it is necessary to set the biasing force of the holding spring to a certain level with respect to the large biasing force of the drive spring, and a certain amount of movement for pressing the armature against the yoke. Stroke is necessary. Therefore, similarly to the shutter device disclosed in Patent Document 1, during the stroke for pressing the armature after the contact between the yoke and the armature, the armature and the yoke are moved by the large pressing force of the pressing spring within the moving stroke. There is a high possibility that the adsorption surface will be distorted.

  Further, in the shutter device disclosed in Patent Document 3, since the blade driving member is provided with a mechanism for absorbing overcharge after the yoke and the armature contact each other, an armature spring is not necessary. However, this causes a large urging force of the drive spring to be applied to the armature and brought into contact with the yoke during overcharging. For this reason, there is a high possibility that the adsorption surface between the yoke and the armature will be twisted.

  As in the shutter devices disclosed in Patent Documents 1 to 3, if the suction surface between the yoke and the armature is twisted every time the shutter operation is performed, the suction surface is worn and roughened, which may cause a suction failure.

  Further, in the shutter device disclosed in Patent Document 4, since the auxiliary driving member that is urged by the auxiliary driving spring applies an unnecessary urging force to the blade driving member even after the contact between the yoke and the armature, The drive member is deformed. As a result, the equalizing property of the adsorption by the electromagnetic magnet is lowered, and the accuracy of the shutter speed control is deteriorated.

  By the way, cameras tend to require a continuous shooting function at a higher speed. Accordingly, the set operation needs to be performed at a higher speed, and the blade driving member having the armature moves toward the set position at a very high speed. Therefore, the armature collides with the yoke of the electromagnetic magnet vigorously during the setting operation. As a result, the suction surfaces of the yoke and the armature become rough due to cutting or the like for each shutter operation, and there is a risk that suction failure will occur. Further, the scraped surface of the suction surface may adhere to the surface in the photographing optical path and appear in the photographed image.

  In the present invention, the operation of the blade driving member is started by the impact applied to the armature when moving from the set position to the drive preparation position while avoiding the roughening of the attracting surface of the electromagnetic magnet (yoke) and the armature. A shutter device capable of preventing this is provided.

A shutter device according to one aspect of the present invention includes a shutter blade, an armature, a blade driving member that drives the shutter blade, and attracts the armature by energization to hold the blade driving member in a driving preparation position. An electromagnetic magnet that releases the suction by stopping energization and starts driving the shutter blades by the blade driving member from the drive preparation position; and the blade driving member that has driven the shutter blades at the drive preparation position. A set member that performs a set operation of moving beyond the set position, and before the armature contacts the electromagnetic magnet from the middle of the set operation, the blade drive member contacts the blade drive member to reduce the moving speed of the blade drive member After that, contact with the blade driving member immediately before the armature contacts the electromagnetic magnet. A reduction unit that dividing the blade drive direction in which the blade drive member in a state in which the electromagnet is energized exceeds the drive preparation position of the blade driving member until moved to the drive preparation position from the set position a braking member that movement preventing portion is formed to prevent movement of the characterized by having a.

  Note that an imaging device including the shutter device also constitutes another aspect of the present invention.

  According to the present invention, even if most of the setting operation is performed at high speed, the speed of the blade driving member (that is, the armature) is reduced by the braking member when the armature contacts the electromagnetic magnet (yoke). For this reason, it is possible to avoid the armature and the attracting surfaces of the electromagnetic magnet from becoming rough while performing the setting operation at high speed. Therefore, it is possible to stably perform highly accurate shutter speed control.

  Moreover, even if the suction by the electromagnetic magnet is temporarily removed due to the impact applied to the armature when the blade drive member moves from the set position to the drive preparation position, the blade drive from the drive preparation position of the blade drive member by the braking member Movement in the direction is prevented. Then, the armature can be attracted again by the electromagnetic magnet. For this reason, the power supplied to the electromagnetic magnet can be kept low.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration of a digital single-lens reflex camera (imaging device) equipped with a shutter device according to an embodiment of the present invention.

  In FIG. 1, reference numeral 101 denotes a digital single-lens reflex camera (camera body), and reference numeral 102 denotes an interchangeable lens that is detachably attached to the camera 101. An imaging optical system 103 is accommodated in the interchangeable lens 102. The interchangeable lens 102 is electrically and mechanically connected to the camera 101 via a mount mechanism (not shown). The photographing optical system 103 includes a zoom lens and a focus lens, and zooming and focus adjustment can be performed by moving these in the direction of the optical axis L1.

  Reference numeral 106 denotes an image sensor composed of a CCD sensor or a CMOS sensor, and is housed in a package 124. In the imaging optical path from the imaging optical system 103 to the imaging element 106, a main mirror 111, a sub mirror 122, which will be described later, a focal plane shutter (hereinafter simply referred to as a shutter) that is a shutter device, an optical low pass, and an infrared cut filter 156 are provided. ing.

  The main mirror 111 is disposed in the imaging optical path together with the sub mirror 122 when the subject is observed with the optical viewfinder. The main mirror 111 disposed in the imaging optical path reflects part of the light beam from the imaging optical system 103 and transmits the other part. The light beam reflected by the main mirror 111 forms a subject image on the focus plate 105. Further, the light beam that has passed through the focusing screen 105 is guided to the user's eyes via the pentaprism 112 and the eyepiece lens 109. As a result, the subject can be observed with the optical viewfinder.

  The light beam transmitted through the main mirror 111 is reflected by the sub mirror 122 and guided to the focus detection unit 121. The focus detection unit 121 obtains the defocus amount of the imaging optical system 103 by a phase difference detection method. The focus lens drive amount for obtaining the focus is calculated from the defocus amount, and the focus lens can be moved according to the drive amount to obtain the in-focus state.

  The main mirror 111 and the sub mirror 122 are retracted outside the imaging optical path during imaging. The light beam from the imaging optical system 103 passes through openings or slits formed by the shutter blades 2 to 5 and 10 to 13 in the shutter 113 to form a subject image on the imaging element 106. The subject image is converted into an electric signal by the photoelectric conversion action of the image sensor 106. The electrical signal is converted into an image signal by an image processing circuit (not shown) and displayed on the rear display 107 or recorded on a recording medium such as a semiconductor memory. The rear display 107 is composed of a self-luminous element such as a liquid crystal panel or an organic EL.

  Reference numeral 119 denotes a main switch for starting the camera 101, and reference numeral 180 denotes an in-finder display device for displaying various information in the optical viewfinder.

  Next, the configuration of the shutter 113 will be described with reference to FIGS. 2 to 5 illustrate the configuration of the shutter 113 viewed from the opposite side (or the imaging element side) of the imaging element 106 by cutting it in half in the long side direction of the imaging element 106. FIG. 2 shows a state immediately before the armature contacts the yoke during the setting operation described later. FIG. 3 shows an overcharge state in which the set operation has been completed (a state in which a leading blade and a trailing blade driving member described later have reached an overcharge position as a set position). FIG. 4 shows a state in which the leading blade and trailing blade driving members are in the process of shifting from the overcharge position to a driving preparation position described later. FIG. 5 shows a state where the leading blade and trailing blade driving members have completed the transition from the overcharge position to the driving preparation position.

  In these drawings, reference numeral 1 denotes a substrate having a shutter opening 1a (hereinafter referred to as a shutter base plate). Reference numeral 1 b denotes a leading blade driving pin 20 c provided on a leading blade driving member 20 (member for driving the leading blade shutter blade by a spring force: hereinafter referred to as a leading blade driving member) 20 projects to the opposite side of the shutter base plate 1. This is a long hole. Reference numeral 1c denotes a rear curtain blade driving member (refer to FIG. 3) 29c provided on a rear curtain blade driving member 29 (a member for driving the rear curtain shutter blade by a spring force; hereinafter referred to as a rear blade driving member) 29 as a shutter base plate. 1 is a long hole for projecting to the opposite side of 1.

  Reference numerals 2 to 5 denote shutter blades for the front curtain, of which 2 is a front slit forming blade and 3 to 5 are front cover blades. These shutter blades 2 to 5 for the front curtain are rotatably attached to two front blade arms (not shown) provided on the opposite surface side of the shutter base plate 1, and the two front blade arms And a parallel link. Of the two leading blade arms, the main arm is rotatably attached to a shaft 1d provided on the shutter base plate 1, and is connected to the leading blade driving pin 20c of the leading blade driving member 20 described above. The leading blade driving member 20 is also rotatably attached to the shaft 1d. When the leading blade driving member 20 rotates, the main arm rotates around the shaft 1d. The slave arms of the two leading blade arms are rotatably attached to a shaft (not shown) provided on the shutter base plate 1 and rotate together with the main arm so that the leading blade shutter blades 2 to 5 are parallel to each other. Move.

  Reference numerals 10 to 13 denote shutter blades for the rear curtain, of which 10 is a rear slit forming blade and 11 to 13 are rear cover blades. These rear curtain shutter blades 10 to 13 are rotatably attached to two rear blade arms (not shown) provided on the opposite surface side of the shutter base plate 1, and the two rear blade arms are mounted. And a parallel link. Of the two rear blade arms, the main arm is rotatably attached to a shaft 1e provided on the shutter base plate 1, and is connected to the rear blade driving pin 29c of the rear blade driving member 29 described above. The rear blade drive member 29 is also rotatably attached to the shaft 1e, and the main arm rotates about the shaft 1e as the rear blade drive member 29 rotates. The slave arms of the two rear blade arms are rotatably attached to a shaft (not shown) provided on the shutter base plate 1 and rotate together with the main arm to parallel the rear curtain shutter blades 10 to 13. Move.

  The cover plate (not shown) has an opening corresponding to the shutter opening 1a, and sandwiches the shutter blades 2-5, 10-13 for the front curtain and the rear curtain between the shutter base plate 1.

  Reference numeral 18 denotes a charge lever as a set member. The charge lever 18 is rotatably attached to a shaft 1 h provided on the shutter base plate 1. The charge lever 18 includes an input arm portion 18a, an input pin 18b provided integrally with the input arm portion 18a, a leading blade output arm portion 18c, and a trailing blade output arm portion 18d. Each of these output arm portions 18c and 18d has a first cam portion (first region) 18e and 18f (see FIG. 3 for 18f) that extends radially around the shaft 1h, and an arc shape around the shaft 1h. And second cam portions (second regions) 18g and 18h extending in the vertical direction.

  The first cam portions 18e and 18f rotate the blade driving members 20 and 29 largely (by the first movement amount) with respect to the unit rotation angle (unit operation amount) of the charge lever 18. On the other hand, the second cam portions 18g and 18h rotate the blade driving members 20 and 29 small (with a second movement amount smaller than the first movement amount) with respect to the unit rotation angle of the charge lever 18. When the rotation amount of the blade driving members 20 and 29 with respect to the unit rotation angle of the charge lever 18 is the charge efficiency, the charge efficiency of the first cam portions 18e and 18f is relatively large, and the second cam portions 18g and 18g It can be said that the charge efficiency of 18h is relatively small.

  The first cam portions 18e and 18f are disposed in front of the positions where the armatures 23 and 32 abut the yokes 26 and 35 on the blade driving members 20 and 29 that have finished driving the shutter blades 2 to 5 and 10 to 13 (see FIG. 2). Rotate at high speed to return to). Subsequently, the second cam portions 18g and 18h rotate the blade driving members 20 and 29 by a small angle to the overcharge position as the set position. By providing the second cam portions 18g and 18h, the overcharge positions of the blade driving members 20 and 29 can be stabilized. The output arm portions 18c and 18d smoothly transition from the state in which the blade driving members 20 and 29 are driven by the first cam portions 18e and 18f to the state in which they are driven by the second cam portions 18g and 18h. A curved surface portion for forming the surface is formed.

  The charge lever 18 abuts against a stopper (not shown) at the position shown in FIG. 3 (overcharge position) and is prevented from further rotation.

  The charge lever 18 also has a function of shifting a braking member, which will be described later, between a state of acting on the blade driving members 20 and 29 and a state of not acting on the blade driving members 20 and 29 by the operation thereof. With such a configuration, the number of parts constituting the shutter 113 can be reduced, and the configuration can be simplified.

  The leading blade drive member 20 is rotatably attached to the shaft 1d provided on the shutter base plate 1 as described above. A rotatable roller 21 is attached to the tip back surface of the arm portion 20a provided in the leading blade driving member 20. Further, the leading blade driving pin 20c described above is provided at the tip of another arm portion 20b provided in the leading blade driving member 20.

  Reference numeral 22 denotes a leading blade drive spring, which is a torsion spring attached around the shaft 1d. One end of the leading blade driving spring 22 is supported by a leading blade speed adjusting member (not shown), and the other end is hooked on a protrusion 20 e of the leading blade driving member 20. Thereby, the leading blade driving spring 22 gives the leading blade driving member 20 a rotational force (driving force) in the clockwise direction around the shaft 1d.

  An armature holding portion 20d is formed on the upper portion of the arm portion 20b of the leading blade driving member 20. An armature shaft 24 is attached to the armature holding portion 20d, and an armature (iron piece) 23 is attached to the armature shaft 24 in a state in which a certain amount of movement is allowed in the axial direction of the armature shaft 24. .

  Reference numeral 25 denotes an armature spring, and a compression coil spring is used. The armature spring 25 is disposed in a compressed state between the armature 23 and the armature holding portion 20d around the armature shaft 24. The armature spring 25 has a function of stabilizing the posture of the armature 23 immediately before the armature 23 comes into contact with a yoke described later. The armature spring 25 also has an effect of allowing the leading blade driving member 20 to rotate to the overcharge position after the armature 23 comes into contact with the yoke (absorbing the rotation stroke).

  Reference numerals 26 and 27 denote a yoke and a coil constituting a front curtain electromagnetic magnet, which are fixed to a magnet base plate (not shown). By energizing the coil 27, the armature 23 can be attracted to the yoke 26, and by deenergizing the coil 27, the armature 23 can be desorbed by the yoke 26.

  The rear blade drive member 29 is rotatably attached to the shaft 1e provided on the shutter base plate 1 as described above. A rotatable roller 30 is attached to the back surface of the arm portion 29 a provided in the trailing blade driving member 29. Further, the above-described rear blade drive pin 29c (see FIG. 3) is provided at the tip of another arm portion 29b provided in the rear blade drive member 29.

  Reference numeral 31 denotes a rear blade drive spring, which is a torsion spring attached around the shaft 1e. One end of the trailing blade driving spring 31 is supported by a trailing curtain speed adjusting member (not shown), and the other end is hooked on a protrusion 29 e of the trailing blade driving member 29. As a result, the rear blade drive spring 31 gives the rear blade drive member 29 a rotational force (drive force) in the clockwise direction around the shaft 1e.

  In addition, an armature holding portion 29 d is formed on the upper portion of the arm portion 29 a of the trailing blade driving member 29. An armature shaft 33 is attached to the armature holding portion 29d, and an armature (iron piece) 32 is attached to the armature shaft 33 in a state in which a certain amount of movement is allowed in the axial direction of the armature shaft 33. .

  Reference numeral 34 denotes an armature spring, which uses a compression coil spring. The armature spring 34 is disposed in a compressed state between the armature 32 and the armature holding portion 29d around the armature shaft 33. The armature spring 34 has a function of stabilizing the posture of the armature 32 immediately before the armature 32 comes into contact with a yoke described later. The armature spring 34 also has an action of allowing the rear blade drive member 29 to rotate to the overcharge position (absorbing the rotation stroke) after the armature 32 contacts the yoke.

  Reference numerals 35 and 36 denote a yoke and a coil constituting a rear curtain electromagnetic magnet, which are fixed to a magnet base plate (not shown). By energizing the coil 36, the armature 32 can be attracted to the yoke 35, and by deenergizing the coil 36, the armature 32 can be desorbed by the yoke 35.

  By controlling the energization / energization stop timings for the coils 27 and 36 of the front curtain and rear curtain electromagnetic magnets, the shutter speed can be accurately controlled.

  Reference numeral 37 denotes a leading blade braking member, which is made of a leaf spring material. The leading blade braking member 37 includes a deceleration arm portion (deceleration portion) 37a and a holding arm portion (movement blocking portion) 37b. Each arm portion is attached to a shaft 1i provided on the shutter base plate 1 so as to be rotatable independently.

  The speed reduction arm portion 37 a includes a pressing portion 37 c that is pressed against the side surface of the arm portion 20 a of the leading blade driving member 20, and a tip portion 37 d that can contact the leading blade output arm portion 18 c of the charge lever 18. The rotation of the deceleration arm portion 37a in the clockwise direction is prevented by a seat (not shown) provided near the shutter base plate surface of the shaft 1d.

  The holding arm portion 37 b can be engaged with a locking projection 20 f provided on the back surface of the armature holding portion 20 d of the leading blade driving member 20. At the tip of the holding arm portion 37b, a locking portion 37e for preventing the clockwise rotation around the axis 1d of the leading blade driving member 20 is provided.

  Reference numeral 38 denotes a reduction spring that applies a rotational force in the clockwise direction around the axis 1i to the reduction arm portion 37a of the leading blade braking member 37, and is attached around the axis 1i. The speed reduction spring 38 has a movable arm portion 38 a hung on the speed reduction arm portion 37 a and a fixed arm portion 38 b hung on a spring hook portion 1 j provided on the shutter base plate 1.

  Reference numeral 39 denotes a holding / decelerating spring (see FIGS. 2 and 3), which rotates clockwise around the shaft 1i to the holding arm portion 37b of the leading blade braking member 37 via the first movable arm portion 39a. Give power. The holding / decelerating spring 39 is attached around a shaft 1 h provided on the shutter base plate 1.

  Reference numeral 1k denotes a stopper provided on the shutter base plate 1, which rotates the holding arm portion 37b in the clockwise direction around the axis 1i so that the output arm portion 42b of the leading blade holding release member 42, which will be described later, is in contact therewith. Stop through.

  Reference numeral 40 denotes a rear blade braking member, which is made of a leaf spring material. The trailing blade braking member 40 has a speed reduction arm portion (speed reduction portion) 40a and a holding arm portion (movement blocking portion) 40b. Each arm portion is attached to a shaft 11 provided on the shutter base plate 1 so as to be independently rotatable.

  The decelerating arm portion 40a includes a pressing portion 40c that is pressed against the side surface of the arm portion 29b of the trailing blade driving member 29, and a standing bent portion 40d that can come into contact with the protruding portion 18i provided on the back surface of the charge lever 18 (FIG. 3). Reference).

  The holding arm portion 40 b can be engaged with a locking projection 29 f provided on the back surface of the armature holding portion 29 d of the trailing blade driving member 29. At the front end of the holding arm portion 40b, a locking portion 40e for preventing the clockwise rotation around the axis 1e of the rear blade driving member 29 is provided.

  Reference numeral 41 denotes a holding spring, which applies a turning force in the clockwise direction around the axis 11 to the holding arm portion 40b of the trailing blade braking member 40 through the movable arm portion 41a. The holding spring 41 is attached around the shaft 11, and its fixed arm portion 41 b is hung on a spring hook portion 1 m provided on the shutter base plate 1.

  The second movable arm portion 39b of the holding / decelerating spring 39 described above gives a rotational force in the clockwise direction around the axis 11 to the deceleration arm portion 40a. The spring hooking portion 1m described above also functions as a stopper that prevents the deceleration arm portion 40a in contact with the spring hooking portion 1m from rotating in the clockwise direction.

  Reference numeral 1n denotes a stopper provided on the shutter base plate 1, and prevents the holding arm portion 40b in contact with the stopper from rotating clockwise around the axis 1l.

  The leading blade holding / releasing member 42 has an input arm portion 42a and an output arm portion 42b, and is rotatably attached to a shaft 1p provided on the shutter base plate 1.

  When the charge lever 18 is rotated from the initial position and the blade driving members 20 and 29 are rotated to the overcharge position and then returned to the initial position, the charge lever 18 is provided on the back surface of the charge lever 18 in the vicinity of the initial position. The projected part 18j (see FIG. 5) contacts the input arm part 42a. As a result, the input arm portion 42 a is pushed against the biasing force of the holding / decelerating spring 39. As a result, the leading blade holding release member 42 rotates clockwise around the axis 1p. The output arm portion 42b rotates the holding arm portion 37b of the leading blade braking member 37 counterclockwise around the axis 1i. At the same time, the protrusion 18k provided on the back end of the input arm 18a of the charge lever 18 contacts the holding arm 40b of the rear blade braking member 40 and resists the urging force of the holding spring 41. The part 40b is rotated counterclockwise around the axis 1l.

  The locking portion 37e of the leading blade braking member 37 and the locking portion 40e of the trailing blade braking member 40 are respectively from the rotation regions of the locking projection 20f of the leading blade driving member 20 and the locking projection 29f of the trailing blade driving member 29. evacuate.

  Next, the operation of the shutter 113 configured as described above will be described.

  In the state where the travel of the shutter blades 2 to 5 and 10 to 13 is completed, the shutter blades 2 to 5 for the front curtain close the shutter opening 1a, and the shutter blades 10 to 13 for the rear curtain open the shutter opening 1a. The charge lever 18 is located at an initial position where a counterclockwise rotation around the shaft 1h is prevented by a stopper (not shown).

  From this state, when the driving force F1 from a motor (not shown) is input to the input pin 18b provided on the input arm portion 18a, the charge lever 18 rotates clockwise around the shaft 1h, that is, over. The set operation up to the charge position (charge operation) is started.

  When the charge lever 18 starts rotating, the first cam portion 18e provided in the leading blade output arm portion 18c is moved through the roller 21 attached to the tip of the arm portion 20a of the leading blade driving member 20. The drive member 20 is rotated counterclockwise around the axis 1d. At the same time, the first cam portion 18f provided on the trailing blade output arm portion 18d moves the trailing blade driving member 29 via the roller 30 attached to the tip of the arm portion 29a of the trailing blade driving member 29. It is rotated counterclockwise around the axis 1e.

  FIG. 2 shows a state in which the rollers 21 and 30 are on the curved surfaces connected to the second cam portions 18g and 18h from the first cam portions 18e and 18f in the leading blade and trailing blade output arm portions 18c and 18d. Show. In other words, the state in which the both blade driving members 20 and 29 are moving from the state driven by the first cam portions 18e and 18f to the state driven by the second cam portions 18g and 18h is shown. In this state, the armatures 23 and 32 are not in contact with the yokes 26 and 35.

  After the transition, before the armature 23 contacts the yoke 26, the following operation is performed. On the side surface of the arm portion 20a of the leading blade driving member 20 that has been vigorously rotated counterclockwise until the transition, the pressing portion 37c provided on the deceleration arm portion 37a of the leading blade braking member 37 has its spring force. Is pressed by. As a result, the rotational speed (moving speed) of the leading blade driving member 20 in the counterclockwise direction decreases. That is, the speed reduction arm portion 37 a that is a speed reduction portion acts on the leading blade driving member 20.

  In the present embodiment, the leading blade drive member 20 moves from the state driven by the first cam portion 18e to the state driven by the second cam portion 18g while the speed reducing arm portion 37a (pressing portion 37c). The case of receiving the deceleration action by the will be described. However, the second cam portion 18g further rotates the leading blade driving member 20 in the counterclockwise direction, and the leading blade driving member 20 decelerates after shifting to the state driven by the second cam portion 18g. You may make it receive an effect | action. The same applies to the trailing blade driving member 29 described later.

  Also, before the armature comes into contact with the yoke, the overcharge operation is at least between half of the range of movement from the position after the shutter travels of the armature to the position where it comes into contact with the yoke until it comes into contact. Is preferable from the viewpoint of performing at a high speed.

  On the other hand, the locking protrusion 20f provided on the back surface of the armature holding portion 20d of the leading blade driving member 20 is provided on the holding arm portion 37b of the leading blade braking member 37 to which the urging force is applied from the holding / deceleration spring 39. The latching portion 37e is pushed against the biasing force. This also causes the leading blade driving member 20 to receive a deceleration action.

  By these deceleration operations, the rotation of the leading blade driving member 20 is sufficiently decelerated, and the armature 23 contacts the yoke 26 at a sufficiently low speed (see FIG. 3).

  Also, the trailing blade driving member 29 is similarly decelerated after the transition. That is, on the side surface of the arm portion 29b of the trailing blade driving member 29 that has been vigorously rotated counterclockwise until the transition, the pressing portion 40c provided on the deceleration arm portion 40a of the trailing blade braking member 40 It is pressed by the spring force. As a result, the rotational speed (moving speed) of the rear blade drive member 29 in the counterclockwise direction decreases. That is, the deceleration arm portion 40 a that is a deceleration portion acts on the trailing blade drive member 29.

  On the other hand, the locking projection 20f provided on the back surface of the armature holding portion 29d of the rear blade drive member 29 is an engagement provided on the holding arm portion 40b of the rear blade braking member 40 to which the urging force is applied from the holding spring 41. The stop 40e is pushed against the urging force. This also causes the trailing blade drive member 29 to receive a deceleration action.

  By these decelerating actions, the rotation of the trailing blade drive member 29 is sufficiently decelerated, and the armature 32 contacts the yoke 35 at a sufficiently low speed (see FIG. 3).

  As described above, the suction surfaces of the armatures 23 and 33 and the yokes 26 and 35 are brought into contact with the yokes 26 and 35 in a state where the speed of the armatures 23 and 33 is sufficiently reduced, while the set operation is performed at a high speed. Can be avoided. Therefore, it is possible to maintain high control accuracy during the shutter speed. Further, it is possible to reduce the sound generated when the armatures 23 and 33, which are metal members, and the yokes 26 and 35 abut.

  As shown in FIG. 3, when the setting operation proceeds to a position where the armature 23 and the yoke 26 come into contact with each other (substantially the same position as the drive preparation position), the locking protrusion 20 f of the leading blade driving member 20 moves to the leading blade braking member 37. Get over the locking portion 37e completely. The locking portion 37e is held in the rotation region of the locking projection 20f when the leading blade root braking member 37 receives the urging force of the holding / deceleration spring 39, and can be engaged with the locking projection 20f.

  Further, immediately before the armature 23 and the yoke 26 come into contact with each other (after receiving sufficient deceleration), the front blade output arm portion 18c of the charge lever 18 contacts the front end portion 37d of the front blade braking member 37 while rotating. Press this. As a result, the deceleration arm portion 37 a of the leading blade braking member 37 is pushed back to a position where the pressing portion 37 c is separated from the side surface of the arm portion 20 a of the leading blade driving member 20. That is, the speed reduction arm portion 37 a shifts to a state where it does not act on the leading blade driving member 20. As a result, when the armature 23 and the yoke 26 come into contact with each other, no extra force is applied to the armature 23 and the yoke 26, and the contact surface (suction surface) between the armature 23 and the yoke 26 does not twist. Therefore, it is possible to avoid the adsorption surface from becoming rough due to the twist.

  On the other hand, when the setting operation proceeds to the position where the armature 32 and the yoke 35 come into contact with each other similarly on the rear blade driving member 29 side, the locking protrusion 29f of the rear blade driving member 29 becomes the locking portion of the rear blade braking member 40. Get over 40e completely. The locking portion 40e is held in the rotation region of the locking projection 40f when the trailing blade braking member 40 receives the biasing force of the holding / deceleration spring 39, and can be engaged with the locking projection 40f.

  Immediately before the armature 32 and the yoke 35 come into contact (after receiving a sufficient deceleration action), the protrusion 18 i provided on the back surface of the rotating charge lever 18 is formed on the standing bent portion 40 d of the rear blade braking member 40. Abut. Thereby, the deceleration arm portion 40 a of the rear blade braking member 40 is pushed back to a position where the pressing portion 40 c is separated from the side surface of the arm portion 29 b of the rear blade driving member 29. That is, the deceleration arm portion 40 a shifts to a state where it does not act on the trailing blade drive member 29. As a result, when the armature 32 and the yoke 35 come into contact with each other, no extra force is applied to the armature 32 and the yoke 35, and the contact surface (suction surface) between the armature 32 and the yoke 35 is not twisted. Therefore, it is possible to avoid the adsorption surface from becoming rough due to the twisting.

  FIG. 3 shows an overcharge state reached through the above operation. As described above, the armature springs 25 and 34 are compressed to absorb the rotation stroke of the blade driving members 20 and 29 in the overcharge operation.

  From this state, when the camera release signal is generated and the imaging sequence starts, the coils 27 and 36 of the front curtain and rear curtain electromagnetic magnets are energized at a predetermined timing. As a result, the yokes 26 and 35 of the front and rear curtain electromagnetic magnets attract the armatures 23 and 32.

  When the main mirror 111 and the sub mirror 122 shown in FIG. 1 are retracted out of the imaging optical path, the charge lever 18 linked to the movement of the main mirror 111 is counterclockwise around the axis 1h from the overcharge position (set position). To turn.

  FIG. 4 shows a state where the charge lever 18 and the blade driving members 20 and 29 are moving from the overcharge position to the drive preparation position.

  When the charge lever 18 receives a driving force F2 from a motor (not shown) on the input pin 18b and rotates counterclockwise around the shaft 1h, the pressing portion 37c of the deceleration arm portion 37a of the leading blade braking member 37 is again The side surface of the arm portion 20a of the leading blade driving member 20 is pressed. This pressing force (biasing force) works to assist the rotation of the leading blade driving member 20 in the blade driving direction (clockwise direction around the shaft 1d).

  Further, the leading blade driving member 20 is slightly rotated in the clockwise direction in a state where the suction of the yoke 26 and the armature 23 is maintained. At this time, the locking portion 37e of the leading blade braking member 37 enters a position that forms a slight gap with respect to the locking projection 20f in the rotation region of the locking projection 20f of the leading blade driving member 20. For this reason, even if the armature 23 is not attracted by the yoke 26 due to an impact or the like, the locking projection 20f slightly moves and engages the locking portion 37e, so that the leading blade driving member 20 exceeds the driving preparation position. Rotation in the blade drive direction is prevented. That is, the holding arm portion 37 b that is a movement blocking portion acts on the leading blade driving member 20. Further, since the gap generated between the yoke 26 and the armature 23 is also small at this time, the armature 23 is again attracted to the yoke 26 by the magnetic force generated in the energizing front curtain electromagnetic magnet.

  On the other hand, similarly on the rear curtain side, the pressing portion 40c of the deceleration arm portion 40a of the rear blade braking member 40 presses the side surface of the arm portion 29b of the rear blade driving member 29 again. This pressing force (biasing force) works to assist the rotation of the trailing blade driving member 29 in the blade driving direction (clockwise direction around the shaft 1e).

  Further, the rear blade drive member 29 slightly rotates in the clockwise direction in a state where the suction of the yoke 35 and the armature 32 is maintained. At this time, the locking portion 40e of the trailing blade braking member 40 enters a position where a slight gap is formed with respect to the locking projection 29f in the rotation region of the locking projection 29f of the trailing blade driving member 29. For this reason, even if the armature 32 is not attracted by the yoke 35 due to an impact or the like, the locking projection 29f slightly moves and engages with the locking portion 40e, so that the trailing blade driving member 29 exceeds the driving preparation position. Rotation in the blade drive direction is prevented. That is, the holding arm portion 40 b that is a movement blocking portion acts on the trailing blade driving member 29. Further, since the gap generated between the yoke 35 and the armature 32 is also small at this time, the armature 32 is again attracted to the yoke 35 by the magnetic force generated in the energizing rear curtain electromagnetic magnet.

  In this way, the blade drive members 20 and 29 reach the drive preparation position shown in FIG. The charge lever 18 receives the driving force F2 from the input pin 18b, rotates counterclockwise around the shaft 1h, and returns to the initial position, whereby the shutter 113 is ready for exposure.

  Immediately before the initial position of the charge lever 18 during the return operation to the initial position, the protrusion 18j provided on the back surface of the charge lever 18 contacts the input arm portion 42a of the leading blade holding release member 42. Press. The protrusion 18j rotates the leading blade holding release member 42 clockwise around the axis 1p against the urging force of the holding / decelerating spring 39. Thereby, the output arm part 42b of the leading blade holding release member 42 rotates the holding arm part 37b of the leading blade braking member 37 counterclockwise around the axis 1i. That is, the holding arm portion 37 b is shifted to a state where it does not act on the leading blade driving member 20.

  At the same time, the projection 18k provided on the back surface of the front end of the input arm portion 18a of the charge lever 18 comes into contact with and presses the holding arm portion 40b of the rear blade braking member 40. The protrusion 18k rotates the holding arm 40b counterclockwise around the axis 1l against the urging force of the holding spring 41. That is, the holding arm portion 40 b is shifted to a state where it does not act on the trailing blade driving member 29.

  The locking portion 37e of the leading blade braking member 37 and the locking portion 40e of the trailing blade braking member 40 are respectively from the rotation regions of the locking projection 20f of the leading blade driving member 20 and the locking projection 29f of the trailing blade driving member 20. evacuate. During the retraction, the locking portions 37e and 40e are configured not to contact the locking protrusions 20f and 29f, respectively.

  In this embodiment, the engaging portions 37e and 40e are engaged with the engaging protrusions 20f and 29f with a slight gap until the blade driving members 20 and 29 are moved from the overcharge position to the driving preparation position. The case where it is arranged at a possible position has been described. However, you may make it contact | abut (engage) without leaving a clearance gap between these. In this case, the locking portions 37e and 40e are locking protrusions so that the blade driving members 20 and 29 are not rotated in the opposite direction against the biasing force acting in the blade driving direction (no lift is generated). It is necessary to configure so that 20f and 29f can easily escape.

  When the shutter 113 is ready for exposure, first, the energization of the coil 27 of the front curtain electromagnetic magnet is stopped, and the adsorption of the armature 23 by the yoke 26 is released. As a result, the leading blade driving member 20 is rotated in the clockwise direction by the biasing force of the leading blade driving spring 22 and the auxiliary biasing force from the deceleration arm portion 37a of the leading blade braking member 37. The main arm and the slave arm are rotated in the same direction. The auxiliary biasing force from the deceleration arm portion 37a reduces the biasing force necessary for the leading blade drive spring 22.

  Accordingly, the shutter blades 2 to 5 for the front curtain travel from the position for closing the shutter opening 1a to the position for opening the shutter opening 1a while maintaining a posture parallel to the long side of the shutter opening 1a by the action of the parallel link. .

  When a predetermined shutter speed elapses after the front curtain shutter blades 2 to 5 start running, the energization of the coil 36 of the rear curtain electromagnetic magnet is stopped, and the armature 32 attracted by the yoke 35 is released. As a result, the trailing blade driving member 29 is rotated in the clockwise direction by the biasing force of the trailing blade driving spring 31 and the auxiliary biasing force from the deceleration arm portion 40a of the trailing blade braking member 40. The main arm and the slave arm are rotated in the same direction. The auxiliary biasing force from the deceleration arm portion 40a reduces the biasing force necessary for the trailing blade drive spring 31.

  Accordingly, the shutter blades 10 to 13 for the rear curtain travel from the position where the shutter opening 1a is opened to the position where the shutter opening 1a is closed while maintaining a posture parallel to the long side of the shutter opening 1a by the action of the parallel link. .

  The timing of stopping energization of the coils of the electromagnetic magnets, that is, the travel start timing of the front curtain shutter blades 2 to 5 and the travel start timing of the rear curtain shutter blades 10 to 13 are accurately controlled, so Exposure is performed. Thus, the exposure operation of the shutter 113 is completed. Then, in preparation for the next exposure operation, the setting operation to the overcharge position is started again.

  The embodiments described above are merely representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

1 is a schematic diagram illustrating a configuration of a digital single-lens reflex camera that is an embodiment of the present invention. The figure which shows the state in the middle of the setting operation | movement in the shutter mounted in the camera of an Example. The figure which shows the state which the blade | wing drive member reached | attained the overcharge position in the said shutter. The figure which shows the state in the middle of the blade drive member moving to the drive preparation position from an overcharge position in the said shutter. The figure which shows the state which the blade | wing drive member reached | attained the drive preparation position in the said shutter.

Explanation of symbols

1 Shutter board (shutter base plate)
1a Shutter opening 2-5 Shutter blade for front curtain 10-13 Shutter blade for rear curtain 18 Charging member 18e, 18f First cam portion 18g, 18h Second cam portion 23, 32 Armature 20, 29 Blade driving member 26, 35 Yoke 27, 36 Coil 37, 40 Braking member

Claims (7)

Shutter blades;
A blade driving member including an armature and driving the shutter blade;
The armature is attracted by energization to hold the blade drive member at the drive preparation position, and the attraction is released by energization stop to start driving the shutter blade by the blade drive member from the drive preparation position. Magnets,
A set member that performs a set operation of moving the blade driving member that has driven the shutter blades to a set position beyond the drive preparation position;
After the from the middle of the set operation armature has reduced the moving speed of the blade driving member in contact with said blade drive member before contact with the said electromagnet, said just before the armature abuts the electromagnet a deceleration portion you release the contact between the blade driving member, said driving of said blade driving member until said blade drive member in a state in which the electromagnet is energized to move the drive preparation position from the set position shutter device characterized in that it comprises a braking member which movement preventing portion for preventing movement of the blade drive direction more than ready position are formed, a. The set member includes a first region in which the blade driving member is moved by a first movement amount with respect to the unit movement amount, and the first movement amount of the blade driving member with respect to the unit movement amount. A second region to be moved with a second movement amount smaller than the second region ,
The speed reducer is configured so that the armature moves from the state in which the set member moves the blade driving member in the first region to the state in which the blade driving member moves in the second region. the shutter device according to claim 1 that you contact with the blade driving member before contacting characterized. The reduction unit, said blade drive member in a state in which the electromagnet is energized in contact with the blade driving member until moved to the drive preparation position from the set position, the blades drive the blade driving member the shutter device according to claim 1 or 2, characterized in that to assist the movement in the direction. When said deceleration portion is in contact with said blade driving member, that the setting member moves the brake member, claims 1, characterized that you release the contact between the blade driving member and the reduction gear unit 4. The shutter device according to any one of 3 above. The movement preventing part, after the blade drive member is moved to the drive preparation position, the shutter according to any one of claims 1 to 4, wherein that you save the moving area of said blade driving member apparatus. The said movement prevention part contacts the said blade drive member and reduces the moving speed of the said blade drive member before the said armature contact | abuts to the said electromagnetic magnet from the middle of the said setting operation | movement. 6. The shutter device according to any one of 5 above . An imaging device comprising the shutter device according to claim 1.