JP3720404B2 - Vibration correction means locking device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of a shake correction unit locking device including a locking unit that locks a shake correction unit that performs image shake correction due to low-frequency vibration generated in an optical apparatus such as a camera.
[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 even for those who are unskilled in camera operation is very low.
[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 12 Hz as a frequency, but it is fundamental for enabling a photograph without image shake even if such a shake occurs at the time of shutter release. As an idea, it is necessary to detect the vibration of the camera due to the camera shake and displace the correction lens according to the detected value. Accordingly, in order to achieve the ability to take a photograph that does not cause image shake even if camera shake occurs, firstly, it is necessary to accurately detect camera vibration and secondly to correct optical axis changes due to camera shake. Necessary.
[0006]
In principle, this vibration (camera shake) is detected by integrating the vibration sensor that detects angular acceleration, angular velocity, angular displacement, etc. and the output signal of the sensor electrically or mechanically to output angular displacement. This can be done by mounting camera shake detection means on the camera. Then, based on this detection information, a correction optical mechanism that decenters the photographic optical axis is driven to suppress image blur.
[0007]
Here, the outline of the image stabilization system using the vibration detection means will be described with reference to FIG.
[0008]
The example of FIG. 15 is a diagram of a system that suppresses image blur caused by the camera vertical shake 81p and the camera horizontal shake 81y in the direction of the arrow 81 illustrated.
[0009]
In the figure, reference numeral 82 denotes a lens barrel, 83p and 83y denote vibration detection means for detecting camera vertical deflection angular displacement and camera lateral vibration, respectively, and 84p and 84y indicate the respective vibration detection directions. Reference numeral 85 denotes correction means (86p and 86y are coils for applying thrust to the correction means 85, and 87p and 87y are position detection elements for detecting the position of the correction means 85). The correction means 85 is provided with a position control loop which will be described later. Therefore, it is driven with the outputs of the vibration detecting means 83p and 83y as target values to ensure stability on the image plane 88.
[0010]
Next, FIG. 16 is an exploded perspective view showing the structure of the correction means suitably used for such purposes.
[0011]
A bearing 73y is press-fitted into the support frame 72 in which the lens 71 is crimped. A support shaft 74y is supported by the bearing 73y so as to be slidable in the axial direction. The recess 74 ya of the support shaft 74 y is fitted into the claw 75 a of the support arm 75. A bearing 73p is also press-fitted into the support arm 75, and the support shaft 74p is supported so as to be slidable in the axial direction.
[0012]
In FIG. 16, a back view of the support arm 75 is also shown, and a partial front view for clearly showing the claw 75a is also shown.
[0013]
Light projecting elements 76p and 76y such as IRED are bonded to the projector mounting holes 72pa and 72ya of the support frame 72, and terminals thereof are soldered to lids 77p and 77y (adhered to the support frame 72) that also serve as a connection board. The Further, the support frame 72 is provided with slits 72pb and 72yb, and the light projections of the light projecting elements (IRED: infrared light emitting diodes) 76p and 76y pass through the slits 72pb and 72yb and enter PSDs 78p and 78y described later. . Coils 79p and 79y are also bonded to the support frame 72, and the terminals are soldered to the lids 77p and 77y.
[0014]
The lens barrel 710 is provided with support balls 711 (three places), and has a claw portion 710a into which the recess 74pa of the support shaft 74p is inserted.
[0015]
York 712p₁ 712p₂ 712p_Three , The magnet 713p is overlapped and bonded, and similarly the yoke 712y₁ 712y₂ 712y_Three The magnet 713y is also overlapped and bonded. In addition, the polarity of a magnet becomes arrangement | positioning of arrow 713pa and 713ya.
[0016]
York 712p₂ 712y₂ Are screwed into the recesses 710pb and 710yb of the lens barrel 710.
[0017]
Position detection elements 78p and 78y such as PSD are adhered to sensor seats 714p and 714y (714y is not shown), and sensor masks 715p and 715y are covered, and position detection elements (PSD: semiconductor position detector) 78p are placed on the flexible substrate 716. The 78y terminal is soldered. The convex portions 714 pa and 714 ya (714 ya not shown) of the sensor seats 714 p and 714 y are fitted into the mounting holes 710 pc and 710 yc of the lens barrel 710, and the flexible substrate 716 is screwed to the lens barrel 710 by the flexible substrate stay 717. The ears 716pa and 716ya of the flexible substrate 716 pass through the holes 710pd and 710yd of the lens barrel 710, respectively, and the yoke 712p.₁ 712y₁ The coil terminals and the light projecting element terminals on the lids 77p and 77y are connected to the ear portions 716pa and 716ya of the flexible substrate 716 and the polyurethane copper wires (three wires), respectively. .
[0018]
A plunger 719 is screwed to the mechanical lock chassis 718, and the plunger 719 is fitted into the mechanical lock arm 721 charged with the spring 720, and is rotatably screwed to the mechanical lock chassis 718 by the shaft screw 722.
[0019]
The mechanical lock chassis 718 is screwed to the lens barrel 710, and the terminals of the plunge 719 are soldered to the land portions 716 b of the flexible substrate 716.
[0020]
A spherical adjustment screw 723 (3 locations) is provided on the yoke 712p.₁ The mechanical lock chassis 718 is screwed through, and the sliding surface (shaded portion 72c) of the support frame 72 is sandwiched between the adjusting screw 723 and the support ball 711. The adjustment screw 723 is screwed and adjusted so as to face the sliding surface with a slight clearance.
[0021]
A cover 724 is bonded to the lens barrel 710 and covers the correction means described above.
[0022]
FIG. 17 is a diagram for explaining the drive control system of the correcting means of FIG.
[0023]
When the outputs of the position detection elements 78p and 78y are amplified by the amplification circuits 727p and 727y and input to the coils 79p and 79y, the support frame 72 is driven and the outputs of the position detection elements 78p and 78y change. Here, when the driving direction (polarity) of the coils 79p and 79y is set to a direction in which the output of the position detection elements 78p and 78y becomes small (negative feedback), the output of the position detection elements 78p and 78y is generated by the driving force of the coils 79p and 79y. The support frame 72 is stabilized at a position where it becomes almost zero. The addition circuits 731p and 731y are circuits for adding the outputs from the position detection elements 78p and 78y and external command signals 730p and 730y, and the compensation circuits 728p and 728y are circuits for further stabilizing the control system and driving. The circuits 729p and 729y are circuits that compensate for the current applied to the coils 79p and 79y.
[0024]
When the command signals 730p and 730y are externally supplied to the system of FIG. 17 via the adder circuits 731p and 731y, the support frame 72 is driven very faithfully to the command signals 730p and 730y.
[0025]
The method of controlling the coil by negatively feeding back the position detection output as in the control system of FIG. 17 is called a position control method. When the amount of camera shake is given as the command signals 730p and 730y, the support frame 72 is proportional to the amount of camera shake. Driven.
[0026]
FIG. 18 is a circuit diagram showing details of the drive control system of the correcting means shown in FIG. 17, and only the pitch direction 725p will be described here (because the yaw direction 726y is the same).
[0027]
The current-voltage conversion amplifiers 732pa and 732pb generate a photocurrent 78i generated in the position detection element 78p (comprising resistors R1 and R2) by the light projecting element 76p.₁ 78i₂ The differential amplifier 733p obtains a difference between the current-voltage conversion amplifiers 732pa and 732pb (an output proportional to the position of the support frame 72 in the pitch direction 725p). The current-voltage conversion amplifiers 732pa and 732pb, the differential amplifier 733pc, and the resistors R3 to R10 constitute the amplifier 727p shown in FIG.
[0028]
The command amplifier 734pa adds a command signal 730p input from the outside to the difference signal of the differential amplifier 733p, and the resistors R11 to R14 constitute the adder circuit 731p of FIG.
[0029]
The resistors 738p and 739p and the capacitor 740p are known phase advance circuits, which correspond to the compensation circuit 728p in FIG.
[0030]
The output of the adder circuit 731p is input to the drive amplifier 735p via the compensation circuit 728p, where a drive signal for the pitch coil 79p is generated and the correction means is displaced. The drive amplifier 735p, the resistor 737p, and the transistors 736pa and 736pb constitute the drive circuit 729p shown in FIG.
[0031]
The addition amplifier 741p calculates the sum of the outputs of the current-voltage conversion amplifiers 732pa and 732pb (the total amount of light received by the position detection element 78p), and the drive amplifier 742p receiving this signal drives the light projecting element 76p accordingly. As described above, the adder amplifier 741p, the drive amplifier 742p, the resistors R18 to R24, and the capacitor C1 constitute a drive circuit for the light projecting element 76p (not shown in FIG. 17).
[0032]
The light projection amount of the light projecting element 76p changes extremely instability with respect to temperature and the like, and the position sensitivity of the differential amplifier 733p changes accordingly. However, as described above, the above driving is performed so that the total amount of received light is constant. If the light projecting element 76p is controlled by a circuit, the change in position sensitivity is reduced.
[0033]
Here, a locking device for locking the support frame 72 shown in FIGS. 16 and 17 will be described.
[0034]
The locking device is constituted by the mechanical lock chassis 718, the spring 720, the mechanical lock arm 721, the shaft screw 722 (which constitutes the locking means) and the plunger 719 (which constitutes the locking drive means) described in FIG. FIG. 19A shows the locking device viewed from the direction of the arrow 718a in FIG. 16, and FIG. 19B shows a sectional view of the plunger 719.
[0035]
In FIG. 19B, the plunger 719 includes a slider 719a, a stator 719b, a coil 719c provided on the stator 719b, and a permanent magnet 719d. As shown in FIG. 19A, the slider 719a is hooked in a hole 721b of a mechanical lock arm 721 that is rotatably supported by a shaft 722. The mechanical lock arm 721 is rotated in the direction of an arrow 720a by a spring 720. It is energized. Therefore, the slider 719a always receives the force Fout that is pulled out from the stator 719b. However, since the slider 719a is in contact with the permanent magnet 719d, its attractive force is large and is not moved by the force of the spring 720 (Fmg> Fout: Fmg is the attractive force of the permanent magnet). In this state, the protrusion 721a at the tip of the mechanical lock arm 721 is fitted in the hole 72d of the support frame 72, and the support frame 72 is locked.
[0036]
Next, when a current is passed through the coil 719c in a desired direction, the flow of magnetic flux in the magnetic circuit composed of the permanent magnet 719d, the slider 719a, and the stator 719b changes, and the attractive force of the slider 719a and the permanent magnet 719d is weakened. . Then, the mechanical lock arm 721 is rotated in the direction of the arrow 720a by the force of the spring 720, and the protrusion 721a is separated from the hole 72d of the support frame 72 to be unlocked (Fout> Fmg−Fi Fi is a current repulsive force). At this time, the slider 719a is simultaneously pulled out of the stator 719b, and a gap δ is generated between the slider 719a and the permanent magnet 719d.
[0037]
As is well known, the attractive force is inversely proportional to the square of the distance between the permanent magnet 719d and the opposing object, so that the attractive force becomes extremely small due to the occurrence of the gap δ. Therefore, even when the coil 719c is de-energized, the support frame 72 can be kept unlocked by the biasing force of the spring 720.
[0038]
Next, when a current is passed through the coil 719c in the reverse direction, the resultant force of the absorption force of the slider 719a and the attractive force of the permanent magnet 719d due to this current becomes larger than the force of the spring 720, and the slider 719a is drawn into the stator 719b ( Fmg + Fi> Fout)
Once the slider 719a starts to be pulled into the stator 719b, the absorbing power of the permanent magnet 719d increases at an accelerated rate due to the gap δ decreasing, the slider 719a abuts against the permanent magnet 719d, and the protrusion 721a is supported by the support frame. 72 enters the hole 72d of the 72, and the support frame 72 is locked again.
[0039]
As described above, a current is allowed to flow through the plunger 719 only at the time of locking and unlocking, so that each state is maintained, and a small and power-saving locking device is realized.
[0040]
FIG. 20 is a block diagram showing an outline of the image stabilization system.
[0041]
In FIG. 20, reference numeral 91 denotes the vibration detection means 83p and 83y of FIG. 15, which is a vibration detection sensor for detecting angular velocities such as a vibration gyro, and a sensor for obtaining an angular displacement by integrating the DC component of the output of the vibration detection sensor after cutting. It is comprised from an output calculating means.
[0042]
The angular displacement signal from the vibration detection unit 91 is input to the target value setting unit 92. The target value setting means 92 is composed of a variable differential amplifier 92a and a sample hold circuit 92b. Since the sample hold circuit 92b is always sampling, both signals inputted to the variable differential amplifier 92a are always equal. Its output is zero. However, when the sample-and-hold circuit 92b is in a hold state by an output from the delay means 93 described later, the variable differential amplifier 92a starts to output continuously at that point in time.
[0043]
The amplification factor of the variable differential amplifier 92a is variable by the output of the image stabilization sensitivity setting means 94. This is because the target value signal of the target value setting means 92 is a target value (command signal) for causing the correction means to follow, but the image plane correction amount (anti-shake sensitivity) with respect to the drive amount of the correction means is zoom, This is to compensate for the change in the anti-vibration sensitivity because the optical characteristic changes based on the focus change such as the focus. Therefore, the image stabilization sensitivity setting unit 94 receives the zoom focal length information from the zoom information output unit 95 and the focus focal length information based on the distance measurement information from the exposure preparation unit 96, and determines the image stabilization sensitivity based on the information. Anti-vibration sensitivity information set in advance based on the calculation or the information is extracted, and the amplification factor of the variable differential amplifier 92a of the target value setting means 92 is changed.
[0044]
The correction drive means 97 is the drive control circuit shown in FIG. 18, and the target values from the target value setting means 92 are input as command signals 730p and 730y.
[0045]
The correction starting means 98 is a switch for controlling the connection between the drive circuits 729p and 729y of FIG. 17 and the coils 79p and 79y. Normally, the switch 98a is connected to the terminal 98c so that each of the coils 79p and 79y is connected. Both ends are short-circuited, and when the signal of the logical product means 99 is input, the switch 98a is connected to the terminal 98b, and the correction means 910 is in a controlled state (although no shake correction is performed yet, power is supplied to the coils 79p and 79y. Then, the correction means 910 is stabilized at a position where the signals of the position detection elements 78p and 78y become substantially zero). At the same time, the output signal of the logical product means 99 is also input to the locking means 914, whereby the locking means unlocks the correcting means 910.
[0046]
The correction means 910 inputs the position signals of the position detection elements 78p and 78y to the correction drive means 97, and performs position control as described above.
[0047]
When both the release half-press SW1 signal from the release means 911 and the output signal from the image stabilization switching means 912 are input to the logical product means 99, the AND gate 99a, which is a component, outputs the signal.
[0048]
That is, when the photographer operates the image stabilization switch of the image stabilization switching means 912 and performs the release half-press with the release means 911, the correction means 910 is released from the locked state and enters the control state.
[0049]
The SW1 signal from the release unit 911 is input to the exposure preparation unit 96 to perform photometry, distance measurement, and lens focusing drive, and output focus focal length information to the image stabilization sensitivity setting unit 94 as described above.
[0050]
The delay means 93 receives the output signal of the logical product means 99 and outputs it after one second, for example, and outputs the target value signal from the target value setting means 92 as described above.
[0051]
Although not shown, the vibration detecting unit 91 starts to be activated in synchronization with the SW1 signal of the release unit 911. As described above, the sensor output calculation including a large time constant circuit such as an integrator requires a certain amount of time from the start to the stabilization of the output.
[0052]
The delay means 93 plays a role of outputting a target value signal to the correction means 910 after waiting until the output of the vibration detection means 91 becomes stable, and starts the image stabilization after the output of the vibration detection means 91 becomes stable. ing.
[0053]
The exposure means 913 performs mirror up in response to the release push-off SW2 signal input from the release means 911, performs exposure by opening and closing the shutter at the shutter speed determined based on the photometric value of the exposure preparation means 96, and takes a picture with the mirror down. Exit.
[0054]
When the photographer releases the release means 911 and turns off the SW1 signal after the photographing is finished, the AND means 99 stops the output, the sample hold circuit 92b of the target value setting means 92 enters the sampling state, and the variable differential The output of the amplifier 92a becomes zero. Accordingly, the correction unit 910 returns to the control state where the correction drive is stopped.
[0055]
Since the output of the logical product means 99 is turned off, the locking device 914 locks the correction means 910, and then the switch 98a of the correction starting means 98 is connected to the terminal 98c, and the correction means 910 is not controlled. .
[0056]
The vibration detecting unit 91 continues to operate for a certain time (for example, 5 seconds) after the operation of the release unit 911 is stopped by a timer (not shown), and then stops. This is because it is complicated for the photographer to continue the release operation after stopping the release operation, so that it is possible to prevent the vibration detecting means 91 from being activated every time and to shorten the waiting time until the output is stabilized. Therefore, when the vibration detecting means 91 has already been activated, the vibration detecting means 91 sends an activated signal to the delay means 93 to shorten the delay time.
[0057]
[Problems to be solved by the invention]
In the anti-vibration system described above, a locking device (a mechanical lock chassis 718, a plunger 719, a spring 720, a mechanical lock arm 721, a shaft screw 722 in FIG. 16) for locking a correction means (hereinafter referred to as a shake correction means). Had the following problems.
[0058]
First, when power is interrupted during image stabilization, that is, when the battery of an optical device such as a camera having the image stabilization system is removed during image stabilization or when it is depleted, the image stabilization means is locked. It is impossible to. This is because the conventional locking device has the characteristic of maintaining the current state (self-holding force), and therefore power is required to shift from the unlocked state to the locked state. This is because when the power is cut off in the stop release state (during vibration isolation), the lock state cannot be established.
[0059]
In order to solve this problem, for example, it has been proposed to have a capacitor for power backup as in Japanese Patent Publication No. 3-24116, and to perform locking driving with this capacitor when the power is cut off. This is not a countermeasure when the battery is not charged, and the capacitor for power backup is considerably unsuitable as a consumer device because of its large size.
[0060]
In addition, as shown in, for example, Japanese Patent Laid-Open No. 62-18874, an example of using a motor instead of a plunger for driving a locking device has been proposed. However, when a motor is used, a transmission gear is always required. Since the entire locking means drive section has self-holding force due to friction between gears and cogging of the motor itself, it is necessary to energize the motor for locking, and also locking cannot be performed when power is cut off .
[0061]
Therefore, since the shake correction means is in the unlocked state after the power interruption occurs in this way, the shake correction means swings when carrying this optical device, and not only abnormal noise is generated, but also It can also cause damage.
[0062]
Second, when the conventional locking device is driven, especially when the locking drive is performed, the bottom of the slider 719a of the plunger 719 collides with the permanent magnet 719d (see FIG. 19) and generates a loud sound, which is uncomfortable. .
[0063]
In this way, a drive unit having a self-holding force often performs a sudden deceleration when it reaches its stable point, so that a noise is generated and the locking speed can be controlled due to its self-holding force. It is difficult to suppress the generation of sound by electrical control.
[0064]
Thirdly, let us consider a case where the lock is released due to some disturbance or vibration in the state where the shake correction means is locked (when the protrusion 721a in FIG. 16 is released from the hole 72d of the shake correction means).
[0065]
At this time, if the optical apparatus having the image stabilization system is in an unused state, naturally, no power is supplied, and therefore there is a problem that the image stabilization means cannot be brought into the locked state.
[0066]
(Object of the invention) The object of the present invention is toWhile achieving power saving when holding the shake correction means in the unlocked state,Stabilize the shake correction unit with the locking unit in any state such as when the power is cut off.MakeAnother object of the present invention is to provide a shake correction means locking device that can be used.
[0072]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a locking means for locking a shake correction means for correcting image shake, an elastic member for biasing the locking means in a locking direction, a coil, and the A magnetic field generating means arranged opposite to the coil, and when the electric power is applied to the coil, the locking means is driven to change the shake correcting means from the locked state to the unlocked state. Locking drive means that does not have a self-holding force when driven,It is composed of an electromagnet provided in the fixed part and an iron piece provided in the locking means,In the state of unlocking of the shake correcting means by the locking drive meansThe electromagnet and the iron pieceAnd holding means for maintaining the released state while the contacted state is maintained by the supply of electric power, and the coil of the locking drive means is held when the released state is held by the holding unit. Is a shake correction means locking device that stops power supply or supplies power smaller than that during driving to the unlocked state.
[0078]
【Example】
Hereinafter, the present invention will be described in detail based on the illustrated embodiments.First, the first technical example which is the premise of the present invention will be described..
[0079]
FIG. 1 shows a first embodiment of the present invention.Prerequisite technology examplesIt is a disassembled perspective view which shows the shake correction means locking device which concerns on this, and the part which has the same function as FIG. 16 is attached | subjected the same code | symbol.
[0080]
The support frame 72 is sandwiched between a support ball (ball) 711 and two lens barrels 710 and 710 ′, and the lens71A holding frame 72a [see FIG. 1 (b)] holding the screw is screwed. The shaft 74 has an L shape, and the coil 79 (79p, 79y) is a flat coil. A mounting portion of a position detection element (PSD: semiconductor position detector) 78 (78p, 78y) is a hard substrate 716 'and is thermocompression bonded to the flexible substrate 716. However, the basic configuration is not different from the conventional example of FIG.
[0081]
In FIG. 1, a mechanical lock ring 11 constitutes a locking means, a mechanical lock coil 12, a permanent magnet 13 and a yoke 14 facing the mechanical lock coil 12 constitute a locking drive means, and a mechanical lock spring 15 constitutes an elastic means. . In addition, the lens 71, the holding frame 72a, and the protrusion 16 constitute shake correction means.
[0082]
The mechanical lock ring 11 is supported on the back surface of the lens barrel 710 so as to be rotatable about the optical axis. By rotating, the cam portions 11a (four locations) forming the locking portions of the locking means are provided on the back surface of the support frame 72. The projections 16 (provided at four positions on the holding frame 72a) are locked. This will be described with reference to FIG.
[0083]
FIG. 2A shows the unlocking state of the shake correcting means. In this state, the protrusion 16 is separated from the cam portion 11a, and the shake correction means can freely move within this range. However, when the mechanical lock ring 11 rotates in the direction of the arrow 17 as shown in FIG. 2B, the protrusion 16 comes into contact with the inner diameter portion of the mechanical lock ring 11, and the shake correction means is locked.
[0084]
Here, the rotation in the direction of the arrow 17 is performed by the elastic force of the mechanical lock spring 15. The mechanical lock spring 15 is pivotally supported by a pin 15a of a fixing portion (not shown) (for example, on the lens barrel 710), one end of which similarly contacts a stopper 15b of the fixing portion (not shown), and the other end is a mechanical lock ring 11. It is in contact with the upper pin 11b. In the locked state as shown in FIGS. 1A and 2B, the pin 11b on the mechanical lock ring 11 abuts against a charge member 15e of a fixed portion (not shown) and is prevented from rotating. The tangential force for rotating the mechanical lock ring 11 is 15d with respect to the spring force 15d 'at this time (see FIG. 2B).
[0085]
Next, when the mechanical lock ring 11 is rotated by the mechanical lock coil 12 in the opposite direction to the arrow 17 against the spring force of the mechanical lock spring 15, and the shake correction means is unlocked, the mechanical lock spring 15 has a spring force 15c '. On the other hand, the tangential force of the mechanical lock ring 11 is 15c [see FIG. 2 (a)]. That is, the spring force of the mechanical lock spring 15 is smaller in the unlocked state than in the locked state. Normally, when the spring moves against the spring force, the spring force increases, but in the present embodiment, the spring force is reduced.
[0086]
The reason is that when the vibration isolating system is used, the mechanical lock ring 11 is in the state shown in FIG. 2 (a) and the vibration correcting means is in the unlocked state. is there. As shown in FIG. 1 (a), when the locking drive means is composed only of a coil and a permanent magnet (including a yoke), it does not have a self-holding function. This is because the mechanical lock spring 15 has a large spring force, and it is necessary to increase the electric power to the mechanical lock coil 12 for releasing and retaining the latch. When the camera is equipped with the image stabilization system equipped with the shake correction means locking device of the present embodiment, the image stabilization is started by half-pressing the release button (SW1) as described in FIG. In this case, the half-pressed time is extremely longer than the actual exposure time, and it is not preferable that the mechanical lock coil 12 requires a large amount of power in order to maintain the unlocking during this time. Therefore, the structure is such that the spring force of the mechanical lock spring 15 is reduced when the latch is released.
[0087]
Further, when the shake correction means is locked, the spring force 15d 'of the mechanical lock spring 15 is increased as shown in FIG. 2B, and once locked, the locked state is held very stably.
[0088]
The cam portion 11a is a cam surface (tapered surface) along the rotation direction of the mechanical lock ring 11 (the direction of the arrow 17), so even if the support frame 72 is not stable at the center of the optical axis, the mechanical lock ring. When 11 rotates in the direction of arrow 17, the cam surface pushes up the protrusion 16 to move the shake correction means to a desired position and be locked.
[0089]
As described above, since the mechanical lock coil 12 itself does not have a self-holding capability, when the power is cut off, the mechanical lock ring 11 rotates in the direction of the arrow 17 and the contact surface of the protrusion 16 of the support frame 72 is a cam. By the surface (the shape of the cam portion 11a formed on the mechanical lock ring 11), ““It is possible to lock the shake correction means from any state” and “to obtain a locking drive means that is compact and does not need to include a power backup means”. .
[0090]
The spring force of the mechanical lock spring 15 is large as indicated by 15d in FIG. Therefore, the driving force of the mechanical lock coil 12 requires a large force when rotating the mechanical lock ring 11 in the direction opposite to the arrow 17.
[0091]
FIG. 3 is a timing chart showing the state of power supply to the mechanical lock coil 12. The vertical axis represents power and the horizontal axis represents time.
[0092]
In FIG. 3A, when unlocking of the shake correction means is performed (that is, at the start of vibration isolation), a large electric power is applied to the mechanical lock coil 12, and the mechanical lock ring 11 is moved in the direction opposite to the arrow 17 with a large force. To drive. This time is about 20 msec, for example, and the total power is not large.
[0093]
When the lock is released, the spring force of the mechanical lock spring 15 is reduced. Therefore, the driving force of the mechanical lock coil 12 against the spring force is small, and during this time (for example, the photographer takes about 10 seconds The power is reduced when aiming.
[0094]
As a method for reducing the electric power, as shown in FIG. 4, the mechanical lock coil 12 is energized by PWM (pulse width modulation) by a control means (not shown), thereby reducing the power consumption of the drive circuit itself of the mechanical lock coil 12. I am trying. In FIG. 4, the voltage applied to the mechanical lock coil 12 is the same in both (a) and (b), but the applied time is set to a pulse of about 20 KHz, for example, and the pulse width is changed as shown in (a). If the pulse width is wide, the power becomes large, and if the pulse width is narrow as shown in (b), the power becomes small.
[0095]
As described above, the power is increased only at the time of unlocking drive, and the power is decreased when maintaining the unlocked state., “A power-saving locking drive means ”can be realized.
[0096]
Next, as shown in FIG. 3A, the mechanical lock coil 12 is again used when the optical apparatus on which the apparatus is mounted is used (exposure for a silver halide camera, exposure for a video camera). Increase the power to. This is because when the stability of unlocking is most required in this way, the unlocking is maintained even when a disturbance occurs.“It is possible to reliably hold the unlocked state.
[0097]
Next, when stopping vibration isolation, the mechanical lock ring 11 is rotated in the direction of the arrow 17 to lock the shake correction means. The rotation of the mechanical lock ring 11 in the direction of the arrow 17 is caused by the spring force of the mechanical lock spring 15. In addition, as shown in FIG. 3A, the mechanical lock ring 11 is forcibly driven by applying an electric power (negative electric power) in the opposite direction to the mechanical lock coil 12. Thereby, reliable locking drive is possible. Of course, when the power is shut off, the driving in this locking direction cannot be performed, and the locking is performed only by the spring force of the mechanical lock spring 15. ) The merit of locking is born.
[0098]
FIG. 3B shows an example in which the magnitude and direction of electric power to the mechanical lock coil 12 when the vibration isolation is stopped are different from those in FIG.
[0099]
That is, in FIG. 3B, a weak driving force is applied to the mechanical lock coil 12 in a direction against the spring force of the mechanical lock spring 15. Therefore, the angular velocity when the mechanical lock ring 11 is rotated by the spring force of the mechanical lock spring 15 can be suppressed, and the sound when the pin 11b comes into contact with the stopper member 15e when the locking is completed can be reduced. This, “"Low driving noise when locking (silence)".
[0100]
Even in this configuration, this function does not work when the power is cut off, so the drive sound cannot be lowered. However, the state of power cut is rare, and the drive sound is lowered at the normal time, so there is no problem.
[0101]
In order to reduce the angular velocity of the mechanical lock ring 11, not only the method shown in FIG. 3 (b) but also the mechanical damping coil 12 is short-circuited to give speed damping as shown in FIG. 3 (c). The angular velocity of the mechanical lock ring 11 may be reduced. In this case, it is possible to instantaneously short-circuit the mechanical lock coil 12 even when the power is cut off, and there is an advantage that the driving sound can be reduced even when the electric power is cut off.
[0102]
In general, in the initial stage of driving a member, a driving force is required until the static friction between the members is overcome and the members start to move. Once the members start to move, dynamic friction occurs between the members. Since it is small, the driving force is small.
[0103]
Focus on this, MeThe carlock ring 11 is also given a driving force (electric power required at the time of unlocking in FIG. 3) that overcomes static friction only in the initial stage of driving, and the driving force can be reduced after the mechanical lock ring 11 starts moving (that is, Therefore, power can be saved.
[0104]
In FIG. 5, (a) shows that the same electric power as in FIG. 3 is applied to the mechanical lock coil 12 at the initial stage of unlocking to start the operation of the mechanical lock ring 11, and the electric power is lowered in the later stage of unlocking. An example of power saving is shown.
[0105]
In addition, the switching of the power magnitude is, ClerkAlthough it is performed in the time from the beginning of the lock release (for example, 10 msec from the start of the lock release, the driving power is large), the operation itself of the mechanical lock ring 11 is detected by a switch or a position sensor. You may do it.
[0106]
Further, in FIG. 5 (a), when the unlocking holding is completed and the mechanical lock ring 11 is driven in the locking direction (the direction of the arrow 17), the mechanical lock coil 12 is also connected to the mechanical lock coil 12 at the initial stage of driving. A similar amount of power is applied in the reverse direction, but the power is then reduced.
[0107]
In FIG. 5B, at the initial stage of the locking drive, the brake in the locking direction in FIG. 3B (energization of the mechanical lock coil 12) is weakened (the power of the mechanical lock coil 12 is weakened), and the mechanical lock spring 15 is turned off. A brake that increases the spring force to act on the mechanical lock ring 11, drives the mechanical lock ring 11 to overcome the static friction in the locking direction, and then energizes the mechanical lock coil 12 to weaken the spring force of the mechanical lock spring 15. Power is given and it aims at silence.
[0108]
By adopting such a configuration, it is possible to achieve further power saving as compared with the method of FIGS. 3A and 3B, and further promote the above-described “power saving of the locking drive means”. It has become.
[0109]
As for the driving in the locking direction of the mechanical lock ring 11, as shown in FIG. 5C, the locking direction driving force (at this time, the mechanical locking coil 12) first overcomes the static friction by energizing the mechanical locking coil 12 in the reverse direction. When the mechanical lock ring 11 starts to move in the locking direction, the forward power is applied to the mechanical lock coil 12 as shown in FIG. The brake force in the locking direction may be applied to reduce the noise, and the mechanical lock coil 12 may be short-circuited during this time.
[0110]
Also, MeThe cullock coil 12 is directly attached to the mechanical lock ring 11 (locking means).AlsoIt is int. If the driving force of the mechanical lock coil 12 is transmitted to the locking portion by drive transmission means such as gears, cams, links, etc., a self-holding force will be obtained as the locking means due to friction between them. For this reason, although the mechanical lock coil 12 is not energized even when the power is shut off, if the friction of the drive transmission means is larger than the spring force of the mechanical lock spring 15, the locking operation cannot be performed.
[0111]
Therefore, MeA direct drive structure in which the cullock coil 12 is directly attached to the mechanical lock ring 11 is employed. Of course, if the friction of the drive transmission means is negligible with respect to the spring force of the mechanical lock spring 15, it is not necessary to have a direct drive structure. For example, the drive transmission means is not a gear, a mechanical lock coil for driving, A coreless motor may be used (a coreless motor does not have a self-holding force). The important thing here is the aboveof"In order to achieve the fact that the shake correction means can be locked from any state, the driving means having no self-holding force such as a coil or a coreless motor can be used for driving the locking means. Yes, drive means having self-holding force such as a DC cored motor, a step motor, and a solenoid (plunger) are not used.
[0112]
(SecondPrerequisite technology examplesFIG. 6 shows the present invention.PremiseSecondTechnical examples2 is an exploded perspective view of the shake correction means locking device according to FIG. 1, and the same parts as those in FIG.
[0113]
The difference from FIG. 1 is that a protrusion 11c is provided on the mechanical lock ring 11, and a pin 18a extending from the drive transmission disk 18 is in contact with the protrusion 11c. A spring 19 (elastic means) is charged and hung between the pin 18a and a pin 19a extending from a fixed portion (not shown) (for example, on the lens barrel 710). The shaft 18b of the drive transmission disk 18 is also fitted in a fixed portion (not shown) (for example, on the lens barrel 710) so that it can rotate smoothly.
[0114]
FIG. 7A is a diagram showing the state of the mechanical lock ring 11 when the lock is released. At this time, the spring force between the pin 19a and the pin 18a is 19b '. Since the torque to rotate in the direction (the tangential force 19b applied to the drive transmission disk 18) is small, the force to turn the mechanical lock ring 11 in the direction of the arrow 17 by this pin 19 is small. Therefore, the electric power given to the mechanical lock coil 12 'in order to keep the unlocking can be small. Further, since the tangential force increases as shown in 19c (see FIG. 7A) at the time of locking, the locked state can be stably maintained. For that reason, “It is possible to realize “to perform unlocking and holding with power saving”.
[0115]
Further, the arrangement of the mechanical lock coil 12 'as shown in FIG.
[0116]
The shake correction means also has permanent magnets 713p and 713y for driving, but the arrangement of the permanent magnets 13 for driving the mechanical lock coil 12 is arranged parallel to the permanent magnets 713p and 713y in the optical axis direction [ 6 (a) and 7 (b)], the magnetic fluxes of the permanent magnets 713 and 13 'have the same magnetic path 13a', and the magnetic flux between the gaps where the coil 79 and the mechanical lock coil 12 'are arranged. The density can be increased. Therefore, a large mechanical lock ring driving force can be obtained even with a small electric power, and the “power-saving locking driving means” similar to the above can be obtained.
[0117]
Also, the permanent magnet 13 to be arranged has the same shape as the permanent magnets 713p and 713y, or a shape obtained by cutting this dimension, and uses the same permanent magnet for driving the shake correction means, and the type of the parts. By reducing, cost reduction and assembly management can be simplified.
[0118]
As shown in FIG. 7C, when the mechanical lock coil 12 is arranged in the magnetic path for driving the shake correcting means., “A low-cost locking drive means ”can be obtained.
[0119]
(ThirdPrerequisite technology examplesFIG. 8 shows the present invention.PremiseThirdTechnical examples2 is an exploded perspective view of the shake correction means locking device according to FIG. 1, and the same parts as those in FIG.
[0120]
The firstPrerequisite technology examplesThe difference from FIG. 1 is that the locking drive means has a moving magnet configuration.
[0121]
In FIG. 8, the mechanical lock ring 11 is driven by the relationship between the mechanical lock coil 12 fixed to a fixing portion (not shown) (for example, on the lens barrel 710) and the permanent magnet 13 fixed to the mechanical lock ring 11. Since the mechanical lock coil 12 is arranged on the fixed side in this way, the processing of the lead wire becomes simple (when the coil is arranged on the driving side, the lead wire needs to be processed so as not to disturb the driving). Assemblability is improved, and the problem of disconnection of the lead wire due to driving is eliminated, so durability is also improved.
[0122]
(ExampleFIG. 9 shows the present invention.oneIt is a disassembled perspective view of the shake correction means locking device concerning an example, and the same portion as Drawing 1 is attached with the same numerals.
[0123]
The firstPrerequisite technology examplesThe difference from FIG. 1 is that an electromagnet 21 composed of a yoke 21a and an attracting coil 21b is provided on a fixed portion (for example, on the lens barrel 710), and an iron piece 22 is provided on the mechanical lock ring 11. When the lock is released, they are brought into contact with each other, and the lock release is held by the attraction force.The other configurations and effects are the same as those of the first premise technology example, and the description thereof is omitted.The
[0124]
Since the electromagnet 21 once attracts the iron piece 22 and generates a strong attracting force even with a small amount of electric power, the mechanical lock ring 11 is driven by the mechanical lock coil 12 until the iron piece 22 is brought into contact with and attracted to the electromagnet 21, and the latch is released. The purpose of this embodiment is to make the electromagnet 21 perform with a small amount of power.
[0125]
FIG. 10A shows a timing chart at the time of the operation. At the time of locking release driving, electric power 31 is applied to the mechanical lock coil 12 to drive the mechanical lock ring 11. At this time, the holding power 32 starts to flow also to the attracting coil 21b of the electromagnet 21. Then, when the iron piece 22 is attracted to the electromagnet 21, the supply of the locking drive power 31 is stopped.
[0126]
In this embodiment, the power is stopped for a certain time from the start of unlocking, but the switch (for example, the iron piece 22 and the electromagnet 21 abut that the iron piece 22 is attracted by the electromagnet 21 and is electrically connected to each other). Detection) or a position sensor, and the supply of the unlocking power may be stopped.
[0127]
As described above, since the electromagnet 21 exhibits a strong attracting force even with a small amount of electric power, it is possible to perform “unlocking and holding with low power consumption”, which is one object of the present invention, by adopting such a configuration. It becomes.
[0128]
In FIG. 10A, the holding power 32 is increased at the time of exposure. For this reason, the iron piece 22 is held with a stronger attracting force. Because of this, ““Reliably release and hold”.
[0129]
At the time of locking, the energization of the adsorption coil 21b is cut off, and the mechanical lock ring 11 is driven in the locking direction by the spring force of the mechanical lock spring 15. For this reason, since the energization to the attracting coil 21b is cut off even when the power is cut off, the shake correction means is locked, and the purpose of “the shake correction means can be locked from any state” can be achieved. It becomes possible.
[0130]
Further, as shown in FIG. 10 (b), the latch release can be maintained by applying a small electric power 31a to the mechanical lock coil 12 even when the latch is held. . This is because, generally, when the iron piece 22 moves away from the electromagnet 21, its attractive force weakens in an accelerated manner (the attractive force is inversely proportional to the square of the distance between the electromagnet 21 and the iron piece 22). However, since the driving force of the mechanical lock coil 12 is almost constant regardless of the rotational position of the mechanical lock ring 11, the iron piece 22 is prevented from being detached from the electromagnet 21 by the disturbance. I can do it. In addition, by increasing the power supplied to the mechanical lock coil 12 as in 31b even during exposure, "to ensure that the shake correction means is unlocked"aboutCan be achieved.
[0131]
(First reference technology exampleFIG. 11 shows the present invention.First reference technology example related toFIG. 10 is an exploded perspective view of the shake correction means locking device according to FIG.
[0132]
UpRealThe difference from the embodiment (FIG. 9) is that, instead of the electromagnet 21 and the iron piece 22, a permanent magnet 42 and a yoke 43 are provided on a fixed portion (for example, on the lens barrel 710) and fixed to the mechanical lock ring 11 in the magnetic field. The holding coil 41 is provided. During the unlocking holding, the holding coil 41 may be energized to hold the unlocking.
[0133]
In general, when a coil is driven and moved in a magnetic field, a magnetic field sufficient to sufficiently cover the driving stroke width of the coil is required, and the permanent magnet becomes large.
[0134]
However, as far as the permanent magnet 42 is concerned, the holding coil 41 is used only when holding, and its driving force does not change, so the permanent magnet 42 does not need to be enlarged and can be made compact.
[0135]
Since the mechanical lock coil 12 is driven and moved, the opposing permanent magnet 13 needs to be large enough to cover the stroke. In order to reduce the size of the permanent magnet 13, the following method is used. You can go.
[0136]
As shown in FIG. 12A, the cam surface 11a of the mechanical lock ring 11 includes an irreversible part and a reversible part. In the locked state of the shake correction means, as shown in FIG. 13 (a), the protrusion 16 is positioned at the irreversible portion of the mechanical lock ring 11, and in this state, the shake correction means swings due to disturbance. However, the mechanical lock ring is not rotated by that force.
[0137]
When energization 51a [see FIG. 13 (b)] is performed on the mechanical lock coil 12 in order to release the lock from this state, the mechanical lock ring 11 starts to rotate and enters the state of (b) in FIG. 13 (a). Then, the protrusion 16 enters the reversible portion of the cam surface 11a (locking means rotation: 52a).
[0138]
Next, when the shake correcting means is driven in the direction of the arrow 55 as shown in FIG. 13A, the protrusion 16 pushes the cam surface 11a and the mechanical lock ring 11 is rotated. When the mechanical lock ring 11 has finished rotating to the region where the holding means (electromagnet or holding coil) works, the shake correction means is returned to the original position (see (d) of FIG. 13A).
[0139]
The relationship between the permanent magnet 13 facing the mechanical lock coil 12 is as shown in FIG. 12 (b) ((b) in FIG. 13 (a) is the position in the locked state). , 12b are in magnets 13a, 13b (opposite polarities), so that when the mechanical lock coil 12 is energized, its thrust can be used effectively (at this time, the mechanical lock ring 11 is at the start of unlocking). Thereafter, the mechanical lock coil 12 moves in the direction of the arrow 56, and this thrust is weakened each time the effective portion 12a is detached from the magnet 13a. In order to prevent this, the permanent magnet 13 and the mechanical lock coil 12 must be enlarged in the moving direction. However, even if the thrust is weakened, if the protrusion 16 is in the reversible portion of the cam surface 11a at this time, the mechanical lock ring 11 can be rotated by the driving force of the shake correcting means, so that the thrust can be compensated.
[0140]
Therefore, "Reliable unlocking is possible with compact and power-saving locking means"aboutCan be achieved.
[0141]
As another method of utilizing the operation of the shake correction means for the locking means, it can be used at the time of locking, contrary to the above-described unlocking.
[0142]
Since the mechanical lock ring 11 is elastically biased in the locking direction by the mechanical lock spring 15 at the time of locking, the mechanical lock ring 11 is rotated in the locking direction by the mechanical lock spring 15 at the time of locking driving, and when locking is completed. An impact sound is generated in contact with the stopper 11b. In order to reduce this sound, the mechanical lock coil 12 has been used (short circuit, reverse energization) in the examples so far. However, paying attention to the fact that the rotational angular velocity of the mechanical lock ring 11 is slow at the start of rotation and becomes high at the end of the rotation and a large impact sound is generated. As a method for preventing the occurrence of this, a shake correction means is used as shown in FIG.
[0143]
As shown in FIG. 14A, at the start of locking, the support frame 72 of the shake correction means is moved in the direction of the arrow 61 (the shake correction means is driven). In this state, when the mechanical lock ring 11 is rotated in the locking direction by the force of the mechanical lock spring 15, the protrusion 16 immediately after the rotation is brought into contact with the cam surface 11a (therefore, the impact sound is small).
[0144]
Next, when the shake correction means is driven in the direction of the arrow 62 (for example, returned to the center for about 1 second) as shown in FIG. Since the mechanical lock ring 11 moves away from the cam surface 11a, the mechanical lock ring 11 rotates in the direction of the arrow 17, and the locking is completed silently as shown in FIG.
[0145]
FIG. 14B shows a timing chart during the above operation, and the image stabilization is performed up to the point of the arrow 67 (the position 63a of the image stabilization means is performing the image stabilization operation).
[0146]
Here, if the image stabilization is turned off at the position of the arrow 67 (waveform 66), the shake correction means is driven in the direction of the arrow 61 at this time (waveform 636). At this time, the mechanical lock ring 11 starts a locking operation (stops the locking release holding) (waveform 65 is a locking start signal). Thereafter, when the shake correction means is slowly returned to the center as shown by the waveform 63c, the mechanical lock ring 11 is also rotated slowly as shown by the waveform 64, and at 64a, the mechanical lock ring 11 contacts the stopper 11b to complete the locking. To do.
[0147]
By the above method, the mechanical lock coil 12 is not energized“"Lower the driving sound of the locking means when locking and unlocking"aboutCan be achieved.
[0148]
(Modification)
The present invention assumes a shift optical system that moves an optical member in a plane perpendicular to the optical axis as shake correction means, but in a plane perpendicular to the optical axis, such as a light flux changing means such as a variable apex angle prism. It may be one that moves the imaging surface.
[0149]
Further, the present invention has been described as applied to cameras such as a single-lens reflex camera, a lens shutter camera, and a video camera. However, the present invention can also be applied as other optical devices and other devices, and further as a constituent unit. It is.
[0151]
【The invention's effect】
As explained above, according to the present invention,The shake correction means that achieves power saving when holding the shake correction means in the unlocked state, and can stably lock the shake correction means by the locking means in any state such as when the power is cut off. A locking device can be made.
[Brief description of the drawings]
FIG. 1 shows the first of the present invention.Prerequisite technology examplesIt is a disassembled perspective view which shows the shake correction means latching device which concerns on.
2 is a mechanism diagram showing a locked state and a locked release state of a shake correction unit by the locking device of FIG. 1. FIG.
FIG. 3 is a timing chart showing an operation when power is supplied to the mechanical lock coil 12 of FIG. 1;
4 is a diagram showing a specific example of power supply to the mechanical lock coil 12 of FIG.
5 is a timing chart showing another example of the operation when power is supplied to the mechanical lock coil 12 of FIG.
FIG. 6 shows the second of the present invention.Prerequisite technology examplesIt is a disassembled perspective view of the shake correction means locking device concerning.
7 is a mechanism diagram for explaining the locking means and the locking drive means of FIG. 6. FIG.
FIG. 8 shows the third of the present inventionPrerequisite technology examplesIt is a disassembled perspective view of the shake correction means locking device concerning.
FIG. 9 shows the present invention.oneIt is a disassembled perspective view of the shake correction means locking device concerning an example.
10 is a timing chart showing an operation at the time of locking release driving, locking release holding, and locking of the locking means of FIG. 9;
FIG. 11 shows the first of the present invention.Reference technology example 1It is a disassembled perspective view of the shake correction means locking device concerning.
12 is a mechanism diagram for explaining the structure of the locking means and the locking drive means of FIG. 11. FIG.
FIG. 13 is a diagram for explaining a series of operations when the shake correction unit itself of FIG. 11 is moved and locked by the locking unit.
FIG. 14 is a diagram for explaining a series of operations in another example when the shake correction unit itself in FIG. 11 is moved to perform locking by the locking unit.
FIG. 15 is a mechanism diagram showing a schematic configuration of a conventional vibration isolator.
FIG. 16 is an exploded perspective view showing a specific configuration example of the correction unit in FIG. 15;
17 is a diagram showing a drive control system of the correcting means in FIG. 16;
18 is a circuit diagram illustrating a specific configuration example of each circuit in FIG. 17;
19 is a view showing a configuration of the locking device shown in FIG.
FIG. 20 is a block diagram showing a schematic configuration of a camera provided with a conventional image stabilizer.
[Explanation of symbols]
11 Mechanical lock ring
12 Mechanical lock coil
13 Permanent magnet
14 York
15, 19 Mechanical lock spring
16 protrusion
18 Drive transmission disk
21 Electromagnet
21a York
21b Adsorption coil
22 Shingles
41 Holding coil
42 Permanent magnet
43 York
71 lens
72 Support frame
72a Holding frame
79p, 79y permanent magnet

Claims (1)

A locking means for locking a shake correction means for correcting image shake, an elastic member for urging the locking means in the locking direction, a coil and a magnetic field generating means arranged to face the coil Configured to drive the locking means when electric power is applied to the coil, and to change the shake correction means from the locked state to the unlocked state. The electromagnet and the iron piece are in contact with each other in a state in which the shake correcting means is unlocked by the driving means , the electromagnet provided in the fixing portion, and the iron piece provided in the locking means. A holding means for maintaining the unlocked state while the contact state is maintained by the supply of electric power, and when holding the unlocked state by the holding means, to the coil of the locking drive means, Stop power supply, Or, the locking, characterized in that so as to supply less power than when driving in the release state to stabilization means locking apparatus.

Images