JPH03188430A - Image blurring restraining device for camera - Google Patents

Abstract

PURPOSE:To prevent the divergence of focus at the time of restraining image blurring by constituting a correction optical mechanism which makes an optical axis eccentric so that it does not give movement component in an axial direction to a correction lens and floatably supporting it. CONSTITUTION:A lens holding frame 13 is floatably supported in a pitch direction with respect to a 1st holding frame 16, and floatably supported in a yaw direction with respect to a 2nd holding frame 119. Then, a slit 123 is provided on a yaw coil 18 and a projector such as an infrared light emitting diode, etc., and a light receiving device such as a semiconductor detection element, etc., which are fixed to the 2nd holding frame 119 at positions on both sides which put the slit 123 between them are combined to detect the position of the 1st holding frame 16 in the yaw direction with respect to the 2nd holding frame 119. Namely, the lens holding frame 13 (consequently, the correction lens 12) is floatably supported in the pitch direction 11p and the yaw direction 11y on a plane orthogonally crossed with the optical axis O. Thus, the movement of the lens in the optical axis direction is not caused, so that the divergence of focus is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device used to suppress vibrations of equipment that is subject to relatively low frequency vibrations, for example, about IHz to 12) 1z that occurs in equipment such as cameras. This invention relates to a system that detects vibrations (camera shake) at a frequency of , and uses this as image blur suppression information to prevent image blur.

[Prior Art] The conventional technology to which the present invention is applied will be described below, taking the case of a camera as an example.

Modern cameras automate all the necessary steps for shooting, such as determining exposure and focusing, so even those who are inexperienced in camera operation are less likely to make a shooting mistake. Failures were thought to be difficult to prevent with automatic fishing. Recently, there has been active research into cameras that can prevent photographing failures caused by camera shake, and in particular, cameras that are designed to prevent photographic failures due to camera shake are being developed and researched.

Camera shake during shooting is usually a vibration with a frequency of IHz to 121 (Z), but even if such camera shake occurs at the time of camera shutter release, it is possible to take a picture without image blur. As a basic idea, it is necessary to detect camera vibration caused by camera shake and to displace the correction lens according to the detected value. (Be able to take photos without image blur)
In order to achieve this, it is first necessary to accurately detect camera vibrations and correct optical axis changes caused by camera shake.

In principle, detection of this vibration (camera shake) requires a vibration sensor that detects angular acceleration, angular velocity, etc., and a camera shake detection system that electrically or mechanically integrates the sensor signal and outputs angular displacement. This can be done by installing it on the camera. Based on this detection information, image blur is suppressed by driving a correction optical mechanism that decenters the photographing optical axis. Here, an outline of an example of a conventional image blur suppression system using an angular velocity meter as a vibration detection sensor will be explained with reference to FIG. This example is shown in 41
Vertical camera shake 41p and horizontal camera shake 41 in the direction of the arrow
This is to suppress image blur caused by y. 42 in the same figure
is a lens barrel, 43p and 43y are angular velocity meters for detecting the vertical shake angular velocity of the camera and the horizontal shake angular velocity of the camera, respectively, and 44p and 44y indicate the detection directions of the respective angular velocities. 45p and 45y are integrators constructed using a known analog integration circuit, which integrate the signal from the gyrometer and convert it into camera shake angular displacement. Then, the signal drives the correction optical mechanism 46 (47p and 47y are drive units thereof, and 489 and 48y are position detection sensors for the correction lens) to ensure stability on the image plane 49. In addition,
It is also possible to provide the correction optical mechanism itself with a mechanical integration function and omit the analog integration circuit described above.

FIG. 2 is a diagram for specifically explaining a conventional configuration example of the correction optical mechanism 46 mentioned above. In this figure, a correction lens barrel 4 with a correction lens 23 assembled at its tip.
6° is the detection shake direction 41 described above by the gimbal 21.
It is supported so as to be rotatable around two orthogonal axes 22L and 22V that coincide with p and 41y. That is, the gimbal 21 is supported so as to be rotatable around an axis 22F with respect to the lens barrel 42 (not shown in FIG. 2), which is a fixed part, and furthermore, the correction lens barrel 46° can be rotated around an axis 22p. I support it.

At the rear end of the correction lens barrel 46, yokes 25p and 25y and permanent magnets 269.2 are arranged opposite to the voice coils 24p and 24y provided on the lens barrel 42, which is a fixed part.
6y is provided, and the voice coil is 24p.

By energizing and excitation of 24y, a magnetic driving force according to Fleming's law is generated.

Therefore, by controlling the energization and excitation of the voice coils 24p and 24y in accordance with the amount of correction for suppressing image blur, the desired suppression of image blur on the image plane 49 can be achieved.

Symbols 29p, 29y to 212p in FIG. 2(a),
Reference numeral 212y indicates an electrical control circuit for controlling the energization and excitation of the voice coils 24p and 24y, for example, the magnetoresistive sensor 27p provided on the cymbal 21.
, 27y, and a magnetic marker 28ρ, zay (however, 28y
(not shown in the drawing), the correction lens barrel is 46°.
The declination angles around the respective axes 22p and 22y are extracted as electrical signals, and these signals are input to the position detection amplifier circuit 29L29V. The amplified signal is further passed through a compensation circuit 210p for stabilizing characteristics.

210y, differential amplifier 211p, 211y, drive circuit 2
12p.

212y and the voice coil 24p.

24y is excited. and the differential amplifier 211p,
Signals from the integrating circuits 4sp and 4sy of the camera shake detection system (vibration detection system) described above are input to 21131.

With the above configuration, the control circuit has integral circuits 45p, 4
If there is no human power from 5y, the position of the correction lens barrel 46° is controlled so that it is parallel to the photographing optical axis at a predetermined neutral position.On the other hand, if the camera shakes, the integrating circuit 45
By human power from p and 45y, the correction lens barrel 46'
is oscillated to decenter the photographing optical axis so as to suppress image blur on the image plane 49.

The correction lens barrel 46° of the correction optical mechanism is provided so that the weight of the correction lens 23 at the tip and the yokes 2Fl, 25y, etc. at the rear end is balanced with the gimbal 21 in between. This causes the axes 22p, 22y to substantially pass through their center of gravity, thereby causing these axes 22p, 22y to pass substantially through their center of gravity.
, zzy, the parallelism with the photographing optical axis is maintained without requiring the force of the voice coils 24p and 24y unless rotational disturbance (shaking) about , zzy occurs.

[Problems to be Solved by the Invention] However, in the configuration of the conventional example described above, when the correction lens barrel is driven 46 degrees and tilts from the photographing optical axis, as shown in FIG. 2(b), the target optical axis In addition to eccentricity, the following disadvantages occur. One of them is that the correction lens 2
3 rotates according to a rotation locus centered on the cymbal 21, causing a maximum displacement of δ1 in the optical axis direction at the peripheral edge of the lens. For this reason, the photograph taken becomes an unsightly photograph in which the focus becomes weaker toward the periphery.

In order to solve this problem, a parallel link type correction optical mechanism shown in FIG. 3(a) has also been proposed.

This parallel link type correction optical mechanism will be explained with reference to FIG.
Two mutually perpendicular directions 33p, 3 perpendicular to the optical axis 32
It has a structure that allows it to move using parallel links on the 3y. That is, in FIG. 3(a), the ball bearing 35p+, 351)2.
3sy1.35y2 (35pt.

35y2 are supported by 36
A bracket 37p rotatable in the p and 36y directions.

37p2, 377, 37y2 are provided, and ball bearings 38p, 38p are installed from above each of these brackets.
2゜3B>'+, 38V2 Beams 39pl, 39p2.39y1.39Y2 are supported by (38pl is not shown in the drawing) and are rotatable in the 36y and 36p directions, respectively.
(3992, 3Dt is only partially visible in the drawing) is extended.

As a result, each of the six beams is connected to the bracket 37 relative to the holding frame 34.
1) 3 centered on 1.3792.37y1.37y2
6p.

It can be rotated in both directions at 36V.

FIG. 3(b) is an enlarged view of a part of the beam 39y2,
A flexible spring wire 310 is attached to the tip of the beam in a direction perpendicular to the optical axis 32, and the lens frame 31 is supported by this spring wire 310. Therefore, the beam is 39p+, 39G12 (also 39y1.39y
2) has a parallel link structure centering on the bracket and can shift the lens frame 31 in parallel in the 33p (or 33y) direction.

Then, a position sensor 311 using magnetoresistive effect etc. is attached to the bracket 37y2, and the beam 39y
A configuration is provided to detect the amount of rotation of the beam 39y2 around 36p in relation to the magnetic body 312 embedded in the bracket 37p2, and a position sensor is similarly attached to the bracket 37p2.
It is provided to detect the amount of rotation around 36M. Furthermore, the beams 39pz and 39V* are equipped with voice coils 313p and 313y as driving sources, as shown in FIG. 3(a).
Attach. FIG. 3(c) is an enlarged view of the voice coil 313p attached to the beam 39y2, and shows the yoke 31 fixed to a fixed part (not shown) (part of the lens barrel 42).
4p (3151),.

3151) 2 is a permanent magnet) A magnetic circuit is formed as shown by a broken line 316 in the figure. In this state, the voice coil 31
By passing a current through the coil 39 (wound in the direction of arrow 317y), a driving force is generated in the direction of arrow 318p, and the lens frame 31 is shifted in the direction of arrow 33p. Voice coil 313y attached to beam 39p2
is similarly configured, and when energized, the lens frame 31 is moved in the direction of the arrow 33.
It can be shifted in the y direction.

The correction optical mechanism having such a configuration has the advantage that the out-of-focus at the peripheral edge of the lens described in FIG. 2(b) does not occur.

However, in this mechanism, as shown in Figure 3(d), due to the parallel link structure, it is inevitable that the correction lens will shift by δ in the optical axis direction when the optical axis is decentered, and as a result, the overall focus will be It shifts slightly. In cameras that employ recent automatic focusing mechanisms, it is possible to correct this problem of focus deviation by driving the automatic focusing mechanism. However, with this method of tracking using the automatic focusing mechanism, the lens of the automatic focusing mechanism is extended when suppressing image shake, which makes an unpleasant sound. Also, camera shake is caused by a fairly high frequency ( 308
Z) is also included, but it is difficult to correct this high-frequency defocusing using the automatic focusing mechanism due to the responsiveness of the mechanism.

Therefore, the correction optical mechanism of the above-mentioned mechanism has a problem in that it must accept a certain degree of out-of-focus.

Furthermore, as another drawback, Fig. 2(a) and Fig. 3(a)
Regarding the correction optical mechanisms shown in , since both have a rotation center, each length f, , fi2 from the rotation center.
The correction lens is held at a position of 1. , fL
If , is shortened, a slight eccentricity of the optical axis will cause a large out-of-focus.

Therefore, it is not preferable to shorten the lengths JLI and IL2, and there is a problem in that the correction optical mechanism becomes larger as a result. This is a major mechanical drawback at a time when cameras are required to be more compact.

The present invention has been developed in view of the problems of the conventional mechanism as described above.
It is an object of the present invention to provide an image blur suppressing device with a novel configuration that does not cause out-of-focus due to image blur suppression.

[Means for Solving the Problems and Effects] The feature of the camera image blur suppressing device according to the present invention that achieves the above object is that it suppresses image blur on the image plane based on detection information of vibrations generated in the lens barrel. An image blur suppression device for a camera that determines the necessary amount of correction for optical axis eccentricity and controls the movement of a correction optical system, which is floatingly supported so as to be movable in the radial direction relative to the lens barrel, according to the amount of correction. The floating support of the correction optical system is a first support that supports the correction optical system so as to be movable in a first direction defined in a plane perpendicular to the optical axis, but restrains movement in other directions. a holding frame;
a second direction in a second direction different from the first direction within the plane;
and a second holding frame which movably supports the holding frame of but restricts movement in other directions, and this '! The holding frame of J2 is fixed to the lens barrel.

With the above configuration, it is possible to avoid misalignment of the correction optical system in the optical axis direction during image blur suppression control.

Note that the mechanical component including the correction optical system may be provided so as to be movable in the optical axis direction as necessary for operations such as focusing and zooming.

[Example] The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a diagram for explaining the correction optical mechanism of the image blur suppressing device according to the present invention, and other configurations of the device are shown in the fourth embodiment.
Since it can be constructed as the same as the conventional example shown in the figure, illustration and description thereof will be omitted.

In FIG. 1, 12 is a correction lens, 13 is an annular lens holding frame to which this correction lens 12 is fixed,
In this example, boss portions 13a for bearings are provided on both sides in the horizontal direction (horizontal direction in FIG. 1(a)).

13a is formed to extend, and this boss portion 13a.

A pitch shaft 15 fixed to a first holding frame 16 (described later) is supported so as to be slidable in the vertical direction via a bushing 14 made of oil-free metal fitted into a hole passing through the shaft 13a in the vertical direction in the figure. As a result, the lens holding frame 13 is vertically movably supported by the first holding frame 16 via left and right sliding bearings.

Furthermore, pitch coil springs 17.1 are attached to the pitch shafts 15 between the mounting portions (there are two locations above and below) and the boss portions 13a of the lens holding frame 13 to the first holding frame 16.
7 are sheathed, and these pitch coil springs 17.
, 17, the lens holding frame 13 is held at a neutral position with respect to the vertical direction in the figure.

Also, pitch coils 18 (partially shown in cross section in the figure) are located at the upper and lower parts of the lens holding frame 13, respectively.
is fixed, and a pitch magnet 19 and a pitch yoke 110 fixed to the first holding frame 16 are provided on both sides of the pitch coil 18 so as to sandwich it from the thickness direction (see FIG. 1(b)). By pitch magnet 1
9 and a pitch yoke 110.
By energizing and excitation of the pitch magnet 19 located in the lens holding frame 13 (therefore, the correction lens 12
) can be driven with respect to the first holding frame 16 in the pitch direction 11p, which is the vertical direction in the figure.

Note that the pitch coil 1B is provided with a slit 112, and on both sides of the pitch coil 1B, a projector 113 such as an infrared light emitting diode (IRED) fixed to the first holding frame 16 and a semiconductor detection element ( The position of the lens holding frame 13 relative to the first holding frame 16 in the pitch direction lip can be detected by a combination of a light receiver 114 such as a photodetector (pso).

The above configuration shows a configuration in which the lens holding frame 13 is supported by the first holding frame 16 in a floating manner in the pitch direction.
is floatingly supported in one direction 11y by the second holding frame 119.

That is, the first holding frame 16 is provided with a pair of yaw shafts 115 extending in one yaw direction tty at its upper and lower parts, which are connected to the housings 117, 117, which are the boss parts of the second holding frame 119. A bushing 116 made of oil-free metal is slid into a hole penetrating in the left-right direction in the figure, and the first holding frame 16 is supported so as to be slidable in the left-right direction in the figure. Thereby, the lens holding frame 13 is supported in a floating manner in the pitch direction with respect to the first holding frame 16, and is supported in a floating manner in the yaw direction with respect to the second holding frame 119.

Note that reference numerals 118 and 118 denote a pair of yaw coil springs mounted on the yaw shaft 115 in order to hold the first holding frame 6 in a neutral position with respect to the second holding frame 119.

Further, 121 is a yaw coil fixed to the first holding frame 16, which is separated from the second holding frame 11 through a spacer 124 in the thickness direction, as in the case of the pitch coil described above.
The yaw magnet 122 fixed to the frame 9 is arranged in a magnetic circuit formed by a yaw yoke (not shown), and by energizing the yaw magnet 122, the first holding frame 16 is connected to the second holding frame 119. On the other hand, it can be driven in one direction 11y, which is the left-right direction in the figure.

Note that the yaw coil 18 is provided with a slit 123, and on both sides of the slit 123, a floodlight such as an infrared light emitting diode (IRl"l) fixed to the second holding frame 119 and a semiconductor detection element (PSD) are mounted on both sides of the slit 123. ) and the like (none of which are shown), the position of the first holding frame 16 relative to the second holding frame 119 can be detected in one direction.

With the above, the lens holding frame 13 (and therefore the correction lens 1
2) is a plane perpendicular to the optical axis 0 (P-P in Fig. 1(b)
' in the plane containing the pitch direction lip and the y direction 11
y, and even when moved within the plane to control eccentricity of the optical axis to suppress image blur, there is no movement in the optical axis direction.
This has the effect of not causing the so-called out-of-focus problem.

In addition, as described above, the correction lens 12 is moved in two orthogonal axes directions (11p, 11y) using the pitch shaft and yaw shaft.
), the size of the mechanism in the optical axis direction can be reduced compared to conventional correction optical mechanisms, and this allows the image blur suppression system to be incorporated into the camera without increasing the size of the camera or lens. It also has the effect of being able to.

It goes without saying that the present invention is not limited to the embodiments described above, and can be carried out in various modified forms.For example, in the embodiments described above, for floating support in the pitch direction or in the yaw direction. A pair of shafts are used for each shaft, and in addition to using one shaft for movable support, a structure is adopted to restrict rotation around this axis, and a structure is used to control the movement. It is also possible to use only one pitch coil and one yaw coil, or to use a voice coil. Furthermore, instead of using a slide bearing structure that uses a shaft to support the correction lens in a floating manner, the lens holding frame to which the correction lens is fixed is slidably held between sliding plates placed on both sides in the optical axis direction. It is also possible to do this.

[Effects of the Invention] As explained above, the image blur suppressing device according to the present invention has a correction optical mechanism that decenters the optical axis in order to suppress image blur without imparting an '8111I component in the optical axis direction to the correction lens. Since the structure allows floating support, there is an effect that there is no problem of out-of-focus when suppressing image blur.

Furthermore, since the correction optical mechanism can be configured to have a smaller size in the optical axis direction, there is an effect that the camera can be made smaller.

[Brief explanation of drawings]

FIG. 1(a) is a front view including a partial cross section showing an outline of the configuration of the correction optical mechanism of the image blur suppressing device of the present invention, and FIG.
b) is a longitudinal sectional view taken along line A-A in FIG. 1(a). FIG. 2(a) is a perspective view illustrating a conventional example of a correction optical mechanism, FIG. 2(b) is a diagram illustrating the state at the time of optical eccentricity,
FIG. 3(a) is a perspective view illustrating another example of the conventional correction optical mechanism, FIG. 3(b) is an enlarged view of a part of the correction optical mechanism, and FIG. 3(c) is an enlarged view of a part of the correction optical mechanism. FIG. 3(d) is an enlarged view illustrating the driving means for suppressing image blur, and is a diagram illustrating the state when the optical axis is decentered. FIG. 4 is a perspective view for explaining the outline of an image blur suppression system in a conventional camera. 12: Correction lens 13: Lens holding frame 16: First holding frame 119: Second holding frame 14, 116: Sliding bearings 18, 121: Drive coil Fig. 2(b) Fig. 3 and 4 others 3rd ( a) Figure 13p Figure (b) 10

Claims (1)

[Claims] 1. Based on the detection information of vibrations generated in the lens barrel, the amount of correction for optical axis eccentricity necessary to suppress image blur on the image plane is determined, and An image blur suppression device for a camera that controls the movement of a correction optical system that is floatingly supported so as to be movable in accordance with the amount of correction, wherein the floating support of the correction optical system is supported in a plane perpendicular to the optical axis. a first holding frame that supports the correction optical system so as to be movable in a first direction defined within the plane, but restrains movement in other directions; and a second direction that is different from the first direction within the plane. The lens has a second holding frame that movably supports the second holding frame but restricts movement in other directions, and the second holding frame is fixed to the lens barrel. Image stabilization device for cameras. 2. In claim 1, the support means that movably supports the correction optical system and the first holding frame, and the support means that movably supports the first holding frame and the second holding frame are mutually An image blur suppression device for a camera, characterized in that a slide shaft extending from one of the interlocking members is slidably fitted to a bearing provided on the other. 3. The image blur suppressing device for a camera according to claim 1 or 2, wherein the first direction and the second direction are perpendicular to each other.