JPH03214114A - Image blur suppressing device for camera - Google Patents

Abstract

PURPOSE:To input even information on play as control information and to suppress an image blur of the camera with high accuracy by providing a 2nd movement control means which holds a lens holding frame at a predetermined position with the outputs of a 2nd and a 3rd position detecting means. CONSTITUTION:The lens holding frame 46 is provided with a position detection sensor 11 which consists of a magneto-resistance element, etc., nearby, for example, a bearing 44y in addition to a conventional image blur suppressing device to form a 3rd position detecting means and its output signal is added to a command signal 417y. This position detection sensor 11 detects the distance in a yaw direction 42 between a fixed frame 43 and the lens holding frame 46, i.e. the actual position in the range of the play 419. Its detected value is added to the command signal 417y and the resulting signal is inputted to a coil 48y to move the lens holding frame 46 in the yaw direction 42y, thus absorbing the play 419 substantially. Consequently, even if there is a gap 418 between a pitch slide shaft 45p and the bearing 44p, the accurate image blur suppressing device which can be considered to have no play 419 is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is installed in a camera that receives vibrations at a relatively low frequency, detects vibrations such as camera shake, and uses this information to eliminate the above-mentioned vibrations. The present invention relates to an image blur suppression device for a camera.

[Conventional technology]

Modern photographic equipment, especially cameras, have automated almost all of the functions necessary for photographing, such as determining exposure and focusing, and the number of failures in photographing due to the functions of the camera itself is extremely low.

For this reason, recent efforts have been made to develop cameras that automatically suppress photographing failures due to causes other than the camera, such as blurring of photographed images due to vibrations such as camera shake.

This camera shake is a relatively low-frequency vibration of 1 to 12 Hz that usually occurs when a camera shutter is released, but in order to prevent blurring in the photographed image even if such vibration is received, It is necessary to detect the vibration of the camera due to camera shake, and use that information to accurately and quickly drive a means for correcting the camera shake.

Such a correction means includes, for example, a vibration detection means that detects vibrations generated in the lens barrel due to camera shake, a calculation means that converts the output from the vibration detection means into a correction amount for displacing the correction optical system, and a correction means. Camera image blur suppression including a support means for supporting the optical system so as to be movable in the radial direction with respect to the lens barrel, a movement control means for moving the correction optical system by the above displacement amount and holding it at a predetermined position, etc. This is realized by the device.

FIG. 5 is a perspective view showing part of a conventional camera that employs such an image blur suppression device, in which an angular velocity meter is used as a vibration detection means, and an analog integration circuit is used as a calculation means to integrate the detected amount. Based on this displacement, the camera shake is corrected by moving the correction optical system or its supporting means using a movement control means such as a magnetic circuit, and the image on the image plane looks better. The image is kept stationary to suppress image blur.

In the figure, 51p and 51y are lens barrels 5, respectively.
Indicates the direction of vertical and horizontal shake of 2, 54p and 54y
indicate the directions of the angular velocities of vertical shake and horizontal shake, respectively.

Note that the symbol p attached to the numbers below stands for vertical pitch (pitc
h)) direction, the symbol y indicates the lateral (yaw (ya stomach)) direction.

The above angular velocities are detected by angular velocity meters 53p and 53y fixed to the lens barrel 52, respectively, and the signals are integrated by analog integration circuits 55p and 55y, respectively, and converted into displacement values to be corrected. The correction optical system 56 is moved by the output signal of this displacement value, image blur is suppressed, and an image is stably formed on the image plane 59.

Note that 57p and 57y are vertical and horizontal movement control means of the correction optical system 56, respectively, and 58p and 58V are vertical and horizontal position detection means, respectively.

There is also a device in which the image blur suppressing device itself has a mechanical integration function and the analog integration circuit described above is omitted.

FIG. 4(a) shows one of the conventional image blur suppressing devices as described above.
4(b) is a front view of the image blur suppressing device in FIG. 4(a), FIG.
c) and FIG. 4(d) are enlarged views of the pitch slide shaft portion of FIG. 4(b), respectively.

The image blur suppressing device shown in FIG. 4(a) is configured to move the correction lens 41 forming the correction optical system in two directions perpendicular to the optical axis and orthogonal to each other (a first direction, which is a pitch direction 42p, and a second direction, which is a yaw direction). By moving in the direction 42y), the optical axis is decentered and image blur is suppressed.

The members and means related to the correction in the pitch direction 42p of the image blur suppressing device include the correction lens 41, a fixed frame 43 that fixedly holds the correction lens 41, a lens holding frame 46 that holds the fixed frame 43 in a floating manner, and the like. , a first position detecting means for detecting the position of the fixed frame 43 in the pitch direction 42p, and a first magnetic circuit that moves the fixed frame 43 in the pitch direction 42p; It is a first movement control means or the like that amplifies the output and adds it to the command signal output from the analog integration circuit 55p and returns it to the first magnetic circuit to hold the correction lens 41 at a predetermined position.

The pitch slide shaft 45p provided on the fixed frame 43 is fitted and supported by sliding bearings 44p made of oil-less metal or the like provided on the lens holding frame 46 at two positions in the vertical direction. Although it can slide, it is restricted from moving in other directions.

Also, the fixed frame 43 is coaxial with the pitch slide shaft 45p.
The support is made floating by the elasticity of a pitch coil spring 47p provided between the lens holding frame 46 and the lens holding frame 46.

Furthermore, for example, the pitch direction 42p shown in FIG. 4(b)
In order to move the correction lens 41 smoothly, a gap 418 shown in FIGS. 4(c) and 4(d) is provided at the contact area between the pitch slide @ 45p and the bearing 44p, so that the fixed frame 43 can easily slide. It is.

The magnetic means for moving the fixed frame 43 in the pitch direction 42p is
A first magnetic circuit composed of pitch magnets 49p,
and a pitch coil 48p provided on the fixed frame 43 and placed in the magnetic circuit, and by passing current through the pitch coil 48p and magnetizing it, the correction lens 41 is moved in the pitch direction 42p. , correction in the pitch direction is performed.

The first position detection means for detecting the position of the fixed frame 43 in the pitch direction 42p includes a slit 410p provided on the peripheral edge of the fixed frame 43 in the pitch direction, a floodlight 41111 fixed to the lens barrel (for example, an infrared light emitting device) diode IRED)
, and a light receiver 412p (for example, a semiconductor device detection element PSD), etc., and detects the position where the light from the light emitter 411p passes through the slit 410p and enters the light receiver 412p, and from this detects the fixed frame relative to the lens barrel 52. 43 in the pitch direction 42p.

Further, each member and means related to the correction in the y direction 42y of the image blur suppressing device includes a fixed body 413 that supports the lens holding frame 46 in a floating manner, and a position of the lens holding frame 46 in the y direction 42y. A second position detecting means for detecting the lens holding frame 46 includes a second magnetic circuit that moves the lens holding frame 46 in the yaw direction 42y, and amplifies the output of the second position detecting means and uses the command signal from the analog integrating circuit. Add the second 6
11, and is a second movement control means for holding the correction lens 41 at a predetermined position.

The yaw slide shaft 45y provided on the lens holding frame is fitted and supported by sliding bearings 44Y made of oil-less metal or the like provided on the fixed body 413 at two positions in the horizontal direction. It can slide, but is restrained from moving in other directions.

Further, the support is made floating by the elasticity of a yaw coil spring 47Y provided coaxially with the yaw slide shaft 45y and between the lens holding frame 46 and the fixed body 413.

The magnetic means for moving the lens holding frame 46 is composed of a second magnetic circuit constituted by a yaw magnet 49y, a yaw coil 48Y provided in the lens holding frame 46, and disposed within the magnetic circuit. By applying current to the yaw coil 48V and magnetizing it, the lens holding frame 46 is moved in the yaw direction 42Y, and correction in the yaw direction is performed.

The position detection means for detecting the position of the lens holding frame 46 in the lateral direction 42y includes a slit 4toy provided at the peripheral edge of the lens holding frame 46 in the lateral direction, a light projector 411y fixed to the lens barrel (for example, an infrared light emitting diode TRED)
, and a light receiver 412y (for example, a semiconductor device detection element pso), and by detecting the position where the light from the light emitter 411y passes through the slit 4toy and enters the light receiver 412y, the lens holding frame is attached to the fixed body 413. The relative position of 46 in one direction 42y is detected.

To move the correction lens and lens holding frame, the output of the optical receiver is amplified by an amplifier and returned to the magnetic circuit, and in a stable state where the output of the optical receiver is almost zero, a command signal is sent to this system (
This is done by applying the above-mentioned angular displacement signal).

That is, in this example, the output of the light receiver 412p is amplified by the amplifier 414p, the compensation circuit 415p, the drive circuit 41
6p and is input to the pitch coil 48p, the fixed frame 43 is moved, the direction of the light passing through the slit 410p changes, and therefore the output of the light receiver 412p changes. Here, if the polarity of the coil 48p (and therefore the driving direction of the fixed frame 43) is set in a direction in which the output of the light receiver 412p becomes smaller, a so-called closed loop system is formed in the pitch direction, and in this system, the output of the light receiver 412p is approximately A stable state is reached when it reaches zero. In this stable state, when a command signal 417p is externally applied to such a system, the correction lens 41 is moved in the pitch direction 4211 in faithful accordance with the command signal 417p.

Further, the movement of the lens holding frame 46 in the horizontal direction 42y is similar to the movement of the fixed frame 43 in the pitch direction 42p, and the movement of the lens holding frame 46 in the pitch direction 42p includes the light receiver 412y, the amplifier 414y, and the compensation circuit 415y.
When a command signal 417y is externally applied to a stable system including a drive circuit 416y and a coil 48y, the lens holding frame 46 faithfully follows the command signal 417y and moves in one direction 42y.
be moved by

Note that the compensation circuits 415p and 415y in FIG. 4(a) are circuits for further stabilizing the above system, and the drive circuits 416p and 4iay are circuits for supplementing the current applied to the coils 48p and 48y.

[Problem to be solved by the invention] However, in the above example, for example, FIG.
As shown in Figure (d), since a gap 418 is provided in the bearing portion so that the fixed frame 43 can easily slide, there is play (backlash) between the pitch slide shaft 45p and the bearing 44p corresponding to this gap. 419 has occurred.

Therefore, when the correction lens 41 is moved in the yaw direction 42yL for the purpose of correcting camera shake in the yaw direction 42Y, the lens holding frame 46 is moved in the yaw direction 42yL, but the moving distance of the correction lens 41 is This has the disadvantage that an error of up to 419 degrees of play than the commanded υ movement distance occurs, and the desired movement accuracy cannot be obtained.

Furthermore, even in the case of shooting where there is no need to correct camera shake, the correction lens may be moved in one direction (42Y) by the maximum amount of play due to, for example, an impact caused by the mirror flipping up at the time of release, causing unnecessary correction. This has the disadvantage of causing image blur.

Furthermore, in order to reduce the play, it is necessary to improve the assembly precision of the image blur suppressing device, which has the disadvantage of making it unsuitable for mass production.

An object of the present invention is to solve the problems of the conventional image blur suppressing device as described above, and to incorporate information about the play into control information through control such as detecting the play and adding it to the command signal. An object of the present invention is to provide a highly accurate image blur suppression device for a camera.

[Means for Solving the Problems] The first feature of the image blur suppression device of the present invention that achieves the above object is to suppress image blur on the image plane based on detection information of imaging occurring in the lens barrel. The amount of correction required for optical axis eccentricity to be suppressed is determined, and the movement of the correction optical system, which is floatingly supported on the lens barrel, is controlled based on the amount of correction, so that the appearance of the image on the image plane is corrected. In an image blur suppression device for a camera that is kept stationary,
a second direction that is movable in a first direction defined in a plane perpendicular to the optical axis but is restrained from moving in other directions; The lens holding frame is movable in the direction of the correction optical system, but is restrained from movement in other directions, and is floatingly supported on the lens barrel. a first position detection means for detecting the position in the first direction; a first movement control means for holding the correction optical system at a predetermined position based on the output of the first position detection means; and a lens holding frame. a second position detecting means for detecting the position of the lens holding frame in the second direction, a third position detecting means for detecting the relative position of the lens holding frame with respect to the correction optical system, and these second and third position detecting means. The second movement control means is provided for holding the lens holding frame at a predetermined position by the output of the means.

Roughly speaking, the second feature of the image blur suppressing device of the present invention is that it calculates the amount of correction for optical axis eccentricity necessary to suppress image blur on the image plane based on the detection information of vibration generated in the lens barrel. In an image blur suppression device for a camera, the correction optical system, which is floatingly supported on the lens barrel, is moved and controlled based on the correction amount, so that the image on the image plane appears to remain still. supports the correction optical system by being movable in a first direction defined in a plane perpendicular to the plane but restraining movement in other directions, and in a second direction different from the first direction; The lens holding frame is floatingly supported on the lens barrel and is movable in the direction of the lens, but is restrained from moving in other directions. a first position detection means for detecting the position in the direction of the correction optical system; a first movement control means for holding the correction optical system at a predetermined position by the output of the first position detection means; a second detecting position in a second direction;
and a second movement control means for directly or indirectly holding the correction optical system at a predetermined position based on the output of the second position detecting means.

In the above, "directly" refers to direct movement control between the lens holding frame and the correction optical system, and "indirectly" refers to, for example, movement control between the lens barrel and the lens holding frame. This refers to the case where the correction optical system supported by this lens holding frame is moved.

[Function] According to the present invention configured as described above, the bearing supporting the correction lens can incorporate information on the play of the portion into the command signal for driving the correction lens, thereby increasing movement accuracy.

[Example] The present invention will be described in detail below based on an example shown in the drawings. Hereinafter, in ii, Figures 2 and 3, Figure 4 (a)
) The same reference numerals will be used for elements common to those of the conventional example, and detailed explanations will be omitted.

Embodiment 1 FIG. 1 is a perspective view showing an embodiment of the image blur suppressing device of the present invention.

In addition to the conventional image blur suppressing device shown in FIG. 4(a), the image blur suppressing device of this example further includes a third position detection means made of a magnetoresistive element, etc., in the vicinity of the bearing 44M. A position detection sensor 11 is provided on the lens holding frame 46,
The structure is such that the output signal is added to the command signal 417y.

This position detection sensor 11 detects the distance in the horizontal direction 42Y between the fixed frame 43 and the lens holding frame 46, that is, as shown in FIG.
) or the actual position in the plane of the play 419 shown in FIG. 4(d) is detected. The play 419 is substantially absorbed by adding this detected value to the command signal 417y and manually applying it to the coil 48y to move the lens holding frame 46 in one direction 42y.

Therefore, even if there is a gap 418 between the pitch slide shaft 45p and the bearing 44p, an image blur suppressing device with high precision can be obtained as when there is no play 419.

Embodiment 2 FIG. 2 is a perspective view showing a second embodiment of the image blur suppressing device of the present invention.

In the above conventional example, the slit 410y for detecting the position of the lens holding frame 46 in one direction 42y is connected to the lens holding frame 46.
However, in this example, the slit 41 is
0y is removed, and instead, a slit 21y for detecting the position of the fixed frame 43 in the horizontal direction 42y is provided, or a slit 21y is provided on the fixed frame 43 near the bearing 44M.

The light beam from the projector 411p is transmitted through the slit 21y.
The output is sent to the optical receiver 4!2y through the amplifier 4.
14y, a compensation circuit 415y, and a drive circuit 416y.

By adopting a position detection means with such a structure,
Since the detected position of the fixed frame 43 is a value that includes play, a highly accurate image blur suppressing device can be obtained.

Embodiment 3 FIG. 3 is a perspective view showing a third embodiment of the image blur suppressing device of the present invention.

In the image blur suppression device of Example 2, the lens holding frame 46
A yaw coil 48y for moving the lens holding frame 46 is provided at the end of the lens holding frame 46 in the y direction 42y, whereas in this example, the yaw coil 48y is removed, and instead a yaw coil 31y for moving the lens holding frame 46 is attached to the fixed frame 43. One direction 42
The second magnetic circuit is provided at the end of the V and the second magnetic circuit is connected to the fixed frame 4.
The structure is such that it directly moves 3.

By the way, in the structure shown in Example 2 above, the slit 2
The fixed frame 43 in which 1y is provided is a lens holding frame 45
and the yaw coil 48. via the yaw coil spring 47y. Y
are elastically connected.

However, in such a structure, since the movement of the slit 21y in the yaw direction 42y by the yaw coil 48y is performed elastically via the lens holding frame 46, the direction of movement and the detection phase are not the same, and the yaw coil 48y moves the slit 21y in the yaw direction 42y. Control for changing the polarity of 4UI in a direction that reduces the output of the light receiver 412y may become unstable.

However, with the structure of this example, since the connection between the yaw coil 31y and the slit 21y is inelastic, the polarity of the yaw coil 4831 can be stably controlled, and the movement can be performed without being affected by the play. A highly accurate image blur suppression device can be obtained.

[Effects of the Invention] As explained above, according to the present invention, the actual positional relationship between the linking members is directly detected within the range of play that occurs in the sliding bearing portion of the image blur suppressing device, or such slipping is detected. By directly detecting the position of the correction lens without being affected by play in the bearing and incorporating this detected information into the command signal of the image blur suppression device, an image blur suppression device with high movement accuracy can be obtained. There is.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a first example of an image blur suppressing device according to the present invention, FIG. 2 is a perspective view of a second example, and FIG. 3 is a perspective view of a third example. Further, FIG. 4(a) is a perspective view illustrating the structure of an example of a conventional image blur suppressing device, and FIG. 4(b)
), FIG. 4(C), and FIG. 4(d) are partially enlarged views, and FIG. 5 is a perspective view of an example of a conventional device for suppressing vertical and horizontal camera shake. 11...Position detection sensor 21y...Slit 31y...Yaw coil 4
8y41...Correction lens 429...Pitch direction 42y...Y direction 43...Fixed frame 44p
...Slide bearing 44y...Slide bearing 45p.
...Pitch slide axis 45y...Yaw slide axis 46...Lens holding frame 47p...Pitch coil spring 47y...Yaw coil spring 48p...Pitch coil 48y...Yaw coil 4
9p...Pitch magnet 49Y...Yaw magnet Sip...Vertical shake sty...Horizontal shake 52.
...Lens barrel 53p, 53y...Angular velocity meter 54p...Vertical shake angular velocity direction 54M...Vertical shake angular velocity direction 55p, 55y...Analog integration circuit 57p, s7y
...Movement control means sap, say...Position detection sensor 59...Image plane 410p, 410y...Slit 411p, nly...Emitter 412p, 412y...Light receiver 414p, 414y...Amplifier H5p, 415y... Compensation circuit 416p, 416y... Drive circuit 417p, 4t7y... Command signal 418... Gap 419... Play and 4 others Figure (c) 5p

Claims (1)

[Claims] 1. Based on the detected information on vibrations occurring in the lens barrel, the amount of correction for optical axis eccentricity required to suppress image blur on the image plane is determined, and In an image blur suppression device for a camera that controls the movement of a supported correction optical system based on the correction amount to make an image on an image plane appear stationary, a first supports the correction optical system while being movable in this direction but restraining movement in other directions, and movable in a second direction different from the first direction but in other directions; constitutes floating support for the correction optical system by a lens holding frame which is restrained and supported in a floating manner by the lens barrel, and a first position for detecting the position of the correction optical system in the first direction. a detection means, a first movement control means for holding the correction optical system at a predetermined position based on the output of the first position detection means, and a second movement control means for detecting the position of the lens holding frame in the second direction. position detecting means, a third position detecting means for detecting the relative position of this lens holding frame with respect to the correction optical system, and positioning of the lens holding frame at a predetermined position based on the outputs of the second and third position detecting means. An image blur suppression device for a camera, comprising: second movement control means for holding the camera. 2. Based on the detected information on vibrations occurring in the lens barrel, the amount of correction for optical axis eccentricity required to suppress image blur on the image plane is determined, and the correction optics, which is floatingly supported on the lens barrel, In an image blur suppression device for a camera that controls the movement of a system based on the correction amount to make an image on an image plane appear stationary, the system is movable in a first direction determined in a plane perpendicular to the optical axis. The correction optical system is supported by a lens mirror that is movable in a second direction different from the first direction but is restrained from moving in other directions. A lens holding frame floatingly supported by a cylinder constitutes floating support for the correction optical system, and a first position detection means for detecting the position of the correction optical system in the first direction; a first movement control means that holds the correction optical system at a predetermined position based on the output of the first position detection means; a second position detection means that detects the position of the correction optical system in the second direction; An image blur suppressing device for a camera, comprising: second movement control means that directly or indirectly holds the correction optical system at a predetermined position based on the output of the second position detection means.