JP2005070594A - Barrier mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a barrier mechanism enabled to be comfortably operated even when a foreign substance such as sand enters from an aperture part 106a in the opened state of a barrier or even when the foreign substance is caught in gear parts 101b, 102b and a lens barrel is collapsed. <P>SOLUTION: The wall of a barrier driving member is formed on a position corresponding to the optical path side of the engaging gear part of a main driving barrier member and a driven barrier member in the opened state of a lens barrier. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus such as a digital still camera and a video camera.

  Conventional compact cameras are generally of a type in which a barrier mechanism for opening and closing the lens opening is provided on the front surface of the lens barrel. This barrier mechanism generally shifts a plurality of barrier blades from a closed state to an open state in conjunction with the movement of the lens barrel from the non-photographing position to the photographing position.

  A conventional barrier mechanism will be described with reference to FIGS. The main barrier 101 and the sub-barrier 102 are fixed to a base plate (not shown) so as to be rotatable about the rotation centers 101a and 102a. It is disposed immediately before the barrier 102. The main barrier 101 and the sub-barrier 102 are engaged with each other by gear portions 101 b and 102 b, and when the main barrier 101 is rotated, the rotational force is transmitted to the sub-barrier 102. An opening / closing lever 103 that is rotatable about the same rotation center as the main barrier 101 is attached to the back of the main plate, and this opening / closing lever 103 is urged counterclockwise in the figure by a drive spring 104. Yes. The open / close lever 103 is formed with a drive shaft 103a extending forward, and the drive shaft 103a is inserted into an absorption hole 101c formed in the main barrier 101 through a long hole formed in a ground plate (not shown). Match. A countersink portion (not shown) is formed on the back surface of the main barrier 101, and an absorption spring 105 having a wire spring shape is accommodated in the countersink portion. The absorption spring 105 is fixed to the main barrier 101 by a fixing portion 105a, and the operating portion 105b is connected to the fixing portion 105a. Further, the absorption spring 105 generates an urging force indicated by an arrow f ′ in the operating portion 105b in a normal state (as shown in FIGS. 9 and 10) attached to the main barrier 101, and this urging force f ′ is The drive shaft 103a of the open / close lever 103 acts so as to contact the end surface of the absorption hole 101c of the main barrier 101. As a result, the opening / closing lever 103 and the main barrier 101 can be rotated together, and the sub-barrier 102 can be further rotated.

Next, the opening / closing operation of the conventional barrier mechanism will be described. When the lens barrel moves to a non-photographing position, that is, when the lens barrel performs a retraction operation, the power that opposes the drive spring 104 from the lens barrel (the retraction force of the lens barrel or the rotation from the focusing motor) When the opening / closing lever 103 rotates in the clockwise direction in response to the force, the drive shaft 103a also rotates in the clockwise direction, and the main barrier 101 rotates in the clockwise direction together with the driving shaft 103a. The barrier 102 rotates counterclockwise, and the barrier is closed as shown in FIG. When the lens barrel moves to the photographing position, that is, when the lens barrel is extended, the open / close lever 103 released from the power of the lens barrel is urged to rotate counterclockwise to the drive spring 104. Together with this, the main barrier 101 rotates counterclockwise and the sub-barrier 102 rotates clockwise, resulting in the barrier open state shown in FIG.
JP-A-9-212536

  However, in the conventional example, since the gear portions 101b and 102b of the main barrier 101 and the sub-barrier 102 are exposed in the barrier open state of FIG. 10, when a foreign substance such as sand enters from the opening 106a. There was a problem that the barrier could not be completely closed even if the lens barrel was retracted because foreign matter was caught between the gear portions 101b and 102b because this could not be blocked.

  Further, in the above conventional example, since the opening / closing lever 103 has substantially the same rotation center as the main barrier 101, the drive spring 104 that needs to be disposed in the vicinity of the opening / closing lever 103 is structurally configured as a barrier. It cannot be arranged outside the operation area of the main barrier 101 and the sub-barrier 102 including the moving part. For this reason, as shown in FIG. 11, the drive spring 104 must be disposed behind the main barrier 101, the sub-barrier 102, and the ground plane (not shown). Even if the opening / closing lever 103 is made thin, only the thickness of the winding diameter of the drive spring 104 is required at a minimum. A method of reducing the spring thickness by reducing the wire diameter or winding diameter of the tension spring (the drive spring 104) can be considered. There is a risk that it cannot be fully utilized.

  Therefore, the present invention provides a barrier mechanism that opens and closes two barriers, a main barrier and a driven barrier, connected by a gear, by rotating a substantially ring-shaped barrier drive member around the optical axis in a barrier open state. The first object is to provide a barrier mechanism that operates comfortably even if foreign matter such as sand enters by providing a wall on the barrier drive member at a position corresponding to the optical path side of the connecting gear portion. A barrier mechanism that opens and closes two barriers, a main barrier and a driven barrier, connected by a gear, by rotating a substantially ring-shaped barrier driving member around the optical axis, wherein the main barrier is in an open state. And the position in the barrier closed state of the portion that connects the member that urges the barrier driving member in the barrier opening direction to the barrier driving member overlap in a plane perpendicular to the optical axis. A second object is to provide a barrier mechanism that prevents the enlargement in the radial direction and is thinned.

  According to a first aspect of the present invention, there is provided a driving barrier member and a driven barrier member connected to each other by a gear provided at each base end, and the main driving barrier. When the driven barrier member rotates together with the rotation of the member, it can be opened and closed between a closed position that blocks the optical path of the imaging optical system and an open position that retreats outward. A lens barrier, and a barrier driving member that is formed in a substantially ring shape, rotates about the optical axis, and opens and closes the main barrier member by a driving member provided in a part of the ring member; The barrier drive member is provided with a wall at a position corresponding to the optical path side of the coupling gear portion of the main driving barrier member and the driven barrier member in the open state of the lens barrier. In the barrier mechanism that.

  According to this configuration, even if foreign matter such as sand enters the barrier, the foreign matter is not caught in the connecting gear portion of the barrier, and the barrier is not completely closed even when the lens barrel is retracted. Is possible.

  According to another aspect of the present invention for realizing the object of the present invention, a driving barrier member and a driven barrier member connected to each other by a gear provided at each base end are provided, as described in claim 2. When the driven barrier member rotates together with the rotation of the main barrier member, it opens and closes between a closed position that blocks the optical path of the photographic optical system and an open position that retreats outward. A lens barrier that is possible, and a barrier drive that is formed in a substantially ring shape, rotates about the optical axis, and opens and closes the main barrier member by a drive member provided in a part of the ring member. A driving mechanism and a main driving barrier member when the main driving barrier member is driven to the open position and directly driven by the driving member. With an elastic member between In the barrier mechanism, characterized in that drive.

  According to this configuration, the driving spring is driven by the barrier driving member that rotates about the optical axis, instead of the driving spring that has been conventionally limited by the opening / closing lever. The degree of freedom of the arrangement increases, and the barrier mechanism can be made thinner.

  A specific configuration for realizing the object of the invention according to the present application is as described in claim 3, wherein the main driving barrier member, the driven barrier member, the elastic member, and a part of the barrier driving member are used. A drive member and at least a part of a mechanism for biasing the barrier drive member in the barrier opening direction share a region with respect to the direction of the optical axis. 2. The barrier mechanism according to item 2.

  According to this configuration, it is possible to reduce the thickness of the barrier mechanism while suppressing the dimension in the thickness direction of the barrier mechanism.

  A specific configuration for realizing the object of the invention according to the present application is as described in claim 4, wherein the position of the main driving barrier member in the barrier open state and the barrier driving member are urged in the barrier opening direction. The barrier mechanism according to any one of claims 1, 2, and 3, wherein a position of a portion connecting the member to be connected to the barrier driving member overlaps a position in a barrier closed state in a plane perpendicular to the optical axis. .

  According to this configuration, it is possible to reduce the thickness of the barrier mechanism without increasing the size in the radial direction.

  As described above, according to the present invention, even if a foreign substance such as sand enters the barrier, the barrier is closed even if the lens barrel is retracted without the foreign substance being caught in the connecting gear portion of the barrier. There is an epoch-making effect that can be prevented from being lost.

  The best mode for carrying out the invention will be described below.

  FIG. 1 is a configuration perspective view of a barrier mechanism in the present embodiment. FIG. 2 is a perspective view of the main barrier blade viewed from the back side. FIG. 3 is a front view of the absorption spring. FIG. 4 is a front view of the barrier closed state. FIG. 5 is a front view with the barrier opened. FIG. 6 is a perspective view of the auxiliary barrier blade viewed from the back side. FIG. 7 is a right side view of the barrier closed state. FIG. 8 is an auxiliary detail view in the barrier open state.

  The drive member 5 is incorporated so as to be rotatable in the circumferential direction with the outer peripheral surface of the lens holding portion 6 b of the lens barrel 6 as a sliding surface, and both ends of the barrier opening spring 7 are pins of the lens barrel 6. 6a and a hook 5a formed on the drive member 5 are always urged to rotate clockwise. The base member 4 is disposed on the front surface of the lens holding portion 6b and is attached to the lens barrel 6 by a bayonet method. When the base member 4 is mounted, the driving member 5 is sandwiched between the lens barrel 6 and the base member 4 and is regulated in the optical axis direction. The main barrier blade 1 and the sub barrier blade 2 are disposed on the front surface of the base member 4, and holes 6 a and 6 d (having an axis parallel to the optical axis) projecting from the lens barrel 6 have holes 1 a, 2a is rotatably supported. The main barrier blade 1 and the sub barrier blade 2 are engaged with each other by gear portions 1 b and 2 b, and when the main barrier blade 1 is rotated, the rotational force is transmitted to the sub barrier blade 2. The drive member 5 is formed with a drive pin 5b extending in front of the lens barrel in parallel with the optical axis and a dustproof wall 5c having a predetermined length in the circumferential direction. The drive pin 5b and the dustproof wall 5c are The drive pin 5b contacts the end surface 1d formed in the main barrier blade 1 through the long hole 4a formed in the base member 4. As shown in FIG. 2, a countersink portion 1e is formed on the back surface of the main barrier blade 1, and an absorption spring 3 having a wire spring shape is attached to the countersink portion 1e. The absorption spring 3 includes a hook portion 3a fixed to a fixing portion 1f formed on the main barrier blade 1, and an operation portion 3b connected to the hook portion 3a. The absorption spring 3 has a shape indicated by a broken line in FIG. 3 in an undeformed state, and a shape indicated by a solid line in a normal state (state as shown in FIGS. 4 and 5) attached to the main barrier blade 1. To generate an urging force indicated by an arrow f in the operating portion 3b. As shown in FIG. 5, the urging force f acts to keep the drive pin 5 b of the drive member 5 in contact with the end surface 1 d of the main barrier blade 1. Thereby, the drive member 5 and the main barrier blade 1 can rotate integrally, and further, the sub-barrier blade 2 can be rotated. Then, by making the tip of the operating part 3b of the absorption spring 3 bent, the operating part 3b is not seen from the opening 8a of the cover member 8 in the barrier open state of FIG. The urging force f is always maintained at approximately 90 degrees with respect to the radial direction of the drive member 5 in both the barrier closed state of FIG. 4 and the barrier open state of FIG. It can act on the drive pin 5b. Further, as shown in FIG. 6, a countersink portion 2 c is formed on the back surface of the first sub-barrier blade 2, and in the barrier closed state of FIG. 4, the dust-proof wall 5 c and the operating portion 3 b of the absorption spring 3 The structure absorbs the thickness in the optical axis direction. The cover member 8 has an opening 8a at the center centered on the optical axis of the optical system, and is arranged at a position immediately before the main barrier blade 1 and the sub barrier blade 2 in phase with the base member 4. Is done. In this way, by configuring the barrier device according to the present invention, as shown in FIG. 7, the barrier opening spring 7 is within the thickness of the main barrier blade 1, the sub barrier blade 2, and the drive member 5 in the optical axis direction. Can be arranged. Thereby, the barrier mechanism can be made thin in the optical axis direction.

  Next, the opening / closing operation of the barrier mechanism of this embodiment will be described. When the lens barrel 6 moves to a non-photographing position, that is, when the lens barrel 6 performs a retraction operation, the lens barrel 6 protrudes radially outward from the outer peripheral portion of the drive member 5 and is axially moved along the optical axis. The oblique cam surface 5e formed on the cam 5d extending to the rear side of the lens barrel is engaged with the cam surface formed on the camera body (not shown), so that the drive member 5 rotates counterclockwise. The main barrier blade 1 rotates in the clockwise direction and the sub-barrier blade 2 rotates in the counterclockwise direction so as to cover the opening 8 a of the cover member 8. At this time, the amount of rotation of the drive member 5 should be set to an amount that the main barrier blade 1 and the sub barrier blade 2 are just opened and closed. Therefore, it is necessary to set the rotation amount of the drive member 5 to be large in view of the margin. Therefore, the end face 1d in contact with the barrier in the opened state of FIG. 5 and the drive pin 5b are slightly separated in the closed state of the barrier in FIG.

  When the lens barrel 6 is moved to the photographing position, that is, when the lens barrel 6 is extended, the rotation is restricted by being engaged with a cam surface formed on a camera body (not shown). The drive member 5 is urged to rotate in the clockwise direction by the barrier opening spring 7, and the main barrier blade 1 rotates in the counterclockwise direction together with the drive member 5 and the sub-barrier blade 2 rotates in the clockwise direction. It rotates and it will be in the barrier open state shown in FIG. As shown in FIGS. 4 and 7, the operation area of the main barrier blade 1 overlaps with the hook 5 a of the drive member 5 in the optical axis direction in the optical axis direction. The barrier device does not increase in size in the radial direction, and the function of the barrier device is realized by rotating the clockwise direction and the tip of the main barrier blade 1 enters the space where the hook 5a escapes. It is possible to obtain a spring force of the barrier opening spring that can sufficiently satisfy the above. Further, in the closed state of FIG. 4, the dust-proof wall 5c accommodated in the countersink portion 2c of the sub-barrier blade 2 is in contact with the main barrier blade 1 in the barrier open state as shown in FIGS. It rotates so that it may be located in the inner peripheral side of the gear parts 1b and 2b of the sub barrier blade 2. Thereby, it is possible to prevent foreign matters such as sand entering from the opening 8a of the cover member 8 from being caught between the gear portions 1b and 2b in the barrier open state.

  That is, if comprised as mentioned above, it is provided with the main barrier member and the driven barrier member which were connected with the gear provided in each base end, and the main barrier member rotates and is integrated with the above By rotating the driven barrier member, a lens barrier that can be opened and closed between a closed position that blocks the optical path of the photographing optical system and an open position that retreats outward from this is formed in a substantially ring shape, A barrier mechanism comprising a barrier driving member that rotates about the optical axis and that opens and closes the main barrier member by a driving member provided in a part of the ring-shaped member, the lens When the barrier is in an open state, the barrier driving member is provided with a wall at a position corresponding to the optical path side of the coupling gear portion of the main driving barrier member and the driven barrier member. Even enters the A, without foreign matters become caught engaged gear of the barrier, there is an effect that it is possible to prevent the lens barrel does not fit close the barriers be retracted.

  The driven barrier member includes a driven barrier member and a driven barrier member that are connected to each other by a gear provided at each base end, and the driven barrier member rotates integrally with the rotation of the driven barrier member. The lens barrier that can be opened and closed between a closed position that blocks the optical path of the photographic optical system and an open position that retreats outward from this, and is formed in a substantially ring shape and rotates about the optical axis. A barrier mechanism comprising a driving member provided on a part of the ring-shaped member, and a barrier driving member for opening and closing the main driving barrier member, wherein the main driving barrier member is driven to an open position. When driving to the closed position, the driving member is driven by an elastic member between the driving member and the main driving barrier member. Bari Driving the main barrier with a barrier drive member that rotates around the optical axis increases the degree of freedom in the arrangement of the drive springs, resulting in a thin barrier mechanism. There is an effect that can be achieved.

  In addition, the main driving barrier member, the driven barrier member, the elastic member, a driving member that is a part of the barrier driving member, and further for biasing the barrier driving member in the opening direction of the barrier By adopting a configuration in which at least a part of the mechanism shares an area with respect to the direction of the optical axis, there is an effect that the barrier mechanism can be reduced in thickness by suppressing the dimension in the thickness direction of the barrier mechanism.

  Further, the position of the main barrier member in the barrier open state, the position in the barrier closed state of the portion connecting the member for urging the barrier driving member in the barrier opening direction to the barrier driving member, and the optical axis By overlapping in an orthogonal plane, there is an effect that the barrier mechanism can be thinned without increasing the size in the radial direction.

It is a structure perspective view of the barrier mechanism in a present Example. It is the perspective view which looked at the main barrier blade | wing in a present Example from the back side. It is a front view of the absorption spring in a present Example. It is a front view in the barrier closed state in a present Example. It is a front view in the barrier open state in a present Example. It is the perspective view which looked at the sub barrier blade | wing in a present Example from the back side. It is a right view in the barrier closed state in a present Example. It is an auxiliary | assistant detailed drawing in the barrier open state in a present Example. It is a front view in the barrier closed state in a conventional example. It is a front view in the barrier open state in a conventional example. It is a right view in the barrier closed state in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main barrier blade 2 Sub barrier blade 3 Absorption spring 4 Base member 5 Drive member 6 Lens barrel 7 Barrier opening spring 8 Cover member 101 Main barrier 102 Sub barrier 103 Opening / closing lever 104 Drive spring 105 Absorption spring 106 Cover member

Claims (4)

A primary barrier member and a secondary barrier member connected by gears provided at each base end;
When the driven barrier member rotates integrally with the rotation of the main driving barrier member, it is between a closed position where the optical path of the photographing optical system is blocked and an open position where the optical path is retracted outwardly. A lens barrier that can be opened and closed, and a barrier that is formed in a substantially ring shape, rotates about the optical axis, and opens and closes the main driving barrier member by a driving member provided in a part of the ring shaped member. A drive member,
A barrier mechanism characterized in that, in the open state of the lens barrier, a wall is provided on the barrier driving member at a position corresponding to the optical path side of the connecting gear portion of the main barrier member and the driven barrier member. A primary barrier member and a secondary barrier member connected by gears provided at each base end;
When the driven barrier member rotates integrally with the rotation of the main driving barrier member, it is between a closed position where the optical path of the photographing optical system is blocked and an open position where the optical path is retracted outwardly. A lens barrier that can be opened and closed, and a barrier that is formed in a substantially ring shape, rotates about the optical axis, and opens and closes the main driving barrier member by a driving member provided in a part of the ring shaped member. With a drive member,
When the main driving barrier member is driven to the open position, it is driven directly by the driving member, and when it is driven to the closed position, it is driven via an elastic member between the driving member and the main driving barrier member. A barrier mechanism characterized by   The main driving barrier member, the driven barrier member, the elastic member, a driving member that is a part of the barrier driving member, and a mechanism for biasing the barrier driving member in the opening direction of the barrier. The barrier mechanism according to claim 2, wherein at least a part shares a region with respect to the direction of the optical axis.   The position of the main barrier member in the barrier open state and the position in the barrier closed state of the portion connecting the member for urging the barrier driving member in the barrier opening direction to the barrier driving member are orthogonal to the optical axis. The barrier mechanism according to claim 1, wherein the barrier mechanism overlaps in a plane.

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