JPH0566449A - Image blurring correction device - Google Patents

Abstract

PURPOSE:To prevent a lens barrel from being uselessly made large, to prevent aberration from excessively occurring and to improve operability in the case of performing operation such as panning or changing framing. CONSTITUTION:Limit means ICPU and SH for limiting driven displacement in two directions when the displacement of a correction optical system ILNS by two pairs of driving means IACTp and IACTy attains specified relation are provided, and when the displacement in the 1st direction and the displacement in the 2nd direction of the correction optical system attain the 1st specified relation, the displacement of the correction optical means is limited so that the correction optical system can move (displace) only in a specified range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a correction optical mechanism having two sets of driving means which are independently driven in two directions substantially orthogonal to each other in order to correct a two-dimensional image blur occurring on an image plane. The present invention relates to an improvement in an image blur correction device having a.

[0002]

2. Description of the Related Art Among various kinds of blurring occurring in a camera or the like, the one that most affects image blurring on a photographing screen is shift blurring (imaging of an image) caused by angular blurring of the photographing optical axis (flapping of the photographing optical axis). Translational movement of the image on a plane perpendicular to the optical axis, that is, on the image plane. Then, for convenience sake, the angular blur of the photographing optical axis is decomposed into angular blurs in the vertical direction (pitch direction) and the horizontal direction (yaw direction) to perform blur detection,
The two-dimensional blurring on the image plane is corrected by driving the correction optical system, which is a part of the photographing optical system, in the vertical and horizontal directions independently on the plane circle perpendicular to the photographing optical axis based on the detection signal. is doing.

As a concrete example applying this principle,
Japanese Patent Application Laid-Open No. 63-49729, Japanese Patent Application No. 1-
Applications such as 327830 have been made.

In these proposals, the correction optical system can be driven in the vertical and horizontal directions in a plane perpendicular to the photographing optical axis, so that the supporting means, the driving means, and the supporting means for the optical system can be independently driven in the vertical and horizontal directions. It has a control means.

[0005]

However, the above-mentioned conventional example has the following drawbacks. That is, the blurring direction of the photographing optical axis due to camera shake during handheld photographing falls within a cone having an apex angle 2θ ₀ with the reference direction as the center line when the direction of the photographing optical axis is used as a reference. Therefore, it is necessary for the image blur correction device to have a blur correction range of ± θ ₀ in each of the pitch and yaw directions, and the drive mechanism of the correction optical system has the above-mentioned angle ± θ _0.
The mechanical portion is designed to have a driving amount ± d ₀ corresponding to. However, in reality, in order to obtain a sufficient blur correction effect, in general, the drive amount is generally set to "± d max" which is slightly larger than the amount ± d ₀ corresponding to the actual camera shake amplitude. Then, as shown in FIG. 14, the correction optical system can be independently driven in the vertical and horizontal directions by "± dmax", but the maximum displacement "+ dmax" or "-dmax" in the vertical and horizontal directions at the same time.
When "max" occurs, the amount of displacement from the origin of the correction optical system becomes "(√2) dmax", which is approximately 1.4 times "dmax".
It also becomes. That is, judging from the camera shake characteristics, it is sufficient for the correction optical system to move within a circle having a radius of dmax with respect to the origin, but a displacement of dmax or more occurs in a certain specific direction. Moreover, although such a displacement is stochastically small, the space around the correction optical system must have a large space in consideration of this large displacement. There is a problem that the lens barrel becomes unnecessarily large.

This state is shown in FIG.

FIG. 15 is a view of the correction optical system as seen from the direction of the image plane, and L ₀ shows a space occupied when the correction optical system or a frame holding the correction optical system is located at the origin, and L ₁
Is up and L ₂ is right dmax displacement, L ₃
Shows the occupied space when it is displaced by dmax upward and is also displaced by dmax to the right. And the spaces L ₁ and L
_In the case of ₂ , the cylindrical space for accommodating these movable parts can be SP ₁ , but when the correction optical system is displaced to the state of L ₃ , the cylindrical space is up to SP _3. You will need it. That is, the lens barrel becomes thicker by the difference between the cylindrical spaces SP ₁ and SP ₃ .

On the other hand, the large displacement of the correction optical system described above causes a problem in terms of aberration.

That is, when designing the correction optical system, it is natural that aberration should be eliminated as much as possible, but in reality, the occurrence of aberration is unavoidable. The aberration depends on the displacement of the correction optical system, and when it exceeds a certain allowable displacement, the aberration sharply increases.
On the other hand, when only normal camera shake occurs, the probability that a large displacement of the correction optical system as described above will occur during image shake correction is very small, but if panning or framing changing operations are performed, it is very difficult. It may cause rank. If photography (exposure) is performed at this time, there arises a problem that a photograph with large aberration can be taken. In addition, if the shake correction possible range is too large, there is a problem that operability at the time of panning or framing change, that is, the time until the image shake correction can be restarted after the end of panning becomes long.

In view of the above points, an object of the present invention is to prevent an unnecessary enlargement of the lens barrel, prevent excessive aberrations, and improve operability during panning and framing changing operations. An object is to provide an image stabilization device.

[0011]

According to the present invention, when the displacement of the correction optical system by the two sets of driving means reaches a predetermined relationship, a limiting means for limiting the driving displacement in these two directions is provided. When the displacement of the correction optical system by the pair of driving means reaches the first predetermined relationship, the two sets of driving means are driven by the signals obtained by combining the respective drive control signals in the second predetermined relationship. Drive control means is provided.

[0012]

When the displacement in the first direction and the displacement in the second direction of the correction optical system have the first predetermined relationship, the displacement of the correction optical means is limited or each of them is driven. Second control signal
The correction optical system can be moved (displaced) only within a predetermined range by being driven by a signal combined in a predetermined relationship.

[0013]

1 to 5 are diagrams according to a first embodiment of the present invention.

FIG. 2 shows an image forming optical system used in the present invention. The focal length is a zoom of 3 times from 100 mm to 300 mm, and the wide end (f = 100 mm) is shown in the figure and the lower is shown. Tele end (f
= 300 mm) shows the lens arrangement.

This image-forming optical system is composed of four groups, and the fourth group is fixed and the first, second, and third groups are moved during zooming.
The first group moves during focus adjustment. Then, by displacing the second group in the direction perpendicular to the optical axis, the image on the image plane is displaced to perform image blur correction.

FIG. 1 is a block diagram showing a main part according to a first embodiment of the present invention.

In FIG. 1, CMR is a camera body, and LNS is an interchangeable lens detachable from the camera body CMR.

First, the structure of the camera body CMR will be described.

The CCPU is an in-camera microcomputer (hereinafter referred to as a microcomputer), which is a one-chip microcomputer having a ROM, a RAM, and an A / D conversion function. The in-camera microcomputer CCPU performs a series of camera operations such as automatic exposure control, automatic focus adjustment, film winding, etc. in accordance with the camera sequence program stored in the ROM. Therefore, the microcomputer CCPU in the camera communicates with peripheral circuits and lenses in the camera body CMR to control the operation of each circuit and lens.

LCM is a lens communication buffer circuit,
Power is supplied to the lens LNS via the power supply line VL, and output from the camera body CMR to the lens LNS via the signal line DCL and from the lens LNS to the camera body C
It serves as an inter-lens communication buffer for the output to the MR via the signal line DLC.

The SNS is a line sensor for focus detection (hereinafter simply referred to as a sensor) including a CCD and the like, and SDR is a drive circuit for driving the sensor SNS according to a command from the microcomputer CCPU in the camera, and the sensor SNS outputs the signal. The image signal is taken in, amplified, and sent to the microcomputer CCPU in the camera.

The light from the lens LNS is the main mirror M.
The light enters the photometric sensor SPC via M, the focus glass PG, and the pentaprism PP, and the output signal is input to the microcomputer CCPU in the camera and used for automatic exposure control (AE) according to a predetermined program.

DDR is a switch detection and display circuit, which switches the display of the display member DSP of the camera based on the data sent from the microcomputer CCPU in the camera and turns on various operation members (SWMD) of the camera.・ The off-state is notified to the microcomputer CCPU in the camera by communication.

SW1 and SW2 are switches interlocked with a release button (not shown). The switch SW1 is turned on when the release button is pressed in the first step, and the switch SW2 is turned on when the release button is pressed up to the second step. .. As will be described later, the in-camera microcomputer CCPU generates a start signal for photometry, automatic focus adjustment operation and image blur correction operation when the switch SW1 is turned on, and performs exposure control and film winding when the switch SW2 is turned on. The switch SW2 is connected to the "interruption input terminal" of the microcomputer CCPU in the camera, so that even if the program is executed when the switch SW1 is on, an interrupt is generated by turning on the switch SW2, and it is possible to immediately shift to a predetermined interrupt program.

MTR1 is a film feeding mode, and MTR2 is a mirror up / down mode and a shutter spring charge mode.
Each of the drive circuits MDR1 and MDR2 controls forward / reverse rotation.

MG1 and MG2 are shutter front and rear curtain running start magnets, respectively, and amplifying transistors TR1 and T
The power is supplied at R2, and the shutter microcomputer STR controls the shutter STR.

Next, the structure of the lens LNS side will be described.

LCPU is an in-lens microcomputer, which is a one-chip microcomputer having ROM, RAM, and A / D conversion functions like the in-camera microcomputer CCPU. The microcomputer LCPU in the lens adjusts the focus adjustment lens FL in accordance with a command sent from the camera body CNR via the signal line DCL.
The drive control of the NS and the drive control of the diaphragm are performed. In addition, various operating conditions of the lens (how much the focus adjustment optical system has been driven, how many stops the aperture has been stopped, etc.) and parameters (open F number, focal length, coefficient of defocus amount vs extension amount, etc.) ) Is transmitted to the camera side via the signal line DLC.

The FMTR is a driving motor for the focus adjusting lens FLNS, which rotates a helicoid ring (not shown) through a gear train to move the lens FLNS back and forth in the optical axis direction for focus adjustment.

FDR is a drive circuit of the motor FMTR, which is driven by a signal from a microcomputer LCPU in the lens.
Controls forward / reverse rotation of the FMTR and brakes.

In this embodiment, the front lens focus type is shown as an example. When a focus adjustment command is sent from the camera body CMR, the motor is moved in accordance with the driving amount and direction sent at the same time. The FMTR is driven to move the focus adjustment lens FLNS in the optical axis direction to perform focus adjustment.
The amount of movement of the focus adjustment lens FLNS is monitored by a pulse signal of the encoder circuit ENCF, and is counted by a counter in the lens microcomputer LCPU. When the predetermined movement is completed, the motor FMTR is set. Control.

Therefore, once the focus adjustment command is sent from the camera body CMR, the camera microcomputer CCPU
Does not need to be involved in lens driving at all until the lens driving is completed. Further, the contents of the counter can be sent to the camera body CMR if necessary.

ENCB is an encoder for detecting the absolute position of the focus adjusting lens FLNS, ENCZ is an encoder for detecting the zoom position, both of which are code patterns provided on the helicoid ring and the zoom ring. And a signal detected by a known method such as a brush and a detection brush is sent to the in-lens microcomputer LCPU.

When an aperture control command is sent from the camera body CMR, a stepping motor D known for driving the aperture is used according to the number of aperture steps sent at the same time.
Drive the MTR.

The ICPU is an image blur correction microcomputer, which controls the image blur correction operation and controls the lens LNS from the camera body CMR.
To the camera body CMR from the lens LNS, and the output signal from the microcomputer ICPU is input to the lens microcomputer LCPU. That is, communication with the microcomputer CCPU in the camera is performed only with the microcomputer LCPU in the lens, and the image stabilization microcomputer IC
The PU takes a form of intercepting communication between the two. Communication from the image blur correction microcomputer ICPU to the camera microcomputer CCPU is performed by the lens microcomputer LCPU.
Through.

AD is an angular displacement meter for detecting the blurring of the lens LNS. For example, Japanese Patent Application No.
A sensor utilizing the inertia of the fluid in the cylindrical case such as No. 201183 is used. The angular displacement output θ of the angular displacement meter
Is transmitted to the image blur correction microcomputer ICPU. Further, the image blur correction microcomputer ICPU sends control signals SAD1 and SAD2 for controlling the response frequency characteristic of the angular displacement meter.

ICNT is an image blur correction control circuit described later, which has a filter, an amplifier, a switch, etc., and drives and controls an image blur correction actuator IACT, which will be described later. It has a signal input / output line.

ILNS is a correction optical system which is an optical axis eccentric means, and is supported by a guide mechanism described later, and can move in parallel to a plane perpendicular to the optical axis.

The IACT is an image blur correcting actuator provided in the support mechanism, and is composed of a magnetic circuit made of a permanent magnet and a coil moving in the magnetic circuit to displace the correction optical system ILNS. ..

PSD is a position detecting sensor for detecting the position of the correction optical system ILNS, which is an infrared light emitting diode IRE.
The light from D passes through the slit SLT that moves integrally with the correction optical system ILNS and is incident on the light receiving surface of the position detection sensor PSD, so that the position detection sensor PSD causes the position of the incident light, that is, the correction optical system ILNS. Position signal (displacement amount d
_L ) is generated. The position signal (d _L ) is used as the image blur correction microcomputer ICPU and the image blur correction control circuit ICN.
Input to T.

SWIS is a main switch of the image blur correction system. When the switch SWIS is turned on, the image blur correction microcomputer ICPU and its peripheral circuits are powered on, and the image blur correction control circuit ICNT starts operating. When the switch SW1 of the camera body CMR is turned on, this signal is communicated to the image blur correction microcomputer ICPU via the lens microcomputer LCPU, and the motor IMTR is driven to start the image blur correction operation.

Next, the angular displacement meter AD which is a detection sensor will be described with reference to FIGS.

The basic configuration of the angular displacement meter AD is almost the same as that proposed in Japanese Patent Application No. 2-201183 by the present applicant. Here, the control circuit is slightly modified and simplified. Explain.

First, the mechanical components will be described.

The inside of the cylindrical outer cylinder 21 is filled with a liquid, and the floating body 22 is supported in the liquid so as to be freely rotatable around a bearing 27. Further, a light projecting element 25 and a light receiving element 26 for optically detecting the movement of the floating body 22 are arranged as shown in FIG.
2 and a yoke 23 forming a closed magnetic circuit, and this yoke 23
A winding coil 24 is arranged between the portion and the floating body 22.

Next, the electrical components will be described.

The portion A surrounded by the dotted line is a position detecting portion for detecting the position of the floating body 22 with respect to the outer cylinder 21, and the infrared light emitted from the light projecting element 25 is reflected by the floating body 22. This is a basic configuration in which light is detected by the position detection light receiving element 26.
The photocurrents Ia and Ib generated in the light receiving element 26 are shunted according to the position of the center of gravity of the infrared light incident on the light receiving element 26 as is known, and are differentially amplified by the operational amplifier 28, and the angular displacement of the floating body 22, ie, the lens mirror Outputs the displacement angle (θ) of the cylinder.

A portion B surrounded by a dotted line is a control portion for changing the parameter of the sensor. In the figure, two switches SWAD1 and SWAD2 are image blur correction microcomputer I.
A switch which is on / off controlled by the CPU on the control lines SAD1 and SAD2. When the line goes high, the switch is turned on (closed). When the switch is off (open), the angular displacement output θ is the operational amplifier 29.
Is amplified by an amplification factor of "R ₃ / R ₀ ", but when the switch is turned on, the resistance R ₀ or the resistance R ₁ or the resistance R ₂
Are connected in parallel, and as a result, the combined resistance decreases, and the amplification factor increases. Then, for example, "R ₀ = R ₁ = R ₃ = 2R
₂ ", the amplification factor of the operational amplifier 29 by turning on / off the switch is set as shown in FIG. 3 (b).

The portion C surrounded by the dotted line is the winding coil 24.
The operational amplifier 30 serves as a buffer in the driver unit for driving the. Therefore, a current according to the output voltage of the control unit B flows through the winding coil 24. That is, since the coil current proportional to the angular displacement (θ) of the floating body 24 flows, the floating body 24 is given a restoring force proportional to the angular displacement (θ), and this restoring force is switched by the size of the switches SWAD1 and SWAD2. be able to. The greater the restoring force, the more quickly the angular displacement output θ converges to “0”, and the sensor characteristic has a high high-pass characteristic, that is, the low-frequency shake detection capability becomes low.

The angular displacement output θ saturated during panning escapes quickly from the saturated region.

The startup time of the sensor when the power is turned on is shortened. And so on.

In FIG. 1, the image blur correction mechanism is shown for only one axis, but camera shake occurs in the two-dimensional directions of up, down, left, and right. Therefore, the actual lens detects blur in the two-axis directions, and the correction optical system. ILNS must also work two-dimensionally.

Therefore, FIG. 4 shows in detail the support mechanism of the correction optical system ILNS. In this correction optical mechanism, a correction lens 41 corresponding to the correction optical system ILNS in FIG. 1 is operated in a direction of correcting camera shake in a plane orthogonal to the optical axis, thereby obtaining an image shake suppressing effect on the image forming surface. Is.

The correction lens 41 can be freely driven in two directions (pitch 42p and yaw 42y) orthogonal to the optical axis and perpendicular to each other. The structure is shown below.

In FIG. 4, a fixed frame 43 for holding the correction lens 41 is a slide bearing 44 made of polyacetal resin (hereinafter referred to as POM) fixed to the arm-shaped projections 43a and 43b.
It is possible to slide on the pitch slide shaft 45p via p. Further, the pitch slide shaft 45p is attached to the holding frame 46.
Is attached to the protrusion 46a. Further, a pitch coil 48p is attached to the fixed frame 43. Pitch coil 4
8p is pitch magnet 49p and pitch yoke 410p
The fixed frame 43 is driven in the pitch direction 42p by passing an electric current. The pitch coil 48p is provided with a slit 411p,
The position of the fixed frame 43 in the pitch direction 42p is detected by the relation between the light projector 412p (infrared light emitting diode IRED) and the light receiver 413p (semiconductor position detection element PSD).

The above is the drive mechanism in the pitch direction.

Next, the drive mechanism in the yaw direction (direction of the arrow 42g) will be described.

The protrusions 46b and 46c on the holding frame 46 have P
A slide bearing 44y such as OM is mounted. On the other hand, a yaw slide shaft 45y is fixedly mounted on a protrusion 414a on a housing 414 attached to a lens barrel (not shown). Since the bearing 44y can slide on the shaft 45y, the holding frame 46 and the fixed frame 43 can also move in the yaw direction (arrow 42y direction). Further, the fixed frame 43 is provided with a yaw coil 48y, and a yaw magnet 49y sandwiching the yaw coil is provided.
The fixed frame 43 is also driven in the yaw direction 42y by the interaction of the magnetic field formed by the yaw yoke 410y. The yaw coil 48y is provided with a slit 411y to detect the position of the fixed frame 23 in the yaw direction 42y as in the pitch direction. The driving of the correction lens 41 in the pitch direction 42p and the yaw direction 42y has the configuration shown in FIG.

The flat portion 43c provided on the lower left portion of the fixed frame 43 is restricted in its position in the optical axis direction by a shake-preventing projection 50 provided on a lens barrel fixing portion (not shown). This is because the position restricting portion of the fixed frame 43 is 43a, 43b in the pitch direction and 46b, 46 in the yaw direction in the above-mentioned configuration.
This is because there are two positions, c, and at least three position restriction parts (holding parts) are required to restrict the action of the fixed frame 43 only in the shift direction. Therefore, two protrusions 50
The position of the flat surface portion 43c is regulated from the front and back sides (one on the back side is not shown) to prevent the fixed frame 43 from moving (flaking) in the optical axis direction.

In the above structure, the correction lens 41 can be driven independently in the pitch direction and the yaw direction.

Next, the drive circuit of the above correction optical support mechanism will be described.

FIG. 5 shows the image blur correction control unit in detail. The portion surrounded by the dotted line corresponds to the image blur correction control circuit ICNT of FIG. The circuit ICNT, the angular displacement meter AD, etc. are provided for driving the pitch direction and the yaw direction, respectively. Each of the elements for the pitch direction and the name of the signal line have p for the yaw direction. Is added with the subscript of y.
However, in the following description, the pitch and yaw directions will be collectively described, and the subscripts p and y will be omitted.

AD is the above-mentioned angular displacement meter, which outputs the shake angular displacement (θ) of the lens barrel. SAD1 and SAD2 are control lines for changing the blur detection characteristic of the angular displacement meter AD described above. When the lines SAD1 and SAD2 are at a high level, the AD high pass characteristic of the angular displacement meter is enhanced to improve the detection capability for low frequency blur. It is configured to decrease. That is, when the angular displacement output θ is saturated by an operation such as panning, the lines SAD1 and SAD2 are appropriately set to the high level to expedite the return of the angular displacement output θ to “0”.

The angular displacement output θ is a shake correction microcomputer ICP.
The coefficient is converted in U to become the control signal d, which is input to the sample hold circuit SH in the image blur correction control circuit ICNT. The sample-hold circuit SH is controlled by the control line SSH from the shake correction microcomputer ICPU, and when the line SSH is low level, the control signal d changes the circuit SH.
When the line SSH is at the high level, the control signal d at the time when the line is at the high level is held and continuously output.

SWACT is a switch for turning on / off the control signal input to the actuator IACT. The switch SWA is controlled by the blur correction microcomputer ICPU.
When the CT is turned on, the driving of the actuator IACT is started and the blur correction operation is started.

COMPE is a phase compensation circuit for increasing the stability of the feedback loop system, and this output signal V
_ACT becomes the applied voltage to the actuator IACT.

When the actuator IACT operates, the correction optical system ILNS is driven, and the IR fixed to the slit SLT and the lens barrel which moves integrally with the optical system ILNS.
Due to the action of ED and PSD, the displacement signal d _L of the correction optical system ILNS is output from PSD. Then, the signal d _L
Is inversely input to the addition point P1 to form a feedback loop with d as a control amount, and the correction optical system I
The LNS is driven and controlled by the displacement corresponding to the control signal d.

The above is the configuration of the present embodiment. Next, the blur correction principle, that is, the relationship between the blur angle displacement (θ) and the lens drive amount (d _L ) and the image movement amount (displacement amount) d _IM will be described. .. Assuming that the focal length of the photographic optical system ILNS is f and the photographic magnification is β, the photographic optical system is θ [rad
] The amount of image displacement d _IM when the angular blur occurs is d _IM = f (1 + β) · θ. On the other hand, if the ratio of the image displacement d _{IM to} the displacement d _L of the correction optical system ILNS is referred to as the eccentricity sensitivity S _d , then d _IM = S _d · d _L. Since the eccentricity sensitivity S _d is a function of the focal length f and the photographing magnification β, it can be expressed as S _d = S _d (f, β). The principle of image blur correction is to eliminate the image blur (formula) due to the angular blur of the photographing optical system by the image displacement (formula) due to the lens displacement. Therefore, using = and the formula, d = d _L = (d _IM / S _d ) = {f · (1 + β) · θ} / {S _d (f, β)} = kθ ………… or θ = {S _d (f, β) · d _L } / {f · (1 + β)} = d _L / k ...

Next, the operation of the first embodiment of the present invention will be described with reference to FIG.

Similar to FIG. 13, FIG. 6 shows the correction optical system ILN.
In the diagram for explaining the displacement of S, the vertical axis is the vertical displacement for correcting pitch shake, and the horizontal axis is the horizontal displacement for correcting yaw shake, which corresponds to the directions of arrows 42 _p and 42 _{y in} FIG. And are represented by d _p and d _y , respectively. The movable range of the correction optical system ILNS is within a circle of radius dmax centered on the origin O. That is, the correction optical system ILNS can be displaced to ± dmax alone in the d _p or d _y directions, but the displacement is regulated at an equal interval d max from the origin O in the oblique direction, and d _p , d _y Does not reach ± dmax.

Trajectories TR1, TR2 and TR3 are trajectories of the correction optical system ILNS during execution of image blur correction in this embodiment. When the image blur correction is started, the correction optical system ILNS
Starts to be driven from the origin O and is displaced along the locus TR1. Then, when the correction optical system ILNS reaches the circle CR1, in the present invention, the place which should be originally driven along the locus TR2 is stopped during this period and waited at the point P1, and the displacement signal to be controlled is within the circle CR1. When returning to, the correction optical system IL
NS moves from the point P1 to P2 and is controlled by the locus TR3 thereafter.

Next, the camera body CMR having the above structure
The operation of each of the lens and the lens LNS will be described with reference to FIGS. 7 and 8.

First, the operation of the camera body CMR side will be described using the flowchart of FIG.

When a power switch (not shown) on the camera body CMR side is turned on, power supply to the microcomputer CCPU in the camera is started, and the operation from step (002) is started after step (001).

In step (002), the state of the switch SW1 which is turned on by pressing the release button in the first step is detected. When SW1 is off, the process proceeds to step (003) and the RAM in the microcomputer CCPU in the camera is stored. Clears and initializes all set control flags and variables,
Proceed to step (004). In step (004), the lens L
A command to stop the image blur correction operation (IS) is transmitted to the NS side.

The above steps (002) to (004) are performed by the switch S.
The process is repeated until W1 is turned on or the power switch is turned off.

When the switch SW1 is turned on, the process proceeds from step (002) to (011).

In step (011), lens communication is performed.
This communication is communication for obtaining information necessary for performing exposure control (AE) and focus adjustment control (AF), and when the camera microcomputer CCPU sends a communication command to the lens microcomputer LCPU via the signal line DCL. The in-lens microcomputer LCPU transmits information such as the focal length, the AF sensitivity, and the open F number stored in the ROM via the signal line DLC.

In step (012), a command to start the image blur correction operation is transmitted to the lens LNS side. Step (01
In 3), the "photometric" subroutine for exposure control is executed. That is, the in-camera microcomputer CCPU inputs the output of the photometric sensor SPC shown in FIG. 1 to the analog input terminal and performs A / D conversion to obtain the digital photometric value Bv. In step (014), an "exposure calculation" subroutine for obtaining the exposure control value is executed. In the subroutine, the shutter value Tv and the aperture value Av are determined according to the apex arithmetic expression "Av + Tv = Bv + Sv" and a predetermined program diagram, and these are stored in a predetermined address of the RAM.

In step (015), the "image signal input" subroutine is executed. Here, the camera microcomputer CCP
U inputs an image signal from the sensor SNS for focus detection. In step (016), the defocus amount of the taking lens is calculated based on the input image signal.

The subroutine flow of the steps (015) and (016) is the same as that of the applicant of the present invention.
No. 4, etc., and detailed description thereof is omitted here.

In step (017), the "lens drive" subroutine is executed. In the subroutine, the camera body C
The drive pulse number of the focus adjustment lens FLNS calculated in step (016) on the MR side is set to the microcomputer LCPU in the lens.
To the microcomputer LCPU in the lens after that
Drives and controls the motor FMTR according to a predetermined acceleration / deceleration curve. After the driving is completed, an end signal is transmitted to the microcomputer CCPU in the camera, the subroutine is completed, and the process returns to step (002).

Next, the above step (015) surrounded by a broken line.
The case where a release interrupt by turning on the switch SW2 is entered during execution of each operation in the focus adjustment cycle shown in (017) to (017) will be described.

As described above, the switch SW2 is connected to the interrupt input terminal of the in-camera microcomputer CCPU, and when the switch SW2 is turned on, the step immediately proceeds to the step (021) by the interrupt function while executing any step. It is configured to migrate.

When the switch SW2 interrupt is entered during execution of the step surrounded by the broken line, the process proceeds to step (022) via step (021).

At step (022), the release operation is performed. Then, in the next step (023), the film is wound to finish the photographing for one frame, and the process returns to step (002).

The subroutines of steps (013) to (017) and steps (022) and (023) are already known and will not be described in detail.

Next, the image blur correction operation performed on the lens LNS side will be described using the flowchart of FIG. In each step, the suffix _{p y} is added to indicate that the pitch and yaw motions are sequentially performed.

In step (101), the image blur correction main switch SWIS is turned on to turn on the image blur correction microcomputer ICPU, its peripheral circuits, and the angular displacement meter AD. As a result, the image blur correction microcomputer ICPU starts executing the program after step (102) in FIG. In step (102), the image blur correction microcomputer ICPU
Clear all flags and all variables in and set to "0".
In step (103), control lines SAD1 _py and SAD2
Angular displacement output of angular displacement meter AD _py with _py as high level θ _py
The strong high-pass characteristic is given to the lens so that the displacement of the correction optical system ILNS starts from a state close to the origin at the start of image blur correction.

In step (104), the control line SSH _py
Is allowed to pass the control displacement d _py . In step (105), an image blur correction (IS) start command is discriminated, and when the IS start command is not received from the camera body CMR, the process proceeds to step (106). Step (10
In 6), the switch SWACT _py is turned off (open) to prohibit the input of the control signal to the actuator IACT _py , that is, the image blur correction operation is prohibited. And step (1
Return to 03) and repeat steps (103) to (106). In this state, image blur correction is not performed.

If an IS start command is received from the camera body CMR while executing steps (103) to (106),
From (105), the process proceeds to step (111).

In step (111), the control line SAD1
_py and SAD2 _py are set to the low level, and the shake detection characteristic of the angular displacement meter AD _{py is set to} the camera shake correction compatible state. Step (11
In 2), the switch SWACT _py is turned on to start image blur correction.

At step (113), encoders ENCZ, E for detecting the zoom ring position and the focus adjusting lens position.
The state of NCB is detected, and the focal length f, the imaging magnification β and the eccentricity sensitivity S _d (f, β) at that time are read from the data stored in the ROM based on the output information.

Here, the eccentricity sensitivity S _d represents the ratio of the image displacement amount d _IM to the displacement amount d _L of the correction optical system ILNS as described in the above equation, and S _d = d _IM / d _L expressed. The eccentricity sensitivity S _d is a function of the focal length f and the focus adjustment lens position, that is, the photographing magnification β. Therefore, the sensitivity S _d is the matrix data S _d (f,
β) is stored in the ROM as the above encoder ENC
It is read from the ROM by the information of Z and ENCB.

Next, at step (114), the blur angle θ in the above equation is calculated as the control displacement d of the correction optical system ILNS.
The coefficient k to be converted to is calculated. In step (115),
The shake angle displacement θ _p in the pitch direction is converted into a displacement control value d _p of the correction optical system ILNS, and output to the input end of the sample hold circuit SH _p . Then, in step (116), the same operation as in step (115) is performed in the yaw direction.

In step (117), the correction optical system ILNS
The displacement amount from the origin of is calculated and stored in dr. In step (118), the displacement amount dr and the displacement allowable amount dmax are discriminated from each other. If "dr <dmax", that is, if the displacement of the correction optical system ILNS is within the circle CR1 in FIG.
Proceed to (119) to continue image blur correction. In step (119), the control lines SSH _p and SSH _y are set to low level, the sample hold circuits SH _p and SH _y are deactivated, and the signals d _p and d _y are passed. In step (120), the control lines SAD1 _p and SAD1 _y are set to the low level, and the shake detection characteristics of the angular displacement meters AD _p and AD _y are set to the camera shake correction compatible state. That is, steps (119), (1
In 20), the normal image blur correction operation is performed.

On the other hand, in step (118), "dr≥d
max ”, that is, when the displacement of the correction lens ILNS is going to go out of the circle CR1 in FIG. 6, the process proceeds to step (121), and in this step (121), the control line SSH _p
And SSH _y to high level. Then, the outputs of the sample and hold circuits SH _p and SH _y are fixed to the input values at that time. Therefore, the displacement of the correction optical system ILNS remains fixed at the point P1 on the circle CR1 in FIG. 6, and the image blur correction is interrupted.

In step (122), the control line SAD1
_By setting _p and SAD1 _y to high levels, the angular displacement gauges AD _p and AD _y are given a high-pass characteristic, and the output signal d _p thereof quickly returns to zero to help restart the image blur correction.

After executing step (120) or (122), the process proceeds to step (123).

In step (123), it is judged whether or not the IS stop command is received from the camera body CMR, and if not received, the process returns to step (113) and the above step (11) is executed.
3) Perform the flow from step (123).

When the flow returns to the state of "dr <dmax" in step (118) during execution of the above flow, step (11)
9) The steps of (120) are executed to resume normal image blur correction. At this time, the displacement of the correction optical system ILNS is shown in FIG.
From point P1 to point P2, and from point P2 to trajectory T
Image blur correction is performed according to R3.

In step (123), the camera body CMR
When it recognizes that the IS stop command has been transmitted from, it returns to step (103) and stops the image blur correction in step (106).

The flow of steps (113) to (123) is as follows.
Is repeated in a cycle of several milliseconds, so
Sufficient correction can be made for camera shake having a band of about 10 Hz.

In the first embodiment, the correction optical system ILN is used.
Although the movable range of S is set within a circle centered on the origin O, it is possible to set a region having another shape, which will be described below as a second embodiment.

FIG. 9 is an explanatory view of the operation of the second embodiment of the present invention, which has the same coordinate axes as in FIG.

In this figure, the movable range of the correction optical system ILNS is restricted to the inside of the octagon as shown in the figure, and the conditional expressions that satisfy this area are | d _p | <dmax and | d _y | <dmax | D _p | + | d _y | <(3/2) d max.

FIG. 10 is a control flow chart of the second embodiment, which is different from FIG. 8 in the first embodiment in that step (117) and subsequent steps are changed to step (131) and subsequent steps.
Therefore, only this changed portion will be described.

In FIG. 10, steps (115), (116)
In pitch, yaw - performs direction control displacement d _p, after calculating the d _y, the displacement restriction of the step (131) to (135) in the pitch direction.

First, in step (131), the magnitude of the pitch direction displacement d _p and the displacement allowable amount d max is discriminated, and “| d _p
If | <dmax ", execute steps (132) and (133),
Continue normal image blur correction.

On the other hand, if “| d _p | ≧ d max”, step
At (134) and (135), the image blur correction in the pitch direction is interrupted,
Strengthens the high-pass characteristics of the angular accelerometer AD _p .

In the next steps (136) to (140), the yo
For the direction, the same operations as in steps (131) to (135) above are performed.

The above is the operation of interrupting the image blur correction when the displacement in the pitch or yaw direction alone is saturated.

Then, in step (141), "│d _p │
+ | D _y | ”and“ (3/2) d max ”are compared. This is a step of determining whether the position of the ILNS of the correction optical system in FIG. 9 is outside or inside the 45 ° boundary lines of the four corners in the octagonal region. And
If the correction optical system ILNS is inside the 45 ° line, the process proceeds to step (144) without doing anything. On the other hand, if it is on the outside, the process proceeds to step (142) to operate the sample hold circuits SH _p and SH _y in the pitch and yaw directions to fix the displacement of the correction optical system ILNS and interrupt the image blur correction. To do.
Then, in step (143), the high-pass characteristics of the pitch and yaw angular displacement gauges AD _p and AD _y are enhanced.

Then, at step (144), the IS stop command is recognized. If NO, steps (113) to (143) are repeatedly executed, and if YES, the process returns to step (103) to stop the image blur correction.

The effect of the above flow will be described again with reference to FIG.

When the image blur correction is started, the correction optical system ILN
S moves on the locus TR4 according to the control signal. Then, when entering the area of the locus TR5, the steps shown in the flowchart of FIG.
The displacement is fixed at the point P3 at (141), (142) and (143). When the control signal returns to the controllable area,
The point P3 suddenly shifts to the point P4, and the drive control is restarted on the locus TR6.

In the first and second embodiments, the image blur correction is completely interrupted while the correction optical system is regulated by displacement, so that when the image blur correction is restarted, for example, as shown in FIG. In the first embodiment, the correction optical system ILNS moves from the point P1 to the point P1.
Since it rapidly moves to 2, the photographer feels uncomfortable.

Therefore, in the third embodiment of the present invention described below, when the displacement control signal of the correction optical system ILNS exceeds the allowable limit area, the correction optical system ILNS is continuously driven along the area. It is something that I have done.

FIG. 11 is a diagram for explaining the operation of the third embodiment, in which the movable permissible area of the correction optical system ILNS is the first.
The circle CR1 is the same as in the above embodiment. However, when the control displacement locus of the correction optical system ILNS is outside the circle CR1, that is, on the locus TR2, the correction optical system ILN to be actually controlled.
The displacement of S is set so as to pass through the intersection point with the perpendicular line drawn from the locus TR2 to the circle CR1, that is, the points P5, P6 and P7. Therefore, when the control command signal is the locus TR2, the actual control locus smoothly moves on the circular arc from the point P1 to the point P2.

FIG. 12 is a control flow chart of the third embodiment.

This flow is different from the flow of FIG. 8 in the first embodiment in that step (121) includes steps (151), (1
Only the changed part will be explained because it is different only in 52).

In step (117), the displacement dr of the correction optical system ILNS from the origin O is calculated, and if dr exceeds the allowable value dmax in step (118), the process proceeds to step (151).

In steps (151) and (152),
Calculate the coordinates of the intersection of the point on the locus TR2 calculated in (115) and (116) with the perpendicular drawn to the circle CR1, that is, the intersection of the line connecting the point on TR2 and the origin 0 and the circle CR1, These are newly set as pitch and yaw displacement control values d _p and d _y . Therefore, even if the displacement control value calculated in steps (115) and (116) is the locus TR2, the actual correction optical system ILN
The control locus of S is an arc TR7 (see FIG. 11) connecting P1, P5, P6, P7, and P2.

Therefore, the correction optical system ILN during image blur correction is
The locus of S is TR1 → TR7 → TR3, and it does not go outside the circle CR1 and is not interrupted on the way.

The third embodiment is the same as the second embodiment shown in FIG.
It is easy to provide the effect shown in the embodiment. Also in this case, if the correction optical system ILNS is going to go out of the octagonal displacement allowable range, the intersection of the perpendicular line drawn from the displacement control point to the opposite octagonal side may be set as the actual control point.

According to each of the above embodiments, in the correction optical system that is independently supported and driven in the two-dimensional direction, in the rectangular or square drivable area on the two-dimensional plane of the correction optical system, The maximum displacement in the diagonal direction is regulated by a function of the displacement in the first direction and the displacement in the second direction so that excessive displacement does not occur in the correction optical system. No extra displacement occurs. As a result, (1) useless enlargement of the lens barrel can be avoided.

(2) The operability during the panning or framing changing operation is improved.

(3) It is possible to prevent excessive aberration from occurring. It is possible to obtain effects such as

In the first to third embodiments, the correction optical system prohibits the two-dimensional drive area from entering the diagonal area, but in the fourth embodiment shown below, the Instead of permitting the entry into the corner area, the release is prohibited to suppress the occurrence of aberration during exposure.

FIG. 13 is a flow chart showing the operation in the fourth embodiment of the present invention. In the flow chart of the second embodiment shown in FIG. 10, step (142) is deleted,
Steps (161) to (167) are added. Therefore,
Here, only the changed portion will be described.

At the step (161) following the step (112), the flag FLG2 for permitting / prohibiting the interrupt operation of the switch SW2 is cleared to "0".

If "NO" is determined in the step (131),
In step (162), "1" is added to the flag FLG2. Similarly, if "NO" is determined in step (136), "1" is added to the flag FLG2 in step (163).

If "NO" is determined in the step (141),
In the second embodiment, the sample hold circuit SHpy was operated to latch the position of the correction optical system in the step (142), but in this embodiment, the latching is not performed, and the step (164) is performed. "1" is added to the flag FLG2.

At step (165), the state of the flag FLG2 is determined. Then, if it is determined “YES” in all steps (131), (136), (141), the correction optical system I
In the LNS, the image blur correction is normally performed in the octagonal area in FIG. 9. At this time, since “FLG = 0”, the process proceeds to step (166), and communication that allows the SW2 interrupt to the camera side. Then, the process returns from step (144) to (161).

Therefore, the switch SW is activated during this flow execution.
When 2 is turned on, the interrupt operation after step (021) in FIG. 7 is executed.

On the other hand, if any of the steps (131), (136) and (141) is determined to be "NO", "FLG≥
1 ”, so proceed to step (167) and switch to the camera side
2 Performs communication that prohibits interrupts. Therefore, in this case, the release operation is prohibited even if the switch SW2 is turned on.

Therefore, in this embodiment, the correction optical system IL
Although it is possible for the NS to enter the diagonal area of FIG. 9, release in this state is prohibited, and a photograph with large aberration is prevented from being taken.

(Modification) In the first to fourth embodiments, the image blur correction is performed by shifting a part of the lens group of the photographing optical system in the direction perpendicular to the optical axis, but this is variable. The same effect can be obtained when the apex angle prism is used. The variable apex angle prism is disclosed in Japanese Patent Application Laid-Open No. 2-5971 by the present applicant.
A liquid is enclosed between two parallel plane glasses as proposed in No. 8 and the like, the relative angle of the glasses is changed to give a prism action, and the optical axis is tilted to perform image blur correction. The prism driving mechanism also has a mechanism for independently supporting and driving in the pitch and yaw directions in order to decompose and correct the pitch and yaw. Therefore, if the angle control values of the two glasses of the prism are controlled by the flow of the first to fourth embodiments, the same effect can be obtained.

[0139]

As described above, according to the present invention,
When the displacement of the correction optical system by the two sets of driving means reaches a predetermined relationship, limiting means for limiting the drive displacement in these two directions is provided, and the displacement of the correction optical system by the two sets of driving means is the first. Drive control means for driving the two sets of drive means by a signal obtained by combining the respective drive control signals in a second predetermined relationship when the predetermined relationship is reached. When the displacement in the direction and the displacement in the second direction have the first predetermined relationship, the displacement of the correction optical means is limited,
Alternatively, each of the drive control signals is driven by a signal that is combined in a second predetermined relationship so that the correction optical system can move (displace) only within a predetermined range. Therefore, it is possible to prevent the lens barrel from being unnecessarily increased in size, prevent excessive aberrations, and improve operability during panning and framing changing operations.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a camera provided with a device of a first embodiment of the present invention.

FIG. 2 is a diagram showing an imaging optical system used in each embodiment of the present invention.

FIG. 3 is a diagram showing a mechanical and electrical configuration of the angular displacement meter according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a correction optical mechanism in the first embodiment of the invention.

FIG. 5 is a block diagram showing an image blur correction control circuit according to the first embodiment of the present invention.

FIG. 6 is a diagram for explaining the operation of the first embodiment of the present invention.

FIG. 7 is a flowchart showing the operation on the main body side of the camera including the apparatus according to the first embodiment of the present invention.

FIG. 8 is a flowchart showing an image blur correction operation on the lens side provided with the apparatus of the first embodiment of the present invention.

FIG. 9 is a diagram for explaining the operation of the second embodiment of the present invention.

FIG. 10 is a flowchart showing an image blur correction operation on the lens side including the apparatus of the second embodiment of the present invention.

FIG. 11 is a diagram for explaining the operation of the third embodiment of the present invention.

FIG. 12 is a flowchart showing an image blur correction operation on the lens side including the apparatus of the third embodiment of the present invention.

FIG. 13 is a flowchart showing an image blur correction operation on the lens side including the apparatus of the fourth embodiment of the present invention.

FIG. 14 is a diagram for explaining a displaceable range of a correction optical system in a conventional device of this type.

FIG. 15 is a diagram for explaining an operation range of a correction optical system in a conventional device of this type.

[Explanation of sign]

 CMR camera body LNS lens ILNS correction optical system ICPU image blur correction microcomputer AD angular displacement meter IACT image blur correction actuator ICNT image blur correction control circuit SH sample hold circuit

Claims (5)

[Claims] 1. An image forming optical system, a correction optical mechanism for decentering or tilting an optical axis of the image forming optical system, and an image blur for performing image blur correction on an image forming plane by driving the correction optical mechanism. An image blurring unit having two sets of driving units that are independently driven in two directions substantially orthogonal to each other in order to correct a two-dimensional image blurring occurring on the image plane. In the correction device, when the driving displacement command value of the correction optical mechanism by the two sets of driving means reaches a predetermined relationship, a limiting means for limiting the displacement in these two directions is provided. apparatus. 2. The image blur correction device according to claim 1, wherein the predetermined relationship is a relationship in which a combined displacement of two sets of driving means in a two-dimensional plane is substantially constant. 3. The image blur correction device according to claim 1, wherein the predetermined relationship is a relationship in which a sum of absolute values of drive displacements of the two sets of drive means is substantially constant. 4. An image forming optical system, a correction optical mechanism for decentering or tilting an optical axis of the image forming optical system, and an image blur for performing image blur correction on an image forming plane by driving the correction optical mechanism. The image-correction optical mechanism is provided with two sets of drive means that are independently driven in two directions substantially orthogonal to each other in order to correct a two-dimensional image blur generated on the image plane. In the correction device, when the drive displacement command value of the correction optical mechanism by the two sets of drive means reaches a first predetermined relationship,
An image blur correction device comprising drive control means for driving the two sets of drive means with signals obtained by combining the respective drive control signals in a second predetermined relationship. 5. An image forming optical system, a correction optical mechanism for decentering or tilting an optical axis of the image forming optical system, and an image blur for performing image blur correction on an image forming surface by driving the correction optical mechanism. Compensation means, exposure control means for exposing an image on the image plane to a film or an image pickup element, and trigger means for starting the operation of the exposure control means are provided, and the correction optical mechanism includes the image plane. An image blur correction device comprising two sets of driving means that are independently driven in two directions substantially orthogonal to each other in order to correct a two-dimensional image blur occurring above, in the correction optical mechanism by the two sets of driving means. When the drive displacement command value of 1 reaches a predetermined relationship, an image blur correction device is provided, which inhibits the operation of the trigger means to inhibit the start of the exposure operation by the exposure control means.