JP2012128348A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel capable of preventing FPC from bending with small space at low cost and capable of suppressing generation of ghosts.SOLUTION: A lens barrel includes a second group barrel 32, a basis 44, a second group FPC 48 and a barrel FPC 50. The second group FPC 48 which supplies electric power to a shutter mechanism and a diaphragm mechanism of the second group barrel 32 is attached to the outer periphery of the lens barrel along a basis wall part 44b of the basis 44 after being extracted from the second group barrel 32, bent and drawn outside. A seat 51 is fixed by being nipped between the second group FPC 48 and the basis wall part 44b of the basis 44, and exerts force in a direction to straighten a bent part by contacting the bent part of the second group FPC 48.

Description

  The present invention relates to a lens barrel that is mounted on a photographing apparatus and includes a plurality of lenses, and relates to a lens barrel that can suppress generation of ghosts due to reflection of light rays inside the lens barrel.

  2. Description of the Related Art Conventionally, in a lens barrel mounted on an imaging apparatus such as a digital camera, a flexible printed circuit board (in order to supply power to a unit that is configured to be movable in the optical axis direction inside the lens barrel and includes electronic components) Hereinafter, it is referred to as FPC).

  In order to reduce the thickness of the imaging device, the lens barrel generally has the following configuration. That is, the lens barrel is arranged at a predetermined position when in use (hereinafter referred to as the extended state), and the distance between the lenses is shortened when not in use (hereinafter referred to as the retracted state). It is configured to be housed inside the imaging device.

  The lens barrel is composed of a plurality of cylindrical members arranged concentrically with respect to the optical axis, but the FPC that supplies power to the unit inside the lens barrel is wired closer to the optical axis than each cylindrical member Often done. Therefore, depending on the angle of the incident light beam into the lens barrel, the incident light beam hits and is reflected by the FPC, and a ghost may be generated due to the influence of the reflected light beam from the FPC.

  Therefore, conventionally, the influence of the reflected light beam from the FPC has been reduced by making the surface that the incident light beam hits inside the lens barrel black. However, it was not always effective.

  Further, when the FPC is bent inside the lens barrel and approaches the optical axis direction, the incident light beam into the lens barrel easily hits the bent portion of the FPC, so that a ghost is likely to occur. That is, the reflected light from the FPC is more likely to reach the image sensor inside the lens barrel due to the bending of the FPC, and the ghost intensity is sometimes increased.

  Therefore, as a measure for suppressing the phenomenon in which ghost is generated by a reflected light beam from the FPC, a configuration in which a tension is always applied to the FPC in the optical axis direction using a pulley and a spring has been proposed (for example, for example). , See Patent Document 1). In addition, a plate spring is disposed on the end surface of the cylindrical member that is moved between the retracted state and the extended state in the lens barrel, and the FPC is bent by urging the folded portion of the FPC in the optical axis direction by the plate spring. The structure which takes is proposed (for example, refer patent document 2).

  Here, generation of a ghost due to light reflection from the second group FPC wired inside the conventional lens barrel will be described.

  FIG. 7 is a central sectional view showing a bent state of the second group FPC of the lens barrel according to the conventional example.

  FIG. 7 shows a state in which the second group barrel 232 is extended most toward the subject (upward in the figure). For convenience, the optical axis direction is arranged in a direction different from FIG. Only one side is shown. Further, a cross section passing through the second group FPC 248 is represented by a cross section different from that of FIG.

  The second group FPC 248 extends from the second group lens barrel 232 along the rectilinear cylinder 249 toward the image sensor 224, is bent at the rear end of the rectilinear cylinder 249, and has an opening 247a of the fixed cylinder 247, a slit 246d of the drive ring 246, It passes through the opening 244a of the base 244 and reaches the outside. Further, the second group FPC 248 is bent and fixed by the wall portion 244 b on the side surface of the base 244. The second group FPC 248 is made of a thin resin sheet having elasticity, and is bent in a direction approaching the optical axis by drawing an arc at the bent portion of the rear end of the straight cylinder 49.

  Since the first group barrel 231 and the second group barrel 232 are close to each other in the optical axis direction as shown in the drawing, external light is incident on the inside of the lens barrel at various angles. When a part of the incident light ray hits a bent portion of the second group FPC 248 as indicated by a broken line arrow and the reflected light beam passes through the third lens group 223 and reaches the image sensor 224, it appears as a ghost on the photographing screen due to the influence of the reflected light beam. There is.

  In order to prevent this, it is desirable to further pull the second group FPC 248 and eliminate the bent portion. However, if the second group FPC 248 is pulled too much, the second group FPC 248 is damaged or the second group lens barrel 232 is pulled and tilted. And other harmful effects occur. Therefore, it is inevitable that some bending remains in the second group FPC 248.

Japanese Patent Registration No. 2612946 JP 2002-156575 A

  The lens barrels disclosed in Patent Document 1 and Patent Document 2 described above need to be newly provided with components such as a pulley, a spring, and a leaf spring in order to take the FPC flexure. However, a large amount of space is required in the lens barrel for arranging the components including the components newly provided in the existing components. For this reason, it is desired that the FPC bend at low cost without increasing the number of parts without providing a large space inside the lens barrel.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens barrel that can bend the FPC in a small space and at a low cost and can suppress the occurrence of ghost.

  In order to achieve the above object, the present invention provides a lens barrel that includes a movable lens barrel that can move in the optical axis direction while holding a lens, and a base that has an opening. A power supply member extending from the base through the opening of the base and pulled out of the lens barrel and fixed to the base and supplying power to the movable lens barrel; and the power supply in the base An elastic member that is arranged along a member arrangement location and has elasticity in a direction in which the bending portion of the power supply member in the opening of the base comes into contact with and extends the bending portion.

  According to the present invention, the elastic member having elasticity in the direction of extending the bent portion by contacting the bent portion of the power supply member in the opening of the base is disposed along the position of the power supply member on the base. Thereby, it becomes possible to take the bending of the power feeding member in a small space and at a low cost. As a result, it is possible to suppress the incident light beam to the lens barrel from being reflected by the power supply member and reaching the imaging element of the lens barrel, and thus it is possible to suppress the occurrence of ghost.

It is a front view which shows the structure inside the imaging device which concerns on the 1st Embodiment of this invention. It is a center sectional view showing the composition of a lens barrel. It is a center sectional view showing the state of taking the configuration of the lens barrel and the deflection of the second group FPC. It is a perspective view which shows the attachment structure of 2 group FPC of a lens-barrel. It is a center sectional view showing the state of the 2nd group FPC when the lens barrel is retracted. It is a figure which shows the attachment structure of 2 group FPC of the lens-barrel which concerns on the 2nd Embodiment of this invention. It is a center sectional view showing the bending state of 2nd group FPC of the lens barrel concerning a conventional example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a front view showing an internal configuration of the imaging apparatus according to the first embodiment of the present invention.

  In FIG. 1, the imaging device includes a battery box 2, a strobe light emitting unit 3, a condenser 4, a tripod seat 5, a lens barrel 10, a zoom driving unit 11, a focus driving unit 12, an optical viewfinder unit 13, an imaging device substrate (not shown). ) Is configured as a digital camera. Note that the broken line indicated by reference numeral 1 represents the outer shape of the imaging apparatus main body.

  The battery box 2 holds a battery (not shown). A tripod seat 5 is formed integrally with the battery box 2. The capacitor 4 supplies power to the strobe light emitting unit 3. The lens barrel 10 is attached to the imaging apparatus body and inputs an image of a subject. The zoom drive unit 11 performs a zoom operation of the lens barrel 10. The focus driving unit 12 performs a focusing operation of the lens barrel 10. The optical finder unit 13 is used for confirmation of a subject. An electronic circuit that controls the imaging device is mounted on the imaging device substrate.

  FIG. 2 is a central sectional view showing the configuration of the lens barrel.

  In FIG. 2, the lens barrel is represented by a cross section passing through the optical axis 14 of the lens. The lens barrel includes a first group lens 21, a second group lens 22, a third group lens 23, an image sensor 24, a first group barrel 31, a second group barrel 32, a lens holder 43, a moving cam ring 45, a drive ring 46, and a fixed lens barrel. A cylinder 47 and a rectilinear cylinder 49 are provided. Further, the lens barrel includes a flexible printed circuit board 48 (hereinafter referred to as a second group FPC 48) and a flexible printed circuit board 50 (hereinafter referred to as a lens barrel FPC 50).

  The optical system of the lens barrel of the present embodiment is configured as an optical system in which the focal length changes depending on the arrangement of the first group lens 21 and the second group lens 22, and the focal point changes depending on the arrangement of the third group lens 23. However, it is not limited to this.

  The first group lens barrel 31 includes a first group lens 21 and a lens holder 41 that holds the first group lens 21, and a lens barrier that protects the first group lens 21, although the description is omitted. The second group barrel 32 (movable barrel) includes a second group lens 22 and a lens holder 42 that holds the second group lens 22. Although not described, the lens holder 42 includes a shutter mechanism and a diaphragm mechanism.

  A cam follower pin (not shown) having a taper is provided on the outer periphery of each of the first group barrel 31 and the second group barrel 32. In addition, cam grooves 45 a and 45 b having a tapered cross section are provided on the inner peripheral portion of the movable cam ring 45. The first group lens barrel 31 and the second group lens barrel 32 are held by the moving cam ring 45 by cam-fitting cam follower pins to the cam grooves 45a and 45b of the moving cam ring 45, respectively.

  The rectilinear barrel 49 is a member that restricts the rotation of the first group barrel 31 and the second group barrel 32 and is rotatably held by the movable cam ring 45. Further, the rotation of the rectilinear cylinder 49 is restricted by a rectilinear groove (not shown) provided in the inner peripheral portion of the fixed cylinder 47.

  A cam follower pin 45 d having a taper is provided on the outer peripheral portion of the moving cam ring 45. Further, a cam groove 47 a having a tapered cross section is provided on the inner peripheral portion of the fixed cylinder 47. The moving cam ring 45 is held by the fixed cylinder 47 when the cam follower pin 45 d is cam-fitted into the cam groove 47 a of the fixed cylinder 47.

  A rectilinear groove 46 e is provided on the inner peripheral portion of the drive ring 46. A drive pin 45 c is provided on the outer periphery of the movable cam ring 45. When the drive pin 45 c of the moving cam ring 45 is fitted into the rectilinear groove 46 e of the drive ring 46, the rotation of the drive ring 46 is transmitted to the moving cam ring 45.

  The drive ring 46 is slidably and rotatably held on the outer peripheral side of the fixed cylinder 47 and can freely rotate around the optical axis, but movement in the optical axis direction is restricted by the fixed cylinder 47. ing. Although not described in detail, the drive ring 46 is rotated around the optical axis by the zoom drive unit 11 (see FIG. 1).

  The base 44 is a member that serves as a base for the fixed cylinder 47, and holds the imaging element 24 such as a CCD and the optical viewfinder unit 13 in addition to holding the fixed cylinder 47. As will be described later, the base 44 is provided with an opening 44a capable of allowing deformation of the sheet 51 and a base wall 44b along which the sheet 51 is placed (see FIG. 3). The lens holder 43 is a member that holds the third group lens 23 and is freely moved in the optical axis direction by the focus driving unit 12 although the description is omitted.

  The second group FPC 48 is a power supply member for supplying power to the shutter mechanism and the diaphragm mechanism included in the lens holder 42 of the second group barrel 32. The second group FPC 48 extends from the second group lens barrel 32, is bent inside the lens barrel, is pulled out of the lens barrel through the opening 44a of the base 44, and a base wall portion 44b (arrangement location) of the base 44. Fixed to.

  The lens barrel FPC 50 is a lens barrel driving power supply member for supplying power to the above-described imaging device substrate, a driving source for driving the lens barrel, and the like. The lens barrel FPC 50 is electrically connected to a driving source (zoom driving unit 11 and focus driving unit 12) and a second group FPC 48, and the end of the lens barrel FPC is electrically connected to the imaging apparatus substrate.

  Next, the operation of the lens barrel of the present embodiment having the above configuration will be described.

  When the drive ring 46 is rotated by the zoom drive unit 11, the rectilinear groove 46e in the inner peripheral portion of the drive ring 46 is engaged with the drive pin 45c of the moving cam ring 45, so that the moving cam ring 45 also rotates. The moving cam ring 45 moves in the optical axis direction while rotating along the cam groove 47 a of the fixed cylinder 47.

  Since the first group barrel 31 and the second group barrel 32 that are cam-fitted to the moving cam ring 45 are restricted in rotation by the straight barrel 49, when the moving cam ring 45 rotates, the inner circumference of the moving cam ring 45 The position in the optical axis direction changes along the cam grooves 45a and 45b. In this way, the first lens group 21 and the second lens group 22 can be arranged at specified positions. FIG. 2 described above shows a use state in which the lens barrel is in the extended state and the first group lens 21, the second group lens 22, and the third group lens 23 are arranged at predetermined positions where photographing is possible.

  Here, as described in the background art, in the conventional lens barrel shown in FIG. 7, incident light from the outside is reflected by the bent portion of the second group FPC to generate a ghost. Since there is a harmful effect, there is a problem that a slight deflection remains in the second group FPC.

  Therefore, in this embodiment, in order to take the deflection of the second group FPC 48 inside the lens barrel, a thin plate-like shape is formed between the base wall portion 44b of the base 44 of the lens barrel and the second group FPC 48 as shown in FIG. The sheet 51 is inserted.

  FIG. 3 is a central sectional view showing the configuration of the lens barrel and the state in which the second group FPC is bent.

  In FIG. 3, a sheet 51 is a thin plate-like elastic member made of a resin obtained by punching a resin sheet. The fixing portion of the sheet 51 is fixed along the base wall portion 44b of the base 44 (along the location where the second group FPC 48 is disposed), and the distal end side extends to an opening 44a provided in the base wall portion 44b. The leading end side of the sheet 51 (the extending portion 51b (see FIG. 4)) abuts on the bent portion generated at the bent portion of the second group FPC 48, and exerts a force in the direction of extending the bent portion of the second group FPC 48 by the elasticity of the sheet 51. .

  As a result, the second group FPC 48 is drawn outward of the lens barrel, and the bent portion of the second group FPC 48 inside the lens barrel does not bend in the direction approaching the optical axis as in the prior art (FIG. 7). It will be away from the optical axis. This makes it difficult for incident light from the outside of the lens barrel to strike the second group FPC 48. In addition, since the incident light beam hits the second group FPC 48 and is reflected, it does not pass through the third group lens 23 as in the prior art (FIG. 7), and therefore it is difficult for the light beam to enter the image sensor 24. Thereby, generation | occurrence | production of a ghost can be suppressed.

  Here, a drive ring 46 is disposed on the inside of the base wall 44b of the base 44, that is, on the optical axis side, and the drive ring 46 rotates during the zoom operation of the lens barrel. When the sheet 51 is bent in the direction of the optical axis by the reaction force of the second group FPC 48, if the leading end of the sheet 51 comes into contact with the rotating drive ring 46, it may cause damage or malfunction.

  Therefore, in the present embodiment, the sheet 51 is bent in the space formed by the opening 44a of the base wall portion 44b of the base 44, and the sheet 51 does not enter the optical axis side of the base wall portion 44b. is doing.

  Next, a detailed configuration of the second group barrel 32, the second group FPC 48, the barrel FPC 50, and the base 44 around the sheet 51 is shown in FIG.

  FIG. 4 is a perspective view showing the mounting structure of the second group FPC of the lens barrel.

  In FIG. 4, unnecessary portions are omitted for convenience of explanation. A focus driving unit 12 (focus motor) and a zoom driving unit 11 (zoom motor 65) are fixed to the base 44 of the lens barrel. In addition, a lens barrel FPC 50 for supplying power to electrical components including each motor is fixed to the base 44.

  The base 44 is provided with a protrusion 44c. The lens barrel FPC 50 is fixed to the base 44 by press-fitting the protrusion 44 c of the base 44 into a hole provided in the lens barrel FPC 50. A fixing material such as an adhesive may be used for fixing the lens barrel FPC 50. The lens barrel FPC 50 is provided with a plurality of wiring exposed portions 50 a (hereinafter referred to as lands) for electrical connection with the second group FPC 48.

  On the other hand, a second group FPC 48 extends from the second group barrel 32. At the end of the second group FPC 48, a connection portion 48a for connecting the second group FPC 48 to the lens barrel FPC 50 is provided. The connecting portion 48 a of the second group FPC 48 is provided with a hole 48 b corresponding to the protrusion 44 c of the base 44. The second group FPC 48 is fixed to the base 44 by press-fitting the protrusion 44 c of the base 44 into the hole 48 b of the connection portion 48 a of the second group FPC 48.

  A plurality of lands 48 c corresponding to the plurality of lands 50 a of the lens barrel FPC 50 are provided in the connection portion 48 a of the second group FPC 48. By connecting the plurality of lands 48c of the second group FPC 48 and the plurality of lands 50a of the lens barrel FPC 50 by soldering, the second group FPC 48 is electrically connected to the lens barrel FPC 50. As described above, the second group FPC 48 is fixed to the lens barrel by press-fitting to the base 44 and soldering to the lens barrel FPC 50.

  Here, the sheet 51 is sandwiched between the lens barrel FPC 50 and the second group FPC 48 and fixed to the base 44. The sheet 51 is provided with a hole 51 a corresponding to the protrusion 44 c of the base 44. The sheet 51 is fixed to the base 44 by press-fitting the protrusion 44 c of the base 44 into the hole 51 a of the sheet 51.

  The sheet 51 is provided with an extending portion 51 b and extends to the opening 44 a of the base 44. The extending portion 51b of the sheet 51 is brought into contact with the bent portion of the second group FPC 48, so that the second group FPC 48 is pulled out to the outside of the lens barrel.

  Thus, the sheet 51 is sandwiched and fixed between the second group FPC 48 and the base wall portion 44 b of the base 44 between the lens barrel FPC 50 and the second group FPC 48. The sheet 51 may be fixed by being sandwiched between the lens barrel FPC 50 and the base wall portion 44 b of the base 44. In that case, the sheet 51 is also securely fixed to the base 44 by firmly fixing the lens barrel FPC 50 to the base 44.

  By the way, in order to effectively take the deflection of the second group FPC 48 by the sheet 51, the sheet 51 needs to be securely fixed between the second group FPC 48 and the base wall portion 44 b of the base 44. The reason is that it is impossible to apply tension to the second group FPC 48 when the sheet 51 can move freely. In particular, it is important to eliminate the floating of the sheet 51.

  As described above, in the present embodiment, the sheet 51 is sandwiched between the second group FPC 48 and the base wall portion 44b of the base 44 (or between the lens barrel FPC 50 and the base wall portion 44b of the base 44). 51 is fixed so as not to float.

  Further, the second group FPC 48 and the lens barrel FPC 50 are prevented from floating by connecting the plurality of lands 48c of the second group FPC 48 and the plurality of lands 50a of the lens barrel FPC 50 with solder. As a result, the sheet 51 is further prevented from floating.

  Further, the sheet 51 is configured in a shape that does not overlap with the plurality of lands 48c of the second group FPC 48 and the plurality of lands 50a of the lens barrel FPC 50 when viewed from the planar projection direction. The reason is to prevent the sheet 51 from being deformed by heat at the time of solder connection.

  In addition, the second group FPC 48 is not damaged by arranging the sheet 51 to be made of resin in order to place the sheet 51 in a state of being in direct contact with the second group FPC 48.

  Further, since the sheet 51 can be easily manufactured by punching a resin sheet, the manufacturing cost is suppressed.

  Further, the sheet 51 is disposed adjacent to a solder connection portion between the plurality of lands 48 c of the second group FPC 48 and the plurality of lands 50 a of the lens barrel FPC 50. Since the sheet 51 is made of resin, it is possible to avoid the occurrence of inadvertent conduction between components (springs, leaf springs, and the like) for taking the FPC flexure and solder as in the prior art.

  FIG. 5 is a central sectional view showing a state of the second group FPC when the lens barrel is retracted.

  FIG. 5 shows a retracted state in which the lens barrel is shortened the most. In recent years, the zoom magnification of the lens barrel has been increased, while the thickness of the imaging device has been reduced, and the second group FPC, which has become longer as the amount of movement of the second group lens barrel, has increased. It has become difficult to store when retracted.

  In the present embodiment, as shown in FIG. 5, the sheet 51 can be accommodated in the lens barrel by pulling the second group FPC 48 outwardly when the lens barrel is retracted. .

  As described above, according to the present embodiment, the sheet 51 is sandwiched and fixed between the second group FPC 48 and the base wall portion 44b of the base 44, and comes into contact with the bent portion generated at the bent portion of the second group FPC 48. As a result, a force is applied in the direction of extending the bent portion. As a result, the second group FPC 48 can be bent in a small space and at a low cost. As a result, it is possible to suppress the incident light beam to the lens barrel from being reflected by the second group FPC 48 and reaching the image sensor 24, and thus it is possible to suppress the occurrence of ghost.

[Second Embodiment]
The second embodiment of the present invention is different from the first embodiment in the point described in FIG. Other elements of the present embodiment are the same as the corresponding ones of the first embodiment.

  FIG. 6 is a view showing a mounting structure of the second group FPC of the lens barrel according to the present embodiment.

  In FIG. 6, a lens barrel FPC 100 and a second group FPC 101 are wired to the lens barrel. A base opening 103 is formed in the base 102 of the lens barrel. Other parts are the same as those in the first embodiment, and the description thereof is omitted.

  The lens barrel FPC 100 is fixed to the base 102. The second group FPC 101 is fixed in a state of being superimposed on one surface (front side of the paper) of the lens barrel FPC 100. A part of the lens barrel FPC 100 extends to the base opening 103 to form an extending portion 100a. The extending portion 100 a of the lens barrel FPC 100 is in contact with the bent portion of the second group FPC 101. Thereby, there exists an effect which takes the bending of 2nd group FPC101 by the function similar to the sheet | seat 51 of the said 1st Embodiment.

  Note that the extending portion 100a of the lens barrel FPC 100 has no metal pattern and is composed of only a resin base material. Therefore, the extension part 100a of the lens barrel FPC 100 has elasticity similarly to the sheet 51 of the first embodiment.

  As described above, according to the present embodiment, by using a part of the lens barrel FPC 100 to bend the second group FPC 101, a separate member for removing the bending of the second group FPC 101 is unnecessary. Become. Accordingly, it is possible to take the deflection of the second group FPC 101 in a small space and at a low cost while achieving reduction of parts and simplification of assembly. As a result, it is possible to suppress the incident light rays to the lens barrel from being reflected by the second group FPC 101 and reaching the image sensor, and thus it is possible to suppress the occurrence of ghost.

32 2nd group lens barrel 44b Base wall 48, 101 2nd group FPC
50, 100 Lens tube FPC
51 Sheet 100a Extension part

Claims (7)

A lens barrel that includes a movable barrel that holds a lens and is movable in the optical axis direction, and a base having an opening,
A power supply member that extends from the movable lens barrel, is pulled out of the lens barrel through the opening of the base, is fixed to the base, and supplies power to the movable lens barrel;
An elastic member that is arranged along an arrangement position of the power supply member in the base, and has elasticity in a direction in which the power supply member in the opening of the base comes into contact with the power supply member and extends.
A lens barrel comprising:   The lens barrel according to claim 1, wherein the opening of the base is configured to allow deformation of the elastic member. A lens barrel drive power supply member electrically connected to the drive source for driving the lens barrel and the power supply member;
The connecting portion between the power supply member and the lens barrel drive power supply member is disposed adjacent to the position where the power supply member is disposed on the base,
The lens barrel according to claim 1, wherein the elastic member is sandwiched and fixed between the power feeding member and the base. A lens barrel drive power supply member electrically connected to the drive source for driving the lens barrel and the power supply member;
The connecting portion between the power supply member and the lens barrel drive power supply member is disposed adjacent to the position where the power supply member is disposed on the base,
The lens barrel according to claim 1, wherein the elastic member is sandwiched and fixed between the lens barrel drive power supply member and the base.   The lens barrel according to any one of claims 1 to 4, wherein the elastic member is configured as a plate-like member and is made of a resin.   5. The lens barrel according to claim 3, wherein the elastic member is configured as a part of the lens barrel drive power supply member and is formed of a resin.   The lens barrel according to claim 1, wherein the movable barrel has at least a shutter mechanism.

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