JP2009139573A - Lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens barrel smoothly moving an optical component along an optical axis by securely reducing resistance caused by a flexible printed board, and to provide an imaging apparatus. <P>SOLUTION: In the lens barrel 2 and imaging apparatus 1, an FPC 32 is attached to a shutter zoom lens unit 12 which moves along the optical axis L2, such that the FPC 32 is bent so as to surround the optical axis L2. This increases the bend radius of the FPC 32 and hence decreases the stiffness of the FPC 32. Accordingly, resistance caused by the FPC 32 is securely reduced and the shutter zoom lens unit 12 can be smoothly moved along the optical axis L2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lens barrel and an imaging device applied to, for example, a camera-equipped mobile phone.

  As a conventional imaging device, a flexible printed circuit board for transmitting an electrical signal is connected to a coil or the like arranged on an optical component (for example, a zoom lens or a focus lens) that moves along the optical axis. Things are known. In such an imaging apparatus, as a technique for reducing the arrangement space of the flexible printed circuit board, a technique is known in which the flexible printed circuit board is bent and the bent excess portion is retracted between the optical component and the housing (for example, , See Patent Document 1). However, in such a technique, a resistance force is applied in a direction against the movement of the optical component by the bent flexible printed circuit board, and the smooth movement of the optical component may be hindered.

As a technique for reducing the resistance generated by such a flexible printed circuit board, a flexible printed circuit board is bent in a direction perpendicular to the optical axis of the optical component (for example, see Patent Document 2), and a guide for guiding the optical component. There exists what wound the flexible printed circuit board to the axis | shaft (for example, refer patent document 3).
Japanese Patent Laid-Open No. 7-110422 JP 2003-75708 A JP 2006-215521 A

  However, in the above-described technology, since the bending radius of the flexible printed circuit board is small, the flexible printed circuit board is strong, and it is difficult to say that the effect of reducing the resistance force generated by the flexible printed circuit board is sufficient.

  Accordingly, the present invention has been made in view of such circumstances, and a lens mirror that can reliably reduce the resistance generated by the flexible printed circuit board and smoothly move the optical component along the optical axis. An object is to provide a cylinder and an imaging device.

  In order to achieve the above object, a lens barrel according to the present invention is bent so as to surround the optical axis, a housing that houses a plurality of lenses, an optical component that moves along the optical axis in the housing, And a flexible printed board having one end connected to the optical component and the other end electrically connected to a control unit that controls the optical component.

  In this lens barrel, a flexible printed board is bent and attached to an optical component that moves along the optical axis so as to surround the optical axis. Thereby, since the bending radius of a flexible printed circuit board becomes large, the strain of a flexible printed circuit board can be weakened. For this reason, it is possible to surely reduce the resistance generated by the flexible printed circuit board and smoothly move the optical component along the optical axis.

  Here, in the lens barrel, the flexible printed circuit board is preferably bent along the periphery of the optical component. By comprising in this way, the bending radius of a flexible printed circuit board can be made still larger, and the limited accommodation space can be used effectively.

  An imaging apparatus according to the present invention includes the lens barrel described above and an imaging element that detects light imaged by the lens.

  According to this imaging apparatus, since the lens barrel described above is provided, it is possible to reliably reduce the resistance force by the flexible printed circuit board and smoothly move the optical component along the optical axis.

  According to the present invention, it is possible to reliably reduce the resistance generated by the flexible printed circuit board and to smoothly move the optical component along the optical axis.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a perspective view of an embodiment of an imaging apparatus according to the present invention. As shown in FIG. 1, the imaging apparatus 1 includes a rectangular parallelepiped lens barrel 2 having a rectangular bottom surface and a height shorter than each side of the bottom surface, and an imaging element 3 such as a CMOS. ing. A bending optical system is applied to the lens barrel 2. Thereby, in the imaging apparatus 1, the light incident from the subject side along the optical axis L <b> 1 parallel to the height direction of the lens barrel 2 (hereinafter simply referred to as “height direction”) is the bottom surface of the lens barrel 2. Is bent by 90 ° by the lens barrel 2 along the optical axis L2 parallel to the longitudinal direction (hereinafter simply referred to as “longitudinal direction”), and is detected by the imaging device 3.

  2 is an exploded perspective view of the imaging apparatus of FIG. 1, and FIG. 3 is an internal configuration diagram of the imaging apparatus of FIG. As shown in FIGS. 2 and 3, the lens barrel 2 includes a box-shaped housing 4. The housing 4 has an opening 5a that opens to the image sensor 3 side in the longitudinal direction, and a main body 5 that is formed with an opening 5b that opens to one side in a direction perpendicular to the longitudinal direction and perpendicular to the height direction. In addition, a lid 6 that covers the opening 5 a of the main body 5 is provided. Each of the main body 5 and the lid 6 is made of, for example, polycarbonate with glass fiber, and is integrally formed by injection molding.

  A light passage hole 5c through which light traveling from the subject side along the optical axis L1 enters the main body portion 5 on the front wall of the main body portion 5 (that is, the wall having the bottom surface on the subject side of the lens barrel 2). A light transmission plate 7 that covers the light passage hole 5 c is attached to the front wall of the main body 5. A lens may be used instead of the light transmission plate 7. In the housing 4, a prism 8 is disposed on the optical axis L1 on the rear side of the light passage hole 5c and bends light incident from the subject side along the optical axis L1 by 90 ° along the optical axis L2. Has been. In the housing 4, a fixed lens 11 positioned on the front side of the image sensor 3 on the optical axis L <b> 2 is disposed. The prism 8 is held by the main body 5, and the fixed lens 11 is held by the lid 6.

  Note that, at the end of the main body 5 opposite to the image sensor 3 in the longitudinal direction, the back wall of the main body 5 (that is, the wall having the bottom surface opposite to the subject of the lens barrel 2) is bent in a crank shape. By forming the notch portion 5d, the thickness is reduced (lower profile) than the other portions of the main body portion 5. As described above, the end of the main body 5 opposite to the image sensor 3 in the longitudinal direction can be thinned because the end of the main body 5 has a thickness of the prism 8 disposed therein. It is enough to consider the minutes.

  Further, in the housing 4, a shutter / zoom lens unit (optical component) 12 positioned on the rear side of the prism 8 on the optical axis L <b> 2, and a shutter / zoom lens unit 12 and a fixed lens 11 on the optical axis L <b> 2. A zoom focus lens unit 13 located between them is disposed.

  The shutter / zoom lens unit 12 includes a shutter that selectively passes and blocks light traveling along the optical axis L2, and a zoom lens. The shutter / zoom lens unit 12 includes a cylindrical engaging portion 12a that engages with a guide shaft 14 provided on the opening 5b side with respect to the optical axis L2 in the housing 4, and an optical axis L2 in the housing 4. On the other hand, it has a U-shaped groove-like engaging portion 12b that engages with a rotation-preventing shaft 15 that is provided upright on the opposite side of the opening 5b. Accordingly, the shutter / zoom lens unit 12 can move along the optical axis L2 in a state where the rotation around the optical axis L2 is restricted.

  The zoom focus lens unit 13 includes a zoom focus lens. The zoom focus lens unit 13 includes a cylindrical engaging portion 13a that engages with a guide shaft 16 that is erected on the side of the opening 5b with respect to the optical axis L2 in the housing 4, and a U that engages with a rotation preventing shaft 15. It has a groove-shaped engaging portion 13b. Thereby, the zoom focus lens unit 13 can move along the optical axis L2 in a state where the rotation around the optical axis L2 is restricted. The guide shaft 14 and the guide shaft 16 are juxtaposed in the height direction.

  A drive unit 17 is disposed in the opening 5 b of the main body 5. FIG. 4 is a perspective view of a drive unit of the imaging apparatus of FIG. As shown in FIG. 4, the drive unit 17 has a support member 18 including a rectangular thin plate-like mounting portion 18 a and rectangular thin plate-like support portions 18 b and 18 c erected at both ends in the longitudinal direction. Yes. The support member 18 is integrally formed by bending a stainless steel thin plate.

  A stepping motor (drive motor) 21 is attached to the outer surface of the support portion 18b. Both ends of the lead screw 22 of the stepping motor 21 are pivotally supported by support portions 18b and 18c, and a driven nut 23 having a convex portion 23a is screwed into a portion between the support portions 18b and 18c of the lead screw 22. Has been. On the other hand, a stepping motor (drive motor) 24 is attached to the outer surface of the support portion 18c. Both ends of the lead screw 25 of the stepping motor 24 are pivotally supported by support portions 18b and 18c, and a driven nut 26 having a convex portion 26a is screwed into a portion between the support portions 18b and 18c of the lead screw 25. Has been. The lead screw 22 and the lead screw 25 are juxtaposed in the standing direction of the support portions 18b and 18c.

  As shown in FIGS. 2 and 3, the drive unit 17 is disposed in the opening 5b of the main body 5 so that the standing direction of the support portions 18b and 18c coincides with the height direction, and the mounting portion 18a. Is attached to the main body 5 by being screwed to the front wall of the main body 5. As described above, in the drive unit 17, the stepping motor 21 and the stepping motor 24 are alternately arranged so that the lead screw 22 and the lead screw 25 are close to each other. As a result, the drive unit 17 contributes to the thinning of the main body 5 and the lens barrel 2.

  The convex portion 23 a of the driven nut 23 screwed into the lead screw 22 is fitted in the concave portion of the engaging portion 12 c of the shutter / zoom lens unit 12. Thereby, when the lead screw 22 is rotated by the stepping motor 21, the shutter / zoom lens unit 12 moves along the optical axis L2. On the other hand, the convex portion 26 a of the driven nut 26 screwed into the lead screw 25 is fitted in the concave portion of the engaging portion 13 c included in the zoom focus lens unit 13. Thus, when the lead screw 25 is rotated by the stepping motor 24, the zoom focus lens unit 13 moves along the optical axis L2.

  A circuit board 27 provided with an image pickup device 3 located on the rear side of the fixed lens 11 on the optical axis L2 on the inner surface is attached to the lid portion 6 of the housing 4. A shutter drive circuit (control unit), a motor drive circuit, and the like are also provided on the inner surface of the circuit board 27, and connector connections for inputting and outputting electrical signals to the circuit board 27 are provided on the outer surface of the circuit board 27. A port 28 is provided. Each of the stepping motors 21 and 24 and the motor drive circuit of the drive unit 17 is a flexible printed circuit board (hereinafter referred to as an outer surface of the side wall facing the opening 5a and the outer surface of the side wall facing the opening 5b in the main body 5). (Referred to as “FPC”) 31. The shutter and the shutter drive circuit of the shutter / zoom lens unit 12 are electrically connected by the FPC 32 extending to the outer surface of the side wall of the main body 5 facing the opening 5b and the FPC 31 electrically connected to the FPC 32. ing.

  FIG. 5 is a perspective view showing the FPC attached to the shutter / zoom lens unit. As shown in FIG. 5, the FPC 32 surrounds the optical axis L2 along the periphery of the shutter / zoom lens unit 12 within a range not exceeding the periphery of the shutter / zoom lens unit 12 when viewed from the optical axis L2 direction. Is bent. That is, the FPC 32 is largely bent so as to surround the movement axis of the shutter / zoom lens unit 12. The end portion 32 b of the FPC 32 is connected to the shutter of the shutter / zoom lens unit 12, while the end portion 32 c of the FPC 32 is fixed to the housing 4 and is provided on the outer surface of the circuit board 27. And are electrically connected. The FPC 32 may be disposed beyond the periphery of the shutter / zoom lens unit 12 as viewed from the direction of the optical axis L2.

  The drive unit 17 disposed in the opening 5b of the main body 5 and the FPC 31 disposed on the outer surface of the side wall facing the opening 5a in the main body 5 are formed by bending a thin plate made of stainless steel into an L shape. It is covered by an integrally formed exterior cover 33. Further, the FPC 31 disposed on the outer surface of the side wall facing the opening 5b in the main body 5 and the circuit board 27 attached to the lid 6 of the housing 4 are formed by bending a thin plate made of stainless steel into an L shape. It is covered with an integrally formed exterior cover 34.

  The exterior cover 33 and the exterior cover 34 are detachably engaged with each other at a corner where the side wall facing the opening 5 a and the side wall facing the opening 5 b intersect in the main body 5. Pinned to the lid portion 6 of the housing 4 at a corner portion sandwiched between the portion 5a and the opening portion 5b. The exterior cover 34 is electrically connected to the ground terminal of the circuit board 27. Further, the exterior covers 33 and 34 are formed on the outer surface of the front wall and the outer surface of the main body 5 by vapor deposition or the like. The metal film is electrically connected. Thereby, each component of the imaging device 1 is covered with the electromagnetic shield. A portion of the exterior cover 34 corresponding to the connector connection port 28 of the circuit board 27 is cut out so that the connector can be accessed with respect to the connector connection port 28.

  As described above, in the lens barrel 2 and the imaging apparatus 1 according to the present embodiment, the FPC 32 is bent and attached to the shutter / zoom lens unit 12 that moves along the optical axis L2 so as to surround the optical axis L2. It has been. Thereby, since the bending radius of FPC32 becomes large, the strain of FPC32 can be weakened. Therefore, the resistance force generated by the FPC 32 can be reliably reduced, and the shutter / zoom lens unit 12 can be smoothly moved along the optical axis L2. As a result, the load on the stepping motor 21 that moves the shutter / zoom lens unit 12 can be reduced.

  Further, according to the lens barrel 2 and the imaging apparatus 1 according to the present embodiment, the FPC 32 is bent along the periphery of the shutter / zoom lens unit 12, thereby further increasing the bending radius of the FPC 32. In addition, the limited storage space can be used effectively.

  The present invention is not limited to the embodiment described above.

  For example, the shutter / zoom lens unit 12 has been described as an example of an optical component, but it may be a rigid component. In short, any component that moves in the optical axis direction may be used.

  Further, in the above-described embodiment, the case where the FPC 32 and the shutter / zoom lens unit 12 are joined is described in the case where the end portion 32b of the FPC 32 is directly connected to the shutter / zoom lens unit 12. In short, it is only necessary to be connected so as to interlock with the moving member.

  In the above embodiment, the FPC 32 is attached so as to make one rotation along the periphery of the shutter / zoom lens unit 12, but even if it is attached in a spiral shape so as to surround the optical axis, Since the bending radius is increased, it is possible to reliably reduce the resistance generated by the FPC 32 and reduce the load on the stepping motor 21 that moves the shutter / zoom lens unit 12.

  The lens barrel 2 is not limited to the one to which the bending optical system is applied, and may be one to which a retractable optical system or the like is applied.

It is a perspective view of one embodiment of an imaging device concerning the present invention. It is a disassembled perspective view of the imaging device of FIG. It is an internal block diagram of the imaging device of FIG. It is a perspective view of the drive unit of the imaging device of FIG. FIG. 2 is a perspective view of a shutter / zoom lens unit and a flexible printed circuit board of the imaging apparatus of FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Imaging device, 2 ... Lens barrel, 3 ... Imaging element, 4 ... Housing, 11 ... Fixed lens, 12 ... Shutter zoom lens unit, 13 ... Zoom focus lens unit, 21, 24 ... Stepping motor (drive motor) 32: Flexible printed circuit board.

Claims (3)

A housing that houses a plurality of lenses;
An optical component that moves along an optical axis in the housing;
A flexible printed circuit board that is bent so as to surround the optical axis, one end of which is connected to the optical component, and the other end of which is electrically connected to a control unit that controls the optical component;
A lens barrel comprising:   The lens barrel according to claim 1, wherein the flexible printed circuit board is bent along the periphery of the optical component. The lens barrel according to claim 1 or 2,
An image sensor for detecting light imaged by the lens;
An imaging apparatus comprising:

Images