JP2008051989A - Shutter device, lens barrel, camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact shutter device capable of preventing a shutter blade from moving inadvertently without getting load in the operation of the shutter blade, and a lens barrel and a camera. <P>SOLUTION: The shutter device is equipped with the shutter blade 7 moving between a closing position where the shutter blade intercepts luminous flux and an opening position where it allows the luminous flux to pass, and a diaphragm blade 4 operated just before operating the shutter blade 7 in the midst of photographing operation. The movement of the shutter blade 7 is restricted by relation between the projection part 2c of a diaphragm driving ring 2 for driving the diaphragm blade 4 and a driving lever 10 for driving the shutter blade 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a shutter device such as a digital camera, a lens barrel, and a camera.

Patent Document 1 discloses a shutter device that drives a shutter blade by an electromagnetic actuator.
However, in the shutter device described in Patent Document 1, since the shutter blades are held in an open state or a closed state by an electromagnetic actuator, the shutter blades may move when an impact is applied. Further, in order to increase the holding force of the shutter blades, a strong magnet is required, and there is a problem that the electromagnetic actuator is increased in size.

On the other hand, a technique for holding a shutter blade by a spring biasing force is known. However, if the spring urging force is applied to the shutter blade, there is a problem that a load is applied when the shutter blade is operated, and the moving speed of the shutter blade becomes slow.
JP 2005-189656 A

  An object of the present invention is to provide a small shutter device, a lens barrel, and a camera that can prevent the shutter blade from inadvertently moving without causing a load when the shutter blade operates.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
According to the first aspect of the present invention, there is provided a shutter blade (7) that moves between a closed position that blocks a light beam and an open position through which the light beam can pass, and a driven device that operates immediately before the shutter blade during a photographing operation. And a member (4), and the movement of the shutter blade is limited by the driven member or the driving member (2) that drives the driven member.
According to a second aspect of the present invention, in the shutter device according to the first aspect, the driven member (4) or the driving member (2) for driving the driven member is moved to the closed position of the shutter blade (7). The shutter device is characterized by restricting movement of the shutter.
According to a third aspect of the present invention, in the shutter device according to the first or second aspect, the driven member (4) is a diaphragm blade of an iris diaphragm that changes an aperture diameter at a position through which the light beam passes. The shutter device characterized by the above.
According to a fourth aspect of the present invention, in the shutter device according to the third aspect, the driving member (2) is an annular ring that rotates around the optical axis of the luminous flux when the diaphragm blade (4) is driven. The ring member is a member that rotates between a restriction position that restricts movement of the shutter blade (7) to the closed position and a release position that does not restrict movement of the shutter blade to the closed position. This is a shutter device characterized by the above.
A fifth aspect of the present invention is the shutter device according to the fourth aspect, further comprising a shutter blade driving member (10) for driving the shutter blade (7), wherein the ring member moves the shutter blade driving member. It is a shutter device characterized by limiting movement of the shutter blade to the closed position by limiting.
According to a sixth aspect of the present invention, in the shutter device according to the fifth aspect, the shutter blade driving member (10) is a lever-like member that rotates when the shutter blade (7) is driven, and the ring member (2) has a protrusion (2c) protruding in the outer diameter direction at the outer peripheral edge portion, and when the ring member is in the restriction position, the shutter blade driving member abuts on the protrusion to When the rotation of the shutter blade driving member is restricted and the ring member is in the release position, the shutter blade driving member can be rotated by the shutter blade driving member not contacting the protrusion. This is a characteristic shutter device.
According to a seventh aspect of the present invention, in the shutter device according to any one of the first to sixth aspects, the restriction on the movement of the shutter blade (7) is released by a first release operation (S1: ON). ), And the movement of the shutter blades is performed in response to the second release operation (S2: ON).
According to an eighth aspect of the present invention, in the shutter device according to the seventh aspect, the first release operation is a half-press operation (S1: ON) of a release button, and the second release operation is performed by a release button. The shutter device is characterized by being fully depressed (S2: ON).
The invention of claim 9 is the shutter device according to any one of claims 3 to 7, wherein the aperture blade (7) has an aperture diameter equal to the optical open aperture diameter (D). Alternatively, the shutter device is characterized in that the restriction on the movement of the shutter blade is released when the aperture blade forms an aperture diameter slightly smaller than the optical open aperture diameter.
A tenth aspect of the present invention is a lens barrel including the shutter device according to any one of the first to eighth aspects.
An eleventh aspect of the present invention is a camera including the shutter device according to any one of the first to eighth aspects.
In addition, you may improve suitably the structure which attached | subjected the code | symbol. In addition, at least a part may be replaced with another component, and the configuration requirements that are not particularly limited with respect to the configuration are not limited to the configurations disclosed in the embodiments.

  According to the present invention, since the movement of the shutter blade is limited by the driven member that operates immediately before the shutter blade during the photographing operation or the driving member that drives the driven member, immediately before the shutter blade operates, The movement limitation of the shutter blades can be released, and it is possible to provide a small lens barrel and camera that can prevent the shutter blades from moving unintentionally without causing a load when the shutter blades are operated.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

(Embodiment)
FIG. 1 is a diagram illustrating a state in which the shutter device of the present embodiment restricts movement of the shutter blades and the shutter blades are in the open position.
FIG. 2 is a diagram illustrating a state in which the shutter device according to the present embodiment releases the restriction on the movement of the shutter blade and the shutter blade is in the closed position.
FIG. 3 is a diagram schematically illustrating a state in which the shutter device of the present embodiment restricts the movement of the shutter blades and the shutter blades are in the open position.
FIG. 4 is a diagram schematically illustrating a state where the shutter device of the present embodiment releases the restriction on the movement of the shutter blades and the shutter blades are in the closed position.
In FIGS. 3 and 4, only one diaphragm blade 4 is left and the other five diaphragm blades 4 are omitted from FIGS. 1 and 2, respectively.
1 to 4 are views as seen from the optical axis direction of a photographing optical system (not shown), and the shutter device of this embodiment only operates in a direction perpendicular to the optical axis shown in these drawings. Therefore, in the following description of the rotation operation and the like, the direction of the rotation axis and the like are not particularly shown, and will be described as the operation in the plane in these drawings.
The shutter device of the present embodiment includes a gear 1, an aperture drive ring 2, a base portion 3, an aperture blade 4, a shutter blade 7 and a drive lever 10, and is provided in a lens barrel of a digital camera (not shown).

The gear 1 meshes with the gear portion 2 a of the aperture driving ring 2, obtains a driving force from a motor (not shown), and transmits the rotational force to the aperture driving ring 2.
The aperture drive ring 2 is an annular member having an opening at the center, and is provided so as to be rotatable with respect to the base 3 around the opening. The aperture drive ring 2 has a gear portion 2a at the outer peripheral edge portion. The gear portion 2a is provided only in a range corresponding to the angle at which the aperture ring 2 is rotationally driven. The diaphragm drive ring 2 has six cam grooves 2b arranged at substantially equal intervals in the circumferential direction. In addition, a protrusion 2 c protruding in the outer peripheral direction is provided on the outer peripheral edge of the aperture driving ring 2.

  The base part 3 is a base part of the shutter device, has an opening part through which a light beam of a photographing optical system (not shown) passes in the center, and is attached to a lens barrel (not shown). The base unit 3 may move according to the zoom operation of the lens barrel or may not move, and can be appropriately selected depending on the configuration of the optical system. In FIG. 1 to FIG. 4, only the outer frame portion of the base portion 3 is shown for easy viewing of the drawings.

The diaphragm blades 4 are members that form an iris diaphragm that changes the aperture diameter at the position through which the light beam passes, and six sheets having the same form are provided. The aperture blade 4 is attached to the base portion 3 so as to be rotatable about a shaft 4a. Further, the diaphragm blade 4 is provided with a cam follower 4 b and is engaged with the cam groove 2 b of the diaphragm drive ring 2.
The shutter blade 7 is a member that opens and closes an opening through which a light beam passes, and two shutter blades 7 are provided. 1 to 4, only one shutter blade 7 is shown for easy viewing of the drawings, and a broken line is shown for easy distinction from other members. The shutter blade 7 has a hole 7a, and is attached to the base portion 3 so as to be rotatable about the hole 7a. The shutter blade 7 has a cam groove 7b. The shutter blade 7 moves between an open position shown in FIGS. 1 and 3 and a closed position shown in FIGS.

  The drive lever 10 is a member that rotates when the shutter blade 7 is driven, and moves the shutter blade 7 between the open position and the closed position, and is attached to the base portion 3 so as to be rotatable about the shaft 10a. It is attached. The drive lever 10 has a shaft 10b at the tip of the lever away from the shaft 10a. The shaft 10b is engaged with the cam groove 7b of the shutter blade 7. Further, the shaft 10b is in contact with the protrusion 2c of the diaphragm drive ring 2 in the state shown in FIGS. In this state, the rotation of the drive lever 10 is restricted, and the shutter blade 7 cannot move to the closed position. A mechanism that drives the drive lever 10 and maintains the state thereof is provided on the opposite side (hereinafter referred to as drive mechanism side) of the side on which the shaft 10b is provided with the base portion 3 interposed therebetween.

FIG. 5 is a schematic diagram showing a mechanism for driving the drive lever 10.
A magnet 10c is provided at the tip of the drive lever 10 on the drive mechanism side. An iron core 11 around which a coil 12 is wound is provided. The coil 12 is energized from the flexible substrate 13. When the drive lever 10 is not driven, the magnet 10c is attracted by the magnetic force to the end 11a or the end 11b of the iron core 11, and the position of the drive lever 10 is maintained. However, the magnetic force of the magnet 10c is necessary to drive the shutter blades 7, but is insufficient to hold the position of the shutter blades 7 when an impact is applied. On the other hand, the drive mechanism shown in FIG. 5 is extremely miniaturized, which is an advantageous form for downsizing the shutter device.
When the drive lever 10 is driven, the coil 12 is energized, and the magnetic pole of the end of the iron core 11 on which the magnet 10c is attracted (the end 11a in the state of FIG. 5) is repelled from the magnetic pole of the magnet 10c. At the same time, the drive lever 10 is driven by bringing the end of the iron core 11 opposite (the end 11b in the state of FIG. 5) and the magnetic pole of the magnet 10c together. Therefore, by changing the energization direction (positive or negative), the magnet 10c moves and the drive lever 10 can be rotated in an arbitrary direction.

Next, the operation of the camera provided with the shutter device of this embodiment will be described.
The camera having the shutter device of the present embodiment has a liquid crystal display unit (not shown), and displays an image obtained by an image sensor (not shown) so that it can be used for composition confirmation before shooting a still image. So-called through image display can be performed. Therefore, in a state where the camera is turned on and a live view image is displayed, the shutter blade 7 is in the open position shown in FIGS. 1 and 3 in order to form a subject image on the image sensor. At this time, the aperture blade 4 forms an aperture diameter larger than the optical open aperture diameter D. The optical open aperture diameter is formed by a fixed aperture (not shown) whose aperture diameter does not change.
FIG. 6 is a flowchart showing the operation when the release button is pressed from the state in which the through image is displayed.

  In S10, it is determined whether or not a switch S1 that is turned on by half-pressing a release button (not shown) is turned on. Note that the camera of this embodiment is provided with a release button (not shown). The release button is a two-stage push-in type button, and includes a switch S1 that is turned on by half-pressing the first stage and a switch S2 that is turned on by fully pressing the second stage. When S1 is turned on, an autofocus operation or the like by an unillustrated autofocus mechanism is performed, and there is a high possibility that shooting will be performed immediately after that (S2 is turned on). The possibility of shooting is reduced. If S1 is OFF, the process proceeds to S20, and if S1 is ON, the process proceeds to S40.

  In S20, the gear 1 rotates to rotate the aperture drive ring 2, and the aperture drive ring 2 rotates to the position (restricted position) shown in FIGS. At this time, the cam follower 4b moves following the cam groove 2b, and the six diaphragm blades 4 form an opening diameter larger than the optical opening diameter D. At this time, the protrusion 2c of the aperture driving ring 2 is in a position where the shaft 10b comes into contact when the drive lever 10 rotates in a direction to move the shutter blade 7 to the closed position, and the shutter blade 7 moves to the closed position. (S30).

In S40, in response to S1 being turned ON, the gear 1 rotates to rotate the aperture drive ring 2, and the cam follower 4b moves following the cam groove 2b, with an opening diameter equal to or less than the optical opening diameter D. Thus, the six aperture blades 4 move to a position where the aperture diameter corresponds to the aperture value (F value) set by the camera. Here, in the present embodiment, if the aperture diameter formed by the aperture blade 4 is equal to or smaller than the optical open diameter D, the protrusion 2c has moved to a position where the shaft 10b of the drive lever 10 does not contact. Therefore, if the aperture drive ring 2 moves to a position (release position) where the aperture diameter formed by the aperture blade 4 is equal to or less than the optical opening diameter D, the shutter blade 7 can move to the closed position, and the shutter The locking of the blade 7 is released (S50).
Note that the aperture diameter formed by the aperture blade when the shutter blade 7 is unlocked is equal to the optical open diameter D, or the aperture diameter formed by the aperture blade is slightly smaller than the optical open diameter D. It is desirable to make it small. This is because by doing so, it is not necessary to rotate the aperture driving ring 2 greatly, and the shutter time lag can be shortened.

In S60, it is determined whether or not a switch S2 that is turned on by fully pressing a release button (not shown) is turned on. If S2 is ON, the process proceeds to S70, and if S2 is OFF, the process returns to S10.
In S70, data obtained from an image sensor (not shown) is acquired, and the drive lever 10 is rotated so that the exposure time determined by the camera is reached, thereby moving the shutter blade 7 to the closed position. Then, image processing or the like is performed on the data obtained as necessary, and the image data is recorded on a recording medium or the like.

As described above, in the present embodiment, when S1 = OFF, the shutter blade 7 does not move to the closed position due to the relationship between the protrusion 2c and the shaft 10b. Therefore, when the through image is displayed, for example, even if an impact is applied to the camera, the shutter blade 7 does not move to the closed position. If the shutter blade 7 is moved to the closed position during live view display, the subject light does not reach the image sensor and the subject image cannot be displayed on the display screen. In the form, such a phenomenon can be prevented.
Further, in the present embodiment, in the state where the restriction on the movement of the shutter blade 7 is released, the protrusion 2c of the aperture driving ring 2 does not become a load with respect to the movement of the shutter blade 7 and moves the shutter blade 7 at a high speed. Can be made.
Furthermore, in the present embodiment, since the movement of the shutter blade 7 can be limited only by providing a small number of protrusions 2c on the aperture driving ring 2 necessary for driving the aperture, the shutter device having high reliability as described above. Can be realized without increasing the size.
Furthermore, in the present embodiment, the movement of the shutter blade 7 is limited by the diaphragm drive ring 2 that drives the diaphragm blade 4 that operates immediately before the shutter blade 7 operates. Therefore, even when the release button is pushed in at once and S1 and S2 are turned on almost simultaneously, the movement of the aperture blade 4 and the release of the movement restriction of the shutter blade 7 are performed simultaneously, and the shutter blade 7 is closed thereafter. The movement to the position can be performed by a continuous operation.

(Deformation)
The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
(1) In the present embodiment, the shutter device has shown an example in which the movement of the shutter blade 7 to the closed position is limited by the aperture drive ring 2, but the present invention is not limited to this, for example, the movement of the shutter blade to the open position May be restricted.

(2) In the present embodiment, the shutter device has shown an example in which the movement of the shutter blade 7 is restricted by restricting the rotation of the drive lever 10 by the diaphragm drive ring 2. The movement of the shutter blade may be directly limited by the blade.

(3) In the present embodiment, an example in which the shutter device restricts the movement of the shutter blade 7 by restricting the rotation of the drive lever 10 by the diaphragm drive ring 2 is not limited to this. The movement of the shutter blades may be limited by another driven member or the like such as a member related to an AF mechanism that operates immediately before the shutter blades in operation.

It is a figure which shows the state which the shutter apparatus of this embodiment restrict | limits the movement of a shutter blade | wing, and a shutter blade | wing exists in an open position. It is a figure which shows the state which the shutter apparatus of this embodiment cancel | releases the restriction | limiting of the movement of a shutter blade | wing, and a shutter blade | wing is in a closed position. It is a figure which simplifies and shows the state which the shutter apparatus of this embodiment restrict | limits the movement of a shutter blade | wing, and a shutter blade | wing is in an open position. It is a figure which simplifies and shows the state which the shutter apparatus of this embodiment cancel | releases the restriction | limiting of a movement of a shutter blade | wing, and a shutter blade | wing is in a closed position. 4 is a schematic diagram showing a mechanism for driving the drive lever 10. FIG. It is a flowchart which shows operation | movement when a release button is pushed from the state by which a through image is displayed.

Explanation of symbols

1: gear, 2: aperture drive ring, 2c: protrusion, 4: aperture blade, 7: shutter blade, 10: drive lever, 10b: shaft

Claims (11)

A shutter blade that moves between a closed position that blocks a light beam and an open position through which the light beam can pass;
A driven member that operates immediately before the shutter blades during a photographing operation operate;
With
Limiting the movement of the shutter blades by the driven member or the driving member that drives the driven member;
A shutter device characterized by the above. The shutter device according to claim 1,
The driven member or the driving member that drives the driven member restricts movement of the shutter blade to the closed position;
A shutter device characterized by the above. In the shutter device according to claim 1 or 2,
The driven member is a diaphragm blade of an iris diaphragm that changes an aperture diameter of a position through which the light beam passes;
A shutter device characterized by the above. The shutter device according to claim 3.
The drive member is an annular ring member that rotates around the optical axis of the light beam when driving the diaphragm blades;
The ring member rotationally moves between a restriction position that restricts movement of the shutter blades to the closed position and a release position that does not restrict movement of the shutter blades to the closed position;
A shutter device characterized by the above. The shutter device according to claim 4,
A shutter blade driving member for driving the shutter blade;
The ring member restricts movement of the shutter blade to the closed position by restricting movement of the shutter blade driving member;
A shutter device characterized by the above. The shutter device according to claim 5,
The shutter blade driving member is a lever-like member that rotates when driving the shutter blade,
The ring member has a protrusion protruding in the outer diameter direction at the outer peripheral edge portion,
When the ring member is in the restricting position, the shutter blade driving member abuts against the protrusion to restrict rotation of the shutter blade driving member,
When the ring member is in the release position, the shutter blade driving member can be rotated by preventing the shutter blade driving member from coming into contact with the protrusion.
A shutter device characterized by the above. In the shutter device according to any one of claims 1 to 6,
The release of the restriction on the movement of the shutter blades is performed in response to the first release operation,
The shutter blades are moved in response to a second release operation;
A shutter device characterized by the above. The shutter device according to claim 7.
The first release operation is a half-press operation of a release button,
The second release operation is a full pressing operation of a release button;
A shutter device characterized by the above. In the shutter device according to any one of claims 3 to 7,
When the aperture blade has an aperture diameter equal to the optical open aperture diameter, or when the aperture blade has an aperture diameter slightly smaller than the optical open aperture diameter, the restriction on the movement of the shutter blade is released. Being
A shutter device characterized by the above.   A lens barrel comprising the shutter device according to any one of claims 1 to 8. A camera comprising the shutter device according to any one of claims 1 to 8.

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