JP2006221104A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device capable of reducing reaction force by a flexible printed board connecting a movable part and a fixing part, and capable of reducing the space required in laying the flexible printed board. <P>SOLUTION: The optical device is provided with the movable member for holding a lens group, a fixing member for supporting the movable part to be movable in a plane perpendicular to the optical axis, and the flexible printed board for electrically connecting the movable member and the fixing member. The flexible printed board includes first parts (29b, 29e, and 29c) fixed to the fixing member, a second part (29e) extended in the direction of the optical axis from the first parts toward the movable part, and third parts (29aP and 29aY) branching at the second part, laid to the opposite directions each other around the optical axis, and fixed at approximately facing positions across the optical axis of the movable part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention is obtained by a video camera, a digital still camera, or other photographing apparatus, a lens barrel thereof, or an optical system that captures moving images or still images using an image pickup device such as a CCD disposed on the focal plane of the optical system. The present invention relates to an optical apparatus such as a binocular or an astronomical telescope for observing an image of a subject with the naked eye, or a lens barrel thereof. In particular, the present invention relates to an electrical connection structure in an image blur correction device that is incorporated in these optical devices and optically corrects the image blur.

  Conventionally, in order to correct image blur due to camera shake or the like that is likely to occur in hand-held shooting, a part of the main optical system of the imaging device or observation device is used as a correction lens, and this correction lens is shifted in a direction to absorb image blur. It is known that image blur is eliminated by causing the image blur. Such a shift type image blur correction apparatus has two systems of drive means and position detection means in directions substantially orthogonal to each other in order to accurately position the correction lens in a plane perpendicular to the optical axis of the main optical system. Position feedback control.

In general, the driving means is composed of an electromagnetic actuator comprising a combination of a coil and a permanent magnet, and the position detecting means is composed of a combination of a magnet and a magnetic detection element or a combination of a light emitting element and a light receiving element.
When electric parts such as coils and magnetic detection elements are arranged on the movable member to be shifted, a flexible printed circuit board is mainly used for wiring to the fixed member from the viewpoint of assembly and reliability, but the flexible printed circuit board is relatively strong. Since it has elasticity, smooth movement of the movable member may be hindered depending on how it is routed, and various proposals have been made to ensure image blur correction performance.

As a method of connecting such a flexible printed circuit board to a movable member, for example, in Patent Document 1, the flexible printed circuit board is moved as long as possible along the outer periphery of the movable member so that the flexible printed circuit board is moved to the maximum extent of the movable member. The influence on the moving member is minimized by avoiding bending as much as possible.
In Patent Document 2, the first flexible print cable and the second flexible print cable are fixed to the fixed frame so as to be substantially parallel to the sliding direction of the first lens moving frame, and the flexible print is performed. The influence of the reaction force generated by the bending of the cable is minimized to both the yawing frame and the pitching frame to prevent the deterioration of the control characteristics.
Moreover, in patent document 3, the reaction force by the deformation | transformation which arises by routing of a flexible substrate is prevented by bend | folding about 90 degree | times in the middle of routing a flexible substrate.
JP 2000-321611 A JP 2000-214508 A JP 2001-100074 A

By the way, in recent years, an imaging device in which a lens barrel is mounted is required to be further downsized and a design with less protrusion in order to improve portability and storage.
Naturally, there is a need for a smaller lens barrel and a so-called collapsible lens barrel that is stored when not in use.
However, if the lens barrel is further reduced in size, the space for routing the flexible printed circuit board that connects the movable member and the fixed member in the image blur correction device will be significantly reduced. In addition, since the space for arranging the coil and the permanent magnet as the driving means is relatively limited, the force that can be generated with respect to the limited electric energy is absolutely reduced.
In addition, the reaction force generated by the deformation of the flexible printed circuit board is inversely proportional to the cube of the length of the deformable portion, so that when the length is shortened, the reaction force rapidly increases.

  As described above, when the image shake correction apparatus is further reduced in size, as shown in Patent Document 1 or Patent Document 2, when the flexible printed circuit board is bent and drawn in a bow shape, the movable member is moved by the reaction force of the deformation. If the deformation of the flexible printed circuit board returns, it will be displaced. During normal shooting, the correction lens is electrically held around a position that substantially coincides with the optical axis of the main optical system, so that a large amount of electrical energy is consumed to constantly counter the reaction force caused by deformation of the flexible printed circuit board. Will continue. In addition, due to the reaction force of the one-way flexible printed circuit board, a driving means having a generation force larger than necessary is required, which is contrary to downsizing.

  Further, in Patent Document 3, the reaction force of the flexible printed circuit board is reduced by bending the flexible printed circuit board by approximately 90 degrees in the course of routing. If the angle deviates from the normal value, the reaction force will increase. Further, in the retractable lens barrel, each lens group constituting the main optical system is moved by the rotation of the members near the outside around the optical axis, so that the space allowed for the image blur correction device is the inside of the rotating member. However, it is difficult to reduce the reaction force by bending the flexible printed circuit board.

  According to the present invention, the reaction force due to the flexible printed circuit board connecting the movable part and the fixed part can be made as small as possible, and the space necessary for routing the flexible printed circuit board can be made as small as possible. It is an object of the present invention to provide an optical device that enables the above.

The present invention provides an optical device configured as follows.
That is, the optical device of the present invention includes a movable member that holds a lens group, a fixed member that supports the movable part so as to be movable in a plane orthogonal to the optical axis, and electrically connects the movable member and the fixed member. A flexible printed circuit board to be connected,
The flexible printed circuit board includes a first part fixed to the fixing member, a second part extending in the optical axis direction from the first part to the movable part side, and the second part is branched around the optical axis. And a third portion that is routed in opposite directions and is fixed at a substantially opposite position across the optical axis of the movable portion.

  According to the present invention, the reaction force due to the flexible printed circuit board connecting the movable part and the fixed part can be made as small as possible, and the space necessary for routing the flexible printed circuit board can be made as small as possible. It is possible to realize an optical device that can do this.

The present invention can achieve the object of the present invention by the above-described configuration, but in the embodiment of the present invention, by applying the present invention, it can be specifically configured as follows. For example, in an optical device having an image blur correction device, a movable part (see, for example, 19 in FIGS. 2 and 3) that holds an image blur correction lens group and the movable part are supported so as to be movable in a plane orthogonal to the optical axis. And a flexible printed circuit board (for example, see 29 in FIGS. 2 and 3), and the movable part and the fixed part are electrically connected by the flexible printed circuit board. In the optical apparatus having the image blur correction device to be connected, the flexible printed circuit board includes a part (see, for example, 29b, 29e, and 29c in FIG. 4) of which one end is fixed to the fixing part and a part of the flexible printed circuit board that is fixed to the fixing part. A portion extending in the optical axis direction toward the movable portion (see, for example, 29e in FIG. 4) and the extending end side of the extending portion are branched and before being routed in opposite directions around the optical axis. (29AP e.g. FIG 4, 29AY reference) portion fixed to a position substantially opposed across the optical axis of the movable portion can be configured to include a, a. As a result, the movable part drawn around the correction lens barrel of the flexible printed circuit board has its both ends fixed to the movable part and forms an arc shape by itself, so the reaction force of the flexible printed circuit board at this part cancels out inside the movable part. Thus, it is possible to prevent unnecessary force from being applied to the fixed portion and the movable portion.
In an embodiment of the present invention, the flexible printed circuit board has a length of a portion that is branched and routed in opposite directions around the optical axis and fixed at a substantially opposite position across the optical axis of the movable part. However, the structure set to the length which does not exert the reaction force by the said routing part with respect to the said movable part can be taken.
Further, the movable portion that holds the lens group may be applied to a shift lens barrel that holds an image blur correction lens, and the flexible printed circuit board may be configured to be routed just outside the shift lens barrel. it can. Thereby, the space required for routing the flexible printed circuit board can be further reduced.

Examples of the present invention will be described below.
In the embodiments of the present invention, the above-described present invention is applied to have a variable magnification optical system having a four-group configuration, and in a non-use state, the distance between the lens groups is reduced compared with that during normal use, thereby greatly increasing the total lens length. A so-called collapsible lens barrel was constructed.
FIG. 1 is an exploded perspective view of a retractable lens barrel in the present embodiment.
FIG. 2 shows a sectional view of the retractable lens barrel of the present embodiment when retracted.
FIG. 3 shows a sectional view in one state when the retractable lens barrel of this embodiment is used.

1 to 3, L1 is a first lens group, L2 is a second lens group, L31 is a third movable lens group that moves in a plane perpendicular to the optical axis and performs a shake correction operation, and L32 is relative to L31. The third fixed lens group L4 fixed in the direction perpendicular to the optical axis is a fourth lens group that performs a focusing operation by moving in the optical axis direction.
Reference numeral 1 denotes a first group barrel that holds the first lens unit L1, and reference numeral 1a denotes three pipes that are arranged at equal intervals in the circumferential direction at the rear end portion of the first group barrel 1 and fixed in the radial direction by press fitting or the like. These linear rollers 1b are three cam pins having a base portion rotatably fitted to the three linear rollers 1a and having a conical cam follower at the tip.
Reference numeral 2 denotes a second group barrel that holds the second lens unit L2, and 2a denotes three pipes that are arranged at equal intervals in the circumferential direction at the rear end portion of the second group barrel 2 and fixed in the radial direction by press-fitting or the like. The rectilinear rollers 2b are three cam pins having a base portion rotatably fitted to the three rectilinear rollers 2a and having a conical cam follower at the tip.

3 is a shift unit that allows the third movable lens unit L31 to move in a plane perpendicular to the optical axis with respect to the third fixed lens unit L32. 3a is a pipe that is fixed to the rear end of the shift unit 3 by press-fitting or the like. A cylindrical roller 3b is a cam pin having a base portion rotatably fitted to the roller 3a and having a conical cam follower at the tip.
Reference numeral 4 denotes a moving frame for holding the fourth lens unit L4, and 5, 6 and 7 are guide bars for supporting the shift unit 3 and the moving frame 4 so as to be movable in the optical axis direction.

The shift unit 3 is supported by guide bars 5 and 6, and the moving frame 4 is supported by guide bars 7 and 6.
Reference numeral 8 denotes a support frame for positioning and fixing the front end portions of the guide bars 5, 6, and 7. Reference numeral 9 denotes a rear end portion for positioning and fixing the rear end portions of the guide bars 5, 6, and 7, and a rear portion for mounting an image pickup device such as a CCD. It is a lens barrel. The support frame 8 is fixed to the rear barrel 9 with three screws. Reference numeral 10 denotes a fixed cylinder, which has three guide grooves 10a for linearly guiding the linear rollers 1a and 2a in the optical axis direction. The fixed cylinder 10 is fixed to the rear barrel 9 with three screws.
A cam ring 11 is rotatably held on the outer periphery of the fixed cylinder 10. The inner wall of the cam ring 11 has a plurality of cam grooves (not shown) corresponding to the conical cam followers at the tip ends of the cam pins 1b, 2b, 3b. The third lens unit L1, L2, L31, L32 is advanced and retracted in the optical axis direction to perform a zooming operation. A stopper 32 restricts the rotation of the cam ring 11 and is fixed to the rear barrel 9 with screws. Reference numeral 33 denotes a diaphragm device that controls the aperture diameter of the optical system, and is a so-called iris diaphragm device that varies the aperture area by rocking a plurality of diaphragm blades in conjunction with each other.

Reference numeral 12 denotes a focus motor as drive means for moving the fourth lens unit L4 in the optical axis direction to perform focusing operation. A lead screw 12a coaxial with the rotating rotor is attached to the moving frame 4. The fourth lens unit L4 is engaged with the rack 4a and moved by rotation of the rotor. Further, the play of the moving frame 4, the guide bars 6, 7, the rack 4a, and the lead screw 12a is offset by the torsion coil spring 4b. The focus motor 12 is fixed to the support frame 8 with a single screw.
A zoom motor 13 is a driving means for rotating the cam ring 11. The zoom motor 13 is engaged with a gear portion 11a provided at the rear end portion of the cam ring 11 to rotate the cam ring 11, thereby changing the magnification. To do. The zoom motor 13 is fixed to the rear barrel 9 with two screws.

Reference numeral 14 denotes a photo interrupter for electrically detecting the switching between light shielding and light transmission due to the movement of the light shielding portion 4c formed in the moving frame 4 in the optical axis direction and detecting the reference position of the fourth lens unit L4. Focus reset switch.
Reference numeral 15 denotes a photo interrupter, which is a zoom reset switch for electrically detecting the switching between light shielding and light transmission caused by the movement of the lever 16 and detecting the reference position for zooming. One end of the lever 16 is pressed against a radial cam (not shown) provided at the rear end portion of the cam ring 11 by a torsion coil spring 17, and the lever 16 swings in accordance with the cam lift of the cam ring to thereby provide a reference for the rotational direction of the cam ring. Detect position.

Next, the configuration of the shift unit 3 that allows the third movable lens unit L31 to move within a plane perpendicular to the optical axis will be described with reference to FIGS. FIG. 4 shows an exploded perspective view of the shift unit 3.
The third movable lens unit L31 has a vertical direction for correcting image blur in the PITCH direction (camera longitudinal angle change) and a horizontal direction for correcting image blur in the YAW direction (camera horizontal angle change). While being regulated by the guide mechanism in a plane perpendicular to the optical axis, it is independently driven and controlled by dedicated drive means and position detection means in the vertical and horizontal directions, and positioned at any position around the optical axis. Is done.
Since the longitudinal and lateral driving means and the position detecting means have the same configuration at an angle of 90 degrees, only the longitudinal direction (expressed in the cross-sectional view of FIG. 2) will be described here. In addition, the numbers indicating the components in the drawing are represented by subscripting P for vertical components and Y for horizontal components.

Reference numeral 18 denotes a shift base serving as a base for the fixed portion of the shift unit, which holds the third fixed lens unit L32 and is held movably in the optical axis direction by the guide bars 6 and 7, and is camped via the cam pin 3b. The rotation of the ring 11 serves as a base for moving the entire shift unit 3 forward and backward in the optical axis direction.
Reference numeral 19 denotes a shift lens barrel that is a movable member that holds the third movable lens group L31 that is a lens group that shifts.
Reference numerals 20a, b, c denote three balls sandwiched between the shift base 18 and the shift barrel 19, and the material thereof is, for example, SUS304 (austenitic stainless steel so as not to be attracted by a driving magnet, which will be described later. Steel) is preferred. The surfaces on which the balls 20a, b, and c are in contact are 18a, b, and c on the shift base 18 side, and 19a, b, and c on the shift lens barrel 19 side, respectively. When the three balls have the same nominal diameter with respect to the optical axis of the system, the third movable lens unit L31 is made to light by suppressing the difference in the positions of the three surfaces in the optical axis direction. Holding and moving guidance can be performed while maintaining a right angle to the axis.
Reference numeral 21 denotes a sensor base as a rear-side fixing member, which is coupled to the shift base 18 with two screws.

Next, driving means will be described.
22P is a drive magnet magnetized in two radial directions with respect to the optical axis, 23P is a back yoke for closing the magnetic flux on the rear side of the drive magnet 22P in the optical axis direction, and 24P is attached to the shift lens barrel 19. The coil 25P fixed by the above is a yoke for closing the magnetic flux on the front side in the optical axis direction of the driving magnet 22P, and has a projection shape substantially the same as that of the driving magnet 22P in the optical axis direction.
Reference numeral 26P denotes a member for positioning the yoke 25P. The position of the yoke 25P is determined by the positioning member 26P and is fixed to the back surface of the coil 24P. The driving magnet 22P, the back yoke 23P, and the yoke 25P constitute a magnetic circuit.

When a current is passed through the coil, a Lorentz force is generated in the direction substantially perpendicular to the magnetization boundary of the two-pole magnetization of the driving magnet 22P. Move. Since the said structure is arrange | positioned in the vertical and horizontal direction, a movable member can be driven to two directions substantially orthogonal.
Further, the drive magnet 22P and the back yoke 23P are fixed to the shift base 18 which is a fixed member, and the yoke 25P is fixed to the shift barrel 19 which is a movable member together with the coil 24P. The yoke 25P is attracted to the driving magnet 22P by force. By arranging the magnetic circuit and the three balls so that the resultant force in the magnetic circuit in the vertical and horizontal directions works inside the three balls, the shift barrel 19 holds the three balls 20a, b, and c. To urge the shift base 18.
Further, a lubricating oil having a viscosity that prevents the balls from easily falling off the contact surfaces even when the balls 20 are not sandwiched between the shift base 18 and the shift lens barrel 19 between the three contact surfaces. Thus, even if the inertial force exceeding the urging force is applied to the shift barrel 19 and the ball is in a non-clamping state, it is possible to prevent the ball from easily deviating.

Next, the state during driving of the shift barrel will be described with reference to FIGS. 5 (a) and 5 (b) are views showing only the drive means, and FIG. 5 (a) shows that the optical axis of the third movable lens group L31 is substantially coincident with the optical axes of the other lens groups. It is a figure of time.
A protrusion 25Pa is formed on the yoke 25P by half punching, and the position is located at the boundary of the two-pole magnetization of the driving magnet 22P. At this time, the protrusion 25Pa is at an approximately equal distance from both poles of the two-pole magnetization of the driving magnet 22P, so that the force with which the both pull the protrusion is almost equal and balanced.
Further, as described above, the yoke 25P has substantially the same projected shape as that of the driving magnet 22P in the optical axis direction. Therefore, the magnetic flux entering and exiting from the two magnetic poles of the driving magnet 22P is the yoke. The state shown in FIG. 5A is the most magnetically stable state.

FIG. 5B shows a state where the coil 24P and the yoke 25P, that is, the shift lens barrel 19 are moved upward by energizing the coil. It will be displaced from the stable state of (a) according to the generated force in the coil. The state of FIG. 5B is displaced from the stable state in terms of the magnetic circuit, and is pulled back to the state of FIG. 5A. However, the protrusion 25Pa of the yoke 25P is displaced, so that It is close and far from the N pole. Since the magnitude of the magnetic force is inversely proportional to the square of the distance, it can be seen that the force from the magnetic pole acting on the protrusion 25Pa works in the direction of promoting the displacement. As described above, the effect of the protrusion 25 Pa cancels the closing force of the magnetic circuit, and can be displaced with a smaller applied voltage.
As can be understood from the above explanation, the center position of the magnetic force can be controlled by changing the size of the yoke and the size of the bulge. For example, the weight of the shift group is controlled by the magnetic force. Therefore, the yoke 25P may be intentionally shifted downward, or the protrusion 25Pa may be shifted upward.

Next, the relationship between the shift base 18 and the shift lens barrel 19 with respect to the ball 20 will be described with reference to FIGS. Here, the three balls have the same relationship.
In FIG. 6A, the shift barrel 19 is at the center position (the third movable lens unit L31 coincides with the optical axis of the other lens unit), and the ball 20 also restricts the movement of the ball of the shift base 19. It is in a state where it is located at the center within the restricted range. FIG. 6B shows a state in which the shift barrel 19 is driven by the driving means in this upward direction in the direction of the arrow.
The shift barrel 19 is driven to the end of the movable machine provided at another location and moved by a from the center position. Since the ball 20 is held between the shift base 18 and the shift barrel 19, it rolls in the direction of the arrow in FIG. 6A and moves to the position in FIG. 6B. The rolling friction is sufficiently smaller than the sliding friction, and the shift lens barrel 19 moves relative to the shift base 18 by the rolling of the ball without sliding between the ball and the contact surface. At this time, since the shift barrel 19 and the shift base 18 are moved in the opposite directions relative to the center of the ball, the movement amount of the ball with respect to the shift base 18 is half of the movement amount of the shift barrel 19. Thus, the amount of movement b is half of a (a ÷ 2).

The restricted range of movement of the ball 20 provided on the shift base 18 is represented by (R + b + c) from the center, where R is the ball radius. Here, c is a mechanical margin.
FIG. 6A shows a case where the ball 20 is also at the center of the limit range when the shift lens barrel 19 is at the center position. However, if the ball 20 is at a position shifted by c or more from the center of the limit range. In this case, when the shift lens barrel 19 is driven as shown in FIG. 6B, the ball 20 hits the limit range of the shift base 18 before the shift lens barrel 19 moves by a and hits the machine end. Then, the shift barrel 19 slides with the ball 20 and is driven to the machine end while pressing the ball 20 against the limit end. When the shift lens barrel 19 is further returned to the center position from this state, the ball 20 rolls back to the position at a distance c from the center of the control range.

  In this way, when the shift lens barrel 19 is driven to the machine ends on both sides in the vertical and horizontal directions and returned to the center position, the center position of the ball 20 is initially c from the center of the limit range regardless of the position. Will be positioned within the square of the distance. This series of operations is called a ball reset operation. Normally, the optical performance of the lens is designed so that the best performance is obtained when the optical axes of the lens groups that are configured coincide with each other. Therefore, the third movable lens group L31 is eccentric with respect to the other lens groups. As a result, the performance becomes disadvantageous. Of course, the optical performance has no practical problem within the actually required shift range. If the shift barrel 19 is driven in the two orthogonal directions by the same amount at the same time, the shift barrel 19 moves to a position of √2 times in the diagonal direction. In consideration of the position of the other, image stabilization is performed within the range of a circle centered on the optical axis or a polygon close to a circle, and the three balls are similar in shape. It will be a rolling exercise within a half range.

The movement limit range of the ball is a quadrilateral having four sides that are substantially parallel to two substantially orthogonal directions in which the driving means generates a force. This is in line with the above-described range of movement of the ball in the actual use state. In addition, if the ball has a round or polygonal shape, there may be a case where the position cannot be correctly reset to a position where the ball does not hit the limit end in the actual use state due to the ball reset operation. The movement limit range of the ball is a quadrilateral having four sides substantially parallel to two directions that are substantially perpendicular to each other where the driving means generates a force. Surfaces 18a, b, c that contact the balls of the shift base 18 and the shift lens barrel 19 with the gap larger than half of the maximum mechanical movable amount in the same direction of the movable member or the maximum moving amount in actual use. A configuration in which the shift lens barrel 18 can be supported and guided only by rolling the ball without actually hitting the limit end in actual use if the ball is reset while minimizing the areas 19a, b, and c. It is said.
In addition, as described above, by applying lubricating oil between the ball and each contact surface, the sliding frictional force between the ball and the contact surface can be reduced to reduce the influence on the position control. I can do it.

Next, returning to FIGS. 2 to 4, the position detecting means will be described.
Reference numeral 27P denotes a detection magnet that is magnetized in two radial directions with respect to the optical axis, and the magnetic flux on the rear side in the optical axis direction is closed by the yoke 25P. Both are fixed to the shift barrel 19.
Reference numeral 28 </ b> P denotes a hall element that converts the magnetic flux density into an electric signal, and is positioned and fixed to the sensor base 21. The position detection means is constituted by the above configuration.

Here, the state of the magnetic flux in the optical axis direction front side of the detection magnet 27P will be described with reference to FIG.
In FIG. 7, the horizontal axis represents the position in the radial direction with respect to the optical axis, and the vertical axis represents the magnetic flux density.
The center of the horizontal axis is a boundary portion of the two-pole magnetization of the detection magnet 27P, and at this time, the magnetic flux density becomes zero.
This also corresponds to a position where the optical axis of the third movable lens unit L31 substantially coincides with the other lens units. Within the range indicated by the two-dot chain line, the magnetic flux density changes linearly to such an extent that it does not cause a practical problem. By detecting this change in magnetic flux density as an electrical signal from the Hall element by appropriate signal processing, the position of the third movable lens unit L31 can be detected.

FIG. 8 shows an example of a signal processing circuit for a Hall element.
Reference numeral 28 denotes a Hall element, and the operational amplifier of 40 is combined with resistors 40a, 40b, and 40c to supply a constant current to the Hall element 28. An output with respect to the magnetic flux density of the Hall element 28 is output by an operational amplifier 41 and resistors 41a, 41b, 41c, and 41d. Differentially amplified. The resistor 41e is a variable resistor, and an electric output signal with respect to the magnetic flux density can be shifted by changing the resistance value. The optical axis of the third movable lens group L31 is relative to the optical axes of other lens groups. The output is adjusted to be equal to the reference potential Vc at the matching position. The operational amplifier 42 is combined with the resistors 42a and 42b to invert and amplify the output of the operational amplifier 41 with respect to the reference potential Vc, and by changing the resistance value of the variable resistor 42b, the ratio of the change in the output voltage to the change in the magnetic flux density is predetermined. Can be adjusted to the value.

Returning to FIGS. 2 to 4 again, the description will be continued.
Reference numeral 29 denotes a flexible printed circuit board (hereinafter referred to as shift flex) for electrically connecting the coil 24 and the hall element 28 to an external circuit. The coil 24 fixed to the shift lens barrel 19 The movable portion 29a to be connected, the portion 29e extending in the optical axis direction to pull the movable portion 29a into the fixed portion, and the portions 29b, 29e and 29b to which the hole element 24 fixed to the sensor base 21 is connected are connected. A portion 29c fixed to the rear surface of the shift base 18 and a U-turn portion 29d that expands and contracts as the shift unit 3 advances and retreats.
Reference numeral 30 denotes a flexible presser metal plate which fixes the shift flexible 29 to the shift base 18 and guides the U-turn portion 29d of the shift flexible 29.
Reference numeral 31P denotes a hole element pressing metal plate, which fixes the shift flexible 29b portion to the sensor base 21.

The method of fixing the shift flexible 29 to the shift barrel 19 will be further described with reference to FIGS. 9 (a) and 9 (b).
FIG. 9B is a diagram for explaining a fixed part on the PITCH side.
The movable portion 29a of the shift flex 29 has an arm portion 19a whose tip 29aP receives the coil 24P of the shift barrel 19, a hook portion 19b provided on the shift barrel 19, and a flex presser provided on the positioning member 26P. Are positioned on the shift barrel 19 by being respectively sandwiched between the projections 26Pa.
The tip 29aY of the movable portion 29a of the shift flexible 29 in the YAW direction is also fixed to the shift barrel 19 in the same manner. In FIG. 9A, the movable portion 29a of the shift flex 29 is shifted by deforming the shift barrel 19 as shown by a broken line when the shift barrel 19 is displaced leftward with respect to the shift base 18. The movement of the lens barrel 9 is absorbed.

Next, the shape of the shift flex 29a will be further described with reference to FIG.
FIG. 10A schematically shows the shift flex 29 of FIG. 9A. The same number is given to the same part. The movable portion 29a of the shift flex 29 is set to have such a length as to form an arc in contact with the direction in which the fixed portions 29aP and 29aY are fixed to the shift barrel 19 from the fixed portions. In other words, when the end portions 29aP and 29aY are fixed to the shift lens barrel 19 without attaching the bending flexure or the like in advance, the shift flex 29a has a shape naturally formed by the elasticity of the shift flex 29a itself. By fixing to the shift base 18 at the extended position of the drawing-in portion 29e in the optical axis direction in this shape, it is possible to prevent the reaction force of the shift flexible movable portion 29a from being received at the position of the shift barrel 19. .
If the relative position of the shift barrel 19 and the shift base 18 at this time is set to a position where the optical axes of the third movable lens unit L31 and the third fixed lens unit L32 coincide, the reaction force of the shift flex at the control center position. For example, when the use posture is limited to the vicinity of the horizontal in a photographing apparatus dedicated to moving images, a position not subject to the reaction force of the above shift flex is intentionally set to the shift base 18. By shifting the shift barrel 19 upward, the mass of the movable part may be supported by the deflection of the shift flexible so as to suppress the consumption of electric energy at the control center position.

FIG. 10A shows an example in which the shift flexible tip portions 29aP and 29aY are pulled out in the same direction, while FIG. 10B shows an example in which the shift flexible tip portions 29aP and 29aY are pulled out slightly outward.
Similarly to FIG. 10A, the shift flexible movable portion 29a is set to such a length as to form an arc in contact with the drawing direction from the fixed portions 29aP and 29aY, thereby moving the movable portions in the PITCH and YAW directions. The reaction force of flexible can be offset. In addition, the shift flexible movable portion 29a can be arranged in a smaller space while securing the movable portion length of the shift flexible by drawing the outside of the third movable lens group L31 in a shape substantially along the lens group. It has become.

Next, with reference to FIGS. 11A and 11B, the configuration and arrangement of the position detection means, the function of suppressing the rotation of the movable member by the two vertical and horizontal magnetic circuits, and the movement at that time will be described. FIG. 11A is a view of the movable part as viewed from the front side of the optical axis.
The two magnetic circuits, which are urging members, urge the movable part in the optical axis direction. At the same time, as described above, the yokes 25P and 25Y are substantially the same in the optical axis direction as the drive magnets 22P and 22Y. Therefore, the rotation direction of the shift barrel 19 with respect to the optical axis depends on the positions of the two vertical and horizontal driving magnets fixed to the shift base 18 with respect to the shift base 18 (sensor base 21). Rotation is suppressed.
27P and 27Y are position detection magnets as described above, and the boundary of the two-pole magnetization is arranged in a direction perpendicular to the detection direction (vertical and horizontal directions in the figure), and with respect to the movement of other axes. It is obvious that if the magnet is large to some extent with respect to the amount of movement, the magnetic flux distribution can be practically prevented from changing with respect to the Hall element that forms part of the position detection means, so that the position can be detected independently on two axes. It is.
In addition, since the intersection of the detection directions of the two-axis position detection means coincides with the optical axis, the output value changes in a relatively small angle range with respect to the rotation around the optical axis. Absent. When a driving force is applied to the shift barrel 19 by the driving means, the movement of the shift barrel 19 depends on the positional relationship between the position where the force of the driving means is generated and the center of gravity of the movable part, or the connection position of the connected flexible printed circuit board. Depending on the shape, the two magnetic circuits only suppress the rotation, so the movable part may rotate around the optical axis as it is driven.

  A change in the detection output value of the position detection means at that time will be described with reference to FIG. Now, assume that the position detection point in the vertical direction is A, the position detection point in the horizontal direction is B, the optical axis of the lens group is C, and the movement of each point is observed when the shift barrel 19 rotates around the D point. . Within a range where the rotation angle is not so large, points A, B and C move in a direction perpendicular to the line connecting points D. The motion vectors at each point are Va, Vb, and Vc, respectively, and are decomposed in the direction of the two axis position detection axes, and the components are Vax, Vay, Vbx, Vby, Vcx, and Vcy, respectively. As described above, since the position detection means does not have sensitivity in the direction perpendicular to the detection axis, the vectors of Vax and Vby are not detected by the position detection means. By the way, since the intersection of the two detection axes coincides with the optical axis, the relationship of Vcx = Vbx and Vcy = Vay is established with respect to the motion vectors Vcx and Vcy of the optical axis C. This indicates that the position detection means can correctly detect the change in the optical axis position of the third movable lens unit L31 accompanying the rotation about a point away from the optical axis, that is, the shift amount without being influenced by the rotation. Thus, the shift barrel can be moved to the correct position by positioning control including drive means and detection means described later.

FIG. 12 is a system diagram of driving of the lens barrel of the photographing apparatus equipped with the lens barrel having the blur correction function in this embodiment and blur correction.
3, 50 is an optical low-pass filter for removing the high frequency component of the spatial frequency of the subject, and 51 is an image sensor for converting an optical image arranged on the focal plane into an electrical signal. An electrical signal a read from a certain CCD or CCD 51 is converted into an image signal by the camera signal processing circuit 52.
A microcomputer 53 controls lens driving. When the power is turned on, the microcomputer 53 monitors the outputs of the focus reset circuit 54 and the zoom reset circuit 55 and rotates the respective stepping motors with the focus motor drive circuit 56 and the zoom motor drive circuit 57 so that each lens group is moved to the optical axis. Move in the direction. The outputs of the focus reset circuit 54 and the zoom reset circuit 55 come to the positions where the respective movable members are set in advance (the light shielding member provided on the movable member shields the light emitting portion of the photo interrupter provided on the fixed portion, or The microcomputer can know the absolute position of each lens group by counting the number of subsequent driving steps of the stepping motor in the microcomputer with the position as a reference. Thereby, accurate focal length information is obtained. This series of operations is referred to as zoom and focus reset operation.

Reference numeral 58 denotes an aperture drive circuit for driving the aperture device 33, and the aperture diameter of the aperture is controlled based on the brightness information b of the video signal taken into the microcomputer 53.
Reference numerals 59 and 60 denote PITCH (vertical tilt angle) and YAW (horizontal tilt angle) angle detection circuits of the optical device. The angle is detected by, for example, outputting an output of an angular velocity sensor such as a vibration gyroscope fixed to the photographing apparatus. It is done by integrating. The outputs of both circuits 59 and 60, that is, the information on the tilt angle of the photographing apparatus is taken into the microcomputer 53.
Reference numerals 61 and 62 denote PITCH (longitudinal) and YAW (lateral) coil drive circuits for moving the third movable lens unit L31 perpendicularly to the optical axis in order to perform blur correction, and include magnets including magnets. A coil is disposed in the gap of the circuit, and a driving force for shifting the third movable lens unit L31 is generated by a so-called moving coil configuration. Reference numerals 63 and 64 denote PITCH (vertical direction) and YAW (horizontal direction) position detection circuits for detecting the shift amount with respect to the optical axis of the third movable lens unit L 31, and are taken into the microcomputer 53. When the third movable lens unit L31 moves perpendicular to the optical axis, the passing light beam is bent, and the position of the subject image formed on the CCD 51 moves. By controlling the amount of movement of the image at this time by the microcomputer 53 so that the moving amount is the same as the moving direction of the image when the photographing device is actually tilted, Even so, a so-called blur correction in which the image being formed does not move can be realized.

  In the microcomputer 53, the tilt signal of the photographing apparatus obtained by the PITCH angle detection circuit 59 and the YAW angle detection circuit 60 and the shift amount of the third movable lens group L31 obtained from the PITCH position detection circuit 63 and the YAW position detection circuit 64 are obtained. The shift lens barrel 19 is driven by the PITCH coil drive circuit 61 and the YAW coil drive circuit 62, respectively, by subtracting the signals and amplifying the respective difference signals and performing appropriate phase compensation. By this control, the third movable lens unit L31 is positioned and controlled so as to make the above difference signal smaller and kept at the target position. Furthermore, in this embodiment, the zooming operation is performed by the relative movement of the first to third lens units, so the amount of image movement with respect to the shift amount of the third movable lens unit L31 changes depending on the focal length. The shift amount of the third movable lens unit L31 is not determined as it is based on the tilt signal of the photographing apparatus obtained by the PITCH angle detection circuit 59 and the YAW angle detection circuit 60, but is corrected based on the focal length information and the image of the image due to the inclination of the photographing apparatus is corrected. The movement is canceled by shifting the third movable lens unit L31.

Although the above description is an operation at the time of blur correction, the above-described ball reset operation is performed subsequent to the zoom and focus reset operation at the time of power-on or by performing time-sharing simultaneously when the photographing apparatus is not used. Even if the ball is deviated from the correct position due to the impact of the ball, it is possible to demonstrate excellent shake correction performance by the ball rolling guide immediately after the reset operation.
In addition, the microcomputer resets the ball and determines when the camera is not in use (when observing video on a monitor, recording video on a recording device, etc.) using a microcomputer (for example, shooting) By observing the value of the tilt angle of the apparatus and determining whether it is carried around), it may be possible to always guarantee excellent shake correction during use. However, since the correction angle range for blur correction is generally about 0.5 to 1 degree, in actual shooting, it is possible to operate each function of the shooting device or search for a subject to be shot on the viewfinder. Since the movement more than the correction angle is given to the photographing apparatus, the ball may be reset by the movement.
When the ball shifts from rolling friction to sliding friction, the blur compensation performance deteriorates for a moment due to the discontinuous increase in frictional force, but if movement beyond the correction angle range is given to the device, after that, only the ball rolling will guide Therefore, it is possible to perform good blur correction.
Although the above is description of an Example, it cannot be overemphasized that this invention is not limited to the structure of an Example, and what kind of thing may be sufficient if it is the structure shown by the claim.

The disassembled perspective view of the retractable lens barrel in the Example of this invention. Sectional drawing which shows the structure at the time of retraction of the retractable lens barrel of the Example of this invention. Sectional drawing which shows the structure in one state at the time of use of the retractable lens barrel of the Example of this invention. The disassembled perspective view of the shift unit in the Example of this invention. The figure explaining the drive of the shift unit in the Example of this invention. The figure explaining the guide mechanism in the Example of this invention. The figure explaining the magnet for a detection in the Example of this invention. An example of the signal processing circuit of the Hall element in the Example of this invention. The figure explaining the connection part of the flexible printed circuit board in the Example of this invention. The figure explaining the shape of the flexible printed circuit board in the Example of this invention. The figure explaining the rotation suppression function in the Example of this invention. 1 is a diagram illustrating a system as an image blur correction lens in an embodiment of the present invention. FIG.

Explanation of symbols

1: 1 group lens barrel 2: 2 group lens barrel 3: shift unit 4: moving frames 5, 6, 7: guide bar 8: support frame 9: rear lens barrel 10: fixed cylinder 11: cam ring 12: focus lens -13: Zoom motor 14, 15: Photo interrupter 16: Lever
17: Torsion coil spring 18: Shift base 19: Shift lens barrel 20: Ball 21: Sensor base 22: Driving magnet 23: Back yoke 24: Coil 25: Yoke 26: Positioning member 27: Detection magnet 28: Hall element 29: Flexible printed circuit board (shift flexible)
30: Flexible holding sheet metal 31: Hole element holding sheet metal 32: Stopper 33: Aperture device

Claims (4)

A movable member that holds the lens group, a fixed member that supports the movable part in a plane perpendicular to the optical axis, and a flexible printed board that electrically connects the movable member and the fixed member,
The flexible printed circuit board includes a first part fixed to the fixing member, a second part extending in the optical axis direction from the first part to the movable part side, and the second part is branched around the optical axis. And an optical device comprising: a third portion that is routed in opposite directions and is fixed at a substantially opposite position across the optical axis of the movable portion.   The third portion of the flexible printed circuit board is set such that a length from the branch portion to the fixed portion does not exert a reaction force by the routing portion on the movable member. The optical device according to claim 1.   The optical apparatus according to claim 1, further comprising a shift barrel in which an image blur correction lens is held by the movable member.   The optical apparatus according to claim 3, wherein the flexible printed circuit board is routed outside the shift barrel.

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