JP2017067906A - Focal plane shutter for imaging device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focal plane shutter that can surely prevent bound of a blade caused by impact when an exposure action ends, and can prevent the blade from returning.SOLUTION: Since a third pressing part 11g of a first driving member continues pressing a third pressed part 15g of a locking lever 15 until a permanent magnet 15b fully contacts with an iron core 16a, the locking lever 15 can be surely prevented from bounding and locking of a first locked part 11c of the first driving member by a first locking part 15a of the locking lever 15 can be prevented more surely. This can further ensure reduction of imaging cycles and increase in the speed of continuous shooting without being affected by the usage situation of the imaging device.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a focal pre-shutter for an image pickup apparatus and an image pickup apparatus using both a shutter having blades for opening and closing an opening for a subject optical path and an electronic shutter of an image pickup element.

  Conventionally, as this type of related technology, a focal plane shutter has been proposed that can suppress the bounce of a blade caused by an impact at the end of the exposure operation and prevent the return of the blade, such as the one described in Patent Document 1. In this focal plane shutter, as shown in FIGS. 6 and 7, the collision portion 11 g of the first drive member 11 contacts the collision target portion 15 g of the locking lever 15 at the end of the exposure operation. Thereby, the locking lever 15 is rotated counterclockwise, and is forcibly returned to the position where the first locked portion 11c is locked. At this time, the permanent magnet 15 b of the locking lever 15 is attracted to the iron core member 16 a of the locking lever electromagnet 16 and biases the locking lever 15 counterclockwise. As a result, the first drive member 11 can prevent a bounce caused by an impact that cannot be absorbed by the buffer member 3 when it contacts the lower end of the long hole 1b, and the blades that adversely affect the exposure can be prevented. The return can be prevented.

  However, as in Patent Document 1, when the collision portion 11g of the first drive member 11 comes into contact with the collision target portion 15g of the locking lever 15 and the locking lever 15 is rotated counterclockwise, Although the permanent magnet 15b of the lever 15 is attracted to the iron core 16a of the locking lever electromagnet 16, depending on the use environment of the imaging device such as a digital camera, the bounce that occurs when the permanent magnet 15b and the iron core 16a come into contact with each other. Further, due to the biasing force of the set spring 5 that rotates the blades in the opening direction, the locking lever 15 bounces and rotates in the clockwise direction without being attracted to both, and the locking lever 15 causes the first drive member 11 to rotate. There is a possibility that it cannot be locked. For this reason, there is a possibility that the shooting time lag and the continuous shooting speed become unstable.

JP2015-94936A

  The present invention has been made in view of the above-described conventional circumstances, and the subject of the present invention is that the shooting time lag is further prevented by more reliably preventing the bounce of the blades that adversely affect the exposure at the end of the exposure operation. It is another object of the present invention to provide a focal plane shutter for an imaging apparatus and an imaging apparatus capable of increasing the frame rate in continuous shooting.

  In order to achieve the above object, a focal plane shutter for an imaging device according to the present invention includes a ground plane having an opening for a subject optical path, an arm rotatable with respect to the ground plane, and a blade member connected to the arm. A blade, a first drive member coupled to the blade and having a pushing portion, a second drive member that is urged in the exposure operation direction by the drive spring and that can operate integrally with the first drive member, A locking lever having a driven part and a permanent magnet that are pushed by the pushing part of the first drive member, and an electromagnet having an iron core that can come into contact with the permanent magnet, the first drive member being a second When operating integrally with the drive member, the push portion of the first drive member pushes the pushed portion of the lock lever until the permanent magnet of the lock lever contacts the iron core of the electromagnet. It is characterized by.

  In the focal plane shutter for an image pickup apparatus according to the present invention, a locking portion is formed on the locking lever, a locked portion is formed on the first drive member, and a permanent magnet of the locking lever is formed. It is preferable that the locked portion of the first drive member is locked to the locking portion of the locking lever when it comes into contact with the iron core of the electromagnet.

  In the focal plane shutter for an imaging apparatus according to the present invention, it is preferable that the engagement of the locking lever with the first drive member is released by the repulsion with respect to the permanent magnet due to the energization of the electromagnet.

  Furthermore, an imaging apparatus of the present invention includes the above-described focal plane shutter for an imaging apparatus.

  According to the focal plane shutter for an imaging device and the imaging device of the present invention, the pushing portion of the first drive member pushes the pushed portion of the locking lever until the permanent magnet completely contacts the iron core of the electromagnet. Since it continues to move, the bounce of the locking lever when the permanent magnet comes into contact with the iron core is reliably suppressed, and the locked portion of the first drive member can be locked by the locking portion of the locking lever. This can be done more reliably. As a result, the shooting cycle can be shortened and the continuous shooting frame speed can be increased more reliably without being affected by the use status of the imaging apparatus.

It is the top view which showed the external appearance in the focal plane shutter for imaging devices concerning the Example of this invention. It is a top view which shows the state after completion of setting operation | movement in the focal plane shutter for imaging devices of a present Example. 2A and 2B are diagrams illustrating a configuration of a set drive mechanism unit that drives a set member in a focal plane shutter for an imaging apparatus according to the present exemplary embodiment, where FIG. 3A is a plan view viewed from the ground plane side, and FIG. is there. FIG. 3 is a plan view showing a state immediately before an exposure operation after pressing a release button from the state of FIG. 2. FIG. 5 is a plan view showing a state in the middle of performing an exposure operation after the state of FIG. 4. FIG. 6 is a plan view showing a state in which the first drive member is in contact with the locking lever after the state of FIG. 5. It is a top view which shows the state by which the permanent magnet of the latching lever was made to contact | abut to the iron core after the state of FIG. FIG. 8 is a plan view showing a state in which the exposure operation is completed after the state of FIG. 7 and the first drive member is locked to the locking lever. It is a top view which shows the state in the middle of performing the setting operation | movement after the state of FIG. FIG. 10 is a plan view showing a state in which the setting operation has proceeded after the state of FIG. 9 and the first drive member has been released from being locked by the locking lever. FIG. 11 is a plan view showing a state in which the setting operation further proceeds after the state of FIG. 10 and the first drive member is locked to the locking lever. 6 is a timing chart showing a series of operation sequences from a completion state of blade setting operation to a release, exposure operation, and setting operation in the focal plane shutter for an imaging apparatus of the present embodiment.

  Embodiments of the present invention will be described with reference to the illustrated examples. In the present embodiment, the present invention is applied to the configuration of a direct type focal plane shutter, but it can also be applied to a configuration configured as a locking type.

  First, the configuration of the embodiment of the present invention will be mainly described with reference to FIGS. 1 to 3. FIG. 1 is a plan view of the appearance of the focal plane shutter for an image pickup apparatus of the present embodiment as viewed from the ground plane side. FIG. 2 is a plan view showing a state after completion of the blade setting operation in the focal plane shutter for the image pickup apparatus of the present embodiment, and FIG. 3 is a set drive for driving the set member in the focal plane shutter for the image pickup apparatus of the present embodiment. It is a figure which shows the structure of a mechanism part, (a) is the top view seen from the baseplate side, (b) is a side view of (a). In the description of this embodiment, when the focal plane shutter of this embodiment is incorporated in an imaging apparatus, the front side (front side) in FIGS. 1 and 2 is the subject side (photographing lens side). In the following description, it is assumed that the back side is the image sensor side. However, as is well known, in the case of a digital camera, it does not prevent the front side in FIGS. 1 and 2 from being the image sensor side and the back side in FIGS. 1 and 2 from being the subject side. In the description of the embodiments of the present invention, the front blade is an electronic shutter of the image sensor, and the rear blade is driven by a mechanical drive member to open and close the opening.

  In FIG. 1, the base plate 1 is formed with an opening 1a for a subject optical path. As is well known, an auxiliary base plate 2 is attached to the back side of the base plate 1 at a predetermined interval, and a blade chamber is formed between the base plate 1 and the auxiliary base plate 2. The auxiliary base plate 2 is also formed with an opening 2a having substantially the same shape and size as the opening 1a. The shape of the opening serving as a shutter unit for allowing the subject light to pass through is formed by a combination of these openings 1a and 2a or a thin-plate opening regulating member provided in addition to the ground plane 1 and the auxiliary ground plane 2. However, in this embodiment, the shape of the opening for the subject optical path is determined by the opening 1a.

  In FIG. 1, a part of the area adjacent to the opening 1 a of the ground plane 1 is shown in a broken view so that a part of the auxiliary ground plane 2 can be seen. 2 and 4 to 11, for convenience, the right side portion of the opening 1a shown in FIG. 1 is omitted.

  As shown in FIG. 2, the base plate 1 is formed with an arc-shaped long hole 1b in a region on the left side of the opening 1a. A well-known rubber cushioning member 3 having a substantially C-shaped planar shape is attached to the lower end of the long hole 1b. In addition, since the auxiliary base plate 2 overlaps with the region where the long hole 1b is formed, actually, a long hole (not shown) having the same shape is formed at the position overlapping the long hole 1b.

  On the surface side of the main plate 1, shafts 1c, 1d, and 1e are erected. Of these, the shaft 1e is shorter than the other shafts 1c and 1d. In addition, shafts 1f and 1g are erected on the back side of the base plate 1, that is, on the imaging element side. Of these, the shaft 1f is erected concentrically with the shaft 1c. Further, a stopper portion 1 i made of a rectangular groove is provided on the surface side of the main plate 1.

  In addition to the above, a plurality of pillars are actually erected on the surface side of the main plate 1, and a support as described in, for example, Japanese Patent Application Laid-Open No. 2007-298544 is provided at the tip of these columns. A board 23 and a printed wiring board are attached with the support board 23 facing the ground plane 1, and the ground plane 1 side of the support board 23 is substantially U-shaped and the tips of the two leg portions are connected to the magnetic pole section. An electromagnet for a blade, which is composed of an iron core member, a coil, and a bobbin wound around the coil and fitted on one leg of the iron core member, is attached. However, since the configuration of the blade electromagnet and the mounting configuration to the support plate are well known, in FIGS. 4 to 11 in addition to FIG. 2, only the iron core member is denoted by reference numeral 4 in FIGS.

  A first drive member 11 and a second drive member 12 constituting a drive mechanism are provided on the shaft 1c erected on the surface side of the base plate 1 so that the first drive member 11 faces the base plate 1. On the side, they are individually mounted for rotation.

  First, the first drive member 11 includes a pushed portion 11a, a drive pin 11b, a first locked portion 11c, a first pushed portion 11f, a second locked portion 11d, and a second pushed portion. It has a moving part 11e and a third pushing part 11g. The driven portion 11 a and the drive pin 11 b are formed so as to overlap on the front surface side and the back surface side, and the drive pin 11 b formed on the back surface side is inserted into the long hole 1 b of the main plate 1. The drive pin 11b has a circular cross section at the root side. Further, the cross section of the tip side portion has a bullet shape, and is connected to the arm 17 in the blade chamber as will be described later, and the most advanced portion is formed in the auxiliary base plate 2 and is the same as the long hole 1b. It is inserted into a long hole (not shown) having a shape. The third pushing portion 11g is provided on the opposite side of the first locked portion 11c across the first pushing portion 11f of the first drive member 11, and a third pushed portion of a locking lever 15 described later. The moving part 15g is formed into a shape that can be pushed.

  On the other hand, the second drive member 12 has a mounting portion 12a formed thick on the subject side, a pushing portion 12c formed on the ground plate 1 side of the mounting portion 12a, and a pushed portion 12b formed on the subject side. Yes. As is well known, the second drive member 12 is urged to rotate clockwise (in the direction of arrow A about the axis 1c in FIG. 2) by the urging force of a drive spring (not shown). However, the pushing portion 12c is a portion that pushes the pushed portion 11a of the first drive member 11 when rotating.

  In the mounting portion 12a of the second drive member 12, an iron piece member 13 and a compression spring (not shown) are housed. The iron piece member 13 has a disk-shaped head portion 13b at one end of the shaft portion 13a, and an iron piece portion 13c is attached to the other end. The iron piece member 13 is urged so as to protrude the iron piece portion 13c from the attachment portion 12a by the compression spring (not shown) fitted to the shaft portion 13a in the attachment portion 12a. In FIG. 2, the iron piece portion 13c comes into contact with the magnetic pole portion of the iron core member 4 of the blade electromagnet, and is pushed into the mounting portion 12a against the biasing force of the compression spring (not shown). Part of which appears, and the head 13b is in a state of being separated from the mounting portion 12a.

  A ratchet member 24 is rotatably attached to the shaft 1c of the main plate 1 as schematically shown in FIG. The ratchet member 24 includes ratchet teeth (not shown) on the outer peripheral portion, and the tip of a ratchet claw (not shown) formed on the support plate 23 is meshed with the ratchet teeth. This prevents rotation in the clockwise direction.

  As is well known, one end of the drive spring is hooked on a spring hooking portion (not shown) of the second drive member 12 and the other end is hooked on a spring hooking portion (not shown) of the ratchet member 24. The urging force can be adjusted by temporarily removing the ratchet member 24 and changing the rotational position of the ratchet member 24.

  A set member 14 is rotatably attached to the shaft 1d provided upright on the surface side of the main plate 1. The set member 14 includes an attachment portion 14a to which a first lever 51a (see FIG. 3) of a link lever 51 of the set drive mechanism portion 50, which will be described later, is rotatably attached, and a driven portion 12b of the second drive member 12. And a pushing portion 14b.

  The set member 14 is urged to rotate counterclockwise (in the direction of arrow B about the axis 1d in FIG. 2) by a return spring (not shown). FIG. 2 will be described later. This shows a state where the set drive mechanism 50 (see FIG. 3) is rotated clockwise against the urging force of the return spring and stopped at the set position. FIG. 4 shows a state in which it is rotated counterclockwise by the urging force of such a return spring and is brought into contact with a stopper (not shown) provided on the shutter base plate 1 and stopped. Yes. Hereinafter, with respect to the set member 14, the position shown in FIG.

  A locking lever 15 is rotatably attached to the shaft 1 e that is erected on the surface side of the main plate 1. The locking lever 15 includes a first locking portion 15a provided at one end of the locking lever 15, a first driven portion 15f, a permanent magnet 15b provided at the other end of the locking lever 15, It has 2 latching | locking parts 15c, the 2nd to-be-driven part 15d, the contact part 15e, and the 3rd to-be-driven part 15g. The locking lever 15 constitutes a locking mechanism in the present invention together with a locking lever electromagnet 16 described later.

  Further, the latch lever 15 is counteracted by the magnetic force attracted to the latch lever electromagnet 16 generated by the permanent magnet 15b when the energization of the latch lever electromagnet 16 is released (that is, the energization is OFF). Energized to rotate in the clockwise direction (the direction of arrow C centering on the axis 1e in FIG. 2), the locking lever electromagnet 16 is energized in the first direction (for example, as shown in FIG. 12, it is energized in the positive direction). In the ON state, the magnet is urged to rotate in the clockwise direction by the magnetic force generated from the permanent magnet 15b and the magnetic force repelling from the locking lever electromagnet 16. In FIG. 2, the energization of the locking lever electromagnet 16 is released, and the locking lever 15 is rotated counterclockwise by the attracting force of the permanent magnet 15b to the locking lever electromagnet 16, and the permanent magnet 15b. Is brought into contact with the locking lever electromagnet 16 to stop the counterclockwise rotation.

  The first locking portion 15a of the locking lever 15 is positioned in a state in which the permanent magnet 15b is in contact with the magnetic pole portion of the iron core member 16a of the locking lever electromagnet 16. By locking the locked portion 11c, the first drive member 11 is formed to be prevented from rotating in the setting direction (counterclockwise direction). The first locking portion 15a travels in the exposure direction of the first drive member 11 when the permanent magnet 15b is positioned in contact with the magnetic pole portion of the iron core member 16a of the locking lever electromagnet 16. It also has a function of suppressing the bounce of blades caused by an impact when the drive pin 11b of the first drive member 11 comes into contact with the buffer member 3 at the lower end of the long hole 1b at the end. The first driven portion 15 f is a first drive member 11 that travels in the exposure direction when the permanent magnet 15 b is positioned in contact with the magnetic pole portion of the iron core portion 16 material a of the locking lever electromagnet 16. The first driving member 11 is configured to be pressed while being slidably contacted with the first pushing portion 11f. The first driving member 11 traveling in the exposure direction is braked by being pressed while being slidably contacted with the first pushing portion 11f. It has a function.

  The second locking portion 15 c is located when the permanent magnet 15 b is separated from the magnetic pole portion of the iron core member 16 a of the locking lever electromagnet 16 and the contact portion 15 e is in contact with the stopper portion 1 i of the base plate 1. In addition, the first drive member 11 is locked to the second locked portion 11d to prevent the first drive member 11 from rotating in the exposure direction (clockwise in FIG. 2). And the 2nd latching | locking part 15c is located in the state which the permanent magnet 15b left | separated from the magnetic pole part of the iron core member 16a of the electromagnet 16 for latching levers, and the contact part 15e contact | abutted to the stopper part 1i of the base plate 1. When the first drive member 11 returns in the set direction, the bounce of the blades caused by the impact when the drive pin 11b of the first drive member 11 comes into contact with the upper end of the long hole 1b is suppressed. It has a function.

  The second driven portion 15 d is located in a state where the permanent magnet 15 b is separated from the magnetic pole portion of the iron core member 16 a of the locking lever electromagnet 16 and the contact portion 15 e is in contact with the stopper portion 1 i of the base plate 1. In some cases, it is configured to be pressed while being in sliding contact with the second pushing portion 11e of the first drive member 11 traveling in the set direction (counterclockwise in FIG. 2). By being pressed while in contact, the first drive member 11 traveling in the set direction is braked.

The contact portion 15e is formed to stop the rotation of the locking lever 15 in the clockwise direction by contacting the stopper portion 1i of the base plate 1.
The third pushed portion 15g is provided between the first locking portion 15a and the second locking portion 15c, and is shaped to be pushed by the third pushing portion 11g of the first drive member 11. Is formed. The third pushed portion 15g of the locking lever 15 and the third pushed portion 11g of the first drive member 11 are the same as the first push portion 11f of the first drive member 11 rotated in the exposure operation direction. With respect to the locking lever 15 rotated in the direction of releasing the locking with the first locked portion 11c of the first drive member 11 by pushing the first driven portion 15f of the locking lever 15 away, When the first drive member 11 reaches the exposure operation end position (that is, the position where it abuts the lower end of the long hole 1b (the buffer member 3 as a stopper provided therein)), the third push of the first drive member 11 The moving portion 11g abuts on the third driven portion 15g of the locking lever 15 and rotates the locking lever 15 in the direction in which the first locked portion 11c of the first drive member 11 is locked. The locking lever 15 is forcibly returned to the position where the locking lever 15 is locked to the first locked portion 11c. It has a function to be.

  The locking lever electromagnet 16 is substantially U-shaped and has an iron core member 16a, a coil 16b, and a coil 16b wound around one leg of the iron core member. And a bobbin 16c fitted to the portion, and attached to the subject side of the main plate 1 so that the magnetic pole portion of the iron core member 16a can come into contact with the permanent magnet 15b of the locking lever 15. When the coil 16b is energized in the first direction, the locking lever electromagnet 16 generates a magnetic force that repels the permanent magnet 15b of the locking lever 15 from the magnetic pole portion of the iron core member 16a. When the energization of the iron core member 16a is released, the magnetic pole portion of the iron core member 16a does not emit magnetic force and is attracted to the magnetic pole portion of the iron core member 16a by the magnetic force of the permanent magnet 15b.

  In addition to this, a set member drive mechanism 50 for driving the set member 14 is provided on the surface side of the main plate 1. As shown in FIGS. 3A and 3B, the set member driving mechanism 50 includes a link lever 51, a slide lever 52, a cam 53, a gear train 54, a housing 55, and a motor 56. doing.

  The link lever 51 includes a first lever 51a and a second lever 51b. One end of the first lever 51a is rotatably attached to the attachment portion 14a of the set member 14, and the other end is rotatably attached to the second lever 51b. The second lever 51b is attached to one end of the second lever 51b so as to be rotatable with respect to the shaft 1x erected on the main plate 1. The second lever 51b is provided with a contact portion 51b-1 that contacts the contact portion 52c of the slide lever 52 at the other end while rotatably attaching the first lever 51a at the center.

The slide lever 52 has a driven portion 52a at one end, a pin 52b between one end and the other end, and a contact portion 52c that contacts the contact portion 51b-1 of the second lever 51b of the link lever 51 at the other end. Each has it. The pushed portion 52 a is provided so as to be pushed by the pushing portion 53 a of the cam 53. The contact part 52 c is provided so as to contact the contact part 51 b-1 of the link lever 51. The pin 52b is provided so as to be guided along a guide hole 55a provided in the housing 55. Although not shown in FIG. 3 for convenience, the inside of the housing 55 is configured to accommodate the slide lever 52 so as to be movable along the direction of the guide hole 55a.

The cam 53 is provided so as to be rotatable coaxially with the gear 54b of the gear train 54 inside the housing 55, and slides within a predetermined rotation angle range (a range of about 180 degrees in the example of FIG. 3B). A pushing portion 53a capable of pushing the pushed portion 52a of the lever 52 is provided. The pushing portion 53a has a first curved surface region 53a-1 formed in an arc shape having a maximum distance from the shaft and a first distance as the distance from the shaft is separated from the first curved surface region 53a-1. The second curved surface region 53a-2 is formed so as to be shorter than the curved surface region 53a-1.
The gear train 54 includes gears 54 a and 54 b that are provided inside the housing 55 and mesh with each other.
The motor 56 includes a pinion 56a on the rotation axis, and is configured to rotate the rotation axis in one direction (in FIG. 3B, clockwise (in the direction of arrow X centered on the axis of the motor 56)). . The pinion 56 a meshes with the gear 54 a of the gear train 54.

  Then, in the set member driving mechanism 50, the motor 56 rotates the rotation axis in the clockwise direction (the arrow X direction centering on the axis of the motor 56 in FIG. 3B), and via the pinion 56a, the gear 54a, and the gear 54b. The cam 53 rotates clockwise (in the direction of arrow Z around the axis of the cam 53 in FIG. 3B), so that the pushing portion 53a of the cam 53 pushes the pushed portion 52a of the slide lever 52. The slide lever 52 moves in the arrow W direction while the pin 52b is guided by the guide hole 55a of the housing 55, and the contact portion 52c pushes the contact portion 51b-1 of the link lever 51, so that the second lever 51b is moved. The first lever 51a rotates counterclockwise (in the direction of arrow V centering on the axis 1x in FIG. 3A) and the first lever 51a counterclockwise against the biasing force of the return spring (not shown). Rotating (opposite direction of the arrow B direction around the axis 1d in FIG. 2). FIG. 3A shows a state in which the setting member 14 is rotated to near the setting completion position.

  When the set member 14 reaches the set position, the pushing portion 53a of the cam 53 has the first curved surface region 53a-1 having the maximum distance from the shaft and the fixed portion 52a of the slide lever 52. The set member 14 is held at the set completion position while the first curved surface region 53a-1 is pushing and the pushed portion 52a of the slide lever 52 is pushed.

  Further, in the set member driving mechanism 50, the motor 56 further rotates the rotation axis clockwise (in the direction of the arrow X about the axis of the motor 56 in FIG. 3B) from the state where the set member 14 has reached the set completion position. The cam 53 is rotated clockwise via the pinion 56a, the gear 54a, and the gear 54b (in the direction of arrow Z around the axis of the cam 53 in FIG. 3B), thereby pushing the cam 53. When 53a moves away from the pushed portion 52a of the slide lever 52, the set member 14 is counterclockwise (in the direction of arrow B centering on the axis 1d in FIG. 2) by the biasing force of the return spring (not shown). Rotate.

  Therefore, the second lever 51b rotates in the clockwise direction (the direction opposite to the arrow V direction centering on the axis 1x in FIG. 3A) via the first lever 51a of the link lever 51, and the contact portion When 51b-1 pushes the contact portion 52a of the slide lever 52, the slide lever 52 moves in the direction opposite to the arrow W direction while the pin 52b is guided by the guide hole 55a of the housing 55. When the pin 52b of the slide lever 52 comes into contact with the lower end of the guide hole 55a of the housing 55 in FIG. 3A, the slide lever 52 stops and the link lever 51 and the set member 14 stop rotating. To do. The stop position of the set member 14 is the above-described initial position.

Next, the configuration on the back side of the main plate 1 will be described.
The blades 23 disposed between the main plate 1 and the auxiliary main plate 2 are provided with an arm 17 having one end rotatably attached to the shaft 1f of the main plate 1 and the shaft 1g of the main plate 1. An arm 18 having one end rotatably attached thereto and four blade members 19, 20, 21, and 22 that are pivotally supported in turn toward the other end that is a free end of the arm 18. Reference numeral 22 denotes a slit forming blade. As described above, the tip of the drive pin 11 b of the first drive member 11 is fitted into a hole (not shown) formed in the arm 17.

  Further, a set spring 5 that is a torsion coil spring is fitted to the shaft 1g of the base plate 1, one end of which is hooked on the spring hooking portion 1h of the base plate 1, and the other end is hooked on the hole 18a of the arm 18, The arm 18 is urged so as to rotate counterclockwise (in the direction of arrow D about the axis 1g in FIG. 2). Therefore, the set spring 5 urges the first drive member 11 to rotate counterclockwise via the blades 23, and the urging force is applied to the second drive member 12. It is weaker than the biasing force of the drive spring (not shown). In the case of the set spring 5, the function of a well-known blade backlash spring (a spring hung on the arm 18 to make the exposure operation start position of the slit forming blade 22 constant) is also used. It may be configured to be hung directly on the driving member 11 or may be configured to be hung between two driving members. For convenience, arrows A to D are shown only in FIG.

  Next, the operation of this embodiment will be described with reference to FIG. 2 used in the above description of the configuration and FIGS. 4 to 12. FIG. 12 is a timing chart showing a series of operation sequences from the completion state of the setting operation of the blade 23 to the pressing of the release button of the imaging device such as a digital camera, the exposure operation, and the setting operation. The timings at which the operation states in FIGS. 4 to 11 are indicated are indicated by numerals in the respective drawings.

  FIG. 2 shows a state after the set operation of the blades 23 is completed as already described. At this time, the second drive member 12 is rotated counterclockwise against the urging force of a known drive spring (not shown) by the clockwise rotation of the set member 14, and the iron piece portion 13 c of the iron piece member 13. Is in contact with the magnetic pole part of the iron core member 4 of the electromagnet for blades. Further, the first drive member 11 is rotated in the counterclockwise direction by the biasing force of the set spring 5, but the drive pin 11 b of the first drive member 11 is a long hole of the auxiliary base plate described above. This stop state is maintained because it is in contact with the upper end of the. At this time, the four blade members 19, 20, 21, and 22 are overlapped and retracted from the opening 1 a. Therefore, for the first drive member 11 and the blade 23, the position obtained in this way is the exposure operation start position.

  Further, the energization of the locking lever electromagnet 16 is released, and the locking lever 15 is attracted to the magnetic pole portion of the iron core member 16a of the locking lever electromagnet 16 which is emitted from the permanent magnet 15b as described above. The permanent magnet 15b is rotated counterclockwise by the magnetic force, and the rotation is stopped by contacting the magnetic pole portion of the iron core member 16a of the locking lever electromagnet 16. At this time, the set member 14 is in the set completion position, and the pushing portion 14 b is in contact with the pushed portion 12 b of the second drive member 12.

  Note that the method of photographing using the front blade electronic shutter in the focal plane shutter of this embodiment is a case of photographing using an electronic viewfinder, but it is movable in the case of an imaging device having a movable mirror (not shown). The mirror is up.

  Further, the set member 14 is maintained in this state by the set drive mechanism 50 (see FIG. 3) against the biasing force of a return spring (not shown) until the next photographing is performed. Accordingly, in this state, the opening 1a is fully open, so that the subject image can be observed with the electronic viewfinder, and further, a moving image can be taken.

Next, a case will be described in which shooting is performed from the set completion state shown in FIG. When the release button of the image pickup apparatus is pressed while observing the subject image with the electronic viewfinder, the electromagnet for the blade is in an excited state before the actual photographing (exposure operation) is started, and the iron piece portion 13c of the iron piece member 13 is made of iron. It is attracted and held by the magnetic pole part of the core member 4.
Next, since the set drive mechanism 50 (see FIG. 3) releases the force that rotates the set member 14 in the clockwise direction via the link lever 51, the set member 14 is caused by the biasing force of the return spring (not shown). It rotates counterclockwise and is returned to the initial position. In the returning operation, the pressing member 14b of the set member 14 moves away from the driven portion 12b of the second driving member 12, so that the second driving member 12 is rotated by a biasing force of a driving spring (not shown). Although the iron piece member 13 is attracted and held by the iron core member 4, the attachment portion 12 a is brought into contact with the head portion 13 b of the iron piece member 13 and stopped. FIG. 4 shows the exposure operation start position of the second drive member 12 thus obtained.

  Thereafter, when the set member 14 returns to the initial position, the leading blade electronic shutter of the image sensor is turned on, and the electronic control circuit controls the image sensor to start capturing a still image. When a predetermined time determined according to the brightness of the subject elapses, the blade electromagnet is demagnetized (OFF in FIG. 12). When the electromagnet for blades is demagnetized, the attractive force of the iron core member 4 with respect to the iron piece member 13 is lost, and the second driving member 12 is rapidly rotated clockwise by the biasing force of the driving spring. Therefore, immediately after the second drive member 12 starts to rotate, the pushing portion 12c of the second drive member 12 and the pushed portion 11a of the first drive member 11 come into contact with each other, and the first drive member 11 starts to be pushed. The first drive member 11 is rotated clockwise against the urging force of the set spring 5, and the four blade members 19 to 22 are moved downward while reducing the overlap between adjacent blades, The opening 1 a is closed at the lower edge of the slit forming blade 22.

  Thereafter, when the first drive member 11 is rotated to the vicinity of the end position of the rotation in the exposure direction, the first pushing portion 11f of the first driving member 11 moves the first pushed portion 15f of the locking lever 15 into place. Pushing while sliding, the locking lever 15 is slightly rotated in the clockwise direction against the attracting force of the permanent magnet 15b against the magnetic pole part of the iron core member 16a. A state in the middle of such an exposure operation is shown in FIG.

  From the state of FIG. 5, the first drive member 11 is further pushed by the second drive member 12 biased by the drive spring and continues to rotate in the clockwise direction. At this time, the first driven portion 15f of the locking lever 15 is pressed while being in sliding contact with the first pressing portion 11f of the first drive member 11, and the locking lever 15 is rotated in the clockwise direction. Thus, the clockwise rotation of the first drive member 11 is braked.

  However, the first drive member 11 further rotates clockwise, and the drive pin 11b comes into contact with the buffer member 3 provided at the lower end of the long hole 1b. Further, the sliding contact of the locking lever 15 with the first pushed portion 15f by the first pushing portion 11f of the first driving member 11 is released, and as shown in FIG. The pushing portion 11 g comes into contact with the third pushed portion 15 g of the locking lever 15. Thereafter, the first driving member 11 further rotates clockwise, and the locking lever 15 is flipped counterclockwise (that is, the direction in which the first locked portion 11c of the first driving member 11 is locked) The first locked portion 11c is forcibly returned to the position where it is locked.

  For this reason, the locking lever 15 is pushed from the position rotated in the direction of releasing the locking of the first driving member 11 with the first locked portion 11c by being pushed by the first driving member 11. The drive pin 11b of the drive member 11 is rotated counterclockwise toward a position where the bounce generated by an impact when the drive pin 11b contacts the buffer member 3 is suppressed. At this time, the first drive member continues to push the locking lever 5 until the permanent magnet 15b reliably contacts and attracts the magnetic pole portion of the iron core member 16a of the locking lever electromagnet 16. Such a state is shown in FIG.

  As a result, the drive pin 11b of the first drive member 11 is used as a buffer member for the return of the first drive member 11 to the lock position of the first locked portion 11c by the first lock portion 15a of the lock lever 15. 3 can be reliably completed and maintained before it bounces upon impact when it abuts 3 and returns to the direction in which the slit forming blade 22 opens the opening 1a. This also reliably prevents the first drive member 11 from bouncing due to an impact that cannot be resolved by the buffer member 3 when the drive pin 11b contacts the lower end of the long hole 1b, and adversely affects exposure. Is prevented from returning (in this embodiment, the opening of the blade from the opening 1a). Then, almost at the same time as the contact of the drive pin 11b of the first drive member 11 with the buffer member 3, the leading blade electronic shutter is turned off. The end state of the exposure operation at that time is shown in FIG.

  In the prior art, the third pushing portion 11g of the drive member 11 abuts on the third pushed portion 15g of the locking lever 15 to rotate the locking lever 15 counterclockwise. Since the state does not continue until the permanent magnet 5b contacts the iron core member 16a, the locking lever 15 is rotated counterclockwise by inertia from the middle. Therefore, depending on the use environment of the imaging device, the locking lever 15 may be bound and rotated clockwise by the impact when the permanent magnet 15b contacts the iron core 16a. At this time, the bounce when the drive pin 1b of the first drive member 11 abuts against the buffer member 3, and the influence of the biasing force of the set spring 5 that biases the first drive member 11 via the arm and the blade member. As a result, the first drive member 11 is rotated counterclockwise and returned, and the first locked portion 11c is rotated to a position beyond the locking position locked by the first locking portion 15a. In some cases, it was not locked.

  However, in this embodiment, as shown in FIG. 7, the third pushing portion 11g of the first driving member is the third pushed portion 15g of the locking lever 15, and the permanent magnet 15b is the iron core 16a. The bounce of the locking lever 15 is reliably suppressed, and the engagement of the first locked portion 11c of the first driving member by the first locking portion 15a of the locking lever 15 is continued. The stopping can be performed more reliably. As a result, the shooting cycle can be shortened and the continuous shooting frame speed can be increased more reliably without being affected by the use status of the imaging apparatus.

  Next, the set operation will be described. In the focal plane shutter of the present embodiment, when the exposure operation by the blades 23 is completed and the state shown in FIG. 8 is reached at the time of shooting with the leading blade electronic shutter method, the imaging information of the still image is immediately transmitted from the imaging device. Although it is transferred to the storage device via the processing circuit, even if the setting member 14 starts the blade setting operation during the transfer of the imaging information, the blade members 19 to 22 remain covered with the opening 1a and serve as the imaging device. Is not exposed to light, and after the imaging information transfer is completed, and before the setting operation of the blade 23 by the setting member 14 is finished, the blade 23 is opened and the opening 1a is fully opened. I am doing so. For this reason, a series of shooting cycles from when the release button of the imaging device is pressed during shooting until shooting is completed and the next shooting standby state is obtained, shortening the shooting cycle and increasing the frame speed of continuous shooting. You can be more certain.

  Furthermore, the focal plane shutter according to the present embodiment is configured such that when the blade 23 is immediately before the end of the setting operation and the urging force of the set spring 5 returns from the closed state of the opening 1a to the fully opened state, The drive pin 11b may come into contact with the upper end portion of the long hole of the auxiliary base plate 2 (not shown) to generate a bounce. For this reason, if this bounce does not fall, the start position of the blade 23 when the exposure operation is performed becomes unstable and causes uneven exposure. Therefore, the exposure operation cannot be performed until the bounce of the blade 23 converges. It was. However, in the focal plane shutter according to the present embodiment, the second locking is performed on the locking lever 15 as a bounce suppressing mechanism that suppresses the bounce when the blade 23 returns to the exposure start position where the opening 1a is fully opened from the closed state. By providing the part 15c, the bounce can be suppressed. This shortens the series of shooting cycles from when the release button of the imaging device is pressed during shooting until shooting is completed and the next shooting standby state is obtained, shortening the shooting cycle and increasing the frame speed of continuous shooting. It can be done even more reliably.

  Moreover, in the focal plane shutter of the present embodiment, the locking mechanism can be rotated around the axis, and the first locked portion 11c provided on the first drive member 11 is locked at one end. The first driving member 11 has a first locking portion 15a for preventing rotation in the set operation direction, and has a locking lever 15 having a permanent magnet 15b at the other end, and the permanent magnet 15b by energization in one side direction. The latching lever electromagnet 16 that generates a repulsive magnetic force is provided, and the latching lever 15 is first driven in response to switching between energization of the latching lever electromagnet 16 only in one direction and cancellation of the energization. Since the first locking portion 11c of the member is rotated by switching between the direction in which the first locking portion 11c is locked and the direction in which the locking is released, the first locking portion 15a is engaged with the first locked portion 11c. When energized, release the power and release the lock. Only by controlling the energization to energize the one side direction, it is possible to reduce power consumption by reducing the conduction time at.

Therefore, in the following, it will be specifically described that the focal plane shutter of the present embodiment can suitably perform such an operation. When the exposure operation is completed and the state of FIG. 8 is obtained, in the case of this embodiment, as described above, the set operation is immediately started. However, the set operation of the blade 23 is performed by the set drive mechanism 50 ( 3) is performed by rotating the set member 14 in the clockwise direction against a biasing force of a return spring (not shown) via the link lever 51.

  When the setting operation of the blade 23 is started, the pushing portion 14b of the setting member 14 pushes the pushed portion 12b of the second driving member 12, and the second driving member 12 is biased by a driving spring (not shown). Rotate counterclockwise against it. At this time, the first driving member 11 is given a force for rotating the blades 23 counterclockwise by the set spring 5, but the first locking portion 15 a of the locking lever 15 is connected to the first driving member 11. By locking the first locked portion 11c, the rotation of the first drive member 11 in the counterclockwise direction is suppressed.

  Thereafter, the set member 14 continues to rotate in the clockwise direction, so that the second drive member 12 is pressed against the biasing force of the drive spring (not shown) by the pushed portion 12b being pushed by the push portion 14b. Although the first driving member 11 is rotated counterclockwise, the first locked portion 11 c is locked to the first locking portion 15 a of the locking lever 15. It cannot be rotated counterclockwise. Therefore, only the second drive member 12 continues to rotate counterclockwise with the four blade members 19 to 22 covering the opening 1a.

  After that, the iron piece portion 13c of the iron piece member 13 attached to the second drive member 12 contacts the magnetic pole portion of the iron core member 4 of the blade electromagnet. The transfer of the imaging information of the still image is over. Thereafter, the set member 14 is slightly rotated and stopped at the set completion position. The state at that time is shown in FIG.

  Further, when the iron piece portion 13c of the iron piece member 13 contacts the magnetic pole portion of the iron core member 4, energization in the positive direction to the coil 16b of the locking lever electromagnet 16 is turned ON, and the magnetic pole portion of the iron core member 16a is turned on. The magnetic force which repels with respect to the permanent magnet 15b of the latching lever 15 is emitted. Thereby, the locking lever 15 rotates clockwise, and the locking of the first driving member 11 to the first locked portion 11c by the first locking portion 15a is released. Further, the locking lever 15 is stopped from rotating in the clockwise direction when the contact portion 15e contacts the stopper portion 1i of the main plate 1.

  The first driving member 11 starts to rotate counterclockwise by the urging force of the set spring 5 when the locking of the locking lever 15 to the first locked portion 11c by the first locking portion 15a is released. . Then, the four blade members 19 to 22 move upward while increasing the overlap between adjacent blades, and open the opening 1a.

  Then, the second pushing portion 11e slides on the second pushed portion 15d of the locking lever 15 while the blade 23 is traveling back in the setting direction with the counterclockwise rotation of the first driving member 11. The latch lever 15 is pressed against the permanent magnet 15b against the repulsive force against the magnetic force generated from the magnetic pole portion of the iron core member 16a when the permanent magnet 15b energizes the coil 16b of the latch lever electromagnet 16 in the positive direction. The stop lever 15 is slightly rotated counterclockwise. FIG. 10 shows a state in the middle of traveling back to the set position of the first drive member 11.

  From the state shown in FIG. 10, the first drive member 11 continues to rotate counterclockwise. At this time, the second driven portion 15d of the locking lever 15 is pressed while being in sliding contact with the second pressing portion 11e of the first drive member 11, and the locking lever 15 is rotated counterclockwise. Thus, the counterclockwise rotation of the first drive member 11 is braked. Thereafter, the first drive member 11 further rotates counterclockwise, and the drive pin 11b comes into contact with the upper end of the long hole of the auxiliary base plate 2 (not shown). At this time, the sliding contact of the locking lever 15 with the second pushed portion 15d by the second pushing portion 11e of the first drive member 11 is released. For this reason, the locking lever 15 is rotated clockwise again by the repulsive force against the magnetic force generated from the magnetic pole part of the iron core member 16a when the permanent magnet 15b is energized in one direction to the coil 16b of the locking lever electromagnet 16. As a result of the rotation, the contact portion 15e comes into contact with the stopper portion 1i, and the second locking portion 15c can lock the second locked portion 11d of the first drive member 11.

  Thereby, the 1st drive member 11 is suppressed from the bounce by the impact when it contact | abuts to the upper end part of the long hole of the auxiliary | assistant ground plane 2. FIG. Thereby, the setting operation of the blade 23 accompanied with the counterclockwise rotation of the first drive member 11 is completed, and the operation of the first drive member 11 and the blade 23 is stopped. The state at that time is shown in FIG.

  After the state of FIG. 11, the energization to the coil 16b of the locking lever electromagnet 16 is released, and no magnetic force repelling the permanent magnet 15b emitted from the magnetic pole portion of the iron core member 16a is generated. Then, the locking lever 15 rotates counterclockwise by the attractive force of the locking lever electromagnet 16 to the magnetic pole portion of the iron core member 16a by the permanent magnet 15b of the locking lever 15, and the second locking portion 15c The locking of the first drive member 11 with respect to the second locked portion 11d is released. The locking lever 15 is stopped from rotating counterclockwise when the permanent magnet 15b is attracted to and abuts against the magnetic pole portion of the iron core member 16a.

  Thus, the first drive member 11 is unlocked from the second locked portion 11d by the second locking portion 15c of the locking lever 15, and the four springs are biased by the urging force of the set spring 5. The state in which the blades 19 to 22 open the opening 1a is maintained. The state at that time is shown in FIG. In the state of FIG. 2, since the pushing portion 14b of the set member 14 pushes the pushed portion 12b of the second drive member 12, the energization to the coil 16b of the locking lever electromagnet 16 is released. However, the opening 1a is kept fully open, and the subject image can be observed with the electronic viewfinder.

  Thus, the locking lever 15 in the present embodiment brakes the rotation of the first drive member 11 that operates integrally with the second drive member 12 in the final stage of the exposure operation, and drives them at the end of the exposure operation. In order to suppress the bounce of the member and to cover the opening 1a with the four blade members 19 to 22 from when the set operation is started until the imaging information is transferred from the imaging element, When the first drive member 11 is locked and the blade 23 is returned to the set position before the set operation is completed, the drive pin 11b of the first drive member 11 is at the upper end of the elongated hole of the auxiliary base plate 2. Bounding when abutting can be suppressed. Therefore, according to the locking mechanism of the present embodiment, it is possible to prevent the shutter configuration from becoming complicated and large.

  In the state immediately after the completion of the set operation shown in FIG. 2, as already described, in the case of the present embodiment, in the return operation to the set position of the blade 23 performed immediately before the completion of the set operation, The rotation of the first driving member 11 is braked by the second driven portion 15d of the locking lever 15, and the first driving member 11 is locked at the set position by the second locking portion 15c. The bounce of the blades 23 when returned is suppressed, and the time until the blades 23 are stopped is shortened. As a result, according to the focal plane shutter of the present embodiment, the time until the next shooting can be performed is further shortened, and is particularly advantageous for use in an imaging apparatus that can perform continuous shooting.

  In the setting operation of this embodiment, as described above, the setting member 14 is rotated against the urging force of the return spring (not shown) via the link lever 51 of the setting drive mechanism 50. However, the focal plane shutter for an imaging apparatus of the present invention is not limited to such a configuration. As is well known, the image forming apparatus main body side member may be directly pushed and rotated. The return spring for returning the set member 14 to the initial position may be hung on the set member 14 as in this embodiment, but may be hung on the link lever 51 of the set drive mechanism 50. Absent.

  By the way, as already described, the present invention can be implemented as a locking type focal plane shutter, but the above embodiment is configured as a direct type focal plane shutter. In the description of the embodiment, when the locking type focal plane shutter is configured, the setting member is not immediately returned to the initial position after the setting operation is completed, and is similar to the case of the setting member in the embodiment. It has been explained that it is necessary to return to the initial position before the exposure operation is started in the initial stage of photographing. Therefore, it is considered that it is possible to fully understand that the present invention can be implemented as a locking type focal plane shutter only by the description. The configuration for the focal plane shutter will be briefly described.

  First, the iron piece member 13 is not attached to the second drive member 12 as in the present embodiment, but a locked portion is formed instead. Then, in the set completion state of FIG. 11, the second drive member 12 is rotated so that the portion to be locked exceeds the position where the locked portion is locked by the locking lever, and the release button of the imaging device is set. Is pushed, and the setting member 14 is locked to the locking lever at the initial stage when the set member 14 returns to the initial position as in this embodiment. Thereafter, the operation until the set member 14 returns to the initial position is exactly the same as in the case of the above embodiment.

  On the other hand, the lock release member provided to release the lock of the lock lever is provided with a spring before the set member 14 starts returning to the initial position as described above. The blade electromagnet is attracted and held against the force. Thereafter, when the set member 14 operates as described above and returns to the initial position shown in FIG. 4, the energization of the blade electromagnet is cut off. Accordingly, the above-described locking release member is operated by the biasing force of the above-described spring and releases the locking by the above-described locking lever, so that the second drive member 12 starts the exposure operation. Then, during the setting operation, the above-described locking release member is brought into contact with the blade electromagnet in conjunction with the operation of the setting member 14. Various configurations for obtaining such an operation are known, and an example thereof is also described in Japanese Patent Laid-Open No. 2001-215555.

In addition, the present invention includes a bounce deterrent mechanism that can switch between locking and unlocking by one-side energization and that suppresses a bounce caused by an impact when returning to the set direction. The structure of the locking mechanism can be applied to any driving member for the leading blade and the trailing blade.
The present invention can also be applied to a configuration that uses a normally open method to open and close the front blade via the front blade drive member and open and close the rear blade via the rear blade drive member.

DESCRIPTION OF SYMBOLS 1 Ground plate 1a, 2a Opening part 1b Long hole 1c, 1d, 1e, 1f, 1g, 1x Axis 2 Auxiliary ground plate 3 Buffer member 4 Iron core member 11 1st drive member 11a Pushed part 11b Drive pin 11c 1st engagement Stop part 11d 2nd to-be-latched part 11e 2nd push part 11f 1st push part 11g 3rd push part 12 2nd drive member 12a Attachment part 12b Pushed part 12c Push part 13 Iron piece member 14 Set member 14a Mounting portion 14b Pushing portion 15 Locking lever 15a First locking portion 15b Permanent magnet 15c Second locking portion 15d Second driven portion 15e Abutting portion 15f First driven portion 15g Third driven Part 16 Locking lever electromagnet 16a Iron core member 17, 18 Arm 19, 20, 21, 22 Blade member 23 Support plate 24 Ratchet member 50 Set drive mechanism 51 Link lever 51a First lever -51b Second lever 51b-1 Abutting part 52 Slide lever 52a Pushed part 52b Pin 52c Abutting part 53 Cam 53a Pushing part 53a-1 First curved surface area 53a-2 Second curved surface area 54 Gear train 54a, 54b Gear 55a Guide hole 56 Motor 56a Pinion

Claims (4)

  A first drive having a base plate having an opening for a subject optical path, a blade composed of an arm rotatable with respect to the base plate and a blade member connected to the arm, and a pressing portion connected to the blade. A member, a second drive member that is urged in an exposure operation direction by a drive spring and can be operated integrally with the first drive member, and a pushed movement that is pushed by a pushing portion of the first drive member And a latch lever having a permanent magnet and an electromagnet having an iron core that can come into contact with the permanent magnet, and when the first drive member operates integrally with the second drive member, the first The focal plane for an image pickup apparatus, wherein the pushing portion of the driving member pushes the pushed portion of the locking lever until the permanent magnet of the locking lever contacts the iron core of the electromagnet. Shutter.   A locking portion is formed on the locking lever, and a locked portion is formed on the first drive member, and when the permanent magnet of the locking lever contacts the iron core of the electromagnet, 2. The focal plane shutter for an imaging apparatus according to claim 1, wherein a locked portion of the first driving member is positioned at a locking position by the locking lever.   3. The focal plane shutter for an imaging apparatus according to claim 2, wherein the engagement of the locking lever with the first drive member is released by repulsion with respect to the permanent magnet due to energization of the electromagnet. An imaging apparatus comprising the focal plane shutter for an imaging apparatus according to claim 1.

Images