JP2011095717A - Lens cap and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a lens cap which prevents a gap from spoiling appearance, wherein the gap is formed between counter surfaces of adjoining barriers in a state where the barriers close the front of a lens unit, and to obtain an imaging apparatus with the lens cap. <P>SOLUTION: The lens cap includes: a ring-like base 9 attached to an outer circumferential part of a front end of a fixed barrel of the lens unit; and a plurality of barriers 46 supported by shafts so as to open/close the front end opening of the base 9 on the outer circumferential part of the base 9. Each barrier 46, whose outer circumferential part is supported to be rotatable by the shaft 4, is biased to rotate in a direction in which it closes the front end opening of the base 9. When the lens unit is extended to a use position, the barrier is pressed by an outer circumferential part of a front end of a rotary barrel, rotated against biasing force to open the front end opening of the base 9, and separates from a lens holding barrel. In a state where the barriers 46 close the front end opening of the base 9, counter edge parts of the barriers 46 adjoining each other are superimposed when viewed from an optical axis direction of a lens. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens cap used in an imaging apparatus such as various cameras and an imaging apparatus including the lens cap.

  There are some imaging devices such as various cameras that cover the front of the lens with a lens cap because the front of the photographic lens is exposed when not in use and the lens is scratched or dirty. Or there is one with a barrier. Many compact cameras having a retractable lens barrel that have been widely used in recent years are designed to protect the lens by closing the barrier in conjunction with the retracting of the lens barrel.

In the recent camera market, while miniaturization of the camera is required, there is a demand that the zoom lens has a high zoom ratio and that a wide angle of view can be taken. There is a tendency for the torso to become larger. Portability is also an important requirement, and it is also required that a protective member for protecting a finger from touching the front surface of the lens when not in use can be attached. In order to satisfy these requirements, there is a lens barrier that can be incorporated or a lens cap can be attached. However, when a lens barrier is incorporated in the lens unit, the diameter of the front end of the lens becomes large in the case of a wide angle of view lens, so that the barrier itself becomes large, and the driving mechanism of the barrier becomes large, which makes the lens unit bulky. In that respect, an external lens cap can avoid an increase in the size of the lens unit, but the lens cap is mostly detachable by the user and is inferior in operability.
As described above, various devices have been devised for the lens barrier or the lens cap, but there is room for further improvement as is apparent from the invention described in the patent document described below.

  As an example of a camera with a lens barrier provided with a retractable lens barrel, the one described in Patent Document 1 is known. In the invention described in Patent Document 1, a lens cap type lens barrier is attached to a front end outer peripheral portion of a lens barrel to which a lens is fixed so as to be rotatable around an axis perpendicular to the optical axis. . A lens frame that moves forward and backward along the lens barrel and incorporates a lens is incorporated on the inner peripheral side of the lens barrel, and in a state where the lens frame is retracted and stored in the lens barrel, the barrier is When the front end of the lens frame is covered and the lens frame advances from the lens barrel, the barrier is pushed and rotated by the front end of the lens frame to open the front end of the lens frame. In a mode in which the barrier covers the front end of the lens frame and a mode in which the front end of the lens frame is opened, a so-called click mechanism works to temporarily hold each position.

  The invention described in Patent Document 1 is a one-blade type barrier, but Patent Document 2 describes a two-blade lens barrier device. The invention described in Patent Document 2 aims to enable the barrier and the outer surface of the camera to be flush with the barrier closed, and to be used as a lens hood with the barrier open. Yes. In order to achieve this object, each end of the two barriers is supported so as to be rotatable about an axis at the front upper and lower sides of the camera, and these barriers are biased in a direction to close the front surface of the photographing lens. The barrier is opened and closed by an interlocking member that moves in conjunction with the shooting preparation operation and the shooting stop operation. In the shooting preparation operation, the interlocking member interlocks with this to rotate the barrier against the urging force to open the front surface of the photographic lens, and the shooting stop operation rotates the barrier with the urging force to close the front surface of the photographic lens. ing.

  According to the invention described in Patent Document 1, the driving force when the lens cap type barrier operates to the side of opening the lens front surface is obtained from the driving force of the lens unit, and this driving force uses the barrier as its biasing force. It must be able to be driven against. However, the urging force of the barrier is constantly applied to the lens driving mechanism until the barrier is completely opened. Moreover, it is a lens frame that holds the lens at the extreme end of the lens driving mechanism that drives the barrier. This lens barrel is required to have high positional accuracy, and when the positional accuracy deteriorates, the captured image also deteriorates. In the configuration of the invention described in Patent Document 1 in which the barrier is in contact with the lens barrel, the lens urging force is always applied to the lens barrel as an external force when the lens barrel is in a position where photographing is possible. This is disadvantageous for maintaining the accuracy of the position of the lens frame. Further, it is disadvantageous in terms of durability and reliability of the lens unit.

  The invention described in Patent Document 2 is different from the invention described in Patent Document 1 in that the barrier has two blades, but basically, as in the invention described in Patent Document 1, the barrier is closed. Energizing and moving the photographic lens from the retracted position to a position where it can be photographed, and also when it is in a position where it can be photographed, the urging force of the barrier is constantly applied to the lens barrel at the tip, so the lens barrel This is a disadvantageous configuration for maintaining the position of the lens with high accuracy. Further, it is disadvantageous in terms of durability and reliability of the lens unit. Furthermore, in the case of the invention described in Patent Document 2, when the camera is used, the barrier that opens the front surface of the lens barrel does not block part of the illumination light during strobe light emission, It is necessary to prevent the barrier from blocking a part of the optical path for distance measurement, which is a limiting factor in camera design.

  Further, in the lens cap in which the barrier is divided into a plurality of sheets, there is a difficulty in that a gap is generated between the facing edges of adjacent barriers in a state where each barrier closes the front end of the lens. Hereinafter, this difficulty will be described with reference to the drawings. The lens cap shown in FIGS. 30 and 31 includes a ring-shaped base 9 and a barrier 62 divided into three parts for opening and closing the front end portion of the base 9. The base 9 can be attached to and detached from the outer periphery of a lens unit incorporated in an imaging device such as a camera, for example, by a bayonet mechanism. Each barrier 62 has a sector shape in which a disc is equally divided at a central angle of 120 degrees, and the arc-shaped outer portion of each barrier 62 is separated from this axis by a shaft 42 provided in the tangential direction on the outer periphery of the base 9. It is supported so as to be rotatable about the center. Each barrier 62 can open and close the front end of the base 9 by rotating about each shaft 42. Each barrier 62 is biased in a direction to close the front end of the base 9 by a spring biasing force. When the lens unit is extended from the storage position to the use position, the barrier 62 is pushed against the biased force and rotates against the biasing force. Open the front of the lens unit. When the lens unit moves to the storage position, each barrier 62 rotates by the urging force and closes the front of the lens unit.

  32 and 33 show a state in which the barrier 62 is in the closed position, and FIG. 33 is an enlarged view of the opposing edge of the adjacent barrier 62. Opposing edge portions 621 of the respective barriers 62 are formed to be parallel to each other in a state where the lens cap is attached to the lens unit and the front end of the lens unit is shielded by the respective barriers 62. Therefore, in order to be able to open and close the front end of the lens unit by each barrier 62, it is necessary to provide a certain gap between the opposing edge portions 621 of each barrier 62 in a state where the front end of the lens unit is shielded. . Therefore, in a state where the front end of the lens unit is shielded by the barrier 62, the internal lens can be seen from the gap, and the appearance is not good. There is also a problem that dust easily enters from the gap.

  The present invention has been made to solve the problems of the prior art as described above. When the lens unit is in the shooting position, the front surface of the lens unit is opened, and when the lens unit is in the storage position, the lens unit is opened. A lens cap that closes the front of the lens, and when the lens unit is in the shooting position, the lens cap is designed so that the lens cap does not come into contact with the lens barrel that holds the lens. An object of the present invention is to provide a lens cap that can increase the positional accuracy of a cylinder.

  The present invention also devise a structure so that, when the barrier closes the front part of the lens unit, the gap generated on the opposing surfaces of the adjacent barriers does not impair the appearance, and dust does not easily enter from the gap. It is an object to obtain a lens cap that has been manufactured.

  The present invention includes a rotating cylinder that advances and retracts on the inner peripheral side of the fixed cylinder by being driven to rotate around the axis relative to the fixed cylinder, and an axial direction on the inner peripheral side of the rotating cylinder by holding the lens and rotating the rotating cylinder. A lens cap that can be attached to an imaging device including a lens unit that includes a lens holding cylinder that advances and retracts, and a ring-shaped base that can be attached to the outer periphery of a fixed cylinder front end of the lens unit; A plurality of barriers supported by a shaft on the outer periphery so that the front end opening of the base can be opened and closed, and each of the barriers is supported by the shaft so as to be rotatable by the shaft and closes the front end opening of the base And when the lens unit is extended from the storage position to the use position, the lens unit is pushed against the outer peripheral portion of the front end of the rotating cylinder and rotated against the urging force. Each of the barriers is configured so that the opposing edges of the adjacent barriers are in the direction of the optical axis of the lens when the front end opening of the base is closed. The most important feature is that they overlap each other.

Each of the barriers may be divided into three fan shapes having an opening angle with respect to a circular center point, and the outer peripheral portion of each barrier may be rotatably supported by an axis.
In the state where the front end opening of the base is closed, the opposing edges of the adjacent barriers may be divided along an arcuate line so as to draw an arc.

The opposing surface shape of the barriers adjacent to each other in a state where the front end opening of the base is closed may be formed such that one of the barriers adjacent to each other is a convex surface and the other is a concave surface.
The convex surface and the concave surface, which are opposing surfaces of adjacent barriers in a state where the front end opening of the base is closed, may be formed along concentric arcs.
The convex surface and the concave surface, which are opposing surfaces of the adjacent barriers in a state where the front end opening of the base is closed, may be formed along a concentric arc around the rotation center axis of one of the adjacent barriers. .

Each of the barriers may have a rib that overlaps the opposing surfaces in the thickness direction of the adjacent barriers when the front end opening of the base is closed, as viewed from the lens optical axis direction.
The tip end face shape of the rib may be a convex surface on one side of the adjacent barriers and a concave surface on the other side.
The tip end surface shape made of the convex surface of the rib and the tip end surface shape made of a concave surface may be formed along concentric arcs.
The tip surface shape made of the convex surface of the rib and the tip surface shape made of a concave surface may be formed along concentric arcs around the rotation center axis of one of the adjacent barriers.

  The present invention also provides a rotating cylinder that advances and retreats on the inner peripheral side of the fixed cylinder by being driven to rotate about the axis relative to the fixed cylinder, and an axial line on the inner peripheral side of the rotating cylinder that holds the lens and rotates the rotating cylinder. A lens cap that can be attached to an imaging apparatus including a lens unit including a lens holding cylinder that advances and retreats in a direction, and a ring-shaped base that can be attached to an outer peripheral portion of a fixed cylinder front end of the lens unit; A plurality of barriers supported by shafts so that the front end opening of the base can be opened and closed on the outer peripheral part of the base, and each of the barriers is rotatably supported by the shaft, and the lens unit is moved from the storage position. When the lens unit is extended to the use position, it is pushed by the lens unit to open the front end opening of the base, and when the lens unit is in the storage position, the base Each of the barriers is configured such that the front end opening can be closed, and the opposing edges of the adjacent barriers overlap each other when viewed from the lens optical axis direction in a state where the front end opening of the base is closed. .

An imaging apparatus according to the present invention includes a rotating cylinder that advances and retreats on the inner peripheral side of the fixed cylinder by being driven to rotate about an axis with respect to the fixed cylinder, and an inner periphery of the rotating cylinder that holds the lens and rotates the rotating cylinder. A lens unit including a lens holding tube that advances and retreats in the axial direction on the side, and includes a mounting portion that can mount any of the lens caps according to the present invention as described above on the outer peripheral portion of the fixed tube. It is characterized by being.
The lens cap mounting portion may have a bayonet structure.

  According to the present invention, each barrier is configured such that, when the front end opening of the base is closed, the opposing edges of the adjacent barriers overlap each other when viewed from the lens optical axis direction. In a state where the front end opening is closed, when each barrier in the closed position is viewed from the optical axis direction, the lens surface cannot be seen, so that the appearance is improved. There is also an advantage that dust does not easily enter the lens.

  The barrier is divided into a plurality of parts, each outer peripheral part is supported by a shaft and is urged to rotate so as to close the front end opening of the base, and when the lens unit is extended from the storage position to the use position, the front end of the rotating cylinder According to the lens cap configured to be pushed against the outer peripheral portion and rotated against the urging force to open the front end opening of the base and to be separated from the lens holding tube, a barrier is also attached when the lens unit is stored. The lens cap rotates and closes the front end opening of the base, and thus the front end of the lens unit. Further, when the lens unit is extended to the use position, the urging force of the barrier is not applied to the cylinder holding the lens, so that the positional accuracy of the lens holding cylinder at the time of photographing can be improved.

  If each barrier has a structure in which ribs overlap each other when viewed from the lens optical axis direction in the thickness direction of opposing edges of the barriers adjacent to each other when the front end opening of the base is closed, Even if the lens is viewed from an oblique direction, the line of sight is blocked by the ribs so that the lens surface cannot be seen, and the appearance is further improved, and dust does not easily enter the lens.

  According to the imaging apparatus according to the present invention, it is possible to provide an imaging apparatus capable of obtaining the above-described effects by being able to attach the lens cap having the above-described configuration.

  Effects obtained by other modified embodiments of the imaging apparatus according to the present invention will be described in the description of each embodiment.

It is a top view showing typically the 1st example of the lens cap concerning the present invention. It is a perspective view which shows the 2nd Example of the lens cap concerning this invention. It is a front view of the said Example. It is a top view of the said Example. It is a top view which expands and shows the opposing part of the mutually adjacent barrier in the said Example. It is a perspective view which shows the said 2nd Example from the front side. It is a front view which expands and shows a part in FIG. It is a top view which expands and shows the modification of the opposing part of the barrier which can be applied to the said Example adjacent to each other. It is a perspective view which shows the barrier in the said 2nd Example from the front side. It is a perspective view which shows the said barrier from the back side. FIG. 2 is a front view illustrating an imaging device according to an embodiment of the present invention, in a state where a barrier is opened. It is a perspective view which shows the state which the barrier of the said Example opened. It is a perspective view which shows the different operation | movement aspect of the Example of the said imaging device. It is a plane sectional view showing the important section of the above-mentioned imaging device. It is the perspective view which looked at the lens cap which concerns on the said 2nd Example from the back side. It is the perspective view which looked at the lens cap which concerns on the said 2nd Example from another angle of the back side. It is a plane sectional view showing typically the relation between the lens cap concerning the 2nd example, and a lens unit. It is a plane sectional view showing typically the relation between the above-mentioned lens cap and lens unit in a different mode. It is a perspective view which shows the example of the camera which is an imaging device which mounts | wears with the lens cap concerning this invention. It is a perspective view which shows the different operation | movement aspect of the said camera. It is a perspective view which shows the relationship between the said camera and the decoration ring with which this is mounted | worn. It is a perspective view which shows the relationship between the said camera and the decoration ring with which this is mounted | worn from a different angle. It is a perspective view which shows the said decoration ring from a different angle. It is a perspective view which shows the lens unit which can be applied to this invention with a drive mechanism and a part of camera body. It is a longitudinal cross-sectional view of the said lens unit. It is a perspective view which shows a lens unit with a drive mechanism. It is a longitudinal cross-sectional view which shows the different operation | movement aspect of the said lens unit. It is a perspective view which shows the different operation | movement aspect of a lens unit with a drive mechanism. It is a longitudinal cross-sectional view which shows the further different operation | movement aspect of the said lens unit. It is a perspective view showing an example of a lens cap in which a barrier is divided into a plurality of sheets. It is a front view of the lens gap. It is a top view of the said lens gap. It is a top view which expands and shows a part in FIG.

  Embodiments of a lens cap according to the present invention and an image pickup apparatus that can use the lens cap will be described below with reference to the drawings. The illustrated imaging apparatus is configured as a camera, for example, a digital camera. First, the configuration of the lens cap mounting portion of the camera capable of mounting the lens cap according to the present invention will be described mainly.

  19 and 20, the camera 1 incorporates a lens unit 2 on the front side of the body. The lens unit 2 holds the lens and the rotating cylinder 12 that advances and retreats in the axial direction on the inner peripheral side of the fixed cylinder 32 by being rotated around the axis with respect to the fixed cylinder 32 fixed to the body of the camera 1. The lens holding cylinder 30 is moved forward and backward in the axial direction on the inner peripheral side of the rotating cylinder 12 by the rotation of the rotating cylinder 12. The first group lens 3 is held on the inner peripheral side of the lens holding cylinder 30. The rotary cylinder 12 is driven to rotate around its central axis by a motor, and is guided by, for example, a helicoid and advances and retreats in the axial direction. As the rotary cylinder 12 rotates and advances and retreats in the axial direction, the lens holding cylinder 30 advances and retreats in the axial direction, that is, the lens optical axis direction via, for example, a rectilinear cylinder and a cam groove. The rotating cylinder 12 itself does not have a lens holding frame, and therefore does not hold a lens. FIG. 10 shows a storage mode in which the lens unit 2 is retracted to the body side of the camera 1. FIG. 20 shows a mode in which the lens unit 2 can be taken out from the body of the camera 1 and photographed.

  A mounting portion 16 to which various accessories can be attached is provided at the outer peripheral front end portion of the fixed cylinder 32. As with the bayonet mount, the mount 16 is fitted in the optical axis direction with the recess and claw on the accessory side in the claw and recess of the mount 16, and the accessory is moved around the optical axis within a certain angle range. The two are coupled by rotating relative to each other. As described later, the lens cap according to the present invention can be attached to the mount portion 16.

  When the accessory is not attached to the mount portion 16, as shown in FIGS. 21 to 23, it is possible to attach a decorative ring 34 that hides the uneven shape of the mount portion. The decorative ring 34 also has a structure in which the inner peripheral side is adapted to the mount portion 16, and the outer peripheral surface is finished to a smooth and attractive surface. A cutout 36 is formed on the rear end surface in the axial direction of the decoration ring 34. When the decoration ring 34 is fitted to the mount portion 16 in the optical axis direction as described above and rotated around the optical axis by a predetermined angle, the lock pin 38 is fitted into the notch 36 so that the decoration ring 34 is locked. It has become. The lock pin 38 is urged in a direction protruding forward in the mount portion 16.

  A release button 17 is provided near the lock pin 38 on the front surface of the camera 1. The release button 17 and the lock pin 38 are linked to each other. When the release button 17 is pushed in, the lock pin 38 is retracted against the urging force, and the lock of the decoration ring 34 can be released. By releasing this lock, the decorative ring 34 can be rotated in the direction opposite to that when the decorative ring 34 is mounted, and thereby the decorative ring 34 can be removed. The lock and unlock mechanism can also be used for attaching and detaching a lens cap according to the present invention described later.

  As shown in FIGS. 19 and 20, a power button 13, a release button 14, a mode dial 15, a strobe button 24, and the like are disposed on the top surface of the camera 1, and a strobe light emitter 23 is disposed above the mount unit 16. Is arranged. 19 and 20, the strobe light emitter 23 is closed. However, when the strobe button 24 is pressed, the strobe light emitter 23 is activated in a pop-up manner so that the light emitting unit is raised. An auxiliary light exit window 26 for irradiating the subject with auxiliary light, an external distance measuring window (not shown), and the like are arranged on the upper front surface of the camera 1 main body so that the distance can be measured even in the dark. The main distance measurement is performed by processing the output signal of the image sensor in the camera body and searching for the position with the highest contrast. However, since distance measurement takes time, a triangulation method using the external distance measurement window 28 is used. Thus, quick and accurate distance measurement is performed by utilizing the distance measurement result for the internal distance measurement.

  Next, the configuration and operation of the lens unit 2 will be schematically described with reference to FIGS. The configuration of the lens unit 2 is substantially the same as the configuration of the lens barrel described in the specification and drawings of Japanese Patent Application No. 2007-251340. 24 to 29, a lens unit driving motor 90 is mounted in the vicinity of the lens unit 2 in the body of the camera, and the rotational force of the motor 90 is transmitted to the rotary cylinder 12 via the transmission gear train 92. Thus, the rotary cylinder 12 is reversibly driven to rotate. When the rotary cylinder 12 is driven to rotate, the rotary cylinder 12 moves forward and backward in the optical axis direction due to the fitting of the helicoid formed on the fixed cylinder 32 and the rotary cylinder 12. A rectilinear cylinder 94 is fitted on the inner peripheral side of the rotary cylinder 12. The rectilinear cylinder 94 moves together with the rotating cylinder 12 in the optical axis direction, but is relatively rotatable with respect to the rotating cylinder 12 around the optical axis, and is guided by a rectilinear guide in the optical axis direction. It has come to go straight ahead.

  The lens holding cylinder 30 is fitted on the inner peripheral side of the rectilinear cylinder 94. A pin protrudes from the outer periphery of the lens holding cylinder 30 and passes through a rectilinear groove formed in the rectilinear cylinder 94 and further fits into a cam groove formed in the inner periphery of the rotating cylinder 12. waiting. Therefore, the rotating cylinder 12 advances and retreats while rotating, and the rectilinear cylinder 94 moves straight along with the rotating cylinder 12, and the crossing position of the rectilinear groove and the cam groove into which the pin is fitted moves in the optical axis direction. The lens holding cylinder 30 moves in the optical axis direction. The lens holding cylinder 30 holds the first group lens 3. A second group lens is arranged on the inner peripheral side of the rectilinear cylinder 94, and the second group lens moves in the optical axis direction in accordance with the movement of the rotary cylinder 12 and the rectilinear cylinder 94. Since the movement of the lens is not related to the present invention, a description thereof will be omitted. 24 to 27 show a state where the lens unit 2 is retracted and accommodated in the camera body. 28 and 29 show a state in which the lens unit 2 can be taken out from the camera body and photographed.

  Next, various embodiments of the lens cap and embodiments of the imaging apparatus according to the present invention used by being mounted on the camera having the lens unit described above will be described. In each Example, the same code | symbol was attached | subjected to the same component.

  FIG. 1 shows a first embodiment of a lens cap. In FIG. 1, the depiction of the base is omitted, and only two barriers 6 are depicted, and the rotation axes 4 of the respective barriers 6 are depicted as being parallel to each other. Each barrier 6 is formed by equally dividing a disc-like plate with a predetermined opening angle with respect to the center point of the circle, and a portion corresponding to the outer periphery of the disc is a base (not shown). It is supported by the provided shaft 4 and is mounted so as to be rotatable about the shaft 4.

  The base is formed in a ring shape, and can be attached to the lens unit 2 by, for example, a bayonet structure as described above. In the state where the front end opening of the base is closed, each barrier 6 has a cross section of the opposing surface in the thickness direction of each barrier 6 so that opposing edges of the adjacent barriers 6 overlap each other when viewed from the lens optical axis direction. The arc shape is along a concentric circle. More specifically, the shaft 4 is provided at one end side in the thickness direction of each barrier 6, and the opposing surfaces in the thickness direction of adjacent barriers 6 are along arcs around the axis 4 of one barrier 6. It is formed in a circular arc shape.

  An arc 64 shown in FIG. 1 is an arc formed by a surface of one of the barriers 6 rotating on the axis 4 (on the left in the drawing) facing the other barrier, and an arc 65 is the other barrier. 6 shows an arc formed by a surface facing the one barrier. Therefore, the arc 64 and the arc 65 are concentric arcs, and the surface formed by one arc 64 of the adjacent barriers 6 is a convex surface, and the surface formed by the other arc 65 is a concave surface. In FIG. 1, when the left barrier 6 rotates about its axis 4, the edge moves along the arc 64. On the other hand, when the barrier 6 on the right side in FIG. 1 rotates about its axis 4, the trajectory where one corner of the end edge moves is different from the trajectory where the other corner moves. 66, 67.

  In the embodiment shown in FIG. 1, the shape in the thickness direction of the opposing edges of the adjacent barriers 6 in the state where each barrier 6 closes the front end opening of the base is the same as that of one of the adjacent barriers 6. It has an arc shape centered on the rotation center axis 4. Thereby, in the state where the front end opening of the base is closed, each barrier 6 overlaps the opposing edge portions of the adjacent barriers 6 when viewed from the lens optical axis direction. Therefore, when each barrier 6 in the closed position is viewed from the optical axis direction, the lens surface cannot be seen and the appearance is improved, and there is an advantage that dust does not easily enter the lens.

  According to the embodiment shown in FIG. 1, as shown by reference numeral 68 in FIG. 1, it is inclined from the position shifted from the optical axis, more specifically, along the arcs of the opposing edge portions of the adjacent barriers 6. When the gap between the opposing edges is viewed from the direction, the internal lens can be seen through this gap.

  Therefore, in the second embodiment shown below, in a state where the front end opening of the base is closed by each barrier 6, the internal lens cannot be seen through the gap between the opposing edges of the adjacent barriers 6. It is designed to improve its appearance and to prevent dust from entering.

  2 to 7 show a second embodiment. The lens cap according to this embodiment is supported by a shaft 4 so that the front end opening of the base 9 can be opened and closed on the outer peripheral portion of the base 9 and the ring-shaped base 9 that can be attached to the outer peripheral portion of the fixed cylinder front end of the lens unit. The three barriers 46 are provided. Each barrier 46 is divided into three in the shape of a sector having an opening angle of 120 degrees with respect to the center point of the circle, and each outer peripheral portion is supported by the shaft 4 so as to be rotatable with respect to the base 9. Although each barrier 46 has an opening angle of 120 degrees with respect to the center point of the circle, the contours of the opposite edges 462 of the barriers 46 adjacent to each other in a state where the front end opening of the base 9 is closed, The shape of the edge viewed from the rear surface is an arc shape.

  The three barriers 46 complement each other in a state where the front end opening of the base 9 is closed, and are configured so as to form a single disk-like barrier. Furthermore, each barrier 46 has a rib 461 that overlaps in the thickness direction of the opposing edge portion 462 of the barrier 46 adjacent to each other when the front end opening of the base 9 is closed as viewed from the lens optical axis direction. The ribs 461 of one barrier 46 and the ribs 461 of the other barrier 46 that are adjacent to each other are staggered in the thickness direction of the barriers 46, that is, one barrier 46 is in one of the thickness directions and the other barrier 46 is in the thickness direction. Has a rib 461 on the other side in the thickness direction.

  A lens cap is attached by attaching the base 9 to a fixed cylinder of a lens unit such as a camera by a bayonet structure or the like. The mode shown in FIGS. 2 to 7 is a state in which the lens unit is retracted into a main body such as a camera, that is, a storage state, and each barrier 46 is in a state in which the front surface of the lens is closed. Assume that the lens unit is extended from this state to the use state. The lens is extended by rotating the rotating cylinder around the axis with respect to the fixed cylinder of the lens unit. That is, the rotating cylinder is extended on the inner peripheral side of the fixed cylinder by the rotation of the rotating cylinder, and the lens holding cylinder holding the lens on the inner peripheral side of the rotating cylinder advances in the axial direction by the rotation and extension of the rotating cylinder. To do. Each barrier 46 is rotationally biased by a spring so as to close the front end opening of the base 9. When the lens unit is extended from the storage position to the use position, each barrier 46 is pushed against the outer peripheral portion of the front end of the rotary cylinder and is rotated against the urging force to open the front end opening of the base 9 to open the lens holding cylinder. It is comprised so that it may space apart from. When the lens unit is retracted from the use position to the storage position, each barrier 46 is rotated by an urging force to close the front end opening of the base 9. Examples of lens units have already been described with reference to FIGS.

  As described above, each barrier 46 has the rib 461 that overlaps in the thickness direction of the opposing edge 462 of the barrier 46 adjacent to each other when the front end opening of the base 9 is closed as viewed from the lens optical axis direction. . The ribs 461 of one barrier 46 and the ribs 461 of the other barrier 46 that are adjacent to each other are alternately formed in the thickness direction of the barriers 46. Therefore, as shown in an enlarged view in FIG. 5, the ribs 461 of the one barrier 46 and the ribs 461 of the other barrier 46 that are adjacent to each other overlap in the optical axis direction, and are inclined from the optical axis direction or the optical axis direction. Even when the opposite edge 462 of the barrier 46 adjacent to each other is viewed, the inner lens cannot be seen. Therefore, it is possible to improve the appearance in a state in which the front end of the lens unit is shielded by each barrier 46, and the effect of shielding dust entering the lens unit is enhanced. The ribs 461 of the opposing edge portions 462 of the barriers 46 adjacent to each other are provided alternately in the thickness direction.

  If the shape of the front end surface of the rib 461 of each barrier 46 in this embodiment is devised, another effect can be obtained in addition to the effect described above. FIG. 8 shows an example, and the shape of the tip surface of the rib 461 is a convex surface 466 on one side of the barrier 46 adjacent to each other and a concave surface 467 on the other side. Furthermore, the tip surface shape formed by the convex surface 466 and the tip surface shape formed by the concave surface 467 of the rib 461 are formed along concentric arcs. In the example shown in FIG. 8, a rib 461 having a convex surface 466 and a rib 467 having a concave surface 467 are formed along a concentric arc centering on the rotation axis 4 of the right barrier 46, and the convex surface 466 of the right rib 461 is formed. The radius R1 is smaller than the radius R2 of the concave surface 467 of the left rib 461. Therefore, an interval c corresponding to the difference between the radii R1 and R2 occurs in the rotation locus of the convex surface 466 and the rotation locus of the concave surface 467. This interval c is an interval in a direction perpendicular to the lens optical axis. Therefore, even if a time lag occurs in the opening / closing operation of both barriers 46, both ribs 461 do not interfere. Therefore, in addition to the effect of the second embodiment already described, it is possible to obtain an effect that the predetermined opening / closing operation of the barrier 46 can be smoothly performed without interfering with each other.

In FIG. 8, since the length of the barrier 46 in the radial direction is omitted, the dimension (thickness) in the thickness direction with respect to the length of the barrier 46 in the radial direction is drawn abnormally large. The same applies to FIGS. 1 and 5.
In the example of FIG. 8, the tip surface of the rib 461 of each barrier 46 has been described as being formed along a concentric circle with the rotation axis 4 of one barrier 46 as the center, but the tip surface of each rib 461 is described above. If the ribs 461 do not interfere when the barriers 46 are opened and closed, they may be formed along concentric circles centered on the point deviated from the rotation axis.

  For each barrier 46 in the above embodiment, an integrally molded product of the same shape as shown in FIGS. 9 and 10, for example, plastic can be used. 9 and 10, each barrier 46 includes a partial arc-shaped portion along the outer periphery of the base 9 and two arc-shaped edges facing the adjacent barrier 46 in a state where the front end opening of the base 9 is closed. Part 462. Each barrier 46 includes a flat plate-like portion that covers the front end of the lens unit, and the ridge-like edge portion 462 that rises from the outer peripheral edge of the plate-like portion to one surface side (rear surface side) and is continuous over the entire circumference. It has. The height direction of the pier-like edge 462 is the thickness direction of the barrier 46. In one barrier 46, a rib 461 formed on an edge 462 adjacent to another barrier 46 and a rib 461 formed on an edge 462 adjacent to another barrier 46 are: The edges 462 are formed on opposite sides in the thickness direction. In this way, the shapes of the respective barriers 46 can be made the same, and the barriers 46 adjacent to each other are made to be the lens light at the rib 461 in a state where the respective barriers 46 close the front end opening of the base 9. They can be overlapped when viewed from the axial direction.

  As shown in FIG. 10, the barrier 46 has a structure for arranging a spring or the like for rotationally biasing the barrier 46 in a space surrounded by the pier-like edge 462, or a rib for maintaining rigidity. Other appropriate structures are provided. As shown in FIGS. 10, 15, and 16, a rib 463 is integrally formed on the inner surface side of each barrier 46 from the inner surface of the outer peripheral wall toward the inner side in the radial direction. When the rotary cylinder 12 rotates and advances and retracts in the optical axis direction, the outer peripheral portion of the front end of the rotary cylinder 12 is in sliding contact with the rib 463 so that each barrier 46 is opened against the urging force or closed by the urging force. It has become. Following the rib 463 of each barrier 46, a spring hook 464 is integrally formed on the side surface thereof. As shown in FIG. 14, one end of a spring 7 wound around the shaft 4 is hung on the spring hook 464. The other end of the spring 7 is hooked on a spring hook 901 formed near the outer peripheral wall of the base 9. Each barrier 46 is urged to rotate in a direction to close the front end opening of the base 9 by the elasticity of the spring 7.

  Each barrier 46 does not necessarily have to be applied with an urging force as described above. When the lens unit is housed, the barrier 46 is manually closed and locked, and each of the barrier units 46 is moved out of use. The barrier 46 may be pushed by the rotating cylinder to release the lock, and the front of the lens unit may be released.

  According to the second embodiment, as described above, each barrier 46 has an arcuate outline of opposing edge portions 462 of the barriers 46 adjacent to each other when the front end opening of the base 9 is closed. Therefore, when each barrier 46 is in a state where the front end opening of the base 9 is closed, when the barrier 46 is observed from a certain position in front of the barrier 46, the opposing edges 462 of the adjacent barriers 46 continuously change in an arc shape, The state of the gap between the two continuously changes. This makes it difficult to see the internal lens through the gap, and the gap becomes inconspicuous, so that the appearance is improved. FIG. 7 shows an enlarged view of a range surrounded by a dotted circle in FIG. In FIG. 7, the parallel diagonal lines between the opposing edge portions 462 of the adjacent barriers 46 indicate that the above-described gap is inconspicuous. When the thickness dimension of each barrier 46 is increased, that is, the height of the jetty constituting the opposed edge 462 is increased, the above-described effects can be enhanced.

  Next, an embodiment of a camera as an image pickup apparatus including the lens cap according to the above embodiment will be described. As shown in FIGS. 11 to 13, the lens cap has a base 9 attached to the fixed cylinder 16 of the lens unit 2 of the camera 1 by, for example, a bayonet structure. The lens unit 2 has a structure as described above, and holds the lens and the rotating cylinder 12 that moves forward and backward on the inner peripheral side of the fixed cylinder 16 by being driven to rotate around the axis with respect to the fixed cylinder 16. In addition, a lens holding cylinder 30 that advances and retracts in the axial direction on the inner peripheral side of the rotating cylinder 12 by the rotation of the rotating cylinder 12 is provided. The lens holding cylinder 30 holds the first group lens 3 near the inner peripheral front end.

  11 to 13, the lens cap has the same configuration as the lens cap according to the second embodiment. Each barrier 46 of the lens cap is formed into a shape obtained by dividing the disc into three equal parts, that is, a shape that is divided into three substantially fan-shaped with an opening angle of 120 degrees with respect to the center point of the disc. Each barrier 46 is rotatably supported on the ring-shaped base 9 by the shaft 4 at each outer peripheral portion. The direction of each axis 4 is a direction orthogonal to the optical axis direction of the lens unit, and each barrier 46 rotates around the axis 4. Each barrier 46 is rotationally biased by the spring 7 (see FIG. 14) so as to close the front end opening of the base 9. In a state in which the three barriers 46 are rotated by the urging force and the front end opening of the base 9 is closed, the three barriers 46 are combined to form a disk-like barrier.

  FIG. 11 and FIG. 12 both show a mode in which the lens unit 2 is extended from the camera body and each barrier 46 opens the front surface of the lens unit 2. When the power button is pressed to use the camera 1, the motor 90 shown in FIGS. 24, 26, and 28 is activated, and the rotary cylinder 12 is driven to rotate, as already described, and the rotary cylinder 12 and the lens holding unit are held. The tube 30 is extended, and the lens unit 2 is ready for photographing. Each of the barriers 46 is supported so that the arc-shaped edge portion is rotatable at a position close to the body of the camera 1, and the width is narrowed toward the front side of the lens unit 2. The light distribution range (all of which are closed in FIG. 13) does not enter, and the limiting factors in camera design are reduced.

  When the lens unit 2 is extended from the storage position to the use position, each barrier 46 of the lens cap has its rib 463 pushed against the outer peripheral portion of the front end of the rotary cylinder 12 and rotated against the urging force of the spring 7. The front end opening of the base 9 is opened. The ribs 463 of each barrier 46 are configured to be separated from the lens holding cylinder 30. Therefore, the urging force of the barrier 46 is not applied to the lens holding cylinder 30, and the lens holding cylinder 30 and the lens held by the lens 46 can be accurately maintained without being displaced, and deterioration in imaging performance can be avoided. it can. 17 and 18 show the relationship between the rotating cylinder 12 and the rib 463 of each barrier 46. FIG. 17 and 18, reference numeral 121 indicates a contact (sliding contact) position between the rotating cylinder 12 and the rib 463 of each barrier 46.

  The lens cap according to the present invention can be sold and used with a camera as a part of a part mounted on a camera as an imaging apparatus or as a part of a camera. A lens cap alone may be sold separately from the camera, and attached to the camera for use.

DESCRIPTION OF SYMBOLS 1 Camera 2 Lens unit 3 1st group lens 4 Rotating shaft 7 Spring 9 Base 12 Rotating cylinder 30 Lens holding cylinder 32 Fixed cylinder 46 Barrier 461 Rib 462 Opposite edge

JP 2001-21950 A JP 2002-148681 A

Claims (13)

A rotating cylinder that advances and retreats on the inner peripheral side of the fixed cylinder by being driven around the axis with respect to the fixed cylinder, and a lens that holds the lens and advances and retracts in the axial direction on the inner peripheral side of the rotating cylinder by the rotation of the rotating cylinder A lens cap that can be attached to an imaging apparatus including a lens unit including a holding cylinder,
A ring-shaped base attachable to the outer periphery of the front end of the fixed cylinder of the lens unit;
A plurality of barriers supported by a shaft on the outer periphery of the base so that the front end opening of the base can be opened and closed;
Each of the barriers is supported by a shaft so as to be rotatable around a shaft, and is urged to rotate in a direction to close the front end opening of the base, and when the lens unit is extended from a storage position to a use position, It is configured to be pushed against the outer peripheral portion of the front end and rotated against the urging force to open the front end opening of the base and to be separated from the lens holding cylinder,
Each of the barriers is characterized in that, in a state where the front end opening of the base is closed, opposing edges of adjacent barriers overlap each other when viewed from the lens optical axis direction.   2. The lens cap according to claim 1, wherein each of the barriers is divided into three in a fan shape having an opening angle with respect to a center point of a circle, and an outer peripheral portion of each barrier is rotatably supported by a shaft.   3. The lens cap according to claim 1, wherein opposing edges of the barriers adjacent to each other in a state where the front end opening of the base is closed are divided along an arcuate line so as to draw an arc.   4. The lens cap according to claim 1, wherein one of the adjacent barriers is a convex surface and the other is a concave surface in the thickness direction of the barriers adjacent to each other in the state where the front end opening of the base is closed.   The lens cap according to claim 4, wherein the convex surface and the concave surface, which are opposing surfaces of adjacent barriers in a state where the front end opening of the base is closed, are formed along concentric arcs.   The convex surface and the concave surface, which are opposing surfaces of adjacent barriers in a state where the front end opening of the base is closed, are formed along concentric arcs around the rotation center axis of one of the adjacent barriers. The lens cap according to claim 4.   The lens according to any one of claims 1 to 6, wherein each of the barriers has a rib that overlaps the opposing surfaces in the thickness direction of adjacent barriers in a state where the front end opening of the base is closed, as viewed from the lens optical axis direction. cap.   The lens cap according to claim 7, wherein a shape of a tip surface of the rib is a convex surface on one side of the barriers adjacent to each other and a concave surface on the other side.   The lens cap according to claim 8, wherein the tip end surface shape including the convex surface of the rib and the tip surface shape including the concave surface are formed along concentric arcs.   The tip end surface shape made of the convex surface of the rib and the tip end surface shape made of a concave surface are formed along concentric arcs around the rotation center axis of one of the adjacent barriers. Lens cap. A rotating cylinder that advances and retreats on the inner peripheral side of the fixed cylinder by being driven around the axis with respect to the fixed cylinder, and a lens that holds the lens and advances and retracts in the axial direction on the inner peripheral side of the rotating cylinder by the rotation of the rotating cylinder A lens cap that can be attached to an imaging apparatus including a lens unit including a holding cylinder,
A ring-shaped base attachable to the outer periphery of the front end of the fixed cylinder of the lens unit;
A plurality of barriers supported by a shaft on the outer periphery of the base so that the front end opening of the base can be opened and closed;
Each of the barriers is rotatably supported by a shaft, and when the lens unit is extended from a storage position to a use position, the barrier is pushed by the lens unit to open the front end opening of the base. It is configured to be able to close the front end opening of the base when in the storage position,
Each of the barriers is characterized in that the opposing edge portions of the adjacent barriers overlap each other when viewed from the lens optical axis direction when the front end opening of the base is closed. A rotating cylinder that advances and retreats on the inner peripheral side of the fixed cylinder by being driven around the axis with respect to the fixed cylinder, and a lens that holds the lens and advances and retracts in the axial direction on the inner peripheral side of the rotating cylinder by the rotation of the rotating cylinder An imaging apparatus comprising a lens unit including a holding cylinder,
An imaging apparatus comprising: a lens cap mounting portion for mounting the lens cap according to claim 1 on an outer peripheral portion of the fixed cylinder. The imaging apparatus according to claim 12, wherein the lens cap mounting portion has a bayonet structure.

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