JP2008250203A - Lens barrel and photographing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel which is shortened further, so that a body can be thinned further, and to provide a photographing apparatus in which the lens barrel is incorporated, so that thin structure is achieved. <P>SOLUTION: An engaging groove K1 extending in a circulating direction is provided near the rear end of the outer circumferential surface of an intermediate barrel 111A. An engaging projection 1141A is provided on a straight advance key ring 114A, wherein the engaging projection 1141A relatively rotatably engages the straight advance key ring 114A to the intermediate barrel 111A, by making the engaging projection 1141A go on the outer circumferential surface of the intermediate barrel from the rear side of the intermediate barrel and then by fitting it in the engaging groove K1 on the outer circumferential surface of the intermediate barrel. By making the engaging projection 1141A of the straight advance key ring go on the outer circumferential surface of the intermediate barrel 111A from the rear side of the intermediate barrel and by engaging it in the engaging groove K1 on the outer circumferential surface of the intermediate barrel, the intermediate barrel 111A is made shorter in length than before. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens barrel that can be extended and retracted, and that holds a zoom lens composed of a plurality of lens groups, and an imaging apparatus including the lens barrel.

  Recently, the body of an imaging device has been actively reduced in size and thickness, and in the body of an imaging device equipped with a lens barrel that can be extended and retracted and holds a zoom lens composed of a plurality of lens groups. There is a growing demand for further miniaturization and thickness reduction.

  FIG. 1 is a diagram showing a configuration of a lens barrel of a zoom lens that is incorporated in the body of a photographing apparatus having a small and thin structure.

  FIG. 1 (a) shows the configuration of a lens barrel that is provided with a three-group zoom lens and that can be extended and retracted. FIG. 1 (b) shows a dotted line in FIG. 1 (a). An enlarged view of the circled part is shown. In the example of FIG. 1, the first lens group 101 and the second lens group 102 of the three-group zoom lens function as a variable focal length lens, and the third lens group 103 functions as a focus lens.

  In FIG. 1, the front moving cylinder 110 and the second lens group are moved by moving the front moving cylinder 110 and the second lens group holding frame 115 by providing the intermediate cylinder 111 and rotating the intermediate cylinder 111 by the drive cylinder 113. The lens barrel 100 can be shortened by reducing the number of parts required to move the holding frame 115, and a front moving cylinder that holds the first lens group 101 using a linear key ring 114 as disclosed in Patent Document 1. A structure is shown in which the rotation of the second lens group holding frame 115 that holds 110 and the second lens group 102 is restricted so that the optical axes of the lens groups having variable focal lengths can be easily aligned. FIG. 1 shows a fixed cylinder 112 having a cam groove HL through which the cam pin CP of the intermediate cylinder 111 passes and a rectilinear key groove KEY2 that extends in the optical axis direction and engages with the rectilinear key ring 114.

  Here, when the lens barrel 100 of FIG. 1 is incorporated into the body of a photographing apparatus having a thin structure, the front moving cylinder 110 holding the first lens group 101 is moved from the retracted position to the extended end, The function of the intermediate cylinder 111 that moves the second lens group 102 to the wide end or the tele end according to the operation of the illustrated zoom switch will be described.

  FIG. 2 is a development view of a cam groove provided on the inner surface of the intermediate cylinder 111.

  As shown in FIG. 2, the inner surface of the intermediate cylinder 111 has a predetermined distance between the cam groove A that engages the cam pin of the front moving cylinder 110 and the cam groove B that engages the cam pin of the second lens group holding frame 115. It is provided at three places apart.

  For example, when the power switch is operated when the lens barrel 100 of FIG. 1 is incorporated in the body inside the photographing apparatus and the lens barrel 100 is in the retracted state, the drive cylinder 113 rotates and receives the rotation to be intermediate. As the cylinder 111 rotates, the intermediate cylinder 111 moves along the cam groove A on the inner surface of the intermediate cylinder 111 to the supply end W2 while the intermediate cylinder 111 moves in the optical axis direction. In this example, the second lens group holding frame 115 that holds the second lens group 102 at this time is positioned along the cam groove B at the wide end W1. Here, when a zoom switch (not shown) is operated to the tele side, the intermediate cylinder 111 rotates, the front moving cylinder 110 moves along the cam groove A in the tele end T2 direction, and the lens holding frame 115 moves along the cam groove B. Starts to move toward the telephoto end T1. When the zoom switch continues to be operated, the front moving cylinder 110 moves along the cam groove A to the tele end T2, and the second lens group holding frame 115 also moves to the tele end T1, and the zoom lens has the maximum magnification. Become telephoto. Thereafter, when the zoom switch is operated to the wide side, the intermediate cylinder 111 rotates in the reverse direction, the front moving cylinder 110 moves along the cam groove A in the feeding end W2 direction, and the lens holding frame 115 moves in the wide end W1 direction. start. If the zoom switch is continuously operated to the wide side, the front moving cylinder 110 moves to the feeding end W2, which is also the wide end, and the second lens group holding frame 115 also moves to the wide end W1, and this zoom lens has a minimum magnification. Become a wide angle.

  When the power switch is further turned off, the second lens group holding frame 115 that holds the second lens group 102 moves to the retracted position P1 along the cam groove B in FIG. 2 and moves forward to hold the first lens group 101. The cylinder 110 moves to the retracted position P2 so that the first lens group 101 and the second lens group 102 are brought close to each other, and the front moving cylinder 110 and the intermediate cylinder 111 are retracted into the drive cylinder 113 and the fixed cylinder 112.

  The lens barrel 100 that has been shortened by providing the intermediate cylinder 111 in this manner is incorporated into the body having a thin structure.

However, in the configuration of this example, in order to hold the rectilinear key ring 114 on the intermediate cylinder 111 so as to be relatively rotatable, a cam groove is formed on the inner peripheral surface of the intermediate cylinder 111 as shown by a one-dot chain line in FIGS. It is necessary to provide an engagement groove K in addition to A and B. For this reason, the length in the optical axis direction of the intermediate cylinder 111 is inevitably increased by the amount that the engagement groove K must be provided. If the lens barrel cannot be shortened by shortening the length of the intermediate tube 111, it cannot cope with further thinning of the body of the photographing apparatus.
JP 2005-275351 A

  The present invention solves the above-mentioned problems, and further shortens the lens barrel that can be incorporated into a thin body, and a photographing apparatus in which the lens barrel is incorporated to achieve a thin structure. Is intended to provide.

The lens barrel of the present invention that achieves the above-described object is a lens barrel that can be extended and retracted, holding a zoom lens composed of a plurality of lens groups.
An intermediate cylinder having a cam groove for feeding a lens group on the inner peripheral surface and having an outwardly projecting cam pin on the outer peripheral surface and moving in the optical axis direction while being rotated by receiving a driving force from the cam pin ,
Straight movement that is arranged inside the intermediate cylinder and engages with the intermediate cylinder so as to be rotatable relative to the intermediate cylinder, and moves in the optical axis direction without rotation as the intermediate cylinder moves in the optical axis direction. With a key ring,
The intermediate cylinder has an engaging groove extending in the circumferential direction near the rear end of the outer peripheral surface of the intermediate cylinder,
Engagement protrusions that engage the rectilinear key ring relative to the intermediate cylinder so that the rectilinear key ring turns from the rear side of the intermediate cylinder to the outer peripheral surface of the intermediate cylinder and fits into the engaging groove on the outer peripheral surface of the intermediate cylinder. It is characterized by having.

  In the lens barrel of the present invention, an engagement groove is provided in the circumferential direction in the vicinity of the rear end of the outer peripheral surface of the intermediate cylinder, an engagement protrusion is provided in the linear key ring, and the engagement protrusion is provided from the rear side of the intermediate cylinder. The length of the intermediate cylinder can be shortened by engaging the rectilinear key ring with the intermediate cylinder so as to be rotatable relative to the intermediate cylinder by turning around the outer peripheral surface of the intermediate cylinder and fitting into the engaging groove on the outer peripheral surface of the intermediate cylinder. If the length of the intermediate cylinder is shortened as described above, the lens barrel can be shortened, and can be incorporated in the body of a photographing apparatus having a thin structure.

  Here, it is preferable that the cam groove provided on the inner peripheral surface of the intermediate cylinder extends to a position where the engagement groove formed on the outer peripheral surface of the intermediate cylinder overlaps with the thickness direction of the intermediate cylinder.

  Then, the inner and outer peripheral surfaces of the intermediate cylinder can be used efficiently, and the length of the intermediate cylinder can be further shortened.

The lens barrel further includes
The first lens group constituting the zoom lens is held and engaged with the linear key ring and engaged with the cam groove on the inner peripheral surface of the intermediate cylinder, and without rotation as the intermediate cylinder rotates. A front moving cylinder that moves in the direction of the optical axis;
The second lens group constituting the zoom lens is held and engaged with the linear key ring and engaged with the cam groove on the inner peripheral surface of the intermediate cylinder, and without rotation as the intermediate cylinder rotates. A second lens group holding frame that moves in the optical axis direction;
A fixed cylinder having a cam groove through which the cam pin of the intermediate cylinder passes, and a key groove extending in the optical axis direction and engaged with the linear key ring;
A key groove extending in the optical axis direction that engages with a tip portion of the intermediate cylinder cam pin that passes through the cam groove of the fixed cylinder, is located outside the fixed cylinder, and is used for driving force from the zoom motor. It is preferable that it is an aspect provided with a drive cylinder that receives and rotates without moving in the optical axis direction to drive the intermediate cylinder.

  For example, when the present invention is applied to the lens barrel shown in FIGS. 1 and 2 having the above-described configuration, it is not necessary to provide the engagement groove K shown in FIG. 2 on the inner peripheral surface of the intermediate cylinder. Shortening is achieved, and as a result, the entire lens barrel is shortened.

  In addition, an imaging device of the present invention that achieves the above-described object includes the lens barrel of the present invention and an imaging device that captures subject light incident through the lens barrel and generates an image signal. Features.

  Then, it becomes possible to further reduce the thickness of the body of the photographing apparatus by using the lens barrel of the present invention that has been shortened.

  As described above, there is provided a lens barrel that can be incorporated into a thin body by further shortening the lens barrel, and a photographing apparatus in which the lens barrel is incorporated to achieve a thin structure. Realize.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 3 is an exploded view of the lens barrel 100A showing the embodiment of the present invention.

  The configuration of the lens barrel 100A in FIG. 3 is substantially the same as the configuration in FIG. 1, and therefore members having the same functions as those in FIG. However, in this embodiment, in order to make the length of the intermediate cylinder shorter, the configuration of the conventional intermediate cylinder 111 is changed to the configuration of the intermediate cylinder 111A of FIG. 3, and the configuration of the conventional linear key ring 114 is changed to FIG. The configuration is changed to the configuration of the straight key ring 114A.

  The configuration of the lens barrel will be described with reference to FIG.

  A drive cylinder 113 is provided on the outermost wall as shown in the upper left portion of FIG. The drive cylinder 113 is provided with a keyway KEY that engages with a cam pin CP of an intermediate cylinder 111A described later along the optical axis direction on the inner peripheral surface. Further, a fixed cylinder 112 accommodated in the drive cylinder 113 is provided on the right side of the drive cylinder 113, and the fixed cylinder 112 is provided with a through hole HL through which the cam pin CP of the intermediate cylinder 111A passes obliquely. Yes. For this reason, the tip of the cam pin CP of the intermediate cylinder passes through the through hole HL of the fixed cylinder 112 and reaches the key groove of the drive cylinder 113, and the intermediate cylinder 111A is inclined with respect to the fixed cylinder 112 by the rotation of the drive cylinder 113. It will rotate along the through hole HL. In addition, a keyway KEY2 is provided on the inner periphery of the fixed cylinder 112 to engage with a later-described straight key ring 114A.

  Further, a mounting frame 104 for holding the fixed cylinder 112 is provided on the right side. The mounting frame 104 is provided with a motor mounting portion for mounting the zoom motor ZM. Further, two guide rods G1 and G2 are attached to the attachment frame 104 along the optical axis, and a focus lens holding 103A frame for holding the focus lens 103 is attached to the guide rods G1 and G2 so as to be movable. It is like that.

  Further, a feed screw SR for moving the focus lens 103 in the optical axis direction through the mounting frame 104 in FIG. 3 is attached to extend from the support portion 105 supporting the image sensor 1051 to the front of the optical axis. Yes.

  In the lower part of FIG. 3, a front moving cylinder 110 and an intermediate cylinder 111A incorporated inside the fixed cylinder 112 are shown. In the front moving cylinder 110, a holding member for holding the first lens group 101 and its holding member are shown. A member for attaching the holding member to the front moving cylinder 110 is incorporated. Further, on the outer periphery of the front moving cylinder 110, three cam pins CP1 that engage with the cam groove A of the intermediate cylinder 111A are provided at equal intervals with a predetermined distance. Further, the second lens group holding frame 115 is shown on the right side of FIG. 3, and the second lens group holding frame 115 is incorporated inside the intermediate cylinder, and the cam pin CP2 of the second lens group holding frame 115 is provided. It is configured to engage with the cam groove B1 of the intermediate cylinder.

  Cam grooves A and B1 that engage with the cam pins CP1 and CP2 are formed on the inner peripheral surface of the intermediate cylinder 111A, and the outer periphery of the intermediate cylinder 111A penetrates the cam groove HL of the fixed cylinder 112. A cam pin CP that engages with the straight keyway KEY of the drive cylinder 113 is attached. In addition, all the cam pins described in this specification are configured to be attached at equal intervals with a predetermined interval. Further, an engagement groove K1 that engages the linear key ring 114A in a relatively rotatable manner is provided behind the outer peripheral surface of the intermediate cylinder 111A.

  Conventionally, since the engagement groove K (see FIG. 2) is provided on the inner peripheral surface of the intermediate tube 111 (see FIG. 2), the length of the intermediate tube 111 becomes long, and the lens barrel is further shortened. I couldn't do it.

  Therefore, in the present embodiment, the engagement groove K1 is provided in the circumferential direction of the outer peripheral surface of the intermediate cylinder 111A, and the engagement protrusion 1141A that goes around the rear end of the intermediate cylinder 111A and engages with the engagement groove K1 is provided. The linear key ring 114A is provided.

  With this configuration, it is not necessary to provide the engaging groove K1 on the inner peripheral surface of the intermediate cylinder 111A, so that the length of the intermediate cylinder 111A can be made shorter than before.

  Here, the state after the lens barrel shown in the exploded view of FIG. 3 is assembled and incorporated in the photographing apparatus will be described with reference to FIG.

  FIG. 4 is a side view of a cut surface of the lens barrel after the lens barrel shown in the exploded view of FIG.

  FIG. 4A shows the assembled lens barrel 100A as viewed from the front, and the lens barrel 100A is cut by cutting along a plane including the zoom motor ZM and guide rods G1 and G2 for guiding the focus lens FM. FIG. 4B is a side view of the cut surface, and FIG. 4B shows the cut surface cut from the side including the feed screw SC that moves the focus lens FM and the focus motor FM. FIG. 4 (c) shows a side view of the cut and cut surfaces that do not include both the zoom motor ZM and the focus motor FM.

  4A, 4B, and 4C, the second lens held by the first lens group 101 and the second lens group lens holding frame 115 held by the front moving cylinder 110, respectively. When both the group 102 and the telephoto end are in the telephoto position, and the first lens group 101 held by the front moving cylinder 110 and the second lens held by the second lens group lens holding frame 115 There are three states: when the group 102 is at the wide end and at a wide angle, and when the front moving cylinder 110 and the intermediate cylinder 111 are both housed in the fixed cylinder 112 and retracted in the body. It is shown.

  As shown in FIG. 4, the second lens group 102 is largely moved by the rotation of the intermediate cylinder 111A to adjust the focal length.

  Here, the operation of the lens barrel 110A of the present embodiment will be described with reference to FIGS.

  5 and 6 are views for explaining the operation of the lens barrel of the present embodiment.

  FIG. 5A shows a cross section of the lens barrel in the retracted state shown at the bottom of FIG. 4A, and FIG. 5B shows the intermediate cylinder 111A and the rectilinear key ring 114. The relationship is shown. FIG. 6 is a development view of the cam grooves A and B1 formed on the inner peripheral surface of the intermediate cylinder 111.

  As shown in FIGS. 5 and 6, an engagement groove K1 is provided on the outer peripheral surface of the intermediate cylinder 111A, and an engagement protrusion 1141A that engages with the engagement groove K1 is provided on the rectilinear key ring 114. As shown in FIG. 5, when the engagement protrusion 1141A provided on the rectilinear key ring 114A wraps around and engages with the engagement groove K1 provided on the outer peripheral surface of the intermediate cylinder 111 as shown in FIG. As shown in FIG. 6, the cam groove B1 can be extended to the end of the intermediate cylinder 111A.

  As a result, it is no longer necessary to provide the engagement groove K1 on the inner peripheral surface of the intermediate cylinder 111A, and the cam groove can be extended to the end of the intermediate cylinder 111A. It becomes possible to shorten the length.

  When the engagement protrusion 1141A that engages with the outer peripheral surface of the intermediate cylinder 111 is provided on the rectilinear key ring 114A, the rectilinear key ring 114A without changing the length of the rectilinear key ring 114A in the optical axis direction as shown in FIG. Since the engagement protrusion 1141A may be provided so that the tip of the key portion is bent toward the intermediate cylinder 111A, the dimension of the linear key ring 114A in the optical axis direction is the same or never longer even if it is shortened. Never become.

  For this reason, it is possible to shorten the lens barrel by shortening the intermediate cylinder, and it is possible to incorporate the lens barrel in a photographing apparatus having a thinner structure.

  That is, it is possible to further reduce the length of the lens barrel, and to realize a lens barrel that enables the body to be further thinned, and an imaging device in which the lens barrel is incorporated to achieve a thin structure.

It is a figure which shows the structure of the conventional lens barrel incorporated in the body of an imaging device. It is an expanded view of the cam groove provided in the inner surface of the intermediate cylinder. It is an exploded view of a lens barrel showing an embodiment of the present invention. It is sectional drawing which looked at the surface which cut | disconnected and cut | disconnected the lens barrel after assembling the lens barrel shown by the exploded view of FIG. 3 from the horizontal direction. It is a figure explaining the effect | action of the lens barrel of this embodiment. It is a figure explaining the effect | action of the lens barrel of this embodiment.

Explanation of symbols

100, 100A Lens barrel 101 First lens group 102 Second lens group 103 Third lens group (focus lens)
110 Front moving cylinder CP1 Cam pin 111, 111A Intermediate cylinder CP Cam pin 112 Fixed cylinder 113 Drive cylinder 114, 114A Linear key ring 115 Second lens group holding frame CP2 Cam pins K, K1 Engaging grooves A Cam grooves B, B1 Cam grooves W1 Second Wide end of lens group holding frame T1 Tele end of second lens group holding frame W2 Extending end (wide end) of front moving cylinder
T2 Tele end of the front moving cylinder

Claims (4)

In a lens barrel that holds a zoom lens composed of a plurality of lens groups and can be extended and retracted freely.
An intermediate cylinder having a cam groove for feeding a lens group on the inner peripheral surface and having a cam pin projecting outward on the outer peripheral surface and moving in the optical axis direction while being rotated by receiving a driving force from the cam pin; ,
It is arranged inside the intermediate cylinder and engages with the intermediate cylinder so as to be rotatable relative to the intermediate cylinder, and moves in the optical axis direction without rotation as the intermediate cylinder moves in the optical axis direction. With a straight key ring,
The intermediate cylinder has an engaging groove extending in the circumferential direction in the vicinity of the rear end of the outer peripheral surface of the intermediate cylinder,
The rectilinear key ring wraps around the outer peripheral surface of the intermediate cylinder from the rear side of the intermediate cylinder and fits into the engaging groove of the outer peripheral surface of the intermediate cylinder, thereby engaging the rectilinear key ring with the intermediate cylinder in a relatively rotatable manner. A lens barrel having an engaging protrusion.   2. The cam groove provided on the inner peripheral surface of the intermediate cylinder extends to a position where the engagement groove formed on the outer peripheral surface of the intermediate cylinder overlaps with the thickness direction of the intermediate cylinder. The lens barrel described. The lens barrel further includes
The first lens group constituting the zoom lens is held and engaged with the linear key ring and engaged with the cam groove on the inner peripheral surface of the intermediate cylinder, and without rotation as the intermediate cylinder rotates. A front moving cylinder that moves in the direction of the optical axis;
The second lens group constituting the zoom lens is held and engaged with the linear key ring and engaged with the cam groove on the inner peripheral surface of the intermediate cylinder, and without rotation as the intermediate cylinder rotates. A second lens group holding frame that moves in the optical axis direction;
A fixed cylinder having a cam groove through which the cam pin of the intermediate cylinder passes, and a key groove extending in the optical axis direction and engaged with the linear key ring;
A key groove extending in the optical axis direction that engages with a tip portion of the cam pin of the intermediate cylinder, which is located outside the fixed cylinder and engages with the cam groove of the fixed cylinder, and has a driving force from the zoom motor. The lens barrel according to claim 1, further comprising: a drive cylinder that receives and rotates without moving in the optical axis direction to drive the intermediate cylinder.   An imaging apparatus comprising: the lens barrel according to claim 1; and an image pickup device that captures subject light incident through the lens barrel and generates an image signal.

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