JP2011027863A - Lens barrel and imaging apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel in which an iris unit can be inserted into the lens barrel from a direction perpendicular to an optical axis, even in the configuration in which a portion of a zoom lens-moving frame is stored in the reel portion of the iris unit at the maximum telescopic state. <P>SOLUTION: The lens barrel includes: a fixed frame 103; a contact portion 103a provided on the fixed frame; the moving frame 110 that moves within the fixed frame 103 in the direction of the optical axis L; and a movable portion 110c provided on the moving frame 110. When the moving frame 110 is moved in the direction of the optical axis L, the movable portion 110c is in the position which can come into contact with the contact portion 103a in a first position, and is in the position which does not come into contact with the contact portion 103a in a second position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens barrel used in an imaging apparatus, and more particularly to a lens barrel including a moving lens group.

  Japanese Patent Application Laid-Open No. H10-228561 discloses a lens driving device that moves a lens holding frame in the optical axis direction along a guide axis. The rack provided on the lens holding frame is engaged with the lead screw, and the lead screw is rotated by the drive source, whereby the lens holding frame moves in the optical axis direction. One coil spring is used to remove the backlash of the rack and to mesh the rack with the lead screw without backlash.

JP-A-5-027149

  In order to shorten the optical total length of the lens barrel, it is desirable that the zoom lens moving frame be as close as possible to the iris unit in the state where the focal length of the lens barrel is longest, that is, in the maximum telephoto state. For this reason, the iris unit may be provided with a countersink portion that houses a part of the zoom lens moving frame. However, with such a configuration, when trying to insert the iris unit into the lens barrel from a direction perpendicular to the optical axis, there is a problem that the iris lens unit cannot be inserted due to interference between the zoom lens moving frame and the iris unit. is there.

  The present invention solves the above-described problems, and even in a configuration in which a part of the zoom lens moving frame is housed in the countersink portion of the iris unit in the telephoto state, the iris unit is viewed from the direction perpendicular to the optical axis. Provided is a lens barrel that can be inserted into a cylinder. In addition, an imaging apparatus using the same is provided.

  In order to solve the above problems, a lens barrel of the present invention includes a fixed frame, a contact portion provided on the fixed frame, a moving frame that moves in the optical axis direction within the fixed frame, and the movement A movable portion provided on the frame, and when the moving frame moves in the optical axis direction, the movable portion is in a position where it can contact the contact portion at a first position, It is in a position where it does not abut against the abutment portion.

  As described above, according to the present invention, the first position where the movable part can come into contact with the contact part and the second position where the movable part does not come into contact with the contact part can be taken. Is secured in the lens barrel from a direction perpendicular to the optical axis, and in the second position, a part of the moving frame is housed in a countersink provided in the iris unit. It can be moved to a position. Therefore, it is possible to provide an excellent lens barrel that can be easily assembled while shortening the optical total length.

1 is a perspective view of a lens barrel according to an embodiment of the present invention. 1 is an exploded perspective view of a lens barrel according to an embodiment of the present invention. The perspective view which looked at the lens barrel which concerns on embodiment of this invention from the lower part The figure explaining the attachment method of the iris unit to the lens-barrel which concerns on embodiment of this invention View of zoom lens moving frame viewed from the opposite side of the master flange in step 4 In Step 6, the zoom lens moving frame is viewed from the opposite side of the master flange. Diagram showing the iris unit Sectional drawing of the lens-barrel which concerns on embodiment of this invention Sectional view of lens barrel 100 according to an embodiment of the present invention Sectional drawing of the lens barrel which does not implement this invention in process 7 View of zoom lens moving frame viewed from the opposite side of the master flange Sectional view of the master flange side end face of the main body frame

(Embodiment)
The lens barrel according to the embodiment of the present invention can be mounted on an imaging apparatus such as a video camera or a digital still camera.

  FIG. 1 is a perspective view of a lens barrel 100 according to an embodiment of the present invention. The lens barrel 100 is configured with a master flange 104 as a base. A main body frame 103 is attached to the master flange 104. A fixed lens frame 102 that holds the fixed lens 101 is attached to the main body frame 103. A focus lens moving frame that holds a focus lens that can move in the direction of the optical axis L is housed inside the master flange 104. A zoom lens moving frame that holds a zoom lens that is movable in the direction of the optical axis L is housed inside the main body frame 103. A focus motor 105 for moving the focus lens moving frame is attached to the lower part of the main body frame 103. A zoom motor for moving the zoom lens moving frame is also attached to the lower part of the main body frame 103, but it is in a position where it cannot be seen in FIG. An iris unit 106 is attached to the end of the main body frame 103 on the master flange 104 side.

  FIG. 2 is an exploded perspective view of the lens barrel 100 according to the embodiment of the present invention. A focus guide pole main shaft 107a, a focus guide pole auxiliary shaft 107b, a zoom guide pole main shaft 108a, and a zoom guide pole auxiliary shaft 108b are attached to the master flange 104.

  The focus lens moving frame 109 that holds the focus lens 109d has a hole 109a and a hole 109b for inserting the focus guide pole main shaft 107a and the focus guide pole auxiliary shaft 107b, respectively. The focus lens moving frame 109 can move in the optical axis L direction while being supported by the focus guide pole main shaft 107a and the focus guide pole auxiliary shaft 107b. The focus lens moving frame 109 has a focus rack 109c. The focus rack 109 c meshes with a focus lead screw connected to the focus motor 105. When the focus motor 105 rotates, the focus lead screw rotates. The focus rack 109c moves in the direction of the optical axis L by the rotation of the focus lead screw. In this way, the focus lens moving frame 109 moves in the direction of the optical axis L. By moving the focus lens moving frame 109 in the direction of the optical axis L, the optical image of the subject can be focused on an image sensor (not shown) attached to the opposite side of the master flange 104 from the main body frame 103.

  The zoom lens moving frame 110 that holds the zoom lens 110d has a hole portion 110a and a hole portion 110b for inserting the zoom guide pole main shaft 108a and the zoom guide pole auxiliary shaft 108b, respectively. The zoom lens moving frame 110 can move in the direction of the optical axis L while being supported by the zoom guide pole main shaft 108a and the zoom guide pole auxiliary shaft 108b. The zoom lens moving frame 110 has a zoom rack 110c. The zoom rack 110c meshes with a zoom lead screw connected to a zoom motor. When the zoom motor rotates, the zoom lead screw rotates. The zoom rack 110c moves in the optical axis L direction by the rotation of the zoom lead screw. In this way, the zoom lens moving frame 110 moves in the direction of the optical axis L. By moving the zoom lens moving frame 110 in the direction of the optical axis L, it is possible to enlarge or reduce an optical image of a subject formed on an image sensor (not shown) attached to the opposite side of the master flange 104 from the main body frame 103. .

  FIG. 3 is a perspective view of the lens barrel 100 according to the embodiment of the present invention as viewed from below. The focus motor 105 is fixed to the focus motor fixing bracket 105a. The focus motor fixing bracket 105a rotatably supports the focus lead screw 105b. The focus lead screw 105b is indicated by a dotted line because it is behind the focus motor fixing bracket 105a. The focus motor fixing bracket 105a is fastened to the master flange 104 by screws 105c and 105d.

  The zoom motor 111 is fixed to the zoom motor fixing bracket 111a. The zoom motor fixing bracket 111a rotatably supports the zoom lead screw 111b. Since the zoom lead screw 111b is behind the zoom motor fixing bracket 111a, it is indicated by a dotted line. The zoom motor fixing bracket 111a is fastened to the main body frame 103 by screws 111c and 111d.

  FIG. 4 is a view for explaining a method of attaching the iris unit 106 to the lens barrel 100 according to the embodiment of the present invention. The iris unit 106 is a component that adjusts the amount of light that reaches an image sensor (not shown) that is attached to the opposite side of the master flange 104 from the main body frame 103. The iris unit 106 includes an iris 106a that can mechanically adjust the area of the opening 106d. As the iris motor 106b rotates, the area of the opening 106d of the iris 106a changes. The iris unit 106 is inserted into an iris insertion port 103 a provided at the end of the main body frame 103 on the master flange 104 side. The iris unit 106 is fastened to the main body frame 103 by screws 106e.

  The lens barrel 100 according to the embodiment of the present invention is assembled by using the master flange 104 as a base, attaching the main body frame 103 thereon, and further attaching the fixed lens frame 102 thereon. In the exploded perspective view of the lens barrel 100 according to the embodiment of the present invention shown in FIG. 2, the lens barrel 100 according to the embodiment of the present invention is exploded in the lateral direction and shown in a perspective view. However, for the assembly of the lens barrel 100 according to the embodiment of the present invention, the exploded perspective view of the lens barrel 100 according to the embodiment of the present invention shown in FIG. I want to recall. More specifically, 1) the focus guide pole main shaft 107a, the focus guide pole auxiliary shaft 107b, the zoom guide pole main shaft 108a, and the zoom guide pole auxiliary shaft 108b are attached to the master flange 104 (step 1). 2) The focus guide pole main shaft 107a and the focus guide pole auxiliary shaft 107b are inserted into the focus lens moving frame 109 (step 2). At this time, the focus lens moving frame 109 moves to the master flange 104 side by its own weight. 3) The main body frame 103 is attached to the master flange 104 (step 3). 4) The zoom guide pole main shaft 108a and the zoom guide pole auxiliary shaft 108b are inserted into the zoom lens moving frame 110 (step 4). At this time, the zoom lens moving frame 110 moves to the master flange 104 side by its own weight. 5) The fixed lens frame 102 is attached to the main body frame 103 (step 5). 6) A focus motor 105 and a zoom motor 111 are attached to the master flange 104 and the main body frame 103 (step 6). 7) The iris unit 106 is attached to the main body frame 103 (step 7).

  FIG. 5 is a view of the zoom lens moving frame 110 as viewed from the opposite side of the master flange 104 in Step 4. The zoom rack 110c is biased in the direction toward the optical axis L by the zoom rack spring 110e. Since the zoom rack 110c is behind the zoom lens moving frame 110, a part thereof is indicated by a dotted line. The main body frame 103 is provided with a stopper 103b which is a protrusion at a position where the zoom rack 110c abuts when the zoom rack 110c is urged toward the optical axis L. The zoom lens moving frame 110 moves to the master flange 104 side by its own weight, but stops at a position where the zoom rack 110c contacts the stopper 103b.

  FIG. 6 is a view of the zoom lens moving frame 110 viewed from the opposite side of the master flange 104 in Step 6. However, the fixed lens frame 102 is not shown. Compared to FIG. 5, the zoom rack 110c rotates clockwise against the urging force of the zoom rack spring 110e and meshes with the zoom lead screw 111b. Since the zoom rack 110c is pressed against the zoom lead screw 111b by the biasing force of the zoom rack spring 110e, the engagement of the zoom rack 110c and the zoom lead screw 111b is stable. Since the zoom rack 110c meshes with the zoom lead screw 111b, the zoom lens moving frame 110 does not move in the optical axis L direction unless the zoom lead screw 111b rotates. That is, the zoom lens moving frame 110 does not move toward the master flange 104 due to its own weight. Even if the zoom lens moving frame 110 moves in the direction of the optical axis L by rotating the zoom lead screw 111b, the zoom rack 110c is in a position where it does not come into contact with the stopper 103b.

  FIG. 7 is a diagram showing the iris unit 106. FIG. 7A is a perspective view of the iris unit 106. FIG. 7B is a cross-sectional view showing the BB cross section of the iris unit 106. A counterbore 106c is provided at the periphery of the opening 106d of the iris 106a on the fixed lens frame 102 side.

  FIG. 8 is a cross-sectional view of the lens barrel 100 according to the embodiment of the present invention. Description of the focus guide pole main shaft 107a, the focus guide pole auxiliary shaft 107b, the zoom guide pole main shaft 108a, and the zoom guide pole auxiliary shaft 108b is omitted. The zoom lens moving frame 110 is located at the position most moved to the fixed lens frame 102 side. In a state where the zoom lens moving frame 110 is at the position moved to the most fixed lens frame 102 side, the focal length of the lens barrel 100 according to the embodiment of the present invention is the shortest.

  FIG. 9 is a cross-sectional view of the lens barrel 100 according to the embodiment of the present invention. Description of the focus guide pole main shaft 107a, the focus guide pole auxiliary shaft 107b, the zoom guide pole main shaft 108a, and the zoom guide pole auxiliary shaft 108b is omitted. The zoom lens moving frame 110 is located at the position most moved to the master flange 104 side. In the state where the zoom lens moving frame 110 is at the position where it has moved most to the master flange 104 side, the focal length of the lens barrel 100 according to the embodiment of the present invention is the longest. At this time, a part of the zoom lens moving frame 110 is accommodated in a countersink portion 106 c provided in the iris unit 106. In a state where the focal length of the lens barrel 100 according to the embodiment of the present invention is the longest, that is, in the telephoto state, it is desirable that the zoom lens moving frame 110 be as close as possible to the iris unit 106. This is because there is an effect of shortening the optical total length of the lens barrel 100 according to the embodiment of the present invention. Therefore, the iris unit 106 is provided with a countersink portion 106c.

  FIG. 10 is a cross-sectional view of the lens barrel 100 that does not implement the present invention in step 7. Description of the focus guide pole main shaft 107a, the focus guide pole auxiliary shaft 107b, the zoom guide pole main shaft 108a, and the zoom guide pole auxiliary shaft 108b is omitted. As for actual assembly, recall that the sectional view of the lens barrel 100 which does not implement the present invention in step 7 shown in FIG. 10 is rotated 90 ° clockwise. At this time, the zoom lens moving frame 110 moves to the master flange 104 side by its own weight. Therefore, in step 7, even if the iris unit 106 is to be attached to the main body frame 103, the zoom lens moving frame 110 and the iris unit 106 interfere with each other and the iris unit 106 cannot be attached to the main body frame 103. Since the zoom lens moving frame 110 is designed so that a part of the zoom lens moving frame 110 is accommodated in the countersink portion 106 c provided in the iris unit 106 at the position where the zoom lens moving frame 110 has moved to the master flange 104 side most. The lens moving frame 110 and the iris unit 106 interfere with each other.

  FIG. 11 is a view of the zoom lens moving frame 110 as viewed from the opposite side of the master flange 104. However, the positions C and D that the zoom rack 110c can take are shown. It goes without saying that the zoom rack 110c can take only one position at a time. The zoom rack 110c is biased in a direction toward the optical axis L at a position C by a zoom rack spring 110e (not shown in FIG. 11). The zoom lens moving frame 110 moves to the master flange 104 side by its own weight, but stops at a position where the zoom rack 110c contacts the stopper 103b. The zoom rack 110c meshes with a zoom lead screw 111b (not shown in FIG. 11) at a position D. Since the zoom rack 110c meshes with the zoom lead screw 111b, the zoom lens moving frame 110 does not move in the optical axis L direction unless the zoom lead screw 111b rotates. Thus, since the zoom rack 110c can take two positions C and D, the movement of the zoom lens frame 110 due to its own weight is stopped at the position C where the zoom rack 110c contacts the stopper 103b, and the zoom rack 110c is moved to the stopper 103b. The zoom rack 110c is engaged with the zoom lead screw 111b and moved by restricting the movement to the position D where it does not contact (arrow E). Then, it is possible to secure a space for inserting the iris unit 106 between the zoom lens frame 110 and the master flange 104 side end surface of the main body frame 103. In this way, as shown in FIG. 10, when the iris unit 106 is attached to the main body frame 103, the zoom lens moving frame 110 and the iris unit 106 interfere with each other so that the iris unit 106 cannot be attached to the main body frame 103. The problem can be solved.

  At the position C where the zoom rack 110c comes into contact with the stopper 103b, the movement of the zoom lens frame 110 due to its own weight is stopped, and the zoom rack 110c is moved to the position D where it does not come into contact with the stopper 103b (arrow E). In order to engage with the lead screw 111b, the zoom rack 110c may be moved from a position C where it abuts against the stopper 103b to a position D where it does not abut against the stopper 103b using a jig. When the zoom motor fixing bracket 111a is provided with a pressing portion and the zoom motor fixing bracket 111a integrated with the zoom motor 111 and the zoom lead screw 111b is attached to the main body frame 103, the pressing portion provided on the zoom motor fixing bracket 111a. Thus, the zoom rack 110c may be moved from the position C that contacts the stopper 103b to the position D that does not contact the stopper 103b.

  FIG. 12 is a cross-sectional view of the end face of the main body frame 103 on the master flange 104 side. FIG. 12A shows a state where the zoom rack 110c is at the position C in FIG. FIG. 12B shows a state where the zoom rack 110c is at the position D in FIG. In FIG. 12A, since the zoom rack 110c contacts the stopper 103b, the zoom lens frame 110 cannot move to the master flange 104 side of the main body frame 103 any more. Therefore, the iris unit 106 can be inserted between the zoom lens frame 110 and the master flange 104 side end surface of the main body frame 103. In FIG. 12B, since the zoom rack 110c does not come into contact with the stopper 103b, the zoom lens frame 110 reaches a position where a part of the zoom lens frame 110 is accommodated in a countersink portion 106c provided in the iris unit 106. Can move. In FIG. 12B, the zoom lead screw 111b is not shown.

  The iris unit 106 may be attached to the main body frame 103 after the zoom rack 110c is engaged with the zoom lead screw 111b to restrict movement, or at a position where the zoom rack 110c contacts the stopper 103b. After the movement due to its own weight is stopped, the zoom rack 110c may be engaged with the zoom lead screw 111b before the movement is restricted.

  According to the present invention, it is possible to provide an excellent lens barrel that can be easily assembled while shortening the total optical length, and thus is useful as a lens barrel of an imaging apparatus such as a video camera or a digital still camera.

DESCRIPTION OF SYMBOLS 100 Lens barrel 101 Fixed lens 102 Fixed lens frame 103 Main body frame 103a Stopper 104 Master flange 105 Focus motor 105a Focus motor fixing bracket 105b Focus lead screw 105c Screw 105d Screw 106 Iris unit 106a Iris 106b Iris motor 106c Countersink 106d Opening 106e screw 107a focus guide pole main shaft 107b focus guide pole auxiliary shaft 108a zoom guide pole main shaft 108b zoom guide pole auxiliary shaft 109 focus lens moving frame 109a hole portion 109b hole portion 109c focus rack 109d focus lens 110 zoom lens frame 110a hole portion 110b hole 110c Movable part

Claims (8)

A fixed frame,
A contact portion provided on the fixed frame;
A moving frame that moves in the optical axis direction within the fixed frame;
A movable part provided in the moving frame;
With
When the moving frame moves in the optical axis direction,
The movable part is
In a position where it can contact the contact portion in the first state,
In a position that does not contact the contact portion in the second state,
A lens barrel characterized by that. The movable part is
Urged in a direction from the second state toward the first state,
The lens barrel according to claim 1. Further comprising a restricting means for restricting the movable part to the second state;
The lens barrel according to claim 2. The movable part is
Rack,
The regulating means is
A lead screw,
The lens barrel according to claim 3. It further has a diaphragm means for adjusting the amount of light,
The aperture means is
After the movable part is regulated to the second state by the regulating means, it is inserted into the fixed frame from a direction perpendicular to the optical axis.
The lens barrel according to claim 3. It further has a diaphragm means for adjusting the amount of light,
The aperture means is
When the movable part is in the first state, it is inserted into the fixed frame from a direction perpendicular to the optical axis.
The lens barrel according to claim 3. The aperture means is
In a portion facing the moving frame, it has a recess for storing a part of the moving frame.
The lens barrel according to claim 5 or 6, wherein An imaging apparatus comprising the lens barrel according to claim 1.

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