JP3372730B2 - Lens barrel and camera - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel having a correction lens for correcting image blur by moving in a direction other than the optical axis of a photographing optical system, and a camera integrally provided with the lens barrel. Related to the improvement of.

[0002]

2. Description of the Related Art In recent years, for the purpose of correcting camera shake caused by camera shake or the like, a shake correction device for canceling the shake by moving a part of the photographing optical system (correction lens) in a direction different from the optical axis has been available. Various proposals have been made and commercialized.

As an actuator for driving the correction lens, a moving coil system is used in terms of frequency characteristics and driving accuracy.

When the moving coil system is used as the actuator, as shown in Japanese Patent Application Laid-Open No. 4-34513, the lock is rotated only when the shake correction is not performed, that is, when no current is applied to the coil. A mechanism is required to hold the correction lens at a predetermined position such as a movable center by driving the lock member and engaging the lens barrel having the correction lens.

More specifically, when the electromagnetic motor is used as the actuator, the correction lens does not move due to the holding torque of the motor itself even if the power is turned off. However, in the moving coil system, the correction lens is turned off. Therefore, in order to protect the apparatus, a dedicated locking device for locking the correction lens at a predetermined position as described above is required in addition to the actuator for correcting the shake.

As another conventional example, JP-A-5-100
As indicated by No. 280, a pin that advances and retreats in conjunction with the collapsing operation of the lens barrel is configured to lock the correction lens by engaging with a hole provided in the correction lens frame. It is also known that an actuator is unnecessary.

[0007]

However, there is a strong demand for further downsizing and cost reduction of the lens barrel and the camera while having the added value of shake correction, and these are impeded by the arrangement of the locking device. Not a few things.

For this reason, in the conventional example disclosed in Japanese Patent Laid-Open No. 4-34513, a mechanism and an actuator dedicated to the lock are required, and the lock device increases the size and cost of the entire lens barrel and consumes it. There was a problem that the power also increased.

Further, in the conventional example shown in Japanese Patent Laid-Open No. 5-100280, a dedicated actuator is not required, so that power saving and compactness are realized, but a pin for locking and a coil spring are required. There was a problem that the mechanism for locking was complicated.

(Object of the Invention) An object of the present invention is to eliminate the need for a structural member for functioning the locking means for locking the correction lens, and to achieve a compact lens barrel and a lens barrel. To provide a camera.

[0011]

In order to achieve the above-mentioned object, the present invention provides a focus driving member with an engaging portion for disabling movement of a correction lens for image shake correction, and Locking means is provided for locking the correction lens at a predetermined position by engaging with the engaging portion when the member moves beyond the photographic range.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on the illustrated embodiments.

FIG. 1 is a cross-sectional view showing the structure of a zoom lens barrel according to an embodiment of the present invention. A TELE (telephoto) state is shown in the upper part of the figure and a WI is shown in the lower part around the optical axis.
The DE (wide angle) state is shown.

In FIG. 1, an exterior ring 2 is fixed to the rear portion of the fixed barrel 1 with screws, and a cam barrel 4 is held on the outer periphery so that it can rotate only in a fixed position (the cam barrel 4 and the fixed barrel). 1
Is shown in FIG. 2). At the rear of the outer ring 2,
A mount 3 to which a camera body (not shown) is mounted is fixed by screws.

On the front side of the straight-moving barrel 5, a first-group barrel 6 holding a first-group lens L1 and a filter frame 7 are fixed by screws. Also, on the rear side, there are three locations in the circumferential direction, the key 5a
Are fixed by screws 5b, and the key 5a is engaged with the rectilinear groove 1a of the fixed barrel 1 and the first group cam 4a of the cam barrel 4.

Reference numeral 8 denotes a third group lens barrel holding a third group lens L3, to which a known diaphragm unit 9 is fixed. Also,
The third group lens barrel 8 is a fifth group lens barrel 1 holding a fifth group lens L5.
It is fixed by 0 and a screw (not shown), and is configured to integrally move the third and fifth lens groups L3 and L5. Rollers 10a are attached to the fifth-group lens barrel 10 at three locations by screws, and the rollers 10a are engaged with the straight groove 1b of the fixed barrel 1 and the third and fifth-group cams 4b of the cam barrel 4. .

Reference numeral 11 denotes a fourth-group lens barrel holding a fourth-group lens L4, which holds rollers 11a at three positions. And
The roller 11 a is engaged with the rectilinear groove 1 c of the fixed barrel 1 (in FIG. 1, for simplification, 1 a and 1 c are shown in the same plane) and the fourth group cam 4 c of the cam barrel 4.

That is, when the cam barrel 4 is rotated for the zoom operation, the lenses L1 and L of the first, third, fourth, and fifth groups are formed.
3 to L5 move in the optical axis direction (the lenses L3 and L5 of the third group and the fifth group move together).

Reference numeral 12 denotes a second fixed cylinder, and the rear portion thereof is the fixed cylinder 1.
The ultrasonic motor 13 is held on the outer circumference. Although the principle of the ultrasonic motor 13 is well known and omitted, the rotor 13a is driven to rotate at a fixed position. Reference numeral 14 denotes an output ring, which is rotatably held in a fixed position. Rollers 14a are held at three positions on the outer circumference of the output ring 14, and 14a is held rotatably around a shaft 14b protruding in the radial direction.

Reference numeral 15 denotes a manual ring, which is rotatably held in a fixed position. The roller 14a and the manual ring 15 are sandwiched between the rotor 13a and the second fixed cylinder 12, and the output ring 14 is rotationally driven at a half rotation angle with respect to the rotor 13a by a mechanism similar to the retainer in the bearing. It Also, the manual ring 15
Even if is rotated, it will be rotated at a half rotation angle by the same mechanism.

Reference numeral 16 denotes a zoom ring, which is the second fixed barrel 1.
It is held rotatably at a fixed position by connecting a bayonet to the front end of 2. Reference numeral 17 denotes a connecting plate for connecting the cam barrel 4 and the zoom ring 16, one end of which is fixed to the cam barrel 4 with a screw and the other end of which is fixed with a step screw 17a. I am trying to rotate.

Reference numeral 18 denotes an intermediate cylinder, a key portion 18a provided on the rear portion is engaged with a straight groove 16a on the inner periphery of the zoom ring 16, and a protruding cam 18b having a lead provided on the inner periphery is a cam follower of the filter frame 7. 7b is engaged. In the present embodiment, when the zoom ring 16 is rotated, the filter frame 7 moves straight, and the intermediate cylinder 18 sets the lead of the protruding cam 18b so as to rotationally feed out about half the amount thereof.

Next, the shake correction unit according to the present invention will be described.

In FIG. 1, the second group lens L2 is a correction lens for correcting shake (also serves as a focus adjustment lens).
And is configured to correct the camera shake by moving in the direction perpendicular to the optical axis. Reference numeral 50 denotes a shake correction unit that drives the second lens group L2, which is a correction lens, for shake correction, and is arranged in a donut shape around the second lens group L2.

FIG. 3 is a cross-sectional view showing details of the correction unit 50 and a focus adjusting structure which will be described later. In FIG. 3, reference numeral 51 denotes a base plate, and a foot 51a protruding at three places on the rear portion has rollers 51b. The fixed cylinder 1 is provided by engaging the roller 51b with the hole 1d (see FIG. 1) of the fixed cylinder 1.
Holds together with. Reference numeral 52 is a yoke made of a metal plate, and two magnets 53 are bonded and fixed in the radial direction and fixed to the base plate 51 with screws (not shown). Reference numeral 54 denotes a coil, which is attached to the outer periphery of the shift frame 55 so as to be wound in a plane perpendicular to the optical axis. Reference numeral 56 is a yoke similar to 52, and is fixed to the main plate 51.

Reference numeral 57 denotes an IRED, which is fixed to the shift frame 55. Reference numeral 58 represents PSD, which is the IRED57.
The amount of movement of the shift frame 55 is detected by receiving the infrared light projected from the. The PSD 58 is mounted on a substrate 59, and the substrate 59 is fixed to the base plate 51.

Here, the shift frame 55 with respect to the main plate 51,
It can be moved in any direction perpendicular to the optical axis. That is, the above-mentioned driving means (including the yokes 52 and 56, the magnet 53, and the coil 54) and the position detecting means (IR
ED57 and PSD58) are described with respect to movement in one direction (here, the vertical direction), but similar members are also arranged in the direction perpendicular to this (horizontal direction).

The inner periphery of the shift frame 55 is a second lens group L2.
Is fitted to the outer periphery of the second group lens barrel 19 holding the. Also,
By engaging the key portion 55a on the inner circumference of the shift frame 55 and the straight-moving groove 19a on the outer circumference of the second group lens barrel 19, it is possible to move only in the optical axis direction.

Reference numeral 20 denotes a focus ring, the front surface of which is a disc-like shape provided with a light-shielding line, and the foot portion 20a extending rearward on the outer periphery.
Are provided in three equal parts in the circumferential direction. The legs 20a are fitted to the outer circumference of the cam barrel 4, and the focus rollers 20
b is fixed (press fit in this example). The focus roller 20b is engaged with the focus cam 4d of the cam barrel 4, and is rotated in the optical axis direction by rotating the focus ring 20. The focus roller 20b is engaged with the key 21 fixed to the output ring 14 driven by the ultrasonic motor 13 described above.

On the other hand, a pressing plate 21 is fixed to the back surface of the focus ring 20 with screws,
The sliding surface 20c and the holding plate 21 of the collar 19b of the second group lens barrel 19
The second group lens barrel 19 is held movably in the radial direction with respect to the focus ring 20.

Returning to FIG. 1, reference numeral 22 denotes a donut-shaped mounting substrate, which includes the ultrasonic motor 13, the electromagnetic diaphragm unit 9, and the coil 54, IR in the shake correction unit 50 described above.
It is electrically connected to the ED 57 and PSD 58 (not shown). In the correction unit 50, the coil 54, IRED5
First, the wiring 7 is connected to the board 59, and the board 59 is connected to the mounting board 22 by one flexible printed board.

Reference numeral 23 denotes a vibration gyro that is a shake detection sensor attached to the mounting substrate 22, and includes a fixed cylinder 1 and a second cylinder.
A part of the fixed barrel 12 is cut out, and two pieces are arranged so as to change the direction by 90 degrees around the optical axis so as to detect shake in the vertical direction and the horizontal direction. Reference numeral 24 denotes a contact part, which is attached to the mount 3 to receive communication with a camera body (not shown) and supply of power. Reference numeral 25 is a back cover attached for the purpose of protecting the inside of the substrate 22 and preventing the visibility.

Next, the operation will be described.

In the lens barrel according to the present embodiment, the first group and fourth group lenses L1 and L4 move independently and the third group and fifth group lens L3 and L5 move integrally by a zoom operation. Further, as shown in FIG. 2, the second group lens L2 slightly moves so as to correct the focus position by the focus cam 4d.

When the focusing operation is performed, the ultrasonic motor 1 is operated based on the signal from the AF sensor of the camera body.
3 is driven or the manual ring 15 is rotated to manually adjust the focus, the output ring 14 rotates, and the focus ring 4 moves by the focus cam 4d in the optical axis direction while rotating.

Here, the feeding amount from infinity to the closest distance changes depending on the zoom position, and the amount on the TELE side becomes larger (see FIG. 2). Since the second group lens barrel 19 is movable in the optical axis direction with respect to the shift frame 55 and immovable in the optical axis direction with respect to the focus ring 20, the focus ring 20 is moved in the optical axis direction. The focus is adjusted by moving the same amount as the amount in the optical axis direction.

Regarding the shake correction operation, first, the shake amount of the camera is detected by the vibration gyro 23, and the eccentric amount of the second group lens L2 for canceling the shake is detected.
The calculation is performed by the microcomputer in 2, and the shift frame 55 of the shake correction unit 50 is driven by the moving coil method. The movement amount of the shift frame 55 is detected by the IRED 57 and the PSD 58, and the detection signal is fed back to perform highly accurate shake correction. The principle of detecting the shake, the calculation, and the driving direction are well-known techniques, and detailed description thereof will be omitted.

The amount of eccentricity of the shift frame 55 is integrally transmitted to the diameter-fitted second group lens barrel 19. At this time, the second group lens barrel 19
Is held movably with respect to the focus ring 20 only in the shift direction, so that it is possible to perform shake correction by moving in the shift direction while keeping the position in the optical axis direction constant, that is, while maintaining the in-focus state. is doing.

Next, a method of locking the second lens group L2, which is a correction lens, when the photographing is not performed will be described.

FIG. 4 is a view for explaining the lock operation, and more specifically, it is a plan view of the holding plate 21 and the second group lens barrel 19 attached to the back surface of the focus ring 20 as seen from the mount side.

FIG. 4 shows the locked state. The projections 19c provided at three locations on the outer circumference of the second group lens barrel 19 come into contact with the inner peripheral projections 21a of the holding plate 21, so that the second group lens barrel 19 moves in the shift direction. It prevents them from moving. In this state, the focus ring 20 is rotated from the infinite position by a predetermined angle to the outside of the photographing range.

When the press ring 21 is rotated together with the focus ring 20 in the direction of A in the drawing for photographing, the contact between the projection 19c and the inner peripheral convex portion 21a of the press plate 21 is released at the infinite position, and the projection 19c is free from space. 21b, the second group lens barrel 19 is in a shiftable state. The space 21b has an angular range that secures a clearance that allows shift movement while being rotated from infinity to the closest distance.

The present lens barrel is controlled so as to drive the focus ring 20 to the lock position (super-infinite position) and lock the correction lens when the photographing is not performed. That is, in the state where the lens barrel is mounted on the camera body, the lock operation is controlled after the release is completed or after a predetermined time has elapsed after the finger is released from the release button after focusing.

When the release button of the camera is half pressed, the lock of the correction lens is released in synchronization with the focusing operation to perform the shake correction. Further, when the focus is manually adjusted, the position of the focus ring 20 is detected, and when it is recognized that it is within the photographing range, the shake correction is started (not shown).

According to the present embodiment, as shown in FIG.
The second group lens barrel 19 for holding the second group lens L2 is provided with a projection 19c, and the pressing plate 21 integral with the focus ring 20 is provided with an inner peripheral convex portion 21a at a portion corresponding to a super-infinite position. When the lens L2 is locked at a predetermined position, the focus ring 20 is driven to an ultra-infinite position by using the focus driving ultrasonic motor 13.

Therefore, as in the conventional example shown in Japanese Patent Laid-Open No. 5-100280, a mechanism and an actuator dedicated to locking are required, and the entire lens barrel is increased in size and cost due to the locking device and consumed. The problem of increased power consumption can be eliminated.

At the same time, unlike the conventional example shown in Japanese Patent Laid-Open No. 5-100280, it is possible to eliminate the problem that a locking pin and a coil spring are required and the locking mechanism is complicated.

(Correspondence between Invention and Embodiment) In the present embodiment, the focus ring 20 and the pressing plate 21 correspond to the focus driving member of the present invention, and the inner peripheral convex portion 21a is provided on the focus driving member. The projection 19
c corresponds to the locking means of the present invention.

The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention, but the present invention is not limited to the configurations of these embodiments, and the functions shown in the claims,
It goes without saying that any structure may be used as long as the functions of the embodiments can be achieved.

(Modification) The present invention has been shown as an example applied to an interchangeable lens for a single lens reflex camera, but the present invention is not limited to this and may be applied to a video camera or a lens shutter camera. Particularly, in the lens shutter camera, it is sufficient to operate only during the release of both focus and shake correction, and the effect of the present invention is great.

[0051]

As described above, according to the present invention,
The focus driving member is provided with an engaging portion for disabling movement of the correction lens for image blur correction, and the focus driving member engages with the engaging portion when the focus driving member moves beyond the photographic range, and the correction lens Locking means is provided for locking the in position.

Therefore, a member such as an actuator for driving the locking means for locking the correction lens can be eliminated, and the lens barrel or the camera can be made compact and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a zoom lens barrel according to an embodiment of the present invention.

FIG. 2 is a development view of a cam barrel and a fixed barrel of FIG.

3 is a cross-sectional view showing details of a correction unit and a focus adjustment structure in FIG.

FIG. 4 is a plan view of a holding plate and a second group lens barrel attached to the back surface of the focus ring of FIG. 1 as viewed from the mount side.

[Explanation of symbols]

1 fixed tube 4 cam barrel 4b Focus cam 19 Second group lens barrel 19c protrusion 20 focus ring 21 Presser plate 21a Inner peripheral convex portion 50 Shake correction unit 55 cyst frame Second lens group that composes L2 correction lens

Claims (3)

(57) [Claims] 1. A correction lens that moves in a direction other than the optical axis of a photographing optical system to perform image blur correction, and a focus drive member, and when the focus drive member is driven to perform focus adjustment, In the lens barrel configured to move the correction lens in the optical axis direction, the focus driving member has an engaging portion that disables movement of the correction lens for image blur correction, A lens barrel comprising: locking means that engages with the engaging portion when the member moves beyond a photographable range and locks the correction lens at a predetermined position. 2. The lens barrel according to claim 1, wherein the locking means is provided integrally with a correction lens frame that holds the correction lens. 3. A camera comprising the lens barrel according to claim 1 integrally.