JPH03186824A - Vibration isolator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention is installed in equipment such as a camera, and
The present invention relates to an image stabilization device that detects vibrations (camera shake) with a frequency of about 2 Hz and uses this information as image blur prevention information to prevent image blur, and particularly relates to improvements in its correction optical mechanism.

(Background of the Invention) The conventional technology to which the present invention is applied will be explained below using a camera as an example.

In modern cameras, all important tasks for photography, such as exposure determination and focus adjustment, are automated, so even those who are inexperienced in operating the camera are less likely to make a mistake in taking a picture. Failures in shooting cannot be automatically prevented.

Therefore, in recent years, research has been carried out on cameras that can prevent photographing failures caused by camera shake, and in particular, research and development are progressing on cameras that can prevent photographing failures due to camera shake.

The above camera shake usually has a frequency of 1) 12 to 12H2
However, in order to be able to take pictures without image blur even if such camera shake occurs at the time of shutter release, it is necessary to detect the camera vibration caused by the camera shake and calculate the detected value. The correction lens must be displaced accordingly.

Therefore, in order to achieve the above purpose (i.e., to be able to take photographs that do not cause image blur even when camera shake occurs), it is necessary to accurately detect camera vibration and to accurately displace the correction lens. becomes.

In principle, camera shake is detected by equipping the camera with 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:

Here, an outline of an image pre-suppression system using an angular velocity meter will be explained with reference to FIG.

In the example of FIG. 8, vertical camera shake 61p in the direction of arrow 61 is shown.
and a diagram of a system for suppressing camera lateral shake 61y. In the figure, 62 is a lens barrel, and 63p and 63y are angular velocity meters for detecting the vertical and horizontal angular velocities of the camera, respectively, and the respective angular velocity detection directions are indicated by 64p and 64y. 6sp and esy are well-known analog integration circuits, which integrate the signals of the angular velocity meters 63p and 63y, convert them into hand play angular displacement, and use the signals to control the correction optical system 66 (63y).
7p, 67; y drive their respective drive units; 68p, 68y drive the correction optical position detection sensors) to ensure stability on the image plane 69. Incidentally, it is also possible to provide the correction optical mechanism itself with a mechanical integration function and omit the above-mentioned analog integration circuit.

9(a) and 9(b) are structural diagrams of a correction optical mechanism suitably used in such a system, in which the correction lens 52 is operated in two mutually perpendicular directions (pitch direction 51p and yaw direction 51y). It can be driven freely. Its configuration is shown below. In addition, FIG. 9(b) represents the upper part in the figure from the optical axis of FIG. 9(a) by the AA cross section, and the lower part from the optical axis represents the side surface from the C direction. Also, in FIG. 9(a), the second holding frame 515 on the left side of the figure shown in FIG. 9(b),
The projector 512p and pitch magnet 59p are omitted to avoid complication of the drawing.

In FIGS. 9(a) and 9(b), the fixed frame 53 holding the correction lens 52 is mounted on a sliding bearing 54 made of oil-less metal or the like.
It is possible to slide on the pitch slide shaft 55p via the pitch slide shaft 55p. Further, the pitch slide shaft 55p is attached to the first holding frame 56.

The fixed frame 53 is held between pitch coil springs 57p coaxial with the pitch slide shaft 55p, and is held near the neutral position.

A pitch coil 58p is attached to the fixed frame 53.

The pitch coil 58p is placed in a magnetic circuit composed of a pitch magnet 59p and a pitch yoke 510p, and the fixed frame 53 is driven in the pitch direction 51p by passing a current.

The pitch coil 58p is provided with a slit 511P, and the projector 512p (infrared light emitting diode IRED
) and a light receiver 5131) (semiconductor device detection element psD) detect the position of the fixed frame 53 in the pitch direction 51p via the slit 511p.

A yaw slide shaft 55y is attached to the first holding frame 56, and a sliding bearing 543/
can slide inside the housing 514 into which it is fitted. Since the housing 514 is attached to the second holding frame 515, the first holding frame 56 is movable in one direction 51y relative to the second holding frame 515. Also, yaw slide axis 55y
A yaw coil spring 57y is provided coaxially with the fixed frame 53, and is held near the neutral position similarly to the fixed frame 53.

The first holding frame 56 is provided with a yaw coil 58y, and in relation to the yaw magnet 59y attached to the second holding frame 515 and the yaw yoke 5]Oy, the first holding frame 56 is moved in the yaw direction 51y. Driven.

A slit 511y is provided in the yaw coil 58y, and like the fixed frame 53, the yaw coil 58y is provided with a slit 511y in the yaw direction 51 of the first holding frame 56.
Detect the position of y.

Pitch direction 51y and yaw direction 5t of the correction lens 52
The drive system for Y has the configuration shown in FIG.

In FIG. 10, the outputs of photoreceivers 513p and 513y are amplified by amplifiers 516p and 516y, and then passed through a compensation circuit 517p.

517y and drive circuits 518p and 518y to the coils (pitch coil 58p, yaw coil 58y), the fixed frame 53. The first holding frame 56 is driven to change the outputs of the light receivers 513p and 513y. Here, if the driving direction (polarity) of the coils 58p and 58y is set in the direction in which the outputs of the light receivers 513p and 513y become smaller, a closed system shown by broken lines 520p and 520y is formed, and the outputs of the light receivers 5]3p and 5t3y are becomes stable when it becomes almost zero. Note that the compensation circuit 5]7
P and 517y are circuits for further stabilizing the system shown in FIG. 10, and drive circuits 518p and 5tay are circuits for supplementing the current applied to the coils 58p and 58y.

Command signals 519p and 519y are sent to such a system from the outside.
When given, the correction lens 52 is driven in the pitch direction 51p and the yaw direction 51y extremely faithfully to the command signals 519p and 519y.

However, in the above-mentioned conventional correction optical mechanism, in order to perform the drive smoothly, the edge bearings 54p, 54
A certain amount of clearance is required between y, the pitch, and the yaw slide axes 55p and 55y, and this clearance causes the following problems.

In FIG. 11(a), when a current is passed through the pitch coil 58p on the fixed frame 53, a thrust force 520p is generated, and the fixed frame
3 is driven upward in the paper. However, at this time, if the friction of either of the two pitch slide shafts 55pR, 55pL is even slightly large, for example, the pitch slide shaft 55pR
The friction of the slide bearing 54p is the pitch slide shaft 55pL.
, the fixed frame 53 rotates in the direction of arrow 522. Then, strain occurs between the pitch slide shaft 55pR and the slide bearing 54p, which not only makes it impossible to drive smoothly, but also damages the portion of the pitch slide 55pR shown by arrow A. Then, as the damage expands, the strain becomes more severe, and eventually it becomes impossible to drive.

Moreover, when driving is not performed, for example, the pitch coil 58p
Immediately after cutting off the current, the fixed frame 53 tries to return to the position where the gravity and the pitch coil spring 57p are balanced (as indicated by the arrow 51).
pd direction). At this time, if the friction between the pitch slide shaft 55pR and the slide bearing 54p is larger than that of the pitch slide shaft 55pL, the fixed frame 53 will rotate in the opposite direction to the arrow 522, causing damage to the arrow B of the pitch slide shaft 55pR. .

The same thing happens when you don't use the anti-vibration system at all. The fixed frame 53 is supported by a pitch coil spring 57p when the pitch coil 58p is not energized, and freely vibrates in response to external input (such as camera shake or vibration when carrying the camera). And during that time, the above-mentioned strain is constantly occurring,
The pitch slide shaft 55p is being damaged.

Furthermore, as shown in the sectional view of the fixed frame 53 in FIG. 11(b), rotation 523 occurs in the fixed frame 53, which impedes smooth driving.

Although the above-mentioned problem was described only in the pitch direction 51p, the same problem occurs when driving in the yaw direction 51y, and the yaw slide shaft 55y is damaged, making smooth driving impossible.

(Object of the Invention) An object of the present invention is to solve the above-mentioned problems, to enable a driven member to slide smoothly on a first slide shaft, and to prevent the first slide shaft from being damaged. It is an object of the present invention to provide a vibration isolating device that is capable of reducing vibrations.

(Characteristics of the Invention) In order to achieve the above object, the present invention provides: The thrust center of the means is made to coincide with the axis of the first slide shaft, so that excessive friction is applied to one end of the contact surface between the first slide shaft and the driven member. It is characterized by being made so that it does not get twisted.

(Embodiment of the Invention) FIG. 1 shows a first embodiment of the present invention, and the same elements as in the conventional example are given the same reference numerals.

The difference between the conventional example shown in Fig. 1 and Fig. 6 is that both the pitch slide shaft 55p and the yaw slide shaft 55y are now one, and the pitch slide shaft 55p and yaw slide shaft 55y are now one, and the voice coil-like pitch A coil 58p and a yaw coil 58y are provided. Also, pitch coil 58p, yaw coil 5
Since 8y is shaped like a voice coil, each voice coil has a pitch magnet 59 with a repelling polarity as shown by the arrow.
p, yaw magnets 59y are arranged to face each other.

In such a configuration, the fixed frame 53 is connected to the pitch slide shaft 5.
Since it can be rotated around 5p (arrow 13p), the first
A stopper 11 is provided between the holding frame 56 and the rotation.

Similarly, the first holding frame 56 is provided with a convex portion 12 which is brought into contact with a second holding frame (not shown) to prevent the first holding frame from rotating around the yaw slide axis 55y (arrow 13y). There is.

Housing 514 and pitch, yaw magnet 59p,
59;y, emitter 512p, 5t2y, receiver 5
13p and 513y are fixed to a second holding frame (not shown).

With this configuration, as shown in FIGS. 2(a) and 2(b), the total center of gravity of the fixed frame 53, correction lens 52, etc. and the thrust center of the pitch coil 58p are aligned with the pitch slide shaft 5.
5p, and the fixed frame 53 of the above-mentioned conventional example does not rotate, so smooth driving can be performed without prying, and there is no damage to the slide shaft 55p. Moreover, a pitch slide shaft 55 is disposed within the bobbin of the pitch coil 58p in the form of a voice coil.
Since the slide bearing 54p is provided, it can be made extremely combust.Although it is impossible to make the centers of gravity coincide with each other in the yaw direction 51.y, the thrust center of the yaw coil 58y is aligned with the yaw slide axis. 55y.

FIG. 3 shows a second embodiment of the present invention, in which only the driving section in the pitch direction is shown.

3, the difference from FIG. 2(a) is that the correction lens 52 and the fixed frame 53 are offset from the pitch slide axis 55p, and the center of gravity is not on the pitch slide axis 55p. However, the counterweight 21 is provided on the opposite side of the fixed frame 53 across the pitch slide shaft 55p, and the correction lens 52° fixed frame 53. The mass of the counterweight 21 is adjusted so that the total center of gravity of the counterweight 21 is on the pitch slide axis 55p. Therefore, both the center of thrust and the center of gravity are on the pitch slide shaft 55p, and no prying or damage to the slide shaft occurs.

In the configuration shown in FIG. 3, the correction lens 523 This is effective when the storage space is small.

In FIG. 3, the pitch coil 58p is a voice coil wound around a bobbin whose center is coaxial with the pitch slide shaft 55p, and the first one has a bearing inside the bobbin.
, is the same as the example in Figure 2.

Further, in FIG. 3, the pitch coil 58p is shown as a columnar voice coil that is long in the direction of the pitch slide axis 58p, but it goes without saying that it may be a voice coil that is short in this direction.

FIG. 4 shows a third embodiment of the invention.

In FIG. 4, the center of gravity of the correction lens 52 and the fixed frame 53 is on the axis of the pitch slide axis 55p, but the pitch coil 58p is arranged axially symmetrically to the pitch slide axis 55p. Therefore, the center of each thrust is the pitch slide axis 5
Although it is not on 5p, the total thrust center is on this axis, so
No prying or damage will occur.

FIG. 5 shows a fourth embodiment of the invention.

4 This has two pitch coils 58p as shown in FIG. 4, and the center of gravity is moved by the counterweight 21 shown in FIG.
3. The total center of gravity of the correction lens 52 and counterweight 21 and the total thrust center of the pitch coils 58p+ and 5sp2 are arranged on the pitch slide axis 55p.

Note that the counterweight 21 and the coil 581) can be used in any number and position as long as their total center of gravity and center of thrust are on the slide shaft 55p, and there is an advantage that they can be designed freely taking into consideration the storage space for the correction optical mechanism. Born.

FIG. 6 shows a fifth embodiment of the present invention.

In FIG. 6, the means constituted by the light receiver 5]3p, the amplifier 516p, the compensation circuit 5]7p, and the drive circuit 518p are the same as the control and drive system of the correction optical mechanism described so far. However, a light receiver 41p and a light emitter 42p are further provided, and the differential output from the light receiver 513p is sent to a differential amplifier 43.
p, and the rotation in the optical axis direction of the correction 1/lens 52 (generated from the difference in thrust between the pitch coils 58p1 and 58p2) is detected. Then, the output of the differential amplifier 43p is input to the drive circuit 4.49, and the pitch coil 58p2
drive and correct rotation.

Therefore, twisting and damage due to rotation will not occur.

In addition, an amplifier 516p and a compensation circuit 51 are also installed on the photoreceiver 41p side.
7p and a drive circuit 518p may be separately provided to drive the pitch coil 58p2.

FIG. 7 shows a sixth embodiment of the present invention.

Pitch coil 58p, photoreceiver 5], 3p, amplifier 51
6p, the compensation circuit 517p, and the drive circuit 518p perform drive control in the same way as before. However, the drive circuit 518
The output of p is input to the integrating circuit 45p, and the output of the integrating circuit 45p
The output of is input to the comparator 46p, and the reference voltage source 4
7 p, compared to the voltage of .

Therefore, the comparator 46p is connected to the pitch coil 58P+
If the thrust given to is a constant output for a certain period of time, it will output.

48p is an analog switch, and comparator 46p
The output of the pitch coil 58] p2 is connected to the drive amplifier 49p. Therefore, when 71", 11, etc. are generated on the slide shaft 55p, and a large thrust is required for a long period of time in the pitch coil 58p, the output of the drive circuit 5]8p is amplified as desired by the drive amplifier 49p, and the pitch coil 58p2i is amplified as desired. For example, when the pitch coil 58p1 is being driven and prying occurs, the fixed frame 53 rotates in the direction of the arrow 411 and remains stationary.
A large thrust was applied to the coil 58p1 in an attempt to move it, and continued 1. - to do. When I was with B.
...Gives thrust to Chifi J1158 p 2, arrow 41
If the structure is as shown in the embodiment shown in Fig. 6.7, in which stiffness can be eliminated by applying torque in the opposite direction to 1, the center of force can be moved to the slide axis only when necessary, and multiple coils can be used. It is possible to save power compared to providing thrust all the time.

According to this embodiment, the center of gravity of the driven part that is moved in the pitch direction, including the center of thrust in the pitch direction and the correction lens, is placed on the bitch slide or idle axis, or a counterweight is attached to move the center of gravity in the thrust direction. The drive means are placed on both sides of the slide shaft, and the center of thrust is moved to the slide shaft. This enables smooth drive without twisting, and eliminates damage to the shaft. It becomes possible. .

Also, is it possible to electrically detect when a twist is about to occur and move the center of gravity and thrust center to the appropriate position to prevent the twist? Second t-6, by installing a bearing inside the voice coil button which is the driving means,
I was able to make the above configuration extremely neat.

(Correspondence between the invention and the embodiments) In this embodiment, the pitch fill 58p1 bit magnet 59p serves as the first driving means of the present invention, and the correction lens 52. Fixed frame 53. Pitch coil 58p, floodlight 512
p corresponds to the driven portion of the first driving means.

(Effects of the Invention) As explained above, according to the present invention, the center of gravity of the total mass of the driven members including the correction lens and the fixed frame, which are driven by the first driving means, and the eleventh drive The thrust center of the means is made to coincide with the axis of the first slide shaft, so that excessive friction is applied to one end of the contact surface between the first slide shaft and the driven member. This prevents the driven member from sliding smoothly on the first slide shaft, and prevents the first slide shaft from being damaged.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the correction optical mechanism opening of the first embodiment of the present invention, FIG. 2 is a front view of the main part,
FIG. 3 is a front view showing the main parts of the second embodiment of the invention, FIG. 4 is a front view showing the main parts of the third embodiment of the invention, and FIG. 5 is a front view of the main parts of the third embodiment of the invention. FIG. 6 is a front view showing the main parts of the embodiment, FIG. 6 is a diagram showing the schematic configuration of the fifth embodiment of the present invention, FIG. 7 is a diagram showing the schematic configuration of the sixth embodiment of the present invention, and FIG. The figure is a perspective view showing a state in which a conventional mechanism is incorporated into a camera, and Fig. 9(a)
9 is a front view showing details of another conventional correction optical mechanism, and FIG. 9(b) is a cross-sectional view and a side view in the C direction,
Fig. 10 is an electrical block diagram showing a control drive system arranged in this type of device, and Figs. 11 (a) and 11 (b) are plan and cross-sectional views for explaining the problems of the conventional example shown in Fig. 9. It is. 52...Correction lens, 52...Fixed frame, 55p...Pitch slide axis, 55y...
...Yaw slide axis, 56...First holding frame, 58p...Pitch coil, 512p...
...Floodlight.

Claims (2)

[Claims] (1) A correction optical mechanism disposed within a lens barrel holding a lens group and decentering the optical axis of the lens group; a vibration detection means for detecting vibrations applied to the lens barrel; In the camera image stabilization device, the camera image stabilization device includes an image stabilization control means that drives the correction optical mechanism based on a signal from the camera and performs image stabilization. a first holding frame that supports the fixed frame with a first slide shaft so as to be slidable in a first direction different from the optical axis direction of the lens group; and a second holding frame fixed to the lens barrel and supported by a second slide shaft so as to be slidable in a second direction different from the first direction, and a second holding frame fixed to the lens barrel; a first driving means for driving in the direction;
and a second driving means for driving the first holding frame in the second direction, the driven member including the correction lens and the fixed frame being driven by the first driving means. A vibration isolating device characterized in that the center of gravity of the total mass of the vibration damping device and the center of thrust of the first driving means are made to coincide with the axis of the first slide shaft. (2) The vibration isolator according to claim 1, wherein the thrust center of the second drive means is made to coincide with the axis of the second slide shaft.