JP2018124586A - Optical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an influence of urging force of a flexible substrate with respect to a correction lens.SOLUTION: An optical instrument comprises: a correction lens that corrects image tremors; a correction lens holding frame of the correction lens; a stationary support part that movably supports the correction holding frame; a driving element that is fixed to the correction lens holding frame, and drives the correction lens; a detection element that is fixed to the correction lens holding frame, and is used for position detection of the correction lens holding frame; a first fixed part that is fixed to the stationary support part; a first flexible substrate that supplies electric power to the driving element while elastically deforming between a second fixed part fixed to the correction lens holding frame and the first fixed part; a third fixed part that is fixed to the stationary support part; and a second flexible substrate that elastically deforms between a fourth fixed part fixed to the correction lens holding frame and the third fixed part, and supplies the electric power to the detection element while cancelling out at least a part of urging force generated due to the elastic deformation of the first flexible substrate.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an optical apparatus.

There is a camera shake correction device that is driven by attaching a coil to a correction lens (see, for example, Patent Document 1).
Japanese Patent Application Laid-Open No. 2008-224723

  When a coil is attached to a lens that is displaced, the elasticity of the flexible substrate that supplies driving power to the coil may affect the movement of the lens.

  According to the first aspect of the present invention, the correction lens that corrects the image blur in the optical system, the correction lens holding frame that holds the correction lens, and the correction lens holding frame on the moving plane that intersects the optical axis of the optical system. A fixed support portion that is movably supported, a driving element that is fixed to the correction lens holding frame and generates a driving force for driving the correction lens by being supplied with power, and fixed to the correction lens holding frame to While elastically deforming between the detection element supplied and used for detecting the position of the correction lens holding frame, the first fixing portion fixed to the fixing support portion, and the second fixing portion fixed to the correction lens holding frame Elastically deforming between the first flexible board for supplying power to the driving element, the third fixing part fixed to the fixing support part, and the fourth fixing part fixed to the correction lens holding frame , Elastic deformation of the first flexible substrate While canceling at least a portion of the biasing force generated by the optical device and a second flexible substrate for supplying power to the detection device is provided.

  The summary of the invention does not enumerate all the features of the present invention. Sub-combinations of these feature groups can also be an invention.

1 is a schematic diagram of an imaging apparatus 100. FIG. 4 is a perspective view of a correction lens unit 220. FIG. 4 is a perspective view showing the inside of a correction lens unit 220. FIG. 4 is a front view showing the inside of a correction lens unit 220. FIG. 3 is a cross-sectional view of a correction lens unit 220. FIG. 3 is a cross-sectional view of a correction lens unit 220. FIG. 4 is a front view of a correction lens unit 220. FIG.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. Not all combinations of features described in the embodiments are essential for the solution of the invention.

  FIG. 1 is a schematic diagram of the imaging apparatus 100. The imaging device 100 is an example of an optical device having a function of correcting image blur. The imaging device 100 includes a lens barrel 110 and a camera body 120. The lens barrel 110 has an optical system 112 including a plurality of lenses arranged on the optical axis X. The camera body 120 has an image sensor 122.

  The imaging device 100 captures an object image formed by the optical system 112 of the lens barrel 110 on the light receiving surface of the image sensor 122 by recording it as an electrical signal. In the following description, the object side with respect to the lens barrel 110 is described as the front side of the imaging apparatus 100. Further, the camera body 120 side with respect to the lens barrel 110 is referred to as a rear side.

  The lens barrel 110 further includes an image blur correction unit 200 that corrects image blur in the optical system 112. The image blur correction unit 200 includes a detection unit 210 and a correction lens unit 220.

  The detection unit 210 includes acceleration sensors 212 and 214 that detect acceleration in two directions that intersect the optical axis X and intersect each other. The detection unit 210 calculates the displacement of the lens barrel 110 based on the acceleration detected by the acceleration sensors 212 and 214.

  The correction lens unit 220 includes a correction lens 230 and an actuator 240. The correction lens 230 forms a part of the optical system 112 and is displaced in a direction intersecting the optical axis X, thereby displacing the image forming position of the image formed by the optical system 112 in the direction intersecting the optical axis X.

  The actuator 240 drives the correction lens 230 to move along the moving plane intersecting the optical axis X in order to cancel the image blur caused by the displacement of the lens barrel 110 calculated by the detection unit 210. As a result, image blur in the optical system 112 is compensated, and a clear image is formed on the image sensor 122.

  FIG. 2 is a perspective view of the correction lens unit 220. The correction lens unit 220 includes a correction lens 230 and a lens holding frame 232, a case 250 and a cover 260 that accommodate them, and flexible substrates 270 and 280.

  In the correction lens unit 220, the correction lens 230 is held by the lens holding frame 232. The assembly of the correction lens 230 and the lens holding frame 232 is accommodated and supported in a disk-shaped container formed by combining the case 250 and the cover 260.

  The case 250 is located on the back side in the drawing and has a plurality of fixing pins 252 at the peripheral edge. Thereby, the case 250 can be fixed to the lens barrel 110 to form a fixed support portion. The cover 260 is screwed to the case 250 with a plurality of fixing screws 262. Thus, the case 250 and the cover 260 are integrated, and when the case 250 is fixed to the lens barrel 110, the cover 260 is also fixed to the lens barrel 110.

  The cover 260 includes a central opening 264 provided in the center and a pair of passage holes 263 and 265 arranged on the side of the central opening. The central opening 264 has an inner diameter slightly larger than the diameter of the correction lens 230 accommodated in the case 250 and the cover 260 and exposes the correction lens 230 from the cover 260 to the outside. Each of the passage holes 263 and 265 allows the flexible substrates 270 and 280 to communicate with each other inside and outside the case 250 and the cover 260.

  The flexible boards 270 and 280 electrically couple the inside and the outside of the case 250 and the cover 260. When attention is paid to the first flexible substrate 280, a first fixing portion fixed to the outer surface of the case 250 is formed in the case-side fixing portion 282 located at one end of the flexible substrate 280 within the range shown in the figure. To do. The holding frame side fixing portion 284 located at the other end of the flexible substrate 280 is attached and fixed to the lens holding frame 232 accommodated inside the case 250 and the cover 260 to fix the second fixing portion. Form.

  Furthermore, the flexible substrate 280 has a spiral portion 286 that is bent in a clockwise spiral shape between the case side fixing portion 282 and the holding frame side fixing portion 284. By providing the spiral portion 286 to provide elasticity, a load applied to the flexible substrate 280 when the lens holding frame 232 is displaced with respect to the case 250 is reduced.

  Similarly, in the range where the second flexible substrate 270 appears in the drawing, the case-side fixing portion 272 of the flexible substrate 270 forms a third fixing portion fixed to the outer surface of the case 250. Further, the holding frame side fixing portion 274 of the flexible substrate 270 is attached and fixed to the lens holding frame 232 accommodated in the case 250 and the cover 260 to form a fourth fixing portion.

  Furthermore, the flexible substrate 270 has a spiral portion 276 that is bent in a counterclockwise spiral shape between the case side fixing portion 272 and the holding frame side fixing portion 274. By providing the spiral portion 276 to provide elasticity, a load applied to the flexible substrate 270 when the lens holding frame 232 is displaced with respect to the case 250 is reduced.

  Note that a pair of yokes 242 are fixed to the cover 260. The yoke 242 is formed of a magnetic plate and forms part of the magnetic circuit of the actuator 240 built in the correction lens unit 220. The structure of the actuator 240 will be described with reference to other drawings.

  FIG. 3 is a perspective view showing a state where the cover 260 is removed from the correction lens unit 220. The hatched area in FIG. 3 shows a portion that is displaced with respect to the case 250 together with the lens holding frame 232 when the actuator 240 is operated. Further, the fixing screw 262 and the flexible boards 270 and 280 in FIG. 3 are drawn in the same state as when the cover 260 is present.

  In the correction lens unit 220, a plurality of rolling balls 290 are sandwiched between the case 250 and the lens holding frame 232. The lens holding frame 232 is connected to the case 250 by a plurality of suspension springs 292. The suspension spring 292 attracts the lens holding frame 232 toward the case 250 with the rolling ball 290 interposed therebetween. Thereby, the lens holding frame 232 is held by the case 250 in a state where the lens holding frame 232 can be smoothly displaced in parallel to the case 250 without dropping the rolling ball 290.

  A pair of coils 246 and 247 are mounted on the lens holding frame 232 around the correction lens 230. The pair of coils 246 and 247 each have an oval shape. In addition, the pair of coils 246 and 247 are arranged in a direction in which the longitudinal direction thereof is orthogonal to the optical axis X, and the coils 246 and 247 are also orthogonal to each other in the longitudinal direction.

  A pair of flexible substrates 270 and 280 is attached to the lens holding frame 232. One end of the pair of flexible substrates 270 and 280 extends from the lens holding frame 232 to the outside in the radial direction of the correction lens 230 and is taken out of the lens holding frame 232.

  FIG. 4 is a front view of the correction lens unit 220 with the cover 260 removed. The hatched area in FIG. 4 indicates a portion of the flexible substrates 270 and 280 that is attached to the surface of the lens holding frame 232. As in FIG. 3, also in FIG. 4, the fixing screw 262 and the flexible boards 270 and 280 are drawn in the same state as when the cover 260 was present.

  One flexible substrate 270 located on the upper side in the drawing reaches the lens holding frame 232 from the case side fixing portion 272 through the spiral portion 276. The flexible substrate 270 in the lens holding frame 232 reaches the surface of the lens holding frame 232 along a post 238 rising from the lens holding frame 232 in parallel with the optical axis X, and rotates around the correction lens 230 clockwise and counterclockwise. Then, a pair of power feeding portions 277 and 278 extending in the radial direction of the correction lens 230 is formed through the surrounding portions 275 and 279 that respectively circulate approximately 45 degrees.

  Light emitting elements 235 and 236 such as light emitting diodes are mounted on the back surfaces of the power feeding units 277 and 278 of the flexible substrate 270, respectively. Light emitting power can be supplied to these light emitting elements from the outside of the lens holding frame 232 through the flexible substrate 270.

  The other flexible substrate 280 located on the lower side in the drawing reaches the lens holding frame 232 from the case side fixing portion 282 through the spiral portion 286. The flexible substrate 280 in the lens holding frame 232 reaches the surface of the lens holding frame 232 through a post 239 rising from the lens holding frame 232 in parallel with the optical axis X. Further, the flexible substrate 280 is connected to the coils 246 and 247 through a circulating portion 288 that rotates about 135 degrees clockwise around the correction lens 230. As a result, driving power can be supplied to the coils 246 and 247 through the flexible substrate 280 from the outside of the lens holding frame 232.

  In the lens holding frame 232 of the correction lens unit 220, a pair of coils 246 and 247 and a pair of light emitting elements 235 and 236 are disposed at an interval of approximately 90 °. As a result, the pair of coils 246 and 247 generate driving forces orthogonal to each other to displace the lens holding frame 232 two-dimensionally. In addition, the pair of light emitting elements 235 and 236 detects displacement in directions orthogonal to each other with high sensitivity, and contributes to highly accurate detection of the two-dimensional position of the lens holding frame 232 on the moving plane.

  Further, the respective spiral portions 276 and 286 of the flexible substrates 270 and 280 are arranged in an empty space between the pair of coils 246 and 247 and the pair of light emitting elements 235 and 236. As a result, the spiral portions 276 and 286 are disposed at a position that forms approximately 90 ° with respect to the optical axis X on the moving plane of the lens holding frame 232. Accordingly, the spiral portions 276 and 286 can be arranged at positions symmetrical to the horizontal line passing through the optical axis X in the drawing.

  FIG. 5 is a cross-sectional view of the correction lens unit 220, showing a state where the case 250, the cover 260, and the lens holding frame 232 are separated. 2 is a cross section obtained by cutting the correction lens unit 220 along a vertical plane passing through the optical axis X, and corresponds to a cross section at a position indicated by an arrow A in FIG.

  The lens holding frame 232 holds the light emitting element 236 on the upper side in the drawing with respect to the correction lens 230. In addition, the lens holding frame 232 has a slit 234 that narrows the light emitted from the light emitting element 236 to form a thin beam. Thereby, when the light emitting element 236 emits light, a thin beam is irradiated toward the case 250.

  The lens holding frame 232 holds one coil 246 on the lower side in the drawing with respect to the correction lens 230. The coil 246 is wound in a plane orthogonal to the optical axis X, and generates magnetic flux in the optical axis direction when driving power is supplied.

  The case 250 has an annular case substrate 254 having an opening corresponding to the correction lens 230. As a result, the correction lens 230 is exposed to the outside also on the rear side of the correction lens unit 220. A PSD 256 (Position Sensitive Detector) is mounted on the case substrate 254 at a position facing the light emitting element 236 on the lens holding frame 232 side.

  The case 250 includes a magnet 244 at a position facing the coil 246. Further, a yoke 242 is disposed on the back side of the coil 246 in the magnet 244. The yoke 242 is formed of a magnetic plate and is fixed in a state along the back surface of the magnet 244.

  The cover 260 also includes a magnet 244 at a position facing the coil 246. Further, a yoke 242 is disposed on the back side of the coil 246 in the magnet 244. The yoke 242 is also formed of a magnetic plate and is fixed to the cover 260 adjacent to the magnet 244. Alternatively, the yoke 242 fixed to the case 250 side and the yoke 242 on the cover 260 side may be fixed by caulking or the like.

  The yoke 242 provided on the cover 260 is a member that appears on the surface of the cover 260 in FIG. That is, in the cover 260, the yoke 242 penetrates the cover 260 in the thickness direction.

  FIG. 6 is a cross-sectional view of the correction lens unit 220. 6 is drawn from the same viewpoint as FIG. 5 and shows a state in which the case 250, the lens holding frame 232, and the cover 260 are assembled.

  In the correction lens unit 220, the lens holding frame 232 is sandwiched between the case 250 and the cover 260. In the lower part of the correction lens unit 220 in the figure, an actuator 240 is formed by a coil 246 and a magnet 244 sandwiching the coil 246.

  When driving power is supplied to the coil 246 through the flexible substrate 280, the actuator 240 drives the lens holding frame 232 in a direction orthogonal to the optical axis X. As a result, the correction lens 230 moves in the direction intersecting the optical axis X with respect to the case 250 and the cover 260, and the image formed by the optical system 112 is also displaced in the image sensor 122.

  In the actuator 240, the yoke 242 is disposed outside the magnet 244 with respect to the coil 246. Thereby, the magnetic field formed by the magnet 244 is prevented from leaking to the outside, and the driving efficiency of the actuator 240 is improved.

  A displacement detection unit is formed on the correction lens unit 220 by a slit 234, a light emitting element 236, and a PSD 256 (Position Sensitive Detector). The light emitting element 236 fixed to the lens holding frame 232 irradiates the narrowed beam light toward the PSD 256 located on the left side in the drawing through the slit 234.

  When the lens holding frame 232 is displaced with respect to the case 250, the irradiation position in the PSD 256 changes, so that the displacement of the lens holding frame 232 can be detected based on the change in the output of the PSD 256. Thereby, the operation of the actuator 240 can be feedback-controlled with high accuracy based on the detected displacement of the correction lens 230.

  FIG. 7 is a front view of the correction lens unit 220. A cover 260 is attached to the correction lens unit 220 again.

  In the correction lens unit 220, the spiral portions 276 and 286 of the flexible substrates 270 and 280 are oppositely wound. That is, in the illustrated example, the spiral portion 276 of the flexible substrate 270 that supplies the light emission power has a shape wound counterclockwise in the drawing from the inside to the outside. On the other hand, the spiral portion 286 of the flexible substrate 280 that supplies driving power has a shape wound clockwise from the inside toward the outside.

  As a result, when the lens holding frame 232 is displaced with respect to the case 250, if one of the flexible substrates 270 and 280 increases the urging force due to deformation, the other urging force decreases and cancels each other. Therefore, even if the displacement amount of the lens holding frame 232 changes, the change in the urging force applied to the lens holding frame 232 from the flexible substrates 270 and 280 is suppressed. As a result, the lens holding frame 232 is displaced in proportion to the drive power supplied to the actuator 240, and the image blur in the image blur correction unit 200 can be accurately corrected.

  One of the flexible substrates 270 and 280 supplies light emission power of the light emitting elements 235 and 236, and the other supplies drive power of the actuator 240. For this reason, the electrical specifications of the flexible substrates 270 and 280 are different. However, as described above, in view of the purpose of suppressing the influence of the urging force by the flexible substrates 270 and 280, the mechanical characteristics of the flexible substrates 270 and 280, that is, the elastic modulus of the substrates are uniform or at least close to each other. It is preferable.

In the above example, a combination is shown in which one flexible substrate 270 supplies light emitting power to the light emitting elements 235 and 236 and the other flexible substrate 280 supplies driving power to the coils 246 and 247. However, for example, one flexible substrate 270 supplies power to one light emitting element 236 and one coil 247, and the other flexible substrate 280 supplies power to the other light emitting element 235 and the other coil 246. You may make a combination. In this case, since the specifications of the conductor lines provided on each of the flexible boards 270 and 280 are equal, the effect of canceling out the elasticity of the flexible boards 270 and 280 becomes higher.
In the above example, the voice coil motor is described as an example of the actuator 240. However, the driving element is not limited to the voice coil motor as long as it can drive the correction lens 230. Further, the detection element is not limited to the light emitting element 236 and the PSD 256 as long as the position of the correction lens 230 can be detected.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Imaging device, 110 Lens barrel, 112 Optical system, 120 Camera body, 122 Image sensor, 200 Image blur correction part, 210 Detection part, 212, 214 Acceleration sensor, 220 Correction lens unit, 230 Correction lens, 232 Lens holding frame 234 slit, 235, 236 light emitting element, 238, 239 post, 240 actuator, 242 yoke, 244 magnet, 246, 247 coil, 250 case, 252 fixing pin, 254 case substrate, 256 PSD, 260 cover, 262 fixing screw, 263, 265 passage hole, 264 central opening, 270, 280 flexible substrate, 272, 282 case side fixing part, 274, 284 holding frame side fixing part, 275, 279, 288 orbiting part, 276, 286 spiral part, 77,278 power supply section, 290 rolling ball, 292 suspension springs

Claims (6)

A correction lens for correcting image blur in the optical system;
A correction lens holding frame for holding the correction lens;
A fixed support portion that supports the correction lens holding frame so as to be movable on a moving plane that intersects the optical axis of the optical system;
A driving element that is fixed to the correction lens holding frame and that is supplied with electric power to generate a driving force for driving the correction lens;
A detection element fixed to the correction lens holding frame and supplied with electric power to be used for detecting the position of the correction lens holding frame;
A first flexible unit that supplies power to the driving element while elastically deforming between a first fixing unit fixed to the fixing support unit and a second fixing unit fixed to the correction lens holding frame. A substrate,
It is attached when the urging force of the first flexible substrate is increased due to elastic deformation between the third fixing portion fixed to the fixing support portion and the fourth fixing portion fixed to the correction lens holding frame. When the urging force is reduced and the urging force of the first flexible substrate is reduced, the urging force is increased, thereby suppressing the change of the urging force applied to the correction lens holding frame and supplying power to the detecting element. 2 flexible substrates,
The driving element includes a first coil that moves the correction lens holding frame in a first direction on the moving plane, and the correction lens holding frame in a second direction that intersects the first direction on the moving plane. A second coil to be moved,
On the moving plane, the direction of the urging force of the first flexible substrate and the direction of the urging force of the second flexible substrate are axisymmetric with respect to the second direction.   The fixed support portion includes a cover portion that covers the driving element and the detection element, and the first flexible substrate has the first fixed portion fixed to the outside of the cover portion, and is provided on the cover portion. The second flexible substrate is fixed to the third fixing part on the outer side of the cover part, and the second flexible substrate is connected to the detection element through another through hole provided in the cover part. The optical apparatus according to claim 1, wherein the optical apparatus is coupled to the element. The driving element includes a first coil that moves the correction lens holding frame in a first direction on the moving plane, and the correction lens holding frame in a second direction that intersects the first direction on the moving plane. A second coil to be moved,
The detection element includes a first element that is displaced when the correction lens holding frame is moved in the first direction, and a second element that is displaced when the correction lens holding frame is moved in the second direction. ,
The first flexible substrate supplies the power to the first coil and the second coil by fixing the second fixing portion to the correction lens holding frame between the first coil and the second element. ,
The second flexible substrate has the fourth fixing portion fixed to the correction lens holding frame between the first element and the second element, and supplies the power to the first element and the second element. The optical apparatus according to claim 1 or 2. The driving element includes a first coil that moves the correction lens holding frame in a first direction on the moving plane, and the correction lens holding frame in a second direction that intersects the first direction on the moving plane. A second coil to be moved,
The detection element includes a first element that is displaced when the correction lens holding frame is moved in the first direction, and a second element that is displaced when the correction lens holding frame is moved in the second direction. ,
The first flexible substrate supplies the power to one of the first coil and the second coil and one of the first element and the second element,
The optical apparatus according to claim 1, wherein the second flexible substrate supplies the electric power to the other of the first coil and the second coil and the other of the first element and the second element. The first flexible board has a spiral-shaped portion wound in one of a clockwise direction and a counterclockwise direction so that the biasing force is generated in the radial direction of the correction lens, and the first fixing part and the second fixing part. Between the part and
In the second flexible substrate, the third fixing portion and the fourth fixing portion are formed in a spiral shape wound around the other clockwise or counterclockwise so that an urging force is generated in the radial direction of the correction lens. The optical apparatus according to any one of claims 1 to 4, further comprising:   The direction of the urging force generated by the elastic deformation of the first flexible substrate and the direction of the urging force generated by the elastic deformation of the second flexible substrate form an angle of approximately 90 degrees on the moving plane. The optical device according to claim 5.

Images