JPH0384506A - Blurring correcting lens barrel - Google Patents

Abstract

PURPOSE:To obtain a blurring correcting lens barrel which reduces a driving load on zooming and focusing and provides a feeling of light operation by providing permitting means which permit a blurring correcting lens holding frame to move in the direction of the optical axis to driving force transmitting mechanisms which transmit a driving force from a driving means to a blurring correcting lens. CONSTITUTION:The driving means 29 which generates the driving force for moving the blurring correcting lens 11 at right angles to the optical axis of a photographic optical system is fitted to the fixed cylinder 2 of the blurring correcting lens barrel and the driving force transmitting mechanisms 20, 21, 24 and 25 for transmission from the driving means 29 to the blurring correcting lens 11 are provided with the permitting means 20 and 24 which permit the blurring correcting lens holding frame 9 to move in the direction of the optical axis. Thus, the driving means for the blurring correcting lens is fitted to the fixed cylinder and then the driving means is prevented from moving together with the blurring correcting lens at the time of zooming and focusing. Consequently, the driving load on the zooming and focusing is reduced correspondingly.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a camera lens barrel having a correction lens movable in a direction perpendicular to an optical axis in order to correct image blur such as camera shake.

[Conventional technology]

2. Description of the Related Art A blur correction lens barrel is known that corrects and suppresses image blur by moving some of the lenses constituting a photographic lens in a direction perpendicular to the optical axis. Generally, when performing zooming or focusing in a vibration reduction lens barrel, the correction lens must also be moved in the optical axis direction, and in conventional image stabilization lens barrels, the drive mechanism is mounted on the movement frame of the correction lens. Many are designed to be easily compatible with zooming and focusing mechanisms. However, although mounting the correction drive mechanism on the correction lens moving frame in this way does not affect the optical operation of the zooming and focusing mechanisms, it does not affect the dynamic performance of the image stabilization drive mechanism, including the vibration reduction drive mechanism. Since the correction lens is moved, the driving load thereof increases, and particularly in the case of an autofocus mechanism, the load on the drive motor increases and its response speed becomes slow.

[Problem to be solved by the invention]

The present invention has been devised in view of the above-mentioned conventional technical problems and to effectively solve them. Therefore, an object of the present invention is to prevent the correction lens from moving along with the movement of the zooming mechanism or focusing mechanism during zooming or focusing, but without causing the correction drive mechanism of the correction lens to follow the movement. It is an object of the present invention to provide a shake correction lens barrel which reduces the driving load of zooming and focusing and realizes a light operational feeling.

[Means to solve the problem]

The image stabilization lens barrel according to the present invention solves the problems of the prior art as described above, and has the following configuration in order to achieve the object. First of all, the image stabilization lens barrel according to claim 1 is a image stabilization lens barrel equipped with an image stabilization lens that can be adjusted and moved in a direction perpendicular to the optical axis of a photographing optical system in order to correct camera shake during photographing.
A driving means for generating a driving force for moving the image stabilization lens in a direction perpendicular to the optical axis of the photographic optical system is attached to a fixed barrel of the image stabilization lens barrel, and a driving force from the drive means to the image stabilization lens is attached to the fixed barrel of the image stabilization lens barrel. The transmission mechanism is provided with a permitting means for permitting movement of the blur correction lens holding frame in the optical axis direction. Further, in the image stabilizing lens barrel according to claim 2, the above-mentioned allowing means is connected to a driving means, is rotated around an axis, and is engaged with a guide bar having a non-circular cross section and extending in the optical axis direction. The transmission means is movable in the optical axis direction together with the image stabilization lens holding frame along the guide bar, and provides movement of the image stabilization lens perpendicular to the optical axis.

[Action and effect of the invention]

In the image stabilization lens barrel according to the present invention, the allowing means included in the driving force transmission mechanism that transmits the driving force to the image stabilization lens in order to perform image stabilization is configured to move the image stabilization lens holding frame in the optical axis direction. The driving force is transmitted regardless of movement. Therefore, the distance in the optical axis direction between the image stabilization lens and its driving means is variable without changing the driving system. The movement of the blur correction lens in the optical axis direction can respond to the movement of the main lens group in the optical axis direction. As a result, the drive means for the image stabilization lens can be attached to a fixed tube, so even the drive means does not move together with the image stabilization lens during zooming and focusing, reducing the driving load for zooming and focusing. It becomes possible to reduce the amount by that amount. It also makes it easier to operate when zooming or focusing.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 15. In the present embodiment shown in FIG. 1, the operation when zooming is performed will be explained. When the zoom operation ring 3 provided on the outermost periphery of the lens barrel is rotated, the rotation is transmitted to the zoom cam ring 6 via the guide pin 44 engaged with the operation ring 3, and this zoom cam ring 6 rotates. . A spiral cam groove 6a is formed in the zoom cam ring 6. On the other hand, a straight groove 2a is formed in the fixed barrel 2 in the optical axis direction, passing through the fixed barrel 2 in its thickness direction. The first and fourth group moving frames 7 are disposed on the inner circumferential side of the fixed cylinder 2.
A guide pin 45 is disposed on the outer peripheral surface of the movable frame 7 and protrudes outward in the radial direction, penetrates the straight groove 2a of the fixed barrel 2, and engages with the cam groove 6a of the zoom cam ring 6. It is set up. Therefore, by rotating the zoom cam ring 6,
The first and fourth group moving frames 7 perform rectilinear movement in the optical axis direction. By a mechanism completely similar to this, the second group moving frame 8 and the blur correction lens holding frame 9 move linearly in the optical axis direction. 2b is a rectilinear groove formed in the fixed barrel 2, 6b and 6c are cam grooves of the zoom cam ring 6, 46 is a guide pin that projects from the second group moving frame 8 and engages with the cam groove 6b, and 47 is a shake correction This is a guide pin that projects from the lens holding frame 9 and engages with the cam groove 6c. As each moving frame 7.8 and holding frame 9 move in a straight line, a drive lever 20 (see FIG. 2) and an interlocking lever 24, which will be described later, remain integral in the rotational direction and are guided by the long groove 20a to guide the optical axis. The correction lens holding frame 9 is slid in the optical axis direction without interfering with the movement of the correction lens holding frame 9 in the optical axis direction. Next, in this embodiment shown in FIG. 1, auto focusing (AF)
This will be explained in the case of Due to the driving force from the camera body,
AF coupler 41 rotates. This rotation is caused by the AF gears 42 and 43 and the focus operation ring 4.
The focus operation ring 4 is decelerated by the inner gear 4a of
Rotate. A straight groove 4b extending in the optical axis direction is formed in approximately the front half of the inner circumferential surface of the focus operation ring 4. And just inside facing the inner peripheral surface is the focus lens frame 5.
is located. A guide pin 48 is provided protruding from the outer circumferential surface of the focus lens frame 5, and is used to guide the focus operation ring 4 in a straight line F? 4b. Therefore, the rotational force of the focus operation ring 4 is directly transmitted to the focus lens frame 5, and the frame 5 rotates together with the operation ring 4 in such a manner that movement of the frame 5 relative to the operation ring 4 in the optical axis direction is permitted. As shown in the figure, the threaded portion 5a of the focus lens frame 5 and the first and fourth group moving frames 7
Since the focus lens frame 5 is screwed together with the threaded portion 7a, rotation of the focus lens frame 5 causes a screw movement relative to the first and fourth group moving frames 7.
Focusing is performed by extending and retracting the focus lens frame 5. In addition, in the case of manual focusing, the driving force transmission system (not shown) from the camera body side driving force to the AF coupler 41 is disconnected by switching between auto and manual, and the rotation of the focusing operation ring 4 is manually performed. It will be done. 1 to 4 show a lever drive type blur correction drive mechanism as a first embodiment. The vibration reduction lens holding frame 9 is fitted with a vibration reduction lens frame 10 for holding the vibration reduction lens 11 provided closest to the object side in the lens group. It is sandwiched between vertical and mutually opposing surfaces 9a and 9b, and is movable in the direction perpendicular to the optical axis, but movement in the optical axis direction is restricted. Figure 2 shows the image stabilization lens 11 in Figure 1.
FIG. 4 is a diagram showing the relationship between the image stabilization lens holding frame 9, the image stabilization lens frame 10, and other peripheral mechanisms as viewed from the objective side. The lens frame 10 has press pins 21X, 21 that protrude vertically (X direction) tJk (X direction) and penetrate the lens holding frame 9.
y (the correction mechanism in the X direction is represented by adding X to the reference number, and the correction mechanism in the X direction is represented by adding y to the reference number) and biasing plate 2
2x and 22y are provided in contact with each other, and the biasing plate 22x
, 22y are pressed by their respective heads or leaf springs 23 to be biased in the X direction and the X direction. On the other hand, press bottle 21X. The tip of the lens 21y is pressed in a direction opposite to the biasing direction of the temporary spring 23 by the drive levers 20x and 20y, thereby positioning the lens frame 10. FIG. 3 shows a drive motor 29, an interlocking gear 25
．． 26.27, one set of the light shielding plate 30, and the photointerrupter 31 is shown, but one set of this system is provided in each of the X direction and the X direction. Drive motor 29
When is driven, the interlocking lever 24 rotates via the interlocking gears 25, 26, 27. Since the interlocking lever 24 is engaged with the drive lever 20 held by the shake correction lens holding frame 9 through the long groove 20a, the drive lever 20 also rotates as the interlocking lever 24 rotates, and the pressing bottle 2■ is pushed in. . For example, when the press bottle 21x in the X direction is pushed in, the shake correction lens frame 10
moves in the X direction against the urging force of. At this time, regarding the press bottle 21y and the biasing plate 22y in the X direction, the contact surface of the shake correction lens frame 10, which the press bottle 21y and the bias plate 22y contact, is formed into a plane parallel to the X direction. , the image stabilization lens frame ■0 can be slid. When the rotation direction of the drive motor 29 is reverse rotation, the interlocking lever 24 and the drive lever 20 also rotate in the reverse direction, and the blur correction lens frame 10 also moves in the opposite direction in the X direction. The same applies to the correction operation in the X direction. As described above, the structure for driving the image stabilization lens frame 10 in the X direction or in the By adopting the push-in configuration, the backlash of the gear part in the drive force transmission mechanism can be constantly absorbed, and the correction operation of the shake correction lens frame 10 that follows the operation of the drive mechanism is
Since there is no play, the accuracy of the movement can be improved. The drive motor 29 is a pulse motor, and as shown in FIG. 3, its rotation is transmitted to the interlocking lever 24 through interlocking gears 27, 26, and 25 at high speed. The reduction ratio is set so that the gear 25 does not rotate more than 3600 degrees even if the shake correction lens frame +0 is driven full stroke. Further, a light shielding plate 30 is fixed to the gear 25 coaxially therewith. By rotating in synchronization with the gear 25, the light shielding plate 30 creates a slit in one place that allows the light of the photointerrupter 31 to pass through and obtains its output only when the shake correction lens frame 10 is at the center of the optical axis. We are prepared. Therefore, by rotating the pulse motor 29 in the reverse direction after driving the vibration reduction lens frame 10 and stopping the pulse motor 29 at the position where the output of the photo interrupter 31 is, the vibration reduction lens frame IO is moved to the initial position where the correction amount is 0. can be restored to. Figure 4a shows photo interrupter 3
1 and the slit of the light shielding plate 30 are deviated by an angle θ, and FIG. 4b shows a state where the position of the photointerrupter 31 and the slit match. FIG. 5 shows a multi-rotation cam type as a second embodiment of the shake correction drive mechanism. In the second embodiment, the interlocking lever 24. and the drive cam 202 are connected by a so-called "oval connection (column guide)". That is, at the joint,
The interlocking lever 242 has a non-circular cross section such as an ellipse or an oval shape, and the interlocking lever 24. For the rotation of the drive cam 20. rotates integrally, but axial sliding is allowed. Drive cam 20. The cam profile has a spiral stepped cam profile formed around its center of rotation, and its radial dimension changes smoothly along the axial direction. Cam follower 21. has one end in contact with the cam profile, and the image stabilization lens holding frame 9. The other end is the image stabilizing lens frame 10. is in contact with. The blur correction lens frame 102 receives an urging force from the opposite side in the radial direction, as in the first embodiment. A male screw 20a is formed at the tip of the drive cam 202, and a female screw 12 is formed at the tip of the shake correction lens holding frame 92.
By screwing into the drive cam 20.2, the interlocking lever 24° rotates and the drive cam 20. moves in the optical axis direction, and the cam follower 2h moves according to the cam profile. the result,
The position of the shake correction lens frame is adjusted by moving it 10 degrees in the radial direction. The pitch of this male screw 20a is
It is the same as the pitch of the helix in the cam profile. FIGS. 6 and 7 show a screw type as a third embodiment of the shake correction drive mechanism. In the third embodiment, the interlocking lever 2
43, a helical gear 613 is connected in an oval manner. A helical gear 363 that changes the rotation direction by 90 degrees is screwed into the gear 6t. The direction of the rotation axis of the gear 363 is perpendicular to the optical axis of the photographic optical system. The gear 363 has a drive shaft 35. The driving shaft 353 has a male threaded portion 35a3 formed approximately at its center, and the sheath member 343 is screwed together with a female threaded portion 34a3 so as to surround the male threaded portion 35a3. The sheath member 343 is fixed to a cover member 133 fixedly attached to the tip of the shake correction lens holding frame 93. Further, although the gear 363 is fitted to the top of the sheath member 343, the gear 363 can freely rotate relative to the sheath member 343. Therefore, when the drive motor rotates, the interlocking lever 243, gear 61. and 363, and the rotation is transmitted to the drive shaft 353, and the rotation of the drive 1lII 353 is transmitted to the sheath member 3.
The position of the blur correction lens frame 103 can be adjusted by moving it in the axial direction from the screw engagement with the lens frame 43. The blur correction lens frame i0a includes an inner flange portion 323 of the cover member 133,
It is held between inner flange portions 333 formed at the tip of the blur correction lens holding frame 93. Image stabilization lens frame 10
゜ is similar to the first embodiment and the other embodiments, but receives an urging force from the opposite side in the radial direction. therefore,
When the operation of the drive shaft 353 becomes high speed, the lens frame 10. There is a possibility that the movement of As a countermeasure,
Shake correction lens frame 10° and shake correction lens 11. It is possible to reduce the weight of the motor and increase the biasing force, but increasing the biasing force increases the load on the drive motor, which is not preferable. Therefore, when trying to reduce the weight of lenses and lens frames, it is common practice to make them plastic, but there are concerns about their durability against sliding and impact. Therefore, in this embodiment, as shown in FIG. 7, steel balls 383 and metal sliding plates 39 as and 39 ba are used.
By using , it is possible to reduce weight and improve durability. In addition, 37. is a retainer for steel balls 383. In particular, the structure on the side that biases and supports the image stabilization lens frame lO3 is
As shown in Fig. 6, planes parallel to the X direction and the y direction are formed on the support portion of the lens frame lO3, and the steel ball 143 is inserted along these planes as shown in Fig. 9.10. Approximately 1-shaped biasing plates 22 that are held in an arrayed state
．． , and a compression coil spring 233 is attached to the vertical bar part.
It is constructed by fitting. In this embodiment, the drive shaft 353
The lower end of the is formed into a spherical surface, but in order to further reduce the friction at that part, a steel ball 38''3 may also be provided at the tip, as shown in FIG. 8. In the third embodiment described above, the drive shaft 353 moves in the axial direction while rotating, but by adopting the structure shown in FIG. 11 as the fourth embodiment, the drive shaft 354 does not rotate in the screw type. Specifically, the drive shaft 354 is connected to the sheath member 344 fixed to the cover member 134, and the drive shaft 354 is connected to the sheath member 344 fixed to the cover member 134. The gear 364 and the drive shaft 354 are screwed together. The helical gear 364 is rotatable with respect to the sheath member 344. FIGS. 12 and 13 show a fifth embodiment of the shake correction drive mechanism. shows a grooved cam type. In this embodiment, a disk member having a spiral grooved cam 15. is attached to the tip of the interlocking lever 24. The cam profile of the grooved cam 15. is similar to that of the interlocking lever 24. The drive shaft 35 serves as a cam follower.
The tip of 6 is engaged with this cam groove. The other end of the drive shaft 35° is the vibration reduction lens frame 10. The intermediate portion thereof is in contact with the shake correction lens holding frame 9° or its cover member 13. Only axial movement is permitted and maintained through the . Therefore, the interlocking lever 24° and the disk member are rotated by the operation of the drive motor, and the spiral grooved cam 15. and drive shaft 35. The drive shaft 355 moves in the axial direction due to the engagement with the image stabilizing lens frame 1o,
The position is adjusted. 14 and 15 show the sixth and seventh parts of the shake correction drive mechanism.
A ball screw type is shown as an example. This type has a sheath member 34° and a drive shaft 35. This can be achieved by using a ball screw to engage the helical gear 364 and the drive shaft 354 in the fourth embodiment. 16 in each figure. 1 and 167 are steel balls; 17° and 167 are spiral V-shaped grooves formed on the outer peripheral surface of the drive shaft; 18. and 18. is steel ball 16. , , into the V-shaped groove 17. ．． 7 is a spring member that presses into the inside. Note that with the ball screw type, there is no need to provide a slip structure to protect the mechanism when the drive range is pushed all the way to the end. In each of the above-mentioned embodiments, in order to disclose as many variations of each component as possible, some parts are shown differently for each embodiment. Of course, the combinations thereof may be changed.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the image stabilization lens barrel according to the present invention, and FIG. FIG. 3 is a schematic diagram showing the structure of the vicinity of the drive means of the shake correction drive mechanism in the shake correction lens barrel according to the present invention. FIG. 4 is a diagram illustrating the operating state of the position detection mechanism in the shake correction drive mechanism of FIG. 3. FIG. 5 is a longitudinal sectional view showing a multi-rotation cam type as a second embodiment of the shake correction drive mechanism. FIG. 6 is a front view showing a screw type as a third embodiment of the shake correction drive mechanism, FIG. 7 is a sectional view of the main part of the third embodiment,
FIG. 8 is a sectional view of a main part of a partial modification of the third embodiment of the image stabilization mechanism, and FIG. 9 is a longitudinal sectional view showing the steel ball structure on the side that urges and supports the image stabilization lens frame in the third embodiment. , FIG. 10 is a bottom view of FIG. 9. FIG. 11 is a sectional view of a main part showing another example of the screw type as the fourth embodiment of the shake correction mechanism. FIG. 12 is a diagram showing a grooved cam type spiral grooved cam as a fifth embodiment of the shake correction mechanism, and FIG. 13 is a schematic diagram showing the state of engagement between the grooved cam and the drive shaft of the fifth embodiment. FIG. 14 is a schematic diagram showing an example of a ball screw type as the sixth embodiment of the shake correction mechanism;
FIG. 5 is a schematic diagram showing another example of the ball screw type as the seventh embodiment of the shake correction mechanism. 2... Fixed tube, 11... Shake correction lens, 29...
- A drive motor as a drive means, 20... A drive lever 21 that constitutes a part of the drive force transmission mechanism and is a permitting means.
...Press pin 24 forming part of the driving force transmission mechanism
... An interlocking lever that constitutes a part of the driving force transmission mechanism and is a permitting means, 25, 26. 27... An interlocking gear that constitutes a part of the driving force transmission mechanism, 34... A driving force transmission mechanism A sheath member constituting a part of 35... A drive shaft constituting a part of a driving force transmission mechanism, 36.61 A helical gear constituting a part of a driving force transmission mechanism and serving as a permitting means.

Claims (2)

[Claims] (1) A shake correction lens that can be adjusted and moved in a direction perpendicular to the optical axis of the photographic optical system to correct camera shake during shooting (
11), a driving means (29) for generating a driving force for moving the image stabilization lens (11) in a direction perpendicular to the optical axis of the photographic optical system is provided in the image stabilization lens barrel. A driving force transmission mechanism (20, 21, 24, 25, 26, 27) is attached to the fixed barrel (2) and transmits the driving force from the driving means (29) to the shake correction lens (11).
, 34, 35, 36, 61) are provided with a permitting means (20) for permitting movement of the shake correction lens holding frame (9) in the optical axis direction.
, 24, 36, 61). (2) The above-mentioned permitting means (20, 24) is the driving means (29).
), the guide bar (24) is rotated around the axis and has a non-circular cross section and extends in the optical axis direction; The transmission means (20, 36, 61) is movable in the optical axis direction together with the image stabilization lens holding frame (9) and provides movement perpendicular to the optical axis to the image stabilization lens (11). The image stabilization lens barrel according to item 1.