JP2701086B2 - Optical device and device for preventing image blur - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device such as a camera for preventing image blur caused by camera shake and the like, and a device for preventing image blur.

BACKGROUND OF THE INVENTION Conventionally, various apparatuses for correcting camera shake have been proposed, for example, Japanese Patent Application Laid-Open No. 63-49729.

In these methods, in order to prevent blurring of an image on an image plane caused by camera vibration, a method of moving the optical axis decentering means to be controlled by a feedback control mechanism to suppress image blurring is adopted. Have been.

For example, a camera shake vibration (usually a tilt vibration of the camera with respect to the photographing optical axis) is detected as an acceleration signal, and the acceleration signal is integrated by a signal processing system to obtain a speed signal (and a displacement signal). The optical axis decentering means is driven in a vibration suppressing direction (a direction in which apparent vibration of an image is suppressed).

FIG. 13 shows an example of the principle configuration of an image blur correction device including such a signal processing system. In FIG. 13, reference numeral 1 denotes an accelerometer, which corresponds to a photographing optical axis of a camera (not shown). The tilt is detected as an acceleration signal. The detected acceleration signal a is integrated into a speed signal v by a first integrator 2 and further converted into a displacement signal d by a second integrator 3.

Numeral 5 denotes an actuator for moving the optical axis decentering means 4 (usually an imaging lens system) of the camera which is provided so as to be movable in the radial direction in order to prevent image blur in the radial direction by inputting the displacement signal d. It operates to drive control.

Reference numeral 6 denotes a position detecting sensor which constitutes a position detecting means for detecting an actual position displacement of the optical axis eccentric means 4, and a signal from the position detecting sensor 6 is supplied to an input system of the actuator 5 via an operational amplifier 7. The feedback loop is configured to provide feedback so that the drive control of the optical axis eccentric means 4 corresponds to the vibration displacement.

On the other hand, many proposals have been made for an automatic focus adjustment (AF) device. 1) One-shot AF (or single AF): After focusing once, AF is prohibited.

2) Servo AF (or continuous AF): Performs AF repeatedly and repeatedly.

3) Moving object prediction servo AF: for a moving subject at high speed, the AF following delay occurring during the AF operation or the release operation is corrected.

Proposals have also been made for some AF modes, such as.

However, when responding to a camera or the like by combining the image blur correction device and the automatic focus adjustment device, the effect may not be sufficiently exhibited. That is, regarding the image blur correction device, in order to distinguish between camera shake and panning or framing change, the behavior of the blur is classified into several patterns to infer the photographer's intention, and thereby the image blur correction is performed. Attempts have been made to improve operability by performing processing such as changing the band.

On the other hand, in a camera having a plurality of AF modes, when used in a certain AF mode, a framing operation specific to that mode is often performed. For example, 1) One-shot AF often aims at a stationary subject, and usually involves only camera shake vibration.

2) In the servo AF, the framing change operation is large because the camera follows an object moving around irregularly.

3) In the moving object prediction servo AF, many subjects move in a certain direction, and the camera moves continuously in one direction, that is, panning.

 An operation like the following is conceivable.

However, in the past, the analogy of the blurring behavior in the AF mode was not performed, and the photographer's operation intention was analogized only from the blurring signal, so that the usability was not always good.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and provides an optical device capable of performing an appropriate image blur prevention operation according to a situation and a device for preventing image blur. It is assumed that.

(Features of the Invention) In order to achieve the above object, the present invention according to claim 1 includes a first automatic focusing mode and a second automatic focusing mode different from the first automatic focusing mode. Auto-focusing means to be switched, and image blur prevention different between when the auto-focusing means is switched to the first auto-focusing mode and when it is switched to the second auto-focusing mode. And a switching means for switching the image blur prevention means so as to perform the operation for the above.

Further, in order to achieve the above object, the present invention according to claim 2 is an automatic focusing mode which is switched between a first automatic focusing mode and a second automatic focusing mode different from the first automatic focusing mode. The image blurring device performs a different image blur preventing operation between when the focus adjusting unit is switched to the first automatic focus adjusting mode and when the mode is switched to the second automatic focus adjusting mode. An apparatus for preventing image blur having a switching means for switching the prevention means is provided.

Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIGS. 1 to 7 show a first embodiment of the present invention, and FIG. 1 is a diagram showing a main part according to the present invention.

In FIG. 1, CMR represents a camera body, and LNS represents a detachable interchangeable lens.

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

The CCPU is a microcomputer in the camera (hereinafter, referred to as a microcomputer), and is a one-chip microcomputer having a ROM, a RAM, and an A / D conversion function. The microcomputer CCPU in the camera performs a series of camera operations such as automatic exposure control, automatic focus adjustment, and film winding according to the camera sequence program stored in the ROM. For this purpose, the camera microcomputer CCPU 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, and the power supply line VL
Supply power to the lens LNS and the camera body CMR
An inter-lens communication buffer for the output from the lens to the lens LNS via the signal line DCL and the output from the lens LNS to the camera body CMR via the signal line DLC.

SNS is a focus detection line sensor (hereinafter simply referred to as a sensor) composed of a CCD, etc., and SDR is its drive circuit, which drives the sensor SNS according to the instruction of the microcomputer CCPU in the camera.
The image signal from the sensor SNS is taken in, amplified, and sent to the microcomputer CCPU in the camera.

Light from lens LNS is main mirror MM, focus glass P
G, enters the photometric sensor SPC via the pentaprism PP,
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 that switches the display of the camera's display member DSP based on data sent from the camera's microcomputer CCPU and communicates the on / off state of various camera operation members inside the camera by communication. Notify the microcomputer CCPU.

The switches connected to the above-mentioned circuit DDR are various external operation switches of the camera, one of which is SWAF for selecting AF mode such as one shot AF (single AF) or servo AF (continuous AF). This is a switch for switching. Then, the selected AF mode is displayed on the display member DSP.

The LED is a light-emitting diode that indicates the focus detection state in the viewfinder, and provides an indication such as lighting when in focus.

The switches SW1 and SW2 are linked to a release button (not shown). The switch SW1 is turned on by pressing the release button in the first stage, and the switch SW2 is turned on by pressing the release button up to the second stage. As will be described later, the microcomputer CCPU in the camera 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 with the switch SW2 turned on as a trigger. The switch SW2 is connected to the "interrupt input terminal" of the microcomputer CCPU in the camera. Even when the switch SW1 is turned on, the switch SW2 is turned on to interrupt the program even when the switch is turned on, and the process can immediately proceed to a predetermined interrupt program.

MTR1 is a motor for feeding the film, and MTR2 is a motor for mirror up / down and shutter spring charging. The forward and reverse rotations are controlled by the respective drive circuits MDR1 and MDR2.

MG1 and MG2 are shutter start curtain and rear curtain running start magnets, respectively, which are energized by amplification transistors TR1 and TR2, and are controlled by a microcomputer CCPU in the camera.

 Next, the configuration on the lens LNS side will be described.

The LCPU is a microcomputer in the lens, and is a one-chip microcomputer having ROM, RAM, and A / D conversion functions like the microcomputer CCPU in the camera. The microcomputer LCPU in the lens performs drive control of the focus adjustment lens FLNS and drive control of the diaphragm in accordance with a command sent from the camera body CMR via the signal line DCL.
In addition, various operation states of the lens (how much the focus adjustment optical system has been driven, how many stops have been stopped, etc.) and parameters (open F number, focal length, coefficients of defocus amount vs. extension amount, etc.) are signaled. Send to camera via line DLC.

FMTR is a drive motor for the focus adjustment lens FLNS, which rotates a helicoid ring (not shown) via a gear train,
The focus is adjusted by moving the FLNS back and forth in the optical axis direction.

FDR is a drive circuit of the motor FMTR, and controls forward / reverse rotation, brake, and the like of the motor FMTR in accordance with a signal from the microcomputer LCPU in the lens.

This embodiment shows an example of an inner focus type. When a focus adjustment command is sent from the camera body CMR, the motor FMTR is driven according to the drive amount and direction sent at the same time, and the focus is adjusted. The focus is adjusted by moving the adjustment lens FLNS in the optical axis direction. The focusing lens
The movement amount of the FLNS is monitored by a pulse signal of the encoder circuit ENCF and is counted by a counter in the microcomputer LCPU in the lens. When the predetermined movement is completed, the motor FMTR is controlled.

Therefore, once the focus adjustment command is sent from the camera body CMR, the in-camera microcomputer CCPU does not need to be involved in driving the lens at all until the driving of the lens is completed. Further, the content of the counter can be transmitted to the camera body CMR as needed.

When an aperture control command is sent from the camera body CMR, a known stepping motor DMTR for driving an aperture is driven in accordance with the number of aperture stages sent at the same time.

The ICPU is an image stabilization microcomputer that controls the image stabilization operation and controls the signal DCL and lens LN from the camera body CMR to the lens LNS.
The signal DLC from the S to the camera body CMR is input, 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 microcomputer ICPU
Takes the form of intercepting the communication between the two. Communication from the image blur correction microcomputer ICPU to the camera microcomputer CCPU is performed via the lens microcomputer LCPU.

ACC is an accelerometer (angular accelerometer, to be precise) for detecting lens shake, and sends an (angular) acceleration signal a to the integrator IMT1. The integrator INT1 integrates the (angular) acceleration signal a and converts the (angular) velocity signal v to an image blur correction microcomputer ICPU and an integrator.
Send to INT2. The integrator INT2 integrates the (angular) velocity signal v and outputs a (angular) displacement signal d.

A known high-pass filter HPF is provided at a stage subsequent to the integrator INT2. The charge release switch means SWHP of the capacitor C in the high-pass filter HPF, off switch SWR1 and off switch SWR2 resistor R ₄ of the resistor R ₂ is provided.

Here, the switch SWHP is connected to the high-pass filter HPF.
The high-pass filter HPF is reset by turning on the switch SWHP to release the charge of the capacitor C.

The switch SWR1 is a cutoff frequency changeover switch for the high-pass filter HPF. The cutoff frequency f of this high pass filter HPF is In it, R is the combined resistance value of the resistor R ₁ and R _2. And usually are in the switch SWR is opened, the cutoff frequency f ₁ at this time Becomes On the other hand, if the above switch SWR is closed Since the cutoff frequency f ₂ is higher than the previous f _1. That is, the ability to remove low frequency signals is enhanced.

The switch SWR2 is a switch for eliminating a change in gain of the film caused by the switching of the switch SWR1, and is switched in conjunction with the switch SWR1.

These switches SWHP, SWR1 and SWR2 are switched according to a flow described later, and the output d of the integrator INT2 is subjected to a predetermined process and output as d '. This signal d 'is input to the image blur correction microcomputer ICPU and the operational amplifier AMP.

The ILNS is a correction optical system that is an optical axis decentering means, is supported by a link mechanism described later, and can move substantially parallel to a plane perpendicular to the optical axis.

IMTR is an image blur correction motor that rotates the cam CAM fixed on the motor shaft forward and backward to displace the correction optical system ILNS.

IDR is a drive circuit of the image blur correction motor IMTR. The output signal from the operational amplifier AMP controls the motor IMTR to be positive or negative.
Drive in reverse.

PSD is a position detection sensor of the correction optical system ILNS, and light from the infrared light emitting diode IRED passes through a 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. The position detection sensor PSD generates a position of the incident light, that is, a position signal dL of the correction optical system ILNS. And this output signal (dL) is the microcomputer for image blur correction
The signal is input to the minus input terminals of the ICPU and the operational amplifier AMP.

SWIS is a main switch of the image blur correction operation circuit. When the switch SWIS is turned on, power is supplied to the microcomputer ICPU for image blur correction and its peripheral circuits, and then a reset signal RS
1, the integrators INT1 and INT2 are reset by RS2, and the shake signal is initialized. And switch S of camera body CMR
When W1 is turned on, this signal is communicated to the image blur correction microcomputer ICPU via the lens microcomputer LCPU, and the motor IM
TR is driven to start the image blur correction operation.

Although dL is assumed to be the position signal of the correction optical system ILNS, since the displacement of the correction optical system ILNS and the amount of optical axis eccentricity caused by this are proportional, dL may be regarded as the amount of optical axis eccentricity. No problem. The origin of this signal is a position where the central axis of the correction optical system ILNS coincides with the photographing optical axis.

In FIG. 1, the image blur correction mechanism is shown for only one axis, but since camera shake occurs in two-dimensional directions (up, down, left, and right), an actual lens detects blur in the two axes, and the correction optical system IL.
NS must also move in two dimensions.

FIG. 2 shows the support mechanism of the correction optical system ILNS in detail, and is a perspective view seen obliquely from the front on a horizontal plane including the optical axis. Normally, the blur is decomposed into two axes of a vertical direction (pitch) and a horizontal direction (yaw) to perform detection and blur correction, but in the present embodiment, in the I and J directions inclined at 45 ° with respect to the two directions. The reference axis for blur correction is set.

In FIG. 2, an arrow G indicates the direction of gravity, and 1i and 1j indicate angular accelerometers for detecting angular fluctuations in the I direction and the J direction of the photographing optical axis C, and correspond to ACC in FIG. The shake, that is, the angular acceleration ai is detected by the angular accelerometer 1i, and the shake in the J direction, that is, the angular acceleration aj, is detected by the angular accelerometer 1j. 31 is a fixed frame fixed to the taking lens body, 37 is a moving frame, plates 35 and 36
And 34, 38 to 40, are coupled to the fixed frame 31, and are movable in the direction of arrow di. Reference numeral 32 denotes a lens holding frame, which holds a correction optical system 33 (this corresponds to the ILNS in FIG. 1), is coupled to a moving frame 37 by plates 41, 42 and flexible tongues 43 to 46, and is attached to the moving frame 37. On the other hand, it can be moved in the direction of arrow dj.

Reference numeral 51 denotes a di-direction driving motor, which corresponds to the IMTR in FIG. 1 and is fixed to the flat portion 31i of the fixed frame 31 via the motor base 47.
A cam 52 (which corresponds to CAM in FIG. 1) and a pulley 53 are fixed to an output shaft 51a of the motor 51.
a comes into contact with the cam follower 54 attached to the moving frame 37,
By the rotation of the motor shaft 51a and the cam 52, the moving frame 37 is moved in the di direction. One end of a spring 56 is connected to the distal end of the wire 55 wound around the pulley 53, and the other end is hung on a spring hook 57 implanted in the moving frame 37, so that a contact between the cam 52 and the cam follower 54 is provided. The contact force F works. The reason why the pulley 53 and the wire 55 are used to generate the contact force is to prevent the torque from being generated in the cam 52 by the corresponding contact force, and the detailed mechanism has already been disclosed by the present applicant. Omitted.

Reference numeral 58 denotes a slit plate fixed to the moving frame 37.
Infrared light emitting diode (equivalent to IRED in Fig. 1)
A moving frame 37 is formed by a known method using a position detection sensor 59 (corresponding to the PSD in FIG. 1) 60 and a slit 58a of a slit plate 58.
To detect the position in the di direction.

Reference numeral 61 denotes a motor that drives the lens holding frame 32 in the dj direction, and is fixed to the flat portion 31j of the fixed frame 31 via the motor base 48.
A cam 62 and a pulley 63 are similarly fixed to the motor shaft 61a, and the cam 62 and the cam follower 64 are abutted by a wire 65, a spring 66, and a spring hook 67. Here, the cam follower 64 is provided not on the lens holding frame 32 but on the intermediate lever 71. The intermediate lever 71 is fixed to the fixed frame 31 via the flexible tongue 72.
, And swingable in the direction of the arrow θj. Intermediate bearings 73 and 74 are mounted on the lever 71, and the bearing is in contact with the flat portion 32 j of the lens holding frame 32. Therefore, the cam follower 64,
The intermediate lever 71 and the intermediate bearings 73 and 74 are integrally displaced in the θj direction, which causes the lens holding frame 32 to move in the dj direction. Since the displacement of the moving frame 37 in the di direction is absorbed between the flat portion 32j of the lens holding frame 32 and the intermediate bearings 73 and 74, interference between the movement in the di direction and the movement in the dj direction is avoided. A slit plate 68 is fixed to the lens holding frame 32, and the infrared light emitting diode 69 and the position detection sensor PSD7 are provided.
By 0, the displacement of the lens holding frame 32 in the dj direction is detected.

With the above configuration, the angular displacement of the lens in the I direction can be measured.
1i, the moving frame 37 and the lens holding frame 32 are driven in the di direction by driving the motor 51 based on the blur signal, and the blur in the J direction is detected by the angular accelerometer 1j. , The lens holding frame 32 is driven in the dj direction via the intermediate lever 71. Then, by these two-axis direction blur correction operations, two-dimensional blur on the shooting screen can be corrected.

Next, the displacement behavior in the angular direction when the camera is held at a certain position will be described with reference to FIG.

In each of the drawings in FIG. 3, the horizontal axis is time. The “blur displacement” indicates the blur displacement of the camera, which is an imaging device in which the camera body CMR and the lens LNS are integrated.
However, this represents the attitude (direction) of the camera with respect to the outside world, and this displacement is not directly detected.

"V" is a speed signal output by the first integrator INT1 in FIG. "D '" is a high-pass filter HPF
Is the displacement signal output, and the displacement signal actually detected is d '.

In the figure, these “blur displacements”, “v” and “d ′”
However, each of the AF modes of one-shot AF, servo AF, and moving object prediction servo AF is conceptually drawn.

Therefore, the displacement behavior in these AF modes and the processing method corresponding thereto in the embodiment of the present invention will be described in order.

 First, the one-shot AF will be described.

The one-shot AF is selected in many cases for photographing a still subject such as a portrait or a commemorative photograph, and therefore, no panning is performed. However, after the AF is completed, a so-called prefocus for changing the framing may be performed. FIG. 3 (a) shows this situation.
Although up to t ₁ has occurred only shake vibration, to start the framing changes from t _1, shows that ended t _4. FIG. 5V shows the speed signal at this time. When fully perform blur correction over the entire time domain where will cancels this by photographer even though the anti-shake operation conducted framing changes at time t ₁ ~t _4, framing changes in the finder screen It is not very easy to use. Therefore, in the present embodiment, attention is paid to the fact that the speed signal v becomes considerably large when the framing is changed, and when the speed v exceeds a certain limit value ± vth, the displacement d 'is reset so as to become "0". In other words, the speed v at time t ₂
Is greater than vth, it is determined that the framing has been changed, and the displacement d 'is set to "0" until the speed v becomes equal to or less than vth. Then, at time t ₃ | v | <to start the output of the displacement d 'If you become a vth. Therefore, the movement of the correction optical system ILNS becomes like the displacement d ', the image blur correction is prohibited during the framing change, the framing can be changed, and the image blur correction is performed at other times.

 Next, the servo AF will be described.

Servo AF is selected when shooting a subject whose focus is constantly changing, and the vertical, horizontal, and vertical movement of the subject is also irregular. Therefore, the camera shake displacement is shown in Fig. 3 (b).
As shown in the figure, the waveform becomes a waveform in which the camera shake vibration is superimposed on the low frequency large amplitude shake due to frequent framing changes. Therefore, in such a case, the cutoff frequency of the high-pass filter HPS is increased, and the effect of image blur correction on low-frequency blur caused by a framing change is weakened. As a result, the correction optical system ILNS does not react very much to low-frequency, large-amplitude blur as shown in FIG. Therefore, the framing can be changed smoothly without lowering the camera shake correction ability.

 Next, the moving object prediction servo AF will be described.

In many cases, the moving object prediction servo AF is selected, in which a subject that continuously approaches or moves away is photographed. Therefore, the camera is often used in a panning state. Therefore, the blur displacement at this time gradually changes in one direction as shown in FIG. 3 (c), and the camera shake is superimposed thereon. The speed detected at this time is as shown in FIG.
The displacement signal that has passed through F becomes like d '. Here, when the panning amount is small, the normal image blur correction operation may be performed. However, when the panning amount is large, the correction optical system ILNS uses up its effective stroke (collides with the inner wall of the lens barrel), and the subsequent image Shake correction becomes impossible. Therefore, in this embodiment, displacement signal d at time t ₅ 'is When exceeding the limit value dth, by increasing the cutoff frequency of the high-pass filter HPF, a displacement d by panning' prevents an increase in. Such processing does not reduce the camera shake correction ability and does not respond to the panning operation, so that the panning operation in the moving object prediction servo AF is not hindered.

Next, the camera body CMR and the lens LNS in the above configuration
Will be described with reference to flowcharts shown in FIGS. 1, 3, and 4.

When a power switch on the camera body CMR (not shown) is turned on, power supply to the microcomputer CCPU in the camera is started, and the microcomputer CCPU in the camera starts executing a sequence program stored in the ROM.

FIG. 4 is a flowchart showing the entire flow of the program on the camera body CMR side.

When the execution of the program is started by the above operation, the state of the switch SW1 which is turned on by pressing the release button in the first step is detected in step (002) through step (001), and to (003) when the switch is off. After the transition, clear all the control flags and variables set in the RAM of the microcomputer CCPU in the camera and initialize them. Step (004)
Clears the counter JFCNT that counts the number of times of focusing and the counter AFCNT that counts the number of times of AF operation. In the next step (005), a command to stop the image blur correction operation (IS) is transmitted to the lens LNS side.

The above steps (002) to (005) are repeatedly executed until the switch SW1 is turned on or the power switch is turned off.

When the switch SW1 is turned on, the process moves from step (002) to (010).

In step (010), lens communication 1 is performed. This communication is for obtaining information necessary for performing exposure control (AE) and focus adjustment control (AF). When the microcomputer CCPU in the camera sends a communication command to the microcomputer LCPU in the lens via the signal line DCL The microcomputer LCPU in the lens is a signal line DLC
, Information such as the focal length, the AF sensitivity, and the open F number stored in the ROM.

In step (011), a command to start the image blur correction operation is transmitted to the lens LNS side.

In step (012), a "photometry" subroutine for exposure control is executed. That is, the microcomputer CCPU in the camera inputs the output of the photometric sensor SPC shown in FIG. 1 to the analog input terminal, performs A / D conversion, and obtains the digital photometric value B
get v.

In step (013), an "exposure calculation" subroutine for obtaining an exposure control value is executed. In this subroutine,
According to the Apex calculation formula “Av + Tv = Bv + Sv” and a predetermined program diagram, determine the shutter value Tv and the aperture value Av,
These are stored in a predetermined address of the RAM.

Next, in step (014), an "image signal input" subroutine is executed. Here, the camera microcomputer CCPU inputs an image signal from the focus detection sensor SNS.

Subsequently, in step (015), the defocus amount of the photographing lens is calculated based on the input image signal.

The subroutine flow of the above steps (014) and (015) has been disclosed by the present applicant in Japanese Patent Application Laid-Open No. 63-18314, and a detailed description thereof will be omitted here.

In the next step (016), focus determination is performed. If it is in focus, the focusing counter JFCNT is advanced by one in step (017), and the process returns to step (002). If not in focus, the process proceeds to step (018).

In step (018), it is determined whether or not one-shot AF is performed. If it is one-shot AF, the flow proceeds to step (019).

In step (019), the number of focusing times JFCNT is determined, and JFCNT is determined.
If CNT = 0, that is, if focusing has not yet been performed once, the process proceeds to step (022) to drive the lens. When JFCNT ≧ 1, return to (002).

If it is determined in step (018) that it is not one-shot AF, the process proceeds to step (020) where servo AF is performed.
Then, if it is servo AF, the process proceeds to step (022) to drive the lens.

If it is determined in the above step (020) that it is not the servo AF, that is, that it is the moving object prediction servo AF, a moving object prediction calculation is performed in a step (021) to calculate the lens driving amount. Since the moving object prediction calculation is disclosed by the present applicant in Japanese Patent Application Laid-Open No. 1-205115, a detailed description thereof will be omitted.

Subsequently, in step (022), a "lens drive" subroutine is executed. In this subroutine, the number of drive pulses of the focusing lens FLNS calculated in the step (015) or (021) on the camera body CMR side is only transmitted to the microcomputer LCPU in the lens. Drive control of the motor FMTR according to the deceleration curve. After the driving is completed, an end signal is transmitted to the microcomputer CCPU in the camera, and this subroutine ends.

Next, in step (023), the AF number counter AFCNT
Is advanced by one, and the process returns to step (002).

Next, the above steps (014) to (023) surrounded by a broken line
A case where a release interrupt is generated by turning on the step SW2 during execution of each operation in the focus adjustment cycle shown in FIG.

The switch SW2 is connected to the microcomputer CCP in the camera as described above.
The switch is connected to the interrupt input terminal of U, and when the switch SW2 is turned on, the process immediately shifts to step (031) by the interrupt function regardless of which step is being executed.

If a switch SW2 interrupt is input during execution of a step surrounded by a broken line, it is determined whether or not one-shot AF is performed in step (032) via step (031). If it is not the one-shot AF, the flow shifts to the "release" subroutine of step (034), and the release operation is immediately performed.

When the one-shot AF is determined in step (032), the number of times of focusing JFCNT is determined in step (033). JFCNT =
0, that is, if focus has not yet been achieved, an interrupt is returned in step (036), and the AF operation is continued at least once until focus is achieved. On the other hand, if JFCNT ≧ 1, a release operation is performed in step (034). The operation of the "release" subroutine performed here will be described later with reference to FIG.

 In step (035), the film is wound up.

With the above operation, the shooting of one frame is completed, and the process returns to step (002).

Next, the "release" subroutine will be described with reference to FIG.

The mirror of the main mirror MM is raised in step (102) through step (101). This is executed by controlling the motor MTR2 via the drive circuit MDR2 shown in FIG.

In the next step (103), the step shown in FIG.
The aperture control value already stored in the "exposure calculation" subroutine of 13) is sent to the lens LNS side to perform aperture control.

In step (104), the previous steps (102) and (103)
It is determined whether or not the mirror-up and the aperture control have already been completed. The mirror up can be confirmed by a detection switch (not shown) attached to the main mirror MM, and the aperture control confirms by communication whether or not the lens has been driven to a predetermined aperture value. If any of them is not completed, the process waits at this step and continues to detect the state. When both controls are confirmed, the process proceeds to step (105). At this point, the preparation for exposure is complete.

In step (105), the shutter is controlled with the shutter control value already stored in the "exposure calculation" subroutine of the previous step (013), and the film is exposed.

When the control of the shutter is completed, in the next step (106), a command is sent to the lens LNS to open the aperture, and then the mirror is lowered in step (107). Mirror down is the same drive circuit as mirror up
This is executed by controlling the motor MTR2 via the MDR2.

In the next step (108), similarly to step (104), the control waits for the mirror down and aperture opening control to be completed. When both mirror down and aperture opening control are completed, step (10
Go to 9) and return.

Next, an image blur correction operation performed on the lens LNS side will be described with reference to the flowchart in FIG.

In step (201), the image blur correction main switch SWI
When S is turned on, power is supplied to the image blur correction microcomputer ICPU and its peripheral circuits.

In step (202), the two integrators INT1 and INT2 are reset, and their outputs v and d are initialized to “0”.

In step (203), an IS start command is determined. If no IS start command is received from the camera body CMR, step (2) is performed.
Go to 04).

In step (204), switch the high-pass filter HPF
SWHP is turned on (closed) to release the charge stored in the capacitor C and to prevent the charge.

Subsequently, in step (205), the switches SWR1 and SWR2 are turned off (open), and “0” is stored in the flag FLR representing the state of the switch SWR1.

Steps (203) to (206) are repeatedly executed while the IS start command does not come. In this state, the image blur correction is not performed, but the accelerometer ACC and the two integrators INT1 and INT2 are operating, and their outputs a, v, and d are continuously output.

When the IS start command is communicated from the camera body CMR, the process proceeds from step (203) to (211), where the microcomputer CCPU in the camera receives the AF mode. This communication is the fourth
This is a part of the communication performed in step (011) in the figure.

In step (212), only the integrator INT2 is reset to "0". This is because when the image blur correction is started from the step (214), the correction optical system ILNS uses the origin (the middle point of the movable range,
That is, the drive is started from the position where the central axis of the correction optical system ILNS coincides with the optical axis C in FIG. 1) so that the stroke can be used effectively.

In step (213), the switch SWHP is turned off (open), and the function of the high-pass filter HPF is started. At this time, since the switch SWR1 is off, the cutoff frequency of the high-pass filter HPF is This is a characteristic that allows a signal of a low frequency to pass.

In step (214), the drive circuit IDR of the motor IMTR is operated. A signal from an operational amplifier AMP that enables the circuit to operate is input, and the drive of the motor IMTR is controlled in accordance with the signal. Since the output d of the integrator INT2 is "0" at the start of the operation, the output d 'of the high-pass filter HPF is also "0". Therefore, amplifier AMP, drive circuit IDR
The motor IMTR controls the output so that the output of the position detection sensor PSD is “0”, that is, the correction optical system ILNS comes to the origin (movable center position). This is called a centering operation. After that, a displacement signal d corresponding to the shake is output from the integrator INT2, which passes through the high-pass filter HPF to become d 'and is input to the amplifier AMP. Accordingly, the displacement dL of the correction optical system ILNS is driven and controlled so that dL = d ', whereby the image on the imaging surface, that is, on the focus glass PG can be stopped.

In the next step (215), it is determined whether or not the AF mode sent by communication from the camera body CMR is one-shot AF. If it is the one-shot AF, the process proceeds to step (216).

In step (216), the speed v, which is the output of the integrator INT1,
Is compared with the speed limit value vth, and if | v | <vth, it is determined that only normal camera shake has occurred, and step (21)
Proceeding to step (219) via 8), determine whether or not an IS stop command has been transmitted from the camera body CMR. If not, return to step (215) and repeat the above loop. The normal image blur correction operation is continued.

If it is determined in step (216) that | v | ≧ vth, as apparent from the description of FIG.
Proceed to 7), where the integrator INT2 is reset and the switch SWHP is turned on. Then, since the displacement signals d and d 'both become "0", the correction optical system ILNS is centered so that dL = 0. During the period of | v | ≧ vth, the displacement signals d and d ′ continue to be “0” by the loop of steps (215), (216), (217), (219), and (215). Continue to be held in position. Then, when the framing change is completed and | v | <vth, the process proceeds again from step (216) to (218) to turn off the switch SWHP, and the integrator INT2 outputs the displacement signal d without being reset. , The normal image blur correction operation is restarted.

When the reception of the IS stop command is recognized in step (219) during execution of the above loop, the driving circuit I is detected in step (220).
Stop the DR, stop the image stabilization operation, and
Return to 3).

 Next, the flow of the servo AF will be described.

If it is determined in step (215) that it is not one-shot AF, the process proceeds to step (221), and if it is determined that it is servo AF, the process proceeds to step (222). Step (22
In 2) switches SWR1, SWR2 of the high-pass filter HPF is turned on (closed), switch the cutoff frequency of the highpass filter HPF to a higher value f ₂ than usual f ₁ for the reasons explained in FIG. 3 (b) .

In the next step (223), "1" is stored in the flag FLR representing the state of the switch SWR1, and the flow shifts to step (219).

That is, during servo AF, steps (215), (221), (22)
2) (223) (219) loop performs image blur correction at the (215), since this time the cut-off frequency of the high-pass filter HPF is set to a high value f _2, a relatively low frequency, such as framing change The response to the camera shake is dull, and the high frequency camera shake vibration is well corrected.

 Finally, the flow of the moving object prediction servo AF will be described.

NO in steps (215) and (221) during moving object prediction servo AF
Is determined, the process proceeds to step (231), where the state of the flag FLR representing the state of the switch SWR1 is determined. In the first flow after the switch SW1 is turned on, the flag FLR is "0" (the switch SWR is off) in step (206). In this case, the process proceeds to step (232), where the high-pass filter HPF The output displacement signal d 'is compared with the displacement limit value dth, and when the blur displacement is small, that is, |
If d '| <dth, the process proceeds to step (219) to continue the normal image blur correction operation.

If it is determined in step (232) that | d '| ≧ dth, that is, that a large panning operation has been performed, step (222)
To the high-pass filter HP as in the previous servo AF.
Increase the cutoff frequency of F so as not to hinder the panning operation. Then, even if the panning is continued, the value of d 'falls within a certain range, and the camera shake correction can be continued.

Then, once through steps (222) and (223), the flag FLR is set to "1".
When returning to, the process always goes through step (222). That is, in the moving object prediction servo AF mode, the normal image blur correction operation is performed when the amount of panning is small, and when the panning is large, the characteristic of the high-pass filter HPF is switched, so that the image blur correction does not work for panning. I have.

Next, the operation of the microcomputer LCPU in the lens will be described with reference to the flowchart of FIG.

When the power of the camera body CMR is turned on, power is started from the camera body CMR side to the lens LNS side via the mount contact between the lens and the camera body, and the lens microcomputer LCP
U starts executing a predetermined sequence program.

In step (302), SW1 is
Unless the ON signal is received, in step (303), all control flag variables set in the RAM in the microcomputer LCPU in the lens are cleared and initialized.

When the SW1 ON signal is transmitted from the camera body CMR side, the process proceeds to step (304), where "communication 1" is executed. This corresponds to “lens communication 1” in step (010) in FIG. 4, and transmits various information stored in the ROM of the microcomputer LCPU in the lens to the microcomputer CCPU in the camera.

When the microcomputer CCPU in the camera performs a focus detection calculation and transmits a lens drive command, it receives the command in step (305) and controls the drive of the focus adjusting lens FLNS in the next step (306).

When the lens drive is completed, a drive completion signal is transmitted to the microcomputer CCPU in the camera in step (307), and the process proceeds to step (30).
Return to 2).

While executing the above step (306), switch from the camera body CMR
When the 2 ON communication, that is, when the release start permission signal comes, the interruption is permitted and the step (311) is performed through the step (311).
Go to 2).

In step (312), the stop-down command is received. In step (313), the stop stepping motor DMTR is driven.
Perform a narrowing-down operation.

In step (314), driving of the focus adjustment lens FLNS is prohibited.

In step (315), the completion of the narrowing down is recognized, and this is transmitted to the microcomputer CCPU in the camera. Then
In response to this, the camera body CMR performs shutter control and performs film exposure.

When an aperture opening instruction is received from the microcomputer CCPU in the camera in step (316), the aperture opening operation is performed in the next step (317).

When the above-mentioned aperture opening operation is completed, step (318)
Transmits a completion signal to the microcomputer CCPU in the camera, and returns to step (302).

8 to 10 show a second embodiment of the present invention.

In the first embodiment described above, the characteristics of the high-pass filter HPF are switched uniformly during servo AF. In this case, it is effective for gradual framing changes, but abrupt framing changes include high frequency components due to framing blurring. May not be done.

Therefore, in the second embodiment, processing similar to that of the one-shot AF of the first embodiment is performed during the servo AF.

FIG. 8 is a diagram showing a main part according to the second embodiment. FIG. 8 differs from FIG. 1 in that a switch means SWV for controlling passage of a speed signal v is arranged between integrators INT1 and INT2. Is different. The switch SWV is connected to the microcomputer ICP for image blur correction.
On / off control is performed by U.

FIG. 9 is a flowchart at the time of the image blur correction operation in the second embodiment, and differs from FIG. 6 in the first embodiment in that step (207) is added after step (206). Only the point and the flow at the time of servo AF after step (221) are different. Therefore, only the changed part will be described.

If the IS start command has not been received in step (203), after executing steps (203), (205), and (206), the switch SWV is turned on (closed) in step (207), and the speed signal v Enable input to integrator INT2.

Steps (211) to (215) upon receiving the IS start command
Then, the process proceeds to step (221), and when it is determined that the servo AF is performed, the process proceeds to step (241).

In step (241), the speeds v and vth are compared, and | v |
If <vth, go to (219) via step (242),
Normal image blur correction is continued. If it is determined in step (241) that | v | ≧ vth, that is, framing has been changed, the switch SWV is turned off (open) in step (243).
And Then, the input to the integrator INT2 is cut off, and the output d is fixed to the value immediately before the switch SWV is turned off. The output d of the high-pass filter HPF 'attenuates the output at a time constant defined by the cut-off frequency f _1.

Then, the above steps (215) (221) (241) (243)
(219) The loop of (215) is repeated, during which the output d 'is attenuated, so that the correction optical system ILNS is also displaced slowly toward the movable center. Then, if | v | <vth during the execution of the above loop, steps (241) to (242)
Then, the image blur correction operation in which the switch SWV is turned on is restarted.

 FIG. 10 illustrates this operation.

In this figure, panning is detected at times t _{6 to} t ₇ , t _{8 to} t ₉ , and t _{10 to} t ₁₁ , and during that time, the input of the speed signal v is prohibited, so that displacement integration is not performed.

Here, the one shot of FIG. 3 in the first embodiment.
The difference from AF is that the centering of the correction optical system ILNS is performed when | v | ≧ vth in FIG. 3, whereas the centering is not performed in the second embodiment, so that when the image is observed with a finder, the image is not centered. There is no sudden movement of
Image continuity is maintained.

In the second embodiment, the flow of the moving object prediction servo AF is the same as that of the first embodiment, and the steps (222) (2) in FIG.
23) is (233) and (234) in FIG.

FIG. 11 and FIG. 12 show a third embodiment of the present invention.

In the first and second embodiments, the characteristic of the high-pass filter HPS is changed when the displacement d 'due to panning exceeds a certain value during the moving object prediction servo AF, and the blur correction is not performed for the low-frequency blur. Was something. However, the fact that the panning amount is large means that panning shooting is being performed, and in this case, it may be better not to perform image blur correction.

Therefore, in the third embodiment, the image blur correction is prohibited when the displacement d 'exceeds dth.

FIG. 11 is a flow chart of the image blur correction operation in the third embodiment. This embodiment is different from the second embodiment shown in FIG. The only difference is that (235) has been added.

That is, at the time of moving object prediction servo, in step (232) |
If it is determined that d ′ | ≧ dth, the switch SWR is turned on in step (233) to switch the characteristics of the high-pass filter HPS, and in the next step (234), “1” is stored in the flag FLR. At (235), the switch SWV is turned off to inhibit the input of the speed v to the integrator INT2.

As a result, as is apparent from FIG. 12, the correction optical system ILNS provides the cut-off frequency f ₂ of the high-pass filter HPF.
Slowly moves toward the movable center with a time constant corresponding to.

According to each of the above embodiments, in a camera having a plurality of AF modes, the set AF mode is determined and the third AF mode is determined.
As described in detail in FIGS. 10, 10 and 12, image blur correction processing is performed according to each AF mode, so that camera shake and framing change (panning) during viewfinder observation or shooting. Image blur correction suitable for each situation can be performed, and camera shake correction can be accurately performed without hindering operability of framing change (panning).

(Modification) According to the present embodiment, the servo AF and the moving object prediction servo AF have different flows. However, both may be the same flow, and even if the camera does not have the moving object prediction servo AF. I do not care. Further, although the setting of the AF mode is set by an external operation switch, a configuration in which the AF mode is automatically switched based on a plurality of focus detection results in the past may be used.

Further, in each of the above-described embodiments, an example in which the characteristics of the high-pass filter HPF is changed is shown as a method of switching the image blur correction characteristics. However, other methods, for example, a configuration in which the integration frequency band of the integrator is changed may be used. Absent.

(Correspondence between Invention and Embodiment) In this embodiment, the focus detection sensor SNS, the microcomputer CCPU in the camera, the switch SWAF, the motor FMTR, etc. are used as the automatic focus adjustment means of the present invention, and the correction optical system ILNS is used as the image blur of the present invention. Portions that execute steps 215 and 221 shown in FIGS. 6, 9, and 11 of the in-lens microcomputer LCPU correspond to the switching means of the present invention, respectively.

(Effects of the Invention) As described above, according to the present invention, an image blur prevention operation suitable for each automatic focusing mode can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a perspective view showing a correction optical mechanism, and FIGS.
(C) is a diagram for explaining the blur correction in each AF mode, FIGS. 4 to 7 are flowcharts showing the operation thereof, FIG. 8 is a configuration diagram showing a second embodiment of the present invention, and FIG. 9 is a flowchart showing the image blur correction operation, FIG. 10 is a diagram for explaining the blur correction at the time of servo AF, FIG. 11 is a flowchart showing the image blur correction operation in the third embodiment of the present invention, FIG. 12 is a diagram for explaining blur correction during moving object prediction servo AF, and FIG. 13 is a configuration diagram schematically showing a general image blur correction device. ACC, 1i, 1j …… Accelerometer, INT1, INT2 …… Integrator, ILNS…
… Correction optical system, CCPU …… Camera microcomputer, LCPU… Lens microcomputer, ICPU… Image blur correction microcomputer, PSD
…… Position detection sensor, AMM …… Op amp, SPC …… Photometry sensor, SW1, SW2, SWIS, SWHP, SWR1, SWR2 …… Switch, H
PF: High-pass filter, SNS: Focus detection sensor, I
RED …… Infrared light emitting diode, IMTR …… Motor, IDR ……
Drive circuit.

Claims (2)

(57) [Claims] 1. An automatic focus adjustment means for switching between a first automatic focus adjustment mode and a second automatic focus adjustment mode different from the first automatic focus adjustment mode, and wherein the automatic focus adjustment means is provided with the first automatic focus adjustment means. Switching means for switching the image blur prevention means so as to perform different operations for preventing image blur between when the mode is switched to the automatic focus adjustment mode and when the mode is switched to the second automatic focus adjustment mode. An optical device, comprising: 2. An auto-focusing device which is switched between a first auto-focusing mode and a second auto-focusing mode different from the first auto-focusing mode, comprises: An image characterized by comprising switching means for switching image blur prevention means so as to perform an operation for preventing image blur differently when the mode is switched and when the mode is switched to the second automatic focus adjustment mode. A device for preventing blurring.