JP2002107602A - Lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens barrel capable of correcting image blurring and also capable of coping with the miniaturization of a lens barrel such as a collapsible barrel type. SOLUTION: An image blurring correcting device 5 with an image blurring correction lens L2 is integrally formed with a shutter unit 6. By fitting a cam pin 11 arranged in the shutter unit 6 into a cam groove 13 formed in a rotary barrel 2 and a straight advance groove 9 formed in a fixed frame 8 and then rotating the rotary barrel 2, the image blurring correcting device 5 is moved in an optical axis direction in accordance with a zooming magnification. By moving the image blurring correcting device 5 in the optical axis direction in such a way, the miniaturization is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel for correcting camera shake, and more particularly, to miniaturization of the lens barrel.

[0002]

2. Description of the Related Art In recent years, consumer video cameras have been reduced in size and weight, and optical zooms have been increased in magnification. For this reason, a video camera is an ordinary video device for ordinary photographers. However, on the other hand, the miniaturization, weight reduction, and high magnification of the optical zoom have caused video camera users who are not proficient in shooting, if the camera shake occurs during shooting, the screen becomes unstable. . Therefore, in order to reduce such troubles, many video cameras equipped with a camera shake correction device have been developed and already commercialized.

As a camera shake correcting device for this video camera, Japanese Patent Application Laid-Open No. 2000-75335 filed by the present inventor has been proposed.
As described in Japanese Patent Application Laid-Open Publication No. H11-264, a method has been proposed in which a correction lens group is moved in two directions perpendicular to the optical axis to correct camera shake by a photographer and obtain a stable image.

[0004]

However, the above-mentioned conventional lens barrel has the following problems.

[0005] That is, with the rapid spread of digital still cameras in recent years, the opportunity to take a still image at a high resolution and print the taken image greatly enlarged has increased. In the case of a digital still camera, the optical magnification is 3
In particular, in photographing in a situation in which the strobe cannot be fired, camera shake occurs even at about three times, and the inconvenience that the printed image becomes difficult to see due to the influence of camera shake occurs. In order to improve portability when not in use, the digital still camera is generally equipped with a retractable lens barrel that can be stored. However, the conventional image blur correction device mounted on a video camera or the like does not have a configuration corresponding to the retractable type.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens barrel which can cope with miniaturization such as a collapsible type while performing image blur correction.

[0007]

According to a first aspect of the present invention, there is provided a lens barrel including a lens movable along an optical axis together with an image blur correction lens for correcting an image blur; An image blur correction unit equipped with the image blur correction lens, a driving unit for moving the lens and the image blur correction unit in the optical axis direction, and moving in the optical axis direction integrally with the image blur correction unit to reduce an exposure amount. And a shutter means for controlling.

[0008] With this configuration, a lens barrel in which the lens and the image blur correcting means can be moved in the optical axis direction by the driving means can be realized, and it is possible to cope with a retractable camera or the like.

According to a second aspect of the present invention, in the lens barrel according to the first aspect, the driving means changes the zoom magnification by moving the lens and the image blur correction lens in the optical axis direction. .

[0010] The third aspect of the present invention is the first or second aspect.
3. The lens barrel according to claim 1, further comprising a first flexible print cable provided in the image blur correction means, and a second flexible print cable provided in the shutter means, wherein the first and second flexible print cables are movable. It is characterized in that the parts are integrated.

With this configuration, the flexible printed cable can be routed inside the lens barrel without any trouble.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First, a lens barrel according to a first embodiment of the present invention and a camera having the lens barrel will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a lens barrel according to a first embodiment, FIG. 2 is a perspective view showing an image blur correction device and a shutter unit of the lens barrel, and FIGS. 3A and 3B are the same. FIG. 4 is a sectional view of a main part showing a collapsed state and a photographing state of the lens barrel, respectively, FIG. 4 is a block diagram showing a hardware configuration of a camera having the lens barrel, and FIGS. It is a perspective view which shows a collapsed state and a photography state, respectively.

The lens barrel 1 is of a retractable type, and is an optical system that changes the focal length by moving the first lens group L1 and the second lens group (image blur correction lens) L2 back and forth in the optical axis direction by the cam barrel 2. is there. The CCD 3 is disposed at the image forming position of the zoom lens while being attached to the back plate 7. These first group lens L1 and second group lens L2 are held by the first group lens frame 4 and the image blur correction device 5, respectively. Further, the image blur correction device 5
Are integrally held by a shutter unit 6 that controls the exposure time of the CCD 3. This shutter unit 6
Has an aperture blade or shutter blade 6a having a fixed aperture diameter, and a drive motor (built-in to the shutter unit 6 and not shown) for driving the blade.

The first group lenses L1 and L2 are fixed at predetermined positions.
A plurality of rectilinear grooves 9 are formed on the outer periphery of the fixed cylinder 8 for guiding the group lens L2 along the direction of the optical axis A. The cam pins projecting from the first group lens frame 4 in the rectilinear grooves 9 1
0 and a cam pin 11 protruding from the shutter unit 6 are fitted respectively. Cam pins 10, 11
Are projected at equal intervals (120 ° intervals) on the outer peripheral portion of the first lens group frame 4 and the shutter unit 6, and three rectilinear grooves 9 are also formed at equal intervals. Thereby, the first lens group frame 4 and the shutter unit 6
Since it is stably supported in the rectilinear groove 9 via the three cam pins 10 and 11, it can move back and forth in the direction of the optical axis A. Further, the cam pins 10 and 11 penetrate through the rectilinear grooves 9 and are fitted into cam grooves 12 and 13 formed on the inner periphery of the cam cylinder 2. The cam grooves 12 and 13 are formed in a non-linear shape determined according to the movement trajectory of the first lens group frame 4 and the shutter unit 6.

The cam barrel 2 is rotatably provided on the outer periphery of the fixed barrel 8. A gear 14 is provided on the outer periphery of the cam cylinder 2.
The driving force transmission gear 15 is meshed with the gear 14. The driving force transmission gear 15 is connected to an output shaft of a cam cylinder driving motor 17 (hereinafter abbreviated as a driving motor) via a reduction gear train 16. Therefore, when the driving motor 17 is driven, the driving force is transmitted from the reduction gear train 16 to the driving force transmission gear 15 and the cam cylinder 2 is driven.
Is rotated. As a result, the first group lens frame 4 and the shutter unit 6 are guided by the
Since it moves along the shapes 2 and 13, zooming is performed.

The focus adjustment lens unit L 3 is held by a third lens unit frame 18. This third group lens frame 18
Is supported by two guide poles (not shown) arranged in parallel with the optical axis A, and is linearly moved in the front-rear direction along the optical axis A by a motor (not shown).

Next, the image blur correction device 5 will be described with reference to FIG. In the image blur correction device 5, the second lens unit L2 that corrects image blur during photographing is fixed to a holding frame 20 that is movable in the Y direction shown in FIG. Hereinafter, the holding frame 20 is referred to as a pitching movement frame. The pitching movement frame 20 is provided with a bearing 20a for receiving the pitching shaft 21a disposed along the Y direction and a rotation stopper 20b engaged with the pitching shaft 21b disposed along the Y direction. , And can slide along the Y direction via these two pitching shafts 21a and 21b.

On the lower side of the pitching moving frame 20,
An electromagnetic actuator 22y is arranged. The electromagnetic actuator 22y includes a coil 23y attached to the pitching movement frame 20, a magnet 24y attached to the shutter unit 6, and a yoke 25y. The magnet 24y is two-pole magnetized on one side, and is fixed to a U-shaped yoke 25y that is open on one side.

Further, on the right side of the pitching movement frame 20, an electromagnetic actuator 22x is arranged. The electromagnetic actuator 22x includes a coil 23x attached to the pitching movement frame 20 and a shutter unit 6
24x and yoke 25x to be attached to
It is composed of Magnet 24x is 2 on one side
Polarized, U-shaped yoke 25x open on one side
It is fixed to.

A frame 26 for moving the lens unit L2 for correcting image blur in the X direction is mounted in the -Z direction of the pitching movement frame 20. Hereinafter, the frame 26 is referred to as a yawing movement frame. In the Z direction of the yawing movement frame 26, two pitching shafts 21a and 21b for sliding the pitching movement frame 20 described above in the Y direction.
Fixing portions 27c and 27d (two locations) are provided for fixing both ends of the optical disk. In the yawing movement frame 26, X
A bearing 28a for receiving the yawing shaft 29a arranged along the direction and a detent 28b engaged with the yawing shaft 21b arranged along the X direction are provided, and these two yaw shafts 29a are provided. , 29
It is configured to be slidable along the X-direction via b. The yawing shaft 29a is connected to the yawing moving frame 2
6 is fixed to two fixing portions 6c of the shutter unit 6 provided in the -Z direction. Further, the yawing shaft 29b is slidable by a rotation stopper 6d provided on the shutter unit 6. Therefore, when a current flows through the coil 23y of the pitching movement frame 20, an electromagnetic force is generated in the Y-axis direction by the magnet 24y and the yoke 25y. Similarly, when a current is applied to the coil 23x of the pitching movement frame 20, an electromagnetic force is generated in the X-axis direction by the magnet 24x and the yoke 25x. As described above, the two-unit lens L2 for correcting image blur is driven by the two electromagnetic actuators 22y and 22x in two directions X and Y substantially perpendicular to the optical axis Z direction.

Next, the position detecting means 30 for detecting the position of the second lens group L2 for correcting image blur will be described. The position detecting means 30 of the pitching movement frame 20 equipped with the second group lens L2 includes a light emitting element 31 (hereinafter, referred to as an LED),
A slit 32 formed in the pitching movement frame 20 and a light receiving element 33 (hereinafter, referred to as a light receiving element) fixed to the shutter unit 6.
2D PSD). The position detecting means 30 detects the position of the pitching movement frame 20 on the X, Y axis plane by using a set of LEDs 31 and a two-dimensional PSD 33. The LED 31 emits light through a slit 32 having a substantially circular shape. The projection light that has passed through the slit 32 from the LED 31 is incident on the two-dimensional PSD 33, and converts the spot light of the LED 31 into a photocurrent output corresponding to the incident position. Then, by calculating the photocurrent output, the second group lens L for image blur correction is calculated.
2 two-dimensional position coordinates can be obtained.

Next, the hardware configuration of the camera 35 (see FIG. 5) equipped with the retractable lens barrel 1 will be described with reference to FIG. The camera 35 is equipped with a microcomputer 34 as control means for controlling the camera 35. This microcomputer 34 includes a camera 35
The drive motor 17 is controlled via a motor control means 38 on the basis of signals from a power button 36 and a zoom lever 37 provided in the camera. The drive motor 17 rotates a predetermined amount according to a command from the motor drive control means 38.
The lens barrel 1 is driven by the driving force. The microcomputer 34 determines the current zoom position of the lens barrel 1 by counting, for example, the number of pulses output from the motor drive control means 38. By operating the zoom lever 37, the lens barrel 1 is moved to a predetermined zoom position. Also,
By pressing the shutter button 39, the shutter drive control means 40 controls the drive motor of the shutter unit 6. Therefore, by opening and closing the shutter blades 6a of the shutter unit 6, the exposure time of the CCD 3 can be controlled, and an image can be taken at an arbitrary zoom magnification.

The CCD 3 is an image pickup device for converting an image incident through the image pickup optical system into an electric signal, and its operation is controlled by the CCD drive control means 42. Analog signal processing means 43 is connected to the CCD 3, and the analog signal processing means 43 performs analog signal processing such as gamma processing on the video signal obtained by the CCD 3. An A / D converter 44 is connected to the analog signal processor 43, and the A / D converter 44 converts the analog video signal output from the analog signal processor 43 into a digital signal. A digital signal processing means 45 is connected to the A / D conversion means 44.
Performs digital signal processing, such as noise removal and contour enhancement, on the video signal converted to a digital signal by the A / D converter 44.

The camera 35 is provided with an angular velocity sensor 46 for detecting the movement of the camera 35 including the lens barrel 1 itself. The angular velocity sensor 46 outputs both positive and negative angular velocity signals according to the direction of movement of the camera 35 based on the output when the camera 35 is stationary. The angular velocity sensor 46 includes two sensors that detect movement in two directions, yawing and pitching. FIG. 4 shows only one-directional sensor. As described above, the angular velocity sensor 46 has a function of a motion detecting unit that detects the motion of the camera 35 due to camera shake and other vibrations. The angular velocity sensor 46 includes an angular velocity sensor 46
An HPF 47 which is a high-pass filter for removing a DC drift component in an unnecessary band component included in the output of the sensor is connected to the HPF 47. LP, which is a low-pass filter that removes noise components and noise components
F48 is connected. After the output from the LPF 48 is input to the amplifier 49 which is a circuit for adjusting the output signal level of the angular velocity sensor 46, the amplifier 4
9 via an A / D converter 50 which is a converter for converting the output signal of the microcomputer 9 into a digital signal.
4 given. The microcomputer 34 has an A / D
The output signal of the angular velocity sensor 46 fetched via the conversion means 50 is subjected to filtering, integration processing, phase compensation,
It performs gain adjustment, clip processing, and the like, obtains a drive control amount of the second lens unit L2 necessary for motion correction, and outputs the amount to the correction lens unit drive control unit 41.

The correction lens group drive control means 41 is a control means for driving and controlling the second lens group L2 for image blur correction, and includes an image pickup optical system (first lens group L1, second lens group L1).
2. The second lens unit L2 is moved up, down, left and right within a plane orthogonal to the optical axis A of the focus adjustment lens unit L3).
The position detecting means 30 detects the actual amount of movement of the second group lens L2, and the position detecting means 30 forms a feedback control loop for driving and controlling the second group lens L2 together with the correction lens group driving control means 41. ing. Such 2
The group lens L2 and the correction lens group drive control means 41 form a motion correction means for controlling the optical axis A of the imaging light.

The operation of the lens barrel 1 configured as described above will be described below. When the power button 36 of the camera 35 is pressed, the power of the camera 35 is turned on, and the driving motor 17 of the lens barrel 1 is rotated. Then, by rotating the cam barrel 2, the first lens unit L1 is moved from the collapsed state to the photographing state.
And the second lens unit L2 is moved. A sectional view of the lens barrel 1 at that time is shown in FIG. The rotation of the cylindrical cam 2 causes the first group lens frame 4 and the shutter unit 6
The image blur correction device 5 integrated with the camera 1 goes straight to the left in FIG. By rotating the cam barrel 2 in the range from Wide to Tele, the first-group lens frame 4 and the image blur correction device 5 integrated with the shutter unit 6 are moved along the cam grooves 12 and 13. Optical axis A
Since it moves back and forth in the direction, zooming can be performed. The focus adjustment is performed by driving a motor (not shown) to move the third lens group frame 18 in the optical axis A direction. Conversely, when the power of the camera 35 is turned off, the cam barrel 2 is rotated from the imaging state to the collapsed state. FIG. 3B is a sectional view of the lens barrel 1 at that time. Image blur correction device 5 integrated with first lens group frame 4 and shutter unit 6 by rotation of cylindrical cam 2
Travels rightward in FIG. 3B. as a result,
The length of the lens barrel 1 in the direction of the optical axis A is L, which can be shortened as compared with the time of shooting.

Next, the operation of the image blur correction device 5 will be described. The camera shake acting on the camera 35 equipped with the image blur correction device 5 is detected by two angular velocity sensors 46 arranged at an angle difference of 90 degrees from each other. Angular velocity sensor 4
6 is converted into a blur angle of a camera 35, and the microcomputer 34 converts the output into a second lens group L.
2 of the target position information. In order to move the second lens group L2 according to the target position information, the correction lens group drive control means 41 calculates a difference between the target position information and the current position information of the second lens group L2, and
The signal is transmitted to 2y and 22x. Electromagnetic actuator 2
2y and 22x drive the second lens unit L2 based on this signal. The operation of the second lens unit L2 is determined by the position detection unit 30.
, The image blur generated in the camera 35 can be corrected.

At this time, the camera 3 equipped with the lens barrel 1
5 is in the collapsed state shown in FIG. 5A when not in use,
The retractable lens barrel 1 is a camera 35 excellent in morphology without protrusions. In addition, at the time of photographing, the state shown in FIG. 5B is obtained, and the photographing can be performed at an arbitrary zoom magnification by extending the lens barrel 1.

As described above, according to the present embodiment, the image blur correction device 5 for correcting the camera shake of the photographer can be moved in the direction of the optical axis A in accordance with the zoom magnification. The degree of freedom in optical design is increased as compared with the case where the lens is fixed in the optical axis direction. Furthermore, since the camera 35 can be retracted when not in use, the camera 35 having excellent portability can be provided. Further, by integrating the image blur correction device 5 with the shutter unit 6 which is a conventional component, a moving frame that moves in the direction of the optical axis A and a cam that regulates the movement of the moving frame in the direction of the optical axis A Since there is no need to increase the number of grooves, the configuration is simple,
The collapsible lens barrel 1 with a small number of parts can be realized.

In the above embodiment, the collapsible lens barrel 1 capable of storing the lens barrel when not in use has been described. However, the entire optical length when photographing and when not in use is the same. Even if the image blur correction device moves in the direction of the optical axis in accordance with the zoom magnification, it is possible to realize a lens barrel that is smaller than ever before.

The movement of the image blur correction device 5 integrated with the shutter unit 6 in the direction of the optical axis A is performed by using the cylindrical cam 2. However, the present invention is not limited to this method. The same effect can be obtained even in a configuration in which the movement is performed by utilizing the above.

The structure of the image blur correction device 5 is not limited.
May be a magnetic type instead of an optical type. Further, in the above-described embodiment, the case where the present invention is applied to a digital still camera provided with the CCD 3 has been described. However, similar effects can be obtained by using the lens barrel for a conventional silver halide film.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a perspective view showing an image blur correction device and a shutter unit according to the second embodiment, and FIG. 7 is a sectional view of a lens barrel showing a state of a movable portion of a flexible print cable. The components described so far are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 6 and FIG.
Are provided with flexible print cables 50 to 53 for connecting the shutter unit 6 and the image blur correction device 5 of the lens barrel 1 with a circuit on the camera body side (a circuit located outside the lens barrel 1). Have been.

One end of the flexible print cable 50 is connected to the coil 23y of the pitching actuator 22y of the image blur correction device 5 and the yaw actuator 2
2x coil 23x and LED of position detecting means 30
31. Further, the other end of the flexible print cable 50 is connected to an external drive control circuit mounted on the camera 35, that is, the correction lens group drive control means 41 in the present embodiment. One end of the flexible print cable 51 is connected to the two-dimensional PSD 33, and the other end is connected to the correction lens group drive control unit 41. One end of the flexible print cable 52 is connected to the motor drive unit 6 built in the shutter unit 6.
b and the other end is shutter drive control means 40
Connected to.

These flexible printed cables 5
0, 51, and 52 need to be arranged inside the lens barrel 1 in order to connect to an external circuit. Further, the image blur correction device 5 integrated with the shutter unit 6 needs to have a certain amount of flexure by moving in the direction of the optical axis A according to the zoom magnification. In order to solve this problem, three flexible printed cables 50, 51,
The non-fixed side (referred to as a movable portion) of the lens 52 is assembled as a single flexible print cable 53 and pulled out of the collapsible lens barrel 1.
This state is schematically shown in FIG.

The operation of the thus constructed lens barrel 1 will be described. The image blur correction device 5 is connected to the electromagnetic actuators 22y and 22y via the flexible print cable 50.
2x is driven in two directions orthogonal to the optical axis A by supplying power. Also, by supplying power to the LED 31 via the flexible print cable 50 and obtaining output from the secondary PSD 33 via the flexible print cable 51, the position of the image blur correction device 5 can be detected. Further, by supplying electric power to the motor drive unit of the shutter unit 6 via the flexible print cable 52, it becomes possible to control the amount of exposure to the CCD 3.

The movable parts of the flexible printed cables 50 to 52 for connecting the shutter unit 6 and the image blur correcting device 5 to an external circuit are integrally formed as one flexible printed cable 53. The complicated arrangement of the flexible printed cables 50 to 53 in the collapsible lens barrel 1 can be eliminated, a small space can be effectively used, and the flexible collapsible lens barrel 1 can be pulled out of the collapsible lens barrel 1. Becomes

[0039]

As described above, according to the present invention, since the image blur correction device equipped with the image blur correction lens can be moved along the optical axis direction, the degree of freedom in optical design can be increased more than ever. It is possible to realize a lens barrel corresponding to an increase in size, miniaturization, and further increase in pixels. Further, when the camera is not used, the camera can be retracted, and a camera excellent in portability can be provided. In addition, since the image blur correction device is integrated with the shutter unit, there is no need to increase the number of moving grooves that move in the optical axis direction and the number of cam grooves that regulate the movement of the moving frames in the optical axis direction. And a remarkable effect that a lens barrel with a small number of parts can be realized is obtained.

Further, since the flexible printed cable for connecting the shutter unit and the image blur correction device to an external circuit is integrated in the movable portion in the lens barrel, the flexible printed cable in the lens barrel is complicated. A remarkable effect is obtained that the troublesome arrangement can be eliminated and the space can be effectively used to draw out the lens barrel.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lens barrel according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an image blur correction device and a shutter unit of the lens barrel.

FIGS. 3 (a) and 3 (b) are cross-sectional views of relevant parts showing a collapsed state and a photographing state of the lens barrel, respectively.

FIG. 4 is a block diagram showing a hardware configuration of a camera having the lens barrel.

FIGS. 5A and 5B are perspective views respectively showing a collapsed state and a photographing state of the camera.

FIG. 6 is a perspective view illustrating an image blur correction device and a shutter unit according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a lens barrel showing a state of a movable portion of the flexible print cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens barrel 2 Rotating cylinder 3 CCD 4 1 group lens frame 5 Image blur correction device 6 Shutter unit 12, 13 Cam groove 17 Drive motor 22 Image blur correction actuator 35 Camera 36 Microcomputer 38 Motor drive control means 40 Shutter drive control Means 41 Correction lens group drive control means 50 to 53 Flexible print cable L1 First group lens L2 Second group lens (image blur correction lens) L3 Third group lens

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 17/02 G03B 17/04 17/04 G02B 7/04 DE F term (Reference) 2H044 AE06 BD07 BD10 BE17 EC07 EE01 2H100 AA31 AA33 BB06 BB08 BB11 EE01 2H101 BB07 BB08 DD21 DD41 DD62 DD65

Claims (3)

[Claims] 1. A lens movable along the optical axis together with an image blur correction lens for correcting image blur, an image blur correction unit equipped with the image blur correction lens, and an optical axis. A lens barrel comprising: a driving unit that moves in the direction of the image; and a shutter unit that moves in the optical axis direction integrally with the image blur correction unit and controls an exposure amount. 2. The lens barrel according to claim 1, wherein the driving unit changes the zoom magnification by moving the lens and the image blur correction lens in the optical axis direction. 3. A first flexible printed cable provided in the image blur correcting means, and a second flexible printed cable provided in the shutter means.
And a flexible printed cable of the first,
3. The lens barrel according to claim 1, wherein the movable portion side of the second flexible printed cable is integrated.