Abstract:
A control device for an image blur correction which is applied to an image blur correction device that conducts image blur correcting operation in response to a signal corresponding to an output of a vibration detection sensor, includes a support state judging device for judging whether the device is in a predetermined support state or not, in accordance with the signal corresponding to the output of the vibration detection sensor, an operation state control device for changing the operating state of the image blur correction device in response to the judgment result by the support state judging means so as to set the operating state to a first state in which the image blur correction device does not conduct the given image blur correcting operation when the support state judging device judges that the device is in the predetermined support state, and to set the operating state to a second state in which the image blur correction device conducts the given image blur correcting operation in response to a judgement by the support state judging device that the device is released from the predetermined support state and a regulating device for regulating the shift of the state from the first state to the second state, when the predetermined operation of the camera starts, in response to a judgement by the support state judging device, which is responsive to the judgement by the support state judging device that the device is released from the predetermined support state.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a control device for image blur correction which is applied to an image blur correction device for correcting image blur occurring in an optical equipment, such as a camera. 
     2. Related Background Art 
     In existing cameras, because all important photographing operations, such as exposure or focusing operations, are automatically executed, the possibility that failure to perform a desired photographing operation will occur, even by a person not skilled in camera operation, is significantly reduced. 
     Also, in recent years, a system for preventing hand vibration which is applied to the camera has been studied, and factors that induce photographing error caused by the photographer now have almost been eliminated. 
     Now, an image blur correction device which prevents hand vibration will be described in brief. 
     Hand vibration of the camera at the time of photographing normally has a vibration frequency in the range of 1 to 12 Hz. A basic idea for taking a picture without image blur even if such hand vibration occurs at the time of a shutter release is that the vibration of the camera due to hand vibration is detected, and a correction lens is displaced in response to the detected value. Accordingly, in order that a photograph having no image blur can be taken even if the vibration of the camera occurs, it is necessary to first detect vibration of the camera with accuracy and then to correct for image displacement in an optically axial direction due to the hand vibration. 
     The detection of the vibration (camera vibration) can be theoretically performed by installing in the camera a vibration detection device comprised of a vibration sensor that detects an angular acceleration, an angular velocity, an angular displacement and the like, and a camera vibration detecting circuit that electrically or mechanically integrates the output signals of the vibration sensor so as to output a signal indicating the angular displacement. Then, image blur is corrected by driving a correction optical device that decanters the photographic optical axis on the basis of the above detection information. 
     Now, an outline of an image blur prevention system having a vibration sensor will be given with reference to FIG.  8 . FIG. 8 is a schematic diagram showing an image blur correction device that suppresses image blur caused by a camera vertical vibration  81   p  and a camera horizontal vibration  81   y  in a direction indicated by an arrow  81 , in the case where the image blur correction device is mounted on an interchangeable lens of a single-lens reflex camera. 
     In FIG. 8, reference numeral  82  denotes a lens barrel, and  83   p  and  83   y  are vibration detection devices which detect the camera vertical vibration and the camera horizontal vibration, respectively, where the respective vibration detection directions are indicated by reference symbols  84   p  and  84   y . Reference numeral  85  denotes a correction optical device (reference symbols  86   p  and  86   y  denote coils which give thrust in two directions to the correction optical system  85  in the two directions, respectively, and  87   p  and  87   y  are position detecting elements that detect the position of the correction optical device  85  in the two directions, respectively), and the correction optical device  85  is formed with a position control loop and driven with outputs from the vibration detection devices  83   p  and  83   y  as desired values so as to ensure stability at an image surface  88 . 
     FIG. 9 is an exploded perspective view showing an example of the structure of the above-described correction optical device  85 , which will be described below. 
     A back surface projected ear  71   a  of a base plate  71  is inserted into a lens barrel (not shown), and a known lens barrel roller or the like is screwed into a hole  71   b  so as to be fixed to the lens barrel. A second yoke  72  made of magnetic substance is screwed into a hole  71   c  of the base plate  71  by a screw that threads through the hole  72   a  of the second yoke  72 , and permanent magnets (shift magnets)  73  such as neodymium magnets are magnetically adsorbed to the second yoke  72 . Coils  76   p  and  76   y  (shift coils) are inserted into a support frame  75  to which a correction lens  74  is fitted by a C-ring or the like. A first yoke  712  is inserted into positioning holes  712   a  by respective pins of the base plate  71 , and the first yoke  712  is magnetically coupled at its backing surface to the base plate  71  by a magnetic force of the permanent magnets  73 . 
     One end of an L-shaped shaft  711  is inserted into a bearing portion  75   d  of the support frame  75 , and the other end of the L-shaped shaft  711  is inserted into a bearing portion  71   d  formed in the base plate  71 . Also, the shaft  711  is slidably supported only in directions indicated by arrows  713   p  and  713   y  with respect to the base plate  71 , to thereby regulate the relative rotation (rolling) about the optical axis with respect to the base plate  71  of the support frame  75 . 
     The coils  76   p  and  76   y  are located within respective closed magnetic circuits formed of the permanent magnets  73 , the first yoke  712  and the second yoke  72 . In this arrangement, when a current is permitted to flow in the coil  76   p , the support frame  75  is driven in the direction indicated by the arrow  713   p , whereas when a current is permitted to flow in the coil  76   y , the support frame  75  is driven in the direction indicated by the arrow  713   y.    
     When the support frame  75  moves on a plane perpendicular to the optical axis, an incident position of a light emitted from light projecting elements  77   p  and  77   y  and passing through slits  75   ap  and  75   ay  is changed on the position detecting elements  78   p  and  78   y . In general, when the outputs of the position detecting element  78   p  and  78   y  are amplified by ICs  731   p  and  731   y  and the coils  76   p  and  76   y  are driven by the amplified outputs, the support frame  75  is driven so that the outputs of the position detecting elements  78   p  and  78   y  are changed. In this example, the-drive directions (polarities) of the coils  76   p  and  76   y  are set so that the outputs of the position detecting elements  78   p  and  78   y  become small (negative feedback), the support frame  75  is stabilized by the drive forces of the coils  76   p  and  76   y  at a position where the outputs of the position detecting elements  78   p  and  78   y  become substantially zero. 
     The above-mentioned method of driving the support frame  75  by negatively feeding back the position detection output is called “position control manner”, and for example, when a desired value (for example, a hand vibration angle signal) is mixed with the ICs  731   p  and  731   y  from an external source, the support frame  75  is extremely faithfully driven in accordance with the desired value. 
     Actually, the outputs of differential amplifiers  731   cp  and  731   cy  are supplied to a main substrate (not shown) through a flexible substrate  716 , subjected to A/D conversion and then taken in a microcomputer (not shown). 
     The A/D converted outputs are appropriately compared with the desired value (hand vibration angle signal) and amplified within the microcomputer, and then subjected to leading phase compensation (for more stabilizing position control) through a known digital filter manner. Thereafter, the signals subjected to the leading phase compensation again pass through the flexible substrate  716 , and are then input to an IC  732  (for driving the coils  76   p  and  76   y ). The IC  732  conducts known PWM (pulse width modulation) drive on the coils  76   p  and  76   y  on the basis of the input signals to drive the support frame  75 . 
     Also, when the correction optical device is not operated, it is necessary to lock the support frame  75 . Three projections (not shown) are disposed on a back surface of the support frame  75 . The leading edges of those projections are inserted into the inner peripheral surface of a lock ring  719  so that the support frame  75  is fixed. Specifically, when electricity is supplied to a coil  720  through a magnetic circuit consisting of the coil  720  and a lock magnet  718 , the lock ring  719  rotates against a lock spring  728 , an armature  724  is abutted against an adsorption yoke  729  and electricity is supplied to an adsorption coil  730 , as a result of which the armature  724  is adsorbed by the adsorption yoke  729 . In this situation, when the supply of electricity to the coil  720  stops, the lock ring  719  is going to return to an original position due to the force of the lock spring  728 . However, because the armature  724  is adsorbed by the adsorption coil  729 , rotation is regulated, thereby leading to a lock release state. In the case of returning to a lock state, the supply of electricity to the adsorption coil  730  stops so that the lock ring  719  rotates due to the force of the lock spring  728 , and the projections of the support frame  75  are inserted into the inner peripheral surface of the lock ring  719 , to thereby come to the lock state. 
     FIG. 10 is a block diagram showing the electric schematic structure of the image blur correction device. 
     The output of an image blur detection device  2  is processed by a signal processing circuit  3  that executes amplification, high-pass filtering, low-pass filtering and so on, converted into a digital signal by an A/D conversion portion  4  within a microcomputer  1 , and then subjected to data processing such as offset removal, high-pass filtering and integration by a data processing portion  5 . Also, the output of a position detection device  6  that conducts the position detection of the correction lens is processed by a signal processing circuit  7  that conducts low-pass filtering and so on, converted into a digital signal by an A/D conversion portion  8  within the microcomputer  1  and then subjected to data processing such as amplification by a data processing portion  9 . Then, those two signals are calculated by a feedback calculation portion  10  and subjected to amplification and known leading phase compensation by a leading phase compensation portion  11 . Then, a drive signal of the correction lens is output to a port of the microcomputer  1 , and the correction lens is driven by a correction lens driving device  12  to perform image blur correction. 
     Also, when image blur correction is not conducted, the correction lens is brought into the lock (engagement) state, whereas when image blur correction is conducted, it is brought into the unlock state. A lock/unlock driving device  13  is designed so as to drive the correction lens. 
     Then, image blur correction has an optimum characteristic which is adapted to various circumstances such as a case in which a user performs photography while holding a camera by hand or a case in which the user performs photography while the camera is held by a tripod. For example, in the case of a single-lens reflex camera, when the user performs photography while holding the camera by hand, a characteristic of the image blur correction may be set so as to correct even vibration of a low frequency produced by hand vibration. On the other hand, when the user performs photography while the camera is held by a tripod, since no vibration of a low frequency occurs, a characteristic of the image blur correction may be set so as to correct only vibration of a high frequency produced by a quick return mirror and a shutter of the camera. This is because the photographing result is deteriorated by the drifting of a vibration sensor if low frequency correction is effected. In view of this fact, it has been proposed that the support state of the camera be detected, and the image blur correction characteristic be set in accordance with the detected support state. 
     As one method of detecting the support state of the camera, there is a method of conducting the detection in accordance with a signal level of the vibration sensor. This method is designed so that if the signal level of the vibration sensor within a given period of time is smaller than a predetermined value, the camera holding state is judged as a tripod support state. In this situation, a timing at which the tripod detection starts may be set to the half-depression operation of a release button so as to be synchronized with the photographing intention of the user. 
     In this example, if the user completely depresses the release button of the camera from a half-depression state to shift the operation to release operation, the mirror and the shutter are driven. However, if such operation is conducted in the tripod support state, the level of the vibration sensor signal is caused to exceed the tripod detection level due to the impact of the mirror and shutter drive, as a result of which there is the possibility that it is detected that the camera is supported by hand, although the camera is in fact supported by a tripod. 
     Also, in a camera system of the interchangeable lens type, since photographing is enabled without driving a mirror or shutter, depending on the sort of a camera attached to the interchangeable lens having an image blur correction function, it is necessary that the control of tripod detection during photographing is most preferably changed in accordance with the attached camera. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to solve the above problems associated with the prior art, and therefore has as an object thereof to provide a control device for image blur correction which prevents the operating state of an image blur correction device from being unintentionally changed over due to an influence of a predetermined operation of a camera. 
     In order to achieve the above object, according to one aspect of the present invention, there is provided a control device for image blur correction which is applied to an image blur correction device that conducts an image blur correcting operation in response to a signal corresponding to an output of a vibration detection sensor, where the control device comprises: 
     support state judging means which judges whether the device is in a given support state or not, in accordance with the signal corresponding to the output of the vibration detection sensor; 
     operation state control means which changes the operating state of the image blur correction device in response to the judgement result by the support state judging means so as to set the operating state to a first state, in which the image blur correction device does not conduct the given image blur correcting operation when the support state judging means judges that the device is in the given support state, and to shift the operating state to a second state, in which the image blur correction device conducts the given image blur correcting operation in response to a judgement by the support state judging means that the device is released from the given support state; and 
     regulating means which regulates the shift of the state from the first state to the second state, when the predetermined operation of the camera starts, in response to a judgement by the support state judging means, which is responsive to the judgement by the support state judging means that the device is released from the given support state. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing the structure of an interchangeable lens for a single-lens reflex camera in accordance with a first embodiment of the present invention; 
     FIG. 2 is a flowchart showing the main operation of a lens MPU shown in FIG. 1; 
     FIG. 3 is a flowchart showing a part of an image blur correction control operation in accordance with the first embodiment of the present invention; 
     FIG. 4 is a flowchart showing the subsequent operation of FIG. 3; 
     FIG. 5 is a flowchart showing a part of an image blur correction control operation in accordance with a second embodiment of the present invention; 
     FIG. 6 is a flowchart showing a part of an image blur correction control operation in accordance with a third embodiment of the present invention; 
     FIG. 7 is a flowchart showing a part of an image blur correction control operation in accordance with a fourth embodiment of the present invention; 
     FIG. 8 is a perspective view for explanation of the structure of a conventional image blur correction device; 
     FIG. 9 is an exploded perspective view showing an example of the conventional image blue correction device; and 
     FIG. 10 is a block diagram showing an example of the electric structure of the conventional image blur correction device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, a description will be given in more detail of preferred embodiments of the present invention with reference to the accompanying drawings. 
     (First Embodiment) 
     FIG. 1 is a block diagram showing the schematic structure of an optical equipment in accordance with a first embodiment of the present invention. In this embodiment, a case is assumed in which the interchangeable lens for a single-lens reflex camera is applied as an example of the optical equipment. 
     Referring to FIG. 1, reference numeral  31  denotes a lens MPU which controls lens side operation through communication with a camera. Reference numeral  32  denotes a vibration sensor that detects vibration (showing an example using an angular velocity sensor in the following embodiment). An output signal from the vibration sensor  32  has a d.c. component cut off through a high-pass filter and is subjected to amplification and low-pass filtering for noise removal through an HPF, amplifying and LPF circuit  33 , and is thereafter input to an A/D conversion terminal of the MPU  31 . Also, an output of a lens position detection device  34  that conducts the position detection of the correction lens is subjected to processing such as filtering through a signal processing circuit  35  and then input to an A/D conversion input terminal of the MPU  31 . Those two vibration signal and position detection signal are subjected to feedback calculation through the MPU  31  and drive the correction lens through a coil driver  36 , to thereby correct image blur. 
     Also, when image blur correction is not conducted, the correction lens is locked, but when image blur correction is conducted, the correction lens is unlocked (released from locking). The structure for achieving this operation is the same as that shown in the conventional example and the lock/unlock operation is conducted through a motor driver  37 . 
     Also, in addition to the above-described image blur correction control the MPU  31  drives a focus lens and an aperture through a zoom focus position detection device  38  and motor drivers  39  and  40 . 
     Reference numeral  41  denotes an operation select switch (ISSW) that selects whether image blur correction (image stabilization) is conducted or not, and numeral  42  denotes a switch (A/MSW) that selects whether automatic focusing or manual focusing is conducted. 
     The above-described lens MPU  31  conducts camera/lens communication with a camera MPU  43  to confirm the respective statuses of the camera and the lens (a focal distance, the switch state and so on) and transmits a drive command for the focusing, aperture and so on. 
     Reference numeral  44  denotes a release button which is generally formed of a two-stroke switch such that a switch SW 1  turns on by a first stroke (half depression) of the release button  44 , and a release switch SW 2  turns on by a second stroke (complete depression). 
     Subsequently, the specific operation of the above-described lens MPU  31  will be described with reference to a flowchart shown in FIG.  2 . In this first embodiment, it is assumed that the detection of a tripod starts when the above switch SW 1  turns on. 
     When a lens is attached to the camera, a serial communication from the camera MPU  43  to the lens MPU  31  is conducted, and the lens MPU  31  starts to operate from step # 1 . 
     First, instep # 1 , initial setup for lens control and image blur correction control is conducted, and in succeeding step # 2 , the states of the ISSW  41  and the A/MSW  42  are detected, and the zoom or focus state of the lens is detected by the zoom/focus position detection device  38 . Then, in succeeding step # 3 , it is judged whether a demand for focus driving has been transmitted from the camera MPU  43  or not. If a demand for the focus driving has been received, processing is advanced to step # 4 , and since the drive amount of the focus lens is instructed from the camera MPU  43 , the motor driver  39  is driven in response to the instructed drive amount to conduct the focus driving control. 
     Also, if a demand for focus driving has not been received in the above step # 3 , processing is advanced to step # 5 , in which the motor driver  37  is driven in response to the communication from the camera MPU  43  and the state of the ISSW  41  to control lock and unlock operation and to set an image blur correction start flag IS_START. Then, in succeeding step # 6 , it is judged whether a whole driving stop (the whole drive of the actuators within the lens stops) command has been received from the camera MPU  43  or not. If nothing is operated at the camera side, the whole driving stop command is transmitted from the camera MPU  43  after a short time. Then, processing is advanced step # 7  to conduct whole driving stop control. In this step, whole actuator driving is stopped, and the lens MPU  31  is brought into a sleep (stop) state. Also, the supply of electricity to the image blur correction device is stopped. Thereafter, when something is operated at the camera side, the camera MPU  43  transmits a communication to the lens MPU  31  to release the sleep state. 
     If a demand for serial communication interruption or image blur correction interruption is received through a communication from the camera during the above operation, those interruption processings are executed. 
     The serial communication interruption processing decodes communication data and conducts lens processing such as aperture driving in accordance with the decoded result. Then, the turn-on of the switch SW 1 , the turn-on of the release switch SW 2 , a shutter time, the type of the camera and so on can be discriminated in accordance with the decoded communication data. As a result, detection of a tripod can start upon turning on the switch SW 1  of the camera, and detection of a tripod can be interrupted upon turning on the release switch SW 2 . The detailed operation will be described later. 
     Also, image blur correction interruption is timer interruption occurring every given period (for example, 500 μsec). Then, since a pitch direction (longitudinal direction) control and a yaw direction (lateral direction) control are alternately conducted, a sampling period in one direction in this case becomes 1 msec. Also, since there are many identical portions in the control method with respect to each of these directions, only one system of program is prepared. Since the calculated result has different data between the pitch direction and the yaw direction, although the control method (calculation coefficient or the like) is identical therebetween, the respective reference addresses are set in the pitch direction and the yaw direction, data such as calculated result is designated by an indirect address of a RAM, and the reference address is switched over between the pitch control time and the yaw control time to thus conduct calculation. 
     If image blur correction interruption occurs during the main operation of the camera, the lens MPU  31  starts image blur correction control in step # 11  of a flowchart shown in FIG.  3 . The operation of detecting a tripod is also conducted in this image blur correction interruption. 
     First, in step # 11 , the output of an angular velocity sensor, which is vibration sensor  32  in the present application, is subjected to A/D conversion. In succeeding step # 12 , the judgement of the image blur correction start flag IS_START is made, and if the image blur correction start flag has been cleared, processing is advanced to step # 13 . Since image blur correction is not conducted, high-pass filtering and integral calculation are initialized, and processing is advanced to step # 25 , shown in FIG.  4 . 
     On the other hand, if the image blur correction start flag is set, processing is advanced to step # 14 , and a high-pass filter calculation is conducted in order to carry out image blur correction. Also, a time constant is switched over for 2 to 3 seconds after the start of image blur correction, and image blur at rising time is relaxed. Also, the time constant is changed in accordance with the condition in which the camera is supported, by tripod or hand. 
     In succeeding step # 15 , it is judged whether the switch SW 1  has been turned on or not. If the switch SW 1  is on, processing is advanced to step # 16  in order to start tripod detection to conduct high-pass filter calculation. In this example, high-pass filter calculation higher in cut-off frequency than the high pass filter calculation in the above step # 14  is conducted. This is to remove drifting of the vibration sensor  32  as much as possible. Then, in succeeding step # 17 , low-pass filter calculation is conducted. This is to remove the noise component. 
     In succeeding step # 18 , it is judged whether the release switch SW 2  has been turned on or not, and if the release switch SW 2  is not on, processing is advanced to step # 19  and subsequent steps to start a tripod detection operation. On the other hand, if the release switch SW 2  is on, processing is advanced to a step # 24  to interrupt the tripod detection operation. 
     In step # 19 , comparison is made whether the calculated result in the above step # 17  exceeds the maximum value or the minimum value of the previous sampling or not, and if it exceeds either value, the maximum value or the minimum value is updated. Then, in succeeding step # 20 , it is judged whether a difference between the maximum value and the minimum value is smaller than a predetermined value D or not, and if the former is smaller than the latter value, processing is advanced to step # 21 , in which since the difference between the maximum value and the minimum value is smaller than the predetermined value D, judgement is made that the camera is supported by a tripod (S_KYAKU flag=1). Also, if the difference between the maximum value and the minimum value is larger than the predetermined value D, processing is advanced from step # 20  to step # 22 , in which since the difference between the maximum value and the minimum value is larger than the predetermined value D, judgement is made that the camera is supported by hand (S_KYAKU flag=0). 
     Also, if the switch SW 1  is not on in the above step # 15 , processing is advanced to step # 23 , in which the high-pass filtering, the low-pass filtering, the maximum and the minimum values for detection of the use of a tripod are initialized, and processing is advanced to the above-described step # 22 . 
     In step # 24 , the set characteristics (also including a case in which the image blur correction characteristic is changed depending on the fact that the camera is supported by tripod or hand) are subjected to integral calculation. As the integral characteristics, in case of holding the camera by hand, in order to correct vibration of a low frequency caused by hand vibration, the characteristic is set to an integral characteristic for integrating even: the low frequency component. In case of holding the camera by tripod, in order to correct only vibration of a high frequency caused by the quick return mirror and the shutter of the camera without correcting vibration of a low frequency component caused by hand vibration, the characteristic is set to an integral characteristic for integrating only the high frequency component. 
     As a result, the characteristics become angular displacement data θ. In the case where panning is made, the cut-off frequency of integration is switched over in accordance with the vibration angle displacement. In succeeding step # 25  of FIG. 4, since the eccentricity (sensitivity) of the correction lens to the vibration angle displacement is changed depending on the position of zoom/focus, adjustment is made. Specifically, the positions of zoom and focus are divided into several zones, respectively, and an average vibration isolation sensitivity (deg/mm) in each zone is read from table data and converted into correction lens driving data. The calculated result is stored in a RAM region set in SFTDRV within the lens MPU  31 . 
     In succeeding step # 26 , the output of the lens position detection device  34  that conducts the position detection of the correction lens is subjected to A/D conversion, and the A/D converted result is stored in the RAM region set in SFTPST within the lens MPU  31 . Then, in step # 27 , feedback calculation (SFTDRV-SFTPST) is conducted, and in succeeding step # 28 , a loop gain is multiplied by the calculated result in the above step # 26 , and in succeeding step # 29 , phase compensation calculation is conducted in order to provide a stable control system. Finally, in step # 30 , the result in the above step # 29  is output to a port of the lens MPU  31  as PWM to complete interruption. 
     The output from the port of the above lens MPU  31  is input to the coil driver  36 , and the correction lens is driven by a moving magnet to correct image blur. 
     As described above, the operation of detecting the use of a tripod starts in response to turning-on of the switch SW 1  of the camera in step # 15 , and the operation of detecting the use of a tripod is interrupted by a judged result that the release switch SW 2  is on in step # 18 . Therefore, misdetection that the camera supported by a tripod is in the hand support state, which is caused by the fact that the mirror driving impact and the shutter driving impact during photographing adversely affect the angular velocity sensor signal, can be reliably prevented without provision of any special means. 
     Also, in the above first embodiment, an example in which the detection of the use of a tripod is interrupted by turning on the release switch SW 2  is described. Alternatively, if the judgement that the release switch SW 2  is on in step # 18  is changed to the judgement of whether a film is being fed or not, such mis-detection that the camera supported by a tripod is in a hand support state, which is caused by the fact that vibration caused by film feeding adversely affects the angular velocity sensor signal, can be reliably prevented. 
     Also, even judgement by the pop-up operation of a strobe built into the camera can obtain the same effect. 
     (Second Embodiment) 
     A second embodiment of the present invention is also applied to an interchangeable lens for a single lens reflex camera as in the above-described first embodiment, in which the operation of detecting the use of a tripod starts upon turning on the switch SW 1  of the camera, and the judgement level of detecting the use of a tripod is changed upon turning on the release switch SW 2 . Also, a method of detecting the use of a tripod is that judgement is made that the camera is supported by a tripod if the maximum value of an angular velocity sensor is smaller than a predetermined value D 1  or D 2 . 
     FIG. 5 is a flowchart showing the operation of a main portion of the interchangeable lens side of the single-lens reflex camera in the second embodiment of the present invention, in which the same parts as those of the above first embodiment in FIG. 3 are designated by identical step numbers, and their description will be omitted. Also, since the operation shown in FIG.  5  and other figures is completely identical with that of the above first embodiment in FIG. 4, its description will be also omitted. It is assumed that the circuit structure of the single-lens reflex camera is identical with that shown in FIG.  1 . 
     Parts different from the flowchart of the above-described first embodiment in FIG. 3 are steps # 31  to # 36  and therefore these steps will be described in detail. 
     In step # 31 , comparison is made whether the calculated result in the above step # 17  exceeds the maximum value of the previous sampling or not, and if it exceeds the value, the maximum value is updated. Then, in succeeding step # 32 , it is judged whether the release switch SW 2  has been turned on or not, and if the release switch SW 2  is not on, processing is advanced to step # 33 , in which it is judged whether the maximum value is smaller than the predetermined value D 1  or not. As a result, if the maximum value is smaller than a predetermined value D 1 , processing is advanced to step # 35 , and if the maximum value is larger than the predetermined value D 1 , processing is advanced to step # 36 . 
     If the release switch SW 2  is on in the above step # 32 , processing is advanced to step # 34 , in which it is judged whether the maximum value is smaller than a predetermined value D 2  or not. If the maximum value is smaller than a predetermined value D 2 , processing is advanced to step # 35 , and if the maximum value is larger than the predetermined value D 2 , processing is advanced to step # 36 . In this example, if the value of the predetermined value D 2  is set to be larger than the amount of vibration occurring during a photographing operation of the camera, mis-detection of a tripod support detection which is caused by vibration occurring during the photographing operation can be prevented. 
     When processing is advanced to step # 35 , since the maximum value is smaller than the predetermined value D 1  or D 2 , judgement is made that the camera is supported by a tripod (S_KYAKU=1). Also, when processing is advanced to step # 36 , since the maximum value is larger than the predetermined value D 1  or D 2 , judgement is made that the camera is supported by hand (S_KYAKU=0). Thereafter, the operation of the above-described step # 24  and the following steps is executed. 
     According to the above-described second embodiment, the operation of detecting the use of a tripod starts in response to turning-on of the switch SW 1  in step # 15 , and the judgement level of detecting the use of a tripod is changed in accordance with the judged result of whether the release switch SW 2  is on or not in step # 32  (steps # 33  and # 34 ). Accordingly, mis-detection that the camera supported by a tripod is in the hand support state, which is caused by the fact that the mirror driving impact during a photographing operation and the shutter driving impact adversely affect the angular velocity sensor signal, can be reliably prevented without provision of any special means. 
     Also, an example in which detection of the use of a tripod is interrupted by turning on the release switch SW 2  is described. Alternatively, if the judgement that the release switch SW 2  is on in step # 18  is changed to the judgement of whether a film is being fed or not, mis-detection that the camera supported by a tripod is in the hand support state, which is caused by the fact that a vibration caused by film feeding adversely affects the angular velocity sensor signal, can be reliably prevented. 
     Also, even judgement by the pop-up operation of a strobe built into the camera can obtain the same effect. 
     In this embodiment, the support state detecting means is the lens MPU  31 , and its operation is represented by steps # 16 ,  17  and steps # 33  to # 36  in FIG.  4 . 
     Also, the support state detection control means is the lens MPU  31 , and its operation is represented by steps # 32  to # 34  in FIG.  4 . 
     (Third Embodiment) 
     A third embodiment of the present invention is also applied to an interchangeable lens for a single lens reflex camera as in the above-described first and second embodiments, in which the operation of detecting the use of a tripod starts upon turning on the switch SW 1  of the camera, and the operation of detecting the use of a tripod is interrupted or continued as it is in accordance with the mounted camera upon turning on the release switch SW 2 . 
     FIG. 6 is a flowchart showing the operation of a main portion of the interchangeable lens side of the single-lens reflex camera in the third embodiment of the present invention, in which the same parts as those of the above first embodiment in FIG. 3 are designated by identical step numbers, and their description will be omitted. Also, since the operation shown in FIG.  6  and other figures is completely identical with that of the above first embodiment in FIG. 4, its description will be also omitted. It is assumed that the circuit structure of the single-lens reflex camera is identical with that shown in FIG.  1 . 
     Parts different from the flowchart of the above-described second embodiment in FIG. 3 are steps # 41  to # 46 , and therefore these steps will be described in detail. 
     In step # 41 , judgement is made whether the release switch SW 2  has been turned on or not, and if the release switch SW 2  is not on, processing is advanced to step # 43 . Comparison is made whether the calculated result in the above step # 17  exceeds the maximum value or the minimum value of the previous sampling or not, and if the former exceeds the latter, the maximum value or the minimum value is updated. Then, in succeeding step # 44 , it is judged whether a difference between the maximum value and the minimum value is smaller than a predetermined value D or not. As a result, if the difference between the maximum value and the minimum value is smaller than the predetermined value D, processing is advanced to step # 45 , in which judgement is made that the camera is supported by a tripod (S_KYAKU=1). Also, if the difference between the maximum value and the minimum value is larger than the predetermined value D, processing is advanced to step # 46 , in which judgement is made that the camera is supported by hand (S_KYAKU=0). Thereafter, the operation of step # 24  and the following steps is executed. 
     Also, if the release switch SW 2  is on in the above step # 41 , processing is advanced to step # 42 , in which judgement is made whether the type of the mounted camera is a camera A or not, and if it is a camera A, the operation of the above-described step # 43  and the following steps is executed. If the type of the camera is not camera A, processing is advanced to step # 24 , in which the operation of detecting the use of a tripod is interrupted. 
     Specific examples of a camera A are a camera that does not drive a mirror, a camera that has little vibration during mirror driving or shutter driving, a digital camera, and so on, which are cameras that have little vibration during a photographing operation. 
     According to the above-described third embodiment, the operation of detecting the use of a tripod starts in response to turning-on of the switch SW 1 , and the operation of detecting the use of a tripod is interrupted or continued as it is in accordance with the judged result that the released switch SW 2  is on or not in step # 41  and the discriminated result of the type of the mounted camera in step # 42 . Accordingly, the optimum detection of the use of a tripod can be conducted in accordance with the type of the camera even during a photographing operation. 
     (Fourth Embodiment) 
     A fourth embodiment of the present invention is applied to an interchangeable lens for a single-lens reflex camera as in the above-described first to third embodiments, in which the operation of detecting the use of a tripod starts upon turning on the switch SW 1  of the camera, and the judgement level for detecting the use of a tripod is changed in accordance with the type of the mounted camera upon turning on the release switch SW 2 . 
     FIG. 7 is a flowchart showing the operation of a main portion of the interchangeable lens side of the single-lens reflex camera in the fourth embodiment of the present invention, in which the same parts as those of the above first embodiment in FIG. 3 are designated by identical step numbers, and their description will be omitted. Also, since the operation shown in FIG.  7  and other figures is completely identical with that of the above first embodiment in FIG. 4, its description will be also omitted. It is assumed that the circuit structure of the single-lens reflex camera is identical with that shown in FIG.  1 . 
     Parts different from-the flowchart of the above-described first embodiment in FIG. 3 are steps # 51  to # 58 , and therefore these steps will be described in detail. 
     In step # 51 , comparison is made whether the calculated result in the above step # 17  exceeds the maximum value of the previous sampling or not, and if so, the maximum value is updated. In succeeding step # 52 , it is judged whether the release switch SW 2  has been turned on or not, and if the release switch SW 2  is not on, processing is advanced to step # 54 , in which it is judged whether the maximum value is smaller than a predetermined value D 1  or not. If the maximum value is smaller than the predetermined value D 1 , processing is advanced to step # 57 , and if the maximum value is larger than the predetermined value D 1 , processing is advanced to step # 58 . 
     If the release switch SW 2  is on in the above step # 52 , processing is advanced to step # 53 , in which judgement is made whether the type of the mounted camera is a camera A or not, and if it is a camera A, processing is advanced to step # 56 , whereas if it is not a camera A, processing is advanced to step # 55 , in which the operation of detecting the use of a tripod is conducted with the judgement level for detecting the use of a tripod in accordance with the type of the mounted camera. 
     Specific examples of a camera A are a camera that does not drive a mirror, a camera that has little vibration during mirror driving or shutter driving, a digital camera, and so on, which are cameras that have little vibration during a photographing operation. 
     In step # 55 , judgement is made whether the maximum value is smaller than a predetermined value D 2  or not, and if the maximum value is smaller than the predetermined value D 2 , processing is advanced to step # 57  which will be described later, whereas if the maximum value is larger than the predetermined value D 2 , processing is advanced to step # 58 . Also, in step # 56 , judgement is made whether the maximum value is smaller than a predetermined value D 3  or not, and if the maximum value is smaller than the predetermined value D 3 , processing is advanced to step # 57 , which will be described later, whereas if the maximum value is larger than the predetermined value D 3 , processing is advanced to step # 58 . 
     In this example, if the values of the predetermined values D 2  and D 3  are set to be larger than the amount of vibration occurring during a photographing operation of the camera, mis-detection which is caused by vibration occurring during a photographing operation can be prevented. 
     In step # 57 , since the maximum value is smaller than the predetermined value D 1 , D 2  or D 3 , judgement is made that the camera is supported by a tripod (S_KYAKU=1). Also, in step # 58 , since the maximum value is larger than the predetermined value D 1 , D 2  or D 3 , judgement is made that the camera is supported by hand (S_KYAKU=0). Thereafter, the operation of the above-described step # 24  and the following steps is executed. 
     According to the above-described fourth embodiment, the operation of detecting the use of a tripod starts in response to turning-on of the switch SW 1  in step # 15 , and the judgement level for detecting the use of a tripod is changed in accordance with the judged result that the release switch SW 2  is on in step # 52  and the discriminated result of the type of the mounted camera in steps # 55  and # 56 . Accordingly, the optimum detection of the use of a tripod can be conducted in accordance with the type of camera even during a photographing operation. 
     According to the above-described respective embodiments, the support state detection operation is interrupted or the detection judgement level is changed by turning on the release switch SW 2 . Accordingly, mis-detection caused by vibrations such as mirror driving or shutter driving, except for hand vibration, can be prevented. 
     Also, in the case of a camera system of the interchangeable lens type, since the support state detection operation during a photographing operation is interrupted by the mounted camera, or the detection level is changed, the optimum support state detection can be conducted in accordance with the type of camera even during a photographing operation. 
     (Modified Example) 
     The above-described respective embodiments show examples in which the control device for image blur correction conducts digital control, but analog control may be conducted instead. 
     The above-described respective embodiments show examples in which the control device for image blur correction is equipped within an interchangeable lens together with a vibration detection sensor and a correction lens. As another example, the present invention may be applied to a type in which a vibration detection sensor is equipped within the camera, a correction lens is equipped within the interchangeable lens, and the output of the vibration detection sensor is transmitted from the camera side to the interchangeable lens side, and control shown in FIG.  3  and so on is conducted by a microcomputer within the camera. 
     Also, the above-described respective embodiments show examples in which the image blur correction device is built into the interchangeable lens. Alternatively, the image blur correction device may not be equipped within the interchangeable lens, but may be provided as an accessary which is inserted into a conversion lens attached to the front portion of the interchangeable lens. 
     Also, the present invention may be applied to a camera such as a lens shutter camera or a video camera, and further can be applied as another optical equipment, another device or a structural unit. 
     Also, in the above-described respective embodiments, an angular velocity sensor is employed as an example of the vibration sensor. However, any kind of vibration sensor can be applied if vibration can be detected, for example, an angular acceleration sensor, an acceleration sensor, a velocity sensor, an angular displacement sensor, and a displacement sensor, as well as a method of detecting image blur, per se. 
     Also, in the above-described respective embodiments, as the support state detecting method, there is shown a method of obtaining the difference between the maximum value and the minimum value of the vibration angular velocity. Alternatively, the vibration acceleration/displacement may be applied and not the difference of the maximum value and the minimum value but only the magnitude of the maximum value may be applied. Thus, any methods may be applied if the support state can be detected. 
     As described above, according to the above respective embodiments of the present invention, there can be provided a support state detection device or a camera with an image blur correction function, which can prevent the detection of the support state from being mistaken by using the output of the vibration detection means during given operation and can always detect the support state with accuracy. 
     Also, according to the above-described respective embodiments, there can be provided an interchangeable lens with an image blur correction function which is capable of always detecting the support state with accuracy even if a camera of a different type is mounted thereon. 
     Further, according to the above-described respective embodiments, there can be provided a camera with an image blur correction function or a device for image blur correction which can prevent improper image blur correction from being conducted even if detection of the support state is mistaken by using the output of vibration detection means during a given operation.