JP3768680B2 - Anti-vibration device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has optical axis decentering means for decentering the optical axis. Improvement of equipment with anti-vibration function It is about.
[0002]
[Prior art]
Since the current camera automates all the important tasks for shooting such as determining the exposure and focusing, the possibility of shooting failure is very low even for those who are unskilled in camera operation.
[0003]
Recently, a system for preventing camera shake applied to the camera has been studied, and there are almost no factors that cause a photographer to make a shooting mistake.
[0004]
Here, a system for preventing camera shake will be briefly described.
[0005]
The camera shake at the time of shooting is usually a vibration of 1 Hz to 10 Hz as a frequency. However, as a basic idea for making it possible to take a photograph without image shake even if such a camera shake occurs at the shutter release time. Therefore, it is necessary to detect the vibration of the camera due to the camera shake and to displace the correction lens in accordance with the detected value. Therefore, in order to take a photograph in which image shake does not occur even if camera shake occurs, first, it is necessary to accurately detect camera vibration and, second, to correct optical axis changes due to camera shake. Become.
[0006]
In principle, this vibration (camera shake) is detected by a shake detection sensor that detects acceleration, angular acceleration, angular velocity, angular displacement, and the like, and a calculation unit that appropriately calculates the output for camera shake correction. This can be done by mounting the equipped vibration detection device on a camera. Then, based on this detection information, image blur suppression is performed by driving correction means for decentering the photographing optical axis.
[0007]
Japanese Patent Laid-Open No. 2-58037 discloses details of the vibration detection apparatus, the correction means, and the vibration isolation system having the driving means for driving the correction means. Here, the outline thereof will be described with reference to FIG. To do.
[0008]
FIG. 18A is a perspective view of a compact camera equipped with a vibration isolation system, 61 is a camera cover, 62 is a photographing lens of the camera, and is protected by a lens barrier when not photographing (FIG. 18). (A) The lens barrier is retracted and cannot be seen because of the photographing state). Reference numeral 63 denotes a main switch of the camera. FIG. 18A shows a photographing enabled state in which the image stabilization system is turned on. When the main switch 63 is set to the index “OFF”, the photographing is disabled. When the position 64 indicating the sport mode (high-speed shutter mode) or the position 65 indicating the strobe mode is set, the image stabilization system is switched to the photographable state (because the image stabilization system is not necessary in such a mode). ). Reference numeral 66 denotes a release button. When the release button 66 is depressed, the camera performs photometry and distance measurement, and after the focusing is completed, shake correction is started and exposure to the film is performed. A strobe light emitting unit 67 automatically emits light or forcibly emits light when the subject is dark. 75 is a viewfinder optical system, and 76 is a user's eye looking into the viewfinder.
[0009]
18 (b) is an internal perspective view of FIG. 18 (a), in which 70 is a camera body, 68 is a correction means for correcting shake by driving the correction optical system 69 freely in the X and Y directions, and 71p. , 71y are shake detection sensors for detecting a shake 72p in the pitch direction and a shake 72y in the yaw direction, respectively. Reference numeral 73 denotes the lens barrier described above, which opens and closes in conjunction with the knob 74 shown in FIG. As shown in FIG. 18A, the knob 74 is adjacent to the main switch 63. When the main switch 63 is operated, the knob 74 is also pushed and the lens barrier 73 is opened. When the lens barrier 73 is in a closed state, the correction means 68 (specifically, a support frame that supports the correction optical system 69) is mechanically locked, and the correction means 68 is violently damaged when not being photographed such as when being carried. It prevents that.
[0010]
[Problems to be solved by the invention]
The correction means 68 shown in FIG. 18 (b) is electromagnetically driven in relation to the coil and magnet constituting the drive means and performs shake correction. However, the coil is disconnected due to an external impact or the like, or the magnet is If it breaks, it will not be able to drive. In addition, even when dust or the like from the outside adheres to the correction means 68 and the movement becomes worse, good shake correction cannot be performed.
[0011]
In such a case, it is necessary to inform the user that the drive for correcting the shake cannot be performed in order to promptly go out for repair. In particular, as shown in FIG. 18, in a compact camera in which the finder optical system 75 is provided independently of the photographing optical system, it is unclear whether or not the shake is normally performed even when looking through the finder. This is an essential requirement.
[0012]
However, there has been no conventional device that can detect the malfunction of the correcting means and the driving means without impairing the downsizing of the optical device such as a camera. In other words, for example, it is possible to detect a malfunction of the correction means and the drive means by providing a position detection sensor and monitoring the output of the position detection sensor, but this leads to an increase in the size and cost of the camera. It was not preferable.
[0013]
(Object of the invention) the purpose The malfunction of the optical axis eccentric means and the driving means for driving the optical axis eccentric means , Power saving and high accuracy An object of the present invention is to provide a device with an anti-vibration function that can be detected.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises an optical axis decentering means for decentering an optical axis, a driving means for driving the optical axis decentering means by a magnetic action, A constant resistance connected in series to the drive coil of the drive means, and when the voltage of the natural frequency of the optical axis eccentric means is applied to a series circuit of the drive coil and the constant resistance, Voltage Measure the When the voltage of the constant resistance is not within the voltage range generated in the constant resistance in the resonance state of the optical axis eccentric means It is determined that there is an abnormality in the operation of at least one of the optical axis eccentric means and the drive means, When in the voltage range Abnormality determination means for determining that there is no abnormality Have A device with an anti-vibration function is provided.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on illustrated embodiments.
[0029]
FIG. 1 is a block diagram showing the main part of a compact camera according to the first embodiment of the present invention, and assumes a structure having the correcting means shown in FIG. FIG. 1 shows a system with only camera vertical shake (Y-direction shake in FIG. 1, hereinafter referred to as pitch-direction shake), but the camera side shake (X-direction shake in FIG. 1) The yaw direction fluctuation is also the same configuration.
[0030]
The camera microcomputer 11 receives the state signals of the main switch 13 and the release switch 14 of the camera, the shake detection sensor 71p shown in FIG. 18, and the shake signal of the vibration detection device 10p having a calculation unit for calculating the output thereof.
[0031]
When the main switch 13 is turned on, the vibration detecting device 10p starts to detect the shake, and when the shake signal is input to the camera microcomputer 11 and the release switch 14 is pushed (actually, the release switch before that). 14 is half-pressed to perform photometry and distance measurement of the subject), the camera microcomputer 11 uses coils 68pa and 68pb via the drive circuits 12pa and 12pb on the basis of the shake signal from the vibration detection device 10p. Current is passed through. As a result, the coils 68pa and 68pb drive the correction means 68 (correction optical system 69) in the Y direction in relation to the closed magnetic circuits 68pc and 68pd to perform shake correction.
[0032]
Here, determination of whether or not the movement of the correction means 68 before shake correction is normal (hereinafter also referred to as abnormality determination) will be described.
[0033]
When the main switch 13 of the camera is turned on, the camera microcomputer 11 gives a predetermined current to the coil 68pa via the drive circuit 12pa prior to performing actual shake correction. At this time, the drive circuit 12pb is turned off. When the coil 68pa is energized, the correction means 68 is normally driven in the Y direction, and an electromotive force is induced in the coil 68pb in relation to the closed magnetic circuit 68pd. However, parts may be damaged by an external impact or the like. Thus, this electromotive force is not generated when the correction means 68 cannot move or when the coil 68pb is disconnected. Of course, since the correcting means 68 does not move even when the coil 68pa is disconnected, no electromotive force is generated.
[0034]
Therefore, the camera microcomputer 11 determines whether or not an electromotive force is generated in the coil 68pb when the coil 68pa is energized, and whether or not a signal is generated in the window comparator 15p that compares the output of the coil 68pb with a predetermined value. If the signal is not generated (no electromotive force is generated), that is, it is determined that the correction means 68 is not operating normally, the display device 16 is driven and this is indicated by sound or display. Etc. to inform the user.
[0035]
FIG. 2 is a flowchart showing the operation of only the portion of the camera microcomputer 11 that performs the state determination of the correction means 68, and will be described below.
[0036]
When the main switch 13 is turned on, the camera microcomputer 11 starts the operation of FIG. 2. First, in step # 1001, the drive circuit 12pb on the electromotive force detection side is turned off (otherwise, no electromotive force is generated). In the next step # 1002, a predetermined current is supplied to the coil 68pa to drive the correction means 68. Then, in the next step # 1003, the state of the output signal of the window comparator 15p is determined, and when the signal is inputted, the correction means 68 can move normally, so the process proceeds to step # 1004, and the coil 68pa is supplied to the coil 68pa. The energization (drive) is stopped, and the normal camera sequence is performed thereafter.
[0037]
On the other hand, if it is determined in step # 1003 that the correction means 68 cannot move normally from the output signal of the window comparator 15p, the process proceeds to step # 1005 to stop energization of the coil 68pa and the subsequent step # 1006. Then, the display device 16 is driven to notify the user of this fact.
[0038]
In this way, prior to shake correction, one of the coils 68pa is energized to drive the correction means 68, and is induced by the other coil 68pb (in normal shake correction, this coil is also used for shake correction in the pitch direction). Since the abnormality determination of the correction means 68 is performed depending on whether or not an electromotive force (counterelectromotive force) is generated, for example, compared to a method of monitoring the movement by arranging a position detection sensor or the like, A much simpler structure.
[0039]
More specifically, a relatively large precision device such as a single-lens reflex camera is provided with a position detection sensor for monitoring the movement of the correction means, and the abnormality detection is performed by using the position detection sensor. However, a small and inexpensive precision device such as a compact camera does not have a position detection sensor that is large and costly, and a method for determining abnormality of the correction means in such a device is conventionally known. Although it did not exist, the above functions can be easily added without causing an increase in the size and cost of the device by making an abnormality determination with the configuration as described above, and the effect is tremendous. It is.
[0040]
The abnormality determination is performed by driving the correction unit 68 in the Y direction. However, the abnormality determination is also performed in the direction (coil). 68yb Current is passed through the coil 68ya May be measured).
[0041]
Further, although the electromotive force from the coil 68pb is input to the window comparator 15p, the electromotive force itself may be A / D converted and taken into the microcomputer, and the determination may be made within the microcomputer.
[0042]
(Second Embodiment)
FIG. 3 is a block diagram showing main parts of a compact camera according to the second embodiment of the present invention. The same parts as those in FIG.
[0043]
1 is different from FIG. 1 in that when an abnormality is determined, an alternating current is applied to the coil 68pa to drive the correction means 68 to vibrate. It is the point which has arrange | positioned between and cuts except the said vibration drive frequency.
[0044]
As a result, the noise superimposed on the electromotive force induced in the coil 68pb is cut by the band pass filter 17p, and as shown in FIG. 4, the window comparator 15p allows the camera when the input alternating signal exceeds a predetermined range. A signal is output to the microcomputer 11 to inform that the correction means 68 is operating normally.
[0045]
With the configuration as described above, noise superimposed on the coil 68pb is cut, and the reliability of abnormality determination can be improved.
[0046]
(Third embodiment)
5 to 7 are views showing the configuration of the correcting means according to the third embodiment of the present invention, FIG. 5 is a front view of the correcting means, and FIG. 6A is a cross-sectional view taken along the line AA of FIG. FIG. 6B is a view seen from the direction of the arrow 38 in FIG. 5, and FIG. 7 is a perspective view of the correcting means shown in FIG.
[0047]
In these drawings, a correction lens 31 (as shown in FIG. 6A), the correction lens 31 is composed of two lenses fixed to a support frame 32, and a photographing optical system together with a lens 39 fixed to a base plate 35. Are configured to be fixed to the support frame 32. A yoke 33 made of a ferromagnetic material is attached to the support frame 32, and a permanent magnet such as neodymium is attracted and fixed to the back side of the yoke 33 (indicated by a hatched line in FIG. 5). Further, the three pins 32 a extending radially from the support frame 32 are fitted into long holes 35 b provided in the side wall 35 a of the main plate 35.
[0048]
As shown in FIG. 6B and FIG. 7, the relationship between the pin 32a and the long hole 35b is fitted in the optical axis direction of the correction lens 31, and no play occurs but it is long in the direction perpendicular to the optical axis. The hole extends. Therefore, although the support frame 32 is restricted in movement in the direction of the optical axis 311 with respect to the base plate 35, it can freely move (in the directions of arrows 310p, 310y, and 310r in FIG. 5) in a plane orthogonal to the optical axis. However, since the tension spring 37 is hung between the hook 32b on the support frame 32 and the hook 35c on the main plate, it is elastically restricted in each direction (310p, 310y, 310r direction). Coils 36p and 36y are attached to the ground plane 35 so as to face the permanent magnets 34p and 34y.
[0049]
Each arrangement of the yoke 33, the permanent magnet 34p, and the coil 36p is as shown in FIG. 6 (a) (the permanent magnet 34y and the coil 36y are also arranged in the same manner). When it is driven in the 310p direction and a current is passed through the coil 36y, the support frame 32 is driven in the arrow 310y direction. The driving amount is obtained by balancing the spring constant of the tension spring 37 in each direction with the thrust generated in relation to the coils 36p and 36y and the permanent magnets 34p and 34y. That is, the amount of eccentricity of the correction lens 31 can be controlled based on the amount of current flowing through the coils 36p and 36y.
[0050]
FIG. 8 is a block diagram showing a circuit configuration of a part that performs abnormality determination of a compact camera having the correcting means having the above-described configuration, and shows only a part that performs abnormality determination on one axis (in the direction of arrow 310p). The other axes (in the direction of arrow 310y) have the same configuration.
[0051]
FIG. 8 is different from FIG. 3 in that a resistor (constant resistance) 312p having a constant resistance value is connected in series to the coil 36p, and both-end outputs of the resistor 312p are input to the band-pass filter 16p. It is.
[0052]
The resistor 312p is set to about 1Ω when the resistance of the coil 36p is 20Ω, and approximately “1/21” of the voltage applied from the drive circuit 12p to the coil 36p appears between the resistors 312p. Here, the expression “substantially“ 1/21 ”is because the voltage appearing across the resistor 312p changes depending on the frequency of the voltage applied to the coil 36p.
[0053]
FIG. 9A shows the relationship of the impedance (vertical axis) of the coil 36p with respect to the frequency (horizontal axis) of the voltage applied to the coil 36p. The characteristic is determined by the spring constant of the tension spring 37 and the mass of the correction means. Frequency f ₀ , The impedance is high (see waveform 315). This is the natural frequency f ₀ Since the correction means resonates and vibrates greatly, the generation of counter electromotive force increases. Further, the higher impedance on the high frequency side is due to the inductance of the coil 36p.
[0054]
By the way, when the correction unit is broken and cannot move, resonance does not occur even when the correction unit is driven, and thus no increase in impedance at the natural frequency occurs (see waveform 316).
[0055]
In the block diagram of FIG. 8, for example, the natural frequency f is applied to the coil 36p before the start of shake correction. ₀ When the voltage is given, the voltage generated between the resistors 312p has a waveform 313 in FIG. This waveform becomes large as the waveform 314 because the impedance of the coil 36p is low when the correction means is broken.
[0056]
Therefore, it passes only near the natural frequency f0. Make After the noise is cut by the band pass filter 17p, an abnormality is determined from the output of the window comparator 15p. Specifically, when it is detected from the output of the window comparator 15p that the peak voltage across the resistor 312p exceeds the range V2 in FIG. 9B, it is determined that the correcting means is not moving, and the range V1 If the following is detected, it is determined that the coil 36p is disconnected, and in any case, the camera microcomputer 11 determines that it is abnormal, and drives the display device 16 to notify the user of this fact. On the other hand, when the peak voltage between the resistors 312p is between the range V1 and V2, it is determined that the correction means can be operated normally, and the process proceeds to a normal camera sequence.
[0057]
FIG. 10 is a flowchart showing the operation of only the portion for determining the state of the correction means of the camera microcomputer 11 according to the third embodiment of the present invention, which will be described below.
[0058]
When the main switch 13 is turned on, the camera microcomputer 11 starts the operation shown in FIG. 10, and first, at step # 3001, the release button 14 is half-pressed and waits until the switch S1 is turned on. Thereafter, when the switch S1 is turned on, the process proceeds to step # 3002, and the coil 36p has the above natural frequency f. ₀ Then, a voltage is applied to oscillate the correcting means in the direction of arrow 310p in FIG.
[0059]
In the next step # 3003, the peak voltage Vp generated in the resistor 312p at this time is taken in via the band pass filter 17p and the window comparator 15p. In the subsequent step # 3004, the peak voltage Vp of the resistor 312p is set within a predetermined range (V) from the output of the window comparator 15p. ₁ <Vp <V ₂ ), And if not, the movement of the correction means is abnormal, so that the process proceeds to step # 3006, the power supply to the coil 36p is stopped, and in the subsequent step # 3007, the display device 16 is turned on. Drive to inform the user of that.
[0060]
On the other hand, the peak voltage Vp of the resistor 312p is within a predetermined range (V ₁ <Vp <V ₂ ), The process proceeds to step # 3005 to stop energization of the coil 36p. In the subsequent step # 3008, the coil 36y is turned to the above natural frequency f. ₀ Then, the voltage is applied to oscillate the correcting means in the direction of arrow 310y in FIG. In the next step # 3009, the peak voltage Vy generated at the resistor 312y (not shown) at this time is taken in via the bandpass filter 17y and the window comparator 15y (both not shown).
[0061]
In the next step # 3010, the peak voltage Vy of the resistor 312y is set within a predetermined range (V ₁ <Vy <V ₂ ), And if not, the movement of the correction means is abnormal, so the process proceeds to step # 3012 to stop energization of the coil 36y. In the subsequent step # 3007, the display device 16 is turned off. Drive to inform the user of that. Further, the peak voltage Vy of the resistor 312y is within a predetermined range (V ₁ <Vy <V ₂ ), The process proceeds to step # 3011 to stop energization of the coil 36y and shift to a normal camera sequence.
[0062]
In the above flow, the time is shifted without simultaneously energizing the coils 36p and 36y in order to avoid the occurrence of drive interference in two directions due to energization at the same time. Note that it is not always necessary to perform both, and it is possible to determine an abnormality only by energizing one of the coils.
[0063]
In this flow, the abnormality determination operation is started when the switch S1 is turned on. Actually, the metering and distance measuring operations are also performed when the switch S1 is turned on. It may be performed prior to the distance, or may be performed after the photometry or distance measurement operation, and the abnormality determination operation may be omitted when the image stabilization is not used.
[0064]
Further, as in the first and second embodiments, the abnormality determination operation may be performed when the main switch 13 of the camera is turned on.
[0065]
Note that the time during which the coils 36p and 36y are actually energized is, for example, about 0.1 seconds, and does not give the user unpleasant feeling.
[0066]
In the third embodiment described above, the natural frequency f is applied to the coil 36p (36y). ₀ Note that the impedance of the coil 36p changes greatly depending on whether or not the corrector operates normally when a voltage of 3 is applied, and a resistor 312p (312y) is provided for detecting a change in the impedance. By measuring the voltage generated in the meantime, the abnormality of the correction means is determined.
[0067]
Therefore, even in a more compact camera that does not have two coils (for driving in the pitch and yaw directions) as in the first and second embodiments, the size and cost can be increased. It is possible to reliably determine the abnormality of the correction means without incurring.
[0068]
Further, the natural frequency f obtained from the spring constant of the tension spring 37 and the mass of the correction means. ₀ Thus, the correction means is driven to vibrate, so that a larger impedance change can be measured by applying a small current to the coil.
[0069]
(Fourth embodiment)
In the third embodiment, the correction means is driven at the natural frequency and the level of the resistance voltage at that time is measured. However, in the fourth embodiment of the present invention, the correction is performed together with the voltage level. The means is driven at a frequency equal to or lower than the natural frequency, the voltage level between the resistances at that time is also obtained, and an abnormality is determined from the relationship between the two.
[0070]
This is because the voltage generated between the resistors also changes in the shooting state (temperature, camera posture, etc.), but if the relative relationship between the two voltage levels is used as described above, the influence of the shooting state is affected. This is because there are fewer cases, and it is possible to perform highly reliable abnormality determination.
[0071]
FIG. 11 is a block diagram showing a circuit configuration related to abnormality determination of a compact camera according to the fourth embodiment of the present invention. The same parts as those in FIG.
[0072]
FIG. 11 differs from FIG. 8 in that the pass band of the band-pass filter 17p can be changed by an instruction from the camera microcomputer 11, and the signal noise-cut by the band-pass filter 17p is converted into a camera by the A / D converter 317p. This is the point taken into the microcomputer 11.
[0073]
Before performing the shake correction, the camera microcomputer 11 applies the natural frequency f to the coil 36p. ₀ Lower frequency f (eg 50 Hz) ₁ An instruction to apply a voltage at 5 Hz (for example, 5 Hz) is given, and at the same time, the characteristics of the bandpass filter 17p are changed to f ₁ Filter characteristics that pass only. And the resistance peak voltage Vpf at that time ₁ And then the natural frequency f is applied to the coil 36p. ₀ The same voltage is applied at the same time, and at the same time the bandpass filter 16p is changed to f ₀ Filter characteristic that only passes, and the peak voltage Vpf at that time ₀ Capture.
[0074]
When driven at the natural frequency f0, the impedance of the coil increases and the flowing current decreases. Therefore, Vpf0 is smaller than the peak voltage Vpf1. Become Therefore, the camera microcomputer 11 calculates “Vpf1 / Vpf0” and determines that the correction means can move normally when the value is larger than a predetermined value (for example, (Vpf1 / Vpf0) ≧ 2).
[0075]
FIG. 12 is a flowchart showing the operation of only the portion for determining the state of the correction means of the camera microcomputer 11 according to the fourth embodiment of the present invention.
[0076]
When the main switch 13 of the camera is turned on, the camera microcomputer 11 starts the operation shown in FIG. 12. First, in step # 4001, the pass frequency of the bandpass filter 17p is set to f. ₁ (For example, 5 Hz). In the next step # 4002, the frequency f is applied to the coil 36p. ₁ Is applied to drive the correction means. The impedance of the coil 36p at this time is f in FIG. ₁ R at the time ₁ And the corresponding current is f ₁ It flows in the coil 36p at a frequency.
[0077]
In the next step # 4003, the frequency f generated between the resistors 312p at that time ₁ The peak voltage Vpf obtained through the A / D converter 317p is obtained by noise-cutting the voltage of the current by the band-pass filter 17p. ₁ In step # 4004, the voltage application to the coil 36p is stopped. In the following steps # 4005 to # 4007, the same operation as the above steps # 4002 to # 4004 is performed on the coil 36y, and the peak voltage Vyf ₁ Remember.
[0078]
In the next step # 4008, the pass frequency of the bandpass filter 17p is set to f. ₀ (For example, 50 Hz). Thereafter, in steps # 4009 to # 4014, the same operations as in steps # 4002 to # 4007 are performed with the frequency f. ₀ The peak voltage Vpf obtained for the coils 36p and 36y ₀ , Vyf ₀ Is stored.
[0079]
Here, first, the frequency f ₁ And then the frequency f ₀ It is f to drive in the order of ₀ After driving, the vibration remains for a while due to resonance, and immediately f ₁ This is because it cannot be driven.
[0080]
At this time, if the correcting means is operating normally, the impedances of the coils 36p and 36y are R shown in FIG. ₀ It has become. "R ₀ > R ₁ For the coil 36p, 36y, the frequency f ₀ The coil-to-coil current that flows when a voltage of ₁ This is less than when the voltage is applied. Therefore, the peak voltage Vpf across the resistor 312p ₀ , Vyf ₀ Is "Vpf" ₀ <Vpf ₁ "," Vyf ₀ <Vyf ₁ "
[0081]
In the next step # 4015, the peak voltage Vpf ₁ And Vpf ₀ Ratio of Vpf ₁ / Vpf ₀ When this value is smaller than a certain value (for example, 2), it is determined that the correction means is abnormal, and the process proceeds to step # 4017 to drive the display device 16 to notify the user of this fact.
[0082]
Also, the peak voltage Vpf ₁ And Vpf ₀ Is larger than a certain value, it is determined that the movement of the correction means in the pitch direction is normal, and the process proceeds to step # 4016. Here, the peak voltage Vyf ₁ And Vyf ₀ Ratio of Vyf ₁ / Vyf ₀ " As a result, when this value is smaller than a certain value (for example, 2), it is determined that the correction means is abnormal, the process proceeds to step # 4017 described above, and the display device 16 is driven to notify the user of this fact. On the other hand, the peak voltage Vyf ₁ And Vyf ₀ If the ratio is greater than a certain value, it is assumed that the movement of the correcting means in the yaw direction is normal, and the process proceeds to a normal camera sequence.
[0083]
In this way, the correction means is driven at a plurality of different frequencies (natural frequency and lower frequency), and the change in the electromotive force (impedance change) induced in the coil is measured, resulting in high reliability. Abnormality determination can be performed.
[0084]
(Fifth embodiment)
The correction means shown in FIG. 1 and FIGS. 5 to 7, for example, taking FIG. 5 as an example, drives the support frame 32 in the direction of the arrow 310p when a voltage is applied to the coil 36p. However, when the drive frequency is increased and near the natural frequency, it is driven not only in the arrow 310p but also in the direction of the arrow 310y (becomes moving diagonally). Such a phenomenon is called an “interference phenomenon”, which is generally not preferable, but has a natural frequency f. ₀ Is set higher than the correction band for camera shake (the natural frequency is 50 Hz with respect to the camera shake correction band of 1 to 10 Hz), so that the camera shake correction accuracy is not affected.
[0085]
Since the support frame 32 is also driven in the direction of the arrow 310y, when the electromotive voltage induced in the coil 36y is measured, frequency characteristics as shown in FIG. 13 are obtained.
[0086]
In FIG. 13, the natural frequency f ₀ The reason why the electromotive voltage has a peak at this time is because the above-described interference increases, and a frequency lower than that (for example, f ₁ ), The electromotive voltage of the coil 36y is small because of less interference. This electromotive voltage does not occur when the coil 36p is disconnected or when the correction means is broken, because it cannot be driven, and even if the correction means can be driven, the coil 36y is disconnected or is opposed to permanent. It does not occur when an abnormality occurs in the magnet 34y.
[0087]
The fifth embodiment of the present invention pays attention to the above points, and determines the abnormality of the correcting means by measuring the electromotive force induced in the coil 36y by the interference phenomenon by driving the coil 36p. .
[0088]
FIG. 14 is a block diagram showing a circuit configuration of a main part of a compact camera according to the fifth embodiment of the present invention for realizing the above-described abnormality determination. The same parts as those in FIG. The description is omitted.
[0089]
In FIG. 14, 12p and 12y are drive circuits that drive the coils 36p and 36y during shake correction. An analog switch 51 is normally opened, but is closed by an instruction from the camera microcomputer 11 while the abnormality determination of the correction means is performed after the main switch 13 is turned on. A differential amplifier 52 amplifies the voltage across the resistance of the coil 36y. 53 is a band-pass filter (corresponding to the band-pass filter 17p in FIG. 8), which cuts (noise cuts) other than the natural frequency component of the signal from the differential amplifier 52.
[0090]
54 is a rectifier, and the frequency f from the bandpass filter 53 is shown. ₀ The signal is converted into a direct current component (DC) by, for example, converting it into an absolute value and then smoothing it. The DC signal increases as the electromotive voltage between the coils 36y increases.
[0091]
That is, when the correction means is normal, the frequency f is applied to the coil 36p. ₀ When the correction means is driven by applying the voltage of, the rectifier 54 outputs a high potential, but when the correction means is abnormal, the output of the rectifier 54 becomes low potential or no output.
[0092]
The window comparator 55 arranged in the next stage outputs a signal Va indicating that the correction means is normal to the camera microcomputer 11 if the signal from the rectifier 54 is a certain value or more.
[0093]
In FIG. 14, the signal from the differential amplifier 52 may be A / D taken into the camera microcomputer 11 and the subsequent processing may be performed by the camera microcomputer 11.
[0094]
FIG. 15 is a flowchart showing the operation of the part related to the abnormality determination of the camera microcomputer 11 according to the fifth embodiment of the present invention, which will be described below.
[0095]
When the main switch 13 is turned on, the camera microcomputer 11 starts the operation of FIG. 15 and first turns off the drive circuit 12y in step # 5001. Next, in step # 5002, the analog switch 51 is turned on, and both ends of the coil 36y are connected to the differential amplifier 52. In the subsequent step # 5003, a built-in timer is started. In the next step # 5004, the natural frequency f of the correction means is applied to the coil 36p. ₀ Is applied to drive the correction means.
[0096]
In the next step # 5005, the process waits until the timer t reaches ta (for example, 0.2 seconds). This is to wait for the resonance of the correction means to stabilize. In the subsequent step # 5006, the camera microcomputer 11 takes in a signal from the window comparator 55. In the next step # 5007, the voltage application to the coil 36p is stopped, and in the subsequent step # 5008, the analog switch 51 is turned off.
[0097]
In step # 5009, it is determined whether or not the signal Va is input from the window comparator 55. If the signal Va is input, the correction means is normal and the process proceeds to the normal camera sequence, but the signal Va is input. If not, it is determined that there is an abnormality in the correction means, and the process proceeds to step # 5010 to drive the display device 16 to notify the user of this fact.
[0098]
In this way, in the case where a plurality of coils are provided to drive the correction means in a plurality of directions, by driving one coil, the electromotive force induced in the other coil due to the interference is measured. Therefore, it is possible to easily determine the abnormality of the correction means without adding new parts.
[0099]
(Sixth embodiment)
In the fifth embodiment, the correction means is the natural frequency f. ₀ The interference drive generated in the other direction is measured by the coil electromotive force. As described above, when the driving frequency is lower than the natural frequency, the interference driving is slight, and the electromotive force of the coil in the direction driven by interference is small.
[0100]
Therefore, in the sixth embodiment of the present invention, the configuration shown in the fifth embodiment is different from that in the fourth embodiment in that the correcting means has a frequency f. ₀ (Natural frequency) and f ₁ Driving is performed at a frequency lower than the natural frequency, and an attempt is made to change to a configuration in which abnormality determination of the correction means is performed based on the relationship of electromotive force in each case.
[0101]
FIG. 16 is a block diagram showing a circuit configuration of a part related to abnormality determination of the correcting means of a compact camera according to the sixth embodiment of the present invention. The same parts as those in FIG. Is omitted.
[0102]
FIG. 16 differs from FIG. 14 in that the output of the differential amplifier 52 is input to the low pass filter 56, and then the output is A / D converted by the A / D converter 57, and the peak voltage in the camera microcomputer 11. Is the point that is required.
[0103]
The low-pass filter 52 has a frequency f ₀ A low-pass circuit that cuts higher frequencies and has a frequency f ₀ , F ₁ It has the function of cutting only noise without affecting the gain.
[0104]
FIG. 17 is a flowchart showing the operation of the part related to the abnormality determination of the camera microcomputer 11 according to the sixth embodiment of the present invention, and the part performing the same operation as in FIG. 15 is given the same step number. A part of the description is omitted.
[0105]
In step # 5011, the frequency f is applied to the coil 36p. ₁ A constant voltage (for example, 0.1 V) (for example, 5 V) is applied to drive the correction means in the 310p direction in FIG. Then, in the next step # 5005, it waits until the drive is stabilized, and then proceeds to step # 5012, where the peak voltage Vyf between the coils 36y is obtained from the A / D conversion value fetched from the A / D converter 57. ₁ Ask and remember.
[0106]
In the next step # 5013, the drive frequency of the coil 36p is set to f. ₀ (For example, 50 Hz) ₀ And in the following steps # 5014 and # 5015, the same operation as in steps # 5005 and # 5012 is performed, and the peak voltage Vyf between the coils 36y is obtained. ₀ Ask and remember. Then, the same operation as in FIG. 15 is performed at step # 5007 and step # 5008, and the process proceeds to step # 5016.
[0107]
In step # 5016, the stored two peak voltages Vyf ₁ And Vyf ₀ Ratio of Vyf ₀ / Vyf ₁ "
[0108]
As mentioned above, the frequency f ₁ When the correction means is driven in the 310p direction, the driving interference in the 310y direction is slight, and the electromotive force peak Vyf generated in the coil 36p. ₁ Is small. However, the frequency f ₀ When the correction means is driven in the 310p direction, a large drive interference occurs in the 310y direction, and Vyf ₀ The value of increases.
[0109]
Therefore, “Vyf ₀ / Vyf ₁ When the value of "" is larger than a certain value a (for example, 2), the correction means is normal, and the normal sequence is started.
[0110]
On the other hand, “Vyf ₀ / Vyf ₁ <A ”is
1) The correction means cannot be driven because the coil 36p is disconnected (or an abnormality has occurred in the permanent magnet 34p).
[0111]
2) Since the coil 36y is disconnected (or an abnormality has occurred in the permanent magnet 34p), no electromotive force is generated.
[0112]
3) One of the components of the correction means is broken and does not move normally.
In such a case, since the correction means is abnormal, the process proceeds from step # 5016 to step # 5010, and the display device 16 is driven to notify the user of this fact.
[0113]
In this way, by performing abnormality determination from the relative relationship between the states of the correction means when driven at two drive frequencies, it does not depend on the shooting environment (temperature, camera posture, lens barrel extension state, etc.) at the time of abnormality determination. Highly reliable abnormality determination is possible.
[0114]
(Correspondence between Invention and Embodiment)
In each of the above embodiments, the correcting means 68 corresponds to the optical axis decentering means and the driven member of the present invention, and the driving circuits 12pa and 12pb, the coils 68pa, 68pb, 68ya and 68yb, the closed magnetic circuits 68pc and 68d, and the permanent magnet. 34p, 34y, coils 36p, 36y correspond to the drive means of the present invention, and the camera microcomputer 11, window comparators 15p, 55, bandpass filters 17p, 53, analog switch 51, and lowpass filter 56 serve as abnormality determination means of the present invention. The resistor 312p corresponds to the constant resistance of the present invention.
[0115]
The above is the correspondence between each configuration of the embodiment and each configuration of the present invention. However, the present invention is not limited to the configuration of the embodiment, and the functions shown in the claims or the embodiment It goes without saying that any configuration may be used as long as the function of the can be achieved.
[0116]
(Modification)
In the present invention, as the optical axis decentering means, an example in which the correction optical system is moved in a plane perpendicular to the optical axis is taken as an example. However, in the light beam changing means such as a variable apex angle prism or in a screen perpendicular to the optical axis. It may be one that moves the imaging surface.
[0117]
Further, although the present invention has been described as being applied to a compact camera, it can also be applied to various forms of cameras such as single-lens reflex cameras, interchangeable lenses, optical devices other than cameras, and other electronic devices. Is.
[0118]
Furthermore, the present invention may be configured by appropriately combining the above embodiments or their techniques.
[0119]
【The invention's effect】
As described above, according to the present invention, the malfunction of the optical axis eccentric means and the drive means for driving the optical axis eccentric means can be prevented. , Power saving and high accuracy Can be detected Anti-vibration device Can be provided.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing main parts of a compact camera according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing an operation of a portion related to abnormality determination of the correcting means of the compact camera according to the first embodiment of the present invention.
FIG. 3 is a configuration diagram showing main parts of a compact camera according to a second embodiment of the present invention.
4 is a diagram for explaining an output signal of the window comparator of FIG. 3; FIG.
FIG. 5 is a front view of correction means of the compact camera according to the first embodiment of the present invention.
6 is a view showing a state viewed from the AA cross section of FIG. 5 and the direction of an arrow 38; FIG.
7 is a perspective view of the correcting means of FIG. 5. FIG.
FIG. 8 is a block diagram showing a configuration of a part related to abnormality determination of a compact camera according to a third embodiment of the present invention.
9 is a diagram showing a change in impedance and a state of resistance voltage when the coil of FIG. 5 is energized. FIG.
FIG. 10 is a flowchart showing an operation of a portion related to abnormality determination of a correcting unit of a compact camera according to a third embodiment of the present invention.
FIG. 11 is a block diagram showing a configuration of a part related to abnormality determination of a compact camera according to a fourth embodiment of the present invention.
FIG. 12 is a flowchart showing an operation of a portion related to abnormality determination of the correcting means of the compact camera according to the fourth embodiment of the present invention.
FIG. 13 is a diagram showing a state of an electromotive voltage generated in the other coil due to interference when one coil is driven at a different frequency in the fifth embodiment of the present invention.
FIG. 14 is a block diagram showing a configuration of a part related to abnormality determination of a compact camera according to a fifth embodiment of the present invention.
FIG. 15 is a flowchart showing an operation of a portion related to abnormality determination of a correcting unit of a compact camera according to a fifth embodiment of the present invention.
FIG. 16 is a block diagram showing a configuration of a part related to abnormality determination of a compact camera according to a sixth embodiment of the present invention.
FIG. 17 is a flowchart showing an operation of a portion related to abnormality determination of a correcting unit of a compact camera according to a sixth embodiment of the present invention.
FIG. 18 is a perspective view showing a configuration of a conventional compact camera having a vibration isolation function.
[Explanation of symbols]
10p vibration detector
11 Camera microcomputer
12pa, 12pb drive circuit
15p, 55 window comparator
16 Display device
17p, 53 band pass filter
34p, 34y permanent magnet
36p, 36y coil
51 Analog switch
52 Differential Amplifier
56 Low-pass filter
68 Correction means
68pa, 68pb coil
68ya, 68yb coil
68pc, 68d closed magnetic circuit
69 Correction optical system
312p resistance

Claims (2)

An optical axis decentering means for decentering the optical axis, a driving means for driving the optical axis decentering means by a magnetic action, and a constant resistance connected in series to a drive coil of the driving means,
When a voltage of the natural frequency of the optical axis eccentric means is applied to a series circuit of the drive coil and the constant resistance, the voltage of the constant resistance is measured, and the voltage of the constant resistance is the optical axis eccentric means. It is determined that there is an abnormality in the operation of at least one of the optical axis decentering means and the driving means when the voltage is not in the voltage range generated in the constant resistance in the resonance state, and there is an abnormality in the voltage range. An apparatus with an anti-vibration function, characterized by having an abnormality determination means for determining that there is no vibration. The operation for determining whether or not there is an abnormality in the operation of at least one of the optical axis decentering means and the driving means is performed prior to the operation of driving the optical axis decentering means and actually activating the anti-vibration function. The device with an anti-vibration function according to claim 1.

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