Lens barrel, camera and lens barrel adjustment device

A lens barrel comprises a fixed optical system though which a subject image enters into the lens barrel along with an optical axis, a retreatable blur correction optical system that corrects an image blur by moving within a plane ranging perpendicular to the optical axis in an operating position and that retreats to a storage position from the operating position, a blur correction optical system drive unit that drives the retreatable blur correction optical system within the plane ranging perpendicular to the optical axis, and a correction information recording unit at which reference position correction information is recorded, the correction information indicating a reference position for the retreatable blur correction optical system within the plane ranging perpendicular to the optical axis.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lens barrel equipped with a retreatable optical system that retreats from a position on the optical axis for storage, a camera that includes the lens barrel and an adjustment device that adjusts the lens barrel.

2. Description of Related Art

Japanese Laid Open Patent Publication No. 2003-315861 discloses a retractable lens barrel used in photographing operation executed in a camera. The length of this lens barrel in storage is reduced by allowing some of a plurality of lens groups to move (slide) rotationally around a rotating shaft fixed to the lens barrel so as to retreat along a direction extending perpendicular to the optical axis and storing the other lens groups into the space thus created.

The lens barrels used in photographing operations executed in cameras in the related art include those equipped with optical blur correction devices. A blur correction device detects a vibration to which the optical system has been subjected via an angular speed sensor or the like and reduces the extent of an image blur manifesting on the image forming plane by driving some (blur correction lens group) of a plurality of lens groups within a plane ranging perpendicular to the optical axis based upon the extent of vibration thus detected.

Japanese Laid Open Patent Publication No. 2004-233922 discloses an example of a lens barrel in the related art, which includes a lens group made to retreat away from the optical axis. Decentering may occur in this lens barrel due to inconsistent accuracy in mechanical portions and the like used in the retreating operation, and for this reason, it includes an aligning mechanism that displaces the lens group by shifting it along a direction perpendicular to the optical axis so as to reduce the extent of the decentering.

However, the addition of the aligning mechanism leads to an increase in the number of required parts, resulting in a lens barrel with a more complex structure. The addition of an aligning mechanism becomes particularly problematic in the case of a lens barrel equipped with a blur correction device, since the sufficient installation space for the aligning mechanism needs to be secured in the already tight available space.

According to the first aspect of the invention, a lens barrel comprises: a fixed optical system through which a subject image enters into the lens barrel along with an optical axis; a retreatable blur correction optical system that corrects an image blur by moving within a plane ranging perpendicular to the optical axis in an operating position and that retreats to a storage position from the operating position; a blur correction optical system drive unit that drives the retreatable blur correction optical system within the plane ranging perpendicular to the optical axis; and a correction information recording unit at which reference position correction information is recorded. The correction information indicates a reference position for the retreatable blur correction optical system within the plane ranging perpendicular to the optical axis.

According to the second aspect of the invention, a lens barrel comprises: a fixed optical system though which a subject image enters into the lens barrel along with an optical axis; a blur correction optical system supported so as to be allowed to move within a plane ranging perpendicular to the optical axis to correct an image blur; a retreatable optical system that moves between an operating position and a stored position away from the optical axis, the retreatable optical system being constituted with either an optical system independent of the blur correction optical system or an optical system constituting part of the blur correction optical system; a blur correction optical system drive unit that drives the blur correction optical system within the plane ranging perpendicular to the optical axis; and a correction information recording unit at which reference position correction information is recorded. The correction information indicates a reference position for the blur correction optical system within the plane ranging perpendicular to the optical axis.

The reference position may be a position where the optical axis of the retreatable blur correction optical system or the blur correction optical system substantially coincides with the optical axis of the fixed optical system.

It is preferred that the correction information recording unit provides the correction information to an information acquisition device disposed at a camera body on which the lens barrel is mounted.

A camera according to another aspect of the invention comprises: a fixed optical system through which a subject image enters into a lens barrel along with an optical axis; a retreatable blur correction optical system that corrects an image blur by moving within a plane ranging perpendicular to the optical axis in an operating position and that retreats to a storage position from the operating position; a blur correction optical system drive unit that drives the retreatable blur correction optical system within the plane ranging perpendicular to the optical axis; and a correction information recording unit at which reference position correction information is recorded. The correction information indicates a reference position for the retreatable blur correction optical system within the plane ranging perpendicular to the optical axis.

A camera according to another aspect of the invention comprises: a fixed optical system though which a subject image enters into a lens barrel along with an optical axis; a blur correction optical system supported so as to be allowed to move within a plane ranging perpendicular to the optical axis to correct an image blur; a retreatable optical system that moves between an operating position and a stored position away from the optical axis, the retreatable optical system being constituted with either an optical system independent of the blur correction optical system or an optical system constituting part of the blur correction optical system; a blur correction optical system drive unit that drives the blur correction optical system within the plane ranging perpendicular to the optical axis; and a correction information recording unit at which reference position correction information is recorded. The correction information indicates a reference position for the blur correction optical system within the plane ranging perpendicular to the optical axis.

The camera may further comprises: an imaging device that captures a subject image entering thereto via the lens barrel and outputs an image signal, and the correction information recorded at the correction information recording unit may be generated based upon an output from the imaging device.

According to another aspect of the invention, it is preferred that the retreatable blur correction optical system or the retreatable optical system is configured to swing from the operating position to the storage position around the optical axis as the lens barrel retracts into a camera body.

A lens barrel adjustment device according to the present invention, uses to adjust the lens barrel noted above. The lens barrel adjustment device comprises: an imaging device that captures a subject image formed via the lens barrel and outputs an image signal; a correction information generation unit that evaluates an image signal output from the imaging device while displacing the retreatable blur correction optical system or the blur correction optical system by controlling the blur correction optical system drive unit at the lens barrel and generates reference position correction information indicating a reference position for the retreatable blur correction optical system or the blur correction optical system to be assumed within the plane perpendicular to the optical axis; and a recording unit that records the correction information output by the correction information generation unit into a recording medium disposed within the lens barrel.

DESCRIPTION OF EMBODIMENTS

First Embodiment

The following is an explanation of the camera achieved in the first embodiment of the present invention.

As shown inFIG. 1A, the camera in the first embodiment may be a digital still camera. The digital still camera in the figure includes a camera body300and a lens barrel100, which is inserted and fixed at an opening300aformed at the camera body300and is equipped with an optical blur correction device. It is to be noted that reference numeral300bindicates a shutter release button.

FIG. 1Bis a sectional view of the lens barrel in the first embodiment in a wide-angle photographing state (operating state).FIG. 2is a sectional view of the lens barrel in the telephoto photographing state andFIG. 3is a sectional view taken along III-III inFIG. 1in the direction of the arrows.

The lens barrel100includes photographic lens group which may be zoom lens groups constituted with, for instance, four lens groups. These photographic lens groups include a first lens group L1, a second lens group L2, a blur correction lens group (third lens group) L3and a fourth lens group L4, disposed in this order starting from the subject side (hereafter referred to as an objective side) along an optical axis I in the photographing state. The first lens group L1and the second lens group L2are each a zooming lens group that moves along the optical axis Ito adjust the focal length of the photographic lens groups and are respectively fixed in a first lens group chamber10and a second lens group chamber20, each of which includes an annular lens frame. It is to be noted that the blur correction lens group L3and the fourth lens group L4also function as zooming lenses and move along the optical axis I.

The blur correction lens group L3displaces itself by shifting within a plane ranging substantially perpendicular to the optical axis I in correspondence to a vibration to which the lens barrel100has been subjected, so as to reduce the extent of image blur occurring at the image forming plane. The blur correction lens group L3is fixed in a blur correction lens group chamber30, which includes an annular lens frame, and the blur correction lens group chamber30, in turn, is supported at a vibration frame210of a blur correction unit200to be detailed later. It is to be noted that unlike the blur correction lens group L3, the lens groups L1, L2and L4are fixed optical systems which do not undergo such displacement, maintaining fixed positions relative to the optical axis I.

The fourth lens group L4is a focusing lens group that adjusts the photographing distance (focusing position) of the photographic lens groups as it moves along the optical axis I, and is fixed in a fourth lens group chamber40, which includes an annular lens frame. The fourth lens group chamber40is driven along the optical axis I under AF control of the known art executed by using a focusing mechanism (not shown).

A shutter unit50, a CCD60and a low pass filter (LPF)70are mounted in the lens barrel100. The shutter unit50, disposed on the light-entry side of the blur correction lens group L3, adjusts the exposure quantity indicating the extent of exposure at the CCD60. The shutter unit50includes a shutter portion constituted with a plurality of thin plastic pieces. The CCD60is a solid imaging element that converts an image formed via the photographic lens groups to electrical signals and outputs the electrical signals, and is disposed on the light exit side of the fourth lens group L4. The LPF70is an optical filter provided so as to prevent moiré from manifesting in the captured image and is disposed between the fourth lens group L4and the CCD60.

The lens barrel100further includes a first lens group barrel110, a second lens group holding frame120, a blur correction lens group holding frame130, a fixed barrel150, a first cam barrel160, a second cam barrel170, a linear guide key180and a CCD stage190.

The first lens barrel chamber10is fixed inside of the first lens group barrel110formed in a substantially cylindrical shape. The first lens group barrel110is inserted inside of the second cam barrel170. The first lens group barrel110is allowed to move along the optical axis I via a cam mechanism formed between itself and the second cam barrel170when the lens barrel100shifts from the photographing state to the stored state or when the focal length is being adjusted. As shown inFIGS. 1A, and1B and2, the first lens group barrel110assumes a position at the front end of the lens barrel100toward the objective side in the photographing state.

The first lens group barrel110is equipped with a guide member111and a lens barrier unit112. The guide member111guides the vibration frame210of the blur correction unit200to be described in detail later. The guide member111is disposed over an area located on the outside of the first lens group L1at the end surface of the first lens group barrel110toward the objective side, so as to project out toward the image side along the optical axis I. The guide member111assumes a tapered shape so as to become gradually thinner toward its front end side (toward the image). The guide operation executed via this guide member111is to be explained later.

The lens barrier unit112, disposed on the objective side of the first lens group L1, protects the surface of the first lens group L1on the entry side while the lens barrel100is in the stored state. The lens barrier unit112, comprising a barrier113, a barrier drive ring114, a barrier receptacle115and a barrier cover116, is fixed at the end of the first lens group barrel110on the objective side.

The second lens group holding frame120, which is a frame structure mounted on the outside of the second lens group chamber20, is inserted on the inside of the first lens group barrel110. The second lens group holding frame120is allowed to move along the optical axis I independently of the first lens group barrel110via a cam mechanism formed between itself and the first cam barrel160when the lens barrel100shifts from the photographing state to the stored state or vice versa, or when the focal length is being adjusted. The second lens group chamber20includes a flange portion formed as a projecting collar at its outer circumferential surface and is fastened onto the second lens group holding frame120via a nut21at the flange portion. An adjustment washer22used to fine-adjust the position of the second lens group L2is disposed at the surface of the flange portion on the side opposite from the nut21.

The blur correction lens group holding frame130is a frame structure that holds the blur correction unit200which includes the blur correction lens group L3and the blur correction lens group chamber30. The blur correction lens group holding frame130is inserted on the inside of the first lens group barrel110. The blur correction lens group holding frame130is allowed to move along the optical axis I via a cam mechanism formed between itself and the first cam barrel160as the lens barrel100shifts from the photographing state to the stored state or vice versa.

The fixed barrel150, formed in a substantially cylindrical shape constitutes the base portion of the lens barrel100and is fixed onto the camera body (not shown) and is disposed on the outermost side at the lens barrel100. The first cam barrel160and the second cam barrel170, each formed in a cylindrical shape, are allowed to rotate around the optical axis I relative to the fixed barrel150via an interlocking mechanism (not shown).

The first cam barrel160is inserted on the inside of the fixed barrel150. A cam follower formed at the outer circumferential surface of the first cam barrel160is inserted in a cam groove formed at the inner circumferential surface of the fixed barrel150. Cam followers formed at the second lens holding frame120and the blur correction lens group holding frame130are inserted in cam grooves formed at the inner circumferential surface of the first cam barrel160. The second cam barrel170is inserted further on the inside of the first cam barrel160, and the first lens group barrel110is inserted on the inside of the second cam barrel170. A cam follower formed on the outer circumferential surface of the first lens group barrel110is inserted in a cam groove formed at the inner circumferential surface of the second cam barrel170.

The linear guide key180linearly guides the first lens group barrel110, the second lens group holding frame120and the blur correction lens group holding frame130along the optical axis I relative to the fixed barrel150, regardless of whether or not the first cam barrel160and the second cam barrel170are rotating. The CCD stage190, fixed at the end of the fixed barrel150toward the image along the optical axis I, closes off the opening end of the fixed barrel150. The CCD60and the LPF70are fixed onto the CCD stage190.

The blur correction unit200includes the vibration frame210, a voice coil motor (VCM)220, a position detector230, a blur correction unit cover240and a flexible printed circuit board (FPC)250.

As shown inFIG. 3, the vibration frame disposed at the surface of the blur correction lens group holding frame130toward the image, is supported so as to move parallel to the blur correction lens group holding frame130within a plane ranging perpendicular to the optical axis I. The vibration frame210is a drive target member that is driven within the plane perpendicular to the optical axis I under blur correction control of the known art. The vibration frame210includes a recessed portion210aformed by recessing its outer circumferential edge. The guide member111mentioned earlier is inserted in the recessed portion210a.

A rotating shaft211, a spring212and a rotation stopper213are mounted at the vibration frame210. The rotating shaft211, formed as a pin projecting out from the surface of the vibration frame210toward the image along the optical axis I, axially supports the front end of an arm portion31formed to radially extend from the outer circumferential surface of the blur correction lens group chamber30the outside thereof, so as to allow the arm portion31to rotate or swing as necessary. The central axis of the rotating shaft211is set so as to extend substantially parallel to the optical axis I. In addition, the rotating shaft211is disposed further upward relative to the optical axis I along a diagonal direction within a plane of the vibration frame210ranging perpendicular to the optical axis in a normal photographing state. It is to be noted that the term “normal photographing state” used in the description refers to a state in which photographing operation is executed by setting the optical axis I and the longitudinal side of the image plane substantially horizontal.

The spring212is, held between the rotating shaft211and the arm portion31, and applies a rotational force to the blur correction lens group chamber30in a specific direction (in the counterclockwise direction viewed from the image side along the optical axis I in the embodiment) around the rotating shaft211, relative to the vibration frame210. The rotation stopper213is constituted with a projected portion projecting out from the surface of the vibration frame210and regulates the rotation of the blur correction lens group chamber30caused by the force applied from the spring212, as it comes in contact with a projected portion32at the blur correction lens group chamber30. The projected portion32is formed on the outer peripheral surface of the blur correction lens group chamber30at a position achieving substantial symmetry with the position of the arm portion31relative to the optical axis.

At the area where the arm portion31connects with the rotating shaft211, a cam face portion34is formed to range around the circumference of the rotating shaft211. The cam face portion34is formed so as to range spirally relative to the rotating shaft211. In other words, the height of the cam face portion34measured along the length of the rotating shaft211continuously changes in correspondence to the angle measured around the circumference of the rotating shaft. As the lens barrel100shifts from the photographing state to the stored state, the blur correction lens group chamber30causes a pin33fixed at the CCD stage190to press down on the cam face portion34. As the pin33slides along the sloped surface of the cam face portion34, the arm portion31having the cam face portion34rotates around the rotating shaft211against the force applied from the spring212. As a result, the blur correction lens group chamber30rotates along the clockwise direction around the rotating shaft211.

The VCM220is an actuator that drives the vibration frame210along the direction extending perpendicular to the optical axis I in response to a control signal provided by a blur correction control unit (not shown). The VCM220includes a coil221, a magnet222and yokes223and224, as shown inFIGS. 1 and 2. The coil221is fixed to the vibration frame210. The magnet222is a permanent magnet fixed onto the blur correction lens group holding frame130at a position facing opposite the coil221. The yoke223is fixed to the surface of the magnet222on the side opposite from the coil221. The yoke224is fixed to the blur correction unit cover240so as to face opposite the surface of the coil221on the side opposite from the magnet222. The blur correction unit cover240is disposed at the vibration frame210further toward the image side and fixed to the blur correction lens group holding frame130.

The blur correction unit200in the first embodiment corrects blurring attributable to pitching and yawing occurring at the lens barrel100and includes VCMs220each used to drive the vibration frame210to correct the blur caused by pitching or yawing. In the following explanation, the VCM that drives the vibration frame210to correct the pitching blur is referred to by attaching the suffix P and the VCM220that drives the vibration frame210to correct the yawing blur is referred to by attaching the suffix Y (suffixes are likewise attached to position detectors230to be described later).

As shown inFIG. 3, the VCM220P is disposed further downward along the optical axis I in the regular photographing state. The VCM220Y is set at a side of the optical axis I in the normal photographing state, at a position distanced from the VCM220P by 90° around the optical axis I.

The position detectors230each include a Hall element fixed to the vibration frame210and a magnet fixed to the blur correction lens group holding frame130. The Hall element detects the intensity of the magnetic field, which changes as the vibration frame210becomes displaced relative to the blur correction lens group holding frame130. The position detectors230each detect the position of the vibration frame210relative to the blur correction lens group holding frame130based upon the change in the detected magnetic field intensity. The position detector230P is disposed over an area above the VCM220Y in the normal photographing state. The position detector230Y is disposed over an area on the opposite side of the optical axis I relative to the VCM220Y.

Through the FPC250which is disposed so as to bridge the space between the fixed barrel150and the vibration frame210, power is supplied to the coils221at the VCMs220and output signals from the Hall elements at the position detectors230are transmitted.

The operation executed as the lens barrel100in the first embodiment shifts from the photographing state to the stored state is explained.

FIG. 4is a lateral section of the lens barrel100shifting from the photographing state to the stored state. The lens barrel100first rotationally drives the first cam barrel160and the second cam barrel170to move the first lens group barrel110in the second lens group holding frame130toward the image along the optical axis I. As the first lens group barrel110moves, the relative distance between the guide member111fixed to the first lens group barrel110and the vibration frame210, measured along the optical axis I, become smaller. Then, as the interval between the first lens group L1and the third lens group L3becomes smaller than the minimum value assumed in the photographing state, the guide member111is inserted at the recessed portion210aformed at the vibration frame210of the blur correction unit200.

As explained earlier, the guide member111assumes a tapered shape, gradually becoming thicker from its front end (the image side along the optical axis I) toward its base side (toward the first lens group barrel110), and has a sloped surface inclined relative to the optical axis I. The guide member111adopting this structure can be inserted at the vibration frame210over a significant depth and as the guide member111slides against the inner surface of the recessed portion210a, it becomes displaced within the plane ranging perpendicular to the optical axis I. Ultimately, the vibration frame210becomes held in the state in which the optical axis of the blur correction lens group L3is substantially aligned (centered) with the optical axis of the other lens groups (seeFIG. 4).

After the blur correction lens group L3becomes held in the centered state as described above, the first cam barrel160is rotationally driven continuously, and thus, the blur correction lens group holding frame130starts to move toward the image along the optical axis I. As the blur correction lens group holding frame moves toward the image, the pin33fixed to the CCD stage190presses against the cam face portion34at the blur correction lens group chamber30.

FIG. 5is a lateral section of the lens barrel100in the stored state.FIG. 6is a sectional view of the lens barrel100in the stored state, taken across a plane that contains the optical axis.

The blur correction lens group L3retreats from the optical axis I of the other lens groups as the pressure is applied to the cam face portion34at the blur correction lens group chamber30, as shown inFIG. 5. When the retreating movement of the blur correction lens group L3ends, the lens barrel100moves the first lens group barrel110, the second lens group holding frame120and the blur correction lens group holding frame130further toward the image along the optical axis I. As a result, the fourth lens group L4and the blur correction lens group L3, having retreated from the optical axis I, become positionally aligned alongside the fourth lens group L4and the optical axis I, as shown inFIG. 6.

FIG. 7shows the structure of a camera1equipped with the lens barrel100described above.

The camera1includes a control circuit310and a memory320in addition to the lens barrel100. The control circuit310includes an MPU that individually controls the CCD60, the VCM220and the position detectors230, and executes exposure control, image processing, AF control, blur correction control and the like of the known art by controlling the entire camera1in a comprehensive manner. Reference position correction information used when driving the blur correction lens group L3within the plane perpendicular to the optical axis I is held in the memory320. When executing blur correction control, the control circuit310sets the center position for the blur correction lens group L3based upon the correction information. The method adopted when generating the correction information is to be described in detail later. The control circuit310and the memory320are housed inside a camera body (not shown) at which the lens barrel100is mounted.

The method adopted when adjusting the lens barrel100in the camera1(correction information generation method) is explained.

First, a test chart, i.e., the subject, is placed on the objective side of the lens barrel100and a subject image of the test chart formed via the lens barrel100is captured with the CCD60.

FIG. 8presents examples of the test chart. The test chart may be, for instance, a rectangular sheet410formed in correspondence to the image angle of the image captured with the CCD60with a dot marking411set at the center thereof, as shown inFIG. 8A. Alternatively, the test chart may be a sheet420similar to the sheet410with dot markings421set at the center and the periphery thereof, as shown inFIG. 8B.

If the various lens groups in the lens barrel100are not decentered from the optical axis I to a significant extent, the image of the marking411or421at the center of the test chart, retaining a clean, desirable shape without becoming deformed, is set at the center of the image field. The extent of deformation or blurring occurring in the images of the markings421at the periphery of the test chart are small enough to be disregarded.

If, on the other hand, a lens group is decentered relative to the optical axis I, the image of the marking411or421at the center of the test chart becomes misaligned from the center of the image or the image becomes deformed. At the same time, the images of the markings421at the periphery become deformed or blurred to a significant extent.

The control circuit310outputs a control signal to the VCMs220to displace the blur correction lens group L3by shifting it within the plane perpendicular to the optical axis, evaluates image signals output from the CCD60in sequence and detects the position of the blur correction lens group L3at which the image signals are evaluated at the highest level when the image of the marking411or421is at the center of the test chart or the image is not deformed. Then, the control circuit310records into the memory320information indicating the position of the blur correction lens group L3at which the image signals are evaluated at the highest level as correction information related to the reference position of the blur correction lens group L3, and then completes the adjustment of the lens barrel100. Namely, as the blur correction lens group L3is set at the reference position, the optical axis of the blur correction lens group L3substantially coincides with that of the other lens groups, then the subject image enters the CCD60with its optical axis perpendicular to the CCD60.

The correction information includes information indicating the direction of and the distance to the position described above, relative to the center position of the blur correction lens group L3set in the initial state (pre-adjustment state). For instance, the correction information may include information indicating the coordinates of the position along the X direction (pitching direction) and the Y direction (yawing direction). Then, during an operation of the camera1, the control unit310executes blur correction control by using the position ascertained based upon the correction information as the central position (reference position).

The following advantages are achieved in the first embodiment described above.(1) Based upon the position of the blur correction lens group L3when the best performance is yielded from the lens barrel100, the control circuit310generates the reference position correction information for the blur correction lens group L3. This correction information, indicating the center position of the blur correction lens group L3(the position assumed by the centered blur correction lens group), is used in the blur correction control. In other words, since the blur correction unit200can be utilized as an aligning mechanism unit that centers the blur correction lens group L3, the lens barrel100can be adjusted through a simple structure without having to provide a special aligning mechanism unit.(2) Based upon image signals output from the CCD60while photographing the test chart, the control circuit310detects the position of the blur correction lens group L3at which the best image quality is achieved and records the position thus detected as correction information into the memory320. Then, the center position (reference position) can be set for the blur correction lens group L3based upon the correction information, which allows the lens barrel100to be adjusted through a simple structure.

Second Embodiment

The lens barrel adjustment device achieved in the second embodiment of the present invention and the lens barrel adjustment method adopted in the lens barrel adjustment device are explained. The lens barrel adjusted in the second embodiment is similar to that explained in reference to the first embodiment.

This adjustment may be executed after assembling the lens barrel100before mounting the assembled lens barrel at the camera body300during, for instance, the camera manufacturing process, is performed by mounting the lens barrel100with the CCD60detached therefrom at an adjustment device500explained below.

FIG. 9shows the lens barrel100after the CCD60has been removed, mounted at the adjustment device500. The adjustment device500includes a CCD510, a control circuit520and a laser radiation device530. The CCD510is a solid-state imaging element mounted in place of the CCD60at the lens barrel100at the position at which the CCD60is normally mounted. The control circuit520includes an MPU that individually controls the CCD510as well as the VCMs220and the position detectors230at the lens barrel100. The control circuit520evaluates image signals output from the CCD510and generates correction information while driving the blur correction lens group L3to shift the blur correction lens group by controlling the VCMs220. The method adopted when generating the correction information is to be explained in detail later. The laser radiation device530is a recording unit that cuts the wiring formed on a flexible printed circuit board (FPC)600based upon the correction information generated by the control circuit520and records the correction information constituted of the cutting pattern on the FPC600.

The following is an explanation of the method adopted when adjusting the lens barrel100by utilizing the adjustment device500described above.

First, the lens barrel100whiteout the CCD60is mounted at the adjustment device500, as shown inFIG. 9. A test chart, i.e., the subject, is placed on the objective side of the lens barrel100and a subject image of the test chart formed via the lens barrel100is captured with the CCD510.

The control circuit520displaces the blur correction lens group L3by shifting it, evaluates image signals output from the CCD510in sequence, detects the position of the blur correction lens group L3at which the image signals are evaluated at the highest level, and thus generates correction information, as does the control circuit310in the first embodiment. The control circuit520then outputs the correction information thus generated to the laser radiation device530.

FIG. 10shows the FPC600, i.e., the recording medium in which the correction information is recorded by the laser radiation device530, withFIG. 10(a) showing the FPC in the pre-recording state andFIG. 10(b) showing the FPC in the post-recording state. The FPC600includes a base portion610and a wiring portion620. The base portion610is formed as a sheet constituted of a flexible material with an insulating property. The wiring portion620is a thin film constituted of a material achieving electrical conductivity, such as a metal, formed through etching or the like at the surface of the base portion610. The wiring portion620may include, for instance, nine contact points C0˜C8set at an end edge of the base portion610and a land portion621that achieves mutual continuity among the contact points C0˜C8. Based upon electrical continuity/non-continuity between the contact points C1˜C4and the contact point C0and between the contact points C5˜C8and the contact point C0, correction information corresponding to the X direction and correction information corresponding to the Y direction are recorded as four-bit information at each of the contact points C1˜C4and the contact points C5and C8.

The laser radiation device530cuts an area of the land portion621corresponding to a specific contact point with a laser so as to set each contact point either in a continuous state or a non-continuous state. For instance, the contact points C1, C3, C5and C6are set in the non-continuous state and the other contact points C2, C4, C7and C8are set in the continuous state in the example presented inFIG. 10(b).

The FPC600having undergone this processing is attached to a specific area of the outer surface of the lens barrel100. A read device (not shown) which includes contact points (not shown) to achieve electrical continuity with the individual contact points C0˜C8as the lens barrel100is mounted, is provided at the camera body300. Thus, by detecting the continuous/non-continuous states of individual contact points, the correction information inherent to the specific lens barrel100can be automatically transmitted to the control circuit310during the assembly process on, for instance, the production line at which the camera1is manufactured. The control circuit310, in turn, executes the blur correction control based upon the correction information transmitted thereto.

In addition to advantages similar to those of the first embodiment described above, the second embodiment achieves the following advantage.

The adjustment device500records the correction information generated while adjusting the lens barrel100onto the FPC600in a format that allows the correction information to be read by the read device on the camera body side. Since the correction information can be automatically transmitted to the camera body side as the lens barrel100is mounted at the camera body during the camera assembly process, the camera assembly process is simplified.

Variations

The present invention is not limited to the embodiments described above and allows for a number of variations and modifications.(1) While an explanation is given above on an example in which the blur correction optical system constitutes the retreatable optical system, the present invention is not limited to this example and may be adopted in a structure that includes a blur correction optical system and a retreatable optical system disposed independently of each other or in a structure in which part of the retreatable optical system is constituted with the blur correction optical system. For instance, in a structure that includes four lens groups, the second lens group may function as a blur correction lens group and the third lens group may be the retreatable lens group. In conjunction with this structure, the deterioration in the image quality attributable to misalignment of the retreatable optical system can be prevented by setting the reference position for the blur correction optical system so as to optimize the performance of the overall optical system.(2) While the FPC600, the land portion621of which can be cut via the laser radiation device530, is used as the recording unit in the second embodiment a recording means other than this may be utilized, instead. For instance, a two-dimensional barcode700such as that shown inFIG. 11may be used. Such a two-dimensional barcode700may be utilized in conjunction with a lens barrel adjustment device equipped with a printer for printing a two-dimensional barcode containing correction information instead of the laser radiation device530in the second embodiment and the printed barcode may be attached onto the lens barrel100. As the lens barrel100is mounted at the camera, the correction information recorded as the two-dimensional barcode should be read by a barcode reader and the correction information thus read should be input to the memory within the camera via an input/output device of the known art capable of reading data from and writing data into memory.

Furthermore, if the lens barrel100is assigned with unit identification information such as a serial number, data correlating this unit identification information with the correction information may be recorded while adjusting the lens barrel100and the data may subsequently be retrieved and input as the lens barrel100is mounted at the camera.(3) Instead of recording the correction information into the memory outside (on the camera body300) of the lens barrel100, the lens barrel100may include an internal memory where the correction information can be recorded.(4) While the lens barrel100is a photographic lens barrel mounted in a digital still camera that does not allow the use of exchangeable lenses, the present invention is not limited to this example and it may be adopted in lens barrels mounted at cameras that allow the use of exchangeable lenses, for example cameras using a light sensitive film or a silver halide film and movie cameras as well. The lens barrel100used in such applications does not include the CCD60, unlike the lens barrel100in the first embodiment. In the case of a digital camera or a movie camera that uses exchangeable lenses, the CCD60will be installed within the camera body.

The above described embodiments are examples, and various modifications can be made without departing from the spirit and scope of the invention.